Abstract
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Adv Clin Exp Med. 2016 Jan-Feb;25(1):11-9. doi: 10.17219/acem/28998.
An Assessment of the Number of Cariogenic Bacteria in the Saliva of Children with Chemotherapy-Induced Neutropenia
QBRI study helps for early prevention of metabolic disorders
A study that could help in the early prevention of the development of metabolic disorders has been conducted by a group of scientists led by Dr. Abdelilah Arredouani from the Diabetes Research Centre at the Qatar Biomedical Research Institute (QBRI), a research institute of Hamad bin Khalifa University, and Dr. Mario Falchi from the Department of Twin Research at Kings College in London.
The research study offers insight into the biological mechanisms behind metabolic differences and may have an impact in helping identify predictive markers of insulin resistance, diabetes, and obesity, making preventative care possible in Qatar and beyond.
The research was recently featured in the prestigious journal 'Diabetes' and concluded that individuals with low levels of a specific salivary protein, alpha-amylase, which is produced by the salivary glands and released in saliva, may cause the body’s energy production sources to switch from sugars to fatty acids.
Dr. Arredouani, one of the authors of the paper, along with colleagues from England, Italy and France arranged the study by carefully selecting two groups of healthy women for the research project: one group of women with a low level of the salivary protein and one with a high level.
By using a technique called 'metabolomics profiling,' and advanced statistical analysis methods, the scientists used serum samples from the women to compare their metabolism and gain an instantaneous snapshot of the physiology of their whole body.Their research indicated a significant difference between the metabolic profiles of the two groups.
Dr. Arredouani said that interestingly, the difference between the two groups studied seems to be due mainly to differences in the use of fatty acids.The results suggest that low levels of salivary alpha-amylase somehow reduces the uptake of glucose, the primary source of energy for the cells, and therefore the body shifts towards fatty acids usage to derive energy.
“If confirmed in bigger studies, the outcome may have clinical importance.Thus, low salivary amylase individuals who chronically ingest starch, in the form of rice for example, as is the case in the Middle East region, should eventually be considered to be at-risk of developing metabolic disorders, and therefore preventive nutritional and behavioral counseling should be provided to them.”
Dr. Omar El Agnaf, acting executive director of QBRI, added: “This QBRI-supported study furthers our aim to take an integrative and multidisciplinary approach in providing crucial insights into a key healthcare concerns in Qatar. By participating in collaborative studies like this one, we hope to continue to advance knowledge and champion the cause of fostering innovation in research.”
The research study offers insight into the biological mechanisms behind metabolic differences and may have an impact in helping identify predictive markers of insulin resistance, diabetes, and obesity, making preventative care possible in Qatar and beyond.
The research was recently featured in the prestigious journal 'Diabetes' and concluded that individuals with low levels of a specific salivary protein, alpha-amylase, which is produced by the salivary glands and released in saliva, may cause the body’s energy production sources to switch from sugars to fatty acids.
Dr. Arredouani, one of the authors of the paper, along with colleagues from England, Italy and France arranged the study by carefully selecting two groups of healthy women for the research project: one group of women with a low level of the salivary protein and one with a high level.
By using a technique called 'metabolomics profiling,' and advanced statistical analysis methods, the scientists used serum samples from the women to compare their metabolism and gain an instantaneous snapshot of the physiology of their whole body.Their research indicated a significant difference between the metabolic profiles of the two groups.
Dr. Arredouani said that interestingly, the difference between the two groups studied seems to be due mainly to differences in the use of fatty acids.The results suggest that low levels of salivary alpha-amylase somehow reduces the uptake of glucose, the primary source of energy for the cells, and therefore the body shifts towards fatty acids usage to derive energy.
“If confirmed in bigger studies, the outcome may have clinical importance.Thus, low salivary amylase individuals who chronically ingest starch, in the form of rice for example, as is the case in the Middle East region, should eventually be considered to be at-risk of developing metabolic disorders, and therefore preventive nutritional and behavioral counseling should be provided to them.”
Dr. Omar El Agnaf, acting executive director of QBRI, added: “This QBRI-supported study furthers our aim to take an integrative and multidisciplinary approach in providing crucial insights into a key healthcare concerns in Qatar. By participating in collaborative studies like this one, we hope to continue to advance knowledge and champion the cause of fostering innovation in research.”
Brown University biochip may lead to saliva glucose detector
Brown University researchers have created an experimental biochip that may one day test for miniscule levels of glucose in saliva rather than requiring diabetics to suffer repeated and painful finger pricks, lead scientist Domenico Pacifici told Mass High Tech in an interview.
The researchers used a technique called plasmonic interferometry — a convergence of nanotechnology and surface plasmonics, which explores the interaction of electrons and photons (light). Pacifici, an assistant professor in Brown’s School of Engineering in Providence, R.I., said the experimental device holds promise for other types of tests. He said surgeons already have expressed interest in the technology to check levels of cytokines, which are small cell-signaling molecules released when someone suffers an injury. By monitoring cytokine levels on a battlefield, for example, surgeons can determine the best time to operate on a patient with multiple injuries, he said.
“It could be possible to use these biochips to carry out the screening of multiple biomarkers for individual patients, all at once and in parallel, with unprecedented sensitivity,” Pacifici said. The results of the research, which resulted in a proof-of-concept biochip, were published in a recent issue of Nano Letters.
Each plasmonic interferometer — there are thousands of them per square millimeter — consists of a slit flanked by two grooves etched in a silver metal film. Changes in light intensity transmitted through the slit of each plasmonic interferometer provide information about the glucose concentration.
Some 26 million Americans have diabetes and typically check their glucose level by drawing blood, often with a pin prick to the finger tip, he said. “Finger pricks are not convenient, and compliance is a problem, especially in little kids,” Pacifici said. “Our test would be something that you put in your mouth for a few seconds, and then insert into a test machine to read it.”
A challenge for Pacifici and his fellow researchers is that glucose in human saliva is typically about 100 times less concentrated than in the blood. That is why they turned to plasmonic interferometers, which can pick up on such small concentrations.
“This is a proof of concept that plasmonic interferometers can be used to detect molecules in low concentrations, using a footprint that is 10 times smaller than a human hair,” he said. The technique could be used to detect other chemicals or substances, from anthrax to biological compounds at the same time on the same chip, he added.
To create the sensor, the researchers carved a slit about 100 nanometers wide and etched two 200 nanometer-wide grooves on either side of it. The slit captures incoming photons and confines them. The grooves scatter the incoming photons, which interact with the free electrons on the sensor’s metal surface. Those free electron-photon interactions create surface plasmon polaritons, special waves that move along the sensor’s surface until they meet the photons in the slit, like two ocean waves coming from different directions and colliding with each other. This wave interference determines the light intensity transmitted through the slit. The presence of the chemical measured on the sensor’s surface generates a change in the relative phase difference between the two surface plasmon waves, which in turn causes a change in light intensity.
The National Science Foundation and Brown funded the research. Pacifici said he is looking for more funding externally to move the project along more quickly. That could include a spinout company. Brown has filed a provisional patent on the technology.
Pacifici said he expects to develop a prototype in the next two years, and within five years to start testing the device. He and his co-workers are now building a database of the different components of saliva that will help them hone the current biochip for detecting glucose. Saliva contains about 99 percent water, but the remaining 1 percent includes various cells and glucose, so the biochip needs to be made more specific.
The researchers used a technique called plasmonic interferometry — a convergence of nanotechnology and surface plasmonics, which explores the interaction of electrons and photons (light). Pacifici, an assistant professor in Brown’s School of Engineering in Providence, R.I., said the experimental device holds promise for other types of tests. He said surgeons already have expressed interest in the technology to check levels of cytokines, which are small cell-signaling molecules released when someone suffers an injury. By monitoring cytokine levels on a battlefield, for example, surgeons can determine the best time to operate on a patient with multiple injuries, he said.
“It could be possible to use these biochips to carry out the screening of multiple biomarkers for individual patients, all at once and in parallel, with unprecedented sensitivity,” Pacifici said. The results of the research, which resulted in a proof-of-concept biochip, were published in a recent issue of Nano Letters.
Each plasmonic interferometer — there are thousands of them per square millimeter — consists of a slit flanked by two grooves etched in a silver metal film. Changes in light intensity transmitted through the slit of each plasmonic interferometer provide information about the glucose concentration.
Some 26 million Americans have diabetes and typically check their glucose level by drawing blood, often with a pin prick to the finger tip, he said. “Finger pricks are not convenient, and compliance is a problem, especially in little kids,” Pacifici said. “Our test would be something that you put in your mouth for a few seconds, and then insert into a test machine to read it.”
A challenge for Pacifici and his fellow researchers is that glucose in human saliva is typically about 100 times less concentrated than in the blood. That is why they turned to plasmonic interferometers, which can pick up on such small concentrations.
“This is a proof of concept that plasmonic interferometers can be used to detect molecules in low concentrations, using a footprint that is 10 times smaller than a human hair,” he said. The technique could be used to detect other chemicals or substances, from anthrax to biological compounds at the same time on the same chip, he added.
To create the sensor, the researchers carved a slit about 100 nanometers wide and etched two 200 nanometer-wide grooves on either side of it. The slit captures incoming photons and confines them. The grooves scatter the incoming photons, which interact with the free electrons on the sensor’s metal surface. Those free electron-photon interactions create surface plasmon polaritons, special waves that move along the sensor’s surface until they meet the photons in the slit, like two ocean waves coming from different directions and colliding with each other. This wave interference determines the light intensity transmitted through the slit. The presence of the chemical measured on the sensor’s surface generates a change in the relative phase difference between the two surface plasmon waves, which in turn causes a change in light intensity.
The National Science Foundation and Brown funded the research. Pacifici said he is looking for more funding externally to move the project along more quickly. That could include a spinout company. Brown has filed a provisional patent on the technology.
Pacifici said he expects to develop a prototype in the next two years, and within five years to start testing the device. He and his co-workers are now building a database of the different components of saliva that will help them hone the current biochip for detecting glucose. Saliva contains about 99 percent water, but the remaining 1 percent includes various cells and glucose, so the biochip needs to be made more specific.
Effect of Infancy-onset Dietary Intervention on Salivary Cholesterol of Children: a Randomized Controlled Trial
Abstract
This study investigated salivary cholesterol of children from 6 to 16 years of age in response to dietary intervention. One thousand sixty-two infants started in the prospective, randomized project. At 3 years of age, every fifth child was invited into the study (n = 178). Of these, 148 enrolled, and 86 completed the oral sub-study at 16 years of age. The intervention aimed at restricting the child’s saturated fat and cholesterol intake. Control children received no special recommendations. Every third year, paraffin-stimulated saliva samples (10.0 mL) were collected for cholesterol assays. Nutrient intakes and serum total cholesterol concentrations were regularly followed up by means of 4-day food records and blood samples. Intake of saturated fatty acids (SAFA) was lower in the intervention than in the control group (p < 0.001). Salivary cholesterol concentration increased from 1.9 (± 1.1) μmol/L at 6 years of age to 16.0 (± 9.0) μmol/L at 16 years of age. The increase was smaller in the intervention than in the control group (p < 0.001). The ratios of salivary to serum cholesterol concentrations tended to be higher in boys than in girls (p = 0.07). Thus, dietary intervention was reflected in children’s salivary cholesterol values more sensitively than in serum cholesterol values. (clinicaltrials.gov NCT00223600).
This study investigated salivary cholesterol of children from 6 to 16 years of age in response to dietary intervention. One thousand sixty-two infants started in the prospective, randomized project. At 3 years of age, every fifth child was invited into the study (n = 178). Of these, 148 enrolled, and 86 completed the oral sub-study at 16 years of age. The intervention aimed at restricting the child’s saturated fat and cholesterol intake. Control children received no special recommendations. Every third year, paraffin-stimulated saliva samples (10.0 mL) were collected for cholesterol assays. Nutrient intakes and serum total cholesterol concentrations were regularly followed up by means of 4-day food records and blood samples. Intake of saturated fatty acids (SAFA) was lower in the intervention than in the control group (p < 0.001). Salivary cholesterol concentration increased from 1.9 (± 1.1) μmol/L at 6 years of age to 16.0 (± 9.0) μmol/L at 16 years of age. The increase was smaller in the intervention than in the control group (p < 0.001). The ratios of salivary to serum cholesterol concentrations tended to be higher in boys than in girls (p = 0.07). Thus, dietary intervention was reflected in children’s salivary cholesterol values more sensitively than in serum cholesterol values. (clinicaltrials.gov NCT00223600).
The Science Behind Why We Love Ice Cream
Why people prefer certain foods over others depends largely on a combination of taste and texture. While taste sensations are fairly well understood, scientists are just beginning to unravel the mystery of food texture.
Now, researchers at the Monell Chemical Senses Center in Philadelphia have found that an enzyme in saliva called amylase, which breaks down starch into liquid, could play a key role in determining the appeal of various textures of food. A new genetic study shows that people produce strikingly different amounts of amylase, and that the more of the enzyme people have in their mouth the faster they can liquefy starchy foods.
Scientists think this finding could help explain why people experience foods as creamy or slimy, sticky or watery, and that this perception could affect our preference for foods. For the numerous foods that contain starch, including pudding, sauces and even maple syrup, what can feel just right to some people is experienced as too runny or not melting enough for others because they produce different amounts of the enzyme.
The ability to quickly break down starch, which is a type of carbohydrate, is only one part of the puzzle that determines what people like to eat. Taste preferences are driven by a complicated interaction between taste buds and other receptors in the mouth and nose, and the messages they send to the brain. Culture plays a role, as people tend to like foods that are familiar, says Rick Mattes, a foods and nutrition professor at Purdue University in West Lafayette, Ind. And repetition sometimes can win out: Many people initially don't like oysters because of their slimy texture, for instance, but can come to enjoy them after several tries.
"We all have had the experience of liking a food that someone else complains is too tacky, or slippery, or gritty, or pulpy," says Paul Breslin, a researcher at the Monell center and a professor at Rutgers University in New Brunswick, N.J. "This is why a given line of product often comes in different textural forms," such as orange juice with and without pulp, he says.
Starch comprises or is added to about 60% of the foods people typically eat, so determining how it is digested is key to understanding food-texture preferences, Monell center scientists say. Other research has shown that people have a preference for creamy sensations as well as for foods that start off solid and melt in the mouth such as ice cream and chocolate, says Dr. Breslin, who began the current research because of his interest in creaminess. Amylase also could help explain individual preferences for different brands of ice cream or yogurt, for instance, because they contain different amounts of added starch.
In their recent work, Monell researchers had 73 adults swirl around in their mouths solutions made up of different concentrations of starch—blobs of translucent gelatinous substances with no particular taste—and rate their runniness over the course of 60 seconds. Depending on the amount of amylase individuals produced, the starch could be reduced to liquid within seconds.
The researchers also took DNA samples of the participants from a blood sample or cheek swab and studied the link between the numbers of copies of a gene that turns on the production of amylase and how quickly the participant reported the sample turned runny. The findings showed that the number of copies of the gene, called AMY1, varied widely between individuals. People with higher numbers of gene copies reported that the starch turned to liquid more quickly. The study was published last month in PLoS ONE, a journal of the Public Library of Science.
The Monell researchers are now investigating whether people with more AMY1 copies see larger spikes in blood glucose after eating. They also plan to study the link between greater amylase production and food preferences, hypothesizing that people who make more of the enzyme will prefer starchy products because they get a faster blast of glucose into their bloodstream.
The role of amylase and the rate of starch breakdown also has implications for diabetes. People who digest starch quickly could be more likely to have larger spikes in blood-sugar levels and thus a need for the body to generate more insulin. This continued demand on the body might lead these people to become insulin resistant or even diabetic if the body's ability to produce insulin breaks down, says Abigail Mandel, Dr. Breslin's colleague at Monell and first author on the study.
Amylase and other enzymes in saliva could also help explain food-texture preferences that are known to vary with age, Dr. Breslin says. For instance, many young children dislike certain fruits because of a perceived sliminess—think of the inside of a tomato. But people's saliva-flow rate tends to slow with age, which might affect their ability to break down starch in the mouth and reduce sensations of sliminess.
Another factor in food preferences: People vary—probably based on genetics—in their ability to detect other textures, such as fat, and bitter and sweet tastes. Valerie Duffy, a registered dietitian and professor in the department of allied health science at the University of Connecticut, Storrs, Conn., has shown in her research that adults with a gene that makes bitter tastes more intense consume fewer vegetables containing bitter compounds, such as kale or spinach.
But that genetic preference can be changed by repeatedly exposing the individual to the taste or by masking the bitterness, even at an early age, she has found. In a preliminary study with preschoolers, Dr. Duffy's group added a sweet taste to balance out the bitterness of certain vegetables—less than half a teaspoon of sugar to a cup of broccoli or asparagus, for example, during cooking—and found that the children were more accepting of the greens. Even when the sweetness was removed, the children still liked the vegetables more than before because they had developed a positive association with them, she says. "It suggests that people should focus on what they like to eat and make it work for them," Dr. Duffy says.
Now, researchers at the Monell Chemical Senses Center in Philadelphia have found that an enzyme in saliva called amylase, which breaks down starch into liquid, could play a key role in determining the appeal of various textures of food. A new genetic study shows that people produce strikingly different amounts of amylase, and that the more of the enzyme people have in their mouth the faster they can liquefy starchy foods.
Scientists think this finding could help explain why people experience foods as creamy or slimy, sticky or watery, and that this perception could affect our preference for foods. For the numerous foods that contain starch, including pudding, sauces and even maple syrup, what can feel just right to some people is experienced as too runny or not melting enough for others because they produce different amounts of the enzyme.
The ability to quickly break down starch, which is a type of carbohydrate, is only one part of the puzzle that determines what people like to eat. Taste preferences are driven by a complicated interaction between taste buds and other receptors in the mouth and nose, and the messages they send to the brain. Culture plays a role, as people tend to like foods that are familiar, says Rick Mattes, a foods and nutrition professor at Purdue University in West Lafayette, Ind. And repetition sometimes can win out: Many people initially don't like oysters because of their slimy texture, for instance, but can come to enjoy them after several tries.
"We all have had the experience of liking a food that someone else complains is too tacky, or slippery, or gritty, or pulpy," says Paul Breslin, a researcher at the Monell center and a professor at Rutgers University in New Brunswick, N.J. "This is why a given line of product often comes in different textural forms," such as orange juice with and without pulp, he says.
Starch comprises or is added to about 60% of the foods people typically eat, so determining how it is digested is key to understanding food-texture preferences, Monell center scientists say. Other research has shown that people have a preference for creamy sensations as well as for foods that start off solid and melt in the mouth such as ice cream and chocolate, says Dr. Breslin, who began the current research because of his interest in creaminess. Amylase also could help explain individual preferences for different brands of ice cream or yogurt, for instance, because they contain different amounts of added starch.
In their recent work, Monell researchers had 73 adults swirl around in their mouths solutions made up of different concentrations of starch—blobs of translucent gelatinous substances with no particular taste—and rate their runniness over the course of 60 seconds. Depending on the amount of amylase individuals produced, the starch could be reduced to liquid within seconds.
The researchers also took DNA samples of the participants from a blood sample or cheek swab and studied the link between the numbers of copies of a gene that turns on the production of amylase and how quickly the participant reported the sample turned runny. The findings showed that the number of copies of the gene, called AMY1, varied widely between individuals. People with higher numbers of gene copies reported that the starch turned to liquid more quickly. The study was published last month in PLoS ONE, a journal of the Public Library of Science.
The Monell researchers are now investigating whether people with more AMY1 copies see larger spikes in blood glucose after eating. They also plan to study the link between greater amylase production and food preferences, hypothesizing that people who make more of the enzyme will prefer starchy products because they get a faster blast of glucose into their bloodstream.
The role of amylase and the rate of starch breakdown also has implications for diabetes. People who digest starch quickly could be more likely to have larger spikes in blood-sugar levels and thus a need for the body to generate more insulin. This continued demand on the body might lead these people to become insulin resistant or even diabetic if the body's ability to produce insulin breaks down, says Abigail Mandel, Dr. Breslin's colleague at Monell and first author on the study.
Amylase and other enzymes in saliva could also help explain food-texture preferences that are known to vary with age, Dr. Breslin says. For instance, many young children dislike certain fruits because of a perceived sliminess—think of the inside of a tomato. But people's saliva-flow rate tends to slow with age, which might affect their ability to break down starch in the mouth and reduce sensations of sliminess.
Another factor in food preferences: People vary—probably based on genetics—in their ability to detect other textures, such as fat, and bitter and sweet tastes. Valerie Duffy, a registered dietitian and professor in the department of allied health science at the University of Connecticut, Storrs, Conn., has shown in her research that adults with a gene that makes bitter tastes more intense consume fewer vegetables containing bitter compounds, such as kale or spinach.
But that genetic preference can be changed by repeatedly exposing the individual to the taste or by masking the bitterness, even at an early age, she has found. In a preliminary study with preschoolers, Dr. Duffy's group added a sweet taste to balance out the bitterness of certain vegetables—less than half a teaspoon of sugar to a cup of broccoli or asparagus, for example, during cooking—and found that the children were more accepting of the greens. Even when the sweetness was removed, the children still liked the vegetables more than before because they had developed a positive association with them, she says. "It suggests that people should focus on what they like to eat and make it work for them," Dr. Duffy says.
Comparative Human Salivary and Plasma Proteomes.
Abstract
The protein compositions, or the proteomes, found in human salivary and plasma fluids are compared. From recent experimental work by many laboratories, a catalogue of 2290 proteins found in whole saliva has been compiled. This list of salivary proteins is compared with the 2698 proteins found in plasma. Approximately 27% of the whole-saliva proteins are found in plasma. However, despite this apparent low degree of overlap, the distribution found across Gene Ontological categories, such as molecular function, biological processes, and cellular components, shows significant similarities.
Moreover, nearly 40% of the proteins that have been suggested to be candidate markers for diseases such as cancer, cardiovascular disease, and stroke can be found in whole saliva. These comparisons and correlations should encourage researchers to consider the use of saliva to discover new protein markers of disease and as a diagnostic non-proximal fluid to detect early signs of disease throughout the body.
Loo JA, Yan W, Ramachandran P, Wong DT.
The protein compositions, or the proteomes, found in human salivary and plasma fluids are compared. From recent experimental work by many laboratories, a catalogue of 2290 proteins found in whole saliva has been compiled. This list of salivary proteins is compared with the 2698 proteins found in plasma. Approximately 27% of the whole-saliva proteins are found in plasma. However, despite this apparent low degree of overlap, the distribution found across Gene Ontological categories, such as molecular function, biological processes, and cellular components, shows significant similarities.
Moreover, nearly 40% of the proteins that have been suggested to be candidate markers for diseases such as cancer, cardiovascular disease, and stroke can be found in whole saliva. These comparisons and correlations should encourage researchers to consider the use of saliva to discover new protein markers of disease and as a diagnostic non-proximal fluid to detect early signs of disease throughout the body.
Loo JA, Yan W, Ramachandran P, Wong DT.
Salivary testosterone, cortisol, and progesterone: Two-week stability, interhormone correlations, and effects of time of day, menstrual cycle, and ora
Abstract
With salivary assessment of steroid hormones increasing, more work is needed to address fundamental properties of steroid hormone levels in humans. Using a test–retest design and radioimmunoassay assessment of salivary steroids, we tested the reliability of testosterone, cortisol, and progesterone levels across two weeks, as well as the effects of oral contraceptives, menstrual cycle phase, and time of day on steroid hormone levels.
Testosterone and cortisol were found to be highly reliable in both sexes. Progesterone was found to be reliable after collapsing across sex. Oral contraceptive use was associated with lower levels of testosterone, but did not affect cortisol.
Contrary to expectations, oral contraceptives also did not affect progesterone. Menstrual cycle was found to affect levels of progesterone, but not testosterone or cortisol. Time of day had an effect on cortisol, on progesterone only at one testing time, and no effect on testosterone. We explored the interhormone correlations among testosterone, progesterone, and cortisol. All three hormones were positively correlated with one another in men. In women, progesterone was positively correlated with testosterone and cortisol, but testosterone and cortisol were uncorrelated.
Scott H. Lieninga, , , Steven J. Stantonb, Ekjyot K. Sainic and Oliver C. Schultheissd
a Department of Psychology, University of Texas at Austin, 1 University Station A8000, Austin, TX 78705, USA
b Duke University, USA
c University of Michigan, Ann Arbor, USA
d Friedrich-Alexander University, Erlangen, Germany
With salivary assessment of steroid hormones increasing, more work is needed to address fundamental properties of steroid hormone levels in humans. Using a test–retest design and radioimmunoassay assessment of salivary steroids, we tested the reliability of testosterone, cortisol, and progesterone levels across two weeks, as well as the effects of oral contraceptives, menstrual cycle phase, and time of day on steroid hormone levels.
Testosterone and cortisol were found to be highly reliable in both sexes. Progesterone was found to be reliable after collapsing across sex. Oral contraceptive use was associated with lower levels of testosterone, but did not affect cortisol.
Contrary to expectations, oral contraceptives also did not affect progesterone. Menstrual cycle was found to affect levels of progesterone, but not testosterone or cortisol. Time of day had an effect on cortisol, on progesterone only at one testing time, and no effect on testosterone. We explored the interhormone correlations among testosterone, progesterone, and cortisol. All three hormones were positively correlated with one another in men. In women, progesterone was positively correlated with testosterone and cortisol, but testosterone and cortisol were uncorrelated.
Scott H. Lieninga, , , Steven J. Stantonb, Ekjyot K. Sainic and Oliver C. Schultheissd
a Department of Psychology, University of Texas at Austin, 1 University Station A8000, Austin, TX 78705, USA
b Duke University, USA
c University of Michigan, Ann Arbor, USA
d Friedrich-Alexander University, Erlangen, Germany
Systematic comparison of the human saliva and plasma proteomes.
Proteomics Clin Appl. 2009 Jan 1;3(1):116-134.
The proteome of human salivary fluid has the potential to open new doors for disease biomarker discovery. A recent study to comprehensively identify and catalog the human ductal salivary proteome led to the compilation of 1166 proteins. The protein complexity of both saliva and plasma is large, suggesting that a comparison of these two proteomes will provide valuable insight into their physiological significance and an understanding of the unique and overlapping disease diagnostic potential that each fluid provides.
To create a more comprehensive catalog of human salivary proteins, we have first compiled an extensive list of proteins from whole saliva (WS) identified through MS experiments. The WS list is thereafter combined with the proteins identified from the ductal parotid, and submandibular and sublingual (parotid/SMSL) salivas. In parallel, a core dataset of the human plasma proteome with 3020 protein identifications was recently released.
A total of 1939 nonredundant salivary proteins were compiled from a total of 19 474 unique peptide sequences identified from whole and ductal salivas; 740 out of the total 1939 salivary proteins were identified in both whole and ductal saliva. A total of 597 of the salivary proteins have been observed in plasma. Gene ontology (GO) analysis showed similarities in the distributions of the saliva and plasma proteomes with regard to cellular localization, biological processes, and molecular function, but revealed differences which may be related to the different physiological functions of saliva and plasma.
The comprehensive catalog of the salivary proteome and its comparison to the plasma proteome provides insights useful for future study, such as exploration of potential biomarkers for disease diagnostics.
The proteome of human salivary fluid has the potential to open new doors for disease biomarker discovery. A recent study to comprehensively identify and catalog the human ductal salivary proteome led to the compilation of 1166 proteins. The protein complexity of both saliva and plasma is large, suggesting that a comparison of these two proteomes will provide valuable insight into their physiological significance and an understanding of the unique and overlapping disease diagnostic potential that each fluid provides.
To create a more comprehensive catalog of human salivary proteins, we have first compiled an extensive list of proteins from whole saliva (WS) identified through MS experiments. The WS list is thereafter combined with the proteins identified from the ductal parotid, and submandibular and sublingual (parotid/SMSL) salivas. In parallel, a core dataset of the human plasma proteome with 3020 protein identifications was recently released.
A total of 1939 nonredundant salivary proteins were compiled from a total of 19 474 unique peptide sequences identified from whole and ductal salivas; 740 out of the total 1939 salivary proteins were identified in both whole and ductal saliva. A total of 597 of the salivary proteins have been observed in plasma. Gene ontology (GO) analysis showed similarities in the distributions of the saliva and plasma proteomes with regard to cellular localization, biological processes, and molecular function, but revealed differences which may be related to the different physiological functions of saliva and plasma.
The comprehensive catalog of the salivary proteome and its comparison to the plasma proteome provides insights useful for future study, such as exploration of potential biomarkers for disease diagnostics.
Human papillomavirus in saliva of patients with oral squamous cell carcinoma
Objective: The aim of this study was to evaluate the presence of human papillomavirus (HPV) in saliva rinses of patients with oral squamous cell carcinoma and to analyze the possibility of using saliva as a diagnostic method for screening high-risk patients.
Study design: The saliva sample of 22 patients with oral squamous cell carcinoma and 20 age-sex matched healthy controls were obtained. The presence of HPV 6, 11, 16, 18, 31, and 33 was evaluated by polymerase chain reaction (PCR).
Results: In 40.9% of the patients and in 25% of the controls, the saliva was shown to be positive for HPV. In 27.3% of the patients and in 20% of the controls, the saliva was shown to be positive for HPV16; and none of the controls, except one patient was shown to be positive for HPV 18. Neither patients nor controls were positive for HPV 31 and 33. These differences were not statistically significant.
Conclusions: The results of this study were unable to support the detection of HPV in saliva rinses as a diagnostic method for OSCC.
Sahebjamee M, Boorghani M, Ghaffari SR, Atarbashimoghadam F, Keyhani A.
Department of Oral Medicine, Faculty of Dentistry, Tehran University of Medical Science, Tehran-Iran
Study design: The saliva sample of 22 patients with oral squamous cell carcinoma and 20 age-sex matched healthy controls were obtained. The presence of HPV 6, 11, 16, 18, 31, and 33 was evaluated by polymerase chain reaction (PCR).
Results: In 40.9% of the patients and in 25% of the controls, the saliva was shown to be positive for HPV. In 27.3% of the patients and in 20% of the controls, the saliva was shown to be positive for HPV16; and none of the controls, except one patient was shown to be positive for HPV 18. Neither patients nor controls were positive for HPV 31 and 33. These differences were not statistically significant.
Conclusions: The results of this study were unable to support the detection of HPV in saliva rinses as a diagnostic method for OSCC.
Sahebjamee M, Boorghani M, Ghaffari SR, Atarbashimoghadam F, Keyhani A.
Department of Oral Medicine, Faculty of Dentistry, Tehran University of Medical Science, Tehran-Iran
Salivary alpha-amylase as a longitudinal predictor of children's externalizing symptoms:
Department of Psychology, University of Kentucky, KY 40506, United States.
Salivary alpha-amylase (sAA) was examined as a predictor of children's externalizing symptoms cross-sectionally when children were in the 3rd grade (T1; N=64) and again in the 5th grade (T2; N=54) and longitudinally over two years. Parasympathetic nervous system (PNS) activity, indexed by respiratory sinus arrhythmia (RSA), was examined as a moderator of the sAA and child externalizing link. Participants were healthy, typically developing children, 34% of whom were African American and the rest European American. At each time point, saliva samples were collected during afternoon laboratory visits and assayed for sAA. Children's RSA was measured during baseline conditions and in response to an inter-adult argument and a star-tracing task. Cross-sectional associations between sAA and externalizing symptoms at T1 and T2 were moderated by PNS functioning. Longitudinally, sAA was directly associated with changes in externalizing symptoms in a non-linear fashion. Specifically, lower externalizing symptoms were predicted for children with moderate levels of sAA, but higher externalizing was predicted for children with higher or lower levels of sAA. Findings highlight the importance of the contemporaneous assessment of SNS and PNS functioning in the prediction of child psychopathology, and the need to examine curvilinear relations between ANS functioning and behavior
Salivary alpha-amylase (sAA) was examined as a predictor of children's externalizing symptoms cross-sectionally when children were in the 3rd grade (T1; N=64) and again in the 5th grade (T2; N=54) and longitudinally over two years. Parasympathetic nervous system (PNS) activity, indexed by respiratory sinus arrhythmia (RSA), was examined as a moderator of the sAA and child externalizing link. Participants were healthy, typically developing children, 34% of whom were African American and the rest European American. At each time point, saliva samples were collected during afternoon laboratory visits and assayed for sAA. Children's RSA was measured during baseline conditions and in response to an inter-adult argument and a star-tracing task. Cross-sectional associations between sAA and externalizing symptoms at T1 and T2 were moderated by PNS functioning. Longitudinally, sAA was directly associated with changes in externalizing symptoms in a non-linear fashion. Specifically, lower externalizing symptoms were predicted for children with moderate levels of sAA, but higher externalizing was predicted for children with higher or lower levels of sAA. Findings highlight the importance of the contemporaneous assessment of SNS and PNS functioning in the prediction of child psychopathology, and the need to examine curvilinear relations between ANS functioning and behavior
Salivary alpha-amylase, cortisol and chromogranin A responses to a lecture: impact of sex.
The aim of this study was to (1) examine the presence of stress on professors when they teach in front of 200 students and analyse objectively such stress using biomarkers such as salivary cortisol, chromogranin A (CgA) and alpha-amylase (AA) (2) investigate whether sex affects the reactivity of salivary alpha-amylase (sAA) and cortisol concentrations and the interaction of both hormonal systems. Fifty-two participants (26 women and 26 men) collected nine unstimulated saliva samples on 2 days, (one working day, and one resting day).
Cortisol concentrations and AA activity measured on the teaching day were significantly higher than those noted on the resting values. No differences between the resting day and the teaching day were reported for CgA. Our results showed a cortisol response to teaching, which was characterized by an anticipatory rise. The alpha-amylase level was significantly increased after the end of the lecture, and returned to the pre-lecture level 30 min after the end of the lecture.
The awakening cortisol response noted on the teaching day was significantly higher in females than in males. No baseline sex differences in sAA and CgA were observed and men and women seem to have a comparable reactivity in salivary alpha-amylase , CgA and cortisol levels on lecture stress. The mechanisms that leads to modify activity of salivary alpha-amylase and CgA due to stress is not entirely understood and further research is needed to elucidate them.
Laboratoire AMAPP, UFRSTAPS-2, Allée du Château, Orléans Cedex, France.
Cortisol concentrations and AA activity measured on the teaching day were significantly higher than those noted on the resting values. No differences between the resting day and the teaching day were reported for CgA. Our results showed a cortisol response to teaching, which was characterized by an anticipatory rise. The alpha-amylase level was significantly increased after the end of the lecture, and returned to the pre-lecture level 30 min after the end of the lecture.
The awakening cortisol response noted on the teaching day was significantly higher in females than in males. No baseline sex differences in sAA and CgA were observed and men and women seem to have a comparable reactivity in salivary alpha-amylase , CgA and cortisol levels on lecture stress. The mechanisms that leads to modify activity of salivary alpha-amylase and CgA due to stress is not entirely understood and further research is needed to elucidate them.
Laboratoire AMAPP, UFRSTAPS-2, Allée du Château, Orléans Cedex, France.
Salivary Proteomics for Oral Cancer Biomarker Discovery
Purpose: This study aims to explore the presence of informative protein biomarkers in the human saliva proteome and to evaluate their potential for detection of oral squamous cell carcinoma (OSCC).
Experimental Design: Whole saliva samples were collected from patients (n = 64) with OSCC and matched healthy subjects (n = 64). The proteins in pooled whole saliva samples of patients with OSCC (n = 16) and matched healthy subjects (n = 16) were profiled using shotgun proteomics based on C4 reversed-phase liquid chromatography for prefractionation, capillary reversed-phase liquid chromatography with quadruple time-of-flight mass spectrometry, and Mascot sequence database searching. Immunoassays were used for validation of the candidate biomarkers on a new group of OSCC (n = 48) and matched healthy subjects (n = 48). Receiver operating characteristic analysis was exploited to evaluate the diagnostic value of discovered candidate biomarkers for OSCC.
Results: Subtractive proteomics revealed several salivary proteins at differential levels between the OSCC patients and matched control subjects. Five candidate biomarkers were successfully validated using immunoassays on an independent set of OSCC patients and matched healthy subjects. The combination of these candidate biomarkers yielded a receiver operating characteristic value of 93%, sensitivity of 90%, and specificity of 83% in detecting OSCC.
Conclusion: Patient-based saliva proteomics is a promising approach to searching for OSCC biomarkers . The discovery of these new targets may lead to a simple clinical tool for the noninvasive diagnosis of oral cancer . Long-term longitudinal studies with large populations of individuals with oral cancer and those who are at high risk of developing oral cancer are needed to validate these potential biomarkers.
Shen Hu1, Martha Arellano1, Pinmanee Boontheung2, Jianghua Wang1, Hui Zhou1, Jiang Jiang1, David Elashoff7, Roger Wei1, Joseph A. Loo2,3,4 and David T. Wong1,3,5,6
Authors' Affiliations: 1 Oral Biology and Medicine Division and Dental Research Institute, School of Dentistry, 2 Department of Chemistry and Biochemistry, 3 Jonsson Comprehensive Cancer Center, 4 Department of Biological Chemistry, David Geffen School of Medicine, 5 Division of Head and Neck Surgery/Otolaryngology, School of Medicine, 6 Henry Samueli School of Engineering and Applied Science, and 7 Department of Biostatistics, School of Public Health, University of California at Los Angeles, Los Angeles, California
Experimental Design: Whole saliva samples were collected from patients (n = 64) with OSCC and matched healthy subjects (n = 64). The proteins in pooled whole saliva samples of patients with OSCC (n = 16) and matched healthy subjects (n = 16) were profiled using shotgun proteomics based on C4 reversed-phase liquid chromatography for prefractionation, capillary reversed-phase liquid chromatography with quadruple time-of-flight mass spectrometry, and Mascot sequence database searching. Immunoassays were used for validation of the candidate biomarkers on a new group of OSCC (n = 48) and matched healthy subjects (n = 48). Receiver operating characteristic analysis was exploited to evaluate the diagnostic value of discovered candidate biomarkers for OSCC.
Results: Subtractive proteomics revealed several salivary proteins at differential levels between the OSCC patients and matched control subjects. Five candidate biomarkers were successfully validated using immunoassays on an independent set of OSCC patients and matched healthy subjects. The combination of these candidate biomarkers yielded a receiver operating characteristic value of 93%, sensitivity of 90%, and specificity of 83% in detecting OSCC.
Conclusion: Patient-based saliva proteomics is a promising approach to searching for OSCC biomarkers . The discovery of these new targets may lead to a simple clinical tool for the noninvasive diagnosis of oral cancer . Long-term longitudinal studies with large populations of individuals with oral cancer and those who are at high risk of developing oral cancer are needed to validate these potential biomarkers.
Shen Hu1, Martha Arellano1, Pinmanee Boontheung2, Jianghua Wang1, Hui Zhou1, Jiang Jiang1, David Elashoff7, Roger Wei1, Joseph A. Loo2,3,4 and David T. Wong1,3,5,6
Authors' Affiliations: 1 Oral Biology and Medicine Division and Dental Research Institute, School of Dentistry, 2 Department of Chemistry and Biochemistry, 3 Jonsson Comprehensive Cancer Center, 4 Department of Biological Chemistry, David Geffen School of Medicine, 5 Division of Head and Neck Surgery/Otolaryngology, School of Medicine, 6 Henry Samueli School of Engineering and Applied Science, and 7 Department of Biostatistics, School of Public Health, University of California at Los Angeles, Los Angeles, California
Salivary alpha amylase and cortisol responses to different stress tasks: Impact of sex
Neuro-endocrine markers such as salivary alpha amylase (sAA) and cortisol (CORT) play an important role in establishing human responses to stressful events. Whereas sAA levels reflect sympathetic system activity, salivary cortisol appears to be a valid measure for HPA axis activity. Although many studies looked at either sAA or CORT responses in reaction to stress, work still has to be done to look at the way these systems interact, especially when both systems are activated. Additionally, sex effects in CORT responses have been investigated relatively often, but possible sex differences in sAA levels and responses, or the way both systems interact has not been the focus of sufficient studies to yield a univocal conclusion.
In this study we presented a group of healthy participants (n = 80) with two mildly stressful tasks, consisting of an aversive picture rating task and a cold pressor stress (CPS) task. The second task was compared with a control task. We expected a rise in sAA level in response to the first task and sAA as well as CORT responses on the second task and explored the interaction between the two responses.
Results indicate that salivary alpha amylase (sAA) is indeed a sensitive marker in both psychologically and physically induced arousal paradigms, whereas a cortisol response was only observed in the CPS task. Men had higher sAA levels than women during the complete course of the study, but men and women were comparable in their responsivity to the tasks. No strong correlations between sAA and CORT responses were found.
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In this study we presented a group of healthy participants (n = 80) with two mildly stressful tasks, consisting of an aversive picture rating task and a cold pressor stress (CPS) task. The second task was compared with a control task. We expected a rise in sAA level in response to the first task and sAA as well as CORT responses on the second task and explored the interaction between the two responses.
Results indicate that salivary alpha amylase (sAA) is indeed a sensitive marker in both psychologically and physically induced arousal paradigms, whereas a cortisol response was only observed in the CPS task. Men had higher sAA levels than women during the complete course of the study, but men and women were comparable in their responsivity to the tasks. No strong correlations between sAA and CORT responses were found.
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Human spit contains 1,116 unique proteins
U.S. researchers have identified all 1,116 unique proteins found in human saliva glands, a discovery they said on Tuesday could usher in a wave of convenient, spit-based diagnostic tests that could be done without the need for a single drop of blood.
Natural-born painkiller found in human saliva
Saliva from humans has yielded a natural painkiller up to six times more powerful than morphine, researchers say.
The substance, dubbed opiorphin, may spawn a new generation of natural painkillers that relieve pain as well as morphine but without the addictive and psychological side effects of the traditional drug.
When the researchers injected a pain-inducing chemical into rats’ paws, 1 milligram of opiorphin per kilogram of body weight achieved the same painkilling effect as 3 milligrams of morphine.
The substance was so successful at blocking pain that, in a test involving a platform of upended pins, the rats needed six times as much morphine as opiorphin to render them oblivious to the pain of standing on the needle points.
Anti-depressive angle
“Its pain-suppressive effect is like that of morphine,” says Catherine Rougeot at the Pasteur Institute in Paris, France, who led the research. “But we have to test its side effects as it is not a pure painkiller,” she says. “It may also be an anti-depressive molecule.”
Rougeot and colleagues discovered that opiorphin works in nerve cells of the spine by stopping the usual destruction of natural pain-killing opiates there, called enkephalins.
Opiorphin is such a simple molecule that it should be possible to synthesise it and produce large quantities without having to isolate it from saliva, Rougeot explains. Alternatively, it might be possible to find drugs which trigger patients’ bodies to produce more of the molecule themselves.
The substance, dubbed opiorphin, may spawn a new generation of natural painkillers that relieve pain as well as morphine but without the addictive and psychological side effects of the traditional drug.
When the researchers injected a pain-inducing chemical into rats’ paws, 1 milligram of opiorphin per kilogram of body weight achieved the same painkilling effect as 3 milligrams of morphine.
The substance was so successful at blocking pain that, in a test involving a platform of upended pins, the rats needed six times as much morphine as opiorphin to render them oblivious to the pain of standing on the needle points.
Anti-depressive angle
“Its pain-suppressive effect is like that of morphine,” says Catherine Rougeot at the Pasteur Institute in Paris, France, who led the research. “But we have to test its side effects as it is not a pure painkiller,” she says. “It may also be an anti-depressive molecule.”
Rougeot and colleagues discovered that opiorphin works in nerve cells of the spine by stopping the usual destruction of natural pain-killing opiates there, called enkephalins.
Opiorphin is such a simple molecule that it should be possible to synthesise it and produce large quantities without having to isolate it from saliva, Rougeot explains. Alternatively, it might be possible to find drugs which trigger patients’ bodies to produce more of the molecule themselves.
Effects of Aerobic Exercise on Uric Acid, Total Antioxidant Activity, Oxidative Stress, and Nitric Oxide in Human Saliva
The aim of this study was to determine the effect of aerobic exercise on uric acid (UA), total antioxidant activity (TAA), lipid hydroperoxides, and nitric oxide (NO) metabolites in human saliva. Twenty-four healthy male and female subjects were studied during a 10,000-m race. Saliva samples were collected 1 h before and immediately after exercise. The NO concentration was determined by the Griess reaction, UA by enzymatic method, TAA by the ABTS method, and lipid hydroperoxide by the ferrous iron/xylenol orange (FOX) method. A repeated measures ANOVA was used to examine the effect of aerobic exercise on salivary UA, TAA, lipid hydroperoxides, and NO metabolites. Aerobic exercise caused an increase in both salivary UA and TAA, and a decrease in salivary lipid hydroperoxide. There was no, however, change in nitrite concentration. These results suggested that aerobic exercise-induced increment in both UA and TAA seems to inhibit lipid hydroperoxide generation, a marker of oxidative stress in human saliva.
Alternative Catalytic Anions Differentially Modulate Human α-Amylase Activity and Specificity
A mechanistic study of the essential allosteric activation of human pancreatic α-amylase by chloride ion has been conducted by exploring a wide range of anion substitutions through kinetic and structural experiments. Surprisingly, kinetic studies indicate that the majority of these alternative anions can induce some level of enzymatic activity despite very different atomic geometries, sizes, and polyatomic natures. These data and subsequent structural studies attest to the remarkable plasticity of the chloride binding site, even though earlier structural studies of wild-type human pancreatic α-amylase suggested this site would likely be restricted to chloride binding. Notably, no apparent relationship is observed between anion binding affinity and relative activity, emphasizing the complexity of the relationship between chloride binding parameters and the activation mechanism that facilitates catalysis. Of the anions studied, particularly intriguing in terms of observed trends in substrate kinetics and their novel atomic compositions were the nitrite, nitrate, and azide anions, the latter of which was found to enhance the relative activity of human pancreatic α-amylase by nearly 5-fold. Structural studies have provided considerable insight into the nature of the interactions formed in the chloride binding site by the nitrite and nitrate anions. To probe the role such interactions play in allosteric activation, further structural analyses were conducted in the presence of acarbose, which served as a sensitive reporter molecule of the catalytic ability of these modified enzymes to carry out its expected rearrangement by human pancreatic α-amylase. These studies show that the largest anion of this group, nitrate, can comfortably fit in the chloride binding pocket, making all the necessary hydrogen bonds. Further, this anion has nearly the same ability to activate human pancreatic α-amylase and leads to the production of the same acarbose product. In contrast, while nitrite considerably boosts the relative activity of human pancreatic α-amylase, its presence leads to changes in the electrostatic environment and active site conformations that substantially modify catalytic parameters and produce a novel acarbose rearrangement product. In particular, nitrite-substituted humnan pancreatic α-amylase demonstrates the unique ability to cleave acarbose into its acarviosine and maltose parts and carry out a previously unseen product elongation. In a completely unexpected turn of events, structural studies show that in azide-bound human pancreatic α-amylase, the normally resident chloride ion is retained in its binding site and an azide anion is found bound in an embedded side pocket in the substrate binding cleft. These results clearly indicate that azide enzymatic activation occurs via a mechanism distinct from that of the nitrite and nitrate anions.
Salivary -amylase: A measure associated with satiety and subsequent food intake in humans
Food intake regulation in humans involves various central and peripheral mechanisms. In this study salivary amylase was examined for functioning as a measure of satiety and food intake. In a 1.25-h session, 32 fasted subjects were given a preload of starch-based custard (849 kJ) followed by ad libitum intake of this custard. Before and after preload intake and after ad libitum consumption, both satiety ratings and -amylase were analysed. Perceived satiety and amylase were increased after preload and ad libitum consumption. Across subjects, the individual amount of ad libitum intake was negatively correlated to -amylase levels before this intake, whereas it was positively associated with -amylase activity after ad libitum consumption. In conclusion, salivary amylase systematically increases upon food consumption and satiation, and serves therefore as a potential measure of satiety and subsequent food intake.
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Formation of an adduct by clenbuterol, a β-adrenoceptor agonist drug, and serum albumin in human saliva at the acidic pH of the stomach
Clenbuterol (CLB) is an antiasthmatic drug used also illegally as a lean muscle mass enhancer in both humans and animals. CLB and amine-related drugs in general are nitrosatable, thus raising concerns regarding possible genotoxic/carcinogenic activity. Oral administration of CLB raises the issue of its possible transformation by salivary nitrite at the acidic pH of gastric juice. In acidic human saliva CLB was rapidly transformed to the CLB arenediazonium ion. This suggests a reaction of CLB with salivary nitrite, as confirmed in aerobic HNO2 solution by a drastic decrease in nitric oxide, nitrite, and nitrate. In human saliva, both glutathione and ascorbic acid were able to inhibit CLB arenediazonium formation and to react with preformed CLB arenediazonium. The effect of ascorbic acid is particularly pertinent because this vitamin is actively concentrated within the gastric juice. EPR spin trapping experiments showed that preformed CLB arenediazonium ion was reduced to the aryl radical by ascorbic acid, glutathione, and serum albumin, the major protein of saliva. As demonstrated by anti-CLB antibodies and MS, the CLB–albumin interaction leads to the formation of a covalent drug–protein adduct, with a preference for Tyr-rich regions. This study highlights the possible hazards associated with the use/abuse of this drug.
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Arsenic Speciation Analysis in Human Saliva
Background: Determination of arsenic species in human saliva is potentially useful for biomonitoring of human exposure and studying arsenic metabolism. Arsenic speciation in saliva has not been reported previously.
Methods: We separated arsenic species in saliva using liquid chromatography (LC) and quantified them by inductively coupled plasma mass spectrometry. We further confirmed the identities of arsenic species by LC coupled with electrospray ionization tandem mass spectrometry. These methods were successfully applied to the determination of arsenite (AsIII), arsenate (AsV), and their methylation metabolites, monomethylarsonic acid (MMAV), and dimethylarsinic acid (DMAV), in >300 saliva samples collected from people who were exposed to varying concentrations of arsenic.
Results: The mean (range) concentrations (µg/L) in the saliva samples from 32 volunteers exposed to background levels of arsenic were AsIII 0.3 [not detectable (ND) to 0.7], AsV 0.3 (ND to 0.5), MMAV 0.1 (ND to 0.2), and DMAV 0.7 (ND to 2.6). Samples from 301 people exposed to increased concentrations of arsenic in drinking water showed detectable AsIII in 99%, AsV in 98%, MMAV in 80%, and DMAV in 68% of samples. The mean (range) concentrations of arsenic species in these saliva samples were (in µg/L) AsIII 2.8 (0.1–38), AsV 8.1 (0.3–120), MMAV 0.8 (0.1–6.0), and DMAV 0.4 (0.1–3.9). Saliva arsenic correlated with drinking water arsenic. Odds ratios for skin lesions increased with saliva arsenic concentrations. The association between saliva arsenic concentrations and the prevalence of skin lesions was statistically significant (P <0.001).
Conclusions: Speciation of AsV, AsIII, MMAV, and DMAV in human saliva is a useful method for monitoring arsenic exposure.
Methods: We separated arsenic species in saliva using liquid chromatography (LC) and quantified them by inductively coupled plasma mass spectrometry. We further confirmed the identities of arsenic species by LC coupled with electrospray ionization tandem mass spectrometry. These methods were successfully applied to the determination of arsenite (AsIII), arsenate (AsV), and their methylation metabolites, monomethylarsonic acid (MMAV), and dimethylarsinic acid (DMAV), in >300 saliva samples collected from people who were exposed to varying concentrations of arsenic.
Results: The mean (range) concentrations (µg/L) in the saliva samples from 32 volunteers exposed to background levels of arsenic were AsIII 0.3 [not detectable (ND) to 0.7], AsV 0.3 (ND to 0.5), MMAV 0.1 (ND to 0.2), and DMAV 0.7 (ND to 2.6). Samples from 301 people exposed to increased concentrations of arsenic in drinking water showed detectable AsIII in 99%, AsV in 98%, MMAV in 80%, and DMAV in 68% of samples. The mean (range) concentrations of arsenic species in these saliva samples were (in µg/L) AsIII 2.8 (0.1–38), AsV 8.1 (0.3–120), MMAV 0.8 (0.1–6.0), and DMAV 0.4 (0.1–3.9). Saliva arsenic correlated with drinking water arsenic. Odds ratios for skin lesions increased with saliva arsenic concentrations. The association between saliva arsenic concentrations and the prevalence of skin lesions was statistically significant (P <0.001).
Conclusions: Speciation of AsV, AsIII, MMAV, and DMAV in human saliva is a useful method for monitoring arsenic exposure.
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