Scalp hair as an indicator of aluminium exposure: comparison to bone and plasma

1. Aluminium concentrations were measured in hair, plasma and bone samples from different groups of chronic renal insufficient patients and from a control group (75 healthy volunteers plus 21 deceased subjects). A cross-sectional study with 40 haemodialysis patients and two longitudinal studies were undertaken, the first comprising of 12 home haemodialysis patients and the second 16 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). 2. Before introduction of water treatment by reverse osmosis, the hair aluminium levels of home haemodialysis patients were elevated compared to controls. Aluminium in the hair of all other groups were within the normal range. Hair aluminium levels were not related to the daily aluminium intake, nor to the cumulative aluminium intake, nor to bone and plasma aluminium concentrations. 3. Plasma aluminium concentrations in all patients were higher than in the controls. Dialysis without reverse osmosis water treatment increased aluminium plasma levels. After installation of reverse osmosis units there was a decrease in the aluminium concentrations in plasma. In CAPD patients insignificant increases in the aluminium levels in plasma were observed. When low contaminated dialysis fluid was available the plasma aluminium concentrations returned to the initial level. 4. Aluminium concentrations in bone were increased in renal insufficient patients compared with controls. Aluminium bone content increased with increasing cumulative aluminium intake by phosphate binding therapy. 5. Hair analysis is of very limited value for the diagnosis of aluminium exposure. Bone analysis is suitable for the assessment of the individual body burden.

Uptake of aluminum, cadmium, copper, lead, and zinc by human scalp hair and elution of the adsorbed metals

Uptake of aluminum (Al), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) from aqueous solutions by human scalp hair (water/hair = 100:1) has been studied in the concentration range 0-50 mg/L. Hair metal levels were determined by a wet digestion procedure and atomic absorption spectrometry. Under conditions used, uptake followed a sigmoid concentration-response relationship. The order of binding capacity of hair to the metals was as follows: Al greater than Cd greater than Cu greater than Pb greater than Zn. Using logit transformation 50% saturation was evaluated at the following metal concentrations (hair metal concentration of saturation is given in parenthesis): 0.34 mg/L for Al (0.154 mg/g); 1.82 mg/L for Cd (0.363 mg/g); 2.21 mg/L for Cu (0.651 mg/g); 2.52 mg/L for Pb (0.986 mg/g); 23.84 mg/L for Zn (1.616 mg/g). Percentage elution of trace metals from hair after treatment with metal-enriched solutions by five different procedures ranged from 14.5 to 46.5% for Al, from 11.1 to 28.9% for Zn, from 11.5 to 28.4% for Pb, from 8.9 to 13.6% for Cd, and from 0.1 to 11.8% for Cu. In addition, trace element concentrations were measured in tap water samples and shampoos.

Two-dimensional electrophoretic analysis of human hair keratins, especially hair matrix proteins

Human hair keratins are composed of hair fibrous proteins (HFP) forming 10-nm filaments and nonfilamentous cysteine-rich hair matrix proteins (HMP); these proteins are highly cross-linked by disulfide bonds. In order to obtain high-resultional separation of HFP and HMP by two-dimensional polyacrylamide gel electrophoresis according to isoelectric point (IP) in the first dimension and molecular weight (MW) in the second dimension, these proteins were converted to S-carbamoylmethylated (SCam) derivatives with nonionizable iodoacetamide; this treatment hardly modified the electrophoretic mobility. SCam-HFP were separated into polypeptides with MW 41.5-59 kD (IP pH 5.1-6.8). SCam-HMP were subdivided into two groups; 14 polypeptides of acidic HMP with MW 15-28 kD (IP pH 5.0-7.0) and 12 polypeptides of basic HMP with MW 18.5-28 kD (IP pH 7.8-8.8). Variation in electrophoretic patterns among hair samples obtained from 15 persons in four Japanese families was found in acidic HMP, but not in HFP in basic HMP. The present method appears to be very suitable for the biochemical analysis of human hair keratins, especially HMP of nonfilamentous proteins.

Human scalp hair as evidence of individual dosage history of haloperidol: method and retrospective study

Hair samples and morning pre-dose plasma were collected from 40 patients who had received fixed daily doses of haloperidol for more than four months and whose compliance was good. After washing, 1 to 2 cm-long portions nearest to the roots of 2 to 3 strands of hair were completely dissolved in 2.5N NaOH. Haloperidol in that sample or alkalinised plasma was extracted and measured by RIA. Haloperidol concentrations in hair correlated well both with the trough concentration in plasma at steady-state (r = 0.772, n = 39) and with the daily dose (r = 0.555, n = 40). Another keratinized tissue, nail, was also collected from 20 of the 40 patients and the haloperidol level was compared with that in hair. The former was only about 4.3% of the latter and was significantly correlated only with the daily dose (r = 0.525, n = 20). Hair from 10 other patients in whom the dosage of haloperidol had been changed within a few months prior to sampling the hair was cut into 0.5 or 1 cm-long portions from the roots and the drug concentration in each portion was measured. If hairs were assumed to grow at 1 cm/month, a history of individual dosage could be deduced in 9 of the 10 patients from the distribution of drug level along the length of the hair. The results suggest that human scalp hair could serve as a useful tool for monitoring individual dosage history over several months, or in demonstrating exposure or non-exposure of a patient to a drug.

[Study of transverse sections and pigment granules of the hair of persons of various nationalities]

Data on the form of transversal sections and pattern of pigmental granulations of hair obtained from the inhabitants of some countries of Asia, Africa and Latin America are presented. These hair characteristics were compared to those of hair obtained from the USSR citizens (Russian, Buelorussian, Ukrainian, Georgian, Azerbaijanian people). Possibility of race identification of hair using set of morphological characteristics is stressed.

Hair copper and zinc concentrations in the Rett syndrome

The hair copper and zinc concentrations in patients with the Rett syndrome in 9 hospitals or institutions, and female age-matched controls were investigated. The copper and zinc concentrations in the 23 patients were 15.1 +/- 3.6 and 177 +/- 20 micrograms/g dry weight (mean +/- SD), respectively, and those in the 22 controls were 14.7 +/- 3.4 and 181 +/- 22, respectively. No significant differences were detected between the copper or zinc concentrations in the patients and controls. The copper and zinc concentrations did not change with age, or the hospital or institution. The ratio of the copper and zinc concentrations was also constant. We conclude that the hair copper and zinc concentrations in patients with the Rett syndrome are the same as those in controls.

Levels of zinc in plasma, erythrocytes, and hair, and levels of serum copper in patients with retinitis pigmentosa in Turkey

This study was made on 100 patients with retinitis pigmentosa and 23 of their relatives. Their plasma, erythrocyte, and hair Zn and serum Cu levels were compared with those of a control group of 14 healthy persons. No statistically significant difference in these levels was found between the patients with retinitis pigmentosa and the relatives or controls.

[Use of the isoelectric focusing method in examining hair proteins]

Method of isoelectric focusing in thin and ultrathin layer of polyacrylamide gel followed by staining the polypeptide fractions with argentum was used to investigate human hair keratins. Method makes it possible to determine the polymorphism of keratins in hair even 1,5-2 cm long. It helps to obtain the additional information in medicolegal expertise of hair affinity.

Integral lipids of mammalian hair

1. It has been demonstrated that hair contains lipids which cannot be removed by extensive extraction with chloroform-methanol mixtures. These integral lipids can be extracted only after the hair has been subjected to alkaline hydrolysis. 2. Integral hair lipids include cholesterol sulfate (0.7-2.9 mg/g hair), ceramides (0.6-1.4 mg/g), cholesterol (0.3-1.4 mg/g), fatty alcohols (trace-0.2 mg/g) and fatty acids (2.3-4.0 mg/g). 3. One of the major integral hair lipids, representing 38.4-47.6% of the total fatty acids, is the anteisobranched 18-methyleicosanoic acid. 4. The species examined included human (Homo sapiens), pig (Sus scrofa), dog (Canis familiaris), sheep (Ovis ammon aries) and cow (Bos taurus).

Indicators of lead, zinc and cadmium exposure in cattle: II. Controlled feeding and recovery

Two pre-exposed and 2 normal heifers were fed lead (Pb), zinc (Zn), and cadmium (Cd) polluted hay (500 g/100 kg body weight) over a 17-week period. They were then examined over a 10-month period (42 or 38 weeks) to study the decay of the indicators of exposure. The elimination pattern of blood Pb and Zn protoporphyrin concentrations displayed a very slow decay. A bi-exponential equation, with the half-times of the fast component set at approximately 1 week, and the half-times of the slow component set from 3 mo to 2 years, was fitted to blood Pb levels. In man, the half-life of the slow component is still longer (2 to 15 years). This slow elimination rate represents release of Pb from skeleton, which in bovines, may accumulate up to 100 ppm Pb/dry or more. Lead concentrations in the hair were not proportionate to the areas under the curves of blood Pb levels; there was the same lack of correlation concerning skeleton and viscerae Pb levels. The withdrawal of contaminated hay from the diet resulted in a significant increase in blood copper. This is in accordance with the depressive effect of Pb and Zn on the bioavailability of this metal.

Analytical problems encountered in determining aluminum status from hair in controls and hemodialyzed patients

The problems involved in evaluating aluminum concentrations in hair are reviewed, especially those concerning removal of contaminating metals, a critical factor. In the few published studies of Al concentrations in hair, acetone was usually used for its removal. Here, its use in the washing sequence was found to give less precise results and higher Al values than the use of isopropanol. With isopropanol, the whole analysis can be done in a single tube. We compared results with those in the literature. We found that the Al concentration in the hair of control subjects was not related to sex or hair color and that there was a highly significant (P less than 0.001) difference between values for control subjects and hemodialyzed patients: 126 (SD 58) nmol/g, n = 49, vs 226 (SD 104) nmol/g, n = 39, respectively.

Hair trace elements and mental retardation among children

The calcium, magnesium, zinc, iron, and copper content found in scalp hair of 40 children with mental retardation were compared with 37 healthy normal children who were between the ages of 4 and 14 yr. The hair of children with mental retardation showed significantly lower levels of iron, copper, and magnesium (p less than .001) and higher levels of calcium (p less than .001). The zinc content did not differ between the two groups. The differences in levels of hair trace elements between normal children and those with mental retardation could be of particular interest in the investigation of the cause of mental retardation among children.

Zinc in hair and serum of obese individuals in Taiwan

Zinc concentrations in both serum and hair were assessed in 135 obese patients (51 males, 84 females) and in 57 controls (28 males, 29 females) to study the correlation between Zn and obesity. The body mass index (wt/ht2) was also measured to evaluate its relationship to the Zn level in obese individuals. The serum and hair Zn contents in obese patients were markedly lower than in normal control subjects by 22 and 34%, respectively. The Zn content was inversely related to the body mass index. Thus Zn may play an important metabolic role in the development of obesity.

Hair protein glycation as a long-term index of blood glucose in diabetics

We used furosine, which is derived from fructose-lysine and is a glycation product, to measure the extent of hair protein glycation in diabetic patients. We took hair samples that were 12 cm long, corresponding roughly to 1 year's growth. While the furosine levels in these samples correlated poorly with fasting plasma glucose (FPG) and with hemoglobin A1c (HbA1c) levels at the time of sampling, better correlations were observed between glycation and the year-long average values of FPG, HbA1c, and the conduction velocities in two peripheral nerves. The glycation levels in these samples may thus reflect the year-long average of the patient's blood glucose. Hair glycation may serve as a valuable indicator both of long-term blood glucose trends and of the relationship between diabetic complications and blood glucose.

Utilization and requirement of dietary protein taking into account the dermal and miscellaneous nitrogen losses in Japanese women

Utilization and requirement of mixed protein in the conventional Japanese diet and the obligatory integumental and miscellaneous nitrogen losses were measured in female subjects. Twelve female students aged 18 to 24 years were given conventional low-protein diets at N intake levels of 50, 70, and 90 mg/kg/day for 10 days. Constituents of the diets corresponded to those of average intake of the Japanese in recent years (1982). N balances were estimated and regression equations between N intake (X) and N balance (Y) were calculated by the multiple level-constant variation method. The equation was Y = 0.426X - 40.0 (n = 36, r = 0.615, p less than 0.01) and the intersection of the regression line with zero nitrogen balance was 93.9 +/- 14.3 mg N/kg/day. The mean digestibility was 92.2 +/- 4.7%. In another experimental group, nitrogen losses due to hair, nails, and menstruation in ten Japanese women were 0.624 +/- 0.172, 0.020 +/- 0.005, and 1.76 +/- 0.68 mg/kg/day, respectively. In a third experimental group, mean of the integumental N losses was 2.8 mg/kg/day in both the subjects given a low-protein diet (19 women) and an ordinary-protein diet (4 women). It increased to 12.7 mg N/kg/day when subjects exercised in summer (4 subjects). The protein requirement in the conventional Japanese diet estimated as the sum of the mean requirement of dietary protein and obligatory dermal and miscellaneous nitrogen losses in Japanese women was 99.1 mg N/kg/day or 0.62 g protein/kg/day. The net protein utilization (NPU) of the proteins at the N intake level for N equilibrium was estimated as 48.

Mouse hair keratin cDNA: implications and sequences

An efficient method is described for the isolation of mouse hair follicle mRNAs. The RNA contains two peaks of mRNA activity, 11S and 18S. The larger-sized group of mRNAs encodes keratins of 46K, 47K, 58K, 59K, and 63K Mr. cDNAs were prepared using the follicular mRNAs as templates and cloned to produce a library. Initial screening of this library has identified five acidic and six basic mouse hair keratin clones.

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Optical isomers (d and l) and racemic compounds (dl) of methamphetamine (MAMP) and amphetamine (AMP), and biologic materials including those substances, could be analyzed by high performance liquid chromatography. Examining the temperature for the analysis, 40 degrees C was the optimal condition in the reproducibility of separated MAMP-isomers. The reproducibility at the temperature did not vary significantly. The measured values of optical isomers were 0.116 +/- 0.012, 1.082 +/- 0.070 and 8.984 +/- 0.136 for the mixing ratios (l/d) of 0.111, 1.000, and 9.000, respectively. The detection limit for both d- and l-isomers was 25 ng. The analytic result of hair specimens from two stimulant abusers by the present method indicates that they contained only d-MAMP and d-AMP, which is believed to have the strongest pharmacologic effect among the optical isomers of MAMP. The coefficient of variation in the analysis of five replicate standards, prepared by adding 1,000 ng each of racemate MAMP and AMP to hair, was less than 4%. The measured value against l/d = 1.000 was 1.040 +/- 0.040 in MAMP and 0.980 +/- 0.030 in AMP. The detection limit for both racemate MAMP and AMP accumulated in hair was 250 ng. The analysis of the optical isomers by our method would contribute to identifying the smuggling routes or the illicit method.

Trace element content in fingernails and hair of a nonindustrialized US control population

The concentrations of 17 elements in the nail and hair of 117 subjects from a nonindustrialized environment were determined by instrumental neutron activation analysis (INAA). A new method of statistical treatment that allows for more meaningful use of detection limit values was used to process the concentration data. Geometric means and standard errors are presented for each element, along with a summary of the effects of age, sex, and treatment on the concentration of each element. For nails, these data represent the first comprehensive study for several important elements. Correlations for each element between hair and nail were determined. With few exceptions, concentrations of nonessential trace elements were positively correlated in hair and nail, whereas concentrations of essential elements showed no correlations. The factors affecting concentrations and control levels must be considered in studying alterations in disease states.

Integral lipids of human hair

It has long been recognized that hair is coated with nonpolar lipids originating in the sebaceous glands, and recently it has been shown that hair also contains cholesterol sulfate and small amounts of ceramides, similar to those found in the keratinized portion of the epidermis. In the present study, it is demonstrated that significant amounts of several additional lipids are tightly associated with hair in such a way as to be highly resistant to solvent extraction. These integral hair lipids included cholesterol sulfate (3.3 mg/g of extracted hair), cholesterol (0.6 mg/g), fatty alcohols (0.2 mg/g) and free fatty acids (4.3 mg/g). The principal fatty acid, comprising 40% of the total fatty acids, was identified as 18-methyl-eicosanoic acid by cochromatography with authentic standard on gas-liquid chromatography (GLC) and by mass spectrometry (MS).

Effect of dietary manipulations (fasting, hypocaloric feeding, and subsequent refeeding) on rat muscle energetics as assessed by nuclear magnetic resonance spectroscopy

31P nuclear magnetic resonance (NMR) spectroscopy in vivo and fluorometry were used to measure muscle ATP, total creatine, pH, and Mg2+ in vivo; and to calculate creatine phosphate (CrP), the ratios of CrP/inorganic phosphate (Pi), CrP/ATP, free ADP levels, and the free-energy change in ATP hydrolysis so nutritional effects could be ascertained. These parameters were determined in vivo in resting control, 2-d-fasted, and hypocalorically fed rats and in animals similarly hypocalorically fed and then refed. The ATP, Pi, and intracellular Mg2+ levels were comparable in the four groups. When the fasted and underfed animals were compared with the control and refed animals, there were falls in the ratios of CrP/Pi and CrP/ATP, in the calculated CrP, and the free-energy change of ATP hydrolysis, but a rise in the calculated free ADP. In the hypocaloric group, intracellular pH fell significantly and a large peak was noted in the phosphodiester region. The data are consistent with the hypothesis that ATP levels are maintained at the cost of CrP, suggesting that ATP production is disturbed by aerobic and anaerobic mechanisms.

A study of mercury in the hair of dentists and dental-related professionals in 1985 and subcohort comparison of 1972 and 1985 mercury hair levels

Dentists may be exposed to mercury used in dental restorations. An epidemiologic study was conducted in central New York in 1985 comparing the concentration of mercury in the hair of 85 dentists to that of 23 dental-related health professionals (mainly orthodontists and oral surgeons) who do not use mercury. Mercury in the hair of dentists was nominally higher (2.98 +/- 0.57 ppm, mean +/- SE) than that of the control group (1.84 +/- 0.20 ppm) but not significantly so. There was a significant positive linear trend in the concentration of mercury in the dentists' hair with the number of years they had been in practice. Those dentists who wore masks when removing old mercury containing fillings showed significantly (p = 0.03) lower mercury concentrations in hair (1.7 +/- 0.26 ppm, mean +/- SE) than those who did not (3.65 +/- 0.85 ppm). Mercury concentration in the hair of 23 of the above dentists analyzed in 1972 was 16.77 +/- 4.00 ppm (mean +/- SE), significantly higher (p = 0.008) than that of the same dentists in 1985 (5.27 +/- 1.85 ppm). The reduction is believed due to the currently used pre-prepared disposable or reusable capsules containing the amalgam versus formerly mixing the ingredients manually. This may also account for the lack of a significant difference in mercury in the hair of the dentists versus that of the control group in 1985. The statistical relationships between mercury concentrations in hair of the two groups and reported health effects, as well as other factors including fish consumption, number of restorations per day, office floor covering, and urban or rural domicile, are discussed.

5 alpha-cholest-8(14)-en-3 beta-ol-15-one, a potent regulator of cholesterol metabolism: occurrence in rat skin

5 alpha-Cholest-8(14)-en-3 beta-ol-15-one is a potent inhibitor of cholesterol biosynthesis which has significant hypocholesterolemic activity upon oral administration to animals. Described herein are the results of experiments that indicate the presence of the 15-ketosterol in rat skin. The 15-ketosterol was, after purification by medium pressure liquid chromatography on Lichroprep RP-8 columns, thin-layer chromatography on silica gel G, and reverse phase high performance liquid chromatography, characterized by gas-liquid chromatography-mass spectrometry in the form of its trimethylsilyl ether derivative. The use of an internal standard containing both tritium and deuterium permitted the determination of the levels of the 15-ketosterol by mass fragmentography. The results of five separate analyses of portions of the skin of a male Sprague Dawley rat showed a mean value of 84.5 +/- 4.1 (SEM) ng per g. Analyses of hair samples of ten male Sprague Dawley rats indicated a mean level of 143 +/- 19 (SEM) ng per g of hair. Most (approximately 72%) of the 15-ketosterol in hair was esterified. This report constitutes the first isolation of the 15-ketosterol from animal tissues.

Copper in urine and hair in Indian childhood cirrhosis

In advanced Indian childhood cirrhosis (ICC) urine copper concentration was higher (range 416-103,448 mg/g creatinine) than in other hepatic diseases (range 67-10,303 mg/g creatinine). In early ICC urine copper concentration was more modestly raised (1188-9470 mg/g creatinine), but rose to high values (2222-42,819 mg/g creatinine) after a single dose of penicillamine 20 mg/kg. A post-penicillamine urinary copper:creatinine ratio greater than 10,000 mg/g supports a diagnosis of ICC. The concentration of copper in the hair, while increased in advanced ICC, is of no diagnostic value in early cases.

[A review of the literature on the concentration of arsenic, lead, cadmium and mercury in body fluids and tissues for the localization of normal values and the detection of body burden. 2. Cadmium]

The 2nd of 4 communications on metal concentrations in human body media deals with cadmium. Publications obtained from a comprehensive data bank search from January 1980 to April 1984 are listed in tables; study groups have been assigned to the following categories: normal; exposed; and exposed, exhibiting adverse health effects. Quality and strength of evidence of analytical procedures and reported data are discussed, particularly in light of adverse health effects. General methods and individual analytical procedures were presented in the 1st communication, a summary of mean exposure levels, critically elevated levels, and references will be published in the 4th communication.

[A study of the literature on the concentrations of arsenic, lead, cadmium and mercury in body fluids and tissues to define normal values and detection of overload. 1. Description of analytical methods and arsenic]

The present review covers 208 papers dealing with determination of the metals arsenic, cadmium, lead and mercury in human biologic material. A comprehensive data bank survey of the literature from January 1980 to April 1984 was conducted and supplemented by review of some earlier publications. As shown by comparison of the results from a number of papers, the various state-of-the-art methods for determining metal content in biologic materials (e.g., atomic absorption spectrophotometry, neutron activation analysis, and x-ray fluorescent analysis) appear to be equally sensitive and reliable. These detection methods are suited to determination of the above metals in the following media: arsenic in urine, hair; cadmium in blood, urine, hair, renal cortex; lead in blood, hair; mercury in blood, urine, hair. To permit better comparison of the results presented in various publications, agreement must be reached on use of uniform concentration units and participation in quality control programs. Safe levels of chronic biological exposure overlap with concentrations which cause health effects or measurable impairment of body function over a wide range. Individual sensitivity to biological exposure varies. In a number of studies, metal concentrations are measured in symptom-free persons which cause symptoms in persons examined in other studies. Due to differences in the sensitivity of detection of symptoms, the range of minimum levels of biological exposure considered to be associated with deleterious health effects (levels of critical exposure) is unacceptably broad. Minimum levels of critical exposure should protect against development of early symptoms of toxicity. If the lowest published critical levels of biological exposure are taken as a cutoff, then a sizable portion of the persons currently revealing metal exposure in any of the reported media exceeds such levels. Symptoms of detrimental effects should be detectable in such persons and should be investigated. In establishing and evaluating current minimum levels of critical chronic metal exposure, there is a general need for a quantitative increase in determinations and for a qualitative increase in the sensitivity of detection of symptoms and other health effects--in order to avoid dependence on reports of acute toxicity. When detected levels of a given metal are in a range held to be normal, exclusion of toxic effects and poisoning requires additional consideration of clinical findings.

Persistence of an allergen in hair after glyceryl monothioglycolate-containing permanent wave solutions

Glyceryl monothioglycolate, a reducing agent used in permanent waving solutions, is a recognized cause of allergic contact dermatitis. Because of an unexplained persistence of dermatitis in beauty shop clients after exposure to permanent wave solutions containing glyceryl monothioglycolate, we looked for the presence of this or a cross-reacting substance in permanent-waved hair as a possible source of continued exposure to the allergen. Seventeen subjects sensitive to glyceryl monothioglycolate underwent patch testing with hair samples collected before and at various times after a permanent wave containing glyceryl monothioglycolate. None reacted to hair that had not received a permanent, while 7 of 17 showed positive reactions to the permanent-waved hair. Positive reactions were seen in hair collected as long as 3 months after the permanent. This suggests that a glyceryl monothioglycolate-related allergen is retained in hair for up to 3 months after the permanent, which may explain the long-lasting dermatitis that occurs in clients sensitive to glyceryl monothioglycolate.

[Mercury levels in urine and head hair of dental personnel]

As dentists and their assistants are usually exposed to mercury in their clinical practices. The objective was to investigate the mercury level in these dental personnel. Urine and head hair samples were collected from 201 dental personnel and 57 unexposed controls for mercury analysis. The mercury content was analyzed by using cold vapour atomic absorption spectrophotometry. The results showed that mercury levels in the urine and head hair of dental personnel were significantly higher than in the controls (P less than 0.01). The urine mercury concentration of the unexposed controls ranged from 0.1-10.0 micrograms/l (means = 2.6 +/- 0.29 micrograms/l). The highest urine mercury level was found in the group of dental assistant (means = 17.1 +/- 2.44 micrograms/l). The mean urine mercury levels found in dentists, dental students and dental technicians were 10.1 +/- 1.42, 11.1 +/- 1.69 and 3.2 +/- 0.69 micrograms/l respectively. The amounts of urine mercury from dental assistants, dentists and dental students were 81.0%, 38.2% and 43.5% higher than the threshold limit value respectively. The mean head hair mercury concentration of unexposed controls ranged from 0.3-12.2 micrograms/g (means = 2.8 +/- 0.36 micrograms/g). The highest head hair mercury concentration was found in the group of dental assistant and 6th year dental students (means = 10.1 +/- 0.84 and 10.5 +/- 3.2 micrograms/g). The mean head hair mercury levels found in dental assistants, dentists, dental students and dental technicians were 10.1 +/- 0.84, 7.5 +/- 1.2, 6.5 +/- 1.54 and 2.8 +/- 0.53 micrograms/g respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Simple non-invasive method to obtain DNA for gene analysis

A technique is described which demonstrates that sufficient human DNA for direct gene analysis can be isolated from buccal epithelial cells obtained by mouthwash. This procedure is much simpler and cheaper than existing methods and, combined with DNA amplification by polymerase chain reaction, should allow community screening for carrier status for single gene defects such as cystic fibrosis.

Neonatal and maternal hair zinc levels in a nonhuman primate model of the fetal alcohol syndrome

The role of zinc deficiency in the etiology of ethanol-associated fetotoxicity was assessed by measurement of maternal and newborn hair zinc content in a nonhuman primate model of the fetal alcohol syndrome. The model best approximates the human situation for length of gestation and type of placentation, coupled with the ability to control for nutritional factors. All mothers received 110% of their minimum daily caloric requirements as a balanced, nutritionally complete diet, including a minimum of 3.5 mg zinc per day. Over a 2-year period, maternal hair samples from 17 pregnancies (using 12 females) were obtained at term. There were 16 live, full-term neonates (nine ethanol exposed and seven control) from whom samples were taken within 1 hr of birth. The ethanol-exposed infant monkeys had a significantly higher incidence of craniofacial dysmorphology and developmental delay compared to the controls. There was no difference in hair zinc levels between ethanol-exposed and control animals for either the mothers or the newborns. Neonatal levels were, however, consistently higher than corresponding maternal. Although the findings cannot exclude transient or early gestational zinc deficiency as a factor, they provide further evidence that ethanol (and/or its metabolites) is the proximate toxin in the type of fetal injury seen in the fetal alcohol syndrome.