Nail analysis for drugs of abuse: extraction and determination of cannabis in fingernails by RIA and GC-MS. (1/378)

Fingernail clippings were evaluated as analytical specimens for the detection and quantitation of cannabinoids. Specimens were obtained from consenting adults attending a drug clinic, along with information concerning the drugs which they had used over the previous six months. Methods for the surface decontamination and extraction of the specimens were evaluated. Detergent, water, and methanol washes followed by alkaline hydrolysis and liquid-liquid extraction were selected for use in the study. Extracts were analyzed by radioimmunoassay (RIA) and gas chromatography-mass spectrometry (GC-MS) to detect and quantitate cannabinoids present in fingernail clippings. Positive RIA results were obtained from specimens from six known cannabis users. The mean cannabinoid concentration in fingernail clippings determined by RIA was 1.03 ng/mg. Using GC-MS, the mean delta9-tetrahydrocannabinol concentration in fingernail clippings from a further 14 known cannabis users was 1.44 ng/mg. Using GC-MS, the average 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid concentration in fingernail clippings from three known cannabis users extracted in acidic pH was 19.85 ng/mg. Based on these results, fingernails are potentially useful biological specimens for the detection of past cannabis use in cases of medicolegal interest.  (+info)

Influence of drinking water and diet on the stable-hydrogen isotope ratios of animal tissues. (2/378)

Despite considerable interest in using stable-hydrogen isotope ratio (deltaD) measurements in ecological research, it was previously unknown whether hydrogen derived from drinking water, in addition to that derived from diet, contributed to the nonexchangeable hydrogen in animal tissues. We raised four experimental groups of quail (Coturnix coturnix japonica) from hatch on two isotopically distinct diets (mean nonexchangeable deltaD: -146 and -60 per thousand, Vienna Standard Mean Ocean Water Standard) and drinking waters (mean deltaD: -130 and +196 per thousand, Vienna Standard Mean Ocean Water Standard). Here we show that both dietary and drinking water hydrogen are incorporated into nonexchangeable hydrogen in both metabolically active (i.e., muscle, liver, blood, fat) and inactive (i.e., feather, nail) tissues. Approximately 20% of hydrogen in metabolically active quail tissues and 26-32% of feathers and nail was derived from drinking water. Our findings suggest environmental interpretations of deltaD values from modern and fossil animal tissues may need to account for potentially large isotopic differences between drinking water and food and require a good understanding of the physiological ecology of study organisms.  (+info)

Helicobacter pylori infection in indigenous families of Central America: serostatus and oral and fingernail carriage. (3/378)

Helicobacter pylori infection remains one of the most common in humans, but the route of transmission of the bacterium is still uncertain. This study was designed to elucidate possible sources of infection in an isolated, rural population in Guatemala. A total of 242 subjects in family units participated in the study. A medical history, including a history of dyspepsia, was taken by a physician and immunoglobulin G antibodies to H. pylori were detected with the QuickVue (Quidel, San Diego, Calif.) onsite serology test. Overall, 58% of subjects were seropositive, with a positive relationship between mother and child (P = 0.02) and a positive correlation between the serostatuses of siblings (intraclass correlation coefficient = 0.63). There was no association between serostatus and gastric symptoms. Oral H. pylori was detected from periodontal pockets of various depths and the dorsum of the tongue by nested PCR. Eighty-seven percent of subjects had at least one oral site positive for H. pylori, with the majority of subjects having multiple positive sites. There was no association between periodontal pocket depth and the detection of H. pylori. Nested PCR was also used to detect H. pylori from beneath the nail of the index finger of each subject's dominant hand. Overall, 58% of subjects had a positive fingernail result, with a significant positive relationship between fingernail and tongue positivity (P = 0.002). In conclusion, the results of this study suggest that oral carriage of H. pylori may play a role in the transmission of infection and that the hand may be instrumental in transmission.  (+info)

Hydration of human nails investigated by NIR-FT-Raman spectroscopy. (4/378)

The human nail, although it is usually stable against outer influences, becomes soft and flexible after soaking in water. Frequent washing increases brittleness of nails. Hydration of nails is thought to be the most important factor influencing the physical properties of nails and possibly acts through changes in keratin structure. Here NIR-FT-Raman has been used to examine molecular structural changes of intact moisten nails. Raman spectra were obtained both in vitro from nail samples and in vivo before and after soaking in water. The water uptake of normal nail samples during the first 15 min was reflected in the increasing intensity ratio of the nu(OH)/nu(CH(2)) bands. A saturating effect appeared soon after 10 min which is explained by a defined water holding capacity. R(nu) representation of the low frequency range of the Raman spectra showed that mainly bound water is found both in dry and in wet nails. This implies water-protein interaction. Protein backbone vibration at 932 cm(-1) indicating alpha-helical proteins increased in intensity in the wet nails. The nu(S-S) which is sensitive to changes in conformation of proteins showed a 4% higher intensity. Additional protein-water interactions could lead to a slight change of the dihedral angle of the C-S-S-C bonds and to geometric changes in coiling behavior of the alpha-helical protein. Suggesting a separation between matrix proteins and fiber proteins giving them a greater freedom of flexibility. The in vivo spectra detected from the distal part of the nail resembled spectra in vitro. Raman spectra of the proximal part of the nail showed that it was fully saturated with water. The proximal part of the nail did not show changes in water content and protein structure during nail moisturizing in the Raman spectra. Our results suggest that the softening of the nail following hydration may be due to changed matrix protein molecular structure induced by water.  (+info)

Clinical pallor is useful to detect severe anemia in populations where anemia is prevalent and severe. (5/378)

Clinical pallor is recommended as a simple way to detect severe anemia, but more data are needed on its accuracy and usefulness when assessed by nonphysicians in diverse settings. We measured hemoglobin and trained non-physician health workers to assess clinical pallor of the conjunctiva, palm and nail beds in five population samples in Nepal and Zanzibar, where severe anemia is common. In total, 5,760 individuals were examined, 3,072 of whom were anemic and 192 of whom had severe anemia (hemoglobin <70 g/L). The prevalence of pallor did not correspond to the prevalence of anemia or severe anemia in the groups studied. However, in all studies, pallor at each anatomical site was associated with a significantly lower hemoglobin concentration. The relative performance of different anatomical sites was not consistent among studies, and we recommend that multiple sites be assessed. Pallor at any of the three sites detected severe anemia with >84% specificity. However, the sensitivity varied from 81% in Nepalese postpartum women to 29% in Zanzibari preschoolers in 1996. Overall estimates for sensitivity and specificity were 50 and 92%, respectively. Although imperfect, use of pallor to screen and treat severe anemia by primary care providers is feasible and worthwhile where severe anemia is common. Usually, the majority of persons with severe anemia will be detected at practically no cost. Many people who are not severely anemic will also receive treatment, but the costs of this error are low compared to the benefits.  (+info)

Microvascular abnormalities in Sjogren's syndrome: nailfold capillaroscopy. (6/378)

OBJECTIVE: To describe microvascular abnormalities by nailfold capillaroscopy in patients with primary Sjogren's syndrome (SS) with or without Raynaud's phenomenon (RP) and those with anticentromere antibodies (ACA). METHODS: Forty patients with SS (14 without RP, 16 with RP, 10 with ACA), 20 patients with scleroderma (SSc) (10 with limited and 10 with diffuse disease) (disease control group) and 40 healthy controls (control group) were evaluated by nailfold capillaroscopy. RESULTS: Capillaroscopic abnormalities in SS ranged from non-specific findings (crossed capillaries) to more specific findings (confluent haemorrhages and pericapillary haemorrhages) or scleroderma-type findings. SS patients with RP presented capillary abnormalities in higher frequency than patients without RP. The majority of SS patients with ACA (80%) presented scleroderma-type findings. CONCLUSION: Nailfold capillaroscopy can be used as a simple non-invasive method to evaluate the microvascular abnormalities in SS patients, especially in those with RP and those with ACA.  (+info)

Groundwater arsenic contamination in Bangladesh and West Bengal, India. (7/378)

Nine districts in West Bengal, India, and 42 districts in Bangladesh have arsenic levels in groundwater above the World Health Organization maximum permissible limit of 50 microg/L. The area and population of the 42 districts in Bangladesh and the 9 districts in West Bengal are 92,106 km(2) and 79.9 million and 38,865 km(2) and 42.7 million, respectively. In our preliminary study, we have identified 985 arsenic-affected villages in 69 police stations/blocks of nine arsenic-affected districts in West Bengal. In Bangladesh, we have identified 492 affected villages in 141 police stations/blocks of 42 affected districts. To date, we have collected 10,991 water samples from 42 arsenic-affected districts in Bangladesh for analysis, 58,166 water samples from nine arsenic-affected districts in West Bengal. Of the water samples that we analyzed, 59 and 34%, respectively, contained arsenic levels above 50 microg/L. Thousands of hair, nail, and urine samples from people living in arsenic-affected villages have been analyzed to date; Bangladesh and West Bengal, 93 and 77% samples, on an average, contained arsenic above the normal/toxic level. We surveyed 27 of 42 districts in Bangladesh for arsenic patients; we identified patients with arsenical skin lesions in 25 districts. In West Bengal, we identified patients with lesions in seven of nine districts. We examined people from the affected villages at random for arsenical dermatologic features (11,180 and 29,035 from Bangladesh and West Bengal, respectively); 24.47 and 15.02% of those examined, respectively, had skin lesions. After 10 years of study in West Bengal and 5 in Bangladesh, we feel that we have seen only the tip of iceberg.  (+info)

Keratin 17 expression in the hard epithelial context of the hair and nail, and its relevance for the pachyonychia congenita phenotype. (8/378)

The hard-keratin-containing portion of the murine hair shaft displays a positive immunoreactivity with an antibody against the soft epithelial keratin, K17. The K17-expressing cell population is located in the medulla compartment of the hair. Consistent with this observation, K17-containing cells also occur in the presumptive medulla precursor cells located in the hair follicle matrix. Western blot analysis of hair extracts prepared from a number of mouse strains confirms this observation and suggests that K17 expression in the hair shaft is a general trait in this species. The expression of K17 in human hair extracts is restricted to eyebrow and facial hair samples. These are the major sites for the occurrence of the pili torti (twisted hair) phenotype in the type 2 (Jackson-Lawler) form of pachyonychia congenita, previously shown to arise from inherited K17 mutations. Given that all forms of pachyonychia congenita show an involvement of the nail, we compared the expression of the two other genes mutated in pachyonychia congenita diseases, K6 and K16, with that of K17 in human nail. All three keratins are abundantly expressed within the nail bed epithelium, whereas K17 protein is expressed in the nail matrix, which contains the epithelial cell precursors for the nail plate. Our data suggest a role for K17 in the formation and maintenance of various skin appendages and directly support the concept that pachyonychia congenita is a disease of the nail bed.  (+info)