Comparison of organophosphorus pesticide metabolite levels in single and multiple daily urine samples collected from preschool children in Washington State

A total organophosphorus pesticide exposure study was conducted in Washington State in 1998 in a sample population of 13 children aged 2.5-5.5 years. The children were roughly split between rural and suburban populations and had been previously identified as having potentially elevated organophosphorus pesticide exposures. One component of the study was urine collection and analysis. Urine samples were collected from each subject up to four times in 24 h in two different seasons. Samples were collected at specific time points: before bed, first morning void, after lunch, and before dinner. Urine samples were analyzed initially for the six nonspecific dialkylphosphate (DAP) metabolites and subsequently for eight specific metabolites including malathion dicarboxylic acid (MDA), 3,5,6-trichloro-2-pyridinol (TCPy), and paranitrophenol (PNP). Relatively large percentages of the urine samples contained quantifiable amounts of two of the nonspecific DAP metabolites (DMTP-97%; DETP-67%), and three of the specific metabolites (MDA (71%), TCPy (79%), and PNP (96%)). A percent deviation analysis was employed to determine which of the spot sample time points was the best predictor of the estimated volume-weighted daily average. Of the four spot samples collected, first morning void samples were consistently found to be the best predictors of weighted-average daily metabolite concentration. This finding also held when the data were creatinine-adjusted. The results of this analysis suggest that if spot sampling is to be conducted as part of a biological monitoring study, first morning void samples should be preferentially collected.     

Reliability of a device measuring triceps surae muscle fatigability

OBJECTIVE: To examine the test-retest reliability of a protocol using an apparatus designed to standardise the standing heel rise test for the triceps surae muscle. SUBJECTS: 40 healthy subjects volunteered to test short and medium term test-retest reliability (group SM, median age 24 years), and a convenience sample of 38 subjects with a history of unilateral deep vein thrombosis (DVT) volunteered to test long term test-retest reliability (group L, median age 52 years). DESIGN: Subjects carried out 23 heel rises per minute until either the pace or the height could no longer be maintained. Group SM subjects repeated the test 30 minutes later (short term), and again 48 hours later (medium term). Subjects in group L did the test on the unaffected leg, and repeated the test one week later (long term). RESULTS: The median number of heel rises achieved per trial in group SM was 34 (range 16 to 120). The intraclass coefficient (ICC) was 0.93 (SEM 2.1) for both 30 minute and 48 hour test-retest reliability. In group L, the median number of heel rises was 27 (range 9 to 97), with ICC 0.88 and SEM 3.4. CONCLUSIONS: The apparatus is a simple and inexpensive standardised tool that reliably measures triceps surae fatigability in subjects with no current injury. Future research should assess its use in injured patients.     

Ethanol sclerotherapy of peripheral venous malformations

BACKGROUND: Venous malformations are congenital lesions that can cause pain, decreased range of movement, compression on adjacent structures, bleeding, consumptive coagulopathy and cosmetic deformity. Sclerotherapy alone or combined with surgical excision is the accepted treatment in symptomatic malformations after failed treatment attempts with tailored compression garments. OBJECTIVES: To report our experience with percutaneous sclerotherapy of peripheral venous malformations with ethanol 96%. PATIENTS AND METHODS: 41 sclerotherapy sessions were performed on 21 patients, aged 4-46 years, 15 females and 6 males. Fourteen patients were treated for painful extremity lesions, while five others with face and neck lesions and two with giant chest malformations had treatment for esthetic reasons. All patients had a pre-procedure magnetic resonance imaging (MRI) study. In all patients, 96% ethanol was used as the sclerosant by direct injection using general anesthesia. A minimum of 1-year clinical follow-up was performed. Follow-up imaging studies were performed if clinically indicated. RESULTS: 17 patients showed complete or partial symptomatic improvement after one to nine therapeutic sessions. Four patients with lower extremity lesions continue to suffer from pain and they are considered as a treatment failure. Complications were encountered in five patients, including acute pulmonary hypertension with cardiovascular collapse, pulmonary embolus, skin ulcers (two) and skin blisters. All patients fully recovered. CONCLUSION: Sclerotherapy with 96% ethanol for venous malformations was found to be effective for symptomatic improvement, but serious complications can occur.     

Sleep disorders and daytime sleepiness in children with attention-deficit/hyperactive disorder

STUDY OBJECTIVES: Children with attention-deficit/hyperactive disorder (ADHD), in spite of being hyperactive, still benefit from treatment with stimulant medications. We hypothesized that children with ADHD are in fact sleepy during the day, and we sought to test it objectively. DESIGN: Single blind comparative study SETTING: University medical center PARTICIPANTS: Thirty-four children with a previous diagnosis of ADHD (mean age +/- SD, 12.4 +/- 4.6 years) and 32 matched controls (mean age, 12.0 +/- 3.6 years). INTERVENTIONS: N/A. MEASUREMENTS: All participants underwent a full-night polysomnographic study followed by a multiple sleep latency test (MSLT). RESULTS: Sleep latency, total sleep time, and sleep efficiency were comparable between the groups, yet children with ADHD were significantly sleepier during the day than those in the control group (mean MSLT score of 21.9 +/- 5.5 minutes versus 27.9 +/- 2.0 minutes, P < .005). Of the children with ADHD, 17 (50%) had signs of sleep-disordered breathing, compared with 7 of the control group (22%, P < .05). Five of the ADHD group had periodic limb movements during sleep (15%) versus none in the control group. Children without sleep-disordered breathing or periodic limb movements during sleep had the lowest nocturnal sleep efficiency and total sleep time. CONCLUSIONS: We conclude that children with ADHD demonstrate objective daytime somnolence, which may explain the beneficial effects of treatment with stimulant medications. Primary sleep disorders, especially sleep-disordered breathing and periodic limb movement disorder, should be looked for in children with ADHD.     

Tobacco use amongst high school students in the Czech Republic

OBJECTIVE: We were interested in the prevalence of smoking amongst teen-age students, its possible causes, and their understanding of its associated health risks. METHODS: We constructed a questionnaire that was responded to by a total of 419 students from 5 high schools in Prague, Czech Republic. Students were classified as non-smokers, mild (1-10 cigarettes daily), moderate (11-20 cigarettes daily), and severe smokers (>20 cigarettes daily). The survey also contained questions about passive smoking, motivation for smoking, the understanding of its associated health risks, alcohol consumption, and drugs. RESULTS: We found that amongst 16-20 years old high school students there are 37.5% smokers (38.0% men, and 37.0% women). The majority are mild smokers (82.3%), 15.8% moderate smokers and 1.9% heavy smokers. 29.0% of non-smokers reported passive smoking; i.e. that 65.7% of students are exposed to harmful effect of tobacco smoke. The average onset of smoking is at 14 years of age. The youngest smoker started smoking at the age of 5 years. Parents of 52.0% of students smoke (69.4% of smokers and 41.6% of non-smokers). Most of students know about the risk of lung cancer and cardiovascular diseases (86-99%). CONCLUSIONS: The prevalence of active and passive smoking among high school students is high. Parents smoking is significantly more frequent in teen-age smokers than in non-smokers. We consider the "teen-age" population together with their parents to be the key target for a successful antismoking campaign.     

Subdivision of essential tremor patients according to physiologic characteristics

OBJECTIVE: To test the effect of different forearm postures on tremor characteristics. We hypothesized that changes in tremor characteristics in relation to posture can subclassify essential tremor (ET) patients. METHODS: Fourteen ET patients were tested while seated and holding a full cup in three well-defined arm postures: 15 cm above the armrest, elbow at 90 degrees flexion and when the cup was near the mouth. Hand movements were recorded using a triaxial accelerometer. Concomitantly, we recorded surface electromyogram (EMG) signals from the wrist extensor muscles. Hand acceleration and the primary tremor frequency from the power spectrum were calculated for each posture in two independent trials. The coherence at the primary tremor frequency between the EMG and the accelerometry signals was calculated. RESULTS: ET patients could be classified into two groups: ET-1 (nine patients) had position-dependent peak frequencies while ET-2 (five patients) had position-independent peak frequencies. The latter group had significantly higher coherencies between EMG and accelerometry of tremor and insignificantly higher tremor amplitudes compared with ET-1. In both groups tremor amplitude increased when the hand was near the mouth. CONCLUSION: The results suggest that ET patients can be classified based on the position dependence of frequency and other physiologic properties.     

Shabbes burn,a burn that occurs solely among Jewish orthodox children; due to accidental shower from overhead water heaters

From January 1990 to January 2000, 35 children were treated in our department for Shabbes burn, a unique scald burn that occurred mainly among orthodox Jews during the Sabbath. A retrospective review was conducted to determine the extent of the problem, to understand the burn mechanism and to suggest a prevention program. A shower of hot water from the Sabbath heater is the cause of this burn. Among the Shabbes burn cases, 27 patients were female (77%) and 17 children (48%) were between 3 and 6 years old. It is suggested that this is a common burn that occurs among orthodox Jewish families and affects mainly females. Education programs using the media directed to the Jewish orthodox population have been conducted, this combined with redesigned of the heater, have reduced significantly the incidence of the burn as seen in our institute. However, even though efforts have been supported widely, there remains a need for educational and governmental regulations on a national level. This could aid orthodox Jews not only in Israel but globally, as well.     

Regulatory disorders in Israeli infants: epidemiologic perspective

The concept of regulatory disorders has been clinically defined. However, epidemiologic validity has not yet been investigated. Children between the ages of 6 and 36 months (N = 450) were included in the study. Two age groups were analyzed separately: 6 to 17 months (53%) and 18 to 36 months (47%). A specially designed questionnaire in Arabic and Hebrew pertaining to the physiologic and behavioral aspects of regulatory disorders was administered at the mother and child health clinics in northern Israel. It was established in the present study that a minimum of four regulatory items should be reported for the diagnosis of a regulatory disorder, as perceived by parents. Factor analysis revealed 6 and 10 different aggregates of regulatory items in the young and older age groups, respectively. The general prevalence of regulatory disorder as defined in the present study was found to be 18%. Age, maternal education, and sex were found to be significantly related to the prevalence of regulatory disorders. No difference in the prevalence of regulatory disorders between Arab and Jewish infants was found. Further validations of the concept of regulatory disorder as well as devising appropriate measurements in well-designed studies are warranted.     

Probing biopolymers with the atomic force microscope: a review

This short review presents an overview of atomic force microscopy (AFM) of biopolymers and specific examples of some of the biopolymers that have been analyzed by AFM. These specific examples include extracellular polymeric substances on the surfaces of bacterial biofilms, condensed DNA, DNA constructs, and DNA-protein interactions. In addition, two examples are presented for AFM analyses of proteins: laminin flexing its arms in solution and neurofilaments entropically brushing away the space around themselves.