In vivo and in vitro percutaneous absorption and skin decontamination of arsenic from water and soil

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental pollutants. The major resident site for these PCBs is the soil, and human skin is frequently in contact with soil. Our objective was to determine the percutaneous absorption of the PCBs Aroclor 1242 and Aroclor 1254 from soil. PCB-contaminated soil was prepared at levels of 44 ppm Aroclor 1242 and 23 ppm Aroclor 1254. PCB concentrations on skin were 1.75 micrograms/cm2 for Aroclor 1242 and 0.91 microgram/cm2 for Aroclor 1254. In vivo percutaneous absorption in the rhesus monkey was determined by urinary and fecal [14C]-PCB excretion for a 5-wk period following topical dosing. Absorption of Aroclor 1242 was determined in vitro with human skin for comparative purposes. In vivo in the rhesus monkey the percutaneous absorption of Aroclor 1242 was 13.8 +/- 2.7 (SD)% of the dose and the absorption of Aroclor 1254 was 14.1 +/- 1.0%. These absorption amounts are similar to the absorption of Aroclor 1242 and 1254 from other vehicles (mineral oil, trichlorobenzene, acetone). With in vitro percutaneous absorption through human skin, most of the Aroclor 1242 and Aroclor 1254 resided in the skin and the amounts were dependent upon dosing vehicle (water > mineral oil > soil). Both PCBs readily partitioned from water into soil and human powdered stratum corneum. By difference the partitioning favored both PCBs going from soil into stratum corneum. These data emphasize the role of soil in percutaneous absorption and provide information for appropriate risk assessment.     

Comorbid survival among elderly male participants of the Canada health survey: relevance to prostate cancer screening and treatment

This study assessed the survival of a nationally representative sample of older Canadian men, taking into account common comorbid conditions. Mortality follow-up between 1978 and 1989 was conducted for male participants of the Canada Health Survey who were at least 60 years of age at baseline. The proportional hazards model and life table methods were used to examine survival by comorbidity status. Comorbid conditions examined included history of stroke and/or heart disease, high blood pressure, chronic bronchitis or emphysema, diabetes and smoking status, but excluded cancer because of small numbers. For those subjects aged 80 and older, comorbidity was not a significant predictor of survival. A large portion of men between the ages of 60 and 79, even those with pre-existing comorbid conditions, survived at least 10 years after interview. In a clinical setting, more detailed information on comorbid conditions can be obtained to better estimate long-term survival. Notwithstanding, our findings may have implications for the administration of population-based health interventions (e.g. the use of prostate-specific antigen [PSA] blood tests for the early detection of prostate cancer). In particular, our results suggest that there may be little benefit in restricting access to PSA screening based on survival probability in men under age 80.     

Femoropopliteal angioplasty in patients with claudication: primary and secondary patency in 140 limbs with 1-3-year follow-up

PURPOSE: To determine the usefulness of percutaneous transluminal angioplasty in the femoropopliteal arteries in patients with claudication. MATERIALS AND METHODS: In a prospective study of 106 claudicants (71 men and 35 women, aged 41-90 years [mean, 67 years]), a total of 208 lesions in 140 limbs were treated. The patients were followed up for 12-36 months. The patency rates were based on determination of the ankle-brachial index. RESULTS: The hemodynamic success rate for all the treated limbs was 89%, 99% for femoropopliteal stenoses (n = 71) and 80% for femoropopliteal occlusions (n = 69). In multiple logistic regression analysis, a smaller number of diseased vessels (one to two vs three to seven) and milder lesion severity (stenosis vs occlusion) correlated favorably with early success. Survival analysis with the Kaplan-Meier method according to established criteria revealed 1-, 2-, and 3-year primary patency rates of 47% (27 of 57 limbs), 41% (14 of 34 limbs), and 43% (three of seven limbs), respectively. CONCLUSION: In selected cases, good primary success and acceptable long-term results can be achieved with femoropopliteal angioplasty in claudicants.     

Patch testing in systemic drug eruptions

CrossLaps peptide [Glu-Lys-Ala-His-Asp-Gly-Gly-Arg], a part of the C-telopeptide of the alpha 1-chain of type I collagen of bone, is a recently developed biochemical marker of bone turnover. In this study, the clinical utility of measurement of urinary CrossLaps was investigated in eleven premenopausal women who received a gonadotropin-releasing hormone (GnRH) agonist for 6 months for treatment of adenomyosis (n = 1) or leiomyomas (n = 10). Along with urinary CrossLaps, the levels of various biochemical markers, and serum estradiol, calcitonin and intact parathyroid hormone (i-PTH) were measured, and lumbar spine bone mineral density (BMD) was also monitored before, during, and at the end of the course of GnRH agonist therapy. Apart from CrossLaps, markers of bone resorption tested were urinary pyridinoline, deoxypyridinoline and hydroxyproline. Markers of bone formation tested were serum osteocalcin and bone-specific alkaline phosphatase (B-ALP). Serum estradiol levels decreased to undetectable levels at 2 months of GnRH agonist therapy. The values for all biochemical markers increased significantly throughout the therapy. The degree of an increase in CrossLaps levels was greater than that in all other markers. Mean lumbar spine (L2-L4) BMD was decreased by 7.2% at 6 months of treatment. The percent change in BMD at 6 months of treatment correlated inversely with the percent change in CrossLaps levels from the baseline to 1, 2, and 5 months of treatment. These results indicate that measurement of urinary CrossLaps might be a useful tool to predict the risk of bone loss caused by hypoestrogenism including GnRH agonist therapy.     

Electromyographic temporal analysis of gait: hemiplegic locomotion

The telemetered electromyographic (EMG) activity of quadriceps, hamstrings, triceps surae and pretibial muscles on the affected side of 20 adult hemiplegic subjects was examined during locomotion. The subjects ranged in age from 29 to 68 years (mean, 52.1). Duration of the lesions ranged from 1 month to 8 years: in 11 subjects the duration of the lesions ranged from 1 to 9 months (mean, 4.9 months), and in the remaining 9 subjects from 1 to 8 years (mean, 4 years 2 months). Shoes with five microswitches, two in the heel and three in the sole, were used to correlate the EMG activity with eight specific components of the gait cycle. The results of the study showed a loss of the phasic pattern associated with normal locomotion. The hemiplegic subjects showed the greatest activity in the period of midstance. Expressed as a percentage of the total cycle, the mean stance time of the paretic lower limb was 67% and the mean swing time was 33%. The unaffected lower limb showed a stance phase of 80% and a swing phase of 20%.     

Effect of burn injury on glucose turnover in guinea pigs

The Reflomat System for rapid estimation of plasma or blood glucose concentration has been evaluated. The System gave a linear response throughout its analytical range and the recovery of glucose added to glucose-free plasma was 97-105%. Addition of sodium fluoride to plasma produced a 7-15% reduction in the estimated glucose concentration. Plasma glucose concentration estimated with the Reflomat agreed closely with results of a glucose oxidase and a hexokinase based method, and blood glucose concentration measured with the Reflomat agreed well with results of a glucose oxidase method.     

Biochemical studies on the H-2K antigens of the MHC mutants bm3 and bm11

Biochemical analyses of the H-2K-gene products of the C57BL/6 mutant strains, bm3 and bm11, have been carried out in order to characterize the structural relationships among these antigens. From comparative tryptic peptide mapping of cyanogen bromide fragments from the mutant and parent Kb glycoproteins and from preliminary amino-acid sequence analyses, a number of discrete differences have been discerned. Two sites of difference at amino residues 77 and 89 in the Kbm3 glycoprotein are noted relative to Kb. An alteration at residue 77 similar or identical to that seen in Kbm3 is present in the K antigen of the bm11 mutant. Because our techniques sample only 75 to 80 percent of the extracellular portion of H-2Kb, other undetected changes are possible. However, our present findings are most consistent with the conclusion that only very limited differences exist between mutant and parent molecules. Further, taken together with CML (cell-mediated-lymphocytotoxicity) reaction patterns (Melief et al. 1980), the biochemical data support the hypothesis that the proposed structural alterations in the Kb mutant glycoproteins are directly related to their observed immunological specificity.