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Biomedical subjects

E L Baker

Publications and source records attributed to E L Baker.

At least 91 records · Page 5Linked to original sources

The role of occupational lead exposure in the genesis of psychiatric and behavioral disturbances.

In a prospective study of lead neurotoxicity, exposed foundry workers and referents were evaluated using a comprehensive set of neurobehavioral tests. Other performance indexes were used including a questionnaire, physical examination, and nerve conduction testing. Results show increased rates of depression, confusion, anger, fatigue and tension among workers with blood levels over 40 mcg/dl. Other aspects of neurobehavioral function, including verbal concept formation, memory, and visual/motor performance were also impaired. In view of the large number of individuals exposed to lead in their work, specific inquiries should be made of individuals with affectual complaints to clarify the nature of their work and workplace exposure to lead.

Adolescent↗

Computed tomography in the evaluation of Crohn disease.

The abdominal and pelvic computed tomographic examinations in 28 patients with Crohn disease were analyzed and correlated with conventional barium studies, sinograms, and surgical findings. Mucosal abnormalities such as aphthous lesions, pseudopolyps, and ulcerations were only imaged by conventional techniques. Computed tomography proved superior in demonstrating the mural, serosal, and mesenteric abnormalities such as bowel wall thickening (82%), fibrofatty proliferation of mesenteric fat (39%), mesenteric abscess (25%), inflammatory reaction of the mesentery (14%), and mesenteric lymphadenopathy (18%). Computed tomography was most useful clinically in defining the nature of mass effects, separation, or displacement of small bowel segments seen on small bowel series. Although conventional barium studies remain the initial diagnostic procedure in evaluating Crohn disease, computed tomography can be a useful adjunct in resolving difficult clinical and radiologic diagnostic problems.

Abscess↗

Monitoring neurotoxins in industry: development of a neurobehavioral test battery.

To facilitate the early detection of neurotoxicity in workers exposed to hazardous substances, we assembled a set of noninvasive neurobehavioral tests designed to assess memory, verbal concept formation, visuomotor performance, and mood. The tests were administered to an unexposed reference population and multivariate prediction equations were developed to control for effects of age, gender, and education. To define the briefest test set with appropriate sensitivity and specificity, we applied factor analysis and stepwise logistic regression to data from our referents and a group of lead-exposed workers. As a result, we have identified a comprehensive set of tests that can be administered in less than 40 minutes by trained medical technicians on plant premises and used to detect the early effects of neurotoxic substances on exposed workers. Guidelines for applying this technique to common work-place exposures, including other metals and organic solvents, are discussed.

Emotions↗

Incremental value of oblique chest radiographs in the diagnosis of asbestos-induced pleural disease.

To assess the value of oblique chest radiographs in the diagnosis of asbestos-related pleural disease, we identified 100 asbestos-exposed construction workers and provided separate interpretations of the postero-anterior (PA), left anterior oblique (LAO), and right anterior oblique (RAO) projections using the International Labour Office (ILO) system. We found that the LAO projection identified left-sided pleural thickening more effectively than the PA view and the RAO view improved diagnosis of right-sided disease comparably. Of 62 cases of bilateral pleural thickening, only 43 (68%) were diagnosed by the PA projection alone. The increased diagnostic efficiency of approximately 50% in identifying bilateral pleural thickening appears to justify the routine use of oblique chest films in screening asbestos-exposed populations. Since bilateral pleural thickening among asbestos-exposed workers is an indicator of significant asbestos exposure and increased risk of other asbestos-induced conditions, early detection of this abnormality can lead to interventions designed to reduce asbestos-related morbidity and mortality.

Adult↗

Paraoccupational exposure to mixed solvents.

Exposure to solvent vapors resulted in a sensory neuropathy and mild encephalopathy in a 44-yr-old female cook. The route of exposure was unusual: a ventilation system cross-connection between her restaurant and an adjacent upholstery shop. Possible "paraoccupational" exposures should be sought in cases of neurologic or other unexplained symptoms possibly caused by toxic substances. The role of solvent mixtures in the genesis of nervous system disorders is reviewed.

Adult↗

Follow-up studies of workers with bladder neuropathy caused by exposure to dimethylaminopropionitrile.

Following a 1978 outbreak of bladder neuropathy among workers exposed to dimethyl-aminopropionitrile (DMAPN), follow-up studies were performed 2 a after the original epidemic to evaluate the persistence of symptoms among a small group of initially affected workers. Although the overall prevalence of urologic and neurological symptoms fell for the 11 persons interviewed, significantly high rates of persistent symptoms were seen. Of particular concern was the increase in the prevalence of symptoms of sexual dysfunction. Physical examination identified one individual with sensorimotor neuropathy which was initially detected 2 a earlier. Three individuals who had similar neuropathic findings in 1978 were normal 2 a later. Objective neurophysiological and urologic testing revealed evidence of persistent abnormalities in several workers, but most of the objective findings had improved over the 2-a period. The follow-up of residual effects of occupational exposure to neurotoxic substances is essential to the understanding of the course of occupational illnesses.

Adult↗

Occupational lead exposure, nephropathy, and renal cancer.

A 48-year-old lead worker was found to have a cystic renal carcinoma during an evaluation of his occupational lead poisoning. Clinical studies showed elevated blood lead levels, impaired urinary concentrating ability, and reduced creatinine clearance. Histologic and electron microscopic studies showed this cystic tumor to be similar to renal carcinomas observed in animals with prolonged lead exposure. Lead content of the tumor was elevated (2.49 micrograms/gm) in comparison with adjacent renal tissue and with normal adult levels. In light of previous animal studies, this case adds increased evidence to the concern over the carcinogenic potential of prolonged lead exposure.

Adenocarcinoma↗

Neuropsychological effects of industrial toxins: a review.

Quantitative assessment of nervous system function is essential in characterizing the nature and extent of impairment in individuals experiencing symptoms following workplace exposure. In recent years, the application of standardized neuropsychological tests to the evaluation of exposure to toxic industrial substances has significantly increased the understanding of the effects of these compounds. Within this review, the specific toxic neuropsychological effects of lead, carbon disulfide, trichloroethylene, perchloroethylene, mercury, styrene, and pesticides are discussed in detail. These discussions draw on our clinical experience with patients exposed to these substances as well as material from the medical literature. Factors affecting the utilization of these tests in occupational settings are also considered.

Carbon Disulfide↗

Metabolic consequences of exposure to polychlorinated biphenyls (PCB) in sewage sludge.

Polychlorinated biphenyls (PCB) were discovered in sewage sludge used for fertilizer in Bloomington, Indiana. The PCB had been discharged into the municipal sewage system by an electrical capacitor manufacturing plant. To study the epidemiology and metabolic consequences of PCB exposure an epidemiologic and clinical survey was conducted. Mean serum PCB levels were 17.4 ppb in 89 sludge users, 75.1 ppb in 18 workers with occupational exposure to PCB, 33.6 ppb in 19 members of those workers' families, and 24.4 ppb in 22 community residents without unusual exposure to PCB. In sludge users PCB levels were associated positively with per cent performance of garden care (p = 0.035) and negatively with wearing gloves while gardening (p = 0.021), but were not significantly associated with the amount of sludge used or the duration of exposure. In no groups were chloracne or systemic symptoms of PCB toxicity noted, nor were significant correlations found between PCB levels and tests of hematologic, hepatic, or renal function. Plasma triglyceride levels increased significantly with serum PCB concentrations in both alcohol drinkers and nondrinkers (r = 0.541, n = 36, p < 0.001 for nondrinkers). These data indicate that PCB may alter lipid metabolism at levels of exposure and bioaccumulation insufficient to produce overt symptoms.

Agriculture↗

Group treatment of single males with erectile dysfunction.

Nine men with chronic erectile dysfunction (three primary, six secondary) who had no regular sexual partner were treated in two 12-session all-male psychoeducational therapy groups. Treatment intervention addressed specific factors which inhibited adequate sexual function with a focus on coping skills to overcome those factors. Pre, post, and follow-up behavioral self-report data and responses on a goal attainment scale questionnaire indicated that the treatment groups were successful for five men with secondary and one man with primary erectile dysfunction. Subjective report and pre- and posttreatment fantasy productions to TAT cards for the first group indicated that all men significantly improved their attitudes about sexuality and their sexual self-concept. The results suggest that this is a viable, cost-effective treatment for secondary erectile dysfunction, but not for primary erectile dysfunction unless supplementary individual therapy is provided.

Adaptation, Psychological↗

Occupational lead poisoning in the United States: clinical and biochemical findings related to blood lead levels.

Dose-response relationships between blood lead levels and toxic effects have been evaluated in 160 lead workers in two smelters and a chemicals plant. Blood lead levels ranged from 0.77 to 13.51 mumol/litre (16-280 microgram/dl). Clinical evidence of toxic exposure was found in 70 workers (44%), including colic in 33, wrist or ankle extensor muscle weakness in 12, anaemia (Hgb less than 8.69 mumol/litre (Hb/4) or 14.0 gm/dl) in 27, elevated blood urea nitrogen (greater than or equal to 7.14 mmol/litre or 20 mg/dl) in 28, and possible encephalopathy in two. No toxicity was detected at blood lead levels below 1.93 mumol/litre (40 microgram/dl). However, 13% of workers with blood lead levels of 1.93 to 3.81 mumol/litre (40-79 microgram/dl) had extensor muscle weakness or gastrointestinal symptoms. Anaemia was found in 5% of workers with lead levels of 1.93-2.85 mumol/litre (40-59 microgram/dl), in 14% with levels of 2.90 to 3.81 mumol/litre (60-79 microgram/dl), and in 36% with levels greater than or equal to 3.86 mumol/litre (80 microgram/dl). Elevated blood urea nitrogen occurred in long-term lead workers. All but three workers with increased blood urea nitrogen had at least four years occupational lead exposure, and nine had received oral chelation; eight of this group had reduced creatinine clearance, and eight had decreased renal concentrating ability. These data support the establishment of a permissible biological limit for blood lead at a level between 1.93 and 2.90 mumol/litre (40-60 microgram/dl).

Air Pollutants, Occupational↗

Cut flowers: a potential pesticide hazard.

Following reports of ten cases of possible organophosphate pesticide poisoning in florists exposed to pesticide residues on cut flowers, we conducted a prospective random-sample survey to determine residual pesticide levels on flowers imported into the United States via Miami, Florida. A sample of all flowers imported into Miami on three days in January 1977 showed that 18 (17.7 per cent) of 105 lots contained pesticide residue levels greater than 5 ppm, and that three lots had levels greater than 400 ppm. Azodrin (monocrotophos) was the most important contaminant with levels of 7.7--4,750 ppm detected in nine lots. We examined 20 quarantine workers in Miami and 12 commercial florists exposed to contaminated flowers. Occasional nonspecific symptoms compatible with possible organophosphate exposure were noted, but we found no abnormalities in plasma or red blood cell cholinesterase levels. This study documents a previously unrecognized potential source of occupational pesticide exposure and suggests that safety standards should be set for residue levels on cut flowers.

Adult↗