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Biomedical subjects

J C Harris

Publications and source records attributed to J C Harris.

At least 55 records · Page 3Linked to original sources
PubMed1984

Hyperlexia in infantile autism.

Twenty boys meeting the current DSM III criteria for infantile autism at the time of diagnosis were found to be hyperlexic in childhood and have been followed up for 7-17 years. The most striking feature of the group was the compulsion to decode written material without comprehension of its meaning, and this constituted a behavioral phenotype for this population. On word recognition tests such as the WRAT, they scored significantly higher than would be predicted on the basis of intelligence but demonstrated severe reading retardation on tests of reading comprehension such as the Gates-McGinitie. Major differences in intelligence were detected, ranging from severe mental retardation to very superior intelligence. Major differences in verbal and nonverbal abilities were also noted. Many were found to have unusually good memory, both visual and auditory, and the majority possessed an excellent stored vocabulary that could be used with written words despite the poverty of their expressive language. It is suggested that the presence of hyperlexia may identify a subgroup of autistic children.

Adolescent↗
PubMed1983

The effect of nitrofen [4-(2,4-dichlorophenoxy)nitrobenzene] on the reproductive performance of male rats.

Technical grade nitrofen was fed to 4 groups (25/group) of male Sprague-Dawley rats for 13 weeks at dietary concentrations of 0, 100, 500, or 2500 ppm. Untreated female rats of the same age and strain were mated with treated males and fertility, gestation, and lactation indices were monitored. After mating, males were bled for clinical chemistry and hematology analyses, killed, and necropsied; organ weights were recorded, and liver, testes, and kidneys evaluated histopathologically. Offspring were observed for 35 days to determine general health and viability. At 2500 ppm, body weights of paternal animals were reduced throughout the dosing period. No hematologic abnormalities were seen. Statistically significant changes noted in clinical chemistry parameters included increased total protein, albumin, globulin, and cholesterol and decreased glucose. Testes, kidneys, and liver weights were increased at 500 and 2500 ppm, but histologic changes were limited to the liver with hypertrophy and cytoplasmic basophilia of centrilobular hepatocytes occurring at 500 and 2500 ppm. There were no effects on fertility, gestation, litter size, weight, or sex ratio in any group. Offspring health and survival to day 35 was unaffected. Based on the parameters examined, the no-observed effect level (NOEL) for male rats fed nitrofen for 13 weeks was 100 ppm. Male reproductive performance was not affected at dietary concentrations up to and including 2500 ppm.

Animals↗
PubMed1981

Toxicology of urea formaldehyde and polyurethane foam insulation.

Two types of foam insulation are in wide use. Urea formaldehyde foam is a relatively inexpensive, easily installed, and efficient insulation. Toxicity from this insulation is related to release of free formaldehyde into the home. Mild to incapacitating symptoms have been reported in occupants of urea formaldehyde-insulated homes. Airborne formaldehyde levels frequently have exceeded standards set for occupational exposure. The long-term consequences of such exposure are unknown. Because of publicity over the toxicity of urea formaldehyde foam, many physicians and patients have confused urea formaldehyde and polyurethane foam. Unlike urea formaldehyde, polyurethane foam is fully cured before construction. Toxicity occurs only during manufacture and curing. To date, there have been no reports to our knowledge of toxicity in occupants of polyurethane-insulated homes. However, toxicity caused by pyrolysis products may occur during combustion in homes insulated with either type of insulation. This report details 48 patients in whom complete medical data were obtained out of the first 100 patients contacting the Rocky Mountain Poison Center.

Construction Materials↗
PubMed1981

Comparative efficacy of injectable calcium and magnesium salts in the therapy of hydrofluoric acid burns.

Hydrofluoric acid (HF) causes severe skin burns which often progress in severity despite physiologic neutralization. The currently accepted therapy is the subcutaneous injection of calcium (Ca) gluconate to precipitate the residual free fluoride ion. Magnesium (Mg) also forms an insoluble fluoride salt and is less tissue irritating than Ca. This study compared the effects of subcutaneous injection of saline, Ca gluconate, Mg acetate (MgAc), and Mg sulfate (MgSO4) on lesions resulting from HF burns in rats. Burns treated with either Mg compound healed 3.7 +/- 1.7 days faster (p less than 0.05) developed less severe lesions (p less than 0.01) and exhibited left untreated or treated with saline. There was no difference in the incidence of infection between the study groups. The effects of burns treated with calcium were statistically similar to the control groups. This study suggests that Mg may be more effective than Ca in minimizing the duration, depth, and progression of dermal HF burns.

Animals↗
PubMed1979

Methemoglobinemia resulting from absorption of nitrates.

Three cases of toxic methemoglobinemia resulted from absorption of nitrate salts through burned skin areas. In addition to the unusual route of intoxication, this report emphasizes the occupational hazard of methemoglobinemia in workers exposed to nitrogen salts and the importance of rapid diagnosis and treatment. The diagnosis of methemoglobinemia should be suspected in any case of cyanosis refractory to oxygen therapy. Appropriate treatment should include oxygen, methylene blue, and exchange transfusion in clinically severe cases.

Accidents, Occupational↗
PubMed1977

Western equine encephalomyelitis in horses in the Northern Red River Valley, 1975.

In mid-July, 1975, western equine encephalomyelitis (WEE) virus was isolated from mosquitoes collected in flooded areas of eastern North Dakota and western Minnesota. Inasmuch as clinical manifestations of WEE are usually observed in horses before human cases of encephalitis are recognized, surveillance of equine disease was initiated. Sixty-one practicing veterinarians from the are under surveillance reported 281 cases of WEE in horses from June through September, with peak incidence in late July. The high percentage of sero-positive, clinically normal, unvaccinated horses in one region suggested that many horses had developed non-clinical infections. The efficacy of vaccines used by the practitioners appears to have been execllent, as none of the horses vaccinated before the epizootic became ill during the period of surveillance. It was concluded that data collected from routine surveillance of encephalomyelitis in horses could be used to predict epidemics of WEE.

Animals↗
PubMed1977

Hepatitis B in ward and clinical laboratory employees of a general hospital.

After a sharp increase in viral hepatitis cases, mostly type B, among the 2000 employees of a general hospital during three years, we conducted an investigation which consisted of obtaining data on employee cases and surveying many current employees. Of the 38 cases, 22 occurred in non-physician, ward employees. Of 189 current ward employees, 8% had antibody to hepatitis B surface antigen (anti-HBS) and 1% had hepatitis B surface antigen (HBSAg). Hepatitis B virus (HBV) seropositivity was highest for employees who worked closely with hemodialysis and renal transplant patients and for those who claimed that their ward was understaffed. Nine of the 38 cases occurred in clinical lab workers. Of 70 current lab employees, 17% were positive for anti-HBS and none for HBSAg. HBV seropositivity was highest for those working in the chemistry section (highest there among those performing blood-gas determinations and those working with the multi-channel autoanalyzers) and those who routinely got blood on their skin and clothes at work. All seropositive employees worked routinely with blood. These data support the hypotheses that many hospital employees contract hepatitis B from exposure to HBSAg-positive patients and many clinical laboratory employees contract it from exposure to HBV-contaminated blood.

Carrier State↗