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Biomedical subjects

T H Ingalls

Publications and source records attributed to T H Ingalls.

At least 19 recordsLinked to original sources
PubMed1989

A case-control study of circulatory, malignant, and respiratory morbidity in carbon black workers in the United States.

The exposures to total dust of a group of carbon black workers with selected circulatory, malignant, and respiratory diseases were compared with the exposures of nonaffected, matched control workers. Exposure was calculated by combining ambient air measurements (mg/m3) for each job category with the months workers had spent in each job. The cumulative total dust exposure levels of the cases were comparable to those of the controls, with the exception of men who had diseases of the circulatory system and who had experienced significantly less exposure than had the matched control workers. The results of this study indicate that exposure to carbon black in the workplace does not increase the workers' risks of circulatory, malignant, or respiratory morbidity.

Carbon↗
PubMed1989

Clustering of multiple sclerosis in Galion, Ohio, 1982-1985.

Epidemiologic evidence indicates that the outbreak of 30-40 cases of multiple sclerosis and other demyelinating syndromes in Galion, Ohio, USA, during 1982-1985 was related to an excess concentration of heavy-metal wastes, especially of cadmium and chromium in sewage and river water. Both multiple sclerosis and myasthenia gravis were diagnosed by board-certified neurologists.

Amyotrophic Lateral Sclerosis↗
PubMed1988

A cross-sectional study of pulmonary function in carbon black workers in the United States.

Since a proportion of airborne carbon black particles is of respirable size, the possibility that it may affect pulmonary function was investigated in 913 employees of 6 carbon black producers in the United States. Exposure was estimated by combining the mean total dust exposures of each job category with the length of time workers had spent in each job, giving a measurement expressed in mg/m3.months. Pulmonary function was measured by spirometry. The major variables affecting pulmonary function were age and cigarette smoking. When the effects of age and smoking were controlled in an age-specific, two-way analysis of variance, no consistent effects of total dust exposure were detectable in these workers. This study provided no evidence that exposure to total dust under the conditions pertaining in the contemporary carbon black industry had detrimental effects on the pulmonary function of men employed in the production and handling of this product.

Adult↗
PubMed1986

Endemic clustering of multiple sclerosis in time and place, 1934-1984. Confirmation of a hypothesis.

The occurrence of multiple sclerosis in clustered groups of cases that are often related to others in time and place has been observed on several occasions in the last 50 years. Selected clusters are here reviewed in relation to suspected sources of heavy metal (mercury, lead) poisoning as background for the analysis of the 1983-1985 "outbreak" of 30-40 cases of multiple sclerosis in Key West, Florida. Evidence is presented that the time-place clustering resulted from environmental pollution stemming from a nearby dump pile of rocky debris. The probable mechanism is discussed.

Adult↗
PubMed1983

Epidemiology, etiology, and prevention of multiple sclerosis. Hypothesis and fact.

Slow, retrograde seepage of ionic mercury from root canal or Class V amalgam fillings inserted many years previously, recurrent caries and corrosion around filling edges, and the oxidizing effect of the purulent response may lead to multiple sclerosis in middle age. Epidemiologic studies of MS consistently reveal more neurological disease in the north, inferentially because there may be less caries and therefore fewer fillings done in the south. Clinical and epidemiologic data also suggest that a second heavy metal, lead, may operate almost interchangeably with mercury. Possibly, cases of unilateral MS derive from mercury-amalgam fillings in ipsolateral teeth, whereas the generalized disease may result from ingestion or inhalation of volatile mercury or exhaust fumes of lead additives to gasoline. The forensic and preventive-medical challenge is to identify, monitor, and resolve questions of hidden heavy metal hazards in a high technology society, especially those of lead and mercury. Further clinical-epidemiologic and basic science studies of heavy metal assays in whole blood, CNS tissues, packed cells, and serum are warranted. Prevention awaits further testing of the hypothesis and experience with substitute filling materials.

Climate↗
PubMed1976

Ovum aging and pH imbalance as a cause of chromosomal anomalies in the hamster.

Using female hamsters mated in estrus, we have produced triploid embryos as manifestations of pregnancy wastage by combining delays of 3 to 4 hours in ferilization with exposure of the animals to hypoxia. Among the triploid embryos only XXX and XXY karotypes occurred, indicating derivation from XX-containing ova. These findings have relevance to human reproduction.

Animals↗
PubMed1975

Chromosome mutations and pH disturbances.

Chromosomal anomalies, namely hypodiploidies, hyperdiploidies, and endoreduplications, developed in nearly 25% of metaphase plates of replicating human lymphocytes exposed in vitro to either acid (6.5 to 6.9) or alkaline (8.4 to 8.8) pH equilibriums. The G group was most susceptible to aneuploid formation. Mammalian mutations may develop as the result of a pH disturbance during cleavage of the fertilized zygote.

Aneuploidy↗