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Biomedical subjects

J M Peters

Publications and source records attributed to J M Peters.

At least 181 records · Page 10Linked to original sources
PubMed1989

Histopathologic diagnosis and classification of prostate adenocarcinoma: biologic significance.

Early diagnosis and accurate, biologically meaningful classification of prostate neoplasia remain important goals. The relation of evolving clinicopathologic concepts of histologic appearances to potential tumor progression is a major advance in classification of prostatic neoplasia. The criteria for recognizing incidental or "occult" stage A-l adenocarcinomas remain problematic in diagnosis, and focal neoplasms with little or no propensity to progression must be differentiated from cancers with a high likelihood of aggressive behavior. Current histologic grading systems in classifying prostate adenocarcinoma accurately identify two cancer subsets: 1) focal well differentiated tumors which rarely progress, and 2) diffuse poorly differentiated tumors which invariably develop metastatic disease. Unfortunately, the majority of prostatic cancers are classified in the intermediate group in which the prognosis is variable and difficult to differentiate purely by histology. Our laboratory recently adapted image analysis of cellular DNA quantitation--a major improvement in accurately predicting tumor behavior, especially in the intermediate histologic grades. We and others have found that tumors with abnormal (aneuploid) DNA content are more likely to progress than neoplasms with normal (diploid) DNA content.

Adenocarcinoma↗
PubMed1989

Hypernatremia in breast-fed infants due to elevated breast milk sodium.

The author describes severe hypernatremic dehydration in a 12-day-old, breast-fed infant. The mother's breast milk sodium level at the 13th day of the infant's life was 47 mEq/L, more than three times normal value. At the 30th day, the mother's breast milk sodium level was 16 mEq/L, still more than twice the normal value. To the author's knowledge, this is the first time in a case of this type that the breast milk sodium value of the mother has been followed this late in the infant's life. Results are consistent with the hypothesis that delayed maturation of breast milk composition is of central importance in this condition. A search of the literature reveals that the mothers of these babies fit a clinically distinct profile. Elevated breast milk sodium with hypernatremic dehydration is a cause of significant morbidity in some breast-fed infants. The pathogenesis of this condition and the implications for its prevention are discussed.

Breast Feeding↗
PubMed1988

Tobacco, alcohol, diet, occupation, and carcinoma of the esophagus.

Information on occupation, smoking, food and beverage consumption, and medical history were compared between 275 incident cases of carcinoma of the esophagus and 275 neighborhood controls who were matched to the cases on age (within 5 years), race, and sex. Tobacco use, mainly cigarette smoking, was a significant risk factor for carcinoma of the esophagus. Ex-smokers of cigarettes showed a reduced risk relative to those who continued to smoke, and current smokers of two or more packs per day displayed a higher risk than those who smoked less. Alcohol consumption was another significant risk factor for carcinoma of the esophagus; there was a highly significant trend with average daily dose of ethanol. Relative to controls, cases also consumed significantly more fried bacon or ham, less fresh fruits and raw vegetables, and were more likely to prefer white than whole grain bread. Finally, there was a significant association between carcinoma of the esophagus and long-term occupational exposure to metal dust; this association was largely confined to the lower one-third section of the esophagus.

Alcohol Drinking↗
PubMed1988

Isocyanates and respiratory disease: current status.

This paper reviews the known respiratory effects of isocyanates. There is good evidence to indicate that isocyanates: cause chemical bronchitis/pneumonitis; are potent pulmonary sensitizers capable of causing "isocyanate asthma"; cause nonspecific airways disease, including chronic bronchitis; can induce a general asthmatic state; and can cause hypersensitivity pneumonitis. Similar dose-response relationships are seen for both acute and chronic effects. There are plants operating in which exposures are well controlled and in which no respiratory effects can be detected. Suggestions are provided for preplacement assessment and periodic surveillance for workers exposed to these compounds.

Air Pollutants, Occupational↗
PubMed1988

Myelogenous leukemia and electric blanket use.

In a case-control study of adult acute and chronic myelogenous leukemia in Los Angeles County, we tested the hypothesis that excess exposure to electromagnetic fields from electric blankets was associated with risk of leukemia. We did this by studying 116 cases of acute myelogenous leukemia (AML) and 108 cases of chronic myelogenous leukemia (CML) along with matched neighborhood controls. The cases and controls were queried as to electric blanket use and the risks computed. For AML the risk was 0.9 (95% CI 0.5-1.6) and for CML the risk was 0.8 (95% CI 0.4-1.6). Cases did not differ from controls by duration of use, year of first regular use, year since last use, or socioeconomic status. Our best estimates of exposure indicate that electric blanket use increases overall exposure to electric fields by less than 50% and magnetic fields by less than 100%. We conclude that there is no major leukemogenic risk associated with electric blanket use in Los Angeles County.

Adult↗
PubMed1988

Effect of the antihypertensive drug hydralazine on mineral metabolism in the rat.

The effects of hydralazine (HZ) on mineral metabolism was investigated in rats. Sprague-Dawley rats were fed HZ (0.1-4%, w/w) in three separate experiments: (1) a 2-week dose-response study; (2) a 2-month long-term feeding study; and (3) a pregnancy study. At the end of each experiment, tissues were removed and concentrations of Mn, Cu, Zn and Fe were measured. Results from the three experiments were similar. HZ had no effect on tissue Mn and Zn concentrations, while tissue Fe concentrations were lower and kidney Cu concentrations were higher in HZ-treated groups compared to controls. The effect of HZ on mineral metabolism may be, in part, responsible for some of its negative side effects.

Animals↗
PubMed1988

Adenocarcinoma of the stomach and exposure to occupational dust.

The authors studied 1,342 cases of adenocarcinoma of the stomach identified by a population-based cancer registry in Los Angeles County, California. The cases were males aged 20-64 years first diagnosed between 1972 and 1982. To determine whether exposure to occupational dust increased the risk of developing stomach cancer, occupational titles were rated for the likelihood of exposure to various kinds of dust. Men who worked in dusty jobs had a risk for developing stomach cancer 1.3 times that of unexposed men (95% confidence interval = 1.2-1.4). The association of exposure to dust with stomach cancer was stronger at higher levels of exposure. The risk was not uniform throughout the stomach: the highest risk (1.8 times that of unexposed men) was found for the antrum/pylorus. At that site, exposure to mineral dust carried the greatest risk for cancer (3.7 times the risk for unexposed men). The highest risks from dust exposure were observed in blacks. Risk was related to race, socioeconomic status, and immigrant status, but these factors did not entirely explain the association with dust exposure. The observed relation between dust exposure and stomach cancer is consistent with results of previous mortality and case-control studies of cancer in men who worked in dusty occupations. Ingested dust may be one factor in the etiology of adenocarcinoma of the stomach.

Adenocarcinoma↗
PubMed1987

Abnormalities of pulmonary function and pleural disease among titanium metal production workers.

The authors conducted a cross-sectional survey of respiratory disease among 209 titanium metal production workers. Work in areas where there was exposure to titanium tetrachloride and titanium dioxide particulates was associated with reductions in ventilatory capacity. Pleural disease (plaques and diffuse thickening) was present in the chest radiographs of 17% of the subjects and was associated with the duration of work in titanium manufacturing. It was also associated with past asbestos exposure. After control for asbestos exposure, it remained associated with titanium manufacturing. The findings are consistent with the hypothesis that titanium tetrachloride and titanium dioxide particulates may be associated with a reduction in ventilatory capacity and that the overall process of titanium manufacturing may be associated with unexpected pleural disease.

Adult↗
PubMed1987

Childhood leukemia and parents' occupational and home exposures.

A case-control study of children of ages 10 years and under in Los Angeles County was conducted to investigate the causes of leukemia. The mothers and fathers of acute leukemia cases and their individually matched controls were interviewed regarding specific occupational and home exposures as well as other potential risk factors associated with leukemia. Analysis of the information from the 123 matched pairs showed an increased risk of leukemia for children whose fathers had occupational exposure after the birth of the child to chlorinated solvents [odds ratio (OR) = 3.5, P = .01], spray paint (OR = 2.0, P = .02), dyes or pigments (OR = 4.5, P = .03), methyl ethyl ketone (CAS: 78-93-3; OR = 3.0, P = .05), and cutting oil (OR = 1.7, P = .05) or whose fathers were exposed during the mother's pregnancy with the child to spray paint (OR = 2.2, P = .03). For all of these, the risk associated with frequent use was greater than for infrequent use. There was an increased risk of leukemia for the child if the father worked in industries manufacturing transportation equipment (mostly aircraft) (OR = 2.5, P = .03) or machinery (OR = 3.0, P = .02). An increased risk was found for children whose parents used pesticides in the home (OR = 3.8, P = .004) or garden (OR = 6.5, P = .007) or who burned incense in the home (OR = 2.7, P = .007). The risk was greater for frequent use. Risk of leukemia was related to mothers' employment in personal service industries (OR = 2.7, P = .04) but not to specified occupational exposures. Risk related to fathers' exposure to chlorinated solvents, employment in the transportation equipment-manufacturing industry, and parents' exposure to household or garden pesticides and incense remains statistically significant after adjusting for the other significant findings.

Acute Disease↗
PubMed1987

Smoking as a risk factor in noise-induced hearing loss.

We studied the relationship between cigarette smoking and hearing loss among 2,348 noise-exposed white male participants in a hearing conservation program at an aerospace company. Comparisons of risk factors were based on two definitions of hearing loss. In the first, cases were defined as those subjects in the top third of the hearing loss distribution (at 3, 4, and 6 kHz) for their age category, and controls were those subjects in the lowest third of the distribution. The crude relative risks for smokers were significantly elevated (ever smoker: odds ratio = 1.27, p = .02; present smoker: odd ratio = 1.39, P = .002) compared with never smokers. Simultaneous evaluation of several risk factors using multiple logistic regression methods indicated that the effects of smoking, having a noisy hobby, and years worked at the plant were independent factors for hearing loss. Statistically significant trends in risk were observed for the number of pack-years of smoking (P = .007) and current packs per day consumption in present smokers (P = .009). In the second definition, hearing loss cases were defined according to National Institute for Occupational Safety and Health criteria for beginning impairment. By using multiple logistic regression, present smoking was a statistically significant independent predictor of impairment. These results suggest that smokers are at increased risk of noise-induced hearing loss.

Adolescent↗
PubMed1987

Excessive lead absorption resulting from exposure to lead naphthenate.

There are no reported studies of the relationship between exposure to lead naphthenate and lead absorption in humans. In an aluminum forging operation where lead naphthenate was sprayed without local ventilation, the mean concentration of lead in air was 96 micrograms/m3 with a range of 12-430 micrograms/m3. The 29 forge operators who worked in this area had a mean blood lead concentration of 63 micrograms/dl, which was statistically significantly (P less than .001) higher than the mean blood lead concentration of 17 micrograms/dl among the 103 unexposed workers. Similarly, the mean zinc protoporphyrin concentration among the forge operators was 265 micrograms/dl, which was statistically significantly (P less than .001) higher than the mean concentration of 26 microgram/dl among the unexposed workers. Nineteen workers, all of whom worked in the forge areas, had blood lead concentrations in excess of 60 micrograms/dl, with the highest concentration being 108 micrograms/dl. This is the first reported instance in which the use of lead naphthenate has been associated with increased lead absorption in humans.

Absorption↗
PubMed1986

Immunolocalization and partial characterization of a nucleolar autoantigen (PM-Scl) associated with polymyositis/scleroderma overlap syndromes.

Precipitating anti-PM-Scl antibodies are present in sera from patients with polymyositis, scleroderma, and polymyositis/scleroderma overlap syndromes. By indirect immunofluorescence microscopy, anti-PM-Scl antibodies stained the nucleolus in cells of different tissues and species, suggesting that the antigen is highly conserved. By electron microscopy, anti-PM-Scl antibodies reacted primarily with the granular component of the nucleolus. Drugs that inhibit rRNA synthesis had a marked effect on the expression of PM-Scl antigen. In actinomycin D-treated cells, immunofluorescence staining by anti-PM-Scl was significantly reduced with residual staining restricted to the granular regions of nucleoli. Treatment with 5,6-dichloro-beta-D-ribofuranosylbenzimidazole (DRB) also selectively reduced nucleolar staining. On a molecular level, anti-PM-Scl antibodies precipitated 11 polypeptides with molecular weights (Mr) ranging from 110,000 to 20,000. The Mr 80,000 and 20,000 polypeptides were phosphorylated. Evidence suggests that the PM-Scl antigen complex may be related to a preribosomal particle.

Animals↗
PubMed1986

Recent trends in mesothelioma incidence in the United States.

Mesothelioma incidence rates based on data from population-based cancer registries in New York State (exclusive of New York City), Los Angeles County, California, and the SEER Program of the National Cancer Institute were analyzed for trends, using original cancer registry diagnoses. Results indicate a significant increase in incidence during 1973-80 for pleural mesothelioma among white males older than 55 at time of diagnosis but not for other age-race-sex-site subgroups. A histopathologic review of New York State and Los Angeles County cases by two independent pathologists, expert in the diagnosis of mesothelioma, lowered the overall estimates but a significant upward trend remained. The observed trend does not appear to be related to changes in diagnostic practice. The results of a five-member panel of expert pathologists will be published in a separate methodology paper.

Adolescent↗
PubMed1986

Myocardial blood flow and glucose uptake after myocardial infarction.

Position emission tomography can picture the distribution of flow tracers as well as of metabolic substrates or analogs. Studies of the distribution of these tracers allow to infer information about regional myocardial clearance (flow X extraction) and substrate utilization. In a study of 32 patients after myocardial infarction, we have contrasted flow and substrate utilization to demonstrate ischemic but viable myocardium in the arterial territory of the infarct in a number of patients also specially after fibrinolytic reperfusion. Restoration of blood flow to the ischemic but viable myocardium through coronary bypass or dilatation improves flow from 56.3% to 84.2% of control and restores substrate utilization. In another group of 32 patients studied with the Strontium-82/Rubidium-82 generator, we have demonstrated perfusion changes both in the myocardial infarct area and at a distance. These changes predominate in patients with multiple vessel disease. Combined PET studies of flow and substrate utilization are new tools to study early intervention after myocardial infarction and to document the benefits of revascularization.

Aged↗