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Biomedical subjects

N Mantel

Publications and source records attributed to N Mantel.

At least 19 recordsLinked to original sources
PubMed1991

Mainstream and environmental tobacco smoke.

Environmental tobacco smoke (ETS) is derived from cigarette smoldering and active smoker exhalation. Its composition displays broad quantitative differences and redistributions between gas and respirable suspended particulate (RSP) phases when compared with the mainstream smoke (MSS) that smokers puff. This is because of different generation conditions and because ETS is diluted and ages vastly more than MSS. Such differences prevent a direct comparison of MSS and ETS and their biologic activities. However, even assuming similarities on an equal mass basis, ETS-RSP inhaled doses are estimated to be between 10,000- and 100,000-fold less than estimated average MSS-RSP doses for active smokers. Differences in effective gas phase doses are expected to be of similar magnitude. Thus the average person exposed to ETS would retain an annual dose analogous to the active MSS smoking of considerably less than one cigarette dispersed over a 1-year period. By contrast, consistent epidemiologic data indicate that active smoking of some 4-5 cigarettes per day may not be associated with a significantly increased risk of lung cancer. Similar indications also obtain for cardiovascular and respiratory diseases. Since average doses of ETS to nonsmoking subjects in epidemiologic studies are several thousand times less than this reported intake level, the marginal relative risks of lung cancer and other diseases attributed to ETS in some epidemiologic studies are likely to be statistical artifacts, derived from unaccounted confounders and unavoidable bias.

Animals↗
PubMed1990

Patterns of acquiring parkinsonism-dementia complex on Guam. 1944 through 1985.

For 1944 through 1985, documented clinical descriptions compatible with a diagnosis of parkinsonism-dementia complex were found in 363 Chamorros (including mixed Chamorros) and three Filipino immigrants who had lived on Guam before onset. Downward trends in age-adjusted incidence rates and upward trends in age at onset were seen for Chamorros of both sexes. Since 1980, new cases have occurred only among persons over 50 years of age, whereas a younger age at onset had been noted in the past. Evidence suggests that the length of the latent period varied widely (up to decades) and increased with time, the risk of acquiring parkinsonism-dementia complex had declined since the late 1950s, and the critical age of exposure to an unknown factor in the environment on Guam appears to have been during adolescence or adulthood.

Adult↗
PubMed1990

Geographic patterns of parkinsonism-dementia complex on Guam. 1956 through 1985.

Average annual age-adjusted incidence rates of parkinsonism-dementia complex were obtained for the 19 election districts of Guam from 1956 through 1985. The highest rates were found in the southern and central districts, and the lowest rates were found in the northern and western districts. Geographic and temporal patterns of incidence were associated with socioeconomic status but not with geochemical factors. The risk of parkinsonism-dementia complex in susceptible sibships was much higher than that in the general population--even in districts with the highest incidence rates, but especially in districts with the lowest incidence rates. Our evidence tends to support the hypothesis that multiple factors linked to cycad use play an important role in the cause of PDC. Hypotheses related to metal exposure and simple genetic factors were unsatisfactory explanations for the epidemiologic patterns observed.

Dementia↗
PubMed1988

An analysis of two recent epidemiologic reports in the New England Journal of Medicine associating breast cancer in women with moderate alcohol consumption.

Two cohort studies showed an association between moderate alcohol consumption and breast cancer, with an apparent relative risk of 1.50. Drinkers and nondrinkers already differed in important ways at the initiation of these two studies, precluding a causal interpretation of the associations found. Women in need of the relaxing effect of alcohol may indeed be the group at higher risk for breast cancer. Inasmuch as the studies did not inquire into other cancers, morbidities, mortalities, or total mortality, they leave open the possibility that, on balance, moderate alcohol consumption is beneficial.

Alcohol Drinking↗
PubMed1988

Friedreich's disease: survival analysis in an Italian population.

This investigation is the first population-based study of survival in Friedreich's disease (FD). All cases of FD diagnosed between 1945 through 1984 among residents of a defined area of northwestern Italy were ascertained (N = 58). These patients were followed to death or to December 31, 1984 (whichever came first) to determine the patterns of survival. The 10-, 20-, and 30-year survival rates were respectively 96%, 80%, and 61%, suggesting a better prognosis than previously reported. Survival of FD patients was poorer than expected from the general population. Survival for males was poorer than for females even after adjustment for expected survival. Age of onset was not a significant prognostic factor. Survival for patients diagnosed in 1960 or later was better than for those diagnosed before 1960; however, the difference was not statistically significant.

Adolescent↗
PubMed1986

Clinical laboratory manifestations of exposure to dioxin in children. A six-year study of the effects of an environmental disaster near Seveso, Italy.

Following a major environmental accident near Seveso, Italy, on July 10, 1976, we attempted to determine if the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) released into the atmosphere had any effect on the liver function and lipid metabolism of exposed children. From July 1976 to June 1982, we analyzed the results of more than 4500 laboratory tests (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, cholesterol, and triglycerides in plasma and delta-aminolevulinic acid in urine) in a population of about 1500 children aged 6 to 10 years at the moment of the accident. The children exposed to the highest concentration of TCDD showed alterations in serum gamma-glutamyltransferase and alanine aminotransferase activity compared with the control group. These differences were restricted to values inside limits set from the lower end of the normal range to slightly above it. The observed abnormalities were slight and disappeared with time.

Accidents, Occupational↗
PubMed1986

Cytomorphologic evaluation of the neoplastic potential of 28 cell culture lines by a panel of diagnostic cytopathologists.

A panel of 7 diagnostic cytopathologists, i.e., physicians trained to diagnose the malignant potential of human cells in Papanicolaou-stained smears, was asked to evaluate two sets of microscope slides of stained coverslip preparations of 28 cell culture lines, 15 of which were neoplastic. Slide Set I consisted of 13 pairs of cell lines, one member of each pair being nontumorigenic and the other tumorigenic; the lines were of mouse (9 pairs), rat (3 pairs), and human (1 pair) origin. Slide Set II contained 4 human lines: one lung cancer, one melanoma, and two fibroblast lines. Of a total of 114 diagnostic decisions by the panel, 88 were correct (66/86, 77%) in choosing which member of a pair was neoplastic and 22 were correct (22/28, 79%) in choosing whether a given individual human line was or was not neoplastic. Two members of the panel were correct more frequently, with 16/17 (94%) correct diagnoses, each. Five nuclear morphologic criteria of malignancy used by cytopathologists were prominent in the tumorigenic lines: altered chromatin pattern characterized by increasing size of chromatin granules and chromatin clumping, sharp angularity of large nucleolar and/or chromocenter borders with spicule formation (pointed projection), irregular parachromatin clearing (increase in the clarity of the clear spaces between chromatin threads, granules and clumps), uneven thickness of chromatin at the nuclear border, and variability in nuclear size and shape from cell to cell. These markers of neoplastic transformation, when added to those previously reported, should increase overall accuracy in the diagnosis of neoplastic transformation of mammalian cells in culture.

Animals↗