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J M Kranz

Publications and source records attributed to J M Kranz.

10 recordsLinked to original sources
PubMed1987

An introduction to the use of epidemiologic research methods in dairy science.

Many dairy scientists are not familiar with epidemiologic study designs and measures. The various designs (cross-sectional, case-control, cohort) are reviewed with special reference to their strengths and weaknesses. Epidemiologic measures (incidence and prevalence rates, relative risk, odds ratio, attributable fraction, and population attributable fraction) are defined, and their validity in the contexts of the different study designs is discussed. Incidence rate (risk of disease) is the number of new cases of a disease divided by the population at risk during a specified time period. Prevalence rate is the frequency of both new and old cases in a population at a specified point or period in time divided by the average population during that same period. Both incidence and duration of disease contribute to prevalence. Odds ratios and relative risks are measures of association (how much disease the exposed group experienced relative to the nonexposed group) and are used to assess the relative importance of risk factors. Attributable fraction is the proportion of the incidence in the exposed group that can be attributed to the specific exposure. Population attributuable fraction is the expected reduction in incidence in the whole population if the specific exposure were prevented. The attributable fractions are useful in planning preventive and herd health programs.

Animals↗
PubMed1984

Toxicologic studies associated with the agricultural use of municipal sewage sludge and health effects among sewage treatment plant workers.

The proposed use of municipal sewage sludges as soil amendments on agricultural land involves potential health risks. Sludges may contain toxic heavy metals, synthetic organics, and pathogens. Studies of animals inhabiting sludge-amended soils, or foraging on crops grown on such soils, have shown an increased deposition of cadmium and polychlorinated biphenyls in animal tissues, hepatic microsomal enzyme induction, altered blood profiles, appearance of mutagens in blood and excreta, and lowered feed intake, feed efficiency, and milk production. Epidemiologic evidence of possible adverse health effects among sewage plant workers exposed to aerosolized pathogens or synthetic organic vapors during wastewater treatment or land spreading of sludge is still inconclusive. Other possible deleterious environmental effects include pollution of groundwater and toxicity to birds consuming worms or insects inhabiting sludge-treated soils.

Agriculture↗
PubMed1983

Defining and measuring exposure in epidemiologic studies of potential zoonoses.

Articles suggesting the zoonotic potential of certain human diseases (eg, multiple sclerosis, rheumatoid arthritis, and leukemia) periodically appear in the literature and frequently receive considerable attention in the popular press. Although various epidemiologic study designs have been utilized to test these hypotheses, defining and accurately measuring animal exposure has been a problem common to most of these studies and in some instances has limited their usefulness. The relative strengths and limitations of the definitions and measurements used most commonly by investigators evaluating potential zoonoses are discussed. In addition, several recommendations for assessing animal exposure in future studies are made.

Animals↗
PubMed1975

An alternative to routine operative cholangiography.

The use of the Fogarty biliary balloon catheter has added to the safety of common duct exploration. Review of our own series seems to support this concept. With this adjunct adn a careful anatomic dissection of the biliary system, one can decide to do cholangiography or common duct exploration based on carefully considered clinical factors when stones are suspected. Perhaps neither need to be done in many instances. Without trying to question the virtures of operative cholangiography, we believe that it can be used selectively rather than routinely.

Catheterization↗