John E. Davies

Coffee Drinking and Death Due to Coronary Heart Disease

For a series of 649 patients who died of coronary heart disease within 24 hours of onset of symptoms, and an equal number of neighborhood controls, information was obtained on a large number of variables, including coffee consumption. An analysis using multivariate risk scores to control for all available variables yields a maximum likelihood estimate of the risk ratio associated with coffee drinking of 1.1 (95 per cent two-sided confidence limits, 0.8 to 1.6). The estimate of the risk ratio depends somewhat on the number and nature of variables controlled for in the analysis. Overall, our findings, limited to low-risk and middle-risk patients, suggest that the risk, if any, of death from coronary heart disease associated with coffee drinking is small.

Occupation and the high risk of lung cancer in Northeast Florida

A case‐control study involving interviews with 321 male patients with lung cancer and 434 controls, or their next of kin, was undertaken to identify reasons for the high lung cancer mortality along the northeast coast of Florida. In Duval county (Jacksonville), the age‐adjusted rate for lung cancer, 1970–1975, among white males was the highest of all urban counties in the United States. Increased risks on the order of 40–50% were associated with employment in the shipbuilding, construction, and lumber/wood industries, particularly among workers with reported exposures to asbestos or wood dust. Excess risks were also linked to fishing and forestry occupations, although the numbers of cases involved were small. Occupational factors did not appear to fully account for the area‐wide excess of lung cancer, but no evidence was found to implicate smoking habits, migration patterns, or diagnostic and reporting practices as factors responsible for the exceptional mortality rates.

Diagnostic and Therapeutic Problems of Parathion Poisonings

Abstract Because poisoning by parathion may simulate other more common diseases, its early diagnosis is not always easy. The ultimate outcome of such an intoxication is very largely dependent upon,...

Reversibility of the inhibitory effect of atrazine and lindane on cytosol 5 alpha-dihydrotestosterone receptor complex formation in rat prostate.

Once entering the bloodstream, most toxic substances, including pesticides, can reach organs involved in the reproductive system. They can cross the placenta, as well as the brain barrier, posing various risks to the reproductive processes. The organochlorine insecticide lindane and the s-triazine herbicide atrazine produce changes in hormone-dependent reactions in the rat hypothalamus, anterior pituitary, and prostate. Lindane also causes histological and biochemical alterations in the rat testis. In vivo treatment with atrazine produces a markedly inhibitory influence of 5{alpha}-dihydrotestosterone - receptor complex formation in rat prostate cytosol. Therefore, the aim of this study was to investigate whether such changes in the crucial step in the reproductive process are reversible. A parallel investigation using lindane was also undertaken.

Spontaneous abortion and human pesticide residues of DDT and DDE

published information regarding the transport characteristics of mammalian urinary bladder, particularly that of the newborn. This study is concerned with the transport characteristics of bladders removed from newborn subhuman primates (Macaca mulattu). The mothers were delivered by cesarean section between 141 and 147 days’ gestation (usual gestation 164 2 5 days). The neonate was killed with sodium pentobarbital within 5 hours of birth and the urinary bladder immediately excised and opened. After the bladder had been washed briefly in a buffered electrolyte 11 mM. glucose solution,2 it was mounted on specially designed chambers3 and bathed with the same solution. This experimental technique permits transmural electrical measurements and flux to be obtained while controlling electrolyte solution concentration, ambient temperature, oxygenation, and mixing.4 The unidirectional transmural sodium flux was determined with the use of Na?” (New England Nuclear Corp.) as a label. Seven individual newborn urinary bladders were examined for periods of 3 hours. In no instance was a transmural electrical potential difference found. Unidirectional mucosa-serosa and seroba-mucosa fluxes of Na are listed in Table I. There is no net Na flux. These findings ,:no net Na flux and no transmural potential difference) are compatible with passive transfer mechanisms dependent upon a concentration gradient as the driving force. They do not suggest the presence of a metabolically dependent active sodium pump in the primate newborn llrinary bladder.

The cardiotoxicity of eosinophils.

Although an association between high blood eosinophil counts and endomyocardial disease has been known for nearly a hundred years, the reasons for this were not understood. Brockington, Luzzatto and Osunkoya (1970) suggested that eosinophil leucocytes, in susceptible persons, by some unknown mechanisms, cause endomyocardial damage. Evidence to support this possibility has come from three sources: (1) Clinical studies have shown that very high blood eosinophil counts, from any cause, can be associated with endomyocardial disease, and in some patients it has been possible to show that eosinophilia preceded the onset of heart disease. (2) The development of heart disease has been associated with the presence of degranulated eosinophils in the blood and tissues, including damaged endomyocardium, and raised serum levels of eosinophil granule basic proteins have been found in many of these patients. (3) Low concentrations of eosinophil secretion products (which contain these eosinophil granule basic proteins) have been found to injure isolated heart cells in vitro. Studies with purified eosinophil granule basic proteins have shown that cardiac cell damage is the result of a specific toxic effect of eosinophil cationic protein on the plasma membrane and two enzyme complexes (pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase) involved in mitochondrial respiration. These results support the suggestion that under certain conditions, eosinophils may damage the heart, leading to endomyocardial disease, and they offer new approaches for the early diagnosis and treatment of endomyocardial disease both in temperate and tropical countries.

Changing Profile of Pesticide Poisoning

Since 1945, some 15,000 individual compounds and more than 35,000 different formulations have come into use as pesticides. During this period, as a result of the widespread use of these agents, and...

RENAL TUBULAR DYSFUNCTION AND AMINO ACID DISTURBANCES UNDER CONDITIONS OF PESTICIDE EXPOSURE

For the most part, knowledge of the biological effects of acute exposure to pesticides has been well documented. The same cannot truly be said with regard to the effects of chronic exposure; for this reason, increased emphasis on research in this area has been recommended bv several scientific bodies. To this end, the Community Pesticides Studies Program has been one of the research organizations developed and charged with the responsibility of answering some of the special questions in the field of chronic and long-term exposure. In Dade County, Florida, our community pesticide studies under the guidance of and in cooperation with the Florida State Board of Health have focused research activities on the highly exposed group. The assumption has been that, if there are any ill effects that are the result of long-term exposure to pesticides, these will be found most abundantly in the occupationally exposed pesticide worker. For the last two and one-half years, therefore, intensive clinical, enzymatic, metabolic, and biochemical evaluation of the pesticide worker has been continuing. Thus far, renal tubular and amino acid disturbances have been encountered in this study group. This paper seeks to present preliminary data on these functional abnormalities and speculates as to the possible cause of such changes.

OCCURRENCE, DIAGNOSIS, AND TREATMENT OF ORGANOPHOSPHATE PESTICIDE POISONING IN MAN

The purpose of this paper is to present a synthesis of a multidisciplined approach to the problem of organophosphate pesticide poisonings in man from the standpoint of its epidemiologic, diagnostic clinical, laboratory, and therapeutic aspects. It is not meant to be an exhaustive review of the literature, but to group together the salient features observed by investigators within a community faced with this problem. INCIDENCE

PESTICIDE MONITORING STUDIES. THE EPIDEMIOLOGIC AND TOXICOLOGIC POTENTIAL OF URINARY METABOLITES

Accurate expressions of human pesticide exposures and environmental contamination suffer from interpretative difficulties which stem from the use of biologic indices which are indirect and nonspecific measures of human exposure (cholinesterase inhibition). Environmental indices also lack precision due to analytical shortcomings. Our studies of the urinary pesticide metabolites have demonstrated that the alkyl phosphates are highly sensitive expressions of recent human exposure to the organophosphate group of pesticides. Urinary phenolic metabolites, when present as a component of these molecules, are sensitive indicators of recent individual organophosphate exposure. Urinary alkyl phosphates served as ideal diagnostic tools of acute pesticide poisonings and diethyl phosphate (DEP) concentrations greater than 0.4 ug/ml occurred with clinically significant parathion exposure.