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Biomedical subjects

W D Johnson

Publications and source records attributed to W D Johnson.

At least 181 records · Page 10Linked to original sources
PubMed1982

Employment patterns in males before and after myocardial revascularization surgery. A study of 2229 consecutive male patients followed for as long as 10 years.

Loss of productivity is a major concern among patients with heart disease. To assess the effect of surgery on this factor, we surveyed every living male patient of the surgeon authors operated on from January 1968 through March 1978 (96% follow-up) and compared their pre- and postoperative work status with the U.S. population as reported by the U.S. Bureau of Labor Statistics (USBLS). Comparisons were made on an age-for-age basis and adjustments were made for changes in national employment patterns from 1968-1978. Preoperatively, our younger patients had a 10% lower employment rate than the U.S. male population at large according to the USBLS. Postoperatively, many returned to work, but an equal number who worked preoperatively did not postoperatively. The ability to work full time with little or no limitation increased 20% after operation. The main reason for not working was physical disability, with doctor's advice a distance second. Older patients showed a trend of accelerated retirement after surgery. A few returned to work, but many more retired. The ability to work full-time without limitation increased 4%. Thirty percent of all older subjects cited a desire to relax as their main reason for not working. Compared with the early years of surgery, patients in later years were older and did not show as much preoperative disability. There was some evidence of a deterioration of the effects of surgery. Patients with severely impaired left ventricular function fared worse both pre- and postoperatively, but the improvement was the same as for patients with normal or moderately impaired left ventricular function.

Adult↗
PubMed1981

Long-term carcinogenicity and toxicity studies of patulin in the rat.

Patulin is a mycotoxin produced by a variety of Penicillium and Aspergillus species which are likely natural contaminants of various foods. The present study was conducted to determine the effects of lifetime administration of patulin in FDRL Wistar rats. Animals received patulin by gastric intubation three times per week at the level of 0.0, 0.1, 0.5 and 1.5 mg per kg body weight. The animals used in this lifetime study were derived from F0 parents exposed to equivalent levels of patulin for 4 weeks before mating, and throughout mating, gestation and lactation. Patulin treatment at 0.5 and 1.5 mg kg-1 to male rats caused a significant decrease in body weight gain in comparison to controls. Body weights of treated female rats were similar to that of control rats. No consistent significant differences among groups were noted in the hematology, clinical chemistry or urine analysis parameters measured during or at the termination of the study. Patulin administered to male and female rats at 1.5 mg kg-1 caused a significantly increased mortality rate as compared to respective control animals. The cause of death appeared to be increased pulmonary and laryngotracheal inflammation. No tumorigenic effect of patulin was observed.

Animals↗
PubMed1981

Hypertension and arteriolar sclerosis of the kidney, pancreas, adrenal gland, and liver.

Replicate slides of autopsy specimens (kidney, pancreas, adrenal glands, and liver) from 66 hospital patients who had lengthy outpatient records of their blood pressure levels were randomized and graded blindly for the severity of hypertensive fibroproliferative-mediodegeneration lesions of arterioles (arplasia). For all four tissues, the severity of lesions correlated significantly with the level of the blood pressure. Between blood pressure and lesions the correlation coefficient was significantly smaller (P Less Than 0.01) for liver and adrenal than for kidney. The correlation coefficient was also smaller for pancreas than for kidney, but the statistical significance of the difference (0.3 Greater Than P Greater Than 0.2) was not conclusive. The results tend to confirm the conclusions of the classic 1937 report of Moritz and Oldt, adding strength to their generalization that "Arteriolar sclerosis is the most common cause of chronic hypertension."

Adrenal Glands↗
PubMed1981

Patency and flow response in endarterectomized coronary arteries.

Ninety patients, operated on from May, 1978, through June, 1979, underwent coronary endarterectomy and early recatheterization. Patency of grafts to endarterectomized arteries was 103 of 118 (87.3%) and patency of conventional vein grafts in the same patients was 217 of 233 (93.1%). Myocardial blood flow using xenon 133 washout, at rest and with isoproterenol-induced stress, was measured in 7 normal coronary arteries, 28 conventional saphenous vein grafts, and 33 saphenous vein grafts to endarterectomized coronary arteries. The increase in myocardial blood flow, from rest to isoproterenol-induced stress, was comparable for the three groups. The endarterectomized group was divided further by separating out the 10 patients with heavy scarring or residual disease. The remaining patients had a flow response identical to those with conventional saphenous vein grafts. The rate of perioperative infarction in patients receiving endarterectomy was 3 of 113 (2.6%), as measured by appearance of new persistent Q waves on the serial postoperative electrocardiogram. Positive pyrophosphate scans were noted in 12 of 105 (12.4%) patients. It is concluded that, in the early stages at least, grafts to endarterectomized coronary arteries stay open and perfuse the myocardium as well as conventional saphenous vein grafts unless the myocardium is heavily scarred or unless residual disease remains.

Arteriosclerosis↗
PubMed1981

Cell-mediated immunity in American visceral leishmaniasis: reversible immunosuppression during acute infection.

Cell-mediated immunity was assessed in 14 Brazilian patients with acute untreated American visceral leishmaniasis (AVL) and in 11 healthy patients successfully treated 1 to 14 years previously. The diagnosis of AVL was established by demonstration of leishmania in bone marrow aspirates. The responsiveness of peripheral blood mononuclear cells to Leishmania chagasi antigens and phytohemagglutinin was studied in vitro. Soluble preparations of L. chagasi antigens were obtained from frozen-thawed promastigote cultures. L. chagasi antigen-stimulated lymphocytes from untreated AVL patients were unresponsiveness and incorporated a mean of 1.2 +/- 0.5 X 10(-3) cpm after a [3H]thymidine pulse. The cured AVL patients had 19.1 +/- 7.2 cpm, and 15 normal control subjects had 0.8 +/- 0.1 cpm. There were no differences in the response of controls and either untreated or cured AVL patients to phytohemagglutinin stimulation. Three of four untreated AVL patients responded to L. chagasi antigens when studied 2 to 4 weeks after therapy. The impaired response of lymphocytes from untreated AVL patients could not be attributed to either reduced numbers of circulating T cells or the inhibitory effect of monocytes or serum factors.

Adolescent↗
PubMed1981

Sudden death from coronary heart disease in young men: Pathologic findings.

Thirty-five of 40 young men whose deaths were caused by coronary heart disease died suddenly (less than 24 hours after onset of terminal symptoms). Many had myocardial necrosis or scars consistent with ischemic episodes that occurred hours, days, or months prior to death, yet 94% did not reach a hospital or receive medical care during the terminal episode. These results are from an investigation of 579 men, aged 25 to 44 years, who lived, died, and were autopsied in Orleans Parish, Louisiana. Among those who died of coronary heart disease, the vast majority had extensive advanced atherosclerotic lesions in the coronary arteries irrespective of suddenness of death. The frequent occurrence of gross scars indicative of healed myocardial infarction among young men, both black and white, who died suddenly of coronary heart disease may offer new hope that improved case finding might identify persons who could benefit from vigorous programs of early intervention.

Adult↗
PubMed1981

Community pathology of atherosclerosis and coronary heart disease in New Orleans. Morphologic findings in young black and white men.

Mortality from coronary heart disease is greater in young black men than in their white counterparts. On the other hand, the morphologic correlates of coronary heart disease, namely, coronary artery stenosis and occlusion, thrombus, and myocardial lesions are strikingly similar in coronary heart disease deaths regardless of race. Diseases related to atherosclerosis and coronary heart disease such as cerebrovascular disease, hypertension, diabetes, and chronic renal disease are also more frequent in young black men than in young white men, but the excess of coronary heart disease in blacks is evident irrespective of these diseases. Our findings are based on a community-wide survey of black and white men, 25 to 44 years of age, who lived, died, and were autopsied in Orleans Parish (county) Louisiana. Since the morphologic features of the disease are similar in the two races, investigation of risk factors is needed to further explain mechanisms associated with the relatively high coronary heart disease death rate in young blacks.

Adult↗
PubMed1980

Vibrio parahaemolyticus in Brazilian coastal waters.

Vibrio parahaemolyticus has been increasingly recognized as an important cause of acute diarrheal illness in Asia, Europe, Africa, Australia, and North America. We investigated whether this pathogen was also present in Brazil and found that 10% of the fish samples studied were contaminated with this halophilic vibrio. Positive cultures were obtained in three of 64 fish (5%) and in seven of 36 shell fish (19%).

Animals↗
PubMed1980

Synthesis and chiroptical characterization of prostacyclin diastereomers.

In the mercuri- and halo-cyclizations of PGF2 alpha methyl ester and its 11,15-bis(alpha- ethoxyethyl)-ether (or other protected forms) the exo-PGI1 derivative predominates independent of reagent and degree of protection of the PGF2 alpha sample used. Diastereomerically pure samples of exo- and endo-PGI1 and prostacycline (PGI2) were prepared. PGI0 epimers were prepared: catalytic hydrogenation of PGI2 Me ester provides exclusively the endo isomer. PGI2 methyl ester was found to be stable to extensive chromatography on silica, and to storage for at least a year in anhydrous ethanol at -20 degrees C. At pH 7.4 in 2:1 H2O:EtOH, the ester has a half-life in excess of 5 hr at 25 degrees C. A reproducible small scale (0.4-3 mg) synthesis of prostacyclin uses a modification of Whittaker's iodocyclization followed by DBN treatment. This procedure, developed with 15-3H-PGF2 alpha, proved widely applicable to PGF2 alpha analogs and diastereomers. The following prostacyclins (in the Me ester and Na salt forms) bearing the 5-en-6-yl ether unit were prepared in this way: ent-PGI2, rac-PGI2, 15-epi-PGI2, ent-15-epi-PGI2, 11-epi-PGI2, 8,9,12-epi-PGI2, E-PGI2, 13,14-dihydro-PGI2, and 13,14-dihydro-15-epi-PGI2. NMR comparisons for the methyl esters reveal that of the resonances (H-5,9,UU, 15) that appear at delta 4.0 +/- 0.6 ppm, the most deshielded is H-9 so long as the 5.6-olefin is Z. The 8R,9S-6,9-oxido-Z-5,6-ene unit is most readily characterized by its strong positive dichroic absorption at 210-230 nm. CD spectroscopy not only serves to confirm the presence of this unit in analogs, but also can be used for quantitative analysis of PGI2 solutions and for monitoring the rate of hydrolytic cleavage of these enol ethers.

Cyclization↗
PubMed1980

The Cornell-Bahia program, 1964-1975: an experience in international training.

A collaborative program of training and research between Cornell University Medical College and the Federal University of Bahia in Salvador, Brazil, was initiated in 1964 and continues to the present. The formation, organization, objectives, and research activities of and participation in the program for the period 1964 to 1975 are described. The major factors which contributed to the program's exceeding the expectations of the participating institutions are described.

Brazil↗