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Biomedical subjects

W R Smith

Publications and source records attributed to W R Smith.

At least 73 records · Page 4Linked to original sources

Nephrotoxicity of paraquat in man.

Renal function studies were performed in three cases of paraquat poisoning. Acute renal failure was observed in all three cases. Glomerular filtration rate improved for two patients who survived three weeks, illustrating the reversible nature of paraquat-induced acute renal failure. A mild to moderate transient proteinuria was observed during the first and second weeks following paraquat ingestion. Renal glucosuria, marked amino aciduria, and increased fractional excretion of phosphorus, sodium, and uric acid were observed. These findings, which have not been previously described in man, are indicative of proximal tubular dysfunction and parallel observations previously made in experimental animals.

Acute Kidney Injury↗

Redistribution of blood flow in acute hypometabolic behavior.

Cardiac output, renal and hepatic blood flows, arterial lactate concentration, and minute volume were measured before, during, and after 40 min of rest induced either by the practice known as "transcendental meditation" (TM) or by an ordinary eyes-closed rest-relaxation period. Two groups of normal young adults were studied: one group consisted of regular practitioners of TM and the other of similar individuals studied prior to learning this technique. Marked declines of renal blood flow were noted in both groups. Decline of hepatic blood flow, increased cardiac output, decreased arterial lactate, and minute volume were also recorded in the TM-induced rest period. These changes imply a considerable increase of nonrenal, nonhepatic blood flow during TM (44%) and, to a lesser extent, during rest (12%). Increased cerebral and/or skin blood flow is hypothesized to account for part of the redistributed blood flow in the practitioner.

Cardiac Output↗

Deposits of immunoglobulin and complement in the pulmonary tissue of patients with "heroin lung".

Pulmonary tissues from six patients who died with a clinical diagnosis of "heroin lung" (heroin-induced pulmonary edema) were examined with the light microscope and electron microscope. Immunofluorescent microscopic analysis revealed multifocal granular alveolar septal deposits of IgM in all patients, C3 complement in five patients, IgG in four patients, fibrinogen in three patients, and IgA in two patients. IgM, IgG, IgA, and C3 complement were eluted from the lungs of these addicts with citrate buffer with a low pH. No deposition of albumin was found in any of the specimens. These findings are believed to represent the first report of immune complexes in the alveolar capillary membrane in patients with heroin-induced pulmonary edema. Electron-microscopic studies revealed a proteinaceous plasma-like fluid in the alveolar spaces, thereby confirming the heroin induced pulmonary edema. Mechanisms of transport of edematous fluids from alveolar capillaries to alveolar spaces in lungs from heroin addicts are considered.

Adult↗

Pulmonary ultrastructure of the late aspects of human paraquat poisoning.

The pulmonary ultrastructure of the late aspects of a case of human paraquat poisoning is investigated and compared with normal human pulmonary ultrastructure. Alveoli in the paraquat patient are numerically reduced in comparison to the control. They are filled with edematous proteinaceous plasma-like fluid containing erythrocytes, macrophages, leukocytes, fibroblast-like cells, platelets, and fibrin. These alveoli are lined by granular pneumocytes. Interstitial areas in the paraquat patient are greatly expanded and there are no alveolar septums. Interstitial areas contain proteinaceous plasma-like material, collagen, fibrin, platelets, mature fibroblasts, plasma cells, many leukocytes, numerous erythrocytes, and capillaries. Capillary permeability seems to be enhanced in the paraquat patient either by vesicles forming transendothelial channels or pores or by disruption of endothelial cells.

Adolescent↗

Pulmonary tissue concentrations of ethchlorvynol after intravenous injection.

Noncardiogenic pulmonary edema has been reported to follow the intravenous use of ethchlorvynol (Placidyl) in both human clinical and animal experimental situations. In a further attempt to define ethchlorvynol-pulmonary tissue inter-relations, we measured ethchlorvynol concentrations in venous and arterial blood and lung and liver tissue of dogs after intravenous injection of 15 to 25 mg of the drug per kg of body weight. In 10 dogs, the mean +/- SEM lung concentrations 1, 3, and 5 min after injection were 70 +/- 20, 50 +/- 13, and 24 +/- 9 mug per g of tissue, respectively. Simultaneous mean +/- SEM venous contrations were 75 +/- 40, 29+/-5, and 22 +/- 5 mug per ml of blood, respectively. During minutes 1 and 3, the liver concentrations were lower than those found in the lung. In an additional 3 dogs, injection of ethchlorvynol into the portal vein led to higher concentrations (at all sample times) in the liver when compared to the lung. In vitro lung slice studies using ethchlorvynol labeled with iodine-131 revealed no active energy-dependent uptake. Intravenously administered ethchlorvynol rapidly fluxes into and out of lung tissue, apparently following the laws of diffusion.

Animals↗

Emotional history and pathogenesis of cancer.

Emotional history was evaluated in a sample of cancer patients and a sample of noncancer patients who were hospitalized for treatment. An in-depth interview was conducted with each S to identify the frequency, duration, and intensity of each emotion-provoking event that he could remember across his life history. Evaluations of the interview information identified more frequent and intense emotional events in the Ss with cancer than in the controls who did not have cancer.

Adult↗

Rural alcohol abuse.

One hundred and forty-eight rural males between the ages of 18 and 60 volunteered to be tested and were interviewed with a series of scales and background information items that were selected to predict alcohol abuse or nonabuse. The subjects were classified as Black abusers, Black nonabusers, White abusers, and White nonabusers. Major sections of the test and interview format included measures of achievement need, alienation, tolerance of deviance, leisure time, religious fundamentalism, general deviation, mobility, age, family size, and education. Criteria of abuse and nonabuse were based on interview information related to quantity consumed, circumstances for drinking, problems related to drinking, and a community estimate from references. Field research data across 32 Texas villages were used to develop recommendations for education, information, and treatment for strictly rural American areas. Analysis of variance methods identified significant differences between abusers and nonabusers on measures of tolerance of deviance, religious fundamentalism, general deviation, mobility, age, and education.

Adolescent↗

Coagulation factors and fibrinogen in pleural effusions.

31 pleural effusions from 27 patients with varied diseases were studied for specific coagulation factors and fibrinogen. In all fluids, exudates had a higher content of factors and fibrinogen than transudates. When pleural fluid to plasma total protein ratios were compared to specific coagulation factors a positive correlation existed for all. This was not true for fibrinogen. There was a poor correlation between the molecular weights of the specific factors and fibrinogen and their appearance in the pleural fluid. The concentration of factor XII in 35% and factor XI in 11% of pleural fluid exceeded their respective plasma concentration.

Adult↗

Tonsillar hypertrophy in an adult with obesity-hypoventilation syndrome. The use of the flow-volume loop.

A 29-year-old obese man had marked tonsillar hypertrophy, somnolence, hypoxemia, and hypercapnia. Endotracheal intubation followed by tracheostomy relieved the hypoventilation. Weight loss improved the arterial blood gas levels. Sequential upright and supine flow-volume loops were compatible with a fixed upper-airway obstruction (such as would occur) with enlarged tonsils) prior to tonsillectomy. Following surgery, the expiratory flow-volume curve was abnormal in the supine position, consistent with the additional diagnosis of posterior pharyngeal hypotonia. Thus, in this patient the unique combination of tonsillar hypertrophy, posterior pharyngeal hypotonia, obesity, and a depressed respiratory center led to retention of carbon dioxide.

Adult↗

Ethchlorvynol (Placidyl)-induced pulmonary edema.

Two patients experienced severe nonhemodynamic pulmonary edema following the intravenous injection of 25 and 40 mg/kg of body weight of ethchlorvynol (Placidyl). The pulmonary edema cleared rapidly. Injection of Placidyl (12 to 80 mg/kg of body weight) intravenously into dogs caused acute, severe, nonhemodynamic pulmonary edema (as evidenced by markedly elevated lung weights and microscopic evidence of intra-alveolar edema), hypotension with a relative bradycardia, and a decreased cardiac output. Injection of polyethylene glycol, the vehicle in which ethchlorvynol is diluted, did not reproduce the syndrome.

Adult↗

Paraquat poisoning: new aspects of therapy.

Clinical, laboratory, and pulmonary physiologic features of three fatal cases of paraquat poisoning are presented. Experimental investigations and clinical experience would suggest several possible means of modifying paraquat toxicity. The following specific therapeutic interventions, several of which had previously been applied only in experimental circumstances, were used: (1) inhibition of absorption of paraquat with Fuller's Earth and catharsis by magnesium sulfate, (2) elimination of absorbed paraquat by hemodialysis with ultrafiltration and forced diuresis, (3) competition by d-propranolol for tissue binding sites, (4) modification of direct pulmonary tissue effects of paraquat by hypoxic breathing mixtures, superoxide dismutase, and corticosteroids. Treatment was unsuccessful. However, our clinical experience and data concerning paraquat concentration in body and dialysis fluids suggest a therapeutic approach aimed at preventing early and progressive tissue damage. A combination of Fuller's Earth and magnesium sulphate should be used immediately and in frequently repeated doses to prevent absorption. Diuresis and haemodialysis should be instituted as soon as possible to increase excretion. Hypoxic atomspheres should be created urgently to produce a PaO2 of 40-45 mmHg, and the use of superoxide dismutase be further investigated. It is hoped that the high mortality of paraquat poisoning will be modified by this combined approach of early and intensive treatment.

Adolescent↗