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Biomedical subjects

W J Taylor

Publications and source records attributed to W J Taylor.

At least 55 records · Page 3Linked to original sources
PubMed1985

Industrial exposure to organophosphorus compounds. Studies of a group of workers with a decrease in esterase-staining monocytes.

When an automated counting instrument using an esterase stain was employed, decreased monocyte counts were observed in a group of process workers exposed to organophosphate esters. Their monocyte counts were not found to be depressed with manual counting or with an automated counter using another staining method. The apparent depression was transient. In these workers and a comparison group, theoretical adverse consequences of decreased monocyte esterase and also possible changes in other esterases were explored. No anergy was seen with mumps or staphylococcal phage lysate hypersensitivity skin tests. Histology of the mumps reaction was similar in both groups. The depressed monocyte counts were significantly associated with a mild reduction in erythrocyte cell acetylcholinesterase, but no reduction was seen in plasma pseudocholinesterase or lymphocyte neurotoxic esterase.

Adult↗
PubMed1985

Neurotoxic and antihypertensive effects of phenytoin in turkeys.

Broad-Breasted White male turkeys were fed a control diet until 4 weeks of age, at which time they were randomized into a control group and two treatment groups which received 0.06% (38.7 mg/kg) and 0.09% (58.2 mg/kg) phenytoin, respectively, until termination of the experiment at 12 weeks of age. Plasma concentrations of phenytoin on the two dosages were 8.0 +/- 0.8 and 15.7 +/- 1.7 micrograms/ml. Systemic arterial blood pressure in the control turkeys was 214 +/- 5/171 +/- mm Hg and was reduced in a dose-related fashion to 185 +/- 8/143 +/- 11 and 156 +/- 5/125 +/- 4 mm Hg in the two treatment groups; likewise, the rate of systolic ejection (dp/dt maximum) was less in the phenytoin-treated turkeys. Heart rate also dropped significantly with drug administration but the difference between the two treatment groups was not significant. Evidence of neurotoxicity developed in 25% of the turkeys on the lower drug schedule; these birds had mean plasma phenytoin levels of 12.8 micrograms/ml as contrasted to the concentration of 8.0 micrograms/ml for the entire group. On 0.09% phenytoin 50% of the birds had abnormal signs and a mean phenytoin concentration of 20.5 micrograms/ml, whereas the mean drug level for the entire group on this drug level was 15.7 micrograms/ml. Early signs of neurotoxicity developed within 2 to 3 days of initiation of phenytoin and consisted of extensor rigidity of the neck and hyperactivity; at the higher drug concentrations, back pedaling and somersaulting appeared. General health and weight gain were not affected. No qualitative or quantitative changes were found in the Purkinje cells in the cerebellum of the affected turkeys.

Animals↗
PubMed1984

Improving drug prescribing in a primary care practice.

A model for improving physician prescribing that utilizes computerized feedback was studied in a family medicine residency practice. Resident and faculty physicians were stratified by level of experience and randomized into two groups. For 9 months the experimental group received monthly printouts identifying drugs they had prescribed by brand name with estimates of cost savings that might have been realized by prescribing generic drugs. The control group received no feedback. Prescription monitoring of both groups continued for 12 months after all feedback had ceased. Median weighted rates of generic prescribing for the experimental physicians were 14% for the baseline, 67% for the feedback, and 54% for the follow-up periods. Rates for the control physicians for the three periods were 32%, 37% and 31%, respectively. The increase in generic prescribing by physicians in the experimental group was significantly greater than for control physicians (P = 0.01). The feedback model improved rates of generic prescribing but should be evaluated for broader areas of physician prescribing.

Computers↗
PubMed1984

Treatment of subacute sclerosing panencephalitis: an overview.

Subacute sclerosing panencephalitis (SSPE) is a rare central nervous system degenerative disease that occurs primarily in children and adolescents. It is believed to be caused by a measles-like virus. Initial symptoms usually present as a variety of personality changes followed by myoclonus with progression of mental and motor deterioration, which leads to death within a few months to years. New experimental treatment with inosiplex has been shown to be helpful for patients stricken with this progressive neurological disease. A response to inosiplex therapy is best in patients with a slowly progressing form of the disease. Inosiplex treatment is safe with few adverse effects. The duration of treatment appears to be lifelong since many patients relapse when inosiplex therapy is discontinued. This article reviews the etiology, pathogenesis, and experimental treatment of SSPE.

Amantadine↗
PubMed1984

Cartilaginous metaplasia of the thoracic aorta of control turkeys and exacerbation by beta-aminopropionitrile.

Seventeen of sixty distal extremities of the thoracic aortas of 12-week-old control male turkeys and 37 of 40 distal extremities of the aortas of turkeys fed 0.07% beta-aminopropionitrile (BAPN) from 4 to 12 weeks of age contained areas of cartilaginous metaplasia when examined by light microscopy. The cartilaginous areas were generally elongated and located in the subendothelium of control turkeys, but a roundish area of cartilage was occasionally evident in the deep media. The magnitude of chondroplasia was enhanced by feeding BAPN; the extensive lesion usually extended from the subendothelium to deep in the media. Regardless of treatment, chondrocytes were pleomorphic, contained vacuoles, and had cytoplasmic processes. The cells were separated by pools of proteoglycans and connective tissue. The ultrastructure of chondrocytes in the aortas of both treatment groups was typical of this cell type. They had undulations or projections of the cell membranes. The cisternae of endoplasmic reticulum were dilated and contained electron-translucent material which was similar to extracellular proteoglycans. Golgi apparatus, free ribosomes, mitochondria, glycogen granules, filaments, and a centriole also were present in the cytoplasm. The extracellular matrix, which included collagenous and elastic fibers and also delicate fibrils and interconnecting matrix granules, separated adjacent chondrocytes by spaces of varying size.

Aminopropionitrile↗
PubMed1983

Sickled red cells in the Cervidae.

Hemoglobin polymerizes within the red cells from most species of deer when exposed to oxygen and an elevated pH. This hemoglobin aggregation is related to specific beta chains, which also dictate the precise alignment of the molecules and the type of cellular distortion. The typical sickle cell is virtually identical in shape, mechanical fragility, and viscosity to the human sickle cell, whereas the matchstick cell shares the latter properties but is an elongate cell from which spicules protrude in only one direction. The conditions of pH and pO2 that are required are beyond the usual physiological ranges; therefore, neither in vivo sickling nor disease is seen in deer. The genetic makeup of deer hemoglobin is of interest because of duplication of the alpha-chain gene loci and because of an extreme variability of the primary structure of the beta chains, at least in the white-tailed deer. Many facets of the deer hemoglobins remain fascinating objects for speculation. The evolutionary significance, if any, of the almost universal presence of sickling in the Cervidae is unknown. The meaning of the extreme polymorphism of the deer hemoglobins and the mechanisms by which they occurred are also obscure. It may be, however, that they may provide a tool by which one can elucidate the contact points and bonds that lead to the polymerization that produces the picturesque sickle cell.

Animals↗
PubMed1982

Carcinoma of the tonsillar region: results of external irradiation.

A retrospective analysis is made of 104 patients treated with photon megavoltage radiotherapy for squamous cell carcinoma of the tonsillar region during the period 1965--1975. Moderately differentiated squamous cell carcinoma was the most common histological grade. Fifty-three per cent of the cases presented with cervical lymphadenopathy with three cases of bilateral involvement. The three year local control rate was 100% for Stage I, 74% Stage II, 49% Stage III, and 33% Stage IV. Two Stage III cases and one Stage IV case developed subsequent contralateral neck disease. No patient with either T1N0 or T2N0 tumor failed in the ipsilateral or contralateral neck despite the fact that 42% of the T1N0 cases and 37% of the T2N0 cases were treated with unilateral portals. The prognostic significance of the T and N stages, treatment techniques, as well as dose response relationships are analyzed and the literature is reviewed.

Adult↗
PubMed1982

Effect of hydralazine on aortic rupture induced by B-aminopropionitrile in turkeys.

The effects of hydralazine on aortic rupture, hemodynamics and aortic ultrastructure were studied in turkeys fed B-aminopropionitrile (BAPN). A mortality rate of 24% due to hemopericardium and internal hemorrhage in turkeys fed only BAPN increased to 91% when turkeys were fed both BAPN and hydralazine, despite a significant reduction in blood pressure after both drugs. Death rates among turkeys fed BAPN and hydralazine were lowered by adding either dietary propranolol (53%), which lowered blood pressure and dP/dt max, or reserpine (67%), which reduced blood pressure and increased dP/dt max. Striking ultrastructural alterations of collagenous and elastic fibers of the aortic media, which were additive to the effects of BAPN alone, were induced by BAPN and hydralazine. This study demonstrates that a 6-week feeding of high levels of BAPN and hydralazine, which accumulates in vessel walls, can produce vascular injury and increase mortality from hemorrhage in lathyritic turkeys.

Aminopropionitrile↗
PubMed1982

Prostaglandins and the management of congenital heart disease.

Either continued patency or closure of the ductus arteriosus is needed to improve survival of infants with certain kinds of congenital heart disease. In many of these infants, the use of prostaglandin (PGE1) or a prostaglandin synthetase inhibitor (indomethacin) permits clinical stabilization in preparation for surgery or makes surgery unnecessary. Although these forms of therapy carry some risk, the risk does not outweigh that of the untreated congenital defects.

Age Factors↗
PubMed1982

Pharmacist-coordinated pneumonia and influenza vaccination program.

High-risk candidates in an ambulatory-care center were identified and immunized against pneumococcal pneumonia and influenza in a program coordinated by a pharmacist. Patients determined to be at increased risk for pneumococcal pneumonia were notified by letter of the vaccination program and encouraged to participate. Participants were then screened by their health-care providers to determine whether they were candidates for the vaccination. Those who received the pneumococcal pneumonia vaccine were later urged to be immunized against influenza virus. Of 1593 patients selected as possible vaccine candidates, 474 received the pneumococcal vaccine and 397 received the influenza vaccine. No confirmed cases of pneumococcal pneumonia and only one case of flu-like syndrome developed among the immunized patients. Income from the program exceeded its cost, excluding the salaries of the center's employees. Substantial savings were projected from reduced future treatment costs. The pharmacist had initiated and coordinated a successful effort to increase vaccine use and decrease morbidity.

Community Health Centers↗
PubMed1980

The interaction of amine local anaesthetics with muscarinic receptors.

1 Amine local anaesthetics inhibited the binding of (-)-[3H]-quinuclidinyl benzilate ((-)-[3H]-QNB) to muscarinic receptors in crude synaptosomal preparations from guinea-pig brain. The order of potency was SKF 525A greater than tetracaine greater than procaine congruent to quinidine greater than procainamide greater than bupivacaine greater than lignocaine greater than prilocaine. 2 The concentration of tetracaine or prilocaine causing 50% inhibition of the receptor-specific binding of [3H]-QNB varied linearly with the concentration of [3H]-QNB present for the range of concentrations of prilocaine used and at lower concentrations of tetracaine, thus providing evidence for a competitive interaction. The affinity constant for tetracaine was 2.6 +/- 0.2 x 10(5) M-1 and that for prilocaine 2.6 +/- 0.8 x 10(3) M-1. At higher concentrations of tetracaine the interaction appears to diverge from simple competitive kinetics. 3 The log dose-response curve for the contractile response of longitudinal muscle strips from guinea-pig intestine to carbachol was shifted in a parallel fashion by low concentrations of tetracaine, but flattened by higher doses. A similar effect was observed for both lignocaine and prilocaine. The affinity constants for tetracaine and prilocaine calculated from the parallel shifts, 1 x 10(5) M-1 and 4 x 10(3) M-1, respectively, were in reasonable accord with the binding data. 4 The curve for the inhibition of [3H]-QNB binding by carbachol was not significantly altered, either in position or shape, in the presence of 1 mM prilocaine. Thus there is no evidence that prilocaine, which increases the affinity of nicotinic acetylcholine receptors for agonists, has any similar effect on agonist binding to muscarinic receptors.

Amines↗
PubMed1980

Crystalline inclusions in erythrocytes parasitized with Babesia equi following treatment of ponies with imidocarb.

Four splenectomized Welsh ponies were infected with Babesia equi. Two ponies were treated with imidocarb dipropionate, and two were not treated. By light microscopic examination, 1% to 2% of the parasitized erythrocytes of treated ponies contained crystalline inclusions. The crystals were rectangular, diamond, or burr shaped. They occupied most of the erythrocytic cytoplasm, and, as a result, the remainder of the pale staining cytoplasm was inconspicuous in Wright-Giemsa-stained blood smears. The size and shape of intraerythrocytic inclusions varied when examined by electron microscopy, but in most instances they were either adhered to or were located close to the parasite. The sides of crystals were either smooth or serrated, and corners were either sharp or notched. Fractures or faults were common in large crystals. Parasitized erythrocytes of nontreated ponies and nonparasitized erythrocytes of treated ponies did not contain crystals. Four hemoglobulin types were identified in five noninfected, nontreated Welsh ponies from the same herd.

Animals↗
PubMed1979

Radiation therapy for localized prostate cancer.

Since 1965, 401 patients with prostate cancer have received intensive local pelvic radiation therapy at the Virginia Mason Medical Center. Two hundred seventy-seven of these patients were treated from 1965 through 1975, comprising the study group. Two hundred twenty-one of this series were in the Stage C category. The 36 Stage B cancers were either medically nonoperable, or advanced extent, or had high-grade histopathology. Ten patients each were in diffuse Stage A or Stage D groups, the latter receiving local palliative intensive treatment to the prostate area. The mean age of the patients was 67.6 years. The five year survival of the Stage C group was 57.7%. There was no apparent influence on the survival of irradiated Stage C patients who received estrogen therapy. Current treatment techniques employ 10 megavolt photon beam with whole pelvic nodal fields and bilateral arc rotational boost fields. The incidence of reactions and complications is presented.

Aged↗
PubMed1979

Prenatal ethanol exposure in mice: teratogenic effects.

C57BL/6J mice were fed a liquid diet in which 17, 25, or 30% of the calories were derived from ethanol from the fifth through the tenth day of gestation. Control mice were fed lab chow or pair-fed identical diets, except that sucrose substituted isocalorically for ethanol. At term the fetuses were removed and, following fixation, examined by microdissection. The incidence of fetal resorptions and congenital malformations increased in a dose-related manner. Anomalies included skeletal, neurological, urogenital, and cardiovascular systems. These data indicate that in mice, an alcohol diet which is adequate in vitamins and protein results in increased fetal wastage and birth defects.

Abnormalities, Drug-Induced↗