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Biomedical subjects

G Myers

Publications and source records attributed to G Myers.

71 records · Page 4Linked to original sources
PubMed1979

Early malfunction of transvenous pacemaker electrodes. A three-center study.

A 3-year study by three medical centers has revealed a 1-year electrode malfunction rate of 7.4%; most malfunctions occurred within the first 30 days. The incidence of unavoidable early malfunction (3.2%) fell within the 5% standards suggested by the committee report of the Inter-Society Committee on Heart Diseases. Incidences of obscure cause (3.2%) may be difficult to identify prospectively and may be, to a certain extent, unavoidable. The majority of the malfunctions (4.2%) showed specific clues that indicated that they were preventable. Successful repositioning was achieved on the first attempt in 80.6% of the cases with malfunction, and only 0.7% required ultimate myocardial electrode implantation. The principal clues to potentially unsatisfactory positioning included the presence of a large right ventricle with or without tricuspid insufficiency, current thresholds greater than 0.5 mA and ST-segment deviations on the intracardiac electrogram of less than 2 mV. Electrode malfunction may be more common with bipolar than with unipolar electrodes; but significant differences in the incidence of malfunction among different unipolar electrodes were observed. These data indicate that further developments in transvenous electrode design are warranted.

Arrhythmia, Sinus↗
PubMed1979

The disposition of 3-methyl-2,3-dihydro-9H-isoxazolo[3,2-b]-quinazolin-9-one (W-2451).

3-Methyl-2,3-dihydro-9H-isoxazolo[3,2-b]quinazolin-9-one was readily absorbed, metabolized and eliminated in rat, dog, monkey and man. The radioactivity elimination after i.v. or p.o. administration of W-2451-14C in rats was biphasic with corresponding half-lives of 1.8 and 8.7 hours. Plasma half-lives of W-2451 in the dog, rhesus monkey and man were 1.4, 1.2 and 3.2 hours, respectively. In the rat, excretion via the urine was predominant, no significant accumulation in tissue occurred. The only major metabolite found in rat and dog urine, rat plasma and in the rat liver 9000 g supernatant fraction was the 3-hydroxy derivative of the drug. The unsaturated compound with the double bond in the 2,3-position and other hydroxylated metabolites were also present. Very little free or conjugated anthranilic acid and 3-(o-carboxy-phenylimino)-4-methylisoxazolidine were found.

Analgesics↗
PubMed1979

Metabolism and pharmacokinetics of 4-(p-chlorophenylthio)butanol (W-2719) in the rat and dog.

4-(p-Chlorophenylthio)butanol (W-2719) administered orally to rats and dogs is rapidly absorbed, metabolized and excreted. The only major biotransformation product found in blood was p-chlorophenylthioacetic acid (W-2683). No W-2719 or the intermediary p-chlorophenylthiobutyric acid (W-2718) could be found in plasma after oral administration of the drug. When W-2719 was given i.v. to dogs, both W-2719 and W-2718 appeared in plasma but each had a very short half-life of about 10 min. After an oral dose of W-2719 to dogs the plasma content of W-2683 peaked at 4-6 h, amounting to approximately 20% of the dose. More than 91% of the dose was excreted with 48 h, 83% in urine and 9% in feces. The predominant excretion product in urine was p-chlorothiophenol, most of which was excreted in a conjugated form. The other major urinary metabolite was W-2683, while smaller amounts of W-2718 and unchanged drug were also found. No significant effect of prolonged dosing of 14C-W-2719 to dogs was observed on plasma 14C levels, peak time, 14C half-life or excretion and composition patterns.

Animals↗
PubMed1976

Part I: abnormal patterns and physiological variations in magnetocardiograms.

Magnetocardiograms (MCGs) of six subjects with representative cardiac abnormalities and of one well-studied normal subject are compared with the 12-lead ECGs and VCGs of these subjects. The MCGs are recordings of the component of the magnetic vector which is normal to the skin, measured across the chest on a 5 cm X 5 am grid; an example is also presented of a sequence of instantaneous MCG maps. The heart abnormalities include myocardial infarction, angina pectoris, intraventricular conduction disturbances, and ventricular hypertrophy. The various MCG maps of the normal subject show MCG changes as a result of changes in body morphology (loss of weight), changes in the subject's position during recording, and changes as a result of exercise. They are presented as a basis for understanding some of the variability of MCG maps.

Angina Pectoris↗
PubMedDate not supplied

Neurodevelopmental and health outcomes in term infants treated with surfactant for severe respiratory failure.

OBJECTIVE: Analysis of health, neurodevelopmental, and school performance outcomes in a pilot study of term and near-term infants with respiratory failure due to pneumonia or meconium aspiration treated with surfactant. STUDY DESIGN: Retrospective review of medical records, neurodevelopmental and psychosocial evaluations, and parent and teacher surveys. RESULTS: Of the 14 patients enrolled, only one was rehospitalized, for pneumonia. Three were reported to have episodes of wheezing, two of whom required bronchodilators. One patient had unilateral hearing loss, one had a full-scale intelligence quotient that was below normal, and all but one patient for whom complete results were obtained were performing at or above grade level. CONCLUSION: Term and near-term newborns with moderately severe respiratory failure treated with surfactant can, in general, be expected to recover completely and have normal general health, neurodevelopmental outcome, and school performance.

Achievement↗
PubMedDate not supplied

Characteristics of adolescents with poorly controlled diabetes referred to a tertiary care center.

The medical and psychosocial findings concerning 15 adolescents with poorly controlled diabetes referred to a tertiary center are reviewed. While referring physicians usually attributed poor metabolic control to an unusual idiosyncratic pathophysiologic aspect of diabetes, all patients were managed by conventional treatment regimens. Psychosocial problems, including excessive school absence, depression, and social isolation were frequent in this population, and in eight families emotional factors appeared to contribute to the development and persistence of poor metabolic control. Eight patients accepted psychosocial intervention consisting of individual, family, and/or group counseling. Not one of the patients has been hospitalized for ketoacidosis in the subsequent 12-18-mo period, and their psychosocial functioning as adolescents is improved. Hemoglobin A1c levels remained elevated. Psychosocial factors in adolescents experiencing poor metabolic control should be addressed.

Absenteeism↗