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Biomedical subjects

S Feldman

Publications and source records attributed to S Feldman.

At least 361 records · Page 20Linked to original sources
PubMed1978

Pharmacokinetics of acetohydroxamic acid. Preliminary investigations.

The pharmacokinetics of acetohydroxamic acid (AHA), an agent being evaluated in the treatment of infection-induced urinary stones, have been examined in rats and man. After oral and intravenous administration of AHA to rats the biologic half-life and total body clearance seemed to be dose dependent. Comparison of the oral and intravenous data indicated that less than 100 per cent of an oral dose of AHA reaches the systemic circulation intact and that this percentage is dose related. Studies performed in human subjects indicated that AHA is rapidly absorbed from the gastrointestinal tract and has a biologic half-life of 5 to 10 hr in subjects with normal renal function. The half-life and percent of dose recovered in the urine seem to be dose related and dependent upon renal function.

Administration, Oral↗
PubMed1978

Effect of heptabarbital on bioavailability of bishydroxycoumarin in the rat.

The influence of oral administration of heptabarbital on the gastrointestinal absorption of bishydroxycoumarin (BHC) was investigated in rats. Pretreatment of the animals with 20 mg/kg heptabarbital twice dialy for three days prior to the administration of 50 mg/kg BHC resulted in a 40% decrease from controls in the area under the BHC plasma concentration time curve (AUC). Preliminary studies indicated that a similar decrease in gastrointestinal absorption of BHC could be seen following a single oral dose of heptabarbital administered concomitantly with the anticoagulant.

Administration, Oral↗
PubMed1977

Successful chemoprophylaxis for Pneumocystis carinii pneumonitis.

In a randomized, double-blind, placebocontrolled study to evaluate the efficacy of trimethoprim-sulfamethoxazole for the prevention of Pneumocystis carinii pneumonia, we studied 160 patients with cancer who were at high risk for this pneumonia over a two-year period. Seventeen of the 80 patients receiving a placebo acquired P. carinii pneumonitis, whereas none of the 80 given 150 mg of trimethoprim and 750 mg of sulfamethoxazole per square meter per day had the infection P less than 0.01). Bacterial sepsis, pneumonia other than that caused by P. carinii, acute otitis media, upper-respiratory-tract infections, sinusitis and cellulitis occurred less frequently in recipients of the drug than in the placebo group (P less than 0.01 in each case). Oral candidiasis was the only adverse effect ecountered from trimethoprim-sulfamethoxazole administration. The study shows the combination to be highly effective in the prevention of P. carinii pneumonitis.

Adolescent↗
PubMed1977

Percutaneous transthoracic needle aspiration of the lung. Diagnosing Pneumocystis carinii pneumonitis.

Percutaneous transthoracic needle aspiration was performed on 228 occasions to obtain lung specimens from 202 patients with suspected Pneumocystis carinii pneumonitis. In 121 patients the diagnosis was established by identifying P carinii organisms in lung aspirates. Six patients whose aspirates did not contain P carinii were found to have the organism at autopsy. Findings from toluidine blue O and Gomori methenamine silver nitrate stains were equally satisfactory for detecting P carinii, but the percentage of specific diagnosis was higher when specimens were stained with both. Pneumothorax that required a thoracotomy tube occurred in 39 patients. Other infectious agents, either bacteria or fungi, were found in only four patients. Percutaneous pulmonary needle aspiration--when performed under fluoroscopic guidance--is a rapid and effective method for the diagnosis of P carinii pneumonitis.

Adolescent↗
PubMed1977

Influenza in children and young adults with cancer: 20 cases.

The purpose of this study was to characterize the clinical features of laboratory-confirmed influenza in 20 children and young adults with cancer who were receiving immunosuppressive therapy. Viruses isolated from pharyngeal and nasopharyngeal cultures were identified as the A/Hong Kong/1/68 strain or one of its variants, either A/England/42/72, A/Port Chalmers/1/73, or A/Victoria/3/75. Although the signs and symptoms of influenza in our patients were not unusual, the clinical course lasted twice as long as in the general population. Complications developed in only 3 patients and were related to secondary bacterial infections rather than influenza. An important sequelae of influenza was the interruption of cancer therapy in 16 patients for periods of 4 days to 3 1/2 weeks. The severity of influenza did not appear related to type or activity of malignancy or to duration or specific form of cancer therapy. Guidelines for the prevention and management of influenza in children with cancer are recommended.

Adolescent↗
PubMed1977

A viremic phase for herpes zoster in children with cancer.

Eight childhood cancer patients with herpes zoster were serially tested for the presence of varicella-zoster virus in blood. Cell cultures of leukocyte-rich plasma from four patients were positive for the virus. In this study viremia was clearly related to dissemination of dermal lesions-the spread of zoster lesions outside an infected dermatome. The child with the longest viremic phase, five days, had the longest and most severe course of skin dissemination, as well as biochemical evidence of hepatitis. One patient with viremia had advanced embryonal carcinoma and died of disseminated tumor before her clinical course could be evaluated. These observations, the first to document a viremic phase for herpes zoster in immunosuppressed children, furnish an added criterion for evaluation of antiviral drugs and live-virus vaccines in the treatment and prevention of varicella-zoster infections.

Acute Disease↗
PubMed1977

Signal-processing techniques in a computerized hearing aid test system.

General background is given to describe the factors leading up to the implementation of a computerized hearing aid test system in a production environment. The digital measurement methods for determination of the required acoustal components such as fundamental, rms, distortion, etc., in the presence of noise are discussed. The use of the concept of the average cycle for repetitive signals is described with its advantages in a Fourier type system. An algorithm for measuring rms for nonrepetitive signals that trades off resolution for memory size is described. Features and advantages of computerized testing of hearing aids are listed.

Acoustics↗
PubMed1977

Iontophoretically applied corticosteroids do not affect the firing of hippocampal neurons.

In view of the possible role of the hippocampus in the neuroendocrine regulation of ACTH secretion, experiments were conducted in rats and cats in which cortisol (C) and corticosterone (CS) were applied by iontophoresis and pressure microinjection while recording from single identified pyramidal cells in the dorsal hippocampus, using multi-barrelled microelectrodes. None of the more than 500 cells tested responded with a significant change in firing rate. The possible relation of these findings to neuroendocrine regulation of ACTH secretion is discussed.

Action Potentials↗
PubMed1977

Adrenocortical responses to olfactory stimulation in rats with partial hypothalamic deafferentations and lesions.

Previous experiments from this laboratory using complete hypothalamic deafferentation have demonstrated that the adrenocortical discharge following olfactory stimulation is essentially mediated by neural pathways. In order to identify the neural afferents and the hypothalamic areas involved, this response was studied in rats with anterior (AD) and posterior (PD) partial hypothalamic deafferentations as well as in animals with bilateral lesions in the ventrolateral medial forebrain bundle (VMFB) and the gemini region (GR) in the hypothalamus. While rats with PD had a normal adrenocortical response to odor stimulation, this was completely inhibited in animals with AD and partially reduced in VMFB and GR lesioned rats. These data would indicate that the adrenocortical response following olfactory stimulation is mediated by anterior afferents to the hypothalamus and involves the VMFB and GR.

Animals↗
PubMed1977

Effect of anti-parkinsonism drugs on gastric emptying and intestinal transit in the rat.

The effect of atropine sulfate, trihexyphenidyl HCl, benztropine mesylate, diphenhydramine HCl and ethopropazine HCl on gastric emptying and intestinal transit of a phenol red solution in the rat was examined. Intraperitoneal administration of 0.3 mg/kg atropine, 1.2 mg/kg benztropine and trihexyphenidyl results in a marked decrease in gastric emptying and intestinal transit rate when compared to controls. Oral administration of these agents produced variable and unpredictable results. Single and multiple oral dose (0.6--3 mg/kg) studies with trihexyphenidyl failed to produce any significant decreases in gastric emptying rates. A single oral dose of benztropine (0.6--3 mg/kg) failed to reduce the gastric emptying rate, but multiple dose studies produced a significant decrease in the gastric emptying rate. Effects on gastric emptying and intestinal transit were seen after single and multiple oral doses of diphenhydramine and ethopropazine.

Administration, Oral↗
PubMed1977

[Hypoplasia of the right ventricular myocardium (Uhl's disease). Report of a case with review of the literature (author's transl)].

A rare case of congenital hypoplasia of the right ventricular myocardium ("Parchment Right Ventricle" or Uhl's disease) diagnosed by angiocardiography is presented. The predominant clinical feature was recurrent paroxysms of severe arrhythmias which could be controlled only by electric shock. Right heart failure was also present. After a follow-up period of 8 years, the patient, now 27 years old, on diuretic and antiarrhythmic treatment, is well. The literature on Uhl's disease is reviewed and classified into two clinical types; a fatal infantile type in which extreme hypoplasia is present, and a milder adult type in which the anatomical lesion is usually more limited. In the infantile type intractable heart failure was invariably present; in the adult type severe arrhythmias often constituted the major clinical problem. Some of the difficulties in diagnosis and treatment are emphasized.

Adolescent↗
PubMed1977

Apparent metabolism of allopurinol by blood--a preliminary report.

Allopurinol is converted to a presently unidentified metabolite by whole blood, both in samples prepared in vitro as well as samples from subjects administered the drug. The apparent plasma concentration of allopurinol, as determined by HPLC, is dependent upon the length of time between sample preparation or sample withdrawl and the centrifugation and removal of plasma. Oxypurinol does not undergo the same conversion, nor does it affect the loss of allopurinol.

Allopurinol↗