Search PubMed⌕ Search

Biomedical subjects

E Foster

Publications and source records attributed to E Foster.

107 records · Page 6Linked to original sources
PubMed1980

Mercapto steroids in protection against mercury and lead poisoning.

When thiocholesterol is administered as liposomes, it provides significant protection against methylmercuric chloride in mice when given in three intraperitoneal injections, 0.5 hr before and 2 and 8 hr after the methylmercuric chloride. Thiositosterol, 5 alpha-cholestane-2 beta, 3 alpha-dithiol, and 5 beta-cholane-3 beta, 24-dithiol also are active, but 3 alpha-mercapto-5 alpha-pregnan-20-one, 6 beta-mercapto-5 alpha-cholestane-3 beta, 5 alpha-diol, 3 beta-mercapto-5 beta-cholanic acid, and adamantanethiol are ineffective under these conditions. Adamantanethiol is somewhat effective when administered in soybean oil. Cholestanyl amine was treated with acetylthiosuccinic anhydride to give the half amide; cleavage with hydroxylamine liberated the thiol group. This product is active against both methylmercuric chloride and lead nitrate.

Animals↗
PubMed1979

Quantitative age related histologic changes in the human vas deferens.

Sections of vas deferens from 50 men between 27 and 82 years of age were examined histologically for evidence of changes in muscle area and for changes in per cent of the cross-sectional area of the vas deferens that was occupied by muscle and connective tissue as a function of age. No variation in quantitative measurement of muscle or connective tissue could be correlated with age but a diffuse increase in unmeasurable amounts of connective tissue was seen with increasing age.

Adult↗
PubMed1978

Synthesis and evaluation of sulfur-containing steroids against methylmercuric chloride toxicity.

Sulfur-containing steroids, analogs, and derivatives were synthesized for evaluation in mice suffering acute toxicity from methylmercuric chloride. Steroids were administered by intraperitoneal injection, by stomach tube feeding, or by absorption through the tail skin. Thiocholesterol and the thiocholanoic acids were effective if given prior to poisoning. The thiosteroids were significantly more effective than penicillamine or dimercaprol under these conditions.

Administration, Oral↗
PubMedDate not supplied

Synthesis of some analogs of estradiol.

As part of a search for estradiol derivatives designed for conjugation to carboxyl or amine functions of anti-cancer agents or suitable derivatives thereof, estradiol analogs with side chains at the C-16 or -17 position were prepared for biological assay. These analogs include several which have a substituted nitrogenous function at C-17. The avidity of some of these analogs for binding to estrogen receptor was found to be of a low order.

Estradiol↗
PubMedDate not supplied

Conjugates of steroids and anti-cancer agents. III. The synthesis of estrynamine and certain derivatives.

Propargyl amine was protected by condensing it with 2,5-hexane-dione to give 2,5-dimethyl-N-(2'-propyn-1'-yl)pyrrole (2). The latter was converted to the corresponding Grignard reagent with ethylmagnesium bromide, and then condensed with estrone tetrahydropyranyl ether to give 17 alpha-[3'-(2'',5''-dimethyl-1''-pyrryl)-1'-propyn-1'-yl)-1,3 ,5( 10)- estratriene-3,17 beta-diol 3-tetrahydropyranyl ether (3), in 85% yield. Acetic acid and methanol cleaved the tetrahydropyranyl ether group, and hydroxylamine and sodium bicarbonate cleaved the pyrrole ring to give 17 alpha-(3'-amino-1'-propyn-1'-yl)-1,3,5(10)-estratriene-3,17 beta-diol (1), estrynamine. Several derivatives and analogs of 1 were also synthesized. Estrynamine binds to estrogen receptor with an RBA of 0.0045 (estradiol = 1.0). Several of the compounds, including estrynamine, are weak estrogens (stimulation of prolactin synthesis).

Animals↗
PubMedDate not supplied

Measurement of aortic blood flow by Doppler echocardiography: temporal, technician, and reader variability in normal subjects and the application of generalizability theory in clinical research.

Although Doppler echocardiographic measurements of aortic flow have been found to correlate with stroke volume, the reliability of this technique is unknown. The purpose of this study was to measure the reliability of Doppler estimates of cardiac output by identifying and estimating the magnitude of different sources of error. We measured the reliability of Doppler estimates of cardiac output by identifying the magnitude of sources of error in 11 subjects with studies performed by two technicians and read by two readers. Analysis with generalizability theory demonstrated that the largest portion of the total variance was from differences among patients, with a smaller contribution due to day-to-day variability. Variability due to technician was low for continuous wave Doppler (2.0%), but high for pulsed wave (23.2%). Thus continuous wave, but not pulsed wave Doppler measurements, can be used to detect serial changes in cardiac output due to an intervention.

Adult↗
PubMedDate not supplied

Pulsed Doppler characterization of left atrial appendage flow.

Recent evidence suggests that left atrial (LA) appendage velocities may provide clues to the thrombogenic potential of this structure. Pulsed Doppler evaluation of LA appendage flow during transesophageal echocardiography was performed in 109 patients to evaluate the effects of rhythm, mitral regurgitation, and spontaneous contrast. During sinus rhythm, there was a forward LA appendage contraction wave of 46 +/- 18 cm/sec followed by a retrograde filling wave of 46 +/- 17 cm/sec. In 40% of the patients in sinus rhythm, additional forward and retrograde velocities of 23 +/- 10 and 22 +/- 11 cm/sec, respectively, were seen. In contrast, atrial fibrillation was associated with reduced forward and retrograde flows in an irregularly irregular pattern. In sinus rhythm moderate to severe mitral regurgitation did not appear to affect the LA appendage velocities. Last, although forward LA appendage velocities were found to be significantly reduced in patients with spontaneous contrast by univariate analysis, multivariate analysis demonstrated that only the presence of atrial fibrillation was a significant predictor for spontaneous contrast.

Atrial Fibrillation↗
PubMedDate not supplied

Streptococcal endocarditis temporally related to transesophageal echocardiography.

A case of streptococcal sanguis endocarditis temporally related to a transesophageal echocardiogram is reported; and the literature on the incidence of bacteremia occurring during transesophageal echocardiography is reviewed. On the basis of this case and review of the literature, a reevaluation of the current guidelines for endocarditis prophylaxis during this procedure is recommended.

Echocardiography↗
PubMedDate not supplied

The role of transesophageal echocardiography in critical care: UCSF experience.

The applications of transesophageal echocardiography (TEE) now encompass the arena of critical care. We reviewed the indications, findings, and outcome of TEE in the critical care setting in a tertiary care hospital and report our experience. Eighty-three transesophageal echocardiograms were performed in 69 critically ill patients for the following indications: endocarditis (43%), embolic source (13%), hypotension (10%), mitral regurgitation (10%), left ventricular function (6%), aortic dissection (4%), prosthetic valve dissection (4%), and other (10%). Findings were unexpected in 21 of 83 studies and led to a change in management in 17%. On the basis of the results of TEE, 22% of patients had further evaluation by a more invasive technique, and 19% of patients had surgical intervention without further study. No significant complications attributable to TEE were noted. We conclude that TEE is a safe and useful diagnostic technique with fairly broad applications in the critical care setting.

Adolescent↗
PubMedDate not supplied

Right ventricular diastolic filling: evaluation with velocity-encoded cine MRI.

Abnormal flow velocity curves across the tricuspid valve (TV) and in the superior vena cava have been described in patients with abnormal right ventricular (RV) relaxation or restriction and with pericardial diseases by means of Doppler echocardiography. In this study, various imaging planes and strategies of velocity-encoded cine (VEC) MR for measurement of peak E and peak A velocities and the E/A ratio across the TV were evaluated and compared to Doppler measurements in 10 normal volunteers. In addition, VEC-MR velocity measurements were performed in the superior vena cava. Peak E and peak A velocities derived from three-dimensional VEC-MR phase images were slightly higher than velocities derived from two-dimensional VEC images. Higher velocities were measured by VEC-MR in the vertical long-axis plane compared with the horizontal long-axis plane. Excellent correlations (r > 0.89) were found between E/A ratios derived by VEC-MR and Doppler echocardiography. The interobserver variability for VEC-MR measurements was in the range of 2%. The VEC-MR depicted normal superior vena cava velocity curves in every volunteer. These results indicate that VEC-MR may offer a highly reproducible means of assessing abnormal filling properties of the RV.

Adult↗
PubMedDate not supplied

Setting up a collaborative care plan.

This article describes the creation of a collaborative care plan in a paediatric day surgery unit. The process of developing and using this document encourages collaborative care delivery and improves relationships between healthcare workers.

Algorithms↗
PubMedDate not supplied

Goodpasture's syndrome mimicking idiopathic pulmonary hemosiderosis.

A patient initially diagnosed by clinical findings and pulmonary biopsy as suffering from idiopathic hemosiderosis was subsequently proven by renal biopsy and serologic assay to have Goodpasture's syndrome with minimal renal alterations. The authors speculate on the relationship of these two complex disorders.

Adult↗
PubMedDate not supplied

Noninvasive assessment of the pulmonary artery pressure response to exercise after uncomplicated heart transplantation.

The pulmonary artery pressure response to exercise has been used as an index of cardiac reserve and frequently mirrors diastolic conditions. To define this response after orthotopic heart transplantation, we exercised 27 subjects on supine bicycle ergonometers. Stroke volume and pulmonary artery pressure were monitored with contrast-enhanced Doppler imaging. Study patients had undergone orthotopic heart transplantation. Seventeen patients were screened, and eight were subsequently determined by endomyocardial biopsy to be histologically free of acute cardiac allograft rejection. A control population of nonconditioned normal volunteers was also evaluated (heart transplant patients: n = 8, age = 45.7 +/- 7.3 years, seven men; normals volunteers: n = 10, age = 49.4 +/- 12.8 years, nine men; P = NS). Total exercise time and peak heart rate were reduced in heart transplant patients: 7.6 +/- 2.5 minutes, 123 +/- 4 beats/min versus normal volunteers: 16.2 +/- 4.5 minutes, 134 +/- 4 beats/min (P < 0.05). Change in stroke volume from baseline to peak exercise was greater in heart transplant patients: 29.9 +/- 4.6 ml versus normal volunteers: 3.9 +/- 5.7 ml (P < 0.01). No difference was observed in the pulmonary artery pressure response to exercise. In patients with uncomplicated heart transplantation a reduction in exercise capacity is shown; however, the pulmonary artery pressure response to exercise is comparable to normal subjects. A blunted heart rate response is observed, which is partially compensated by increases in stroke volume. These findings suggest that cardiac diastolic function is preserved and that denervation of the heart accounts for impaired exercise tolerance.

Adult↗