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Biomedical subjects

B Engel

Publications and source records attributed to B Engel.

52 records · Page 3Linked to original sources
PubMed1989

Cell density of human lens epithelium in women higher than in men.

Flat preparations of the central lens epithelium in 181 human donor eyes, 120 male, 61 female, were used to determine epithelial cell density. Donor age ranged from 13 to 91 years. A similar linear age-dependent decrease of cell density was found in both sexes. In addition, the epithelial cell density was significantly higher in females. The age-adjusted mean cell density in males was 5008.6 cells/mm2, in females 5780.6 cells/mm2. A similar sex difference had been found before in lens epithelium of human cataracts. The cause and significance of this observation are unknown.

Adolescent↗
PubMed1987

Feedback regulation of gonadotropic hormone secretion in neonatal pigs.

The effect of castration and of administration of charcoal-treated porcine follicular fluid (pFF) containing inhibin-like activity on plasma concentration of gonadotropic hormones was studied in neonatal pigs. Plasma follicle-stimulating hormone (FSH) concentration averaged 25.1 +/- 1.5 ng/ml (mean +/- SEM) in 1-wk-old females and gradually declined to 20.2 +/- 0.7 ng/ml 6 wk later. Ovariectomy did not significantly influence plasma FSH concentration. In males, concentration averaged 8.0 +/- 0.7 ng/ml before castration but rose significantly within 2 days after castration. Injection of luteinizing hormone-releasing hormone (LHRH) did not influence plasma FSH concentrations in intact males, but did in females and in 7-wk-old males castrated at 1 wk. Plasma luteinizing hormone (LH) concentrations in 1-wk-old females (2.2 +/- 0.4 ng/ml) gradually declined and were not influenced by castration. Concentrations of plasma LH in 1-wk-old male piglets (2.8 +/- 0.7 ng/ml) were not significantly influenced by castration within 2 days but were significantly higher 6 wk later. LHRH induced a significant rise in plasma LH concentrations in all animals. Injection of pFF resulted in a decline of plasma FSH concentrations in intact and castrated males and in intact females, but did not influence plasma LH concentrations. These data demonstrate a sex-specific difference in the control of plasma FSH, but not in plasma LH concentration in the neonatal pig. Plasma FSH concentrations, but not plasma LH concentrations, are suppressed by testicular hormones in 1-wk-old piglets. Plasma FSH concentrations can be suppressed in both neonatal male and female pigs by injections of pFF.

Aging↗
PubMed1985

Inotropic selectivity of salbutamol and terbutaline in anaesthetised, areflexic dogs.

The cardiovascular effects of the selective beta 2-adrenoceptor agonists salbutamol and terbutaline have been evaluated in anaesthetised, areflexic dogs. The preparation was designed to reduce the effects of changes in cardiac function mediated via reflex responses to changes in blood pressure. The effects of the selective beta 2-adrenoceptor agonists on heart rate, hindlimb blood flow, left ventricular pressure, max dP/dt and (dP/dt)/IIT (integrated isometric tension) were compared to those of isoprenaline, while blood pressure was held constant. All three drugs produced dose-dependent increases in heart rate, myocardial contractility and iliac blood flow. When equiactive inotropic doses of isoprenaline and salbutamol were compared, salbutamol produced a significantly lower chronotropic effect. A similar inotropic selectivity was found when terbutaline was compared to isoprenaline. beta 2-Adrenoceptor blockade abolished this selectivity. It is concluded that, in the absence of autonomic reflex activity, the beta 2-selective adrenoceptor agonists are relatively selective inotropic stimulants.

Albuterol↗
PubMed1985

[Vecuronium: onset of effect and intubation conditions in comparison to pancuronium and suxamethonium].

The onset of neuromuscular blockade following the i.v. injection of vecuronium and pancuronium 0.05, 0.08 or 0.1 mg/kg and suxamethonium 0.5 or 1.0 mg/kg was studied in 304 patients during induction of anaesthesia by means of the compound action potential derived from the adductor pollicis muscle, which was indirectly stimulated via the ulnar nerve. The intubation conditions 1-5 min after injection were assessed using a scoring system related to ease of laryngoscopy, movement of vocal cords and coughing, and reflex movements of extremities. Development of motor blockade was time- and dose-dependent. After administration of 0.1 mg/kg vecuronium, the actual maximum effect (more than 90% block) was established within 4 min; after 0.1 mg/kg pancuronium within 6 min and after 1.0 mg/kg suxamethonium within 2 min. Intubation conditions improved with time. After 0.1 mg/kg vecuronium atraumatic intubation was possible within 2 min and after 0.1 mg/kg pancuronium within 4 min. Following 1.0 mg/kg suxamethonium, optimum intubation conditions were achieved within 1 min. Although suxamethonium acts the fastest and tracheal intubation can be achieved within 0.5-1.0 min, its use involves certain side effects and disadvantages. Vecuronium acts considerably faster than pancuronium and good or excellent intubation conditions are present within 2 min. Suxamethonium is no longer the muscle relaxant of choice for intubation except for crash intubation, e.g., in patients with a full stomach.

Adult↗
PubMed1983

Relative inotropic and chronotropic activity of beta-adrenoceptor stimulants in anaesthetised, areflexic dogs.

The use of different methods of measuring contractility and the effects of cardiovascular reflexes are among the factors which complicate the assessment of selective inotropic activity of beta-adrenoceptor agonists. The effects of dobutamine, prenalterol, noradrenaline and isoprenaline on heart rate, iliac blood flow, left ventricular pressure, max dP/dt and (dP/dt) divided by IIT (integrated isometric tension) were evaluated in anaesthetised dogs in which the hearts were denervated and blood pressure held constant. All the drugs caused dose-dependent increases in heart rate and contractility. The relative chronotropic and inotropic activity of each agonist was evaluated. At most doses studied the agonists exerted similar chronotropic and inotropic activity when compared to the non-selective agonist isoprenaline. It is likely that the inotropic selectivity observed with prenalterol and dobutamine in previous studies depends on factors other than direct drug action.

Adrenergic beta-Agonists↗
PubMed1975

Steroid hormone receptors in human breast cancer and clinical correlations.

Human breast cancer was studied by in vitro techniques on tissue slices and extracts for a specific binding of estradiol and dihydrotestosterone. Estradiol receptors were found in 50 percent of patients in the premenopausal group and in 47 percent of patients in the postmenopausal group. The incidence of receptors in patients with metastatic disease was 32.5 percent. In 18 of 35 patients who were positive for receptor sites a remission was observed after a variety of endocrine treatment regimens. In contrast only 3 patients out of 43 with a negative binding pattern responded to treatment with nafoxidine for a very short time. The best correlation was found in the ovariectomized group. Between the responders and the nonresonders there is no difference in the quantitative receptor content. The same is valid in view of the duration of the remission.

Adult↗
PubMedDate not supplied

Renal dietitians: setting standards in care.

The professional body for State Registered Dietitians, the British Dietetic Association (BDA), has been instructed by the NHS Executive Clinical Audit Unit to produce and validate national dietetic standards across all clinical specialties. The BDA have so far produced eight National Professional Standards (Table 1) that can be used as a framework for developing local standards.

Dietetics↗