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Biomedical subjects

W Beck

Publications and source records attributed to W Beck.

At least 109 records · Page 6Linked to original sources
PubMed1980

[Postnatal development of the ovarian surface epithelium (author's transl)].

The peritoneal epithelium of the ovary on one to 49 day-old albino rats was investigated using light and electron microscopy and ultracytochemical methods. The aim of the present work was to clarify the role of the epithelium in the development of oocytes and follicles. At birth the epithelial covering of the ovary is stratified. This condition is associated with oocytes embedded in the surface epithelium. With the light and electron microscope superificial and deeper cells can be seen. The superficial layer exhibits wide intercellular spaces apical bounded by gap junctions. With increasing age these spaces become filled with homogeneous electron dense material. The basal cells have numerous cytoplasmic protrusions and interdigitations. Moreover from the surface epithelium cortical cords, containing clusters of oocytes, reach into the ovarian stroma. In every epithelial cell some lysosomes and pinocytotic vesicles are present, the latter preferably located under the plasmalemma of superficial cells lining the intercellular spaces. The basal cytoplasm of the deeper cells exhibit granules with an electron dense content. Using ultracytochemical methods we have identified most of them as lysosomes too. The greatest amount of granules is found in the 2nd week of life, then they decrease in number with increasing age. The observations have revealed evidence for intensive interactions between peritoneal cavity, surface epithelium, intercellular spaces, and tunica albuginea (including processes of resorption and secretion). The epithelial covering obviously plays a nutritive role for oocytes and the ovarian cortex. During the 2nd week of life the surface epithelium becomes reduced to a simple epithelium as the oocytes migrate into the ovarian cortex. At the same time the epithelium becomes separated from the oocyte-bearing cords by a definite tunica albuginea. The epithelial cords disintegrate leaving primordial follicles. These observations suggest, that the follicle epithelial cells are derived from the ovarian surface epithelium and the epithelial cords.

Aging↗
PubMed1979

Associations between atopic diseases and the polymorphic systems ABO, Kidd, Inv and red cell acid phosphatase.

In 239 German patients with atopic conditions (atopic dermatitis, hay fever, allergic rhinitis, bronchial asthma, and acute urticaria) the phenotype and gene distribution of 15 genetic blood polymorphisms (ABO, MNSs, rhesus, P, Kell, Duffy, Kidd, Hp, Gc, Gm, Inv, aP, PGM1, EsD, and 6-PGD) were analyzed and compared with those in 151 selected controls (individuals clinically free of allergic conditions and without allergy in the family history). The incidence of blood group antigens A and B was somewhat higher in patients than in controls. These observations are in accordance with the results of previous studies in other populations. In addition, our observations favor the hypothesis that there are also associations between the phenotypes Jk (a-b+), Inv(1) and red cell acid phosphatase aP A and aP AP on the one hand and atopic disposition on the other. The possible reasons for these associations are discussed.

ABO Blood-Group System↗
PubMed1979

Prolactin-producing pituitary adenoma in a 9 year old boy.

A boy aged 9 years and 8 months was evaluated for headache and an enlarged sella. His neurological status and visual fields were normal. After injection of radiographic contrast agent, computerized axial tomography showed evidence of an intrasellar tumor. The most striking endocrine abnormalities were growth hormone insufficiency after arginine infusion and after insulin-induced hypoglycemia, and excessively elevated prolactin levels ranging between 1220 ng/ml and 1560 ng/ml. A slightly granulated, acidophilic pituitary adenoma was selectively removed by the trans-sphenoidal approach. The function of the anterior pituitary improved post-operatively. Growth hormone secretion after insulin-induced hypoglycemia returned to normal, and the basal serum prolactin levels decreased, but are still three times higher than normal.

Adenoma, Acidophil↗
PubMed1979

Differential function of the phosphoglucomutase isozymes PGM1 and PGM2.

A total of 13 metabolites thought to be possibly inhibitory were tested for their influence on PGM isozyme activities, each at several different concentrations. The analysis of statistical significance was based on enzyme activities obtained by densitometric measurements of starch gels. Five of the substances were found to inhibit PGM activity, three of which definitely and a further one probably led to a significantly stronger inhibition of the isozymes of the PGM2 locus than of PGM1 isozymes. They are (1) fructose-1,6-diphosphate, (2) adenosine triphosphate, (3) citrate, and (4) possibly 2,3-diphosphoglycerate. Thus, PGM1 isozymes proved to function better in hard or perhaps marginal metabolic conditions. Related evolutionary aspects are discussed.

Adenosine Triphosphate↗
PubMed1979

Annual rhythms of luteinizing hormone, follicle-stimulating hormone, prolactin and testosterone in the serum of male rhesus monkeys.

Six male rhesus monkeys were kept under rigidly controlled conditions for 1-2 years. During August of the first year a thyrotrophin releasing hormone (TRH) test was performed on each of the monkeys by giving 10 microgram TRH as a bolus injection. Significantly increased serum prolactin levels occurred 15 min after the injection. After a training period of 2 months, during which blood samples were collected every other day by puncture of the saphenous vein, blood was collected three times a week for 14 months. Serum levels of prolactin, LH, FSH and testosterone were measured by radioimmunoassay. Mean serum prolactin levels increased significantly during June, July and August in all six animals. Peak levels were observed in August and September and then levels declined gradually to reach a minimum in April and May. Mean serum testosterone levels closely paralleled the annual pattern of prolactin. Mean serum LH levels significantly decreased during the time when mean serum prolactin and testosterone levels were increasing and they increased again at the time of decreasing mean prolactin levels, i.e. mean serum LH and prolactin were negatively correlated. In individual monkeys, however, a rigid negative correlation between serum prolactin and LH could not be demonstrated. Mean serum FSH levels did not change significantly.

Animals↗
PubMed1978

Use of a double atrial-triggered standby pacemaker system for a patient with a biventricular bypass heterotopic cardiac homograft.

In a patient who had a biventricular bypass heterotopic cardiac homograft a double atrial-triggered standby pacemaker system was implanted to allow sequential atrial pacing of both hearts. The system design permitted either the recipient or the donor heart to dictate the rate of its fellow, depending on which heart had the faster spontaneous sinus rate at any time. Alternative methods for achieving sequential pacing are discussed.

Adult↗
PubMed1978

Closure of the complicated patent ductus arteriosus.

A technique for closure of the complicated ductus arteriosus is described which has proved both simple and safe. The technique embodies the use of profound hypothermia, low flow, and direct suture of the pulmonary end of the ductus arteriosus through a pulmonary arteriotomy. No operative deaths have occurred among 4 patients so treated, and no complications from air embolism or hemorrhage have been encountered.

Blood Flow Velocity↗
PubMed1978

Results after mitral valve replacement with cloth-covered Starr-Edwards prostheses (models 6300, 6310/6320, and 6400).

The actuarial survival and thromboembolic rates for the three types of cloth-covered Starr-Edwards mitral prostheses, models 6300, 6310/6320, and 6400 followed 6, 5, and 2 years, respectively, were not significantly different throughout the years they were followed. The combined cumulative survival and thromboembolic proportion at 5 years for these prostheses were 71 and 66 per cent, respectively. The thromboembolic rates were not different in the following two groups: (a) 238 patients receiving anticoagulants, and (b) 52 patients who had discontinued or who were not receiving anticoagulants. Four patients thrombosed their mitral prostheses. Another 8 per cent had class 3 symptoms after operation, which were attributed to myopathic or restrictive left ventricular dysfunction or other valvular disease.

Adult↗
PubMed1978

Double outlet right ventricle: clinical and anatomical spectrum.

Thirty-two patients with double outlet right ventricle (DORV) were studied between 1960 and 1976. Associated congenital defects frequently compounded the difficulty of clinical diagnosis. Cardiac catheterisation was performed in 27 patients, and the ventriculograms were studied with particular regard to the relative positions of the great vessels to each other and to the ventricular septal defect. These relationships determine which corrective operation is possible. Correction has been performed in 12 patients with a perioperative mortality of 25%. Although mitral-aortic discontinuity was demonstrated in all cases, consideration of the anatomical spectrum included in the term DORV suggests that discontinuity is not an essential feature. In common with other clinical data and in contrast with necropsy studies, none of our patients was found to show the normal relationship of the great vessels to each other, in which the aorta lies posterior and to the right of the pulmonary artery. The reason for this difference between the clinical and necropsy findings is not apparent. A similar disparity was shown with regard to pulmonary stenosis, which was demonstrated at catheterisation in 68% of the 27 patients (mean gradient 68 +/- 3 mmHg), in contrast with incidences of 18% and 25% in recent necropsy series. Patients in the necropsy studies were frequently neonates or infants, in whom death may have been the result of intractable cardiac failure secondary to excessive pulmonary blood flow. In older patients without pulmonary stenosis and with pulmonary hypertension, frequent observation is imperative so that surgical treatment can be instituted before the development of irreversible pulmonary vascular disease.

Adolescent↗
PubMed1978

Hemodynamic assessment of Lillehei-Kaster tilting disc aortic and mitral prostheses.

Twenty-six patients with Lillehei-Kaster prosthetic heart valves, 15 with aortic and 11 with mitral valves, were catheterized to assess their hemodynamic performance. The calculated effective orifice areas were linearly related to but always less than their actual orifice areas. There was no significant difference in the effective orifice area of the mitral or aortic prostheses of similar size. The aortic prosthesis with an annulus diameter of 21 mm. was found to have a mean effective orifice area of 0.77 sq. cm. Our catheter studies have demonstrated no hemodynamic advantages of the Lillehei-Kaster aortic and mitral prosthetic valves over prosthetic valves.

Aortic Valve↗
PubMed1977

Results of valve replacement with the Lillehei-Kaster disc prosthesis.

The results of valve replacement in 150 patients with Lillehei-Kaster aortic and mitral prostheses followed for 20 to 40 months are reviewed. Actuarial analysis showed 78 per cent cummulative thromboembolic-free rate three years following mitral valve replacement and 89 per cent following aortic valve replacement. Five patients had a total of six episodes of mitral valve thrombosis despite anticoagulant therapy. Early detection of mitral valve obstruction was difficult because a mid-diastolic murmur and absence of an opening sound was frequently encountered in normally functioning prostheses. Hemodynamic results assessed clinically in patients with nonthrombosed prostheses were satisfactory.

Aortic Valve↗
PubMed1977

Coronary heart disease in marathon runners.

Six highly trained marathon runners developed myocardial infarction. One of the two cases of clinically diagnosed myocardial infarction was fatal, and there were four cases of angiographically-proven infarction. Two athletes had significant arterial disease of two major coronary arteries, a third had stenosis of the anterior descending and the fourth of the right coronary artery. All these athletes had warning symptoms. Three of them completed marathon races despite symptoms, one athlete running more than 20 miles after the onset of exertional discomfort to complete the 56 mile Comrades Marathon. In spite of developing chest pain, another athlete who died had continued training for three weeks, including a 40 mile run. Two other athletes also continued to train with chest pain. We conclude that the marathon runners studied were not immune to coronary heart disease, nor to coronary atherosclerosis and that high levels of physical fitness did not guarantee the absence of significant cardiovascular disease. In addition, the relationship of exercise and myocardial infarction was complex because two athletes developed myocardial infarction during marathon running in the absence of complete coronary artery occlusion. We stress that marathon runners, like other sportsmen, should be warned of the serious significance of the development of exertional symptoms. Our conclusions do not reflect on the possible value of exercise in the prevention of coronary heart disease. Rather we refute exaggerated claims that marathon running provides complete immunity from coronary heart disease.

Adult↗