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Biomedical subjects

R Winter

Publications and source records attributed to R Winter.

At least 271 records · Page 15Linked to original sources
PubMed1986

The detection of intracranial carotid artery disease by continuous-wave Doppler sonography.

We have investigated 6,587 patients with directional continuous-wave (c-w) Doppler sonography of the carotid arteries during the last 33 months, and have developed criteria for the diagnosis of a significant increase in peripheral resistance of the internal carotid artery in conjunction with 1,671 retrograde brachial and direct carotid angiograms. We distinguished stenoses proximal (15 cases) and distal (4) to the origin of the ophthalmic artery, supraclinoid internal carotid artery occlusions (8), stenoses (2) and acute occlusions (10) of the middle cerebral artery. Stenoses in the carotid siphon (proximal or distal to the origin of the ophthalmic artery) of at least 60% reduction in lumen diameter showed a reduction of the relative end-diastolic flow velocity (modified Pourcelot's index) of more than 40%; additionally, stenoses proximal to the origin of the ophthalmic artery exhibited a variable alternating flow, or flow reversal, in the supratrochlear artery. Stenoses distal to the origin of the ophthalmic artery rarely revealed the theoretically expected increase in orthograde flow velocity in the supratrochlear artery. Stenoses of the middle cerebral artery consisting of more than atherosclerotic irregularities proved to be an exception. Supraclinoid occlusions of the internal carotid artery were reliably demonstrated by Doppler sonography. However, the majority of acute occlusions of the middle cerebral artery could not be detected by this means, probably due to anastomoses between the anterior and the middle cerebral arteries, which were detected by angiography. Thus, we believe that c-w Doppler sonography is a reliable tool to detect stenoses of the carotid siphon of more than 60% reduction in lumen diameter and and supraclinoid carotid artery occlusions.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial Occlusive Diseases↗
PubMed1986

[Doppler ultrasonic evaluation of the efficiency of extra-intracranial anastomoses].

We report on the results obtained by means of directional continuous-wave Doppler sonography in 33 patients with superficial temporal-to-middle cerebral artery anastomoses. Recurrent transient ischaemic attacks or a recent mild neurological deficit were considered as justification for bypass surgery in cases of angiographically proven occlusions of one or both internal carotids, severe intracranial carotid artery disease, or stenoses and occlusions of the M-1 segment of the middle cerebral artery. The efficiency of the anastomosis was evaluated by the modified Pourcelot indices (relative end-diastolic flow velocity) of the preauricular superficial temporal artery and of the bypass-supplying branch at the edge of the burr-hole. The influence of intermittent compression of the bypass-supplying branch on the modified Pourcelot index of the ipsilateral common carotid was used as a further criterion for sonographic evaluation. All efficient anastomoses, defined by a modified Pourcelot index of at least 0.20 at the edge of the burr-hole, exhibited an average reduction of 0.08 in the relative end-diastolic flow velocity in the common carotid during compression. In the 18 patients with unilateral occlusion of the internal carotid, bypass surgery was predominantly efficacious (by the above criterion) in those patients who showed a reduction in the sum of the modified Pourcelot indices of the remaining brain-supplying arteries of at least 10% as compared with age-matched controls. The subgroups of existing and absent collaterals through the ophthalmic artery did not show any differences with respect to the percentage of efficient anastomoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Pregnancy anamnesis and delivery in females with abnormalities of the internal genitalia].

The ability to deliver a living infant was examined in 65 women with genital malformations, in a retrospective clinical study. 87 deliveries resulted, the overall abortion rate was 35%. 44% of pregnancies proceeded without any complications, in 46% the first pregnancy led to the birth of a living child. Classification of genital malformations displayed a dominancy of severe forms like uterus duplex, bicornis and septus. Comparison of severe and mild uterovaginal anomalies revealed no significant differences concerning course and duration of pregnancy, birth weight and perinatal outcome of the newborn, whereas frequency of operative deliveries raised significantly in the group of severe defects, Apgar scores after one minute appeared significantly lower. A remarkable accumulation of breech presentations (50%) in combination with increased obstetric complications led to 82% of operative deliveries. The birth of 58% of boys caused a shifting of the sex ratio. The perinatal offspring was encouraging; 73% of the newborn could leave the clinic together with their mothers.

Abortion, Habitual↗
PubMed1986

[Topography of the corneal endothelium following surgical trauma].

In a prospective study preoperative and postoperative endothelial cell densities were determined after intracapsular cataract extraction with and without implantation of intraocular lenses. There was a characteristic disparity in cell densities measured at different points--near the corneal wound, at the center, and below the center. The cell loss measured near the corneal wound is partly compensated for by elongation of the cells below the center. Consequently, the cell loss is not only made good in the immediate postoperative period; cell migration also continues for prolonged periods of time until homogeneity of the cell pattern is almost completely restored.

Cataract Extraction↗
PubMed1986

[Side effects of YAG laser treatment].

In enucleated pig eyes endothelial cell damage was demonstrated after YAG laser coagulation. The extent of the damage can be correlated to the distance between the laser focus and the endothelium, and to the energy. Similar effects and correlations can be demonstrated on intraocular implant lenses in an experimental model.

Animals↗
PubMed1986

Evaluation of sperm motility by laser--Doppler-spectroscopy in an in-vitro fertilization programme.

Laser-Doppler-spectroscopy represents a new, fast and reliable technical method for the assessment of several parameters of sperm motility including the percentage of spermatozoa which are motile, and mean spermatozoal velocity. Serial measurements of these parameters in routine andrological work permit standards for four main spermiogram diagnoses to be established. Laser-Doppler-spectroscopy was used to verify alterations in the motility of spermatozoa after capacitation in an in-vitro fertilization programme. An enhancement of 16% for total sperm motility and 36% for mean spermatozoal velocity could be observed. The results of in-vitro fertilization after various spermigram diagnoses, combined with long-term observations of mean spermatozoal velocity, may be considered as another step towards the elucidation of sperm-oocyte interactions. Comparisons between the development of embryos revealed significant differences between normo- and asthenozoospermic men versus oligozoospermic patients.

Fertilization in Vitro↗
PubMed1986

The effect of systemic beta-2 adrenergic agonist therapy on the pulmonary hypertensive response to chronic hypoxia in rats.

Chronic hypoxia produces polycythemia, pulmonary hypertension, muscularization of peripheral pulmonary arteries, and right ventricular hypertrophy. The present study was designed to investigate the effects of systemic administration of a beta-2 adrenergic agonist on these responses. Male Wistar rats (9 or more in every group) were maintained in room air or 10% oxygen for 28 days. In the first experiment, they were treated with albuterol at various doses (0.05 mg/kg, 0.1 mg/kg, 0.5 mg/kg) twice during exposure to intermittent hypoxia (10 h/day). In the second experiment, rats were treated with albuterol 2.5 mg/kg subcutaneously twice daily during continuous hypoxia. Control animals in normoxia and hypoxia received 0.1 ml saline at equivalent times. All hypoxic groups developed polycythemia, significantly increased right ventricular systolic pressure, and right ventricular hypertrophy. At doses of albuterol that did not produce cardiac hypertrophy in normoxia, treatment had no effect on the development of right ventricular hypertrophy. With lower doses of albuterol in hypoxia, there was a trend towards an increase in hematocrit, but overall this did not reach significance. Treatment with high dose albuterol in continuous hypoxia significantly increased the hematocrit and enhanced the remodeling of the pulmonary vasculature (Hematocrit: saline-treated, 57.7 SEM 1.9; albuterol-treated, 63.4 SEM 1.7; p less than 0.05. Percentage of thick-walled peripheral vessels: saline-treated, 19.4 SEM 0.60; albuterol-treated, 22.7 SEM 0.85; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1986

[Thrombolytic therapy with ultra-high doses of streptokinase].

Two pilot studies were carried out in patients suffering from acute myocardial infarction. They received high doses of streptokinase and acylated streptokinase-plasminogen activator complex intravenously as a bolus injection. Furthermore, the possibility of using streptokinase bolus therapy was examined in patients with acute vascular occlusion. Due to the limited number and the heterogenicity of cases the results obtained in patients with acute myocardial infarction are to evaluate with some reservation. In patients with acute vascular occlusion streptokinase bolus therapy at high doses proved to be a promising alternative to the conventional therapy.

Coronary Angiography↗
PubMed1986

[Urodynamic and roentgenologic findings before and following complex physical therapy of urinary incontinence in the female].

In 42 patients complaints following therapy have been correlated to the pretherapeutic urodynamic findings and in 58 patients pre- and posttherapeutic urometric and X-ray findings have been compared independent from subjective result in oder to have objective parameters for the effectivity of conservative treatment of urinary incontinence. The best results could be achieved, if in the starting urometry the pressure transmission was bad and the dosing pressure of the urethra in rest adequate to the age. In analogy about identic urethral closing pressure in rest, but significant increase of the functional urethral length and a better pressure transmission in a sitting position could be found. Good results of conservative treatment on urge incontinence symptomatology could be derived from increasing bladder capacity and compliance. Against it a posttherapeutic increase of urinary incontinence signs by training-effects of exercise therapy has to be stated in the comparison of X-rays. Altogether the high rate of 63 per cent curing and 20 per cent improvement could not be detached sufficiently by urometric and radiography findings. This discrepancy has been discussed.

Female↗
PubMed1985

Doppler sonography in basilar artery occlusion.

We have investigated 6,972 patients with directional continuous-wave Doppler sonography within the last three and a half years, and have derived criteria for the sonographic diagnosis of basilar artery occlusion or tight stenosis in conjunction with 1,071 retrograde brachial angiograms. By sonographic patterns, we have suspected obstruction of the basilar artery or of both distal vertebral arteries in nine cases. Either bilateral sonographic silence or the absence of a diastolic flow component of the vertebral arteries served as criteria in the sonographic evaluation. Angiography of the vertebro-basilar system, performed in eight cases, showed near or complete occlusion in the distal vertebrals or in the proximal basilar artery. Degrees of stenosis less than an 80 percent reduction in lumen diameter could not be detected sonographically. Two further basilar artery occlusions were detected by means of angiography despite negative Doppler sonography: one of these patients showed an extensive collateral circulation between the posterior inferior and the superior cerebellar arteries, and one patient had an occlusion only of the middle and rostral thirds of the basilar artery, the proximal third and the anterior inferior cerebellar arteries being widely patent. Thus, we believe that directional CW Doppler sonography is very useful in the diagnosis of near or complete occlusion of both distal vertebral arteries or of the proximal basilar artery.

Angiography↗
PubMed1985

[Doppler sonography in intracranial circulation disorders of the internal carotid artery. A comparative Doppler sonography-angiography study].

During the past 33 months we have investigated 6,587 patients using directional continuous-wave Doppler sonography of the carotid arteries. On the basis of 1,671 retrograde brachial and direct carotid angiograms we have developed criteria for demonstrating a significant increase in the peripheral resistance of the internal carotid artery. We distinguished stenoses proximal (15 cases) and distal (4) to the origin of the ophthalmic artery, supraclinoid internal carotid artery occlusions (8), stenoses (2) and obliterations (10) of the middle cerebral artery that developed suddenly. Stenoses in the carotid siphon (proximal or distal to the origin of the ophthalmic artery) showed a reduction of more than 40% in the relative end-diastolic flow velocity (modified Pourcelot's index); in addition, stenoses proximal to the origin of the ophthalmic artery exhibited an alternating flow, or flow reversal, in the supratrochlear artery to a variable extent. Stenoses distal to the origin of the ophthalmic artery only rarely revealed the increase in orthograde flow velocity that had been theoretically expected in the supratrochlear artery. Stenoses of the middle cerebral artery exceeding the extent of atherosclerotic irregularities proved to be an exception. Supraclinoid obliterations of the internal carotid artery were reliably demonstrated by Doppler sonography. However, the reliably demonstrated by Doppler sonography. However, the majority of the occlusions of the middle cerebral artery that developed suddenly could not be detected by this means, probably due to anastomoses between the anterior and middle cerebral arteries, which were detected by means of angiography. Thus, we believe that continuous-wave Doppler sonography is a reliable tool for detecting stenoses of the carotid siphon of more than 60% reduction in lumen diameter as well as supraclinoid carotid artery occlusions. Resistance to the cerebral blood flow that is located more peripherally cannot be diagnosed reliably by this method.

Brain Ischemia↗
PubMed1985

[Diagnosis and therapy of fetal kidney and urinary tract malformations].

Of 23 patients with abnormal prenatal sonographic findings 17 also showed malformations of the kidneys and urinary tract in the postpartal period. Although even minor abnormalities could be detected by antenatal ultrasound, the identification of the abnormal findings was not possible in every case. Diagnostic problems arose in 8 foetuses showing mild dilatation of the collecting system, since it was not possible to distinguish between functional dilatation and dilatation from vesicoureteral reflux or minimal ureteral obstruction. Difficulties in identification of large malformations also occurred in 3 other patients, if the first sonographic examination was performed in a late stage of pregnancy, so that no follow-up of the sonographic picture was possible. In one of these children a huge right-sided multicystic kidney resulted in compression of the contralateral ureter with hydronephrosis, damaging the other kidney. Early delivery should, therefore, be considered in all children showing large cystic abdominal masses and no identifiable normal kidney, so that adequate obstetric treatment of these patients can be initiated in time.

Female↗
PubMed1985

[Needs and technical prerequisites of an improved supply of donor material for penetrating keratoplasty].

The supply of donor material for keratoplasty is still considered a problem in many clinics. Preservation of donor tissue makes it possible to improve material selection. As far as the grafting of typed corneas is concerned, corneal organ culture offers a valuable time interval for planning the operation. In these preservation techniques the transplanted tissue is trephined from the endothelial side. With an optimal trephining technique the number of viable endothelial cells transplanted can be increased.

Corneal Transplantation↗