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Biomedical subjects

W W Meyer

Publications and source records attributed to W W Meyer.

At least 19 recordsLinked to original sources
PubMed2001

Local recurrent cancer after radical prostatectomy and incontinence. Is the artificial urinary sphincter a useful therapeutic option?

OBJECTIVE: The artificial sphincter AMS AS 800 is the treatment of choice in postprostatectomy urinary incontinence. However, when the incontinence is combined with a local tumour recurrence, the insertion of an artificial sphincter may pose a problem. Tumour mainly localised at the site of the anastomosis could cause problems with the insertion of the cuff. It is also questionable whether this elaborate and expensive operation is appropriate in patients with a progressive carcinoma. MATERIALS AND METHODS: The charts of 220 patients who received a bulbar artificial sphincter between 1986 and 1996 were reviewed. Five patients were selected who suffered from simultaneous urinary incontinence and local recurrence of prostate cancer. The follow-up of these patients was between 18 and 70 months. RESULTS: In all 5 patients the implantation of the artificial sphincter at the bulbous urethra could be performed without any complications. All patients were continent during follow-up. Two changes of the cuff were necessary due to tissue shrinkage of the urethra below the cuff. One patient, 2 years after local excision of recurrent prostate cancer, was found, during implantation, to have a macroscopically inconspicuous though histologically tumour-infiltrated area. In the follow-up 5 years after the implantation his prosthesis is still working well. CONCLUSIONS: Even with local recurrence of prostatic carcinoma after radical prostatectomy, the patients' prognosis 'quo ad vitam' is not bad. The follow-up of patients proves that they profit from implantation of an artificial sphincter in terms of better quality of life. Sphincter-related complications are not more frequent than in comparable groups of patients without local recurrence.

Aged↗
PubMed2001

The Gaussian derivative model for spatial-temporal vision: I. Cortical model.

How do we see the motion of objects as well as their shapes? The Gaussian Derivative (GD) spatial model is extended to time to help answer this question. The GD spatio-temporal model requires only two numbers to describe the complete three-dimensional space-time shapes of individual receptive fields in primate visual cortex. These two numbers are the derivative numbers along the respective spatial and temporal principal axes of a given receptive field. Nine transformation parameters allow for a standard geometric association of these intrinsic axes with the extrinsic environment. The GD spatio-temporal model describes in one framework the following properties of primate simple cell fields: motion properties, number of lobes in space-time, spatial orientation. location, and size. A discrete difference-of-offset-Gaussians (DOOG) model provides a plausible physiological mechanism to form GD-like model fields in both space and time. The GD model hypothesizes that receptive fields at the first stage of processing in the visual cortex approximate 'derivative analyzers' that estimate local spatial and temporal derivatives of the intensity profile in the visual environment. The receptive fields as modeled provide operators that can allow later stages of processing in either a biological or machine vision system to estimate the motion as well as the shapes of objects in the environment.

Animals↗
PubMed2001

The use of a lithoclast probe for ureterorenoscopic coagulation of bleeding ureteral cancer.

PURPOSE: We describe use of the lithoclast device, normally used for electrohydraulic stone fragmentation, for safe ureteroscopic intraureteral coagulation of a bleeding tumor. MATERIALS AND METHODS: Intraureteral ureteroscopic coagulation of a bleeding transitional cell carcinoma was performed in an 86-year-old high risk patient. A 0.8 mm. probe of the lithoclast device was connected to high frequency current. To avoid short circuit to the ureteroscope the probe was covered with a standard 5Fr ureteral catheter, which served as a perfect isolator. RESULTS: The bleeding intraureteral tumor was coagulated successfully under direct vision. CONCLUSIONS: The lithoclast probe in combination with a standard ureteral catheter can be used for intraureteral coagulation of bleeding tumors. It is an inexpensive device that is often available in nonuniversity departments.

Aged↗
PubMed1994

Efficacy, risks, and limits of extracorporeal shock wave lithotripsy for salivary gland stones.

Stones of the salivary glands may cause recurrent swelling, ascending inflammation, and colic-like pain. Previously, in order to get rid of these stones, the gland usually had to be removed surgically in spite of the associated risks to adjacent structures, especially the facial nerve. We treated 104 salivary gland stones in patients 14 to 78 years old using the Storz Modulith SL 10 lithotripter. Each session (average 3.6 per patient) consisted of 1000 impulses at 2 Hz and 16 to 18 kV. No anesthesia was required. Earplugs were applied to patients being treated for parotid gland stones. With the aid of SWL and drug-induced salivation, 17 (59%) of the patients with parotid gland stones and 42 (56%) of those with submandibular gland stones obtained either total stone clearance or sufficient fragmentation to permit spontaneous passage. Four patients required surgery. The remaining patients are still being treated. The noninvasive SWL for salivary gland stones is noninvasive and painless and has a considerable success rate. It can be performed on an outpatient basis.

Acute Disease↗
PubMed1994

[A Calcutript-Lithoclast comparison: electrohydraulic lithotripsy versus acoustic pressure wave lithotripsy. An in vitro study on chalk cubes].

Intracorporeal lithotripters are available in nearly all urological institutions. The authors compared the CALCUTRIPT made by K. Storz Co. and the Swiss LITHOCLAST in in vitro studies. No major difference in the efficacy of disintegration was observed after subjecting chalk cubes to the two modalities. Human tissue of the renal pelvis, ureter and bladder was exposed to both energy-sources. In the case of the electrohydraulic shock wave the authors found complete rupture of all three layers of the ureteric wall after exposure even with low energy, while tissue perforation was observed in only one of 72 tissue samples exposed to the LITHOCLAST. The authors recommend the LITHOCLAST because of its minimal invasiveness for the treatment of calculi especially in the ureter.

Adult↗
PubMed1992

[Functional structures of the aorta as a predilection area of the earliest atherosclerotic changes].

Marked lipid deposits selectively localized in the grooves of so-called aortic functional structures were found in a 5-month-old infant who died of rapidly progressing crescentic glomerulonephritis. A prominent nephrotic syndrome comprising hypercholesterolemia and triglyceridemia was present and led to extensive lipid infiltration of the aortic intima. Development of the intimal lesions was probably enhanced by hypertension found in final phase of the illness. Spontaneously enhanced permeability of the intima in the "grooves" and a special constellation of haemodynamic forces along the functional structures were probably responsible for the peculiarly selective localization of lipid deposits that has so far not been described in the literature.

Aorta, Abdominal↗
PubMed1989

Omeprazole (20 mg o.m.) versus ranitidine (150 mg b.d.) in duodenal ulcer healing and pain relief.

The object of this double-blind, multicentre study was to compare duodenal ulcer healing rates after 2 to 4 weeks of treatment with either 20 mg omeprazole o.m. or 150 mg ranitidine b.d. One hundred and eighty-one patients were randomized: 91 received omeprazole and 90 received ranitidine. In a per protocol analysis at 2 weeks, 63% of the patients were healed on omeprazole and 65% of the patients were healed on ranitidine (N.S.); at 4 weeks 91% were healed in the omeprazole group and 96% were healed in the ranitidine group. There were no differences in ulcer symptom relief between the two groups. There were no significant changes in laboratory values in either of the groups. Adverse events were few and mainly mild and transient. We conclude that both omeprazole (20 mg o.m.) and ranitidine (150 mg b.d.) result in rapid, ulcer healing rates.

Adult↗
PubMed1986

[Lithotripsy of intrahepatic gallstones].

After placement of a T-drain near some intrahepatic gallstones their fragmentation was successfully accomplished by extracorporeal shock-wave lithotripsy in a 35-year-old man. The fragments passed through the outside via both the drain and stool. A few fragments which remained in the T-drain and the distal bile duct were easily flushed out later.

Adult↗
PubMed1984

[Clinical value of thrombocyte aggregation inhibitors during massive-dose estrogen therapy].

Due to an advanced prostatic carcinoma 166 patients were given a massive dose of oestrogen over a period of 10 days (6 g Honvan i.v.). A retrospective comparison of a control group of 94 patients without prophylaxis against thrombosis and a control group of 36 patients having received Heparin-Dihydergot did not show a significant difference of cardiovascular complications. Therefore, further 36 patients received a thrombocyte aggregation inhibitor (Godamed) as prophylaxis against embolic thrombosis. At the same time lung perfusion scintigraphy (99m Tc-Microspheres) was made directly before and after oestrogen therapy. Clinically and lung scintigraphically there was no different thromboembolic incidence compared to the patients given a Heparin-Dihydergot prophylaxis.

Aged↗
PubMed1982

[Honvan-high-dose therapy of prostatic carcinoma with metastases: early complications and value of prophylaxis against thrombosis].

Since 1972 in the Urology Department at Darmstadt Hospital the Honvan-high-dose-therapy of 130 patients with metastatic prostatic carcinoma has been carried out under standardizing condition. The analysis shows that there is no significant difference between the patients with prophylaxis against thrombosis (Macrodex and Dihydergot-Heparin) and without prophylaxis. The patients with anti-thrombotic prophylaxis demonstrated significantly higher incidence of reversible elevation of transaminases. The effect of Heparin is probably responsible for this.

Aged↗
PubMed1982

Early arterial lesions in infancy and childhood and ways of prevention.

Arterial lesions appear in the human vascular system early in life. In some predisposed arterial segments calcifications of the internal elastic sheets have regularly been demonstrated macroscopically in infancy and early childhood. Atherosclerotic lesions also begin in childhood, and the seeds of their later clinical manifestations are probably sown in infancy. Hyperlipemia, hypertension, and cigarette smoking represent the major risk factors of atherosclerosis and its premature development. Accordingly, the main task of pediatricians is early identification of the risk groups and their appropriate treatment, particularly of children with hyperlipoproteinemia type II and those with family history indicating a premature atherosclerotic event, hypertension, and diabetes mellitus. In most populations, however, elevated serum cholesterol levels are probably not caused by genetically determined metabolic disorders but mainly promoted by environmental factors, such as nutrition. Therefore, establishment of beneficial nutritional habits early in life may prevent the development or at least limit the extent of fatty streaks and their further transformation into fibrous plaques or more advanced atherosclerotic lesions. The education of the community, especially of parents, to the hazards of the cardiovascular risk factors must become an essential part of preventive programs directed to sound cardiovascular health. The wide individual variation of the extent of early lesions, e.g., of fatty streaking in childhood even in most homogeneous population subgroups, points to the existence of still undiscovered risk factors. Cooperative efforts between pediatric pathologists and pediatricians appear, therefore, a necessity for further progress in the evaluation of these factors and for establishing successful preventive programs.

Adult↗
PubMed1981

Report on a very young dizygotic human twin pregnancy.

Two ova implanted in one uterus were found at the autopsy of a 28-year-old woman. The ovulation age of both implantations has been estimated to be 10-12 days. The presence of two equally large corpora lutea, one in each ovary, indicates that the implanted ova originated from different ovaries. Thus, an "ovulatio biovarialis" seems to be the basis for the dizygotic twinning in this case. The case is believed to be the only documented example of a very early dizygotic, fraternal pregnancy in humans.

Adult↗
PubMed1980

Studies on human aortic bifurcation. Part 1. Histo-architecture of the bifurcation.

The re-examination of the histo-architecture of the human aortic bifurcation was mainly focused in this study on the structure of its divider and the medial walls of its daughter vessels, both being presumably exposed to a higher mechanical strain as compared with other parts of the bifurcation. The microscopic structure of the divider is characterized by an arch-like course of its musculo-elastic structural components which follow the crescent shape of the dividers rim. Accordingly, in the central part of the divider the musculo-elastic bundles show a nearly horizontal course. They arise in both extensions and become more and more longitudinally disposed. This arch-like arrangement of the musculo-elastic core of the divider has been interpreted as a structural accomodation to the frontal impact of the axial pulsative blood stream upon the dividers rim. The tension which results from this impact is probably transferred by the dividers extensions into the aortic wall above the divider and in this way may be evenly distributed over the aortic tube. The medial wall of the bifurcation is characterized, in infants, by cushion-like thickenings of the arterial wall. These thickenings probably represent specialized structures which cope with a higher shear stress of longitudinal tension. In the asymmetrical aortic bifurcation of infants who had a single umbilical artery the cushion was present at the medial wall of the larger part of the bifurcation only, i.e. at the side of the single umbilical artery. This underlines the significance of the higher functional load for the development of this additional structure at the medial wall. The predominantly longitudinal arrangement of the musculo-elastic medial elements along the medial wall of the bifurcation in adolescents and young adults points to a considerable longitudinal tension to which this part of the arterial tube may be exposed.

Accidents, Traffic↗
PubMed1980

Studies on the human aortic bifurcation. Part 2. Predilection sites of early lipid deposits in relation to preformed arterial structures.

The site of fatty streaking in the human aortic bifurcation has been re-examined in 22 specimens from persons who died suddenly between the ages of 14 and 35 years. In contrast to the earlier data of others which pointed to the predominant involvement of either lateral or medical wall, fatty streaking has been found to be localized initially along the posterior wall of the bifurcation and its daughter vessels, i.e. common iliac arteries. This localization appears to be related to a prominent development of the intima along the posterior wall of the bifurcation. The appearance of fatty streaking along this wall may also be favored by the slightly curved pattern of the human aortic bifurcation. The morphometric analysis demonstrates a greater involvement of right common iliac artery by fatty streaking as compared with the left artery. The elastic sheet covering the divider of the bifurcation was identified microscopically as another common site of an early lipid deposition in the aortic bifurcation. The early lipid infiltration of the elastic sheets is partly responsible for the diffuse reddish coloration ("blush") appearing with gross fat staining at the lateral aspects of the divider and in other affected areas.

Adolescent↗