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Biomedical subjects

F Oberpenning

Publications and source records attributed to F Oberpenning.

26 records · Page 2Linked to original sources
PubMed1995

Surgical management of renal cell cancer with extension into the vena cava: usefulness of intra-operative sonography.

Intracaval tumour extension represents a significant surgical problem in patients with renal cell carcinoma. Although pre-operative imaging techniques provide sufficient visualization for the planning of the majority of operative procedures, intra-operative ultrasound is nonetheless beneficial in some cases. In 3 patients, the procedure has given an accurate evaluation of the extent of the tumour thrombus. It has allowed safe placement of instruments which had lessened the risk of thrombus dislodgement. Intra-operative sonography is simple to perform and can be considered a valuable new adjunct in the evaluation and management of renal cell carcinoma with intracaval tumour extension. New technological advances may eventually improve the quality of intra-operative imaging.

Carcinoma, Renal Cell↗
PubMed1995

[Different determination methods make interpretation of prostate-specific antigen more difficult].

The availability of numerous different assays for the determination of prostate-specific antigen (PSA) hs created substantial problems in the interpretation of PSA concentrations. Presently more than 40 assays are commercially promoted within the German market. The majority of the recently released assays claim the commonly used reference range (< 4 ng/ml) although this has no always been verified. Some companies entirely avoid the specification of reference ranges, others derive the data from very small cohorts. Reference ranges established with sera of young males or even with an unknown proportion of female sera are not valid in assessing the specificity of PSA assays to detect prostate cancer among male individuals between 50 and 80 years of age. Some companies recommend not to apply their assay for diagnostic purposes limit its use to the follow-up of patients previously diagnosed but to as having prostate cancer. This warning usually remains just as unknown to the urologist as the name of the assay used. Since PSA concentrations may vary in identical samples by a factor of 2, depending on the assay used, the clinician interpreting the results needs to be aware of the method applied and must have detailed information about the assay-specific reference range. Without this information, PSA loses its valuable diagnostic and prognostic features. Apart from avoidable worries on the patient's part, evidence of prostate cancer may be missed or unnecessary biopsies may be performed.

Aged↗
PubMed1994

The Alcock syndrome: temporary penile insensitivity due to compression of the pudendal nerve within the Alcock canal.

Penile insensitivity is a symptom commonly observed after traumatic or iatrogenic nerve lesions, or in association with neurological or vascular diseases. In contrast, we report 2 cases of intermittent genital hypesthesia that occurred in cyclists after long-term bicycle riding. Anatomical studies show that this condition was probably caused by an irritation of the pudendal nerve during its course through the Alcock canal as reported in the literature. No pathological findings were demonstrated on extensive physical examinations, medical history and all medical imagings (sonography of abdomen, prostate and testes, and magnetic resonance imaging of the pelvis and lumbar spine) as well as radiodiagnostics and Doppler sonography, nor was there evidence of other neurological disturbances. The symptoms in the 2 patients spontaneously resolved after 4 and 7 weeks, respectively, without specific medical therapy.

Bicycling↗
PubMed1994

Basal cells of the human epididymis--antigenic and ultrastructural similarities to tissue-fixed macrophages.

Very little is known about the basal cells in the epididymal epithelium. Their function is unclear, although they are present in all mammalian epididymides studied. The corpus epididymides from five patients undergoing castration because of prostatic carcinoma were fixed and processed for electron microscopy. Basal cells were characterized by a slightly heterochromatic nucleus with prominent nucleolus, pale round mitochondria, dispersed endoplasmic reticulum, and sparse Golgi apparatus; they were often rich in lipofuscin inclusions, possibly originating from principal cells. Some peritubular macrophages in close proximity to the epithelium were structurally similar to basal cells. Immunohistochemical staining revealed in the epididymides of another ten patients that the basal cells were recognized by the monoclonal antibody (mAb) 25F9 against mature, tissue-fixed macrophages but not by mAbs 27E10 or RM3/1, which were against activated macrophages usually found in acute or late inflammation, respectively. On the basis of the present findings, as a working hypothesis a scavenging role of the basal cells in a local immune defense mechanism is proposed, in which antigenic products (possibly of sperm degradation), taken up by the principal cells, would be phagocytosed by the basal cells. It could be inferred that when the basal cells are overloaded, they would leave the epithelium to be replenished by tissue-fixed macrophages.

Aged↗
PubMed1993

Changes in movement characteristics of human spermatozoa along the length of the epididymis.

It has been established in laboratory mammals that sperm motility and fertilizing capacity develop during epididymal transit, but sperm maturation along the human epididymis is less well characterized. Spermatozoa were prepared from 5 regions of 8 epididymides from 8 prostatic carcinoma patients undergoing castration and from 8 epididymal spermatocoeles located adjacent to the head of the epididymides and the testes of 5 patients. Sperm movement was characterized by computer-aided sperm analysis (CASA), and percentage motility was estimated by conventional methods. The efferent ducts and spermatocoeles contained the same percentage of motile spermatozoa with similar kinematics. Percentage motility increased from 22.9 +/- 4.8 (mean +/- SEM) in the efferent ducts to a maximum of 68.3 +/- 7.9 in either the mid- or distal corpus epididymidis and declined in the cauda region. Straight line velocity increased from 20.3 +/- 3.7 microns/sec to reach a plateau value of 44.0 +/- 5.3 microns/sec in the mid-corpus epididymidis; this was more marked than the increase in curvilinear velocity, although the trend was the same. Similar trends in linearity and straightness of the swim paths were not accompanied by any significant changes in the amplitude of lateral head displacement. This objective quantification of sperm movement documents the maturation of sperm motility in the human epididymis, confirming that this maturation pattern is similar to that in other mammals.

Epididymis↗
PubMedDate not supplied

The impact of intraoperative manipulation of the prostate on total and free prostate-specific antigen.

OBJECTIVES: It is well documented that mechanical manipulation of the prostate can elevate total PSA (t-PSA) levels in serum. However, less is known about its effects on free PSA (f-PSA) and the free-to-total PSA ratio (f/t-PSA). We therefore examined the impact of prostate manipulation on t-PSA and f-PSA during surgical procedures involving the prostate. METHODS: Intraoperative blood samples for t-PSA and f-PSA measurement (Hybritech) were collected every 15 min during 14 radical retropubic prostatectomies (RRP) and 10 radical cystoprostatectomies (RCP). RESULTS: Prostatic manipulation induced significant elevations in t-PSA and f-PSA during RRP and RCP. Postmanipulatory peaks were markedly higher for f-PSA than for t-PSA. The mean maximum f-PSA levels showed a 4.3- (RRP) and 7.9-fold (RCP) increase, followed by a rapid decline after prostate removal. t-PSA increased 1.2- (RRP) and 1.3-fold (RCP), and declined more slowly. Postmanipulatory f/t-PSA ratios also increased significantly, reaching mean elevations of +0.29 and +0.28 over preoperative ratios during RRP and RCP, respectively. CONCLUSIONS: Prostate manipulation can induce transient increases in t-PSA, f-PSA and f/t-PSA in benign and malignant prostates. The extent of these alterations and their course over time must be taken into account when postmanipulatory changes in PSA forms are investigated. Timing of postmanipulatory venipunctures and the molar response ratio of t-PSA assays used (equimolar versus nonequimolar) seem to have substantial impact on the results of such studies.

Adult↗
PubMedDate not supplied

Radical prostatectomy: survival outcome and correlation to prostate-specific antigen levels.

BACKGROUND: This paper reviews a 10-year experience with radical retropubic prostatectomy (RP) focussing on survival outcome related to pre- and postoperative levels of prostate-specific antigen (PSA). PATIENTS AND METHODS: 739 patients who underwent RP between 1987 and 1998 were prospectively investigated. Kaplan-Meier analyses were performed and correlated to pre- and postoperative PSA concentrations. RESULTS: In a follow up period of 11 years duration, (mean 3 yrs.) 57 of 739 patients died (20 from prostate disease progression, 37 from other causes). Correlation between low pre-operative PSA and pathological organ-confinement was significant (p < 0.001). Of 175 patients with PSA progression, 53 (30%) had never reached undetectable levels of PSA. 57% of PSA relapses were detected during the first year, and 3% later than 5 years post-operatively. Kaplan-Meier analysis yielded an average 3 years advantage in estimated prostate-cancer-specific survival when pre-operative PSA levels were below 50 ng/ml. Overall, prostate-cancer-specific and PSA-free 5-year survival-rates were 88%, 96% and 67% respectively. CONCLUSIONS: Survival-rates after RP are high even in conjunction with unfavourable PSA outcome. Merely one third of deaths resulted from prostate cancer, since men at risk frequently suffer from concomitant diseases that affect survival.

Aged↗