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Biomedical subjects

K Maar

Publications and source records attributed to K Maar.

At least 19 recordsLinked to original sources
PubMed1988

Ultrasound guided percutaneous biopsy or operative biopsy in patients with renal impairment?

Sixty-four percutaneous renal biopsies under ultrasound guidance done in 60 patients with renal impairment are compared with 33 open, operative biopsies. In 62 percutaneous biopsies (96.8%), more than 3 glomeruli could be obtained. Eight biopsies (12.5%) presented with minor complications afterwards. All of them were spontaneously reversible. In the operative biopsy group, there were complications in 6 patients (18.2%). In 2 cases, operative revision was necessary. In conclusion, percutaneous ultrasound guided biopsy in experienced hands offers several advantages in patients with renal impairment. It must be kept in mind that from a minority of patients only an operative biopsy can be taken due to certain risks.

Adult↗
PubMed1985

Steroid receptor status of human testicular tumors.

Biopsies of 9 testicular tumors were examined for the presence of cytoplasmic receptor proteins for estrogens, progestins, androgens, and glucocorticoids. Using an arbitrary threshold value of 10 fmol/mg cytosol protein for a postive assay, only 1 of 9 tumors was estrogen-receptor positive. However, no receptor-specific 8S binding could be detected by low salt sucrose gradient centrifugation. 1 tumor was progesterone-receptor positive. No androgen receptors could be demonstrated. In contrast, 8 of 9 neoplasms contained significant quantities of glucocorticoid receptors exclusively sedimenting at 8S. Our findings suggest that androgens, estrogens, and progestins are unlikely to play a major role in the natural history of testicular tumors. The presence of glucocorticoid receptors might offer a chance for endocrine manipulation of the development and growth of these neoplasms by glucocorticoids.

Adolescent↗
PubMed1983

[Unusual benign and malignant ureteral stenosis. Causes, therapy and clinical course].

In 652 patients with ureteral stenoses treated in the last 23 years we found 12 (1.8%) patients with rare benign and 5 (0.7%) patients with rare malignant diseases resulting in ureteral stenoses. Causes, clinical symptoms, diagnostic procedures and pathohistological findings are analysed and discussed with emphasis on the pathohistological diagnosis. Operative procedures are demonstrated and long term follow-up studies presented.

Adult↗
PubMed1982

[Experience with the internal splinting method (endoprosthesis) (author's transl)].

We have used internal splints for 20 years; the endoprosthesis creates an internal urinary diversion of dilatated kidneys due to incurable gynecological, prostatic and bladder cancer. Also in pyeloplasties, difficult stone operations and retroperitoneal fibrosis the pyelovesical splinting method is useful. Scanning electron microscopic research shows that incrustations are rare and even not existing if siliconised polyvinylchlorid (PVC) splints are used. The so called "pig-tail"-splint (double-JTM-ureteral stent) is of pure silicone material and therefore well fit for therapy even over a longer period.

Adult↗
PubMed1981

[Results after varicocelectomy Palomo's operation (author's transl)].

123 patients with fertility problems were examined after 6 months, 1 year and more than 1 year, postoperatively following Palomo's operation. Preoperative semen analysis was done in all cases. The most important aspects of this study are: 1. Excellent quality of semen characteristics after the first 3 postoperative months. 2. Reduced semen quality during the following time. 3. Most frequent complication was a aseptic epididymitis which could be caused hemodynamically. 4. Necrosis of the testicle was never observed.

Adult↗
PubMed1980

The endocrine background of human renal cell carcinoma. V. Binding of the highly potent androgen methyltrienolone (R 1881) by tumour cytosol.

The binding of methyltrienolone (R 1881, 17 beta-hydroxy-17 alpha-methyl-estra-4,9,11-trien-3-one), a highly active synthetic androgen, by cytosol preparations from human renal cell carcinoma was investigated. High-affinity, low-capacity binding components for R 1881 were detected in 3 out of 8 tumours analysed. The apparent dissociation constant of the R 1881-binder complexes was found to be in the range of 1.1-2.3 x 10(-9) mol/l. The number of binding sites in the positive tumours varied from 2.1 to 9.7 fmol/mg cytosol protein. Studies of binding specificity indicated a requirement for androgens. It is concluded that these binding components may be hormone receptors. If in consecutive studies this hypothesis holds true, progestins, most widely used in hormonal therapy of metastatic renal cancer, may possibly act on the tumour tissue by inhibiting the secretion of gonadotropins, thus lowering the blood levels of eventually growth-promoting.

Adenocarcinoma↗
PubMed1980

[Combined epidural anaesthesia as an alternative to inhalation anaesthesia as exemplified in radical lymphadenectomy in testicular malignomas (author's transl)].

In a retrospective study of retroperitoneal lymph-adenectomy it was investigated whether the choice of anaesthesia and the difference in management of postoperative pain alleviation does influence the postoperative course. In comparing group I (n = 43), patients anaesthesized with volatile anaesthetics (enflurance, halothane) while postoperative pain relief was obtained by meperidine and pentazocine and group II (n = 28), anaesthesized with a high epidural block combined with light narcosis with oxygen, nitrous oxygen and diazepam, while postoperative pain relief was obtained by a continuous epidural block we found: In comparison to group I the stay in group II was shorter. There was one patient in group II with intestinal obstruction, but in group I were seven patients with clinical signs of intestinal obstruction. In group I the evaluation of the bowel took place after 36 hours, in group II after 20 hours. One patient in group I died after three days because of pneumonia combined with intestinal obstruction. The consumption of meperidine and pentazocine in comparison group II to group I were diminished to round about 85%. We think that there is a direct relation between anaesthesia, postoperative pain alleviation and the postoperative course. High epidural anaesthesia in combination with light anaesthesia and postoperative epidural analgesia seems to be better than inhalational anaesthesia for the patients we explored in our retrospective study.

Anesthesia, Epidural↗
PubMed1979

The endocrine background of human renal cell carcinoma. I. Binding of the highly potent progestin R 5020 by tumour cytosol.

Based on the potential sensitivity of the growth of human renal cell carcinoma, tumour tissue from 88 patients was analysed for progestin receptors. With the dextran-coated charcoal assay, cytoplasmic components which bound the potent progestin R 5020 specifically and with high affinity could be detected in 42% of the carcinomas. The apparent dissociation constant of the R-5020-binder complex amounted to 3.1 +/- 1.2 X 10(-8) mol/l. Sedimentation in sucrose gradients revealed the bulk of these components to be in the 4-S region. The ligand specificity for binding to these sites indicated a requirement for progestins. Despite the enormous case material investigated, we were unable to confirm the presence of the high receptor concentrations reported in the literature.

Adenocarcinoma↗
PubMed1979

The endocrine background of human renal cell carcinoma. II. Attempt to induce the R-5020-binding components by oestrogens.

In an attempt to elevate the concentration of progestin-binding components in human renal cell carcinoma, 24 patients were treated prior to tumour nephrectomy with various doses of oestrogens, potent inducers of progestin receptor synthesis. Low-dose oestrogen treatment was found to be insufficient to significantly induce progestin-binder synthesis in the tumour tissue. In the carcinoma of patients receiving high-dose oestrogen treatment, the average concentration of R-5020-binding sites did not differ from that of the low-dose group. However, 2 out of these patients (12.5%) exhibited R-5020-binder concentrations in the tumour tissue which exceeded the highest quantities of progestin-binding components found in 88 untreated controls previously analysed in our laboratory.

Adenocarcinoma↗
PubMed1979

The endocrine background of human renal cell carcinoma. III. Role of inhibitors of R 5020 binding in tumour cytosol.

Cytosol preparations obtained from 9 different human renal cell carcinomas were investigated for the eventual presence of progestin-binding inhibitors which might offer an explanation for the previous failure to demonstrate high receptor levels in the tumour tissue. The inhibitory potency of these preparations was estimated by measuring the decrease of R 5020 binding to uterine progestin receptors in the presence of tumour cytosol. Interestingly, cytosol from human renal cell carcinoma was found to contain progestin-binding inhibitors. The average inhibition of R-5020-receptor interaction amounted to 46%. In only 1 out of 9 cases, binding was completely suppressed. In order to circumvent the inhibitory reaction potentially occurring in cell-free systems, R-5020-binding studies additionally were performed in cell suspension. Out of 7 carcinomas studied using this assay system, 5 did not contain any specific progestin-binding entities. In 1 tumour, receptor-atypical non-saturable binding was observed. Only in isolated cells prepared from 1 other carcinoma, could slight indications for the presence of low concentrations of progestin receptors be detected.

Adenocarcinoma↗
PubMed1979

The endocrine background of human renal cell carcinoma. IV. Glucocorticoid receptors as possible mediators of progestogen action.

In order to investigate whether progestins may trigger tumour regression by a mechanism involving the glucocorticoid receptor, human renal cell carcinomas obtained from 15 patients were analysed for cytoplasmic glucocorticoid-binding components, using [3H] dexamethasone. The existence of glucocorticoid binders could be demonstrated in 10 out of 15 tumours studied. The average binding capacity was calculated and found to be 7.1 fmol/mg of cytosol protein. The apparent dissociation specificity experiments clearly cell-free system amounted to 1.9 X 10(-8) mol/l. The ligand specificity experiments clearly indicated that binding to these receptors is not restricted to glucocorticoids alone. Progesterone and aldosterone turned out to be moderate competitors for dexamethasone binding. Medroxyprogesterone acetate, the compound widely used in hormone therapy of advanced renal cancer in man, was demonstrated to be one of the strongest inhibitors of [3H] dexamethasone. It is concluded that binding of medroxyprogesterone acetate to glucocorticoid receptors might represent the primary mechanism of action of the compound in causing tumour regression.

Adenocarcinoma↗
PubMed1979

[Viable cells from human renal cell carcinoma: isolation procedure and analysis of hormone sensitivity (author's transl)].

An enzymatic procedure for the isolation of metabolically active tumour cells from human renal cell carcinoma is described. The cells were suspended by a multistep incubation procedure of the tissue in the presence of collagenase (10 mg enzyme/g tumour wet weight) dissolved in a calcium-free buffer solution. About 90% of the isolated tumour cells were viable, as judged by routine trypan blue staining. Electron microscopic examination revealed tumour cells in various stages of dedifferentiation. The cells had retained their capability of protein synthesis. In short term experiments the effects of 17 beta-oestradiol and progesterone on the incorporation of [U - C] L-leucine into cellular proteins was studied; Progesterone was found to exhibit a slight tumour antianabolic or catabolic action. A 17 beta-oestradiol-dependent modulation of the rates of protein synthesis was not observed.

Adenocarcinoma↗
PubMed1977

Distribution of oestradiol receptor molecules in human kidney.

Experiments were performed to determine the distribution of oestrogen receptors in normal human kidney. Cytosols prepared from renal medulla and cortex were separately analyzed for oestrogen receptor molecules aga gel electrophoresis. Oestrogen receptors could be demonstrated in both compartments of the organ. However, the experiments reveal that the medulla is the main locus of oestrogen receptor in human kidney.

Aged↗
PubMed1977

[Indication and clinical value of vesiculodeferentography concerning urologic-andrologic diseases (author's transl)].

There are 29 cases of vesiculodeferentography (VDG) (1962-1975) presented. The very indication of VDG was the evaluation of azoospermia due to occlusion of the vas deferens, in addition to other urologic diseases. Especially from the andrologic point of view the various forms of occlusion-azoospermia are classified and analyzed. It is pointed out, that the rete testis region is not to be elucidated by VDG.

Blood↗