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Biomedical subjects

G H Jacobi

Publications and source records attributed to G H Jacobi.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Accuracy of computer tomography in urinary bladder cancer. Study of 74 patients following radical cystectomy].

The accuracy of computed tomography in staging bladder carcinoma has been investigated in 74 patients who underwent cystectomy (n = 70) and pelvic lymphadenectomy (n = 74). The results of the initial CT findings (prospective analysis) and the results of reviewing all CT scans retrospectively by 3 investigators have been compared. Retrospectively, T-staging was correct in 64%, overstaging was seen in 26% and understaging in 10%. N-staging was correct in 99% (n = 73/74) and obstruction of the upper urinary tract with dilatation of the ureter could be diagnosed in every case. The differences between retrospective and prospective analysis are discussed. Staging errors are seen in patients with tumor infiltration of the prostate or the uterus, with microscopic invasion of the perivesical fat, after irradiation of the pelvis or previous surgery. Metastatic involvement of lymph nodes below 1.5 cm diameter cannot be recognized.

Adolescent↗
PubMed1983

Adriamycin permeability of the rat bladder under different conditions.

Fifty female Sprague-Dawley rats were treated with 1.4 or 2.4 mg. adriamycin intravesically. Radioimmunological measurement of serum concentrations were performed up to 3 hours post-instillation in normal bladder mucosa, cystitis, and after electrocoagulation, under different filling conditions, as well as with the use of a detergent (Tween 80). The serum concentrations achieved were markedly higher after electrocoagulation or cystitis; altogether they reached only 1/6,000 of the instilled concentration. These studies on the rat bladder suggest that perioperative instillation of adriamycin to prevent recurrence is not contraindicated shortly before or after transurethral resection (TUR) of superficial bladder tumors.

Absorption↗
PubMed1983

Influence of cis-platinum on healing of enterostomies in the rat.

The influence of cis-platinum on the wound healing of bowel anastomoses was studied in 104 male Sprague-Dawley rats. After a single preoperative doses of 5 mg/kg body weight, the wound-breaking strength (WBS) was tested with a material tester on the 4th, 7th, 14th and 28th day postoperatively. The WBS was significantly lower in treated animals as compared to the untreated controls. The reasons for this are discussed in comparison with other cytotoxic agents. Before cis-platinum can be used as adjuvant chemotherapy to cystectomy, which is frequently combined with an ileum or colon conduit procedure, further investigations on the operative side effects of cis-platinum on bowel anastomoses are necessary.

Animals↗
PubMed1982

The effects of chlorotrianisene (Tace) of kinetics of 3H-testosterone metabolism in patients with carcinoma of the prostate.

Alterations in the metabolism of testosterone and plasma levels of testosterone, luteinising hormone (LH), follicle stimulating hormone (FSH), prolactin and oestradiol were studied in 6 patients with newly diagnosed prostatic carcinoma before and during treatment with chlorotrianisene at a daily dosage of 48 mg for 14 days. Parameters of plasma kinetics were determined according to the single injection technique and the 2-compartment model, and the plasma hormones by radioimmunoassay. Chlorotrianisene altered neither plasma levels of testosterone, gonadotrophins, prolactin and oestradiol, nor metabolic clearance rate, production rate and other kinetic parameters of testosterone. Thus the beneficial effects which have been reported previously cannot be explained by suppression of peripheral testosterone metabolism.

Aged↗
PubMed1982

Gonadotropin-releasing hormone analogues for prostate cancer: untoward side effects of high-dose regimens acquire a therapeutical dimension.

Gonadotropin-releasing hormone (Gn-RH), a hypothalamic decapeptide, mediates the synthesis and release of pituitary luteinizing hormone (LH). Synthetic Gn-RH analogues with prolonged duration of action are therapeutically administered with 'pro-fertility' intention to overcome endogenous Gn-RH deficiency, i.e. hypogonadotropic hypogonadism and related disorders. When Gn-RH analogues are chronically administered in high supraphysiological dosages, however, a paradoxical effect of pituitary overstimulation becomes evident: gonadotropin release is reduced, Leydig cell responsiveness is impaired, and testosterone secretion is blocked to castrate levels. Metabolic mechanisms involved include desensitization of the pituitary to Gn-RH, down-regulation of Gn-RH receptors, the depletion of the releasable LH pool, the breakdown of physiological feedback mechanisms, as well as direct interactions of the Gn-RH analogue with the Leydig cell. It is tempting to assume that, on the basis of this untoward side effect, high dose Gn-RH analogues will acquire a therapeutical dimension in the palliative treatment of prostate cancer. The therapeutical effect of castrate levels of testosterone is achieved without orchiectomy, cardiovascular side effects of estrogen are avoided, and the drug is conveniently applicable via the pernasal route. From the data available today Gn-RH analogues in overstimulatory dosage can be expected to be safe and effective in the palliative treatment of prostate cancer and would thus prove a true alternative to conventional contrasexual measures.

Adolescent↗
PubMed1982

Experimental investigations on the absorption of intravesically instilled mitomycin C in the urinary bladder of the rat.

After ligation of ureters and urethra, male Sprague-Dawley rats were treated over 3 h with either 2 mg mitomycin C (MMC) intravesically (group I), or in conjunction with pre-instillation bladder electrocoagulation (group II) or iatrogenic Escherichia coli/xylene-induced severe cystitis (group III). Vesical absorption of MMC was investigated by measuring serum MMC up to 180 min postinstillation on the basis of a thin agar plate method. There was no statistically significant different with regard to the total amount of MMC absorbed between groups I and II. However, when groups I and III or II and III were compared, a significant differing transvesical absorption was calculated, being higher for the electrocoagulation than for the cystitis group. The possible clinical implication of this finding is discussed in connection with the most recent literature.

Absorption↗
PubMed1982

Endocrine studies with a gonadotropin-releasing hormone analogue to achieve withdrawal of testosterone in prostate carcinoma patients.

This investigation on 12 well-defined patients with untreated, advanced prostatic adenocarcinoma establishes the gonadotropin-releasing hormone analogue [D-Ser(But)6](1-9)-nonapeptide-ethylamide (Hoe 766) as an effective, safe and non-toxic form of medical castration. Hoe 766 was given either as subcutaneous injections of 2 x 200 micrograms/day over 14 days and pernasal application (3 x 400 micrograms/day) thereafter, or as subcutaneous injections of 3 x 1,000 micrograms/day over 6 days and pernasal application thereafter in the dosage mentioned above. Both dose regimens were equally effective: pituitary overstimulation between days 3 and 6 with a rise of serum HL and testosterone; pituitary and testicular desensitization with LH and testosterone decline between days 6 and 14; medical castration with average serum testosterone levels maintained around 0.5 ng/ml for up to 12 weeks. Except for transient hot flashes in 4 patients, no clinical or laboratory side effects were observed. It is concluded from this study that the gonadotropin-releasing hormone analogue. Hoe 766, is a valuable alternative to conventional contrasexual measures for prostate cancer palliation. To improve the patient's compliance, however, the smallest single pernasal dosage effective for maintenance of down-regulation and steroidogenic arrest has still to be determined.

Adenocarcinoma↗
PubMed1981

In vivo studies on the antiandrogenic effects of cimetidine versus cyproterone acetate in rats.

To investigate the antiandrogenic action of cimetidine in vivo, prostatic androgen uptake and metabolism, spermatogenesis, morphology of the prostate and testes, and plasma hormone levels were studied using Sprague-Dawley rats, and the results were compared with the effects of cyproterone acetate or castration. Cimetidine and cyproterone acetate caused significant reduction in the weights of the ventral prostate and testes. The changes of ventral prostate were accompanied by a dose-related epithelial atrophy. No adverse effect on spermatogenesis was observed after treatment with cimetidine at daily doses of 50 mg/kg or cyproterone acetate of 10 mg/kg. Although cimetidine treatment induced a significant decrease in plasma testosterone levels, the uptake of testosterone-3H and its conversion to DHT of the ventral prostate were not inhibited by cimetidine.

Androgen Antagonists↗
PubMed1981

Ferritin - another tumor marker for testicular malignancies.

On the basis of results obtained with other malignancies, the usefulness of serum ferritin as a tumor marker in the diagnosis of testicular tumors was studied. In 68 patients with malignant testicular tumors and 22 patients with benign testicular processes, serial determinations of beta-human chorionic gonadotropin (beta-HCG), alpha-fetoprotein (AFP) and serum ferritin were performed. The serum ferritin values showed no relationship to tumor stage, and no difference in nonseminomatous and seminomatous tumors. In particular, no diagnostic improvement was achieved in those cases in which the conventional markers AFP and beta-HCG were unsuccessful (falsely negative results). Furthermore, serum ferritin values were influenced by hepatic factors and anemia, so that serum ferritin - on the basis of the present material-could not be considered a useful tumor marker in testicular malignancies. Further studies on the determination of carcinofetal isoferritin and other new tumor markers are warranted.

Adolescent↗
PubMed1981

[Diffusion of co-tetroxazin into prostatic tissue (author's transl)].

For 2,4-diamino-5-[3,5-dimethoxy-4-(2-methoxyethoxy)]-benzylipyrimidine (tetroxoprim, TXP) and 4-amino-N-(2-pyrimidinyl)benzenesulfonamide (sulfadiazine, SDZ) tissue levels in prostate adenoma patients were 10.75 +/- 5.83 micrograms/g an 8.52 +/- 3.88 micrograms/g, respectively. In accordance with the determined plasma levels of 1.54 +/- 0.53 micrograms/ml TXP and 17.39 +/- 6.11 micrograms/ml SDZ, the prostate/plasma coefficients were found to be 8.26 (TXP) and 0.48 (SDZ).

Diffusion↗
PubMed1980

Silicone-silver penile prosthesis: description, operative approach and results.

A silicone penile prosthesis in which silver wires are embedded to allow for voluntary bending of the penis for urination and resting position and for straightening for intercourse is described. The implantation is done via a hemicircular incision on the dorsum of the penis in the sulcus coronarius. Buck's fascia is identified and opened, and the corpora are dilated up to 30F. After the exact length is determined with a special sizer the prosthesis is slipped into each corpus cavernosum. The advantage of this approach is the optimal insertion of the prosthesis distal to the sulcus coronarius, thereby preventing kinking of the glans during intercourse. Our experiences with the implantation in 17 patients followed for 1 to 14 months showed successful results in 15.

Humans↗
PubMed1980

Treatment of advanced prostatic cancer with parenteral cyproterone acetate: a phase III randomised trial.

Forty-two patients with previously untreated T3/4 N1-4 MO/1 prostatic adenocarcinoma were treated with either cyproterone acetate (n = 21; 300 mg intramuscularly per week) or oestradiol undecylate (n = 21; 100 mg intramuscularly per month) after extensive staging which included open skeletal biopsy and pelvic lymphadenectomy in some cases. Subjective and objective parameters as well as signs of drug toxicity were recorded regularly. Evaluation after 6 months showed cyproterone acetate to be more effective in the following respects: (1) the significantly different castration effect as judged by plasma testosterone, (2) the objective voiding pattern and tumour response, with regression of palpable and histologically evaluable local tumour in 16 of 21 patients, and (3) side effects and untoward reactions. Thus cyproterone acetate is suggested as a valuable alternative in the treatment of advanced prostatic cancer.

Adenocarcinoma↗