Nuclear magnetic resonance studies of linear,cyclic and polymeric peptides containing His,Ser and Asp residues spaced by ß alanylglycine

¹H and ¹³C nuclear magnetic resonance studies have been carried out on the linear, cyclic and polymeric peptides having a sequence of -Asp-ßAla-Gly-Ser-ßAla-Gly-His-ßAla-Gly-. From the ¹ H spectra measured at 400 MHz, the rotamer populations about side chain Cα-Cß bond for Asp, Ser and His residues were estimated at pD 5 and 8. For Asp and Ser residues, the rotamers T (trans), G and G' (gauche) had an equivalent population at both pDs, while for His residue the rotamer G' had a higher probability than the others. ¹³C chemical shift of His and Asp residues measured at a frequency 15 MHz showed a considerable change in the pD ranges 3 ? 5 and 5 ? 8, respectively, owing to the ionizable side chains. The pK value for His residue, i.e. the midpoint of the chemical shift change, corresponded fairly well to that obtained from ester hydrolytic activity measurements, supporting the previous suggestion that the ester hydrolytic reaction is mainly controlled with the imidazole group of His residue. ¹³C spin-lattice relaxation time T₁ was measured in order to investigate the molecular motion. It was found that the backbone was composed of relatively movable parts, -ßAla-Gly-, and less movable parts, Asp- Ser and His. Thisphenomenon was especially remarkable at the higher pD. The internal motion in the side chain was also investigated using the relaxation theory for the molecules undergoing the internal rotation. These results of relaxation measurements were compared with the results of conformational studies by circular dichroism measurements. The polymeric peptide composed only of -His-ßAla-Gly- sequence was also measured as a related peptide.     

Clinical features of testicular tumors in children

AIM: Testicular tumors are not common pediatric solid tumors, especially in Asian children. There have been few reviews of cases in Japan to date. We present the clinical features of 14 pediatric testicular tumor patients. METHODS: Clinical features of 14 testicular tumor patients, such as chief complaints, age at diagnosis, pathology, stages, treatments and prognosis, were examined from medical records. Two patients had their semen tested at adolescence. RESULTS: Of the 14 prepubescent patients, 12 (85.7%) patients were diagnosed before 3 years of age. Ten cases (71.4%) were diagnosed as yolk sac tumors, three (21.4%) as mature teratomas and one case as an epidermoid cyst. Nine cases (90.0%) among the 10 cases of yolk sac tumor were diagnosed as stage I and one case was stage IV. One stage I yolk sac tumor patient developed lung metastasis later. Eventually, two yolk sac tumor patients died, despite chemotherapy. While all the cases with a diagnosis before 2 years of age survived, 67% (2/3) of cases with a diagnosis after the age of 2 died of tumors. Semen analysis in two patients showed normospermia. CONCLUSION: In the present study, the most common testicular tumors were yolk sac tumors and the patients diagnosed before 2 years of age showed favorable results. Age could be a relapse risk factor in yolk sac tumors. Guidelines for handling testicular tumors in children is not yet well established in Japan. An organized system seems necessary to gather and accumulate the results of the cases in Japan in order to develop better guidelines for treatment.     

Radio-frequency ablation of renal cell carcinoma in patients who were at significant risk

OBJECTIVE: Although radio-frequency ablation (RFA) has been recently applied as a minimally invasive treatment option for renal cell carcinoma (RCC), indication of this modality remains a critical issue due to the lack of complete tumor destruction as well as the uncertainty of its long-term efficacy. We report the efficacy of RFA for nine carefully selected patients with RCC who had significant reason to avoid invasive surgical treatment under general anesthesia. METHODS: Radio-frequency ablation was performed under epidural or local anesthesia by ultrasound or computed tomography (CT) guidance in nine patients with biopsy proven RCC (mean diameter, 38 mm; range, 20-53 mm), who were at significant operative or anesthetic risk for invasive surgery. Follow-up enhanced CT scans or magnetic resonance images were evaluated every 3-6 months and an evaluation of metastasis was performed every 6 months. RESULTS: At a mean follow-up of 17 months, seven (78%) of the nine patients with renal tumor showed no tumor enhancement. The renal function of all patients was well preserved. All patients were able to continue undergoing their respective treatments for active diseases in other organs in parallel to the RFA treatment. No distant metastasis, urine leakage were reported and one case of temporary hematuria and one case of peri-renal hemorrhage not requiring blood transfusion were encountered. Intra-operative ultrasonography was useful in the real-time monitoring of the minimally excessive extension of ablation into the normal parenchyma. CONCLUSION: Radio-frequency ablation appears to be an effective and safe minimally invasive therapeutic option for selected patients with RCC who have reason to avoid invasive surgery under general anesthesia.     

Experience of the treatment with gemcitabine, docetaxel, and carboplatin (GDC) chemotherapy for patients with small-cell carcinoma of the prostate

Small-cell carcinoma of the prostate (SCCP) is a rare entity. Many treatment modalities have been done, but thus far no uniform treatment has been clearly established. We carried out combination chemotherapy with gemcitabine, docetaxel, and carboplatin (GDC) regimen (for two patients with refractory SCCP. Case 1 involved a 53-year-old man diagnosed with SCCP after receiving hormone therapy for prostate cancer (stage D1). Six cycles of GDC chemotherapy was applied. Initially the primary site reduced according with a decline of neuro-specific enolase and with relief of the symptoms; however, bone disease occurred and he died of cancer 13 months after diagnosis of SCCP. Case 2 involved a 69-year-old man complaining of severe anal pain. He underwent a biopsy and a huge prostate tumor showing SCCP was showed. He had pelvic node metastases but no distant lesions, and received four cycles of GDC chemotherapy. He was discharged after receiving subsequent radiotherapy and remained stable for a while; however, he died of possible drug-induced hepatitis. This is the first report of chemotherapy with GDC against patients with SCCP. This regimen raised the possibility that it would intensify the outcome, which had been poorly achieved.     

Significant relationship of time-dependent uroflowmetric parameters to lower urinary tract symptoms as measured by the International Prostate Symptom Score

AIMS: The aim of the present paper is to elucidate the possible involvement of time-dependent parameters as obtained by uroflowmetry in the manifestation of lower urinary tract symptoms (LUTS) in elderly patients. METHODS: Using simple and multiple regression analyses, the correlation of the International Prostate Symptom Score (IPSS) with objective parameters including age, postvoid residual, uroflowmetry and transrectal ultrasonic measurements of the prostate was analyzed in 206 male patients (average age of 68.0 +/- 7.4 years) who visited our outpatient clinic complaining of LUTS. RESULTS: In the 206 patients, the mean maximum flow rate was 12.2 mL/s (13.7 mL/s in mild, 11.9 mL/s in moderate, and 11.2 mL/s in severe IPSS total score) and average flow rate was 4.4 mL/s (5.4 mL/s in mild, 4.3 mL/s in moderate, and 3.5 mL/s in severe IPSS total score). Simple regression analyses demonstrated that age, voiding time, and average and maximum flow rates correlate significantly with symptom scores. In particular, relatively strong relationships were found between average flow rate and scores of intermittency, weak stream and total and voiding symptoms scores. Serum prostate specific antigen level, postvoid residual and prostatic ultrasonic measurements did not show a significant correlation with symptom scores. Multiple regression analyses revealed age and average flow rate to be independent determinants for symptom scores. These results suggest that the time-dependent function in micturition interferes in the manifestation of LUTS in elderly men who have borderline or pathologic maximum flow rate. When evaluating uro flowmetry in elderly male patients with LUTS, attention should be paid to time-dependent parameters such as voiding time and average flow rate.     

Barbital Sodium, a Tumor Promoter for Kidney Tubules, Urinary Bladder, and Liver of the F344 Rat, Induces Persistent Increases in Levels of DNA Synthesis in Renal Tubules but Not in Urinary Bladder Epithelium or Hepatocytes

The nephrotoxicity of barbital sodium (NaBB), a renal and urinarybladder tumor promoter, was investigated in male F344/NCr rats.In an 8-week toxicity study, NaBB was administered to 6-week-oldmale rats for 8 weeks at dietary levels of 16,000, 8000, 4000,2000,1000, or 0 ppm. Rats tolerated NaBB at levels of 4000 ppm andbelow with no weight depression or mortality. liver-to-bodyweight ratios, however, were significantly increased at 4000ppm, and toxic renal lesions were observed histologically. Lightmicroscopic studies of male rats fed 1000 ppm NaBB for 2–52weeks or 4000 or 8000 ppm for 8 weeks revealed elevated levelsof DNA synthesis in renal tubular cells as measured with tritiatedthymidine autoradiography or 5-brome-2'-deoxyuridine immunohistochemistrythat were associated with degenerative and regenerative nephrotoxiclesions Increased labeling indices of urothelium and hepatocyteswere not seen in rats exposed to 1000 ppm NaBB which is effectiveas a bladder and liver tumor promoter at these doses. Thesestudies provide evidence for the chronic nephrotoxicity andrenal tubular hyperplasia induced by NaBB in F344 rats, whichare associated with the tumor-promoting activity of NaBB atthe doses studied. Hyperplasia in the urinary bladder or liverwas not found, however, for this bladder and liver tumor promoter.The conflicting findings in liver, bladder, and kidney are discussed.     

Hepatotoxicity of Agents That Enhance Formation of Focal Hepatocellular Proliferative Lesions (Putative Preneoplastic Foci) in a Rapid Rat Liver Bioassay

Hepatotoxicity of Agents That Enhance Formation of Focal HepatocellularProliferative Lesions (Putative Preneoplastic Foci) in a RapidRat Liver Bioassay. WARD, J. M., TSUDA, H., TATEMATSU, M., HAGIWARA,A., AND ITO, N. (1989). Fundam Appl Toxicol. 12., 163–171.The histopathology of hepatic toxicity for 58 chemicals previouslytested in a rapid rat liver bioassay for demonstrating potentialhepatocellular carcinogens and/or tumor promoters was reviewed.Rats received the test diet for 1 week prior to partial hepatectomyand for an additional 5 weeks thereafter at doses near the estimatedmaximally tolerated dose. These rats served as controls forothers receiving initiation by N-nitrosodiethylamine (DEN) andthe test diets. Twenty-two of these chemicals were previouslyfound to enhance the formation of glutathione S-transferase,placental form (GST-P)-positive putative preneoplastic hepatocellularfoci (promoters) following DEN initiation in this rapid bioassay,whereas 36 chemicals did not. Of the agents that promoted GST-P-positivefoci, 14/22 (63.6%) produced toxic hepatocyte lesions whileonly 4/36(11.1%) of the nonpromoters did so at the doses used.Biliary toxicity was found for 7/22 (31.8%) of the promotersand 6/36 (16.7%) of the nonpromoters. Only 2/13 (15%) chemicalsthat inhibited GST-P-positive foci produced hepatic toxicity.Thus, agents that were presumed hepatic tumor promoters characteristicallywere hepatotoxins while nonpromoters of carcinogenesis werenot hepatotoxins in this rapid rat liver bioassay.     

Effects of mineralocorticoid and angiotensin II receptor blockers on proteinuria and glomerular podocyte protein expression in a model of minimal change nephrotic syndrome

Aim: Several proteins constituting the slit diaphragm are considered important for maintaining capillary wall permselectivity. Early intervention with blockers of angiotensin II receptors (AR) and mineralocorticoid receptors (MR) is effective against proteinuria in models of chronic hypertensive and protein‐induced renal damage. However, the effects of AR and/or MR blockers in a model of acute nephrotic syndrome remain unknown. The effects of AR and MR blockers were examined in puromycin aminonucleoside (PAN)‐treated rats. Methods: Six week old male Sprague–Dawley (SD) rats were injected with PAN or vehicle and assigned to groups as follows: vehicle (group C); PAN (group P); PAN followed 3 days later by administration of the MR blocker, eplerenone (group MR), and by the AR blocker, losartan (group AR). Blood pressure and urinary protein excretion were measured and all rats were killed for immunohistochemical investigation on day 14 after PAN administration. Results: Blood pressure did not change throughout the study period. Proteinuria was decreased in groups MR and AR compared with group P (on day 14 after PAN administration, respectively; group P vs AR, P < 0.01; group P vs MR, P < 0.05). Nephrin, podocin and podocalyxin staining was preserved in the glomeruli of groups MR and AR compared with group P. Conclusion: The MR and AR blockers decreased proteinuria in the acute model of nephrotic syndrome with preserved expression of glomerular podocyte protein independently of blood pressure.