Seminal inhibin--prospects for immunocontraception.

Passive immunization of adult rats, hamsters and marmosets with rabbit anti-seminal inhibin resulted in complete or partial block of fertility. The antiserum treatment presumably neutralized endogenous inhibin resulting in an unopposed rise in circulating FSH. This probably led to a refractoriness of the testes to FSH resulting in complete spermatogenic arrest. Nevertheless, there was no change in the mating behaviour of the animals. The antibodies also affected the epididymal spermatozoa by causing large scale agglutination.     

Cystinotic and normal fibroblasts: Differential susceptibility to cysteine toxicity in vitro

Summary Extracellular cysteine concentrations between 0.5 and 2.5 mM resulted in death of normal but not cystinotic cells grown in Eagle's minimal essential medium containing supplemental fetal bovine serum and antibiotics. Differential cell survival was determined by viable cell counting using Trypan Blue dye exclusion. In cocultivation experiments of [³H]thymidine-labelled cystinotic fibroblasts with nonradioactive normal fibroblasts, autoradiography confirmed the selective survival of cystinotic cells in medium containing 1 mM cysteine. At this concentration of 1 mM cysteine, intracellular cystine content increased slightly in surviving normal cells but not in cystinotic cells, which normally contain a high level of intracellular cystine. This comparative resistance of cystinotic fibroblasts to elevated extracellular cysteine concentrations forms the basis for an in vitro selective system for these mutant human cells. Further exploration of this resistance phenomenon may well expand the understanding of the molecular defect in cystinotic cells.     

Decrease in glutathione levels of kidney and liver after injection of methionine sulfoximine into rats

After rats were injected with the convulsant methionine sulfoximine, there was a rapid decrease in the glutathione concentrations of the kidney and liver, but there was no measurable effect (within 5 hours) on brain glutathione. The maximum decreases in the glutathione concentrations of kidney and liver were observed 1 hr after injection and were about 60 and 40%, respectively, of the control levels. The findings suggest that there may be at least two pools of tissue glutathione. Studies in which other amino acids were injected, and earlier $\text{in vitro}$ studies, are consistent with the conclusion that methionine sulfoximine affects glutathione synthesis $\text{in vivo}$ by inhibiting γ-glutamylcysteine synthetase. Injection of glycylglycine also decreased glutathione levels, an effect probably mediated by γ-glutamyltranspeptidase.     

Role of Interaction and Nucleoside Diphosphate Kinase B in Regulation of the Cystic Fibrosis Transmembrane Conductance Regulator Function by cAMP-Dependent Protein Kinase A

Cystic fibrosis results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent protein kinase A (PKA) and ATP-regulated chloride channel. Here, we demonstrate that nucleoside diphosphate kinase B (NDPK-B, NM23-H2) forms a functional complex with CFTR. In airway epithelia forskolin/IBMX significantly increases NDPK-B co-localisation with CFTR whereas PKA inhibitors attenuate complex formation. Furthermore, an NDPK-B derived peptide (but not its NDPK-A equivalent) disrupts the NDPK-B/CFTR complex in vitro (19-mers comprising amino acids 36–54 from NDPK-B or NDPK-A). Overlay (Far-Western) and Surface Plasmon Resonance (SPR) analysis both demonstrate that NDPK-B binds CFTR within its first nucleotide binding domain (NBD1, CFTR amino acids 351–727). Analysis of chloride currents reflective of CFTR or outwardly rectifying chloride channels (ORCC, DIDS-sensitive) showed that the 19-mer NDPK-B peptide (but not its NDPK-A equivalent) reduced both chloride conductances. Additionally, the NDPK-B (but not NDPK-A) peptide also attenuated acetylcholine-induced intestinal short circuit currents. In silico analysis of the NBD1/NDPK-B complex reveals an extended interaction surface between the two proteins. This binding zone is also target of the 19-mer NDPK-B peptide, thus confirming its capability to disrupt NDPK-B/CFTR complex. We propose that NDPK-B forms part of the complex that controls chloride currents in epithelia.     

Cytokine gene polymorphisms are associated with risk of urinary bladder cancer and recurrence after BCG immunotherapy

The association of interleukin-1β (IL-1B) -511C?>?T and IL-1 receptor antagonist (IL-1RN) VNTR, transforming growth factor-β (TGF-B1) +28C?>?T and interferon-γ (IFN-G)?+?874T>A polymorphisms with bladder cancer (CaB) susceptibility and risk of recurrence in Bacillus Calmette–Guérin (BCG)-treated patients was analyzed in 287 controls and 213 CaB patients (73 BCG treated). Increased risk was observed with the IL-1RN*2 allele (odds ratio (OR) 5.01) and the IFN-G +874 A allele (OR 1.78). TGF-B TT and IFN-G +874 A carriers were associated with reduced (hazard ratio (HR) 0.37) and enhanced (HR 2.24) risk of recurrence after BCG immunotherapy, respectively. The study suggests that cytokine gene variants may modulate CaB susceptibility and risk of recurrence after BCG immunotherapy.     

Testicular phosphatase activity in rats treated with cyproterone acetate & flutamide

Cyproterone acetate (CPA) and flutamide (F), 2 antiandrogens were tested in the rat, to determine their effect on acid (ACP) and alkaline (ALP) phosphatase activity. 70 fertile male rats were injected with either CPA, F, or testosterone propionate (TP) at either 2.5 or 10 mg. TP was injected either alone or in combination with the others. Histological examinations of the testes were performed. Spermatogenesis was arrested and Leydig cells atrophied in animals treated with CPA or F. Histochemical examination revealed that CPA enhanced ALP and ACP in the testes while F decreased ALP and ACP. TP treatment in combination with either antiandrogens was unable to overcome their effect. The changes in the 2 phosphatases depending on which antiandrogen was injected suggests different modes of action.