Assembly, disassembly, and exchange of glial fibrillary acidic protein

The kinetics and dynamics of glial fibrillary acidic protein (GFAP) assembly was explored by a fluorescence energy transfer assay method. Purified GFAP was stoichiometrically labeled at a single cysteine residue with fluorescein-maleimide. Soluble labeled GFAP in a low ionic strength buffer was assembled into 10 nm filaments by rapidly increasing the ionic strength, and the kinetics of GFAP assembly was monitored by the reduction in fluorescence due to self-quenching of fluorescein. The extent of fluorescence quench correlated with both the formation of 10 nm filament morphology and the amount of protein pelleted at 12,000g. The assembly of GFAP is critically dependent upon both protein and magnesium ion concentration, and at the critical concentration for GFAP assembly is approximately 40 micrograms/ml. Disassembly of GFAP filaments was also observed as a relief of fluorescence quenching after dilution of labeled GFAP filaments. When labeled GFAP filaments were mixed with an excess of unlabeled filaments, a rapid increase of fluorescence was observed, which is due to an exchange of subunits between labeled and unlabeled GFAP filaments. These results indicate that GFAP filaments are dynamic structures and that a small pool of kinetically active unassembled GFAP subunits are in a dynamic equilibrium with assembled GFAP filaments. The ability of GFAP to assemble, disassemble, and undergo subunit exchange has important implications for the organization and dynamics of astroglia cell cytoskeleton during development and in response to injury.     

Reduction of Nitric Oxide with L–/Vc–Monomethyl Arginine in lnterleukin–2 and Anti–CD3 Monoclonal Antibody Combination Therapy

We evaluated nitric oxide induction in antitumor therapy consisting of anti–CD3 monoclonal antibody (anti–CD3) and interleukin–2 (IL–2), then determined the effect of nitric oxide reduction with L–N^G–monomethyl arginine (LNMA) on the therapeutic methods. Female C57BL/6 mice, MCA102 (a non immunogenic, NK–resistant murine fibrosarcoma cell line), and 145–2C11 (hamster anti–murine–CD3 mAb) were utilized in an experimental hepatic metastasis model developed by injecting a tumor cell suspension into the spleen of mice. A marked increase in serum NO₂^–+ NO₁ was observed at 19 hours after anti–CD3 (10 μ, IV) and additional IL–2 administrations (40times10¹ U, twice, If) induced a further increase. The NO₂, + NO_3- elevation in spot urine in the combination therapy was not suppressed with LNMA at a dose of 100 μg/h but was significantly lowered at 300 μg/h. The efficacy of the anti–CD3 + IL–2 therapy was not diminished by LNMA administration either at 100 μg/h or at 300 μg/h.     

Prophylactic effect of UFT on the recurrence of bladder cancer

To evaluate the effect of UFT, a mixture of ftorafur and uracil in a ratio of 1:4, in preventing postoperative recurrence of bladder cancer, we performed a randomized controlled study with a non-medication group as control. UFT was given orally 400 mg a day for 6 months. Of 111 patients, 56 were given UFT and 55 were followed up without any medication. The non-recurrence rate in the group treated with UFT was 62.8% after 1 year and 36.3% after 2 years of follow up, and that of the control group was 45.7% and 39.5%, respectively. The rate of non-recurrence in the UFT group was significantly higher (p less than 0.05) than that of the control group during the period of follow up for 2 years. The incidence of side effects was 6.8% in UFT patients. These results indicate the clinical usefulness of prophylactic administration of UFT for bladder cancer patients.     

Skullbase-penetrating injuries caused by umbrella tips: case reports

Two cases of skullbase-penetrating injuries caused by umbrella tips are reported. Case 1: 24-year-old male. Admitted with disturbance of consciousness, left hemiparesis, nasal bleeding, and laceration of left lower eyelid because of having been stabbed by an umbrella tip. Pupils and fundi revealed no definite findings. Plain skull X-ray showed turbid ethmoid sinus and fracture of planum sphenoidale. Cranial CT showed right putaminal hematoma with intraventricular hemorrhage and pneumocephalus. Increased ICP necessitated surgery two days after the injury. Dural laceration of planum sphnoidale, laceration of left optic nerve, right rectal gyrus contusion and rebleeding from the right lenticulostriate branch were observed. Dural plasty and removal of hematoma with external decompression were carried out. He had a good postoperative course, but left visual loss and left hemiparesis remained. Case 2: 29-year-old male. Admitted with excoriation of his right nostril because of having been stabbed by an umbrella tip, severe headache, and nasal discharge. Oculomotor palsy was observed as well as CSF rhinorrhea and meningeal irritability. Plain skull X-ray showed niveau in sphenoidal sinus, pneumocephalus, and fracture of sella turcica. His complaint disappeared after conservative therapy. We reviewed the literature and found only 4 similar cases. The skullbase, because of its anatomical character, is likely to be penetrated in orbital and periorbital injury caused by umbrella tips. Cases which include disturbance of consciousness have a poor prognosis. We hope the fact that umbrella tips can easily become life-threatening objects will come to the attention of the general public so that similar cases may be avoided.     

Curing effects of chlorination, ozone and UV treatments on plasmid DNAs

Curing effects of chlorine, ozone and ultraviolet (UV) on plasmid DNAs were investigated as one of the measures of bio-hazards due to recombinant plasmids. For donor strains of plasmids, Pseudomonas aeruginosa RM 2046 harboring the self-transmissible plasmid R68 and RM 2021 harboring the cloning vector R1162, Escherichia coli C 600 ML 4903 and ML 1410 harboring the self-transmissible plasmid Rts-1 and RP4, and E. coli JM 109 harboring the cloning vector pBR 322 were used. The curing rate showed a tendency to increase with treatment time in a L-shaped curve for each plasmid DNA. The rates reached steady state after more than 5-10 minutes of the chlorination and ozone treatment, or 5-10 seconds of the UV treatment, independent of the treatment intensity. It became clear by use of replica technique that effective curing took place by chlorination for Rts-1, R1162 and pBR322, by ozone treatment for R68, and by UV treatment for PR4, respectively. Of the three disinfection treatments excellent curing effect occurred with chlorination, as more than 90% of the curing rate was obtained by that treatment for all donor strains.     

Binding profile of SM-9018, a novel antipsychotic candidate

The present study employed various receptor-binding assays to clarify the biochemical characteristics of SM-9018. SM-9018 possessed very high affinity for 5-HT2, D2 and 5-HT1A receptors (Ki = 0.61, 1.4 and 2.9 nM, respectively), and it had moderate affinity for alpha 1 and D1 receptors (Ki = 17 and 41 nM, respectively). However, SM-9018 had only negligible affinity for alpha 2, opiate, glutamate, phencyclidine, benzodiazepine and GABAA receptors. These results suggest that SM-9018 may be a novel antipsychotic agent with binding affinity for 5-HT2 and 5-HT1A receptors.     

Ultrastructural characterization of the tau-immunoreactive tubules in the oligodendroglial perikarya and their inner loop processes in progressive supranuclear palsy

Coiled bodies and interfascicular threads are conspicuous white matter abnormalities of brains of patients with progressive supranuclear palsy (PSP). Both structures are argyrophilic and immunoreactive for the microtubule-binding protein tau. This report concerns the ultrastructural localization of interfascicular threads and their relationship to coiled bodies in five PSP patients. We showed for the first time that abnormal tubules with a 13- to 15-nm diameter and fuzzy outer contours were the common structures of coiled bodies in the oligodendroglial perikarya and of interfascicular threads. Moreover, the tubules were immunolabeled by anti-tau antibodies. The abnormal tau-positive tubules of interfascicular threads were located in the inner loop of the myelin sheath. Our study further indicated that the thread-like structures in the white matter comprised, at least in part, oligodendroglial processes, and that they were also present in gray matter. We consider that the formation of coiled bodies in the perikarya and of interfascicular threads represents a common cytoskeletal abnormality of the oligodendroglia of PSP patients. Moreover, even though the white matter alterations of PSP resemble those of corticobasal degeneration, there are certain ultrastructural differences in the abnormal oligodendroglial tubules of the two diseases. Received: 4 October 1996 / Accepted: 6 December 1996     

Testicular macromolecular synthesis in men with varicocele.

The synthesis of DNA, RNA, and protein by varicocele testes with spermatogenic dysfunction was studied by examination of the levels of incorporation of [3H]thymidine, [14C]uridine, and [14C]leucine into the testicular tissue at 31 degrees C in vitro. The results suggest that DNA synthesis by the testis with moderate tubular damage is impaired whereas synthesis of RNA and protein is not. The cell regenerative ability of the testis with moderate tubular damage may be poor in spite of the preservation of testicular cell RNA and protein synthesis.