Biomedical subjects
Publications and source records attributed to M Baba.
A 41-year-old Japanese female developed polyarthritis with fusiform deformity. Diagnosis of rheumatoid arthritis was made and anti-inflammatory drugs were prescribed. Later thrombophlebitis in legs and cardiac lesions developed. The clinical course and treatment of this patient are briefly discussed.
Administration of anti-cholinesterase before operation and high doses of prednisolone after the operation are commonly prescribed in cases of thymectomy for the treatment of myasthenia gravis. Our policy is to carry out an extended thymectomy combined with pre- and post-operative administration of prednisolone on alternate days. Our method was used in the treatment of 50 patients with generalized myasthenia gravis, from January 1979 to December 1984. The results were examined in conjunction with the necessity for preoperative administration of an anti-cholinesterase preparation and also with factors influencing the follow-up result and postoperative process. This method made it feasible to perform surgery under conditions of stabilization of clinical symptoms and satisfactory postoperative management. A postoperative period of unstable symptoms could thus be avoided. The palliation rate at one year after the operation was 96 per cent, while the remission rate at 5 years after the operation was 70 per cent. The preoperative supplement of anti-cholinesterase and preoperative per cent forced vital capacity were considered to be predictive factors concerning the necessity of artificial respiration.
To evaluate the clinical efficacy of magnetic resonance imaging (MRI) of lumbosacral lipomas, the magnetic resonance images of nine patients were reviewed. T1- and T2-weighted spin echo sequences were used with a 0.5-T magnetic resonance system. The tethered or low-positioned conus medullaris, the lipoma itself, the lipoma--cord interface, the subarachnoid space, and hydromyelia were clearly disclosed. The nerve rootlets were not as clear. These results indicate the possible discontinuance of myelography and metrizamide computed tomography (CT) cisternography for such imaging. The diagnostic modalities of choice for lumbosacral lipoma imaging are plain spine films, plain CT scan, and MRI.
Glycyrrhizin (GL), one of the plant extracts, was investigated for its antiviral action on the human immunodeficiency virus [HIV (HTLV-III/LAV)] in vitro, using cytopathic effect and plaque forming assay system in MT-4 cells (a HTLV-I-carrying cell line). Cloned Molt-4 cells (clone No. 8), which are sensitive to HIV and fuse to giant cells after infection, were also used as a parameter for cytopathic effect of HIV. GL completely inhibited HIV-induced plaque formation in MT-4 cells at a concentration of 0.6 mM, the 50% inhibitory dose being 0.15 mM. GL completely inhibited the cytopathic effect of HIV and the HIV-specific antigen expression in MT-4 cells at a concentration of 0.3 and 0.6 mM, respectively. Furthermore, GL inhibited giant cell formation of HIV-infected Molt-4 clone No. 8 cells. GL had no direct effect on the reverse transcriptase of HIV. Its mechanism of anti-HIV action remains to be elucidated.
The polyanionic substances dextran sulfate and heparin were investigated for their antiviral effect on the human immunodeficiency virus (HIV) in vitro. Dextran sulfate and heparin effected a 50% reduction in the cytopathogenicity of HIV for MT-4 cells at a concentration of 4.7 and 7.5 micrograms/ml, respectively. In Molt-4 (clone 8) cells, these values were slightly higher (14.1 and 15.6 micrograms/ml, respectively). No toxicity for the host cells was noted with these compounds at a concentration up to 400 micrograms/ml, so that the selectivity indexes, as based on the ratio of the 50% cytotoxic dose to the 50% antiviral effective dose, were well in excess of 100. These findings may have far reaching implications both diagnostically, when attempts are made to isolate HIV from heparinized blood samples, as therapeutically, to the extent that dextran sulfate or heparin may be useful in blocking HIV replication in vivo.
One of the plant extracts, glycyrrhizin (GL) was investigated for its antiviral action on varicella-zoster virus (VZV) in vitro. When human embryonic fibroblast (HEF) cells were treated with GL after inoculation of virus (post-treatment), the average 50%-inhibitory dose (ID50) for five VZV strains was 0.71 mM, and the selectivity index (ratio of ID50 for host-cell DNA synthesis to ID50 for VZV replication) was 30. GL was also effective against VZV replication when HEF cells were treated 24 h before the inoculation (pretreatment). Furthermore, at a concentration of 2.4 mM GL inactivated more than 99% of virus particles within 30 min at 37 degrees C. In combination with other anti-herpes drugs (acyclovir, adenine arabinoside, bromovinyldeoxyuridine, and phosphonoformate) or human native beta-interferon, GL had an additive or slightly synergistic effect on VZV replication. The mechanism of anti-VZV action is still unclear. We postulate that GL inhibits the penetration, uncoating or release of virus particles.
Various 3-hydroxy-2-phosphonylmethoxypropyl (HPMP) and 2-phosphonylmethoxyethyl (PME) derivatives of purine [adenine (A), guanine (G), 2,6-diaminopurine (DAP), 2-monoaminopurine (MAP), hypoxanthine (HX)] and pyrimidine [cytosine (C), uracil (U), thymine (T)] have been evaluated for their antiviral properties. PMEDAP, (S)-HPMPA [and the cyclic phosphonate thereof, (S)-cHPMPA)], (S)-HPMPC, PMEG, PMEA, HPMPG and HPMPDAP proved to be effective inhibitors of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). (S)-HPMPA and (S)-cHPMPA were the most effective inhibitors of varicella-zoster virus (VZV), and (S)-HPMPC was the most effective inhibitor of cytomegalovirus (CMV). Against adenovirus (types 2, 3 and 4) and vaccinia virus again (S)-HPMPA and (S)-cHPMPA showed the greatest inhibitory activity. As a rule, the PME derivates were much less inhibitory to VZV, CMV, vaccinia and adenovirus than the HPMP derivatives. However, PMEA, PMEDAP and PMEMAP showed marked and selective activity against the human immunodeficiency virus (HIV). (S)-HPMPA was selected for further evaluation in animal model infections. It proved efficacious in the topical treatment of HSV-1 keratitis in rabbits and cutaneous HSV-1 infection in hairless mice, and in the systemic treatment of both HSV-1 and vaccinia virus infections in mice.
A series of 2',3'-unsaturated and 3'-substituted 2',3'-dideoxynucleoside analogues of purines and pyrimidines have been synthesized and evaluated for their inhibitory activity against human immunodeficiency virus (HIV). The 2',3'-unsaturated analogues of 2',3'-dideoxycytidine (ddeCyd) and 2',3'-dideoxythymidine (ddeThd), 3'-azido-2',3'-dideoxythymidine (AzddThd), 3'-fluoro-2',3'-dideoxythymidine, 2',3'-dideoxycytidine (ddCyd), and 2',3'-dideoxyadenosine (ddAdo) emerged as the most potent inhibitors of HIV-induced cytopathogenicity in the human T lymphocyte cell lines ATH8 and MT4. In ATH8 cells ddCyd, ddeCyd, and ddAdo had the highest therapeutic index whereas in MT4 cells AzddThd, ddThd, ddCyd, and ddAdo were the most selective. Derivatives from ddThd in which the substituent group was linked to the 3'-carbon atom via a thio, sulfonyl, or oxygen bridge were far less inhibitory to HIV than was AzddThd.
A systematic synthesis was undertaken of 2',3'-dideoxyadenosine analogues with either an azido, fluorine, or hydroxyl group substituted in the "up" or "down" position of C-2 or C-3 of the sugar moiety. The compounds were evaluated against the cytopathogenicity of human immunodeficiency virus (HIV) for MT-4 cells. The four azido derivatives 6, 7, 8, and 9 were synthesized by a nucleophilic displacement reaction with lithium azide on the mesylates 3, 2, 5, and 4. (Diethylamido)sulfur trifluoride was used for the synthesis of 10-12. The compound 13 was obtained by 2'-deoxygenation of 9-(3-fluoro-3-deoxy-beta-D-xylofuranosyl)adenine. Among the azido derivatives, compound 8 with the 3'-azido "down" was slightly more active than 2',3'-dideoxyadenosine (1) but considerably more toxic, and, of the fluorine series, compound 11, with the 2'-fluoro "up", was the most selective inhibitor of HIV, although it was less active than 1. Hence, none of the newly synthesized compounds proved more selective in their anti-HIV activity than the parent compound, 1.
Protoplasts of Candida albicans were prepared by digestion with Zymolyase and the effect of aculeacin A, a wall-active antibiotic, on the synthesis of microfibrillar structures by the protoplasts incubated for 5 hr in an osmotically stabilized medium was studied using several electron microscopical techniques. Chemical analyses of the protoplasts before and after reversion with or without the antibiotic were also performed. Aculeacin A not only inhibited synthesis of microfibrils mainly composed of alkali-insoluble beta-glucan, but also their assembly to form thicker bundles. The antibiotic appeared to have no effect on other wall components constituting the surface structure of reverting protoplasts. These data confirmed our previous postulation that aculeacin A is a specific and potent inhibitor of beta-glucan synthesis as well as biogenesis of cell walls including beta-glucans in susceptible yeasts.
Explore the source record for details and available documents.
The combined antiviral effects of various 2',3'-dideoxynucleosides and ribavirin on the replication of human immunodeficiency virus type 1 in MT-4 cells have been examined. Ribavirin antagonized the antiviral activity of the pyrimidine 2',3'-dideoxynucleosides (3'-azido-2',3'-dideoxythymidine, 2',3'-dideoxythymidin-2'-ene, 2',3'-dideoxycytidine, and 2',3'-dideoxycytidin-2'-ene), but enhanced the antiviral activity of the purine 2',3'-dideoxynucleosides (2',3'-dideoxyadenosine and 2',3'-dideoxyguanosine). Combinations of the 2',3'-dideoxynucleosides with each other were also examined. These combinations resulted in an additive to subsynergistic effect.
The inhibitory effects of 20 selected antiviral compounds on the replication of adenoviruses (types 1 to 8) in vitro were investigated. While 18 compounds were ineffective, 2 compounds, namely (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA] and 9-[(2-hydroxy-1,3,2-dioxaphosphorinan-5-yl)oxymethyl]guanine P-oxide (2'-nor-cyclic GMP), were highly effective against all adenovirus types assayed in human embryonic fibroblast cultures. Their 50% inhibitory doses were 1.1 microgram/ml for (S)-HPMPA and 4.1 micrograms/ml for 2'-nor-cyclic GMP. They were nontoxic for the host cells at the effective antiviral doses.
Explore the source record for details and available documents.
A case of a 19-year-old man with a right parasellar chondroma examined with computed tomography (CT) and nuclear magnetic resonance (NMR) scan is reported. The literature about CT and NMR scan findings of intracranial chondroma is reviewed. Typical CT findings are a round, high density mass with calcification, that is only slightly enhanced by contrast medium.
Relationships between theophylline concentrations in saliva and serum and lung functions were investigated in 27 asthmatic children receiving a sustained-release theophylline. Improvements in lung functions were related to increasing theophylline concentrations. The concentration required to maintain normal lung functions was 10 micrograms/ml in serum and 7 micrograms/ml in saliva. Theophylline concentrations in serum and saliva statistically correlated (r = 0.949). The mean serum - saliva ratio was 1.45 +/- 0.02, with a 13.7% intersubject and a 14.9% intrasubject variation. Predicted serum concentrations were +/- 2 micrograms/ml of measured concentrations in 92 samples (92%). From the results, theophylline concentrations in saliva may be useful in predicting serum values.
Explore the source record for details and available documents.
Explore the source record for details and available documents.