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Biomedical subjects

K Mochizuki

Publications and source records attributed to K Mochizuki.

At least 145 records · Page 8Linked to original sources
PubMed1990

Susceptibility of Mongolian gerbils (Meriones unguiculatus) to leptospires and the protective effect of vaccination.

Mongolian gerbils, Meriones unguiculatus, were shown to be highly susceptible to Leptospira interrogans serovars such as icterohaemorrhagiae, copenhageni, canicola, autumnalis, javanica, pyrogenes and hebdomadis as compared to guinea pigs and hamsters. Mortality with signs of haemorrhage and jaundice was recorded in all experimental rodents after intraperitoneal inoculation with all strains of the serovars indicated. However, Mongolian gerbils were comparatively susceptible to strains which were of low virulence to guinea pigs and hamsters. Use of leptospiral vaccination proved effective in protecting the animals against inoculum challenges. The Mongolian gerbil is a species that may be selectively and preferentially useful for assays on the protective effects of leptospiral vaccination.

Animals↗
PubMed1990

[Experimental studies of direct pulp capping in permanent teeth with incompletely formed apices].

In permanent teeth described as having incompleted roots, dentin is still in the process of deposition on internal dentin walls and the root is in the process of completion. The purpose of this study of dog's immature permanent teeth was to investigate pulp healing and continuous root and internal dentin-wall developments after direct pulp capping with two types of calcium hydroxide paste on mechanically exposed pulp. Material and methods In this study, 148 vital permanent premolars with incompletely formed apices were obtained from 26 dogs (6 months old). The animals were generally anesthetized with 5% sodium pentobarbital, and a cavity was prepared on the occlusal surface of each experimental tooth using an air turban handpiece with diamond bur. After the cavity preparation, the central pulp horn of each tooth was mechanically exposed with a sterile round bur (ISO No. 007, 2/0). In experimental teeth on the right side, a calcium hydroxide-iodoform paste "Calvital" was applied on the exposed pulp, in experimental teeth on the left side, the exposed pulp was capped with a hard-setting calcium hydroxide paste "Dycal". The cavities were lined with first a zinc-oxide eugenol cement and then a zinc-phosphate cement. Then the cavities were filled with silver amalgam. The dogs were sacrificed by means of sodium pentobarbital at intervals of 3, 7, 14, 28, and 56 days after direct pulp capping. Their jaws and teeth were removed, fixed with formalin, and 100 cases out of 148 teeth with bones from 20 dogs were decalcified, and embedded in celloidin. Each specimen was serially sectioned, stained with hematoxylin-eosin, thionin-picric acid and van Gieson's stain, and evaluated microscopically. In order to identify postoperative dentin formation, intravenous injections of tetracycline were administered to the remaining 6 dogs (48 teeth) at various intervals after the experimental procedure. Two dogs were sacrificed each of the experimental periods. Specimens were embedded in resin and sectioned to a thickness of 50 microns. Undecalcified ground sections were observed by contact microradiography, and tetracycline labeling was evaluated by ultraviolet light. Results and Conclusion 1. Pathological evaluations of the 2 groups "Calvital" group: 49 (98.0%) of 50 cases were evaluated as good, and 1 case (2.0%) as moderately good. "Dycal" group: 31 (62.0%) of 50 cases were evaluated as good, 15 (30.0%) as moderately good, and 4 (8.0%) as bad.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Spatial fibre architecture of Mm. pectorales in macaques: their morphological, phylogenetical, and functional implications.

The pectoral muscles of the 2 monkeys, Macaca fuscata and M. fascicularis, were described particularly in the light of 3 dimensional fibre architecture. There existed throughout the muscles the rotation in the same direction and radiation of fibre bundles as well as the consecutive and multi-stratified structure; This architectural design suggested that the deep pectoral masses of the mammals were derived from the caudal portion of the primitive pectoral plane through fibre migration caused by the whole muscle rotation, probably in response to the functional necessity peculiar to the mammalian locomotion.

Animals↗
PubMed1990

Nontoxic concentration of ceftazidime and flomoxef sodium for intravitreal use--evaluated by in-vitro ERG.

The effects of ceftazidime (CAZ) and flomoxef sodium (FMOX) on the in-vitro electroretinogram (ERG) of albino rabbits were studied. The a-wave, the b-wave and the oscillatory potential (OP) were unchanged by 0.3mM (0.19mg/ml) CAZ-containing solution. The OP was suppressed by 0.5mM (0.32mg/ml) CAZ. The a-wave, the b-wave and the OP were unchanged by 0.5mM (0.26mg/ml) FMOX. The OP was suppressed and its peak latency was delayed by 2mM (0.52mg/ml) FMOX. The concentration of 0.3mM (0.19mg/ml) CAZ was higher than its minimum inhibitory concentration (MIC) against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Serratia marcescens and Propionibacterium acnes. The concentration of 0.5mM (0.26mg/ml) FMOX was higher than its MIC against Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens and Propionibacterium acnes.

Animals↗
PubMed1990

Electroretinographical changes due to antimicrobials.

We evaluated the retinal toxicity of antimicrobials (sulbenicillin, cefazolin, flomoxef, gentamicin, sisomicin, netilmicin, tobramycin, amikacin, vancomycin, ofloxacin, lomefloxacin, and miconazole) by the electroretinogram, before and after a single-shot intravitreal injection in rabbits. The clinical dosage for single-shot intravitreal injections which we recommend are 2 mg for sulbenicillin, 0.25 mg for cefazolin, 0.2 to 0.4 mg for flomoxef, 0.1 mg for gentamicin, 0.1 to 0.2 mg for netilmicin, 0.2 to 0.4 mg for amikacin, 0.2 mg for tobramycin, 1 mg for vancomycin, 0.2 mg for ofloxacin, 0.2 mg for lomefloxacin, and 0.05 mg for miconazole.

4-Quinolones↗
PubMed1990

[Pentatrichomonas hominis from beagle dogs--detection method, characteristics and route of infection].

Pentatrichomonas sp. from the feces of beagles was cultured axenically, and identified as P. hominis. The culture medium used was slightly modified Diamond's medium supplemented with chicken liver extract and rifampicin. Based upon good proliferation after inoculating only a few organisms in this medium, a fecal examination method employing cultivation was developed. Resistance of the trichomonad against disinfectants and metronidazole was tested, and it was found that the protozoan was rather susceptible. After oral administration of the organism to mice and rats, all the treated animals were infected. Since two types of the trichomonad, moving and non-moving, were detected, the presence of any type resistant to standing or drying was ruled out. A possible route of trichomonad infection to beagles is discussed.

Animals↗
PubMed1989

Serodiagnosis of cancer, using porcine antigens recognized by human monoclonal antibody, HB4C5.

Antigens, recognized by human monoclonal antibody (HB4C5) generated from a lung cancer patient, were found to occur in porcine pancreas. The antigens-I and -II were purified from crude trypsin of porcine pancreas, only by Mono Q column chromatography, and were eluted at 260 and 300 mM NaCl in 10 mM Tris-HCl buffer, pH 7.4, respectively. These antigens differed from trypsin in molecular weight, elution pattern from the Mono Q column, and their reactivity with HB4C5. The molecular weights of the two antigens were almost the same at around 35000. These were used for serodiagnosis with an assay system based on 96-well immunoplates. The reactivities of antigens-I and -II with various sera were similar. When the reactivity of IgG in serum with antigen-II was measured, absorbance at 415 nm in the case of normal and lung cancer patients was 0.178 +/- 0.056 and 0.492 +/- 0.136 (p less than 0.005). The rates of positive reaction in ovary, larynx, uterus, lung and liver cancers were more than 50%, but the rates in stomach and breast cancers were less than 30%. Positive reaction was hardly detected in pancreas cancer and normal controls.

Animals↗
PubMed1989

Productive ascites growth of heterohybridomas between Epstein-Barr virus-transformed human B cells and murine P3X63Ag8.653 myeloma cells.

Heterohybridomas between Epstein-Barr virus-transformed human B cells and murine myeloma P3X63Ag8.653 cells were found to produce sizable quantities of human monoclonal antibodies in nude mouse ascites. Mice injected intraperitoneally with two of such heterohybridomas yielded several milliters of ascites fluid which contained nearly 100-fold higher anti-platelet activities than those in routine culture supernatants.

Animals↗
PubMed1989

[Effects of aminoglycosides on the rabbit in-vivo ERG].

We evaluated the retinal toxicity of aminoglycosides (gentamicin, sisomicin, netilmicin, tobramycin and amikacin) by ERG, before and after a single-shot intravitreal injection in rabbits. Gentamicin 200 micrograms abolished the c-wave one week after injection, only slightly diminishing the b-wave and the oscillatory potentials (OPs). Gentamicin 80 micrograms did not alter the ERG up to at least 8 weeks after injection. All the ERG components examined were abolished by 200 micrograms and were irreversibly suppressed by 80 micrograms of sisomicin for the entire period of follow-up. Netilmicin (200 micrograms) or tobramycin (200 micrograms) transiently suppressed the b-wave, c-wave and the OPs. Amikacin (200 micrograms) caused no ERG changes for at least 8 weeks after injection. The clinical doses for single-shot intravitreal injections that we recommend are 100 micrograms for gentamicin, 200 micrograms for netilmicin, 200 micrograms for tobramycin and 200-400 micrograms for amikacin.

Aminoglycosides↗
PubMed1989

[Effects of vancomycin and ofloxacin on rabbit ERG in vivo].

The retinal toxicity of vancomycin and ofloxacin was studied by electroretinogram (ERG) before and after intravitreal injection in rabbits. Vancomycin is known to be effective on methicillin-resistant Staphylococcus aureus. A dose of 1mg vancomycin caused no ERG change for at least eight weeks after injection. The feature that ERG became non-recordable during one to four weeks after an intravitreal injection of 10mg vancomycin, with recovery of only the c-wave was conspicuous. A dose of 200 micrograms ofloxacin did not cause deterioration of the b-wave, the c-wave or the oscillatory potentials throughout the follow-up period up to eight weeks. Judging from the susceptibility of each ERG component to antimicrobials and taking into account the difference of vitreous volume between rabbits and humans, clinical doses of intravitreal single-shot injection should be less than 1mg for vancomycin and 200 micrograms for ofloxacin.

Animals↗
PubMed1988

Retinal toxicity of antibiotics: evaluation by electroretinogram.

Toxicity of an intravitreal injection of gentamicin sulfate, disodium sulbenicillin and cefazolin sodium on the retina was investigated by electroretinogram in albino and pigmented rabbits. Recordings were made before injection and 2 hours and 3, 7, 14, and 21 days after injection. Significant differences were found in the susceptibility of the electroretinogram components to various antibiotics as follows. Gentamicin 0.24 mg/0.1 ml irreversibly abolished all the components examined. Sulbenicillin 4.0, 8.0, or 12 mg/0.1 ml transiently suppressed the b-wave and the oscillatory potentials incrementally with increasing dose. Cefazolin 0.5, 2.0, or 5.0 mg/0.1 ml selectively reduced the oscillatory potentials, leaving the a- and b-waves almost unattenuated. The cefazolin-suppressed oscillatory potentials recovered within 14 days after injection. Judging from the most susceptible electroretinogram components to each antibiotic, we recommend intravitreal doses of these antibiotics for clinical use as follows: gentamicin 0.1 mg/0.1 ml, sulbenicillin 2 mg/0.1 ml, and cefazolin 0.25 mg/0.1 ml.

Animals↗
PubMed1988

[Anticancer drug screening test for human osteosarcoma transplanted into nude mice].

Osteosarcoma tissue was transplanted into the subcutis of nude mice, and an anticancer drug was injected into the abdomen of the mice. The effects of Cis-platinum, SF-1739HP, Melphalan, Peleomycin and Aclacinomycin were tested. Only Cis-platinum had previously been used in the treatment of osteosarcoma. As the conventional method of evaluation, tumor weight change was recorded along the time course. As a new evaluation method, toluidine-blue was added into the tumor cell suspension prepared from the tumor tissue in the back of nude mice. By the intensity of staining, the tumor cells in suspension were classified into 3 categories; strongly-positive, weakly-positive and negative. Results of evaluation by the staining method were similar to those by measurement of tumor weight. Cis-platinum proved to be most effective, followed in decreasing order by SF-1739HP, Melphalan, Pepleomycin and Aclacinomycin. In conclusion, the staining method is simple and useful for screening the anti-cancer effects of drugs.

Animals↗
PubMed1987

Odontogenic tumor with combined characteristics of adenomatoid odontogenic and calcifying epithelial odontogenic tumors.

A very rare odontogenic epithelial tumor with the combined characteristics of an adenomatoid odontogenic tumor (AOT) and calcifying epithelial odontogenic tumor (CEOT) was found in a 27 year old female. The histopathology, immunohistochemistry of keratin, lectin-binding patterns and distribution of carbonic anhydrase were determined. The nature of the calcified bodies was also examined biophysically. The tumor consisted of cuboidal and columnar odontogenic epithelial cells in the cystic wall, and AOT and CEOT in the central cavity. Odontogenic epithelial cells forming the cyst wall in the CEOT were positive for TK- and KL1-keratins, while that detected with PKK1 antibody was absent in the tumorous epithelium. Lectin binding of tumor epithelial cells was examined with Concanavalin A (Con A), peanut agglutinin (PNA), soybean agglutinin (SBA), dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA), ricinus communis agglutinin (RCA-I), and ulex europeus agglutinin I (UEA-I) lectins, and the tumor epithelium indicated existence of glucose, mannose, Gal, GalNAc, and GlcNAc residues. The lectin binding patterns of the calcified material showed an increased intensity by enzymatic pretreatments. With an electron probe X-ray microanalyser (EPMA), the calcified lesions gave a high peak for calcium ion and for phosphorus ion and a low one for magnesium ion, as obtained from line and surface analysis.

Adult↗