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Biomedical subjects

T Hirasawa

Publications and source records attributed to T Hirasawa.

At least 19 recordsLinked to original sources

The usefulness of ultrasonic microprobe imaging for endoscopic variceal ligation.

OBJECTIVES: This study investigated whether ultrasonic microprobe (UMP) imaging was useful in judging the therapeutic effect of endoscopic variceal (EVL) on varices as well as assessing varices and surrounding vessels before and after EVL. METHODS: UMP imaging was performed repeatedly safely and easily via the biopsy channel of an endoscope in 20 patients with esophageal varices. Using this modality in combination with our method of "intensive ligation," we treated esophageal varices successfully. RESULTS: Before EVL, UMP imaging displayed esophageal varices, periesophageal collaterals, and the azygous vein as echo-free lumens. In 15 of 20 patients, UMP imaging clearly detected the perforating vein, one of the optimal ligation sites for EVL, connecting the varix and collateral vein. Just after EVL, UMP imaging revealed a hyperechoic change ("snow ball" sign or "snow channel" sign), indicating blood flow stasis in the esophageal varices. On subsequent EVL, UMP imaging showed the cross-sectional area of varices was undetectable (occluded) or partially detectaable. After repeated EVL (2.9 treatment sessions on average), UMP imaging, as well as endoscopy, indicated that almost all varices were eradicated (undetectable). However, UMP imaging demonstrated that neither collaterals nor the azygous vein had significantly changed in size. CONCLUSIONS: This modern diagnostic modality provided a clinical adjunct to current endoscopy when observing esophageal varices and surrounding vessels before and after EVL to determine the need for additional therapy.

Aged

[Intermediate filaments].

The antibodies for intermediate filaments, including keratin, vimentin, desmin, GFAP and neurofilaments, have been much useful in routinely-processed immunohistochemical study for identifying characteristics of tumor cells or making the definite diagnosis. In general, when neoplastic transformation has taken place, the affected cells would reveal to some extent alterated immunolocalization of intermediate filaments in the cytoplasm. Whether the tumor cells are of epithelial or non-epithelial origin is significant from diagnostic points of view when utilizing those intermediate filaments as tumor markers. But there are many "exceptional" cases of epithelial tumors with expression of vimentin, or those of non-epithelial tumors with expression of keratin, indicating some "variants". Immunohistochemical application of the intermediate filaments is indispensable not only as "a diagnostic tool for surgical pathologists", but also a method for analyzing relationship between morphological changes and functional aspects of the tumor cells.

Humans

Differentiation of wild- and vaccine-type canine parvoviruses by PCR and restriction-enzyme analysis.

The polymerase-chain reaction (PCR) and restriction-fragment-length-polymorphism (RFLP) analysis were used to differentiate the wild- and vaccine-type of canine parvovirus (CPV) in Japan. The entire coding region of the CPV genome was enzymatically amplified, and the PCR products of three wild strains and four vaccine strains were analysed using RFLP assay. Then, two polymorphic regions in the VP1/VP2 gene were selected to generate strain-specific RFLP patterns. By using four restriction enzymes, wild and vaccine strains were clearly differentiated; only two vaccine strains, probably of the same origin, were indistinguishable from each other. The wild strains retained strain-specific RFLP patterns throughout in vitro passage, and there was no diversity of RFLP patterns among the different lots of vaccine strains. A total of 21 recent field samples were tested, showing RFLP patterns identical to those of a wild strain isolated in 1991. These results suggest that the PCR-RFLP analysis is a practical and reliable method of differentiating wild- and vaccine-type CPVs.

Animals

[The preventive effect of granisetron on digestive tract symptoms induced by arterial infusion of anticancer and hypertensive agents in combination with radiotherapy--a study of forty patients with bladder cancer].

Forty patients with bladder cancer who underwent radiotherapy with angiotensin II, a hypertensor, and two cycles of arterial infusion of anticancer chemotherapies, including cisplatin 100 mg/body, were randomly assigned to a granisetron group and a non-granisetron group for comparative study of its prophylactic effect on nausea, vomiting and anorexia. Granisetron proved significantly effective in preventing nausea, as 75% of granisetron-administered patients experienced either only slight nausea or none at all, against only 22.5% in the non-granisetron group. The number of vomiting episodes was zero during the three-day observation period in 28 out of 40 (70%) granisetron-administered patients compared with 6 patients (15%) in the non-granisetron group. A significant difference in prophylactic effect on anorexia was demonstrated between the granisetron and non-granisetron group, indicating that control of alimentary symptoms such as nausea and vomiting influences the severity of anorexia. As to the safety, nausea was lengthened and deteriorated in one patients. Though the physician in charge judged it to be an adverse event too minor to question the safety of granisetron. Thus, granisetron proved to be highly effective and safe in preventing nausea, vomiting and anorexia in patients under concomitant administration of radiotherapy with hypertensor and arterial infusion of anticancer chemotherapies.

Aged

Phase I study of E1077, a novel parenteral cephem antibiotic.

The safety and pharmacokinetics of E1077, a new injectable cephem antibiotic, were evaluated in healthy male adult volunteers. In the single-dose studies, 100, 250, 500, 1,000, and 2,000 mg of E1077 were administered by intravenous infusion at a constant rate for 60 minutes, then 1,000 mg of the drug by intravenous infusion at a constant rate for 5 minutes. The Cmax were 6.4, 15.7 +/- 12.0, 34.7 +/- 4.6, 63.2 +/- 4.6, 142.7 +/- 5.6, and 131.6 +/- 36.0 (means +/- SD) micrograms/mL, respectively, and the Cmax and AUC increased linearly with the dose. Plasma concentration-time curves were well described by a two-compartment open model. The plasma elimination half life of the drug was 1.88 +/- 0.15 hours. The mean urinary recovery within the first 24 hours was 94.1 +/- 5.1% of the dose. In the multiple-dose study, 2,000 mg of E1077 was intravenously administered at a constant rate over 60 minutes every 12 hours for 4.5 days (a total of nine times). The Cmax after the first and ninth doses were 134.0 +/- 17.4 and 135.5 +/- 15.5 micrograms/mL, respectively, and trough levels in day 1 and day 5 (at 12 hours after the first and ninth administration, respectively) were 2.2 +/- 0.8 and 1.9 +/- 0.4 micrograms/mL, respectively. No accumulation of the drug in plasma was observed. There were no significant differences in plasma levels or in the urinary recoveries between the single- and multiple-dose regimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Serologic and nucleotide sequencing analyses of a novel DR52-associated DRB1 allele with the DR 'NJ25' specificity, designated DRB1*1307.

A novel DR52-associated DRB1* allele, designated DRB1*1307, was encountered in the course of our HLA-DRB1 genotyping study in a Japanese population by PCR-RFLP. Comparison of the nucleotide sequence of its second exon with those of the other known DRB1 alleles revealed that DRB1*1307 was most similar to DRB1*1101, differing by two amino acid substitutions. From a family study, DRB1*1307 was found to segregate with a haplotype of DRB3*0202-DQA1*0501-DQB1*0301, which was also observed with DRB1*1101 in a Japanese population. DRB1*1307 was recognized in three of 652 healthy Japanese controls (gene frequency: 0.24%) with the same DR-DQ haplotype, indicating that DRB1*1307 arose from DRB1*1101 by a gene conversionlike event(s) and/or point mutations. Further, it was also observed that this allele had a strong linkage disequilibrium with HLA-B70 (p < 0.001). This new DRB1*1307 allele was serologically defined as DR 'NJ25,' and it gave an almost identical serologic pattern to DRB1*1406. On sequence comparison, however, no unique amino acid residues conserved in DRB1*1406 and DRB1*1307 but absent in all the other DRB1 alleles could be found, indicating that two amino acid changes at positions 47 and 58 abolished the reactivity against the DR11 antisera.

Alleles

Sensitive detection of canine parvovirus DNA by the nested polymerase chain reaction.

A polymerase chain reaction (PCR) for the detection of canine parvovirus (CPV) was developed. To increase the sensitivity and specificity of the reaction, the nested PCR with a double-nested primer pair (inner primer pair) was designed. The sequences of the PCR primer pairs were selected from the conserved region in the CPV VP1/VP2 gene. The PCR with the outer or inner primer pair alone (single PCR) could detect 10 fg of viral replicative form (RF) DNA on agarose gel electrophoresis; whereas as little as 100 ag of the RF DNA was detected by the nested PCR, which was shown to be 100 times more sensitive than the single PCR. Samples prepared from feline panleukopenia virus and mink enteritis virus, both having a very close antigenic relationship to CPV, were also amplified by the nested PCR. The specificity of the reaction was confirmed by restriction enzyme analysis and Southern hybridization. Next, fecal samples were examined by the nested PCR. All 10 samples suspected of CPV infection were positive, and two restriction sites (HaeIII and HindIII sites) in the PCR product were conserved among them. On the other hand, specific amplification was not observed in the samples derived from normal dogs. The number of the genome copy in positive samples was estimated about 10(9)-10(11)/g by the single PCR and 10(11)-10(13)/g by the nested PCR. The assay can be completed in 1-1.5 days, and does not need radioisotopes. Thus, the nested PCR seems to be a sensitive, specific and practical method for the detection of CPV in fecal samples.

Animals

A genetic linkage map of the mouse using restriction landmark genomic scanning (RLGS).

We have developed a multiplex method of genome analysis, restriction landmark genomic scanning (RLGS) that has been used to construct genetic maps in mice. Restriction landmarks are end-labeled restriction fragments of genomic DNA that are separated by using high resolution, two-dimensional gel electrophoresis identifying as many as two thousand landmark loci in a single gel. Variation for several hundred of these loci has been identified between laboratory strains and between these strains and Mus spretus. The segregation of more than 1100 RLGS loci has been analyzed in recombinant inbred (RI) strains and in two separate interspecific genetic crosses. Genetic maps have been derived that link 1045 RLGS loci to reference loci on all of the autosomes and the X chromosome of the mouse genome. The RLGS method can be applied to genome analysis in many different organisms to identify genomic loci because it uses end-labeling of restriction landmarks rather than probe hybridization. Different combinations of restriction enzymes yield different sets of RLGS loci providing expanded power for genetic mapping.

Animals

Effect of light intensity on polymerization of light-cured composite resins.

The depths of cure and the distributions of degree of conversion (DC), polymerization conversion (PC) and percent pendant double bonds (PDB) of light-cured composite resins cured under various intensities of light were investigated. When the total amount of exposure, represented by the product of the light intensity and the irradiation time, was kept constant, each of the depth of cure and the distributions of DC, PC and PDB were the same for each material regardless of the light intensity and irradiation time. The depth of cure could be expressed as a logarithmic function of the total amount of exposure. From regression analysis, the attenuation coefficient and the critical total amount of exposure capable of initiating polymerization of each composite resin could be determined.

Bisphenol A-Glycidyl Methacrylate

Compressive creep of posterior and anterior composite resins in water.

The compressive creep and the recovery of commercially available composites, 2 kinds for posterior and 2 kinds for anterior use, in water were examined. In posterior composites, creep strain after 500h at a stress level of 8.3 kgf/mm2 was significantly small (within 1%). The results of the compressive creep test showed that posterior composites would be resistant to occlusal stress. Creep strain was higher in anterior composites than that in posterior composites because of their lower inorganic filler content. The rate of recovery of composites was rapid immediately after the creep test. The water sorption of composites after 500h test was almost constant at some reduced stress levels, especially in posterior composites.

Bisphenol A-Glycidyl Methacrylate

Colonization pattern of Pasteurella pneumotropica in mice with latent pasteurellosis.

Colonization pattern of Pasteurella pneumotropica (P. pneumotropica) in mice with latent pasteurellosis was examined with the original selective media, NKBT medium and TGN broth. In the mice of 0 to 15 weeks old, the organism was mainly isolated from the upper respiratory tract, lower intestinal tract, feces and vagina, with the highest isolation rate in the pharyngolarynx. In the pregnant and lactating mice, the organism was isolated from the same sites, but not from the uterus, fetus or mammary gland. In the neonates, the organism was isolated from the respiratory and intestinal tracts within 24hr after birth. The organism was constantly detected in the feces of the 0- to 20-week-old mice, with the highest viable count one week after birth. Through the monitoring of mouse colonies, the pharyngolarynx always showed higher isolation rate than the feces in several mouse strains. These results reveal that the pharyngolarynx is the primary colonization site of P. pneumotropica in mice, and the lower intestinal tract and vagina are also the main sites. Further, frequent isolation of the organism from the feces and vagina, and the results in neonates suggest the mode of the transmission to newborn mice in the colony, i.e., intravaginal infection at the partition, and oro-nasal infection through the maternal feces and saliva.

Animals

The extent of polymerization of Class II light-cured composite resin restorations; effects of incremental placement technique, exposure time and heating for resin inlays.

The extent of polymerization of light-cured composite resins cured in relatively large class II cavities was estimated by measuring Knoop hardness on sectioned surfaces of resin restorations. The influences of the incremental placement technique, exposure time, and post-curing of resin inlay on the extent of polymerization of two different resin materials were examined. For both MFR type (HE) and hybrid type (P50) materials, the 3-step incremental placement technique was superior when the cavity was restored by the direct filling method. For resin inlays, the post-heating improved the conversion of resin restorations. However, because the final degree of conversion of resin attained by heating was influenced by the initial conversion of the resin at the stage of light-curing, the 2-step incremental placement technique was recommended at the light-curing stage for even resin inlays. As the exposure time is influenced by the transmittance of material and the intensity of activator light, it should be optimized in accordance with manufacturers' directions.

Acrylic Resins

Growth of a giant aneurysm following complete thrombosis by detachable balloon occlusion.

A giant basilar artery aneurysm demonstrating growth and causing neurological deterioration even after complete detachable balloon occlusion is reported. Autopsy revealed total thrombosis of the aneurysm and a hemiconcentric, onion skin-like, laminated structure. Numerous vascular channels and multiple fresh intramural hemorrhages were noted within the outer margin of the aneurysmal wall. Repeated intramural hemorrhages appeared to have been responsible for the aneurysmal laminated structure and contributed to progressive aneurysmal growth. This case demonstrates that the growth of some giant aneurysms is not dependent upon the continuity with the parent artery, and progressive enlargement cannot always be prevented by balloon occlusion.

Basilar Artery

[Evaluation of enzyme-linked immunosorbent assay for serodiagnosis of Bordetella bronchiseptica infection in guinea pigs].

An enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of Bordetella bronchiseptica (B. bronchiseptica) infection in guinea pigs was evaluated. An isolate of B. bronchiseptica from lung lesion of a guinea pig was used as antigen after ultrasonication. In the experimental infection, specific pathogen-free guinea pigs inoculated with the bacterium intranasally were examined every 5 or 10 days. The organism was recovered from all animals between 5 and 30 days post-inoculation (p.i.). Only one animal was sero-positive by agglutination test 30 and 50 days p.i.; whereas, by ELISA, one animal was positive 5 days p.i., and all the animals showed strong reaction 20 to 50 (end of experiment) days p.i. Field samples obtained from 1983 to 1989 were tested by ELISA. The results corresponded to those of macroscopic observations and bacterial isolation. The ELISA proved to be useful method for detection of B. bronchiseptica infection in guinea pigs.

Animals

Appearance of collagen fibers in the cerebral vascular wall following subarachnoid hemorrhage.

Ultrastructural examinations of the cerebral vascular wall following subarachnoid hemorrhage (SAH) demonstrated that collagen fibrils developed in the muscle layer near the adventitia in the early stage of SAH and increased in number and volume with time. These findings suggest that accelerating factors of collagen synthesis in the muscle layer may be released from the adventitial side, and collagen synthesis is induced by extravascular factors. The changes of collagen volume with time suggest collagen to be an important phenomenon of persistent vasospasm after SAH. Histoimmunological studies showed that increased collagen fibers in the tunica media were mainly type III collagen, implying that cerebral vasospasm may be related to chemical inflammation.

Animals