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Biomedical subjects

S Yoshii

Publications and source records attributed to S Yoshii.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Effects of preserving mitral apparatus on left ventricular systolic function and geometry in mitral valve replacement].

We investigated the left ventricular (LV) systolic function and geometry in mitral valve replacement (MVR) with and without preservation of mitral apparatus. Five patients had conventional MVR without mitral annulus papillary muscle continuity (group C) and five patients had MVR with preservation of the continuity (group P). LV cineangiograms were assessed before and one month after surgery. LV volume was calculated by the method of Kennedy. Long axis dimension is defined as the distance between the apex and the center of mitral orifice in right anterior oblique projection. Short axis dimension is defined as the cross-sectional dimension at the middle point of the long axis. Paired Student's t tests were employed to compare the preoperative and postoperative data. LV ejection fraction decreased significantly from 69.4 +/- 9.5 to 51.8 +/- 10.5% in group C (p < 0.05) and did not change significantly in group P (from 51.6 +/- 19.9 to 56.8 +/- 12.9%). Fractional shortening of the long axis increased significantly from 15.0 +/- 11.8 to 21.2 +/- 14.0% in group P (p < 0.02) and did not change significantly in group C (from 16.5 +/- 8.6 to 13.1 +/- 3.3%). Ratio of LV end-systolic long axis to short axis dimension increased significantly from 1.76 +/- 0.31 to 2.12 +/- 0.21 in group C (p < 0.05) and did not change significantly in group P (from 1.90 +/- 0.22 to 1.95 +/- 0.22). We conclude that the ratio of systolic long to short axis increases, i.e., systolic LV shape changes to become longer and slender, and ejection fraction decreases after surgery in MVR without preservation of mitral apparatus. Conversely, preserving the mitral apparatus in MVR results in no significant change in systolic LV function and geometry, because of preserving fractional shortening of long axis.

Aged↗
PubMed1994

Transesophageal echo-guided balloon dilatation for postoperative pulmonary venous obstruction.

Pulmonary venous obstruction (PVO), or stenosis, is still a major complication of postoperative total anomalous pulmonary venous return, being very complex in its pathogenesis. For some types of PVO, surgery is effective, but a reoperation under cardiopulmonary bypass is generally difficult and carries a high risk. The operative balloon dilatation method performed under the guidance of transesophageal echography and fluoroscopic monitering is simple as well as safe. We describe herein the technique involved in performing this procedure through the case of a 10-month-old boy.

Catheterization↗
PubMed1994

Isolation and classification of temperature-sensitive mutants of influenza B virus.

We isolated 25 temperature-sensitive mutants of B/Kanagawa/73 strain generated by mutagenesis with 5-fluorouracil and classified them into seven recombination groups by pair-wise crosses. All mutants showed a ratio of plaquing efficiency at the nonpermissive temperature (37.5 C) to the permissive temperature (32 C) of 10(-4) or less. At 37.5 C most of group I, II, and III mutants did not produce appreciable amounts of protein, but all other group mutants were protein synthesis-positive. A group VII mutant produced active hemagglutinin (HA) and neuraminidase (NA) at the nonpermissive temperature, but Group V mutants produced only active NA and were defective in the HA molecule. The other group mutants, including group IV mutants with mutation only in the NA gene (8, 10), lacked both activities at the nonpermissive temperature. One of nine influenza B virus isolates in 1989 had EOP 37.5/32 of 1/3 x 10(-2) and belonged to recombination group VII.

Animals↗
PubMed1994

Role of neuraminidase in the morphogenesis of influenza B virus.

When ts7, a temperature-sensitive (ts) mutant of influenza B/Kanagawa/73 virus, infected MDCK cells at the nonpermissive temperature (37.5 degrees C), infectious virus was produced at very low levels compared with the yield at the permissive temperature (32 degrees C) and hemagglutinating activity and enzymatic activity of neuraminidase (NA) were negligible. However, viral protein synthesis and transport of hemadsorption-active hemagglutinin to the cell surface were not affected. When the cell lysate was treated with bacterial NA, hemagglutinating activity was recovered but infectivity was not, even after further treatment with trypsin. It was found that ts7 was defective in transport of NA to the cell surface and formation of virus particles. Analysis of the genomes of non-ts recombinants obtained by crossing ts7 and UV-inactivated B/Lee showed that ts7 had the ts mutation only in RNA segment 6 coding for NA and the glycoprotein NB. Nucleotide sequence analysis of the RNA segment revealed that ts7 had four amino acid changes in the NA molecule but not in NB. We suggest that assembly or budding of influenza B virus requires the presence of NA at the plasma membrane, unlike influenza A virus.

Amino Acid Sequence↗
PubMed1994

[Intrabronchial neurilemmoma: a case report].

A 62-year-old woman who was pointed out abnormal shadow at left middle lung field in chest X-ray was followed up as a hamartoma from 1989. In this period, the tumor was growing up in chest X-ray and occupying the left segmental bronchus (B3) in bronchofiberscopic study. It was suspected neurilemmoma by the final biopsy examination. Left upper lobectomy was performed and pathohistological diagnosis was typical neurilemmoma that consist of Antoni type A and Antoni type B. Intrapulmonary or intrabronchial neurilemmoma is rare and only 20 cases have been reported in the Japanese literature.

Bronchial Neoplasms↗
PubMed1993

Biloma during steroid therapy for minimal change nephrotic syndrome.

A 27-year-old man, who had been on steroid therapy for 2 months for his nephrotic syndrome, suddenly developed intra-abdominal bile collection (biloma). He had no previous history of abdominal surgery, trauma, or any disease of the hepatobiliary system. The cause of the biloma formation was due, probably, to cholecystitis in the absence of calculi and a pinhole size perforation in the wall of gall bladder. It was assumed to be closely related to the high-dose steroid therapy over a prolonged period, which would likely suppress the repair process of the locally damaged biliary system.

Abdominal Pain↗
PubMed1993

[Usefulness of Vmax and time constant in the evaluation of left ventricular function immediately after cardiac operation].

It is difficult to evaluate the cardiac function accurately, immediately after cardiac operation, because of the restriction of measurements and the variations of loading. To evaluate the exact cardiac function during and after cardiac surgery, we examined the usefulness of unloaded maximal shortening velocity of contractile element (Vmax) and time constant of isovolumic pressure fall (TC) in the condition of hasty changing of preload and afterload. In our experiment, we used canines as our subject. Following the sedation of the canines, the left ventricular pressure (LVP) curve was recorded by using the catheter-tip manometer which was introduced into the apex of the heart. The LVP was measured in the following instances: 1) at control condition, 2) 5 minutes after the administration of dobutamine of 2 or 5 micrograms/kg/min, 3) 5, 10, 15, and 30 minutes interval after the ligation of the left anterior descending artery (LAD). In every situations, preload and afterload were changed by the temporary occlusion of the inferior vena cava or descending thoracic aorta. Vmax and TC were analyzed easily only from the LVP by the personal computer. We used Grunkemeier's method to calculate Vmax which was analyzed only from the LVP curve. We presumed that the mean value of Vmax analyzed by Grunkemeier's method was almost the same as the data by Mason's method by calculating the mean value from the given number of heart beats. Because the correlation of two methods was linear, and furthermore the slope of this regression line was 0.97 and the Y-intercept was 0.19. Vmax was the index that was comparatively independent from the loading condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Computerized recording system during cardiopulmonary bypass utilizing the "GEM 6 PLUS analyzer"].

We developed a new computerized recording system to reduce artificial errors by perfusionists during cardiopulmonary bypass. This system included the efficient functions to record the progress of perfusion flow, perfusion pressure, urine output and temperatures from several sources. Furthermore, it could automatically record considerable data of the "GEM 6 PLUS analyzer" which was developed for monitoring of pH, PCO2, PO2, BE, Ca2+, K+ and hematocrit during cardiopulmonary bypass. We considered it very important that the errors of hematocrits associated with electrolytic concentrations. Therefore, we corrected the hematocrit according to a formula based on our experiments, i.e., HCT = GEMHCT + 0.28 x ([Na+]+[K+]) -44. And also we expect that the "GEM 6 PLUS analyzer" will be improved to measure Na+ value in near future.

Body Temperature↗
PubMed1992

Glass-ceramic implant in acetabular bone defect: an experimental study.

Extensive acetabular defects produced surgically in 25 dogs were repaired using A-W glass-ceramic blocks. No dislocation of the femoral head, and no displacement or breakdown of the blocks was seen 1 year after surgery. All dogs were able to run normally shortly after surgery, except for one that limped for a short time. The failure load between the blocks and the bone had increased markedly 2 months after implantation. The failure load/unit area was 33.2 kgw/cm 2 1 year after implantation. We conclude that glass-ceramic supplementation of the acetabulum is successful experimentally, and that this may be a promising method for repair of large acetabular bone defects.

Acetabulum↗
PubMed1992

Influence of substituting B2O3 for CaF2 on the bonding behaviour to bone of glass-ceramics containing apatite and wollastonite.

Glass-ceramics containing crystalline oxy-fluoroapatite (Ca10(PO4)6(O,F2)) and wollastonite (CaSiO3) (designated AWGC) are reported to have a fairly high mechanical strength as well as the capability of forming a chemical bond with bone tissue. The chemical composition is MgO 4.6, CaO 44.9, SiO2 34.2, P2O5 16.3, and CaF2 0.5 in weight ratio. In this study the influence of substituting B2O3 for CaF2 on the bonding behaviour of glass-ceramics containing apatite and wollastonite to bone tissue was investigated. Two kinds of glass-ceramics containing apatite and wollastonite were prepared. CaF2 0.5 was replaced with B2O3 at 0.5 and 2.0 in weight ratio (designated AWGC-0.5B and AWGC-2.0B). Rectangular ceramic plates (15 x 10 x 2 mm, abraded with No. 2000 alumina powder) were implanted into a rabbit tibia. The failure load, when an implant detached from the bone, or the bone itself broke, was measured. The failure load of AWGC-0.5B was 8.00 +/- 1.82 kg at 10 weeks after implantation and 8.16 +/- 1.36 kg at 25 weeks after implantation. The failure load of AWGC-2B was 8.08 +/- 1.70 kg at 10 weeks after implantation and 9.92 +/- 2.46 kg at 25 weeks after implantation. None of the loads for the two kinds of glass-ceramics decreased as time passed. Giemsa surface staining and contact microradiography revealed direct bonding between glass-ceramics and bone. SEM-EPMA showed a calcium-phosphorus rich layer (reaction zone) at the interface of ceramics and bone tissue. The thickness of the reaction zone was 10 to -15 microns and did not increase as time passed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The hormonal response to HCG stimulation in patients with male infertility before and after treatment with hochuekkito.

To investigate the changes in responsiveness to hCG stimulation, and the effects on sperm qualities and basal hormone levels, 63 infertile men received 7.5qr of Hochuekkito daily for 3 months (1). Sperm density (p less than 0.01) and motility (p less than 0.01) were significantly increased after the treatment (2). Serum prolactin (p less than 0.01) and estradiol (p less than 0.01) levels were significantly decreased after the treatment (3). Enhanced responsiveness of testosterone (p less than 0.05) and estradiol (p less than 0.05) excretion to hCG injection were observed in patients with oligoasthenoteratozoospermia. These results suggested that Hochuekkito corrected Leydig cell dysfunctions in some infertile men, resulting in improvements in sperm qualities.

Adult↗
PubMed1992

[Clinical experience of local thermotherapy in the treatment of benign prostatic hyperplasia].

Thirty-five patients with benign prostatic hyperplasia (age range: 45-88 years; average: 67.5 years) underwent local thermotherapy with prostathermer. Clinical therapeutic effect was evaluated in 30 of the 35 patients: 2 patients interrupting from therapy and 3 receiving pretherapeutic indwelling catheters were not included. A total of 6 treatments (2 per week) were performed, each lasting for 60 minutes. As for subjective improvement, improvement of nocturia was noted in 70.0% of all patients and sense of residual urine in 70.7%. Post-therapeutic nocturnal and daytime decreases in urination frequency were statistically significant (p less than 0.01). Objective improvement in residual urine volume occurred in 19 of the 30 cases, and elevation in uroflowmetric maximal flow rate following therapy was statistically significant (p less than 0.05). Among complications ascribable to catheter insertion were urethral bleeding (3 cases), epididymitis (1 case) and pyuria (1 case). Therapeutic result based primarily on subjective symptoms and partly on objective findings was fairly good in 17 cases (about 57%), and slightly good in 25 cases (about 83%). In conclusion, this therapy seems to be useful in the treatment of benign prostatic hyperplasia.

Aged↗
PubMed1992

[Chest wall reconstruction with a prosthetic material molded from a extirpated specimen].

A new molding technique of the Acryl-resin Marlex-mesh sandwich method is described. After the wide extirpation of the chest wall, the defect size tends to grow up more larger than the specimen. For making a just fit size prosthesis, we cut off a cardboard as the same size as the specimen and the Acryl-resin Marlex sandwich is molded from the cardboard. Other some know-how are in the text.

Acrylic Resins↗
PubMed1991

Biodegradable screw fixation of rabbit tibia proximal osteotomies.

The purpose of this study was to evaluate a biodegradable poly(L-lactide) (P-L-LA) screw for osteosynthesis under a load-bearing condition. A proximal tibial osteotomy on 25 rabbits was fixed with a biodegradable screw made of P-L-LA. A follow-up study was done at 1, 2, 4, 8, and 16 weeks. In another 25 rabbits, the tibial osteotomy was fixed with stainless steel (SUS) screws of the same size as the P-L-LA screws with a similar follow-up period. Radiographic, histological, microradiographic, and oxytetracycline-labeling studies showed healing of the osteotomy within 4 to 8 weeks. The displacement of fragments and the mass of newly formed bone around the screws were measured by histomorphometric analysis. There was no significant difference in the displacement of the fragments in these two groups and new bone was more abundantly detected in the P-L-LA group than in the SUS group. Histologically, no inflammatory lesion was detected in either group. All osteotomies united without delay and the displacement was minimal, although no external support was applied and the rabbits were allowed to move freely after the operation. The results of this study suggest a possible use for a P-L-LA screw in the clinical treatment of human bone fractures.

Animals↗