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Biomedical subjects

S Yamauchi

Publications and source records attributed to S Yamauchi.

At least 55 records · Page 3Linked to original sources
PubMed1997

Continuous transoesophageal echocardiography monitoring during weaning from cardiopulmonary bypass in children.

The purpose of this study was to evaluate the effectiveness of transoesophageal echocardiography monitoring during weaning from cardiopulmonary bypass after intracardiac repair in children. The left ventricular ejection fraction, left ventricular end-diastolic volume and left ventricle wall motion were monitored continuously by transoesophageal echocardiography in controls weaned easily from cardiopulmonary bypass (group A, n = 25), and those weaned with difficulty from cardiopulmonary bypass after mechanically assisted circulation (group B, n = 16). In group A, left ventricular ejection fraction and left ventricle wall motion were within normal range, and did not change significantly during weaning after cardiopulmonary bypass when compared with pre-bypass data. In contrast, left ventricular ejection fraction, left ventricular end-diastolic volume and left ventricle wall motion in group B during the first trial of weaning from bypass were significantly worsened. Hence, assisted circulation was performed until the data obtained via transoesophageal echocardiography improved with regard to maintenance of fluid balance, catecholamine dosage and assisted pump flow. All cases in group B were weaned safely from cardiopulmonary bypass despite their critical condition. In conclusion, continuous transoesophageal echocardiography monitoring may be a useful tool in children with severe heart failure for safe weaning from cardiopulmonary bypass after intracardiac repair.

Adolescent↗
PubMed1997

Identification, partial characterization, and distribution of versican and link protein in bovine dental pulp.

The dynamics of changes in the cellularity and extracellular matrix composition of dental pulp varies considerably during tooth development and maturation. In this paper, we studied matrix proteoglycans where we hypothesized that they played important roles in structural, spatial, and transport aspects of pulpal development and maintenance. The pulpal tissue was collected from partially erupted bovine incisors, pulverized, and then extracted with 6 M guanidine-HCl. The extract was subjected to anion column chromatography (DEAE-8HR), and the fractions collected were screened by dot-blot immunoassay by means of monoclonal antibodies generated against 4- and 6-sulfated chondroitin sulfate isomers, and keratan sulfate, 2-B-6, 3-B-3, and 5-D-4, respectively. The chondroitin-6-sulfate was the major glycosaminoglycan species and occurred as a large-molecular-weight proteoglycan (> 500 kDa). After further purification, it was subjected to agarose/acrylamide composite gel electrophoresis, and it migrated as a single band stained with Stains-All. The band was immunopositive against antibody 3-B-3 by Western blot analysis. The partial amino acid sequence analyses of the core protein clearly indicated this molecule to be versican. The presence of link protein was also confirmed by Western blot analysis with an anti-link protein monoclonal antibody, 8-A-4. Furthermore, immunohistochemical study indicated that the distributions of versican and link protein coincide in the dental pulp and are enriched in the peripheral area of the tissue just beneath the odontoblast layer. Since the dental pulp contains hyaluronan, versican may bind to hyaluronan via its hyaluronan-binding domain, where this association is stabilized by link protein. This complex, then, could form large hydrated proteoglycan aggregates that fill the extracellular space, support odontoblasts, and/or facilitate the transport function of metabolites and nutrients within the tissue.

Amino Acid Sequence↗
PubMed1997

Serum bone alkaline phosphatase isoenzyme levels in normal children and children with growth hormone (GH) deficiency: a potential marker for bone formation and response to GH therapy.

Serum bone alkaline phosphatase (B-ALP) has been considered to be a good marker for bone formation. Recently, a specific immunoradiometric assay for serum B-ALP has been developed. Using this system, we measured the serum levels of B-ALP in 363 normal children (207 males and 156 females, age 0-18 yr) and in 20 GH-deficient children (age 5-13 yr) who showed significant bone growth during GH therapy. We found the following results. 1) There were no significant circadian variations in serum B-ALP levels (coefficients of variation: 2.10-9.66%). 2) In normal children, serum B-ALP levels were high in infants and gradually declined and increased again during puberty. During the pubertal period, the highest serum B-ALP values were observed at midpuberty (stage 3 of breast and pubic hair development and 4-12 mL of testicular volume). 3) Serum B-ALP levels were significantly correlated with levels of the carboxy-terminal propeptide of type 1 procollagen (r = 0.447, P < 0.0001) and osteocalcin (r = 0.433, P < 0.0001). 4) After beginning GH therapy, serum B-ALP levels increased significantly; a 26% increase in serum B-ALP level was observed after 3 months of GH therapy. 5) The ratio between serum B-ALP level after 3 months of GH therapy and before GH therapy was positively correlated with the GH-induced improvement in the height SD score (height SD score after 1 yr of GH therapy minus that before GH therapy) and improvement in the height velocity SD score (height velocity SD score during GH therapy minus before GH therapy) (r = 0.531, P < 0.05 and r = 0.608, P < 0.01, respectively). 6) The increment of SD score in serum B-ALP level after 1 yr of GH treatment was also significantly correlated with that for bone mineral density after 1 yr of GH therapy (r = 0.663, P < 0.005). These results show that B-ALP levels are a useful marker for bone formation because B-ALP levels increased when the growth rate accelerated. Serum B-ALP is a potential predictor of the effectiveness of GH therapy, because the serum level after 3 months of GH therapy reflects the outcome of 1 yr of GH therapy.

Adolescent↗
PubMed1997

Infective endocarditis. Considerations for the timing of surgical intervention and type of infecting microorganism.

To determine the appropriate timing for surgical intervention in infective endocarditis (IE), we evaluated 24 patients (17 males, 6 females, with one included twice) who underwent surgical intervention for IE of native valves (NVE, n = 21) and prosthetic valves (PVE, n = 3) between January 1989 and September 1994. The mean age was 41 +/- 13 years (range 6 to 64 years). The most common infective organisms were Staphylococcus (33% of NVE) and Streptococcus (19% of NVE), with five NVE patients (24%) negative for blood culture. The PVE patients showed a different pattern of infecting organisms, with Enterococcus in one and Pseudomonas in another. From the resected valve culture and pathological findings, 12 patients were in the active stage at operation. Two in-hospital deaths occurred for a mortality rate of 8.7% (2/23). Further, surgical interventions were performed earlier with Staphylococcal infections than with Streptococcal infections, because hemodynamic compromise presented more progressively in the former. Also resected valve cultures and the pathological findings showed that a persistent infectious process existed in many cases of Staphylococcal infection in spite of intensive antibiotic therapy. In conclusion, we suggest that internists make referrals for surgical intervention for patients with NVE or PVE as early as possible in the active stage of infection.

Adolescent↗
PubMed1997

Production of the immunosuppressive cytokine interleukin-10 by Epstein-Barr-virus-expressing pyothorax-associated lymphoma: possible role in the development of overt lymphoma in immunocompetent hosts.

Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. Thus, the term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most PALs are diffuse lymphomas of B cell type and contain Epstein-Barr virus (EBV) DNA. We have established two lymphoma cell lines from the biopsy specimens of PAL cases, OPL-1 and OPL-2. Both cell lines contain EBV DNA, but only OPL-1 expresses EBV nuclear antigen 2, which works as a target molecule for the cell-mediated immune response. As systemic immunodeficiency is unlikely to be present in PAL patients, PAL from which OPL-1 derived was not expected to be fully developed. In this study, we examined the expression of immunosuppressive factors in OPLs. Only OPL-1, not OPL-2, expressed interleukin-10 (IL-10) mRNA and secreted IL-10 into culture supernatant. Both OPL-1 and OPL-2 expressed transforming growth factor (TGF)-beta 1 mRNA; however, neither expressed latent TGF-beta-binding protein mRNA at a detectable level by Northern blot analysis. Because TGF-beta expresses its functions in cooperation with latent TGF-beta-binding protein, the biological functions of TGF-beta 1 could be negligible. Neither cell line expressed at a detectable level EBV BCRF-1 mRNA, a viral gene product that is partly homologous to human IL-10 and shares biological activities of IL-10. Although IL-10 is reported to promote the growth of activated or neoplastic B cells, OPL-1 did not respond to human recombinant IL-10 by growing faster. As OPL-1 expresses a target antigen for the host cytotoxic T-cell response, the production of an immuno-suppressive cytokine, IL-10, might contribute to the development of overt lymphoma by inducing locally immunosuppressive circumstances. The present study suggests that an immunosuppressive cytokine plays a role in lymphomagenesis of immunocompetent patients.

Animals↗
PubMed1997

Pirfenidone prevents collagen accumulation in the remnant kidney in rats with partial nephrectomy.

Pirfenidone (PFD) is a new compound that prevents and even reverses the extracellular matrix accumulation in several organs as shown by experimental and clinical studies. In the present study, we examined the effect of PFD (500 mg/kg daily in the food) on the progression of chronic renal failure (CRF) in the 5/6 nephrectomy rat model. Proteinuria progressively increased in rats with renal ablation (C) at 12 weeks. Urinary protein excretion in PFD-treated rats (P) was numerically lower than C, but the difference did not reach statistical significance. In contrast, in the chronic phase, PFD improved renal function and reduced collagen accumulation detected by hydroxyproline content (OH-Pro) in the cortex of the remnant kidney. Although creatinine clearance decreased with time in C, the values in P were significantly better at 10 and 12 weeks. The OH-Pro in C at 12 weeks was significantly higher than that of no-ablation, sham-operated rats, whereas OH-Pro in CRF was lower in (P). Expression of mRNA for type IV and I collagen in the cortex also increased in C, but it was inhibited in (P). To study the role that TGF-beta plays in the regulatory process following CRF, we examined the expression of TGF-beta mRNA in this model. Levels of cortical TGF-beta mRNA in C were significantly elevated at 12 weeks. The increase was suppressed by PFD. These results demonstrate that PFD attenuates the development of CRF by preventing collagen accumulation in this model, and suggest that PFD can be clinically useful for treating CRF.

Animals↗
PubMed1996

Development of protamine-bonded phase for separation of saccharides in liquid chromatography.

A protamine-bonded polymer gel was synthesized by passing this protein through an activated carbamate polyamine polymer gel layer. This new packing material was suitable for versatile separation of monosaccharides, oligosaccharides, sugar alcohols and uronic acids in liquid chromatography. The column packed with this gel could be operated at room temperature and gave excellent recovery for the reducing monosaccharides such as 2-deoxyribose, 2-deoxyglucose, ribose and mannose for which the conventional alkylamine-bonded phase column gave poor recovery. This column was used for the analysis of saccharides in urine using a post-column reaction detection system.

Amino Acid Sequence↗
PubMed1996

Atrial activation during chronic atrial fibrillation in patients with isolated mitral valve disease.

BACKGROUND: A computerized 32-channel mapping system has been developed to investigate the characteristics of the atrial activation sequence. The system is capable of displaying sequential atrial maps and provides a rapid and dynamic means of verifying the activation sequence of atrial fibrillation. METHODS: Using this system, we performed intraoperative atrial activation mapping in 10 patients with chronic atrial fibrillation who were undergoing isolated mitral valve operations. RESULTS: Regular and repetitive activation (cycle length ranged from 131 to 228 milliseconds) originated in the left atrium in all 10 patients. Two patterns of repetitive activation in 2 patients and three patterns in 1 patient appeared alternately during the observation period in the left atrium. In contrast to the repetitive activation in the left atrium, the activation sequence of the right atrium was extremely complex and chaotic. In 7 of the 10 patients, the same pattern of right atrial activation was never repeated during the observation period. In 2 patients, revolution of repetitive activation in the right atrium sporadically appeared, but the pattern of activation immediately deteriorated to a complex and chaotic pattern. In 1 patient, repetitive activation emerged from the low lateral portion of the right atrium. Because our mapping technique was limited by the number of available atrial electrodes, discrete reentrant circuits or ectopic foci could not be demonstrated in the present study. However, the activation sequences during chronic atrial fibrillation suggested that (1) the left atrium would act as an electrical driving chamber for atrial fibrillation in the majority of the patients and (2) atrial activation patterns are different in each case. CONCLUSIONS: Computerized intraoperative mapping should guide surgeons in determining the appropriate surgical procedure and facilitate operation for chronic atrial fibrillation associated with mitral valve disease.

Adult↗
PubMed1996

Aortic dissection extending from the left coronary artery during percutaneous coronary angioplasty.

A 72-year-old woman with acute aortic dissection as a complication of percutaneous coronary angioplasty was successfully treated. She received a graft replacement of the ascending aorta as well as triple coronary artery bypass grafts. The dissection had extended from the left coronary artery. Although acute aortic dissection is a rare complication of percutaneous coronary angioplasty, physicians and cardiac surgeons should keep its potential occurrence in mind.

Acute Disease↗
PubMed1996

Immunological and virological study of sudden deafness.

Thirty-three patients with sudden deafness and 11 controls were selected from the patients admitted to the Department of Otolaryngology, Tokai University Hospital from November 1990 to October 1991. Viral titers were measured for mumps, adenovirus, rubella, measles, herpes simplex virus (HSV), varicella zoster virus (VZV), rhinosyncytial virus, cytomegalo-virus (CMV), and mycoplasma pneumoniae in 33 sudden deafness patients and 11 controls at a 2-week interval. In 20 of 33 sudden deafness patients and 5 of 11 controls, autoantibodies of rheumatoid factor (RF), anti-mitochondrial antibody (AMA), anti-nuclear antibody (ANA), anti-parietal cell antibody (APA), anti-smooth muscle antibody (ASA), and anti-type II collagen antibody were studied. Viral titer study did not reveal any significant change either in the patients or in the controls, whereas autoantibody study revealed a relatively high incidence for ASA in the patients as compared with the controls. The relatively high incidence for ASA suggests that immune-mediated processes may be involved in the etiology of sudden deafness.

Adenoviridae↗
PubMed1996

A rapid serological detection method for squamous cell carcinoma.

OBJECTIVE: We conjugated the squamous cell carcinoma (CA)-associated antibody (anti-YM antibody) with gelatin particles. We found that these particles reacted specifically with the tumor-associated antigen (YM antigen) in serum samples from patients with squamous cell CA of the uterine cervix and various organs (GPA reaction). METHODS: 1) We performed immunohistochemical studies of the YM antigen in dysplasia and invasive squamous cell CA of the uterine cervix; 2) We measured the GPA reaction in various malignant and non-malignant gynecologic diseases. RESULTS: 1) Immunohistochemical localization of the YM antigen was over 75% in cases of dysplasia and invasive squamous cell CA of the uterine cervix, and was 21% in normal squamous epithelium of the uterine cervix. 2) The GPA reaction in gynecologic diseases was positive in 57.1% of the dysplasia cases; in CIS cases, 69.2%; in cervical CA, 83.0%; in corpus CA, 25.0%; in leiomyoma 16.7%; and in pregnant serum samples, 66.7%, 3) GPA reactions in non-ob-gyn cases were positive in 68.8% of the cases of squamous cell CA of the head and neck; 66.7% in cases of squamous cell CA of the lung; and 25.0% in adenoCA of the lungs whereas the sera of patients with benign tumors and of healthy persons were free of the YM antigen. CONCLUSION: We concluded that this newly developed GPA-reaction measurement is a simple and reliable serologic test for detecting the initial stage of squamous cell CA of various organs and for monitoring its postoperative status.

Agglutination Tests↗
PubMed1996

A case report of simultaneous surgery for Wolff-Parkinson-White syndrome combined with hemolytic anemia and mitral stenosis.

A 46-year-old woman with mitral stenosis, WPW syndrome, hemolytic anemia due to spherocytosis, and hypothyroidism with Hashimoto's thyroiditis, was admitted with palpitations and dyspnea due to paroxysmal atrial fibrillation with a rapid ventricular response, and was treated by electrical cardioversion. We selected surgical intervention to treat the mitral stenosis and WPW syndrome, as some tachycardia episodes due to atrial fibrillation have resulted in repeated congestive heart failure. In 1983 we simultaneously performed a division of the posteroseptal accessory pathway and a mitral valve replacement with a bioprosthetic valve under cardiopulmonary bypass, using a membrane oxygenator after splenectomy to compensate for the hemolytic anemia due to spherocytosis. Her postoperative course was favorable and she is now in good health with no episodes of tachycardia, congestive heart failure nor anemia occurring during the 10 years that have followed the operation. Simultaneous surgery for WPW syndrome combined with other cardiac abnormalities and hematologic disorders achieved acceptable results in this case.

Anemia, Hemolytic↗
PubMed1996

Interleukin-6-mediated growth enhancement of cell lines derived from pyothorax-associated lymphoma.

Malignant lymphomas frequently develop in the pleural cavity of the patients with long-standing pyothorax. Thus, the term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most PAL are diffuse large cell lymphoma of B cell type that contain Epstein-Barr virus DNA. We have established two lymphoma cell lines from the biopsy specimens of PAL cases, OPL-1 and OPL-2. Because PAL develop in the sites of chronic inflammation, inflammatory cytokines might be involved in the lymphomagenesis. To address this point, we examined the regulation of the growth of OPL by human IL-6. Human recombinant IL-6 enhanced the growth rate of OPL. OPL-1 responded to recombinant IL-6 by growing faster even at concentrations of less than 0.1 ng/ml, whereas OPL-2 required higher concentrations of recombinant IL-6. OPL expressed IL-6 receptor mRNA detectable by reverse transcriptase PCR analysis and IL-6 receptor on cell surface by flow cytometric analysis, using anti-IL-6 receptor antibodies. On the other hand, only OPL-1 showed expression of IL-6 mRNA, which was detectable only by reverse transcriptase PCR, and secreted IL-6 protein into the culture media. The culture supernatant of OPL-1 exhibited growth-enhancing effects on OPL-1 and OPL-2. The addition of anti-IL-6 antibodies to the cultures inhibited the growth of OPL-1 but not OPL-2. OPL-2 did not secrete IL-6 protein into the media, and the culture supernatant from OPL-2 did not enhance growth of OPL-2. These findings suggest the involvement of IL-6 in the growth regulation of OPL, i.e., an autocrine mechanism of IL-6-related proliferation in OPL-1 and a paracrine mechanism in OPL-2. IL-6 locally produced in chronic pyothorax might also promote the development of PAL.

Base Sequence↗
PubMed1995

Coexistence of Pick bodies and atypical Lewy bodies in the locus ceruleus neurons of Pick's disease.

We observed abundant Pick argentophilic inclusion bodies (PBs) as well as some atypical Lewy bodies (LBs) in the locus ceruleus (LC) from a patient with Pick's disease. In addition, there were a few neurons which contained both PBs and LBs. PBs in the LC frequently appeared multiple and had lobulated or irregular shapes, though their ultrastructural elements were the same as those of the PBs appearing in the cerebral cortex, and consisted of randomly arranged smooth-surfaced straight tubules of 15 nm in diameter, mixed with a small number of long-period constricted fibrils. The ultrastructure of the LB coexisting with PB was identical with that previously reported; a dense core was surrounded by concentric layers of radially oriented 10-nm filaments and was clearly distinguishable from the PB. Immunohistochemical examination with various antibodies related to neurofibrillar pathology demonstrated that anti-tau antibodies reacted positively with both PB and the rim portion of LB in the present case; an unusual finding for LB. The anti-neurofilament 200-kDa protein stained only LBs, even when PBs and LBs coexisted in the same neuron. These findings show that two kinds of neuronal fibrillar inclusions, whose underlying cytoskeletal abnormalities are thought to be different, can coexist in the same neuron. In addition, the formation of multiple, lobulated PBs may suggest some particularity of cytoskeletal composition of the LC neurons.

Aged↗
PubMed1995

Preventive effect of pirfenidone against experimental sclerosing peritonitis in rats.

We investigated the preventive effect of pirfenidone (PFD), a newly developed anti-fibrotic agent, on experimental sclerosing peritonitis (sp) which we had established in rats. Male Wistar rats (150-250 g) were divided into the following two groups; 7 rats were treated with daily intraperitoneal (i.p.) injection of 0.1% chlorhexidine gluconate (CH) and 15% ethanol solved in 2 ml of saline for 26 days as a control of SP model (CH group) and 6 rats were treated daily with peroral (p.o.) administration of 350 mg/kg of PFD in addition to the daily i.p. injection of aforementioned CH-ethanol-saline solution for 26 days (CH + PFD group). Macroscopic intraperitoneal changes and histological fibrotic changes were graded by scoring in a blind manner. Actual subserosal thickness was measured by observation under light microscope. Body weight gain was significantly greater in CH + PFD group than in CH group (P < 0.05). Macroscopic intraperitoneal adhesion changes in CH + PFD group were significantly fewer than in CH group (P < 0.05). Fibrotic changes were fewer and subserosal thickness in liver and intestine were smaller in CH + PFD group with statistical significance (p < 0.1). We concluded that PFD markedly inhibited or prevented fibrotic changes in the experimental sclerosing peritonitis induced by CH.

Animals↗
PubMed1995

Nd:YAG laser irradiation in root canal disinfection.

The purpose of this study was to assess the efficacy of Nd:YAG laser irradiation in disinfecting the root canal system. Seventy-five teeth were uniformly instrumented and sterilized, and their root canals were infected for 60 min with an overnight culture of Enterococcus faecalis in Tryptic Soy Broth. The teeth were divided into 6 groups: 1--non-infected controls; 2--infected controls; 3--infected, laser treated; 4--infected, laser dummy (dye only); 5--infected, laser dummy (dye and air-water spray); 6--infected, NaOCl-treated (reference group). After treatment, the root canals were dried and dentinal shavings removed for a post-treatment culture. Quantitative analysis of bacteria surviving the various treatments were performed and the bacterial counts for each group were compared. SEM analysis of teeth split longitudinally was used to illustrate the effect of treatment on the smear layer and on surface bacteria. Nd:YAG laser irradiation (group 3) significantly reduced the number of bacteria while NaOCl irrigation (group 6) effectively disinfected the canals.

Aniline Compounds↗
PubMed1995

[Measurement of anti-acetylcholine receptor antibody using human rhabdomyosarcoma cell line].

We developed a radioimmunoassay for AChR Ab using AChR solubilized from membrane extracts of human rhabdomyosarcoma cell line (RD cell). The binding affinity of this AChR to the alpha-Bungarotoxin (alpha-BTX) was similar to that of AChR from cell surface. Lyophilized AChR was stable within two months at -20 degrees C. In our assay system, sera from patients with Myasthenia Gravis (MG) showed markedly high titers and frequency (94%) of anti-AChR Ab. On the other hand, almost all sera from normal and non-myasthenic patients such as rheumatoid arthritis and thyroid disease were negative (< 0.2nmol/l). Our assay using AChR from RD cells shows sufficient results in the intra- and inter-CV values, and recovery and dilution tests. AChR Ab titers of our assay showed good correlations with those measured by AChRs from both human ischemic muscles and TE671 cells (commercial kit). The radioimmunoassay for AChR Ab using the membrane extracts of RD cells has high sensitivity, specificity and stability. Therefore, the assay is valuable as the routine assay for the diagnosis of MG.

Autoantibodies↗