Biomedical subjects

H Yamauchi

Publications and source records attributed to H Yamauchi.

At least 145 records · Page 8Linked to original sources

PubMed1998

Effects of dynamic cardiomyoplasty on left ventricular systolic and diastolic performance in an acute canine model.

Although dynamic cardiomyoplasty (DCMP) is currently being evaluated as an alternative to end-stage congestive heart failure, the overall results of DCMP are variable and inconclusive. We evaluated the effect of classic DCMP on systolic and diastolic cardiac function in normal heart using reliable indicators which minimize the influences of load conditions. Six experimental dogs were evaluated with the acute nonpreconditioning model. The slope of the linear preload recruitable stroke work relationship (Mw) showed a significant increase with latissimus dorsi muscle (LDM) stimulation (postwrap non-stimulation 59.1+/-6.3, postwrap stimulation 98.6+/-9.7 erg cm(-3) x 10(3); P < 0.01), and the x-intercept (V0) was unchanged; these were utilized as the indicators of left ventricular systolic function. The constant of pressure decay (tau) increased after LDM wrap (prewrap 45.8+/-6.0, postwrap nonstimulation 69.3+/-10.3, postwrap stimulation 72.3+/-13.9 ms; P < 0.05), and the peak filling rate was unchanged after LDM wrap, which were utilized as the indicators of diastolic function. We concluded that classic dynamic cardiomyoplasty is effective in assisting systolic cardiac function, but may to some degree have a detrimental effect on the diastolic cardiac function.

Animals↗

PubMed1998

Establishment of a human fibroblast cell line producing tumor necrosis factor alpha (KMST-6/TNF) and growth inhibitory effects of its conditioned medium on malignant cells in culture.

To develop a new gene therapy model for cancer, a clonal cell line (KMST-6/TNF) which produces human tumor necrosis factor alpha (hTNF-alpha) has been developed by introducing hTNF-alpha cDNA into a human immortal fibroblast cell line (KMST-6). The conditioned medium (CM) of KMST-6/TNF cells inhibited the growth of various malignant human cell lines, but not that of normal human fibroblasts. Although the growth inhibitory effects of KMST-6/TNF CM were neutralized to a considerable degree by anti-TNF-alpha antibody, its inhibitory effects were more marked than the purified human natural TNF-alpha itself in the same units, suggesting that KMST-6/TNF CM contains some growth inhibitory substances other than TNF-alpha. However, interferons alpha, beta, and gamma were undetectable in the KMST-6/TNF CM.

Blotting, Northern↗

PubMed1998

Circulating tumor markers in breast cancer: accepted utilities and novel prospects.

Detecting and/or monitoring changes in circulating tumor markers might assist in evaluating cancer risk, diagnosis, prognosis, or response to treatment. Several categories of circulating tumor markers have been investigated in breast cancer. These categories include classical tumor-associated antigens, such as CEA and CA 15-3, markers of tumor biology, including markers of angiogenesis, adhesion, and invasion, and antibody response to tumor-associated antigens such as HER2/neu and p53. We used a recently proposed Tumor Marker Utility Grading System to evaluate the use of several circulating tumor markers for different clinical utilities in breast cancer. While there are no tumor markers with established clinical utilities for most uses, tumor-associated antigens can be used for monitoring patients with metastatic disease. In addition, markers of tumor biology such as the circulating extracellular domain of HER2/neu might be useful in determining not only prognosis, but also response to specific treatments. However, further investigations are required to further assess the utility of individual tumor markers for specific clinical uses.

Biomarkers, Tumor↗

PubMed1998

Cloning and expression of a single-chain Fv fragment specific for the human interleukin 18 receptor.

We have recently reported the successful purification and characterization of the human interleukin 18 (IL-18) receptor (R) using a monoclonal antibody (MAb) of the IgM kappa class (117-10C) after immunizing mice with cells of the Hodgkin's disease-derived cell line L428. This antibody is specific for the human IL-18R and inhibits the bioactivity of IL-18. Here we report on the polymerase chain reaction (PCR)-assisted cloning and sequencing of cDNAs encoding the variable regions of the light and heavy chains of 117-10C. We expressed the antibody in the form of a single-chain Fv fragment (scFv) in Chinese Hamster Ovary (CHO) cells and purified it from culture supernatants by chromatography. The purified scFv has an affinity for IL-18R of 5.6 x 10(8) M(-1), whereas 117-10C binds to the receptor with an affinity constant of 3.6 x 10(9) M(-1). Since 117-10C is of the IgM class, it is expected to be in the pentamer form and should theoretically therefore bind IL-18R with 10 times the affinity of the single-chain fragment may explain the difference in the affinity constants for the two molecules. The inhibitory efficiency of 117-10C was found to be 6-fold that of scFv in an interferon gamma (IFN-gamma)-inducing assay on the IL-18-responsive cell line KG-1. In conclusion, we have produced a single-chain fragment of a murine anti-human IL-18R antibody that is as potent at binding IL-18 as the parent antibody, and may be useful in neutralizing the cytokine in human conditions associated with high production of IL-18.

Amino Acid Sequence↗

PubMed1998

Time-dependent cyclosporine A-induced nephrotoxicity in rats.

1. We investigated the toxicity of cyclosporine A (CsA) with reference to the timing of its administration in rats. 2. To elucidate the time-dependent effects of CsA on renal function and survival rate, CsA (75 mg/kg per day) or vehicle was orally administered once daily at four different times (3, 9, 15 and 21 h after lights on; HALO) over a period of 21 days to male Wistar rats (n = 56) kept in rooms with a 12 h light-dark cycle. 3. On the 7th day after treatment, creatinine clearances (Ccr) of groups dosed at 3 and 9 HALO (inactive period) were not reduced in comparison with clearances of time-matched control rats, whereas Ccr significantly decreased in rats dosed at 15 and 21 HALO (active period). Cyclosporine A markedly increased urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion in all dosed groups at the 7th day after treatment, except for rats dosed at 3 HALO. In rats dosed at 3 HALO, Ccr decreased progressively; however, it did not decrease progressively in rats dosed at 9 HALO. In surviving rats treated during the inactive period, urine NAG subsequently returned to control levels. Survival rates were greater in animals dosed during inactive periods than those in groups dosed during active periods. 4. Significant differences in CsA-induced toxicity were obvious as a result of the timing of its administration. A different time course between Ccr and urine NAG excretion was observed during repeated CsA administration. Degenerative changes in proximal tubules were demonstrated after chronic administration of CsA, suggesting that severe and persistent tubular damage cannot be assessed by urinary NAG excretion.

Acetylglucosaminidase↗

PubMed1998

Papillary squamous cell carcinoma of the uterine cervix: diagnostic pitfalls.

A case of papillary squamous cell carcinoma (PSCC) of the uterine cervix is reported. The patient was a 73-year-old Japanese woman with acute renal failure and bilateral hydronephrosis. A cauliflower-like mass was found in the uterine cervix. A uterine cervical biopsy specimen revealed PSCC in situ, while clinically it was an invasive carcinoma. Uterine cervical biopsy was performed a second time to confirm its stromal invasion. However, only small fragments were obtained because of heavy bleeding from the tumor and they showed PSCC in situ again. Following this, computed tomography of the pelvis revealed a 5 cm mass in the uterine cervix, invading the vagina and urinary bladder. Though deep-wedge biopsy, loop electrosurgical excision, or cone biopsy is recommended to evaluate PSCC, it may be impossible to perform any of these procedures because of bleeding such as that seen in our case. In these circumstances, good communication between pathologists and clinicians is important since lack of communication may cause PSCC to be microscopically misinterpreted as in situ carcinoma rather than invasive carcinoma.

Aged↗

PubMed1998

Effects of low phosphate intake on bone and mineral metabolism in rats: evaluation by biochemical markers and pyridinium cross-link formation in bone.

We have investigated the changes in biochemical markers and in pyridinium cross-links in bone in hypophosphatemic rats. Six-week-old female Wistar rats were divided into two groups (normal diet and a phosphate-deficient diet) and fed for 8 weeks. A low phosphate intake caused a significant difference in the concentrations of osteocalcin and alkaline phosphatase with advancing rachitis as well as an increase in bone resorption marker concentrations in urine. Femur biochemical analysis revealed a significant (p < 0.005) increase in deoxypyridinoline per mole collagen in the phosphate-deficient group which suggested that urinary excretions of pyridinium cross-links might reflect not only bone resorption but also increased pyridinium cross-links in bone matrix collagen. Our results demonstrate that a low phosphate intake causes an increase of pyridinium cross-link formation as well as a discrepancy between the circulation levels of alkaline phosphatase and osteocalcin with advancing rachitis. These alterations induced by low phosphate intake should be considered when interpreting the values of biochemical markers.

Alkaline Phosphatase↗

PubMed1998

Cerebral hematocrit decreases with hemodynamic compromise in carotid artery occlusion: a PET study.

BACKGROUND AND PURPOSE: This study investigated whether in patients with internal carotid artery occlusion the regional cerebral hematocrit correlates with cerebral hemodynamics or metabolic state and, if so, how the regional cerebral hematocrit changes in the hemodynamically compromised region. METHODS: We used positron emission tomography to study seven patients with unilateral internal carotid artery occlusion and no cortical infarction in the chronic stage. The distributions of red blood cell and plasma volumes were assessed using oxygen-15-labeled carbon monoxide and copper-62-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The calculated hematocrit value was compared with the hemodynamic and metabolic parameters measured with the oxygen-15 steady-state technique. RESULTS: In the cerebral cortex, the value of the cerebral hematocrit varied but was correlated with the hemodynamic and metabolic status. Stepwise regression analysis revealed that the large vessel hematocrit, the cerebral metabolic rate of oxygen, and the cerebral blood flow or the oxygen extraction fraction accounted for a significant proportion of variance of the cerebral hematocrit. The oxygen extraction fraction and the cerebral metabolic rate of oxygen negatively correlated with the cerebral hematocrit, whereas the cerebral blood flow correlated positively: patients with reduced blood supply relative to metabolic demand (decreased blood flow with increased oxygen extraction fraction) showed low hematocrit values. CONCLUSIONS: In carotid artery occlusion in the chronic stage, regional cerebral hematocrit may vary according to cerebral hemodynamics and metabolic status. Regional cerebral hematocrit may decrease with hemodynamic compromise unless oxygen metabolism concomitantly decreases.

Aged↗

PubMed1998

Successful treatment of anomalous origin of the left coronary artery from the pulmonary artery in a 5-week-old male infant.

A 5-week-old male infant who was referred to our hospital because of tachypnea and poor feeding. An electrocardiogram showed a deep Q wave in lead aVL, negative T waves in leads I, II, III, aVF and V6 and a positive T wave in VL. Echocardiography revealed severely impaired left ventricular function. Aortography confirmed with a diagnosis of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA). Takeuchi's procedure was performed and the patient maintained postoperatively on assisted circulation for 7 hours even though sternal closure delayed until 7 days post operatively. His left ventricular function showed and marked improvement gradually.

Assisted Circulation↗

PubMed1998

Elevation of plasma peptide YY and pancreatic juice hypersecretion following massive small bowel resection in the rat.

To clarify a physiological role of endogenous peptide YY(PYY) on pancreatic exocrine secretion, gastrointestinal transit and bile flow, a hyper-PYY-emia model was constructed by performing a massive small bowel resection using rats. (1) 75% resection of the small intestine was performed at its distal side. Two weeks after surgery, these rats were fed a liquid meal, and intestinal transit of contents was observed and plasma PYY and secretin concentrations were measured by radioimmunoassay. (2) Two weeks after the same surgery, a liquid meal was infused into the duodenum, and both pancreatic juice and bile were collected separately under general anesthesia. Transit of the intestinal contents from the pyloric ring, plasma CCK concentrations, pancreatic juice flow, amylase output, and bile flow were determined. Hyper-PYY-emia occurred following surgery both at fasting and after feeding, accompanied by retardation of gastrointestinal transit, increase of pancreatic juice flow and decrease of bile flow. Plasma secretin levels were elevated slightly, while CCK levels remained unchanged. In conclusion, massive small bowel resection is a useful model to induce hyper-PYY-emia in rats. It is considered that, in a malnutritional state after small intestinal resection, a colonic regulatory mechanism, via humoral factors such as PYY, participates in the feedback regulation of proximal intestinal as well as of pancreatic function.

Animals↗

PubMed1998

Signet ring cell carcinoma of the stomach: a clinicopathological comparison with the other histological types.

A retrospective analysis was carried out on 93 patients with signet ring cell carcinoma of the stomach operated on between 1985 and 1995, to review the clinicopathologic characteristics from the database of gastric cancer at Sendai National Hospital. The results were compared with those for 590 patients with other types of gastric carcinoma. Women were afflicted as commonly as men in the signet ring cell carcinoma group. These patients tended to be younger and to have larger tumors. The histological type was commonly scirrhous and infiltrative. The survival of patients with signet ring cell carcinoma was worse than that of patients with other types of gastric cancer but the difference was not statistically significant. Patients with early signet ring cell carcinoma had a good prognosis, similar to that of the other groups. However, prognosis of patients with advanced signet ring cell carcinoma was poor compared with patients with other types of this disease. In multivariate analysis, the statistical significant prognostic factors were vascular microinvasion and tumor location. These findings suggest that signet ring cell carcinoma of the stomach should be regarded as a distinct type of gastric cancer.

Age Distribution↗

PubMed1998

Associations of attributional dimensions with emotions in academic achievement.

To examine relationships between causal dimensions and affects in academic achievement, 87 college students were asked to complete a questionnaire, designed to assess their reactions to the outcome of a midterm examination. The questionnaire consisted of two kinds of measures, causal dimensions and affects. Multiple regression analysis showed the relations of attributional dimensions and the midterm examination outcome to the affective reactions; these results were discussed.

Achievement↗

PubMed1998

Excretion of triethyllead, diethyllead and inorganic lead in rabbits after injection of triethyl neopentoxy lead.

Triethyl neopentoxy lead (TEneoPOL: (C2H5)3Pb [OCH2C(CH3)3] liquid) was administered to rabbits in a single dose of 10 mg/kg body weight (5.4 mg Pb/kg body weight), and the urinary and fecal excretions of lead were measured to determine the fate of this triethyllead derivative. About 4% of the administered amount of was excreted into the urine during the 7 days after the injection; and about 68%, into the feces. In other words, the fecal excretion of total lead was about 17 times as great as the urinary excretion. About 85% of the urinary excretion of total lead was composed of diethyllead (Et2Pb2+), and about 92% of the fecal excretion consisted of inorganic lead (Pb2+). The major chemical species of lead excreted in the urine was Et2Pb2+, while the major species excreted in the feces was Pb2+. These results were similar to those of administration of tetraethyllead (Et4Pb) to rabbits. One of the 7 rabbits died on the day following the injection, and TEneoPOL, a triethyllead derivative, proved to be no less toxic than Et4Pb. However, this compound is immediately hydrolyzed by the ambient moisture to form a white solid compound, so that it is not accompanied by as great a risk of airway exposure as Et4Pb.

Animals↗

PubMed1998

[Thoracoscopic surgery using voice controlled robot for spontaneous pneumothorax].

We investigated the feasibility and applicability of using voice controlled robot-assisted thoracoscopic surgery for spontaneous pneumothorax. Eleven patients with spontaneous pneumothorax were involved in this study. Five patients were treated by voice controlled robot-assisted thoracoscopic procedure and 6 by historical human-assisted thoracoscopic procedure. All procedures were successfully completed without complications. The number of times the thoracoscope required cleaning per 60-minute interval for cases involving voice controlled robot-assisted surgery were 1.4 compared to 8 per 60-minute interval for comparable cases when the robot was not used. Operative times, the amount of analgesics, the duration of indwelling chest tube, the number of recurrences after operation during thoracoscopic procedures were not statistically different. We found that use of voice-controlled robot as surgical assistant during thoracoscopic surgery for spontaneous pneumothorax is feasible.

Adolescent↗

PubMed1998

[A voice-controlled robot assisted thoracoscopic surgery for pulmonary tumor].

We herein report a case of voice-controlled robot assisted thoracoscopic surgery for a right apical tumor in a 55-year-old male. The patient was referred to our hospital for further examination of an abnormal shadow on chest X-ray. A chest computed tomographic scan indicated a suspicion of malignancy. Thoracoscopic surgery using a voice-controlled robot was conducted. The thoracoscope connected with the robotic arm was inserted through the trocar. In all maneuvers (forward and backward, right and left, up and down, insertion and extraction), the robotic arm moved appropriately immediately after the voice commands were issued, and favorable operative fields were obtained. Thoracoscopic partial resection of the involved lung was successfully performed with no complications. The operative time was 140 min. The postoperative course was uneventful. Voice-controlled robotic technology innovations may become the operating surgeon's third arm in the future. They will be further used not only in laparoscopic but also in thoracoscopic surgical procedures. Regular use will lead to greater skill in thoracoscopic application with the advent of new robotically assisted endoscopic surgery.

Antitubercular Agents↗

PubMed1998

[Endoscopic treatment with laryngeal masks for the removal of tracheobronchial foreign bodies].

We studied the endoscopic removal of tracheobronchial foreign bodies from 13 patients. Eight patients were treated under local anesthesia and 5 under general anesthesia. Complications included mild bleeding during endoscopic treatment of 3 patients. One patient was placed under general anesthesia because the patient was irritable and because hemorrhage made observation difficult. Laryngeal masks were used in 4 cases, and resulted in no complications. The follow-up courses ranged from 4 months to 12 years and were uneventful for all patients. Use of a fiberoptic bronchoscope in combination with laryngeal masks facilitated the management and removal of tracheobronchial foreign bodies by providing a secure airway and by minimizing the effect on the cardiorespiratory system.

Adult↗

PubMed1998

[Use of laryngeal mask in bronchoscopy or bronchoscopic treatment].

Laryngeal mask which is widely used in clinical anesthesiology permits establishment of airway without tracheal intubation. Flexible bronchoscopy or bronchoscopic treatment using the laryngeal mask was evaluated to determine its safety, less invasiveness, and usefulness. Fifty-two patients underwent flexible bronchoscopy or bronchoscopic treatment using laryngeal mask 54 times. Bronchoscopy was performed under either local or general anesthesia. The laryngeal mask was positioned in the larynx, as a rule without a laryngoscope. A flexible bronchoscope was introduced into the airway, passed through the rubber slit at the tip of the laryngeal mask tube, and the examination was performed. Complications observed during the course of the examinations consisted of only two cases of poorly fitting laryngeal mask and one case of catching of a part of the epiglottis in the rubber slit at the tip of the laryngeal mask tube. Both cases were not particularly problematic. There were three patients with sore throat and one with an unpleasant feeling in the pharynx following the examination, however, all of these complaints resolved within three days after the examination. Laryngeal masks are less invasive and have very little effect on either the respiratory system or the circulatory system. They may be used safely even in aged patients and appears to be highly effective for diagnostic and therapeutic bronchoscopy.

Adolescent↗

PubMed1997

A simple and sensitive bioassay for the detection of human interleukin-18/interferon-gamma-inducing factor using human myelomonocytic KG-1 cells.

Interleukin-18 (IL-18)/interferon-gamma-inducing factor (IGIF) is a novel cytokine which plays an important role in Th1 responses. Here we describe a simple, sensitive bioassay for human IL-18 using the human myelomonocytic cell line, KG-1, which produces IFN-gamma in response to human IL-18. IFN-gamma production induced by human IL-18 was completely blocked by an antibody against human IL-18. Human IL-18 could be measured in a concentration range from approximately 100 to 10,000 pg/ml, and intra- and inter-assay coefficient variations were both below 15%. It was possible to measure human IL-18 in human serum, cell lysate or culture supernatant by this bioassay. Thus, the human IL-18 bioassay can be expected to be useful in the investigation of the relationship between human IL-18 and various diseases or in analyzing the mechanisms of human IL-18 secretion from IL-18 producing cells.

Animals↗