Biomedical subjects

R Nishimura

Publications and source records attributed to R Nishimura.

At least 91 records · Page 5Linked to original sources

PubMed1998

Ovarian mixed germ cell tumor composed of polyembryoma and immature teratoma.

We report the case of a 41-year-old woman with ovarian mixed germ cell tumor which was composed of polyembryoma and immature teratoma and who had high serum levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). By immunohistochemical methods, AFP was found in yolk sac cells of the embryoid bodies and immature hepatoid tissues, and hCG was found in giant syncytiotrophoblastic cells. She was treated with surgery followed by cisplatin-based combination chemotherapy. She is well, and her serum levels of AFP and hCG have not been elevated for more than 4 years after the treatment.

Adult↗

PubMed1998

Effects of halothane, enflurane, isoflurane, and sevoflurane on slowly adapting pulmonary stretch receptor activity in anesthetized dogs.

The aim of this study was to evaluate the effects of halothane, enflurane, isoflurane, and sevoflurane on slowly adapting pulmonary stretch receptor (SAR) activity in dogs. Eight beagles were anesthetized with an intravenous injection of a mixture of urethane and alpha-chloralose as a basal anesthesia, then vagotomized, artificially ventilated, and chest opened. Single afferent activities from SARs were recorded from the peripheral nerve cut end of the left vagus. Changes in SAR activities with inhalation of halothane, enflurane, isoflurane, and sevoflurane at 1, 1.5, and 2 times the minimal alveolar anesthetic concentration (MAC) were measured, and differences in the discharges within and among four anesthetics were evaluated. As a result, two different types of SARs, low threshold SARs and high threshold SARs, were detected in this study. In all anesthetics, expiratory discharges of low threshold SARs decreased significantly in a dose-dependent manner, whereas inspiratory discharges did not change significantly at any anesthetic level. Discharges of high threshold SARs tended to decrease with increasing anesthetic level; however, no statistical significance was observed at any anesthetic level. Only one exception to these changes was observed at 1 MAC of halothane where no significant decrease in the expiratory discharge of low threshold SARs or significant increase in the discharge of high threshold SARs was induced against a control value. In conclusion, recent inhalation anesthetics, except for halothane at the light anesthetic level, tended to decrease SAR activities depending on the anesthetic level, suggesting attenuation of the Hering-Breuer inflation reflex.

Action Potentials↗

PubMed1998

Malignant phyllodes tumour with a noninvasive ductal carcinoma component.

A malignant phyllodes tumour with a noninvasive ductal carcinoma component is reported. The patient was an 80-year-old Japanese woman with a breast tumour detected by routine physical examination. A simple mastectomy was performed. The excised tumour was 10.5 x 9.4 x 5.4 cm in size and bulged into the skin with ulceration. The macroscopic appearance was that of a phyllodes tumour. Histologically the tumour consisted mainly of stromal components with a leaf-like structure lined by atypical ductal epithelium. The epithelial component showed gradual evolution to intraductal papillary carcinoma in a few areas. The stromal component was composed mainly of fibrosarcoma with areas of osteosarcoma and rhabdomyosarcoma. Neither stromal invasion of intraductal carcinoma nor transition between the stromal and epithelial elements was seen. Three months after the operation, death occurred, with multiple pulmonary and subcutaneous metastases. This case probably represents malignant change in both the stromal and the epithelial components of a phyllodes tumour. Since the two elements were independent, the possibility that a phyllodes tumour may be one of the origins of true carcinosarcoma is raised.

Aged↗

PubMed1998

The fibrotic focus in advanced colorectal carcinoma: a hitherto unrecognized histological predictor for liver metastasis.

A fibrotic focus (FF) is a clearly defined area consisting of fibroblasts and/or collagen fibres arranged in irregular or storiform patterns within tumours. We looked to see whether FF in advanced colorectal carcinoma was associated with distant organ metastasis especially to the liver. The correlation between FF and the presence of synchronous or total (synchronous and/or metachronous) liver metastasis and tumour recurrence was assessed in 77 patients with Dukes B and C advanced colorectal carcinoma treated by resection. The median follow-up period was 21 months. In multivariate analysis, FF significantly increased the relative risk (RR) of synchronous liver metastasis (RR=4.9, P<0.05) and total liver metastasis (RR=4.6, P<0.05). FF also increased the RR of tumour recurrence (RR=2.4), but the increase was not statistically significant. FF is a newly recognized histological indicator of liver metastasis in advanced colorectal carcinoma.

Adenocarcinoma↗

PubMed1998

Responses of laryngeal capsaicin-sensitive receptors to volatile anesthetics in anesthetized dogs.

The responses of laryngeal capsaicin (CAPS)-sensitive receptors to halothane, enflurane, isoflurane and sevoflurane were evaluated in anesthetized spontaneously breathing dogs from the afferent activity of the internal branch of the superior laryngeal nerve. The CAPS-sensitive receptors were clearly distinguished from irritant receptors by their responsiveness to CAPS and their lack of responsiveness to water. All the CAPS-sensitive receptors were significantly stimulated by all volatile anesthetics in a concentration-related manner, and the activation by halothane, enflurane, and isoflurane was significantly greater than by sevoflurane. In contrast, responses of irritant receptors to the volatile anesthetics were divided into three types (stimulation, inhibition or non-response), and did not differ among anesthetics. In conclusion, the present study demonstrated that the CAPS-sensitive receptors were consistently stimulated by halogenated volatile anesthetics and especially by halothane, enflurane, and isoflurane, and that these responses were dissimilar to the variable responses of irritant receptors.

Afferent Pathways↗

PubMed1998

Effects of volatile anesthetics on vagal C-fiber activities and their reflexes in anesthetized dogs.

Effects of halothane, enflurane, isoflurane, and sevoflurane on vagal capsaicin (CAPS)-sensitive C-fibers were elucidated in anesthetized dogs. The CAPS-sensitive C-fibers were significantly stimulated by all volatile anesthetics with a significantly greater response to halothane than with sevoflurane. A significant increase in respiratory frequency (fR) and a significant decrease in tidal volume (VT) were observed with halothane and isoflurane, and a significant increase in fR was observed with sevoflurane. In contrast, a significant decrease in fR was induced by enflurane. The tachypnea induced by halothane, isoflurane, and sevoflurane was significantly reduced or no longer observed after perineural CAPS-treatment or bilateral vagotomy, whereas the slowing of respiration observed with enflurane was not affected by either of these treatments. These results suggest that vagal C-fibers play an important role in the reflex tachypnea that occurs with halothane, isoflurane, and sevoflurane.

Anesthesia↗

PubMed1998

Coagulation abnormalities and thrombotic microangiopathy following bone marrow transplantation from HLA-matched unrelated donors in patients with hematological malignancies.

Thrombotic microangiopathy is a well-known heterogeneous disorder that occurs as a complication of allogenic bone marrow transplantation (BMT). We evaluated 12 consecutive patients receiving HLA-matched unrelated BMT and 12 consecutive recipients of HLA-identical related BMT for the development of bone marrow transplantation-associated thrombotic microangiopathy (BMT-TM) on days 30 and 60 following BMT. A diagnosis was made in four of 12 (33.3%) unrelated compared to none of 12 (0%) HLA-identical cases. Levels of serum lactic dehydrogenase (LDH), fibrin degraded products (FDP) and de novo thrombocytopenia were elevated in eight of 12 patients (66.7%) receiving unrelated donor BMT, and none of the patients receiving related donor BMT. Our findings suggest clinical or subclinical microangiopathic changes may occur frequently in unrelated donor BMT. FDP elevation is possibly an important marker of microangiopathic changes as early complications of BMT.

Adolescent↗

PubMed1998

The influence of obsessive-compulsive neurosis patients' premorbid personality on obsessive-compulsive symptoms and efficacy of medication.

We conducted a survey with the Lynfield obsessive-compulsive symptom questionnaire (revised version) on 48 obsessive-compulsive neurotic patients as the survey subjects. In the factor analysis five factors of obsessions, were identified: (i) the desire for perfection; (ii) compulsive checking; (iii) washing; (iv) feelings of uncleanliness; and (v) anthropophobia. High correlations were noted between these factors. We also investigated the premorbid personalities of obsessive-compulsive neurotic patients with a multidimensional personality scale and obtained an extroversion dimension and neuroticism dimension. The influence of these premorbid personality dimensions on obsessive-compulsive symptoms became clear; (i) neuroticism is related to the levels of obsession after onset, but not related to compulsive behaviors; and (ii) No differences in premorbid personality dimensions were noted between compulsive checking and compulsive washing behaviors. We also studied whether it was possible to predict the efficacy of pharmacotherapy upon obsessive-compulsive symptoms. It was elucidated that the obsessions of those whose premorbid personalities are emotionally stable and extroversive are susceptible to antidepressants. Based on these results, we discussed the usefulness of premorbid personalities in predicting diversity of obsessive-compulsive symptoms, as well as in prediction the efficacy of medication.

Adolescent↗

PubMed1998

Study of the measurement of defense style using Bond's Defense Style Questionnaire.

Two hundred and seventy healthy university students were surveyed in December 1995 using Bond's Defense Style Questionnaire (DSQ) to measure the subjects' defense mechanisms. At the same time, a survey using Byrne's R-S Scale (Repression-Sensitization Scale) of the MMPI (Minnesota multiphasic personality inventory) and five psychiatric symptom indexes (anxiety, sense of inadequacy, sensitivity, depression and impulsive anger) selected from the CMI (Cornell Medical Index-Health Questionnaire) was conducted. Three factors were extracted from the DSQ through factor analysis: immature defenses, neurotic defenses, and mature defenses. The results of analysis of variance revealed the following: (i) for anxiety and anxiety related symptoms, both immature defenses and neurotic defenses indicated principal effect; (ii) for impulsive anger and depression, immature defenses presented principal effect; and (iii) for sensitivity and impulsive anger, interaction between a mature defense style and neurotic defense style was noted. The relationship between defense styles and psychiatric symptoms in healthy people is studied in this paper.

Adolescent↗

PubMed1998

Evaluation of the Japanese health risks induced by global fallout tritium.

Radioactive tritium (3H) generated by the atmospheric nuclear detonation tests has been circulated in the global environment to cause, through various pathways, low-level world-wide contamination of the environment and potential health risks to human beings. In this study, the dynamic performance of tritium in the global environment was modeled considering its transport with foods/feeds imported from all over the world. The mathematical model was examined by comparing the numerically simulated results with the fallout monitoring data. Main results obtained in this study were as follows: (1) The mathematical model developed in this study can reproduce well the global scale tritium circulation and its concentration in food; (2) The excess fatality rate of Japanese by the dietary intake of tritium is estimated to be on the order of 10(-8) y(-1) at present, which is about two orders of magnitude smaller than that by 90Sr; and (3) About 70% of the Japanese internal radiation dose by tritium is due to drinking water. Farm products, especially imported wheat, are secondly important in the Japanese health risk evaluation; its contribution, however, becomes small if the isotopic exchange effect of tritium is considered.

Cesium Radioisotopes↗

PubMed1998

Dural carotid cavernous fistulas: role of conventional radiation therapy--long-term results with irradiation, embolization, or both.

PURPOSE: To evaluate the long-term results of irradiation alone or of embolization with or without irradiation in patients with dural carotid cavernous fistulas (DCCFs). MATERIALS AND METHODS: Between 1984 and 1996, symptomatic DCCFs in 26 patients were treated by using irradiation alone (protocol 1, n = 12) before April 1988 and by using embolization as an initial treatment (protocol 2, n = 14) during and after April 1988. When angiography showed no improvement after embolization, irradiation was added (n = 6). On the basis of drainage flow speed, DCCFs were classified as fast, medium, or slow. RESULTS: With irradiation alone, all six patients with slow- to medium-type DCCFs had cure with a mean follow-up of 62 months. Four of six patients with fast-type DCCFs had cure or improvement, but the remaining two had no change. In the embolization group, irradiation was added in six patients with fast-type DCCFs. With a mean follow-up of 24 months, four of the six patients had cures, one had improvement, and one had no clinical change. Those who underwent protocol 2 had cures significantly earlier than those who underwent protocol 1 (P < .05). CONCLUSION: Conventional radiation therapy resulted in cure of DCCFs in nine (75%) of the 12 patients and in improvement of signs and symptoms in one (8%). Fast-type DCCFs may not always be improved. Radiation therapy may be useful in DCCFs after embolization.

Adult↗

PubMed1998

A rare case of patent ductus arteriosus in a dog with glomerular mesangiolysis.

Rare case of patent ductus arteriosus (PDA) was observed in a 2-year and 9 month-old Miniature Dachshund which had been diagnosed as severe cardiac failure. Pulmonary artery from the right ventricle connected to dilated ductus arteriosus, and pulmonary artery-ductus arteriosus-descending aorta formed a continuous duct, which seemed to be the main route of bloodstream. Ascending aorta from the left ventricle was hypoplastic, and connected to the dilated ductus arteriosus. Glomerular mesangiolysis due to heart failure was also observed in the kidney.

Animals↗

PubMed1998

Repair of ulnar segmental defect by recombinant human bone morphogenetic protein-2 in dogs.

The efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with poly D, L lactic-co-glycolic acid (PLGA)/gelatin sponge complex (PGS) as a carrier on the repair of segmental long-bone defects was evaluated using an ulnar model in dogs. The defect was 2 cm in length and was fixed with bone plating. After implantation of PGS with or without rhBMP-2, the repair process of the defect was evaluated by serial radiography until 16 postoperative weeks. All defects treated with 160 micrograms or 640 micrograms of rhBMP-2/PGS revealed bone union radiographically by 12 postoperative weeks, whereas all defects treated with PGS alone revealed no radiographic evidence of healing throughout the experimental period. In defects treated with 40 micrograms of rhBMP-2/PGS, new bone appeared partially at the defects but did not accomplish union. Bone mineral contents at the defect sites after harvest at 16 weeks postoperatively were significantly (p < 0.05) higher in those treated with 160 micrograms or 640 micrograms of rhBMP-2 than in those treated with 40 micrograms of rhBMP-2 or PGS alone. Histologically, defects radiographically diagnosed as having achieved union showed the appearance of cortical bone and bone marrow cells. These findings suggest the use of rhBMP-2/PGS as a potential bone graft substitute in reconstructive surgery in dogs.

Animals↗

PubMed1998

Femoral nonunion fracture treated with recombinant human bone morphogenetic protein-2 in a dog.

This is the first report on successful treatment of spontaneous nonunion fracture of a dog by use of recombinant human bone morphogenetic protein-2 (rhBMP-2). A 4-year-old Pomeranian dog with a 2-year history of femoral nonunion fracture was treated with implantation of rhBMP-2. The dog had received surgical correction twice prior to the admission but radiography of the affected limb revealed a typical figure of nonunion fracture. Glossly, the fractured ends were sclerotic and the area between the ends was filled with fibrous tissue. After debridement the femoral shaft was fixed by an 8-hole plate. rhBMP-2 at a total dose of 256 micrograms was implanted with a synthetic carrier into the 8-mm defect formed by the debridement. Callus formation responding to rhBMP-2 was radiographically observed at 2 weeks after implantation and the defect reached radiographic union by 8 weeks after implantation. The plate was removed at 9 months after implantation. Any complications were not observed for 5 months after removal of the plate.

Animals↗

PubMed1998

Establishment and characterization of two cell lines derived from canine spontaneous osteosarcoma.

Two new canine osteosarcoma cell lines were established. One (OOS) was established from a 10-year-old female maltese dog with mandibular osteosarcoma and the other (HOS) from a 7-year-old male mongrel dog with scapular osteosarcoma. Histopathological types of OOS and HOS were mixed and fibroblastic cell type, respectively. Transmission electron microscopic features of HOS revealed prominent rough endoplasmic reticulum, suggesting higher malignancy comparing to OOS. Doubling time of OOS and HOS were 45.0 +/- 0.5 hr and 42.0 +/- 0.1 hr, respectively. Alkaline phosphatase activities of OOS and HOS were quite low. Histological features of tumor tissues produced by transplantation of these cells into nude mice were identical to those of original osteosarcomas.

Alkaline Phosphatase↗

PubMed1998

Combination of interleukin-6 and soluble interleukin-6 receptors induces differentiation and activation of JAK-STAT and MAP kinase pathways in MG-63 human osteoblastic cells.

Studies on the role of interleukin-6 (IL-6) in bone metabolism have been accumulating. However, its effects on osteoblasts are still unclear because the results are conflicting depending on the study models employed. We reasoned that these conflicting data are due to variable expression levels of membrane-bound IL-6 receptors (IL-6Rs). In the present study, we found that IL-6 in combination with soluble IL-6R (sIL-6R) consistently caused a marked elevation of alkaline phosphatase and a decrease in proliferation in the human osteoblastic cell line MG-63, which expressed no detectable membrane-bound IL-6R and failed to respond to IL-6. These effects of IL-6/sIL-6R were blocked by neutralizing antibodies to the IL-6 signal transducer gp130, suggesting an involvement of IL-6 signaling in the elicitation of the effects of IL-6/sIL-6R. Upon stimulation with IL-6/sIL-6R, the gp130, cytoplasmic Janus kinases JAK1 and JAK2 were tyrosine phosphorylated. Moreover, signal transducers and activators of transcription STAT1 and STAT3 were also tyrosine phosphorylated, translocated to the nucleus, and bound to the putative STAT-binding DNA elements. In addition, mitogen-activated protein (MAP) kinase was also activated in response to IL-6/sIL-6R These data demonstrate that sIL-6R may enhance the responsiveness of MG-63 cells to IL-6. Thus, IL-6 in collaboration with sIL-6R may modulate differentiation and proliferation of osteoblastic cells, presumably by activating two distinct signaling pathways of JAK-STAT and MAP kinase.

Alkaline Phosphatase↗

PubMed1998

Puberty, IDDM, and death in Japan. Diabetes Epidemiology Research International Study Group.

OBJECTIVE: To investigate the impact of age at onset on the prognosis of childhood IDDM in Japan. RESEARCH DESIGN AND METHODS: The study population consisted of 987 prepubertal-onset and 345 pubertal-onset IDDM cases who were registered by two nationwide surveys and who were diagnosed between 1965 and 1979. The living status was identified as of 1 January 1990 with the ascertainment rate of 96.5%. Prognosis was evaluated by cause- and age-specific mortality rates and life-table analyses; in addition, an attained-age-matched case-control study was analyzed by conditional logistic regression. RESULTS: The adjusted mortality rates per 100,000 person-years for the pubertal-onset cases were significantly higher than those of the prepubertal-onset cases (835 [95% CI 573-1,168] vs. 391 [283-526]). Life-table analyses revealed that the survival rate of the pubertal-onset cases was lower than that of the prepubertal-onset cases for each observation period. Life-table analyses after the age of 15 years indicated that the prognosis of pubertal cases was almost the same as that of the prepubertal cases despite having a shorter duration of diabetes. The attained-age-matched case-control study indicated that the pubertal onset was a potent determinant of death. CONCLUSIONS: The prognosis of pubertal-onset IDDM was considerably poorer than that of prepubertal-onset IDDM.

Accidents↗

PubMed1998

[Prognostic effect of PyNPase (pyrimidine nucleoside phosphorylase) activity in breast cancer].

To clarify the clinical significance of PyNPase (Pyrimidine Nucleoside Phosphorylase)/ PD-ECGF activity in breast cancer, we examined the possible correlation of PyNPase activity to clinicopathological features and prognosis in 195 patients with primary breast cancer between January 1992 through December 1993. The mean PyNPase activity of primary breast cancer, assayed by ELISA method, was 140.6 U/ml, which was between that of benign breast disease (18.2) and recurrent tumors (270.9). In histological type of breast cancer, tumors with solid-tubular carcinoma had significantly higher levels of PyNPase activity. The activity of ER negative or aneuploid tumors was higher than that of ER positive or diploid tumors, respectively. And there was a significant relationship between PyNPase activity and proliferative activity determined by S-phase fraction (SPF) or DNA polymerase alpha. These findings suggested that PyNPase activity was associated with the degree of malignancy. As regards prognosis, in lower SPF (< 16%) group, patients with higher PyNPase activity had significantly lower disease--free survival rates, whereas those with higher activity had a favorable prognosis in the higher SPF (> or = 16%) group. The contradiction might be explained by the possibility that 5-FU derivatives were effective only in patients with high SPF and PyNPase activity, as all patients were treated by a regimen containing 5-FU derivatives. We suggest that PyNPase activity is associated with progression and proliferation of breast cancer, and that it may be useful for prediction of prognosis and therapeutic efficacy of 5-FU derivatives.

Adult↗