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Biomedical subjects

R Nishimura

Publications and source records attributed to R Nishimura.

At least 73 records · Page 4Linked to original sources
PubMed1997

Predictive value of serum medroxyprogesterone acetate concentration for response in advanced or recurrent breast cancer.

Medroxyprogesterone acetate (MPA) is one of the most commonly prescribed drugs for endocrine therapy of metastatic breast cancer. In this study, the serum MPA concentration was measured by high-performance liquid chromatography (HPLC) and evaluated for its usefulness in predicting the response in 79 cases of advanced or recurrent breast cancers. Overall, 29 patients (37%) achieved an objective response. The response rate correlated significantly with the oestrogen receptor (ER) status (P = 0.03), proliferative activity determined by DNA polymerase alpha (P = 0.04), the disease-free interval (DFI) (P = 0.05) and the serum MPA concentration (P < 0.001). Patients with ER-positive tumours, lower proliferative activity, a longer (DFI) or a higher serum MPA concentration responded more frequently. The mean serum MPA concentration in the responders with ER-positive tumours (P = 0.01) or tumours with a lower proliferative activity (P = 0.008) were significantly lower than in cases with ER-negative tumours or tumours with a higher proliferative activity, respectively. Cases with soft tissue metastases showed responses at significantly lower MPA concentrations (P = 0.003) than those with bone or visceral metastases. Furthermore, there was a dramatic decrease in the MPA concentration when a responder with a high concentration became unresponsive to the therapy. Thus, the serum MPA concentration is a determining factor for the response to treatment.

Adult↗
PubMed1997

Wiskott-Aldrich syndrome protein is associated with the adapter protein Grb2 and the epidermal growth factor receptor in living cells.

Src homology domains [i.e., Src homology domain 2 (SH2) and Src homology domain 3 (SH3)] play a critical role in linking receptor tyrosine kinases to downstream signaling networks. A well-defined function of the SH3-SH2-SH3 adapter Grb2 is to link receptor tyrosine kinases, such as the epidermal growth factor receptor (EGFR), to the p21ras-signaling pathway. Grb2 has also been implicated to play a role in growth factor-regulated actin assembly and receptor endocytosis, although the underlying mechanisms remain unclear. In this study, we show that Grb2 interacts through its SH3 domains with the human Wiskott-Aldrich syndrome protein (WASp), which plays a role in regulation of the actin cytoskeleton. We find that WASp is expressed in a variety of cell types and is exclusively cytoplasmic. Although the N-terminal SH3 domain of Grb2 binds significantly stronger than the C-terminal SH3 domain to WASp, full-length Grb2 shows the strongest binding. Both phosphorylation of WASp and its interaction with Grb2, as well as with another adapter protein Nck, remain constitutive in serum-starved or epidermal growth factor-stimulated cells. WASp coimmunoprecipitates with the activated EGFR after epidermal growth factor stimulation. Purified glutathione S-transferase-full-length-Grb2 fusion protein, but not the individual domains of Grb2, enhances the association of WASp with the EGFR, suggesting that Grb2 mediates the association of WASp with EGFR. This study suggests that Grb2 translocates WASp from the cytoplasm to the plasma membrane and the Grb2-WASp complex may play a role in linking receptor tyrosine kinases to the actin cytoskeleton.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Countertorque testing and histomorphometric analysis of various implant surfaces in canines: a pilot study.

As surface roughness may play a role in the mechanical attachment of an implant surface to bone, various implant surfaces have been prepared and analyzed by removal torque (countertorque) or push-out tests in a variety of animal model systems. Rougher surfaces generally have displayed higher mechanical testing values, indicating a stronger implant-bone interface. This pilot study was undertaken to test the countertorque values for integrated threaded implants with surfaces prepared by machining, blasting, and acid-etching, to compare the various implant surface types histomorphometrically for percentage of bone-implant contact under loaded and unloaded conditions, and to determine the degree of correlation between countertorque values and bone-implant contact with varying degrees of surface roughness. The results of this animal investigation suggest that the strength of the bone-implant interface, as determined by countertorque testing, is influenced by different surface characteristics. Acid-etched surfaces resisted countertorque forces more successfully as compared with blasted or machined surfaces. Histologic evaluation of bone contact with the various implant surfaces did not demonstrate a definite advantage for rougher surfaces in regard to percentage of bone contact at the light microscopic level.

Acid Etching, Dental↗
PubMed1997

S-100 protein is a differentiation marker in thyroid carcinoma of follicular cell origin: an immunohistochemical study.

S-100 protein, a dimer of S-100 alpha and S-100 beta subunits (S-100 alpha and S-100 beta), is widely distributed in human tissue, and several papers describing S-100 protein expression in follicular cells of the thyroid have been published. In the present study, 105 cases of thyroid carcinoma (of which 96 were papillary, four follicular, two undifferentiated, and three medullary) were analyzed immunohistochemically for the expression of S-100 protein, S-100 alpha, S-100 beta, and thyroglobulin. In papillary carcinoma, 188 lesions were studied and classified into well differentiated types (56 papillary, 45 follicular) and poorly differentiated types (41 trabecular, four solid, eight squamoid, three tall, and one insular), because the histological structure of each tumor was heterogeneous. The percentage of lesions which expressed positively for S-100 protein and S-100 alpha, respectively, according to type were: papillary, 96 and 99%; follicular, 96 and 100%; trabecular, 95 and 100%; solid, 50 and 50%; squamoid, 50 and 75%; and tall, 33 and 100%. The insular type was negative for both. For papillary carcinoma, well differentiated lesions showed stronger S-100 alpha expression than poorly differentiated lesions. S-100 alpha expression was weaker in follicular and undifferentiated carcinoma than in papillary carcinoma. Medullary carcinoma also expressed S-100 alpha. S-100 beta was positive in lesions that expressed S-100 alpha strongly. Expression of S-100 protein and S-100 alpha protein correlated with thyroglobulin synthesis in the follicular cells. It was concluded that S-100 protein, mainly S-100 alpha, exists in thyroid follicular cells, that it exists in higher quantity in most of the well differentiated lesions but in lower quantity in poorly differentiated or undifferentiated lesions, and that S-100 protein, especially S-100 alpha, is a differentiation marker in carcinoma of thyroid follicular cell origin.

Adenocarcinoma, Follicular↗
PubMed1997

Carcinosarcoma of the uterus: magnetic resonance imaging.

We report the magnetic resonance imaging (MRI) findings with a paramagnetic enhancement agent (gadopentetate dimeglumine (Gd-DTPA)) in a 70-year-old woman with carcinosarcoma of the uterus. In the present patient, the polypoid portion histologically most abundant in the sarcomatous component was strongly enhanced by Gd-DTPA and was clearly demonstrated with high signal intensities on contrast-enhanced T1-weighted images. We suggest that MRI with Gd-DTPA may be clinically useful for detection of carcinosarcoma, and that any patient having endometrial carcinoma with the polypoid portion, which is more strongly enhanced by Gd-DTPA within the tumor, may be suspected of carcinosarcoma.

Aged↗
PubMed1997

Cardiovascular reflex mechanisms by topical instillation of capsaicin and distilled water into the larynx in anesthetized dogs.

Cardiovascular reflex mechanisms by topical laryngeal instillation of capsaicin (CAPS) or distilled water were evaluated in anesthetized chronic tracheostomized dogs. Both CAPS (10 micrograms/ml) and water instillation into the isolated upper airway caused a significant decrease in heart rate (P < 0.05) and a significant increase in blood pressure (P < 0.05) from the values before instillation under both spontaneous and controlled ventilation. The bradycardia was significantly reduced by atropine pretreatment (P < 0.05) and the hypertension was significantly decreased by phentolamine and propranolol pretreatments (P < 0.01). A higher concentration of CAPS (100 micrograms/ml) instillation considerably reduced the response to subsequent CAPS (100 micrograms/ml) instillation, whereas the response to water was sustained, indicating the desensitization of laryngeal CAPS-sensitive endings. All the reflex responses to CAPS and water were eliminated by topical anesthesia with lidocaine. It was concluded that the laryngeal cardiovascular reflex responses were mediated by the afferents such as the laryngeal CAPS-sensitive presumably C-fiber endings or water-responsive receptors and by both the parasympathetic and sympathetic nervous systems as efferents.

Administration, Topical↗
PubMed1997

Inhibitory effects of glucocorticoids on proliferation of canine mast cell tumor.

The inhibitory effect of glucocorticoids (GCs) on proliferation of canine mast cell tumor (MCT) was studied using two types of MCT cells; JuMC cells and LuMC cells derived from spontaneous canine cutaneous and intestinal MCT, respectively. In in vitro study, growth of JuMC cells was significantly inhibited with more than 1 nM GCs and apoptotic-like cell death was seen, while that of LuMC cells was never inhibited even with 10 microM GCs. Growth rate of masses in nude mice developed by inoculation of JuMC cells was reduced in a dose-dependent manner by administration of GC, while growth inhibition of masses developed by inoculation of LuMC cells was minimal with increasing GC doses. Competitive binding studies and Scatchard analysis demonstrated the presence of high-affinity, low capacity GC receptors in both JuMC and LuMC cells. Kd was estimated to be 1.30 nM in JuMC cells and 0.45 nM in LuMC cells, respectively. It is concluded that canine cutaneous MCT cells responded to GCs in vitro and in vivo, whereas intestinal MCT cells did not, though both types of cells had specific GC receptors.

Animals↗
PubMed1997

CT and MR findings of denervated tongue after radical neck dissection.

PURPOSE: To describe the CT and MR findings in the denervated tongue after a radical neck dissection. METHODS: We retrospectively evaluated the radiologic findings in seven patients who had hypoglossal paralysis following radical neck dissection. None of the patients had clinical or radiologic evidence of tumor recurrence. RESULTS: The side of the tongue operated on showed low density on CT scans. At MR imaging, denervated tongues were clearly seen as hyperintense relative to muscle on T2-weighted images; on T1-weighted images, the signal was hypointense to hyperintense, representing increased extracellular water or fatty degeneration. CONCLUSION: In patients who have undergone a neck dissection for a malignant process, abnormal imaging findings in the tongue not only might indicate a recurrence of tumor involving the hypoglossal nerve but also suggest the possibility of postoperative change. Our findings emphasize the importance of the denervated tongue in differentiating inflammatory from neoplastic diseases of the the tongue.

Adult↗
PubMed1997

Cardiopulmonary effects of sevoflurane, compared with halothane, enflurane, and isoflurane, in dogs.

OBJECTIVE: To evaluate cardiopulmonary effects of sevoflurane (Sevo), compared with halothane (Hal), enflurane (Enf), and isoflurane (Iso). ANIMALS: 24 healthy Beagles, randomly assigned to 4 groups of 6 dogs each. PROCEDURE: Dogs under spontaneous ventilation were anesthetized with Sevo, Hal, Enf, or Iso. After minimum elveolar concentration (MAC) of each anesthetic was determined, anesthesia was maintained at light (1 MAC), moderate surgical (1.5 MAC), and deep (2 MAC), stages and cardiopulmonary variables at conscious state (baseline) and each anesthesia stage were measured. RESULTS: In dogs of the Sevo group, heart rate increased significantly from the baseline value at all anesthesia stages. Systemic vascular resistance during Sevo anesthesia decreased gradually with increasing anesthesia stage, which was accompanied by dose-dependent decreases in systolic, mean, and diastolic arterial blood pressures. At 1.5 and 2 MAC Sevo, stroke index decreased slightly but significantly from the baseline value; however, cardiac index was unchanged because of the significant increase in heart rate. Respiratory rate decreased significantly at 2 MAC from that at 1 MAC Sevo. Tidal volume and dead space-to-tidal volume ratio were unchanged at all anesthesia stages of Sevo, resulting in significantly decreased expired and alveolar ventilation at 2 MAC, compared with values at 1 and 1.5 MAC Sevo. PaCO2 increased and pHa decreased significantly, depending on anesthesia stage; PaO2, increased significantly from baseline values, and remained constant because of inhalation of 100% O2. CONCLUSION: Cardiovascular effects of Sevo were greater than those of Hal, similar to those of Iso, and less than those of Enf. Respiratory effects of Sevo were similar to those of Iso at all anesthesia stages, greater than those of Hal at 2 MAC, and less than those of Enf at 1.5 and 2 MAC. Up to the moderate surgical anesthesia stage, Sevo can be used safely in dogs undergoing spontaneous ventilation.

Anesthetics, Inhalation↗
PubMed1997

[A familial case of postural reflex disorder presenting high intensity area mainly in the globus pallidus on T1-weighted cerebral MRI without clear liver damage].

A 56-year-old woman was admitted because of chronic postural reflex disorder. A cerebral MRI revealed symmetrical high intensity area mainly in the globus pallidus on T1-weighted image. The symptom became manifested as gait disturbance from the age of 2 and gradually progressed. Her condition has, however, remained stable since the age of 26. The only sign of parkinsonism was akinesia. There was clear retropulsion but cerebellar ataxia was minimal, and dystonia was negligible. She had no dementia. Her parents were cousins and similar symptoms and high intensity area were found in one of her sisters. Routine liver function tests were normal, with only ICG elevated. Serum copper and ceruloplasmin were normal. A hereditary factor was suspected. There are no similar cases reported in the literature, thus we thought it worth reporting.

Female↗
PubMed1997

[Clinical significance of orthostatic blood pressure decline in patients with Binswanger-type infarction].

We analysed the blood pressure change in 40 patients with Binswanger-type infarction after 10 minutes of 90 degrees head-up tilting to clarify the clinical significance of orthostatic blood pressure decline observed in this disease. We investigated the correlation of orthostatic decline in systolic blood pressure to dementia, gait disturbance and nocturnal decrease in 24-hour variation of systolic blood pressure. Orthostatic blood pressure decline in patients with this disease was significantly marked in comparison with that in 50 patients with lacunar infarction, especially in the males. This blood pressure decline was significant in patients with dementia and moderate or severe gait disturbance, compared with those without such symptoms. There was no difference in orthostatic change between patients suffering from this disease with non-dementia and mild or absent gait disturbance and those with only lacunar infarction. Orthostatic blood pressure decline was found to be correlated significantly with the disorder of nocturnal blood pressure decrease. It is suggested that the decline of blood pressure on standing is a parameter indicating the progression of this disease.

Aged↗
PubMed1996

Syringomyelia and hydrocephalus in a dog.

A 7-year-old spayed female Pomeranian with a 6-month history of progressive paraparesis was determined to have syringomyelia accompanied with hydrocephalus. Magnetic resonance imaging clearly revealed severe syringomyelia in the cervical portion of the spinal cord, which was directly connected to the marked dilated fourth ventricle. Acetazolamide was prescribed for 3 weeks, but the neurologic deficits progressed. Laminectomy of the first and second vertebrae, which is one method of treating this type of syringomyelia in human beings, was performed, and then, acetazolamide was continued. The dog had partial amelioration, and further deterioration was not evident in the 12 months after surgery.

Animals↗
PubMed1996

Socioeconomic and behavioural risk factors for mortality of individuals with IDDM in Japan: population-based case-control study. Diabetes Epidemiology Research International (DERI) US-Japan Mortality Study Group.

The aim of this population-based, one-to-one matched-pair case-control study was to evaluate the factors concerning the markedly increased risk for dying among Japanese subjects with insulin-dependent diabetes mellitus (IDDM) from a social and behavioural perspective. The study was based on the population-based cohort of IDDM subjects in the Diabetes Epidemiology Research International Mortality Study. We studied 90 cases who died and 90 living control subjects, selected from the rest of the cohort, who were matched for sex, birth year, year of diagnosis and duration of diabetes. Socioeconomic and behavioural status were surveyed through a questionnaire. Conditional logistic regression analyses based on 55 respondent pairs revealed that the better educated patients (year of completing education: odds ratio = 0.66) who kept the same physician (number of times a patient changed physician: odds ratio = 2.77) and who attended a clinic specializing in diabetes (attendance at university hospital clinic: odds ratio = 0.18) injecting insulin several times a day (number of injections, odds ratio = 0.31) and more frequently attending the clinic (> or = 12 times per year, odds ratio = 0.23) were at substantially lower risk of death. The results begin to profile the patients with the highest risk of dying who could be identified earlier and undergo intervention treatment.

Adolescent↗
PubMed1996

Lingual carcinoma. Correlation of MR imaging with histopathological findings.

PURPOSE: To determine the utility of MR imaging in the evaluation of lingual carcinomas. MATERIAL AND METHODS: Eleven patients with lingual carcinoma were evaluated with MR imaging including dynamic study within one week before surgery. Nine patients underwent preoperative chemotherapy or irradiation, and 2 patients had no preoperative treatment. Delineation of the tumor, the contrast between tumor and surrounding tissue, and extent of the tumor were evaluated in a blinded manner. After glossectomy, MR images were correlated with pathological findings. Statistical analysis was performed on the visual assessment ratings. RESULTS: Blinded evaluation suggested that dynamic and T2-weighted images (T2WI) were significantly superior to postcontrast T1WI in demonstrating the lesion. There were no significant differences between dynamic MR images and T2WIs. However, histopathological correlation showed that in patients with preoperative treatment, dynamic MR imaging demonstrated more accurately the size and extent of the residual tumor than did T2WI and postcontrast T1WI, which tended to demonstrate an area of signal abnormality that was more extensive than the true size of the residual lesion. In patients without preoperative treatment, dynamic MR imaging, T2WI, and postcontrast T1WI gave an equivalent depiction of the extent of the carcinoma. CONCLUSION: In patients with no preoperative treatment, dynamic MR imaging does not appear to offer any advantage over T2WI. However, in patients with preoperative treatment, dynamic MR imaging provides a more accurate assessment of the residual tumor than do T2WI and postcontrast T1WI.

Aged↗
PubMed1996

Short communication: the value of embolization therapy in painful osseous metastases from hepatocellular carcinomas; comparative study with radiation therapy.

We evaluated the therapeutic effect of transcatheter arterial embolization therapy (TAE) for painful osseous metastases from hepatocellular carcinoma (HCC) in comparison with radiation therapy (RT). TAE using gelatin sponge particles was performed for seven lesions in seven patients. Selective catheterization and embolization were successfully performed in all lesions. Within 10 days after TAE, complete pain relief (CR), partial relief (PR) and no relief (NR) were attained in 57%, 29% and 14%, respectively. RT was used to treat 34 lesions in 22 patients. The dose fractionation schedules were in the range 28.0-50.4 Gy, with 1.8-4.0 Gy per fraction. CR, PR and NR were attained in 47%, 47% and 6%, respectively. There were no serious complications related to these treatments. Both TAE and RT are effective and the treatment of choice should be selected on an individual basis.

Bone Neoplasms↗
PubMed1996

Histopathological changes in digits of dairy cows affected with sole ulcers.

Forty-eight digits of 8 dairy cows, which had been diagnosed as sole ulcers in one or two hooves, were examined histopathologically and classified into 5 grades on the basis of the severity of the circulatory disturbances and of keratogenesis. All the cows had significantly higher grades than normal cows. Although hind lateral digits were most severely damaged, there were no significant differences in the grades among claw positions except hind lateral digits. From these results, it is suggested that the cows affected with sole ulcers had some systemic factors predisposing all the digits to digital disorders.

Animals↗