Biomedical subjects

Y Miyazawa

Publications and source records attributed to Y Miyazawa.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Detection methods for drug-resistant bacteria in routine examination--VRE].

When testing vancomycin susceptibility against enterococci, plates should be held a full 24 hours then examined using transmitted light. The presence of a haze or any growth within the zone of inhibition indicates resistance. Perform vancomycin MIC and tests for motility and pigment production to distinguish species with acquired resistance(vanA and vanB) from those with intrinsic, intermediate-level resistance to vancomycin(vanC) such as E. gallinarum, E. casseliflavus or E. flavescens.

Enterococcus↗

PubMed2000

[Measures for the disposal of non-regulated alternative medical wastes--effects of disinfectants on activated sludges].

Effects on activated sludges of several disinfectants with strong and wide antimicrobial ability, were investigated using an oxygen up-take method. As a results, at the maximal non-reactive concentration of disinfectants, hexachlorophene has estimated value of 6 mg/l and shows the highest toxicity against activated sludges. At the lethal concentration of 50%, the toxicity of triclosan is the strongest disinfectant.

Bacteria, Aerobic↗

PubMed2000

[Pure sensory stroke due to a pontine lesion: a study of clinical symptomatology and somatosensory evoked potential findings].

We studied clinical symptomatology and somatosensory evoked potentials(SEP) of 7 pure sensory stroke patients due to pontine lesions. Clinical symptoms were examined by modality(pinprick, touch, vibration and joint position sense), intensity and distribution of the sensory disturbance. SEP were recorded by the median nerve stimulation in the upper extremities, and the posterior tibial nerve stimulation in the lower extremities. Patients 1-4 were characterized by decreased contra-lesional fingers or fingers, toes joint position sense, normal pinprick and vibration sense. We think that these patients' lesions were localized in the lemniscus medialis. Patients 5-7 were characterized by decreased contra-lesional upper extremity or upper and lower extremity vibration sense, decreased pinprick sense and normal joint position sense. We think that these patients' lesions involved spinothalamic tract. There was no abnormal finding of SEP with upper extremity stimulation, but disappearance or very low amplitude of P38 with lower extremity stimulation in 4 of the 7 patients. We conclude that 1) the vibration sense may be conducted also through the spinothalamic tract, 2) SEP findings are abnormal only with lower extremity stimulation in pontine pure sensory infarction.

Evoked Potentials, Somatosensory↗

PubMed2000

[Problems in measurement of forced vital capacity--quality assessment with extrapolated volume].

In 1994, the American Thoracic Society proposed criteria for the start of expiration, middle of expiration and end of expiration in order to improve the accuracy of forced vital capacity measurement. Extrapolated volume (EV) and percent extrapolated volume (%EV), which serve as the criteria for the start of expiration, were studied in this paper. It was demonstrated that the values of %V50 and %FEV1.0% increased incorrectly when EV or %EV were outside the criteria because of an erroneous start point for expiration or poor technique. Similar results were obtained in the same subjects, who underwent FVC measurement more than twice with different effort levels. The present study demonstrated that obstructive ventilatory impairment may be underestimated if EV or %EV is outside the criteria. We concluded that the values of EV and %EV are parameters which indicate a rapid rise of the internal pressure of the thoracic cavity at the start of expiration and should be considered in seeking correct measurement of respiratory function including FVC.

Adult↗

PubMed2000

[A case of acute type adult T cell leukemia and human T-lymphotropic virus type I associated myelopathy who presented meningitis and polyradiculoneuropathy and improved with steroid treatment].

We reported a 35-year-old male patient with acute type adult T cell leukemia(ATL) and human T-lymphotropic virus type I associated myelopathy. He presented meningitis and polyradiculoneuropathy and improved with steroid treatment. He presented headache and sensory ataxia and these symptoms responded to steroid treatment. The usual clinical features of ATL were absent at onset. There existed ATL-like cells in the cerebrospinal fluid and HTLV-I proviral DNA in the blood. Therefore, we surmised that there was monoclonal hyperplasia of the infected cells. He presented ATL after 2 years remission. We pointed out that there was acute type of ATL in patients with meningitis and polyradiculoneuropathy, for which steroid treatment could be effective.

Adult↗

PubMed1999

Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage.

BACKGROUND: Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected. OBJECTIVE: To search for new anatomic substrates for focal retrograde amnesia. METHODS: We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis. RESULTS: Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests. CONCLUSIONS: A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

Adult↗

PubMed1999

Primary Non-Hodgkin's Lymphoma of the Male Breast: A Case Report.

A 69-year-old Japanese man presented with bilateral gynecomastia and a soft, mobile and clearly defined mass beneath the left nipple. A round radiopaque masswas revealed on mammography. The tumor was homogeneous, hypoechoic and measured2.4 x 3.9 cm on ultrasonography. Based on a diagnosis of malignant lymphoma by needle aspiration cytology, a modified radical mastectomy with ipsilateral axillary lymph node dissection was performed. Malignant diffuse large B-cell type lymphoma was diagnosed histologically. Whole body examinations revealed no evidenceof other tumors. Three courses of adjuvant CHOP therapy were subsequently performed. The patient is free of recurrence 12 months after surgery. Primary non-Hodgkin's lymphoma (NHL) of the male breast is extremely rare. The occurrence of lymphoma in this patient could be related to elevated estrogen levels.

Journal Article↗

PubMed1999

Case of gonadoblastoma in a 9-year-old boy without physical abnormalities.

BACKGROUND: A 9-year-old boy was admitted to Jikei University Hospital complaining of gradual enlarging of the left scrotal contents. METHODS/RESULTS: Physical examination was significant for bilateral descended testicles. No abnormalities were detected in the testicles or along the spermatic cords. Scrotal ultrasound showed that hyperechoic shadows were recognized in the central area of the left testicle. Subsequent testicular biopsy and histopathological examination showed intratubular malignant germ cells in the testicular tubules. One week later, left orchiectomy was performed. CONCLUSIONS: Histopathological evaluation revealed gonadoblastoma. Gonadoblastoma, a rare gonadal neoplasm, is composed of germ cells and sex cord derivatives and usually occurs in phenotypically female patients with gonadal dysgenesis. To date, only three cases of gonadoblastoma have been reported in anatomically normal male patients with scrotal testicles. We report on a case of gonadoblastoma unaccompanied by a germ cell tumor in a physically normal male.

Child↗

PubMed1999

Papillary renal cell carcinoma: clinicopathological characteristics and evaluation of prognosis in 42 patients.

OBJECTIVE: To determine the clinicopathological characteristics of histologically defined papillary renal cell carcinoma (RCC) in relation to prognosis. PATIENTS AND METHODS: In total, 768 patients with RCC underwent nephrectomy at our university hospital between 1957 and 1995. RCC was classified into clear-cell carcinoma in 689 patients (89.7%, no follow-up in 14), chromophobe cell carcinoma in 36 (4.7%, no follow-up in two) and papillary RCC in 43 (5.6%, no follow-up in one). In the present study, the 42 patients with papillary RCC who underwent nephrectomy and were followed up were those in whom the clinicopathological features of the papillary RCC were assessed. Factors assessed were the presence or absence of foam-cell infiltration, occurrence of bleeding and/or necrosis, presence or absence of a pseudocapsule, mixed occurrence with clear-cell carcinoma, presence or absence of solid variants, cytoplasmic appearance (basophilic vs eosinophilic cells), stage, nuclear grade of malignancy, and angiographic appearance in relation to prognosis. The prognosis was also compared among patients with clear-cell, chromophobe cell and papillary RCC. RESULTS: The prognosis was significantly better in patients with foam-cell infiltration (P=0.03), with a pseudocapsule (P=0.07), with no solid variants (P=0.001) and with basophilic cells (P<0.001). There were also significant differences in survival between patients with low-stage (1+2) and high-stage (3+4) disease (P=0.003), and among grades 1-3 (grade 1 vs 2, P=0.05; grade 1 vs 3, P<0.001, grade 2 vs 3, P=0.006). Furthermore, the prognosis in patients with papillary RCC was worse than in those with chromophobe cell carcinoma (P=0.02), but there was no significant difference in survival between patients with papillary RCC and those with clear-cell carcinoma. CONCLUSION: The clinicopathological features (e.g. the presence or absence of foam cells, of a pseudocapsule and of solid variants, cytoplasmic appearance, and the stage and nuclear grade of malignancy) are important prognostic factors for patients with papillary RCC. Furthermore, the prognosis in patients with papillary RCC is similar to those with clear-cell carcinoma.

Adolescent↗

PubMed1999

Auxin and cytokinin have opposite effects on amyloplast development and the expression of starch synthesis genes in cultured bright yellow-2 tobacco cells.

In cultured Bright Yellow-2 (BY-2) tobacco (Nicotiana tabacum) cells, the depletion of auxin (2,4-dichlorophenoxyacetic acid) in the culture medium induces the accumulation of starch. This is accelerated by the addition of cytokinin (benzyladenine). Light and electron microscopic observations revealed that this amyloplast formation involves drastic changes in plastid morphology. The effects of auxin and cytokinin on amyloplast development were investigated by adding auxin or cytokinin to cells grown in a hormone-free culture. Auxin repressed amyloplast development, whereas cytokinin accelerated starch accumulation regardless of the timing of hormone addition. RNA gel-blot analysis revealed that the accumulation of the ADP-glucose pyrophosphorylase small subunit gene (AgpS), granule-bound starch synthase, and starch branching enzyme transcripts were also affected by hormonal conditions. High levels of AgpS, granule-bound starch synthase, and starch branching enzyme transcripts accumulated in amyloplast-developing cells grown in auxin-depleted conditions. Furthermore, the addition of auxin to the cells cultured in hormone-free medium reduced the level of AgpS transcripts, whereas the addition of cytokinin increased it, irrespective of the timing of hormone addition. These results suggest that auxin and cytokinin exert opposite effects on amyloplast development by regulating the expression of the genes required for starch biosynthesis.

1,4-alpha-Glucan Branching Enzyme↗

PubMed1999

[Extended-spectrum beta-lactamase (ESBL) produced by Escherichia coli and Klebsiella pneumoniae isolated from Teikyou University Hospital--the first report].

We studied the cefotaxime (CTX)-resistant (MIC > or = 32 micrograms/ml) clinical isolates of E. coli and K. pneumoniae in Teikyo University Hospital from 1990 to 1996. The incidence of CTX-resistant isolates was 0.4% (6/1,282) in E. coli and 0.6% (7/1,044) in K. pneumoniae, in 1990. In 1995, the incidence of CTX-resistance increased to 1.7% (50/2,910) in E. coli (p = 0.0013) and 7.2% (144/1,996) in K. pneumoniae (p < 0.0001). These species have been detected in the stool (86 isolates), urine (59 isolates), sputum (15 isolates), pus (15 isolates), throat (10 isolates) and others (12 isolates) in 1995. MIC50 of ampicillin (ABPC), ABPC with clavlanic acid (CVA) 5 micrograms/ml, piperacillin (PIPC), PIPC with CVA 5 micrograms/ml, ceftazidime, CTX, ceftizoxime, cefpodoxime, cefepime, aztreonam, cefmetazole, latamoxef, and imipenem used against 33 isolates (11 isolates of E. coli, 22 isolates of K. pneumoniae), which were detected in 1996-1997, was > 512 micrograms/ml, 8 micrograms/ml, > 512 micrograms/ml, 8 micrograms/ml, 4 micrograms/ml, > 512 micrograms/ml, 16 micrograms/ml, > 512 micrograms/ml, 256 micrograms/ml, 32 micrograms/ml, 2 micrograms/ml, 0.25 microgram/ml and 0.25 microgram/ml, respectively. This susceptibility pattern were very similar to the Toho-1 type beta-lactamases producing strains.

Cefotaxime↗

PubMed1999

[Trial of oral administration of Bifidobacterium breve for the prevention of rotavirus infections].

It was investigated that Bifidobacterium breve YIT4064 (B. breve YIT4064), Which had augmented IgA production and prevented rotavirus-induced diarrhea in mice, prevented rotavirus infection in infants. The effect of B. breve YIT4064 was evaluated in ten infants from an infants home who received 50 mg of the bacterium every day for 28 days (the B. breve group). Nine infants did not receive this (the control group). Though rotavirus shedding in the control group was detected from 2 (a total of 5 stool samples) of 9 infants (a total of 112 stool samples), it was not detected in any infants (a total of 133 stool samples) in the B. breve group during the administration period. From day 8 to day 14 of the test, rotavirus shedding was detected from 4 of 32 stool samples in the control group, but was not detected at all from 38 stool samples in the B. breve group. The frequency of rotavirus shedding in the B. breve group was significantly lower than that in the control group. Further, the frequency in appearances of anti-IgA in stool samples in the B. breve group showed a tendency to increase in comparison with the control group from day 8 to 14 of the test. The oral administration of B. breve YIT4064 significantly decreased rotavirus shedding in stool samples and prevented rotavirus infection.

Administration, Oral↗

PubMed1999

Recombinant human bone morphogenetic protein-2 stimulates osteoblastic differentiation in cells isolated from human periodontal ligament.

Periodontal ligament cells may play an important role in the successful regeneration of the periodontium. We investigated the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2), one of the most potent growth factors that stimulates osteoblast differentiation and bone formation, on cell growth and osteoblastic differentiation in human periodontal ligament cells (HPLC) isolated from four adult patients. rhBMP-2 induced no significant changes in cell growth in any of the HPLCs. rhBMP-2 at concentrations over 50 ng/mL significantly stimulated alkaline phosphatase (ALPase) activity and parathyroid hormone (PTH)-dependent 3', 5'-cyclic adenosine monophosphate accumulation, which are early markers of osteoblast differentiation, in the HPLCs. rhBMP-2 (500 ng/mL) also slightly enhanced the level of PTH/PTH-related peptide receptor mRNA expression in these cells. While interleukin-1 beta enhanced ALPase activity stimulated with rhBMP-2, tumor necrosis factor-alpha inhibited the rhBMP-2-stimulated activity. Interleukin-6 induced no significant changes in ALPase activity stimulated with rhBMP-2. Although HPLCs, whether treated with rhBMP-2 or not, could not produce measurable amounts of osteocalcin, which is a marker of more mature osteoblasts, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] induced osteocalcin mRNA expression and protein synthesis in these cells. rhBMP-2 inhibited 1,25(OH)2D3-induced osteocalcin synthesis in HPLCs at both the mRNA and protein levels. These results suggest that rhBMP-2 provides an anabolic effect on periodontal regeneration by stimulation of osteoblastic differentiation in human periodontal ligament cells, and that this stimulatory effect is differentially modulated by inflammatory cytokines during the course of periodontal regeneration.

Adolescent↗

PubMed1999

HP33: hepatocellular carcinoma-enriched 33-kDa protein with similarity to mitochondrial N-acyltransferase but localized in a microtubule-dependent manner at the centrosome.

Using a new subtraction method and chemically induced rat hepatocellular carcinomas, we identified a hepatocellular carcinogenesis and hepatocyte proliferation-related gene designated hp33 that encoded a 33-kDa protein. The predicted protein was similar to the bovine aralkyl N-acyltransferase and arylacetyl N-acyltransferase. HP33 was restrictively expressed in the liver and kidney, and its gene expression was stimulated in the regenerating liver as well as in hepatocellular carcinoma. Interestingly, it was demonstrated in various hepatic cells that HP33 was localized in regions surrounding the centrosome, where mitochondria were not concentrated. Moreover, its centrosomal localization was evident in the interphase but not in the mitotic phase of the cell cycle. The centrosomal localization of HP33 was dependent on microtubules, and ectopically expressed HP33 was seen at centrosomes even in fibroblasts, which do not exhibit a typical staining pattern of HP33. The centrosomal localization of HP33 became invisible by nocodazole treatment, whereas the mitochondrial staining pattern was not affected by it. In vitro cosedimentation experiments using purified microtubules indicated that HP33 bound to MTs directly and that its MT-binding ability was dependent on the C-terminal basic domain of the protein. These results suggest that, different from early predictions based on its primary structure, HP33 has a growth- and carcinogenesis-related function that may be independent of mitochondrial function.

Acyltransferases↗

PubMed1999

Loss of tumorigenicity of human breast cancer cells engineered to produce IL-2, IL-4 or GM-CSF in nude mice.

Human breast cancer cells (OCUB-M), retrovirally transduced with granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin-2 (IL-2) or IL-4 gene were examined for their antitumor activities in nude mice. Although cell proliferation rates in vitro of these cytokine-producing cells were not significantly different from that of wild-type cells, nude mice that were subcutaneously inoculated with cytokine-producing cells did not develop tumors in contrast to mice that were injected with wild-type cells. Injection of GM-CSF-producing cells into the vicinity of growing wild-type tumors retarded subsequent growth of wild-type tumors. Histological examination of tumors which received GM-CSF-producing cells revealed marked infiltration of mononuclear cells around the tumors. Irradiation of cytokine-producing cells diminished their proliferation capacity but production of cytokine(s) was retained. Therefore, inoculation of irradiated cytokine producer cells into growing tumors can be used as a therapeutic maneuver for breast cancer.

Animals↗

PubMed1999

[Changes in intrapulmonary compression gas volume during measurement of the flow-volume curve].

Changes in intrapulmonary compression gas volume during flow-volume curve measurement were studied in 77 patients with bronchial asthma, 20 patients with emphysema, and 14 patients with pulmonary fibrosis. The peak point of intrapulmonary compression gas volume was observed at FEF 75 in the bronchial asthma and emphysema patients, and of FEF 25 in the pulmonary fibrosis patients. In the bronchial asthma patients, intrapulmonary compression gas volume increased significantly compared to the healthy control groups; that increase was especially obvious in cases where airway obstruction was severe, e.g. when FEV 1.0% was below 69% (p < 0.05). By contrast, the emphysema patients did not exhibit any significant increase in intrapulmonary compression gas volume compared to healthy control groups despite the existence of obstructive impairments. This study demonstrated that the intrapulmonary compression gas volume-curve is a useful index for the diagnosis of pulmonary diseases when combined with measurements of FVC and FEV 1.0%.

Adult↗

PubMed1998

Biological Effects of Heavy Ion Beam on Human Breast Cancers.

BACKGROUND: Radioresistance of the extensive intraductal component (EIC) is amajor limiting factor in breast conserving therapy (BCT). The purpose of the present experiment was to elucidate the biological effects of a carbon beam on human breast cancer cell lines in order to evaluate its clinical benefits in BCT. METHODS: Human breast cancer cell lines, both grown in culture and inoculated into nude mice were subjected to X-ray (200 kV) and heavy ion beam (290 MeV/u carbon beam) irradiation. The relative biological effectiveness (RBE) of the carbon beam and X-ray irradiation was determined at the level of D10 (10% survival dose) on the dose-survival curve. By using a colony forming assay the survival curves of the three cultured cell lines (YMB-I, OUUB-M, CRL-1500) at a linear energy transfer (LET) of 80 keV/µ m were obtained. Cancer established in nude mice was exposed to single-dose and triple-fractionated irradiation at a LET of 50 keV/µm. The growth of tumorsat various doses was observed and the survival curves were determined using thetumor regrowth assay. RESULTS: The RBE of the carbon beam on each cell line ranged from 2.17 to 2.89 (2.59+/-0.37). That of the tumor in nude mice was 1.53 and 2.00 on exposure to single-dose and fractionated irradiation, respectively. CONCLUSION: Human breast cancer cell lines showed high intrinsic sensitivity to a carbon beam and its effects on the tumor were enhanced by fractionated irradiation. It is worthy using carbon beam is applied to use for clinical trials inBCT.

Journal Article↗

PubMed1998

Involvement of intrasinusoidal hemostasis in the development of concanavalin A-induced hepatic injury in mice.

Concanavalin A (Con A) stimulation induces T-cell activation-associated hepatic injury. This study is designed to show the involvement of microcirculatory disturbance in the pathogenesis. Con A administration led to prominent intrasinusoidal hemostasis, which consisted of erythrocyte agglutination, lymphocyte/neutrophil sticking to endothelial cells, and platelet aggregation and degranulation, resulting in a marked decrease in the intrahepatic blood flow and elevation of portal perfusion pressure. After hemostasis, confluent hepatic necrosis occurred within the congested area of liver parenchyma. Reduction in the extent of hemostasis by the treatment with heparin (thrombin inhibitor) or cyproheptadine (serotonin inhibitor) decreased hepatic injury. Pretreatment with either anti-tumor necrosis factor alfa (TNF-alpha) or anti-interferon gamma (IFN-gamma) monoclonal antibody (MAb) moderately decreased hemostasis and hepatic injury, whereas combined use of two MAbs almost perfectly protected mice from these disorders. Complete obliteration of hemostasis and hepatic injury was also accomplished by the pretreatment with FK506 which suppressed TNF-alpha and IFN-gamma production. Intrasinusoidal accumulation of leukocytes and platelets was, however, not blocked by FK506, indicating that Con A activities other than the stimulation of cytokine production are responsible for this event. The administration of anti-CD3 MAb, a T-cell stimulant without agglutination activities, which elevated plasma cytokine levels in a comparable degree without inducing prominent leukocyte infiltration, did not induce hepatic congestion and injury. These findings indicate that the agglutination activities of Con A and T-cell activation mediated TNF-alpha/IFN-gamma production are both required for the induction of intrasinusoidal hemostasis, which is indispensable for the development of hepatic injury.

Animals↗