Biomedical subjects

M Yoshimura

Publications and source records attributed to M Yoshimura.

At least 523 records · Page 29Linked to original sources

PubMed1991

A case of empyema developing thirteen years after a pneumonectomy treated using pedicled omentum which was followed by intestinal obstruction.

Postpneumonectomy empyema is one of the most difficult complications for the thoracic surgeon to treat. We report herein a case of a 62 year old diabetic man who developed empyema 13 years after a pneumonectomy for cancer, which was successfully treated using an omental pedicle flap. Postoperatively, the chest would healed uneventfully, however, a bowel obstruction developed which was subsequently treated by removing the remnant omentum that had adhered to the bowel.

Colonic Diseases↗

PubMed1991

A 24-week study of the microleakage of four retrofilling materials using a fluid filtration method.

The microleakage after retrofillings of amalgam, amalgam with cavity varnish, silver-containing glass ionomer cement, and intermediate restorative material was compared in vitro. Thirty-six extracted human incisors and canines were instrumented, obturated with gutta-percha without sealer, subjected to apicoectomy, and retrofilled with the materials described above. After removal of the gutta-percha filling, the microleakage from both directions (apically and coronally) was measured quantitatively and longitudinally for 24 wk after filling by a fluid filtration technique. All four retrofilling materials revealed some apical and coronal leakage at all time periods. The amalgam group showed statistically significant (p less than 0.001) apical leakage at 1.5 h. The use of cavity varnish significantly reduced the apical leakage of the amalgam group at 1.5 h. The silver-containing glass ionomer cement and intermediate restorative material groups showed significantly (p less than 0.05) less coronal leakage compared with the amalgam group at 1.5 h. Scanning electron microscopy of selected samples showed marginal defects of approximately 5 microns between the root dentin and the retrofilling material.

Cermet Cements↗

PubMed1991

Glutamate receptor agonist-induced inward currents in spinal dorsal horn neurons dissociated from the adult rats.

Inward currents to glutamate receptor agonists, quisqualate (QA), kainate (KA) and N-methyl-D-aspartate (NMDA) were examined in spinal dorsal horn neurons by whole-cell voltage-clamp techniques after acute dissociation. Neurons were dissociated from the superficial dorsal horn (laminae I/II) of the adult rat (8-16 weeks old) spinal cords by enzymatic and mechanical treatment. The KA-induced current was sustained during KA application, while the QA- and NMDA-induced currents were attenuated. The NMDA response was augmented dose-dependently by addition of glycine (10(-7)-5 X 10(-6) M) and became obscure in the absence of glycine. The NMDA current was depressed by D-2-amino-5-phosphonovaleric acid (APV). Analyses of dose-response curves of these inward currents indicate that both the QA and KA currents were competitively blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), while the NMDA current was blocked non-competitively.

2-Amino-5-phosphonovalerate↗

PubMed1991

Chronic intracerebroventricular infusions of endothelin elevate arterial pressure in rats.

We investigated the effects of intracerebroventricular infusions of endothelin on cardiovascular and endocrinological responses using conscious, unrestrained rats. Chronic intracerebroventricular infusions of endothelin, 10 pmol/h for 7 days, elevated arterial pressure significantly on days 5, 6 and 7 of the infusion, compared with intracerebroventricular infusions of the vehicle. Heart rate decreased from day 1 of the infusion of endothelin until the end of the experiment. The urinary excretion of norepinephrine increased on day 3 and epinephrine increased on days 3, 4 and 5 of endothelin infusion. The urinary excretion of arginine vasopressin increased on day 5, 6 and 7 of the infusion. These findings suggest that chronic intracerebroventricular infusions of endothelin elicit elevations in arterial pressure and that the initiation of blood pressure rises can be related to sympathetic activation although the actual role for the pressor responses has been played by the released arginine vasopressin.

Animals↗

PubMed1991

The effects of insulin and insulin-like materials in the brain on central cardiovascular regulation: with special reference to the central effects of sodium chloride.

The present study investigated the roles of insulin on central cardiovascular regulation. When rats were fed with a high-salt diet for 4 weeks, hypothalamic and pituitary contents of insulin-like immunoreactive substance (ILI) significantly decreased. The plasma concentration of ILI remained unaltered, however. Intracerebroventricular injections of insulin significantly decreased both the blood pressure and the heart rate, with corresponding decreases in renal sympathetic nervous activity in urethane-anesthetized rats. Microinjections of insulin into the ventromedial nucleus in the hypothalamus caused greater vasodepression and bradycardia compared with the intracerebroventricular injections. Intracerebroventricular infusions of insulin inhibited the pressor effects of simultaneously-infused hypertonic saline, and the digitalis-like immunoreactivity in both the plasma and the hypothalamus were significantly decreased by the insulin. These results indicate that ILI in the brain affects the central cardiovascular regulation through the suppression of both sympathetic nervous system activity and the release of digitalis-like substances. These mechanisms may operate particularly during a sodium load.

Animals↗

PubMed1991

Effects of intracerebroventricular and intravenous injections of endothelin-1 on blood pressure and sympathetic activity in urethane-anesthetized rats.

Because endothelin-1 (ET-1) is believed to be an endogenous calcium-channel agonist, it was thought that it may affect not only vascular smooth muscle cells but also nerve activity. Intravenous injections of ET-1 (0.01 nmol) did not affect cardiovascular parameters or renal sympathetic activity. ET-1 (1 nmol) initially decreased blood pressure for a few minutes, and then caused an increase for 5-10 min. Blood pressure then returned to baseline but later there was a rise in pressure for more than 60 min. Sympathetic activity was markedly suppressed during the initial hypertensive phase but increased during the later phase. Intracerebroventricular injections of ET-1 increased blood pressure even with the small dose (0.01 nmol). The increase was maintained for about 10 min, and returned to baseline. It then decreased abruptly with marked bradycardia, and finally returned to the baseline 60-90 min later. These results indicate that ET-1 affects not only the vascular smooth muscle but also the autonomic nervous system to influence cardiovascular functions.

Anesthesia↗

PubMed1991

Digoxin-like immunoreactivity increases with intravenous infusion of saline in rats.

1. The effects of sodium-loading on releases of endogenous digitalis-like substance were investigated by measuring digoxin-like immunoreactivity (DLI) during intravenous infusions of isotonic (0.15 mol/L) and hypertonic (1 mol/L) saline in anaesthetized rats. Plasma DLI was measured after death by a digoxin-radioimmunoassay. 2. The infusion of isotonic saline and hypertonic saline elevated the central venous pressure to similar levels. The plasma DLI concentration in both the infused groups rose significantly compared with that in the control rat not receiving the intravenous infusion. 3. The difference in the hypothalamic concentrations of DLI was not significant among the three groups, however, there was a significant inverse relationship between the plasma and hypothalamic concentrations of DLI. 4. Results indicate that the central venous pressure, but not sodium concentration, is essentially involved in the release of DLI, possibly from the hypothalamus.

Animals↗

PubMed1991

Supportive psycho-educational intervention for schizophrenics' families: influencing family dynamics.

I conducted supportive psycho-educational intervention for the families of schizophrenics, mainly to the mothers, and investigated the influence on the patients' mode of treatment and their symptoms 9 months later. In accordance with Motooka, the mothers were classified into the three categories of narcissistic type, symbiotic type and dependent type. The influence of the interventions varied with the difference in types. Only the patients whose mothers belong to the dependent type showed a significant improvement 9 months after the interventions. From these results I consider that the narcissistic type cases need to be given psychotherapeutic family intervention from the early stage of treatment, while symbiotic type cases need supportive psycho-educational intervention in the presence of both parents and dependent type cases merit supportive psycho-educational interventions to the mothers.

Adolescent↗

PubMed1991

Hemodynamic, renal, and hormonal responses to brain natriuretic peptide infusion in patients with congestive heart failure.

BACKGROUND: This study was designed to examine the hemodynamic, renal, and hormonal effects of brain natriuretic peptide (BNP) infusion in patients with congestive heart failure (CHF) and in control subjects. METHODS AND RESULTS: We infused synthetic human BNP at a rate of 0.1 micrograms/kg/min. BNP infusion decreased pulmonary capillary wedge pressure (control, from 5 +/- 1 to 2 +/- 1 mm Hg, p less than 0.01; CHF, from 21 +/- 3 to 14 +/- 4 mm Hg, p less than 0.05) and systemic vascular resistance (control, from 1,264 +/- 75 to 934 +/- 52 dyne.sec.cm-5; CHF, from 2,485 +/- 379 to 1,771 +/- 195 dyne.sec.cm-5; p less than 0.01, respectively) and increased stroke volume index (control, from 49.9 +/- 2.7 to 51.5 +/- 2.3 ml/m2, p = NS; CHF, from 25.6 +/- 3.8 to 32.0 +/- 3.9 ml/m2, p less than 0.01). BNP infusion significantly increased urine volume (control, from 2.3 +/- 0.7 to 7.5 +/- 1.9 ml/min; CHF, from 0.8 +/- 0.2 to 5.3 +/- 1.0 ml/min; p less than 0.01, respectively), excretion of sodium (control, from 79.2 +/- 21.6 to 332.8 +/- 70.9 microEq/min; CHF, from 77.4 +/- 20.8 to 753.5 +/- 108.0 microEq/min; p less than 0.01, respectively), and excretion of chloride (control, from 72.5 +/- 18.4 to 256.0 +/- 43.3 microEq/min; CHF, from 74.0 +/- 19.6 to 708.8 +/- 103.3 microEq/min; p less than 0.01, respectively). Urinary excretion of sodium and of chloride in response to BNP infusion was higher in patients with CHF than in control subjects (p less than 0.01, respectively). BNP infusion increased the levels of plasma atrial natriuretic peptide (control, from 65 +/- 11 to 84 +/- 14 pg/ml; CHF, from 262 +/- 65 to 301 +/- 62 pg/ml; p less than 0.05, respectively) and decreased plasma aldosterone concentrations in both groups (control, from 43.3 +/- 12.1 to 27.3 +/- 7.1 pg/ml; CHF, from 91.1 +/- 34.3 to 66.3 +/- 27.2 pg/ml; p less than 0.05, respectively). CONCLUSIONS: We conclude that BNP infusion improves left ventricular function in patients with CHF by vasodilation and prominent natriuretic action.

Female↗

PubMed1991

Nicorandil (2-nicotinamidoethyl nitrate) inhibits both vaso-dilating and -constricting effects of endothelin in a vascularly isolated hind-limb preparation in rats.

Effects of nicorandil (2-nicotinamidoethyl nitrate), a nitrate derivative with a K+ channel-opening action, on endothelin-1 (ET)-induced effects on peripheral blood vessels were studied using a hind-limb perfusion preparation in rats. ET injected into this circuit increased the perfusion pressure for more than 30 min following a transient, initial vasodepression of the perfusion system. The magnitude of both responses was dose-dependent. Pretreatments with nicorandil infused into this preparation significantly attenuated both the initial vasodilation and the sustained vasoconstriction caused by ET. The initial vasodepression caused by ET could be mediated by the release of endothelium-derived relaxing factor (EDRF). The sustained phase would be due to increased intracellular calcium elicited by ET. Nicorandil inhibited both the initial and the sustained phase of the ET-responses, probably by inhibition of intracellular phosphoinositide metabolism in both endothelium and vascular smooth muscle cells.

Analysis of Variance↗

PubMed1991

Identification and characterization of a plaque forming avian rotavirus isolated from a wild bird in Japan.

From fresh faeces of a wild bird (Melanitta fusca), a virus that showed granular cytopathic effects (CPE) on chicken kidney cell (CKC) cultures was isolated. By indirect immunofluorescence analyses (IFA), this isolate reacted with an antiserum against a bovine rotavirus. The isolate produced clear plaques on CKC by conventional techniques, without trypsin. Three virus plaques were selected by plaque size (small, medium, and large) and cloned by three successive plaque cloning. In the SDS-PAGE analyses, dsRNA bands showed a typical profile of avian rotavirus and quite different from that of avian reovirus. With dsRNA patterns, IFA results, CPE, and a morphological property, the clones were identified as avian rotaviruses of group A rotavirus. The clones killed chicken embryos, when they were inoculated to yolk sac.

Animals↗

PubMed1991

Mechanism of thyroid stimulation by human chorionic gonadotropin in sera of normal pregnant women.

To elucidate the mechanism of thyrotropic activity of human chorionic gonadotropin in sera of normal pregnant women, we examined the effect of blockade of the TSH receptor on the serum-induced cAMP accumulation and the effect of hCG on the TSH binding to FRTL-5 cells. In the presence of crude immunoglobulin fractions in sera from patients with primary hypothyroidism, cAMP accumulation induced by both crude and purified hCG, and normal pregnant women serum were significantly inhibited compared with that in the presence of normal IgGs. The mode of inhibition of these IgGs on the cAMP accumulation was similar for TSH and hCG when analysed by Lineweaver-Burk plots. Moreover, binding of [125I]bTSH to the TSH receptor in porcine thyroid cell membrane was apparently inhibited by adding 4 x 10(6) IU/l of purified hCG. Binding studies of TSH in FRTL-5 cells also indicated the dose-dependent displacements of [125I]TSH by hCG. Although half-maximal inhibitory concentration of hCG was about 20 times as high as that of TSH on a molar basis, displacement of [125I]TSH was observed at a concentration of hCG of 10(5)IU/l or more, which could be a physiological concentration of hCG in sera of normal pregnant women. These results suggest that thyrotropic activity of hCG in sera of normal pregnant women is, at least in a part, mediated by TSH receptors.

Animals↗

PubMed1991

Control of growth and differentiation of the mammary gland by growth factors.

Mammary gland development is a complex process regulated by various steroid and polypeptide hormones. Although the systemic importance of hormones, such as estrogen, progesterone, prolactin, and growth hormone, in the growth of the mammary gland has been well documented, these hormones are virtually incapable of stimulating mammary cell growth in vitro. Thus, the growth stimuli for mammary cells requires clarification. In recent years, a number of growth factors have been discovered; this has prompted interest in examining possible involvement of these biologically active agents in the process of mammary gland development. Results presented herein indicate that several growth factors including epidermal growth factor, transforming growth factor alpha and beta, basic fibroblast growth factor, insulin-like growth factor-I, and mesenchyme-derived growth factor participate in the regulation of mammary cell growth and differentiation.

Animals↗

PubMed1991

[Small sized non-small cell lung cancer in advanced stage].

Eighteen cases of non-small cell, small sized advanced lung cancer, out of 362 operated cases for 6 years excluding 7 cases of small cell lung cancer, 60 of preoperative treated and 27 of inoperable cases, were discussed. A small sized tumor was defined as a tumor within 8,000 mm3 in its volume, calculated by multipling three lengths measured on the resected specimens. There were fourteen cases with stage 3 and 4 (A), and four cases with N1 disease (B). In group A, three cases of twelve with N2 diseases showed the tiny skipping lesion in the mediastinum with negative regional nodes. Remaining two had a lesion of dissemination and pulmonary metastasis. In group B, they showed unusual way of N1 spread, in which two of them with left upper lobectomy had metastatic lymph nodes on the non-bearing lobe, the lower lobe, and other two cases took regional lymph nodes metastasis without invasive growth of the main tumor. Predominant histologic type was adenocarcinoma, but the subtype and the differentiation of it were not specific. The level of CEA was low below 5 ng/dl in most of them except three cases, in which it suggested massive positive nodes and pulmonary metastasis. Seven patients died of the disease in two years. Remainders are alive, 4 with and 7 free from the tumor with the longest period of 3 years and a half. N2 diseases of small sized tumor were found in the cases with the volume of 3 cm3 and more at almost same ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Analysis of ferritin immunostaining in testicular tumors].

Localization of ferritin in testicular tumors was studied by the immunohistochemical method and the usefulness of ferritin was evaluated compared with the clinical course. Seven cases of seminoma and 9 cases of non-seminoma were used for the study. Formalin-fixed, paraffin-embedded tissue sections were stained by the avidin-biotin complex method. Commercial rabbit anti-human ferritin polyclonal antibody in 1/100 dilution was allowed to react at room temperature for one hour. In normal testicular tissues, the epithelium in germinal cells was not stained for ferritin. In seminomas, some tumor nests were stained for ferritin. Interstitial cells, especially histiocytes, were also stained for ferritin. In stained tumor cells, cytoplasm was stained uniformly. Necrotic cells were not stained. The same findings were obtained in non-seminomas. In metastatic lesions and tumor thrombi in the vessels, some tumor cells were stained as intensely as in the origin. A case was calculated positive if more than 5% of the tumor cells in the specimen were stained. The positive rate in ferritin immunostaining was significantly higher than that of human chorionic gonadotropin (beta-HCG), alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) immunostaining with the same materials. The specimens from cases with abnormally high serum ferritin level, were stained more intensely than those from cases with normal serum ferritin level. The result suggests that ferritin might be a useful tumor marker in some of testicular tumors.

Adolescent↗

PubMed1991

Clinical effect of granulocyte colony-stimulating factor on neutrophils and leukemic cells in myelogenous leukemia: analysis.

Clinical experiences with recombinant granulocyte colony-stimulating factor (rhG-CSF) in 13 acute (AML) and four chronic (CML) myelogenous leukemia patients are reported. Sixteen patients received rhG-CSF in support of treatment for life threatening infections and one CML patient in support of induction chemotherapy. After their first induction chemotherapy, six out of eight AML patients showed a rapid increase of neutrophils, recovered from infections and achieved complete remission (CR). One patient, in whom both neutrophils and blasts had increased during rhG-CSF administration, achieved CR through the next administration of chemotherapy (CR rate 87.5%). The last of the eight AML patients showed no increase of neutrophils, and died of interstitial pneumonitis. Two of five AML patients who received rhG-CSF after reinduction chemotherapy for relapsed or refractory leukemia achieved CR, a rate of 40%. In one of the two, the administration of rhG-CSF prior to induction chemotherapy seemed advantageous in achieving CR. During rhG-CSF administration, an increase of blastic cells in peripheral blood was observed in four out of all 13 AML patients. One of three CML patients, with a lymphoid crisis, showed an increase only of neutrophils, and recovered from infection. The other two showed increases of both neutrophils and blasts. One patient with CML in blastic crisis, undergoing induction chemotherapy with rhG-CSF administration, returned to the chronic phase. These clinical experiences suggest rhG-CSF to be effective in supporting infection therapy and in possibly enhancing the sensitivity of myelogenous leukemic blasts to antileukemic agents.

Adolescent↗

PubMed1991

[The analysis of leukemic relapse after allogeneic bone marrow transplantation].

This report presents the analysis of leukemic relapse of 52 patients who received allogeneic bone marrow transplantation between July 1984 and May 1990. Conditioning regimen consisted of TBI + CY and GVHD prophylaxis consisted of cyclosporin-A and methotrexate. The relapse ratios of chronic myelogenous leukemia (CML) (21 in chronic phase, 1 in accelerated phase, 1 in blastic crisis), acute nonlymphocytic leukemia (ANLL) (all 17 in 1st CR), acute lymphocytic leukemia (ALL) (all 12 in 1st CR) were 13%, 18%, 25%, respectively, and 3 year disease free survival (DFS) was as follows, CML 68%, ANLL 72%, ALL 49%. Regarding acute GVHD grading and chronic GVHD presence, 3 year DFS was as follows, acute GVHD 0 degree: 59%, I degree: 78%, II degree-IV degree: 53%, chronic GVHD (+): 82% GVHD (-): 77%. In our center leukemic relapse has been the major cause of death after BMT since 1984. Among 9 relapsed cases, one recurred more than 3 years after BMT, and another one got recurrent leukemia of donor origin.

Adolescent↗

PubMed1991

[Effects of methylprednisolone pulse therapy on progressive IgA nephropathy].

In order to estimate the effects of methylprednisolone pulse therapy on progressive IgA nephropathy, clinical parameters in eight patients with the disease were compared between before and after the therapy. In this study progressive IgA nephropathy was defined as follows; 24 hour urinary protein excretion was (++) or more and renal biopsy carried out just before the therapy revealed crescents, inevitably including cellular crescents, in 10% or more glomeruli observed. Methylprednisolone 1000 mg a day was intravenously administered for three consecutive days and the therapy was repeated with an interval of 4 days. The additional third course was given in two patients, in whom significant decrease in urinary protein had not been obtained after the original two courses of the therapy. Oral prednisolone 20 mg a day started simultaneously was tapered one month later to maintenance daily doses of 5-10 mg. After the pulse therapy urinary protein excretion was significantly decreased in every patient with a mean decrease from 2.3 +/- 0.5 (0.8-5.5)g to 1.1 +/- 0.3 (0-2.8)g (p less than 0.05). Glomerular filtration rate (GFR) was increased from 83 +/- 11 (31-115) ml/min to 96 +/- 10 (44-130) ml/min (p less than 0.05). In the initial biopsy crescents were observed in 25 +/- 7 (19-57)% of glomeruli observed and 20-100% of these were composed of cellular crescents. Complete loss of cellular crescents in 6 patients and a marked decrease from 73% to 33% in another were demonstrated by the second biopsies performed after the pulse therapy. These results suggested that the methylprednisolone pulse therapy significantly reduced urinary protein excretion and improved renal function through suppression of new crescent formation as well as transformation of cellular crescents to fibrocellular or fibrous crescents.

Administration, Oral↗