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Biomedical subjects

M Nishimura

Publications and source records attributed to M Nishimura.

At least 559 records · Page 31Linked to original sources
PubMed1997

Performance characteristics of bilevel pressure ventilators: a lung model study.

Bilevel pressure ventilators are being used increasingly to provide noninvasive ventilatory support in the management of obstructive sleep apnea, chronic ventilatory failure, and acute respiratory failure. However, the ability of these ventilators to respond to inspiratory demand without imposing expiratory loads has not been evaluated extensively. We evaluated the performance of nine bilevel pressure ventilators in a lung model, as compared with the Nellcor Puritan-Bennett 7200ae adult critical care ventilator. All ventilators were set to provide pressure support ventilation (PSV) and positive end-expiratory pressure (PEEP) at a rate of 10 breaths/min with an inspiratory time of 1.0 s. Simulated pleural pressure, airway pressure, and flow at airway opening were continuously monitored. We studied the effects of three PSV levels (5, 10, and 15 cm H2O) with 5 cm H2O PEEP at two lung compliances (50 and 80 mL/cm H2O) and four peak inspiratory flow demands (20, 40, 60, and 80 L/min) on seven dependent variables: inspiratory delay time (D-I), inspiratory trigger pressure (P-I), inspiratory area percent (Area I%), expiratory delay time (D-E), supraplateau expiratory pressure change (P-E), expiratory area (Area E), and ventilator peak flow (VPF). Most ventilators performed as well as or significantly (p<0.05) better than the 7200ae in all studied variables. Compliance did not significantly affect ventilator performance. Increasing inspiratory flow demand significantly (p<0.05) increased D-I, P-I, P-E, and VPF and decreased Area I% with most ventilators. As ventilatory demand increased, D-E and Area E significantly (p<0.05) changed. With some units, D-E and Area E increased, while with others they decreased. Most bilevel pressure ventilators evaluated were able to respond to high ventilatory demands and outperformed the Nellcor Puritan-Bennett 7200ae ventilator.

Calibration↗
PubMed1997

[A clinical study on combination therapy of antimicrobial agents for complicated urinary tract infection--with special reference to combination with clarithromycin].

PURPOSE: To confirm the clinical efficacy of the combined therapy to complicated urinary tract infection (UTI), we conducted a comparative clinical study of the combined therapy with ciprofloxacin (CPFX) and clarithromycin (CAM) acting an biofilm elimination or CPFX alone in patients with complicated UTI. PATIENTS AND METHODS: The study was carried out in patients with complicated UTI having WBCs with 5/hpf or more in urinary sediment and bacteriuria at least 10(4) CFU/ml. The combined therapy was CPFX and CAM, each 600 mg/day, for 14 days, and the single therapy group CPFX, 600 mg/day, for 14 days. On Day 7 and 14, the eradication rate and efficacy rate (according to the criteria of the Japanese UTI committee) were determined. In the patients with indwelling catheter, the surface of the catheter tip was observed under a scanning electron microscope (SEM) on Day 14. RESULTS: In both cases with and without catheters, clinical efficacy was higher in the combined therapy group than in the single therapy group. In particular, the efficacy rates at 14 Day were significantly higher in the former group. Furthermore, we investigated the therapeutic effect in the below MIC breakpoint of CPFX in complicated UTI. The combined therapy group showed a higher clinical efficacy in both cases with and without indwelling catheter than the single therapy group, although there was not statistically significant. Biofilm on the surface of the catheter tip was eliminated in 75% of the combined therapy group. However, none of the biofilm was eliminated in the single therapy group. CONCLUSION: From the above results, we surmise that the combined use of CPFX and CAM will show some degree of efficacy in eliminating both the causative organism and its biofilm in the complicated UTI.

Adult↗
PubMed1997

[Is reduced left ventricular volume related to mechanisms of dynamic mid-ventricular obstruction provoked by dobutamine infusion?].

Forty-seven patients with unexplained chest pain and normal resting echocardiograms were examined to see whether dynamic mid-ventricular obstruction (MVO) is induced by dobutamine infusion. Dynamic MVO was provoked in 17 patients (MVO group), but not in the other 30 patients (Non-MVO group). Before dobutamine infusion, the blood pressure in the MVO group was higher than that in the Non-MVO group (p < 0.05), but end-diastolic volume index (p < 0.001), end-systolic volume index (p < 0.01), stroke volume index (p < 0.001), cardiac index (p < 0.001), end-diastolic volume (p < 0.01) and end-systolic volume (p < 0.05) of the apical territory of the left ventricle in the MVO group were significantly less than those in the Non-MVO group. The left atrial function, left ventricular ejection fraction and ejection fraction of the apical territory of the left ventricle did not differ between the groups. Seven patients in the MVO group were re-examined by dobutamine stress echocardiography after beta-blocker administration, showing that the dynamic MVO was completely suppressed. The end-diastolic volume tended to increase after beta-blocker administration, but no significant difference was found in any other variables except heart rate. The results suggest that a smaller left ventricle and higher blood pressure are important characteristics in patients with dobutamine-induced dynamic MVO, and additionally, the difference in local myocardial contractility may be an important cause of the induction of dynamic MVO.

Adrenergic beta-Agonists↗
PubMed1997

Cardiovascular regulation by L-arginine in the brain of rats: role of the brain renin-angiotensin system and nitric oxide.

The effect of brain L-arginine on arterial pressure was investigated by injecting L- or D-arginine into the cerebral ventricles of male Wistar rats that were anesthetized with urethane. Intracerebroventricular (I.C.V.) injection of 1 micromol L-arginine reduced the arterial pressure and the abdominal sympathetic nervous activity (SNA), whereas the injection of 10 micromol L-arginine induced a transient pressor response and reduced both the heart rate and SNA. Although I.C.V. injection of 1 micromol D-arginine had no effect on cardiovascular function or SNA, injection of 10 micromol of this enantiomer elicited a transient pressor response, similar to that induced by 10 micromol L-arginine, followed by a persistent increase in arterial pressure and a corresponding increase in SNA. I.C.V. pretreatment with the nitric oxide synthase inhibitor N(G)-monomethyl L-arginine abolished the vasodepressor response and reduced the inhibition of SNA induced by I.C.V. injection of 1 micromol L-arginine; such pretreatment increased the arterial pressure, heart rate, and SNA measured 30 min after I.C.V. injection of 10 micromol L-arginine. I.C.V. pretreatment with the angiotensin II type 1 receptor antagonist CV-11974 inhibited the pressor response to 10 micromol L-arginine and the first phase of the pressor response to 10 micromol D-arginine. Intravenous pretreatment with the alpha1-adrenoceptor blocker bunazosin hydrochloride abolished the pressor response to 10 micromol L-arginine and both phases of the pressor response to 10 micromol D-arginine. Brain L-arginine thus appears to exert pressor actions through stimulation of the brain renin-angiotensin system and peripheral SNA. However, these actions may be attenuated by L-arginine-derived nitric oxide.

Animals↗
PubMed1997

Intravascular lymphomatosis diagnosed by transbronchial lung biopsy.

Intravascular lymphomatosis is a rare lymphoma presenting a variety of symptoms due to proliferation of tumour cells within blood vessels in the brain, the skin and other organs. This disease is generally considered to be highly malignant, but to be relatively susceptible to combined chemotherapy, when diagnosed in the early stage. We describe a case of intravascular lymphomatosis, presenting with diffuse interstitial shadows on chest radiographic image, which could be diagnosed by transbronchial lung biopsy. The patient showed a good response to combined chemotherapy. We propose that transbronchial lung biopsy is a useful procedure for the diagnosis of intravascular lymphomatosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[Type III procollagen N-peptide and hyaluronate in serum and dialysate of CAPD patients].

Long-term CAPD may develop peritoneal fibrosis, which is thought to be related to permanent loss of ultrafiltration capacity and sclerosing peritonitis. In CAPD patients, we examined the serum (P-) and effluent (D-) levels of type III procollagen N-peptide (P III P) and hyaluronate (HA), which are expected to change concomitantly with a local increase in submesothelial extracellular matrix of the peritoneum. We selected 40 CAPD patients (age: 46.3 +/- 11.3 years, time on CAPD: 33.6 +/- 26.2 months), who were not suffering from chronic liver disease, any inflammatory disease, nor peritonitis during the previous month. P-P III P, P-HA, D-P III P, and D-HA were measured by PET (values after 4-hour dwelling). D/P ratios (P III P 0.330 +/- 0.137, HA 5.68 +/- 6.44) suggested that their source was from the peritoneum. Although neither P-P III P nor log P-HA value had a significant correlation with age nor time on CAPD, both had significantly positive correlations (p = 0.0009, 0.0005, respectively) with time on total dialysis (including hemodialysis). D-P III P did not have a significant correlation with age nor time on total dialysis but had a significantly positive correlation (p = 0.0098) with D/P-creatinine. Although log D-HA had significantly positive correlations with time on CAPD and time on total dialysis (p = 0.0007, 0.0051, respectively), time on CAPD was first entered (F = 16.5) and time on total dialysis was removed (F to enter: 4) by stepwise regression analysis. In conclusion, a local increase in extracellular matrix of the peritoneum in CAPD patients, indicated by increases in P III P and HA in the effluent, may be related to higher peritoneal permeability and a longer duration of PD.

Adult↗
PubMed1997

[A case of primary antiphospholipid antibody syndrome with severe nephrotic syndrome showing remarkable endothelial cell damage in the capillary lumen].

A 25-year-old woman complained of anasarca and was admitted to Sakura National hospital on the presumptive diagnosis of nephrotic syndrome with 10.7 g of 24-hour urinary protein. At first, lupus nephritis with antiphospholipid antibody syndrome was suspected because of prolongation of APTT, existence of lupus anticoagulant and elevation of serum anticardiolipin antibody titer (IgM) in addition to positive ANA, lymphocytopenia and the biologically false positive test for syphilis (BFPTS). On day 28 of hospitalization, renal biopsy findings revealed severe endocapillary cell damage, such as swelling and proliferation of endothelial cells, fragmentation and double contour of the basement membrane walls, which were located only in the capillary lumens with a few thrombi. Immunofluorescent micrography revealed the absence of specific immunoglobulin or complement deposit. Therefore, the diagnosis of lupus nephritis was negated as these findings were suggestive of characteristic glomerulopathy due to primary antiphospholipid antibody syndrome. She was treated initially with oral prednisolone 60 mg and intravenous infusion of heparin 20,000 units daily. Moreover, cyclophosphamide 750 mg was administered intravenously as pulse therapy on day 13 as her serum level of CH50 had fallen suddenly, and hemodialysis was necessary because her renal function had deteriorated and she was suffering from cough and orthopnea with overhydratin. After the combined therapy, BFPTS disappeared and APTT returned to the normal range: dialysis treatment was not required further after the 4th hemodialysis. Thereafter, renal function improved and complete remission of nephrotic syndrome was obtained. This patient was a case of primary antiphospholipid antibody syndrome in which endothelial cell damage was located exclusively in the capillary lumens and pulse cyclophosphamide therapy in addition to prednisolone and anticoagulant was effective. We present this instructive case to promote understanding of the pathogenesis of primary antiphospholipid antibody syndrome.

Adult↗
PubMed1997

[Possible involvement of donor-derived B cells in development of post-transfusion graft-versus-host disease].

Post-transfusion graft-versus-host disease(PT-GVHD) is one of the most severe side effects of blood transfusion. To clarify the mechanism of development PT-GVHD, we characterized possible effector lymphocyte clones, presumably involved in the occurrence of PT-GVHD. By lymphocyte cloning from peripheral blood of a PT-GVHD patient, not only donor-derived cytotoxic T cell clones but also donor-derived B cell clones were established. The B cell clones produce cytotoxic IgG, directed against the patient's class II HLA. It was strongly suggested that donor-derived B cells, through production of cytotoxic IgG directed against the patient's HLA, were involved in the pathogenesis of the PT-GVHD in this case.

B-Lymphocytes↗
PubMed1997

[Serum hepatocyte growth factor as a possible indicator of vascular lesions].

To investigate the possible involvement of hepatocyte growth factor (HGF) with vascular lesions, we studied the relationship between serum HGF concentrations and the grades of retinal arteriosclerosis, coronary atherosclerosis, and the proliferative changes in the retina of diabetic subjects. Individuals with more advanced grades of arteriosclerotic change showed higher serum HGF values (grade 0, 0.056 +/- 0.004ng/ml; grade 1, 0.132 +/- 0.026ng/ml; grade 2-3, 0.271 +/- 0.023ng/ml). The serum HGF concentration was increased (p < 0.05) in subjects with double- (0.323 +/- 0.037ng/ml) or triple-(0.345 +/- 0.027ng/ml) vessel coronary heart diseases, as compared to that in subjects with single-vessel coronary heart disease (0.191 +/- 0.027ng/ml). Serum HGF in diabetics without retinopathy was lower than that in nondiabetic subjects (0.041 +/- 0.003ng/ml vs 0.080 +/- 0.010ng/ml, p < 0.05), but did not differ from other diabetic subjects with background retinopathy (0.058 +/- 0.007ng/ml) or preproliferative retinopathy (0.048 +/- 0.010ng/ml). Serum HGF was increased in proliferative retinopathy without photocoagulation (0.138 +/- 0.035ng/ml, p < 0.01), but not with photocoagulation (0.040 +/- 0.008ng/ml). Increased serum HGF may be involved in the pathogenesis of arteriosclerosis/atherosclerosis or retinal neovascularization, and measurement of serum HGF may be a useful test to predict the presence of these vascular lesions.

Arteriosclerosis↗
PubMed1997

Immunological functions of adult T cell leukemia cells of a patient complicated with synchronous double primary gynecologic cancer.

A patient with triple malignancies is reported, who presented cervical cancer, vulvar cancer and adult T cell leukemia (ATL). ATL was diagnosed as a smouldering type, because antibody to human T cell leukemia virus associated antigen (ATLA) was positive with a titer of 1:160. Although her malignant cells had an OKT 4+8-3+Tac+ phenotype, the cells did not display helper T cell functions. Namely they showed no response to Phytohemagglutinin (PHA) and Interleukin 2 (IL-2) and suppressed the PWM driven IgG synthesis of B cells obtained from healthy donor. They did not produce IL-2 by stimulation with PHA and phorbol myristate acetate (PMA). Furthermore, these ATL cells were producing IL-2 inhibitor like factors. As synchronous triple malignancies are extremely rare, two gynecologic cancers seem to ascribe to the suppressing state of the immunosurveillance mechanism by viral infection.

Aged↗
PubMed1997

[Role of tumor necrosis factor-alpha in insulin sensitivity and effect of low protein diet on the TNF-alpha response in patients with diabetic renal failure].

In patients with diabetic renal failure, attention must be paid to the prevention of atherosclerosis as well as the preservation of renal function. Insulin resistance is one of the important risk-factors of atherosclerosis and the involvement of tumor necrosis factor-alpha (TNF-alpha) has been shown in the pathogenesis of insulin resistance in some diseases. A low-protein diet (LPD) is recommended for patients with advanced renal disease, but a large proportion of the total caloric intake is supplied from carbohydrates and fat in LPD. Therefore, we designed a study to determine: (1) the effect of TNF-alpha on insulin sensitivity, and (2) the effect of LPD on the TNF-alpha response and the risk factors of atherosclerosis, such as insulin sensitivity and lipid metabolism, in patients with diabetic renal failure. Insulin sensitivity was measured by an euglycemic hyperinsulinemic clamp technique and serum TNF-alpha level and in vitro release of TNF-alpha from peripheral blood mononuclear cells (PBMCs) was measured in patients with diabetic renal failure. A significant negative correlation was observed between lipopolysaccharide-stimulated TNF-alpha release from PBMCs and insulin sensitivity (r = -0.58, p < 0.05). Secondly, risk factors of atherosclerosis were measured before and two weeks after the introduction of LPD in patients with diabetic renal failure. LPD did not have any significant effect on insulin sensitivity, the production of TNF-alpha by PBMCs, lipid metabolism and glucose metabolism. These results indicate that: (1) TNF-alpha derived from PBMCs might affect insulin sensitivity in patients with diabetic renal failure, and (2) LPD does not have any significant effect on the risk factors of atherosclerosis.

Diabetic Nephropathies↗
PubMed1997

Host modifier genes affect mouse autoimmunity induced by the lpr gene.

A defect in apoptotic signal transmission through CD95 is an essential genetic mechanism for lymphoproliferation and autoimmunities in lpr or gld mice. However, disease manifestations are largely affected by the host genetic background. To identify and map such host genes modifying lpr gene effect, ie, the lpr modifier (Lprm) genes, 82 MRL/lpr x (MRL/lpr x C3H/lpr) F1 mice were subjected to immunopathological and genetical analyses. High-grade vasculitis and glomerulonephritis among backcross mice were observed in separate groups of mice. Microsatellite analysis revealed that there were two host genes affecting the occurrence of vasculitis, Lprm1 (chromosome 4) and Lprm2 (chromosome 3). A recessive MRL allele at Lprm1 enhanced vasculitis to occur in both sexes, whereas that of Lprm2 inhibited its development selectively in females. Genotype combinations of these two genes explained the severity of vasculitis in crosses of MRL/lpr and C3H/lpr mice and also the vasculitis-prone recombinant inbred strain McH5/lpr. A recessive MRL allele at Lprm3 (chromosome 14) suppressed glomerulonephritis. The weight of the spleen was increased by a recessive MRL allele at Lprm4 (chromosome 5) yielding a logarithm of odds score of 2.02 in a quantitative trait locus analysis. In contrast, the weight of axillary lymph nodes was increased by a recessive MRL allele at a locus on chromosome 2, but its presence was not supported by the quantitative trait locus analysis. The titer of anti-dsDNA autoantibody was controlled by the locus Lprm5 on chromosome 16, which had an logarithm of odds score of 3.41. Possible candidate genes for Lprm genes deduced from their map locations are discussed and compared with the autoimmunity genes reported thus far. In conclusion, autoimmune disease manifestations by the lpr mutation are affected by multiple host genes separately.

Animals↗
PubMed1997

Augmentation rhinoplasty by subcutaneous midline forehead flap simultaneous with implant removal.

Implant exposure after augmentation rhinoplasty with alloplastic materials is usually associated with some degree of infection, and it is commonplace to remove the implant and wait for several months before re-augmentation. However, some patients cannot accept the resultant deformity after implant removal. We introduced the midline forehead flap for augmentation simultaneous to the removal and obtained favorable results, even when considering the donor site scar on the forehead. We report the surgical technique and two patients treated with this procedure. The advantages and disadvantages of this procedure are also discussed.

Aged↗
PubMed1997

Two different hard palate closure techniques in two-stage palatoplasty: effects on velopharyngeal closure and articulation.

Two different hard palate closure techniques, in two-stage palatoplasty, was evaluated in 12 patients. The lip and soft palate were closed at 3 to 7 months of age. The patients were then divided into two groups of six and the hard palate closed at 17 to 23 months of age, either by a vomer flap (VF) with a skin graft (Osada's two-stage palatoplasty) in the VF group, or by the push-back (PB) procedure of the mucoperiosteal flap in the PB group. Velopharyngeal closure (VPC) during a gag reflex before and after hard palate closure, and the articulation of these patients after closure, were evaluated and compared between the two groups. Regarding VPC before hard palate closure, three "Poor" and three "Borderline" outcomes were noted in each group. We conclude that, by introducing the pharyngeal flap, the patients in the VF group obtained good articulation, actually comparable to that in the PB group.

Articulation Disorders↗
PubMed1996

Changes in trough levels of whole blood cyclosporine and graft function of a kidney transplant recipient with onset of hypothyroidism after transplantation.

The immunosuppressive and toxic effects of cyclosporine (CsA) are affected by many factors. We present the first case of a kidney transplant patient who had an onset of hypothyroidism about two months after the transplantation. In this case, trough levels of whole blood CsA and total serum cholesterol levels increased at the same time. But the decrease in renal function was not as severe as expected from the very high trough levels of whole blood CsA. Elevation of the trough level of whole blood CsA may be due to a decrease in CsA clearance resulting from the decreased cytochrome P-450 activity in hypothyroidism. Furthermore, a decrease in thyroid hormone level and increase in plasma lipoprotein level might have affected the distribution of CsA, and this change might have influenced the toxic effect of CsA In conclusion, our case suggests that thyroid function and plasma lipoprotein level should be considered important factors that affect the pharmacokinetics and action of CsA.

Adult↗
PubMed1996

Relation between dynamic midventricular obstruction and unexplained chest pain in patients with normal echocardiograms at rest.

The relation between dynamic mid-ventricular obstruction provoked by dobutamine infusion and chest pain was investigated in 16 patients with normal echocardiograms at rest who had histories of unexplained chest pain. Chest pain was induced in 63% of dynamic mid-ventricular obstruction and beta blockers suppressed either dynamic mid-ventricular obstruction or Chest pain.

Acebutolol↗