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Biomedical subjects

M Nishimura

Publications and source records attributed to M Nishimura.

At least 1,585 records · Page 88Linked to original sources
PubMedDate not supplied

Endovascular stent graft placement for patients with aortic aneurysm and end-organ dysfunction.

Endovascular stent grafts (ESGs) for the treatment of aortic aneurysm is becoming popular because it is less invasiveness for the patient. This new modality seems to be especially useful for treating high risk patients, such as those with end-organ dysfunction. In this study we retrospectively analyzed the results of ESG placement for patients with renal or hepatic dysfunction. From January 1996 to December 1997, six patients with end-organ dysfunction (two with descending thoracic aneurysm and four with abdominal aneurysm) underwent ESG placement. Five of these patients had renal dysfunction, with serum creatinine levels of 2.0 mg/dl or greater, and the remaining patient had hepatic dysfunction with a prothrombin time less than 60%. One of the patients also had severe atherosclerotic disease with a history of multiple brain infarctions. All the patients received custom made endovascular spiral Z stents covered with a woven Dacron (DuPont Co., Wilmington, DE) graft, which was delivered via a femoral artery under local anesthesia. None of the patients showed significant changes in renal or hepatic function after the procedure. None of the five patients with renal dysfunction needed hemodialysis after ESG placement, although the mean preoperative level of serum creatinine and blood urea nitrogen was 3.4 mg/dl and 42.0 mg/ dl, respectively. All the patients left the recovery room on postoperative day 1. These results indicated that endovascular stent graft placement is extremely useful in the treatment of aortic aneurysm patients with end-organ dysfunction.

Aged↗
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P-selectin monoclonal antibody may attenuate the whole body inflammatory response induced by cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) is known to induce an inflammatory response in association with neutrophil mediated lung injury. P-Selectin has been reported to be involved in the initiation of this inflammatory response by promoting the adhesion of neutrophils to endothelial cells in postcapillary venules. However, the role of P-selectin in the inflammatory response induced by CPB has never been clarified. To elucidate its role, we evaluated the effect of an anti-rat specific P-selectin monoclonal antibody (ARP2-4; Sumitomo Pharmaceutical) on the response of inflammatory cytokines and lung injury in a rat-CPB model. Twenty Sprague-Dawley rats underwent CPB for 30 minutes (80 ml/kg per minute, 34 degrees C) under one of two conditions. In group P, ARP2-4 (3 mg/kg) was added to the priming solution of the bypass circuit (n = 10). Saline alone was given to group C (n = 10). Inflammatory cytokines (tumor necrosis factor-alpha [TNF-alpha], interleukin[IL]-1beta, IL-6, and IL-8) and respiratory index (RI) as a marker of pulmonary gas-exchange ability were measured 1) before the initiation of CPB, 2) at the termination of CPB, and 3) 2 hours after the termination of CPB. Neither TNF-alpha nor IL-1beta was detected during the experimental period in either group. The plasma levels of IL-6 and IL-8 increased after CPB in both groups, but they were significantly lower in group P than in group C. The RI value increased in a pattern similar to that of the inflammatory cytokines and was significantly lower in group P. These data demonstrate that the addition of an anti-rat specific monoclonal antibody inhibits the abnormal release of inflammatory cytokines and attenuates CPB induced lung injury in rats. Thus, P-selectin may play a role in the augmentation of CPB induced inflammatory response, and the use of its inhibitory monoclonal antibody seems to be a promising strategy for the treatment of CPB induced lung injury.

Animals↗
PubMedDate not supplied

Thymoma with osseous metaplasia.

A 69-year-old woman with a 15-year history of abnormal chest shadow was referred to our hospital. An enhanced chest CT scan of the anterior mediastinum revealed a mass containing a high-density area. The preoperative radiologic diagnosis was thymoma. Operation was performed in October 2000. Histologically, multiple ossified areas were observed within the tumor. Intratumoral ossification has never been reported in thymoma. Therefore, we report the first case of thymoma associated with multiple foci of osseous metaplasia.

Aged↗
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Membrane action of ethmozin on normoxic and hypoxic canine Purkinje fibers.

Transmembrane potentials were recorded from canine Purkinje fiber preparations before and after perfusion with ethmozin (0.05, 0.2, and 1.0 microgram/ml). Under normal oxygenation (95% O2 + 5% CO2; n = 9), ethmozin at 0.05 microgram/ml significantly (p less than 0.05) reduced maximal rate of depolarization (MRD), from 750 +/- 61 to 709 +/- 58 V/s, without affecting other parameters. MRD was further decreased to 647 +/- 53 and 540 +/- 78 V/s at 0.2 and 1.0 microgram/ml of this agent. Reduction of maximal diastolic potential, from -86.1 +/- 6.0 to -84.6 +/- 5.9 mV, occurred only at 1.0 microgram/ml, suggesting that the decrease in MRD is not voltage dependent. Ethmozin significantly shortened the action potential duration at 50 (APD50) and 90% (APD90) repolarization, from 231 +/- 16 and 306 +/- 18 to 199 +/- 26 and 279 +/- 14 ms, respectively. At 1.0 microgram/ml, these values were further reduced. The effective refractory period also showed a concentration-dependent shortening, but the ratio of the refractory period to APD90 was increased. The membrane responsiveness curve was shifted by ethmozin to more negative potentials. The h infinity (inactivation of the fast Na+ current) curve was shifted by 3.8 mV to more negative values by 1.0 microgram/ml ethmozin. "Slow response" produced by high K+ + isoproterenol (0.025 microgram/ml) was not affected by ethmozin (1.0 and 5.0 microgram/ml). Ethmozin exaggerated the electrophysiologic effects of hypoxia (95% N2 + 5% CO2; n = 6).(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMedDate not supplied

Electrophysiologic actions of dibenzepin, a tricyclic antidepressant, on canine Purkinje fibers.

Electrophysiologic effects of dibenzepin, a tricyclic antidepressant drug known experimentally to defibrillate the ventricles, were studied in canine Purkinje fibers with glass microelectrodes. In 11 normally perfused preparations the dose-response curve (10(-8)-10(-5) g/ml) revealed that the threshold concentration of this drug was 10(-7) g/ml, reducing the maximal rate of depolarization (MRD) from 930 to 876 V/s and overshoot from 32 to 30 mV, respectively (p less than 0.05). At 10(-6) g/ml, dibenzepin shortened action potential duration (APD) at 50 and 90% repolarization (APD50, APD90), respectively, from 290 to 248 ms and from 385 to 363 ms (p less than 0.001). At 10(-5) g/ml, it decreased the maximal diastolic potential (MDP) from -92 to -85 mV and further reduced MRD, overshoot and APD50 (p less than 0.01). The membrane responsiveness curve was shifted to more negative potentials, but its normalized curve (h infinity curve) remained unchanged. This drug did not alter slow response action potentials produced by 22 mM K+ and 10(-7) M isoproterenol. In six Purkinje fibers, hypoxia (100% N2) reduced MDP and MRD. Subsequent addition of dibenzepin further decreased MRD and shortened APD50. These results indicate that (a) dibezepin inhibits the fast Na+ current without changing its inactivation kinetics, thus suggesting a class 1 antiarrhythmic action; (b) it does not affect the slow inward current; and (c) the former action appears enhanced during hypoxia, possibly contributing to ventricular defibrillation.

Action Potentials↗
PubMedDate not supplied

Bacteriologic studies on Neisseria gonorrhoeae isolated in Sapporo, Japan: investigation of beta-lactamase production and auxotypes.

The authors studied the annual incidence of isolation of penicillinase-producing Neisseria gonorrhoeae (PPNG) strains among the total number of strains of N. gonorrhoeae (1,401 strains) that were isolated in Sapporo, Japan during 1980-1989. During the first half of the 1980s, there was a tendency for PPNG to increase, and the peak incidence was 23.9% in 1985. Thereafter, the incidence of PPNG decreased to an isolation rate of 6.3% in 1989. In addition, the auxotypes of 592 of 1,401 isolated strains of Neisseria gonorrhoeae were studied during three periods: 1980-1985, 1986-1987, and 1988-1989. Among the 592 strains, 315 strains were tested for sensitivity to the action of amoxicillin. In the 1988-1989 period, the auxotype showed an increasing incidence of the auxotype that requires arginine, hypoxanthine, and uracil (i.e., AHU), whereas the proto- and pro-types decreased in incidence. The AHU strains showed higher sensitivity to amoxicillin administration compared with the proto- and pro-strains.

Amoxicillin↗
PubMedDate not supplied

Epidemiologic study of Chlamydia trachomatis infection in pregnant women.

GOAL OF THE STUDY: The presence of Chlamydia trachomatis in the cervical canal was investigated in 10,980 married pregnant women and 1,792 unmarried pregnant women who underwent artificial abortions in Hokkaido. STUDY DESIGN: Cervical canal smears were screened for C. trachomatis in pregnant patients. RESULTS: In the married women, the detection rate of C. trachomatis was 5.6% (615 of 10,980 cases). In the unmarried women, the detection rate of C. trachomatis was 15.2% (272 of 1,792 cases). Stratification of the data on the detection of C. trachomatis as a function of the subjects' age showed that, for both the married and the unmarried women, the detection rate increased as the age of the subjects decreased. Analysis of the detection rate of C. trachomatis as a function of the year revealed that it had not changed since 1986. CONCLUSIONS: The findings in this study show that there has been an epidemic of asymptomatic C. trachomatis infections in Hokkaido, especially in young women.

Adult↗
PubMedDate not supplied

Neoadjuvant chemotherapy with cisplatin, aclacinomycin A, and mitomycin C for cervical adenocarcinoma--a preliminary study.

Between 1989 and 2002, 28 patients with locally advanced cervical adenocarcinoma (bulky IB-IIIB) were recruited for a pilot study aimed at evaluation of the effectiveness of neoadjuvant chemotherapy with cisplatin, aclacinomycin-A, and mitomycin-C (PAM), followed by radical surgery. This regimen was administrated intra-arterially or intravenously. In addition to patients treated with PAM, we retrospectively analyzed the prognoses of 26 patients in stage I and II, who had been treated between 1975 and 1981 with radical surgery with/without radiation therapy. Twenty-eight patients received PAM therapy as neoadjuvant chemotherapy, and 75.0% of the 16 intra-arterially infused patients showed a response, as did 66.7% of the 12 intravenously infused patients. There was a significant difference in the 5-year prognosis of stage II (PAM group, 72.9%; without-PAM group, 36.4%). The results suggest that, as the free space in the parametrium is widened by neoadjuvant chemotherapy with PAM, it is possible that the tumor could be completely resected by radical hysterectomy. Thus, neoadjuvant chemotherapy with PAM is expected to improve the survival rate of patients with advanced cervical adenocarcinoma by the preliminary study. However, the survival rates of stage II with lymph node metastasis in the without-PAM group seem low, and we must also consider that the various technologies to evaluate and treat the cervical adenocarcinomas, e.g. computed tomography, magnetic resonance imaging, and surgical equipments, had improved during 1989-2002 than was the scenario during 1975-1981, and these improvements contributed to better prognosis. A prospective-randomized study is needed to assess the value of this approach compared with standard management.

Aclarubicin↗
PubMedDate not supplied

Balanitis of Zoon.

A patient with an eruption of clinical and histologic features typical of plasma cell orificial mucositis of the glans penis is reported. Immunohistologically, IgE and IgG are found to be major immunoglobulin classes in the plasma cellular infiltrate. Although specific allergen has not been identified yet, the present findings suggest that this condition is not a nonspecific inflammatory response but is related to immediate hypersensitivity.

Aged↗
PubMedDate not supplied

Bactericidal effect of levofloxacin on strains with equal susceptibility in an in vitro urinary bladder model.

The in vitro bactericidal effects of therapeutic concentrations of levofloxacin (LVFX) on clinical isolates of Pseudomonas aeruginosa and Enterococcus faecalis were assessed. Starting from 10(7) CFU/ml, the bacterial count was determined serially during the exposure to LVFX present at concentrations automatically simulated to its clinically achievable urinary levels at the recommended dosage (100 mg 3 times daily). An isolate of P. aeruginosa for which the MIC of LVFX was 16 microgram/ml was completely eradicated after 10 h of exposure to LVFX. On the other hand, 40 h of exposure to LVFX were required for complete eradication of an isolate of E. faecalis with equal susceptibility, although the bacterial count was rapidly reduced to 10(2) CFU/ml in the early phase of the exposure. It was concluded that LVFX exerts a more potent bactericidal effect on P. aeruginosa than on E. faecalis despite a similar susceptibility of these organisms to LVFX.

Anti-Infective Agents, Urinary↗
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Bactericidal activity of gatifloxacin (AM-1155) against Pseudomonas aeruginosa and Enterococcus faecalis in an in vitro bladder model simulating human urinary concentrations after oral administration.

The bactericidal activity of gatifloxacin, a new 6-fluoro-8-methoxy quinolone, was determined in a dynamic in vitro model mimicking complicated lower urinary tract infection. Strains of Pseudomonas aeruginosa and Enterococcus faecalis with different susceptibility were exposed to changing gatifloxacin concentrations, simulating human urinary concentrations afer oral treatment with 200 mg twice daily for 3 consecutive days. Bacterial numbers of P. aeruginosa (minimal inhibitory concentrations, MIC: < or =32 microg/ml) and of E. faecalis (MIC: 16 microg/ml) were reduced to undetectable levels during exposure. For the strains with lower susceptibility, gatifloxacin showed bactericidal activity, but eradication was not complete. Thus, in a complicated urinary tract infection model, breakpoint MICs of gatifloxacin for uropathogenic organisms were presumed to range from 16 to 32 microg/ml. At least 86% of recent clinical isolates of P. aeruginosa and E. faecalis were inhibited at its breakpoint MIC. These results suggest that gatifloxacin may be useful in the treatment of urinary tract infections.

Administration, Oral↗
PubMedDate not supplied

Changes in susceptibility of Pseudomonas aeruginosa to gatifloxacin and carbapenem in an in vitro urinary bladder model.

To study the changes of bacterial susceptibility during exposure to antimicrobials, the respective minimal inhibitory concentrations (MICs) of 50 colonies from each of various bacterial test strains were determined in an experimental system using an in vitro urinary bladder model. The MICs of gatifloxacin and meropenem for Pseudomonas aeruginosa strains were not homogeneous before exposure to the drugs. The MICs of the strains examined reflected only that of their dominant population. When starting from 10(7)CFU/ml, the bacterial count was determined serially during exposure to gatifloxacin or meropenem in therapeutic urinary concentrations. The MIC of the less susceptible population of each strain was changed serially to a higher one. The more susceptible strains were eradicated before the change of the MIC. The bacteria originally consisted of strains having heterogeneous susceptibility to drugs, in which major strains had susceptibility expressed by the MIC and minor ones had a higher or lower MIC. This heterogeneity may be responsible for the change of susceptibility in strains after exposure to the drugs.

Anti-Infective Agents↗
PubMedDate not supplied

Systemic inflammatory response syndrome and acute renal failure associated with Hemophilus influenzae septic meningitis.

Sepsis is often associated with a downward spiral through a spectrum of systemic inflammatory response syndrome (SIRS) culminating in organ failure and death. Here we present a 3-year-old girl with Hemophilus influenzae septic meningitis who developed SIRS and acute renal failure. In the initial stage, the patient showed uremia, cytopenia, disseminated intravascular coagulation, elevation of tissue enzyme and ferritin values, hemophagocytosis and overproduction of nitric oxide. The serum cytokine profile revealed increased levels of soluble interleukin (IL)-2 receptor, IL-6, IL-10 and tumor necrosis factor alpha. The patient responded positively to early and intensive interventions including antibiotics, repeated exchange transfusions, dexamethasone and high-dose gamma-globulin. The above laboratory abnormalities almost normalized with clinical improvement. We consider that SIRS was probably responsible for the sequence of events resulting in renal failure in this case, and suggest that renal failure should be included among the serious complications of SIRS associated with Hemophilus influenzae septic meningitis.

Acute Kidney Injury↗
PubMedDate not supplied

Nuclear pseudoinclusions in angiomyolipoma of the kidney. A case report.

BACKGROUND: Fine needle biopsy has been utilized for the preoperative diagnosis of angiomyolipoma of the kidney. However, the spectrum of diverse nuclear morphology shown by the constituent smooth muscle cells of angiomyolipoma has not been fully elucidated. CASES: An angiomyolipoma was found incidentally in the left kidney of an asymptomatic, 57-year-old woman, and nephrectomy was performed. The tumor was composed predominantly of smooth muscle cells occasionally showing atypical nuclear features. Small aggregates of adipocytes were also found. Direct stamp specimens of the tumor revealed plump, spindle-shaped smooth muscle cells, and the nuclei of many of these cells contained large pseudoinclusions (cytoplasmic invaginations). Histologic review of an additional four cases of renal angiomyolipoma further revealed the frequent occurrence of nuclear pseudoinclusions in smooth muscle cells of the tumor. CONCLUSION: Nuclear pseudoinclusions on fine needle aspiration cytology of renal angiomyolipoma have not received adequate attention. We showed that this finding is a rather common nuclear feature in angiomyolipoma. It is presumably one of the manifestations of nuclear pleomorphism frequently seen in smooth muscle cells of angiomyolipoma and should not be considered an indication of malignancy.

Angiomyolipoma↗
PubMedDate not supplied

Pentobarbital protection from cerebral infarction without suppression of edema.

We studied the mechanism of barbiturate protection from focal cerebral infarction in cats by examining in detail edema formation 72 hours after acute, permanent occlusion of the left middle cerebral artery (LMCA). Neurological function, gas exchange, vital signs, and intracranial pressure (ICP) were observed during the post-occlusion period, and infarct size and cerebral edema were measured after sacrifice. Infarct size was reduced only when pentobarbital was given before occlusion and continued for 24 hours. Edema formation was not suppressed even though the extent of infarction was. Clinical evidence of stroke developed and ICP rose in most cats after occlusion despite the presence of pentobarbital sufficient to reduce infarct size. Elevated ICP accounted for most premature deaths despite intensive cardiopulmonary support. Water and electrolyte changes in the ischemic hemisphere continued to develop throughout the 72 hour post-occlusion period in pentobarbital-treated cats, suggesting that resolution of edema was delayed by the drug. We conclude that pentobarbital reduces infarct size and attenuates the expected time course of ischemic edema in cats, but that the drug has little effect on the severity of edema that develops after arterial occlusion.

Animals↗
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Clofibrate-induced myopathy in a patient with primary hypothyroidism.

Acute muscle pain with stiffness developed in a patient with latent hypothyroidism after administration of clofibrate. Serum creatine kinase (CK), aspartate aminotransferase, and lactate dehydrogenase were markedly elevated, but returned to normal one and a half months after the discontinuation of clofibrate. Clofibrate challenge (750 mg/day) for three days caused muscle pain and an elevation in serum CK. Hypothyroidism may be a predisposing factor in the development of clofibrate-induced myopathy.

Adult↗
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Nephropathy of nail-patella syndrome.

Ultrastructural renal lesions of a sporadic case of nail-patella syndrome are described. Although the patient, an 8-year-old Japanese boy, had no clinical renal syndrome, electron microscopy disclosed the presence of collagen fibrils and electron lucent areas within glomerular basement membrane. Comparative observation of glomeruli in sections stained by uranyl-acetate and lead-citrate and those by PTAH-uranyl revealed evidence of many collagen fibrils in mesangial matrix, as well as glomerular basement membrane. At the follow-up study 3 years after the biopsy, he still showed normal urinalysis and no renal dysfunction. Characteristic ultrastructure of glomerulus of this disease can be present even in cases without any apparent clinical renal involvement. It is concluded that the glomerular lesions in nail-patella syndrome may be caused by abnormal metabolic processes of collagen in glomeruli rather than entrapment of circulating collagen precursors.

Basement Membrane↗