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Biomedical subjects

S Nishi

Publications and source records attributed to S Nishi.

At least 19 recordsLinked to original sources
PubMed1999

Selection effects on an estimation of long-term changes in pulmonary function.

To reveal the association of initial pulmonary function level with subsequent mortality and participation in a follow-up reexamination, a prospective cohort study was performed. Female residents in a volcanic area of southern Kyushu, Japan, were followed up for their vital status and the pulmonary function 15 years after they received the first pulmonary function test. A cohort of 512 Japanese female residents who were examined for pulmonary function as indicated by forced expiratory volume and forced expiratory volume in one second was measured in a baseline examination in 1980. After 15 years, 35 females were lost to follow-up. Of the remaining 477 females, 340 and 137 females provided good and poor levels of pulmonary function tests (PFT) at baseline, respectively. Mortality by 1995 in the poor PFT group was significantly higher than that in the good PFT group (33.6% vs 9.4%). The mortality differences were still highly significant when the 35 lost cases were included as all alive. Among the 399 survivors, the nonparticipation rate in the reexamination in 1995 was significantly higher in the poor PFT group than that in the good PFT group (80.2% vs 69.5%). The results of the present study, a longitudinal study of pulmonary function, provide evidence of selection effects due to death or failure to participate in a subsequent reexamination.

Adult↗
PubMed1999

Endovascular treatment of aneurysms on the feeding arteries of intracranial arteriovenous malformations.

The association between intracranial aneurysms and arteriovenous malformations (AVMs) is well documented. Recent advances in the understanding of the haemodynamics of this association encourage an aggressive approach to these aneurysms. However, the pathophysiology of these aneurysms is not fully understood and a strategy for their management has not been established. We describe seven patients, with eight aneurysms, on the feeding arteries of AVMs. The aneurysms could be divided into those located 1. proximally on the superficial feeding artery (type I; 4 aneurysms); 2. distally on the superficial feeding artery (type II; 3 aneurysms); and 3. on the deep feeding artery (type III; 1 aneurysm). All aneurysms were treated by the endovascular procedure prior to, or simultaneously with, treatment of the AVM, using detachable coils or liquid embolic material. All aneurysms were obliterated successfully, with no adverse events. Each patient further received treatment of the AVM. None of the patients suffered intracranial haemorrhage after treatment for the aneurysms. Based on our experiences, we discuss the indications for this approach for each type of aneurysm. We believe endovascular treatment could be an important alternative for treatment of aneurysms associated with AVMs, thus reducing the risk of haemorrhage.

Adult↗
PubMed1999

Determination of potassium flux activity of viable human erythrocytes by measuring the release-influx ratio.

A simple and convenient method to determine the K+-flux activity of viable human erythrocytes was developed. Erythrocyte suspensions were incubated at 4 degrees C for 24 h to induce K+-release (deltaKr) and then at 37 degrees C for 3 h to influx K+ into erythrocytes (deltaKi). A straight-line relationship between K+ release-influx ratio and ouabain-induced K+-efflux from erythrocytes indicated that deltaKi/deltaKr ratio or the K+-flux activity was reflected predominantly by Na+/K+-exchanging ATPase activity. Using this method, K+-flux activity of erythrocytes in the young and the aged subjects was measured. The mean deltaKi/deltaKr ratio of the aged subjects was decreased significantly. This method of measuring deltaKi/deltaKr ratio is useful for the evaluation of K+-flux activity of viable erythrocytes.

Adolescent↗
PubMed1999

Cosmetic osteoplastic craniotomy with a chisel and hammer.

BACKGROUND: Osteoplastic craniotomy has been performed recently with microfixation systems such as miniplates, burr hole buttons, and/or ceramic dust. However, these are costly methods of treatment. Without the use of these devices, we performed cosmetic osteoplastic craniotomy using an inexpensive chisel and hammer. METHODS: Our osteoplastic craniotomy with a chisel and hammer was used on 19 lesions in 15 patients. Using a chisel, the bone flap was cut gently from the calvarium to the skull base, the lamina externa to the diploe (finally the lamina interna), and both ends to the midportion between two holes. The lamina interna in the cranium was trimmed easily after removal of the bone flap. The bone defect was minimal because of the absence of a narrow cutting groove and because craniectomy was not performed. The bone flap was replaced by tapping and was tightly fixed. No special fixation system was needed, except for threads. RESULTS: Follow-up (mean follow-up, 5 months; range, 5 weeks to 9 months) skull X-ray and 3D-CT showed good fusion and inherent normal configuration of the bone flap. There were two minor dural tears and two minor bony fractures. CONCLUSION: A good cosmetic effect without the use of any additional instruments was accomplished with osteoplastic craniotomy using a chisel and hammer.

Craniotomy↗
PubMed1999

Lipoprotein(a) is a predictor for cardiovascular mortality of hemodialysis patients.

BACKGROUND: Although hemodialysis (HD) patients have been associated with elevations in serum lipoprotein(a) [Lp(a)] levels, relatively little has been published on the link between Lp(a) and the risk for atherosclerotic cardiovascular death in HD patients. METHODS: Lipoprotein(a) was measured in 390 HD patients. The relationship between Lp(a) and mortality (overall and cardiovascular) was determined during 28 months of prospective follow-up. RESULTS: Hemodialysis patients demonstrated Lp(a) concentrations that were approximately two times as high as that of healthy controls (median, 16 vs. 8 mg/dl, P < 0.001; mean, 22.9 vs. 12.1 mg/dl, P < 0.01). Lp(a) showed a significant correlation between albumin, total cholesterol, low-density lipoprotein cholesterol, and C-reactive protein. The high-Lp(a) group [Lp(a) > or = 30 mg/dl] showed significantly higher mortality than the low-Lp(a) group [Lp(a) < 30 mg/dl] in a Kaplan-Meier survival analysis (P < 0.05). Multiple logistic regression analysis demonstrated albumin, age, and diabetic state as significant risk factors for overall death. However, if confined to atherosclerotic cardiovascular death, Lp(a) (P < 0.01), age, and diabetic state were the only independent contributors. CONCLUSIONS: Lp(a) is an independent risk factor for atherosclerotic cardiovascular death in Japanese patients receiving chronic dialysis therapy.

Age Factors↗
PubMed1999

Existence of human DAZLA protein in the cytoplasm of human oocytes.

The human deleted in azoospermia-like autosomal (DAZLA) gene is thought to be a candidate gene for azoospermia. cDNA encoding the C-terminal 94 amino acid residues of human DAZLA was used to express a bacterial fusion protein which was then used to raise polyclonal antibodies in rabbits. Immunohistochemical analyses with the human DAZLA antiserum showed that the DAZLA protein is expressed at a cytoplasmic location in female germ cells. Available evidence suggests that the DAZLA gene is a participant in human oogenesis.

Adolescent↗
PubMed1999

Expression of the molecule detectable by anti-propolypeptide of von Willebrand factor antibody in rat mesangial cells in anti-Thy 1.1 mAb 1-22-3 induced glomerulonephritis: A marker of injured mesangial cells.

We have previously reported that propolypeptide of von Willebrand factor (pp-vWF) binds to collagen with an affinity comparable to that of mature vWF, inhibits collagen-induced platelet aggregation, is cross-linked with laminin, and also serves as a ligand for very-late antigen 4 integrin. These observations from in vitro experiments suggest that pp-vWF is incorporated in the extracellular matrix and affects the cell-matrix interaction and that pp-vWF functions in leukocyte recruitment to inflammatory and vascular injury sites. We, therefore, hypothesize that pp-vWF might be involved in the induction and/or progression of mesangial proliferative glomerulonephritis. To test this hypothesis, we examined the kinetics of the immunostaining of the molecule detectable by an affinity-purified anti-pp-vWF antibody in rat glomeruli in monoclonal antibody 1-22-3 induced glomerulonephritis. Immunostaining by pp-vWF antibody was observed in the nuclear rim of mesangial cells in monoclonal antibody 1-22-3 induced glomerulonephritis. Positive staining first appeared on day 10 after monoclonal antibody injection, when mesangial cell proliferation and mesangial matrix expansion had already begun. Staining was still detected on day 56, when morphologic alterations observed by light microscopy had been normalized. The pp-vWF antibody recognized molecule appeared later than alpha-smooth muscle actin or collagen type I. Positive staining was not detected in cultured mesangial cells. It should be noted that the positive staining by pp-vWF antibody in mesangial cells was still detected in previously injured glomeruli that have almost recovered normal morphology. These observations indicate that positive staining by pp-vWF antibody could be a very useful marker for identifying a past episode of injury in mesangial cells.

Animals↗
PubMed1999

[Successful treatment of acute renal failure in a patient with essential mixed cryoglobulinemia using prednisolone and cryofiltration].

We report a case of acute renal failure associated with cryoglobulinemic glomerulonephritis. The patient, a 49-year-old woman, was referred to our hospital because of acute nephritic syndrome. After admission, she developed oliguria, and hemodialysis was instituted. Renal biopsy was performed and the specimens showed moderate endocapillary proliferation, large deposits filling the capillary lumen ("intraluminal thrombi"), and a double-contoured appearance, which are typical morphologic features of cryoglobulinemic glomerulonephritis. Immunoelectrophoresis showed a monoclonal increase of IgM kappa. On the basis of these findings, we diagnosed type II essential mixed cryoglobulinemia. Cryofiltration was performed with oral administration of prednisolone. Following the start of therapy, the patient's renal function gradually improved. Because of severe hypoproteinemia, cryofiltration was discontinued after three sessions. However, renal function recovered and was maintained with prednisolone only. This case shows that acute oliguric renal failure caused by cryoglobulinemic glomerulonephritis can be reversible if immunosuppressive therapy, together with plasmapheresis in more severe cases, is instituted promptly.

Acute Kidney Injury↗
PubMed1999

Oral clonidine to control hypertension after head injury.

Clonidine, an alpha2 agonist, was administered through a nasogastric tube for the treatment of hypertension in a head-injury patient with elevated plasma catecholamines. Haemodynamic parameters were stabilized with a reduction in sympathetic nervous activity. The plasma clonidine concentration, measured by radioimmunoassay, rapidly increased following the administration. After cessation of oral administration of clonidine, mean arterial blood pressure gradually increased. So clonidine was again administered orally and good blood pressure control was achieved and no change in consciousness level was observed. Oral clonidine was useful and effective for hypertension in this head injury patient.

Administration, Oral↗
PubMed1998

Rat maf-related factors: the specificities of DNA binding and heterodimer formation.

maf is a family of genes encoding bZIP transcription factors. We isolated two cellular maf-related cDNAs, maf-1 (mafB) and maf-2 (c-maf), from rat and determined the specificities of DNA binding and heterodimer formation. Although both Mafs strongly bind to MARE, the consensus Maf recognition sequence (MARE, -TGCTGACTCAGCA-), originally identified by v-Maf protein Maf-1, recognizes a number of sequences containing only the first half of the MARE, -GCTGAC-. On the other hand, no such consensus short sequence could be determined for Maf-2. We determined the specificities of heterodimer formation with all members of the Jun and Fos family. In contrast to v-Maf which forms heterodimers with all Jun and Fos proteins, Maf-1 heterodimerizes with all four Fos proteins, but not at all with the three Jun proteins. Maf-2 heterodimerizes with c-Fos. We have also found that heterodimer formation of Maf-2 with c-Fos dramatically changes the specificity of DNA binding and trans-activation activity from that of the Maf-2 homodimer. These results show that Maf-1 and Maf-2 have significantly different properties and they might have different target genes and functions, in spite of the similarity of their bZip domain structure.

Animals↗
PubMed1998

The pharmacokinetic change of lidocaine by catecholamines using isolated perfused rat liver (IPRL).

We hypothesized that changes in the pharmacokinetics of lidocaine might reveal changes in portal circulation induced by catecholamines. Isolated perfused rat liver (IPRL) was selected as an experimental model, since experimental conditions in this model could be regulated. The liver was perfused with a recirculating system at a constant flow rate of 20 ml/min. Two milligrams of lidocaine was administered along with one of three drugs, dopamine, norepinephrine or adenosine triphosphate. The fractional transfer rate constants, k21 and k12, from medium to liver and liver to medium, respectively, and ke, the elimination rate constant, were calculated using a two-compartment model with the SAAM II program. Curves of decay of lidocaine from the recirculating medium consisted of a fast and a slow component. Norepinephrine and high-dose dopamine significantly increased k12, while low-dose dopamine significantly increased k21 and ke compared with control values. Thus, norepinephrine and high-dose dopamine increased lidocaine transfer rate from liver to medium, while low-dose dopamine increased the transfer rate from medium to liver and the rate of elimination from liver. These findings suggest that norepinephrine and high-dose dopamine inhibit hepatic drug uptake and that low-dose dopamine improves uptake in IPRL.

Anesthetics, Local↗
PubMed1998

The significance of the Trp 64 Arg mutation of the beta3-adrenergic receptor gene in impaired glucose tolerance, non-insulin-dependent diabetes mellitus, and insulin resistance in Japanese subjects.

It has been reported that the Trp 64 Arg mutation of the human beta3-adrenergic receptor (beta3-AR) gene is related to an earlier age of onset of non-insulin-dependent diabetes mellitus (NIDDM) and features of insulin resistance and weight gain in morbidly obese patients. However, such findings have not been consistent in varying ethnic populations. In the present study, we investigated the frequency of the Trp 64 Arg mutation of the human beta3-AR gene in Japanese control subjects (n = 253) and in NIDDM (n = 314) and impaired glucose tolerance (IGT) patients (n = 100). We compared the frequency of the mutation with the body-mass index (BMI) in these groups and with the metabolic clearance rate (MCR) of glucose in the NIDDM patients. A Trp 64 Arg mutation was observed in 36.7%, 31.6%, and 37.0% of the control, NIDDM, and IGT subjects, respectively. The frequency of the homozygotes for the mutation was 4.3%, 4.8%, and 3.0%, respectively. Neither the genotype frequency (Trp/Arg, Arg/Arg) nor the frequency of the mutated allele was significantly different among the three groups. The BMI of the subjects with the mutation was not significantly higher than that of the subjects without the mutation in each group. Furthermore, the allele frequency (A) was not different among the subjects with different BMIs (BMI < 22.0, 22.0 < or = BMI < or = 26.4, BMI > 26.4) in each group. In a separate group of NIDDM patients, the MCR of the subjects with intermediate BMIs (22.0 < or = BMI < or = 26.4) with the mutation tended to be lower than that of those without the mutation. In addition, the MCR of the subjects with the mutation in this group was significantly lower compared with that of those with a BMI less than 22. These results indicate that the Trp 64 Arg mutation of the beta3-AR gene may not contribute to the development of NIDDM or be a determinant of obesity in the Japanese population. However, the mutation may contribute to insulin resistance in NIDDM patients with an intermediate BMI.

Adult↗
PubMed1998

Oral clonidine for sedation and analgesia in a burn patient.

Clonidine has both analgesic and sedative actions, and it has been used in a variety of settings as a sedative, or both. We administered oral clonidine with intravenous ketamine to a burn patient to control severe pain. Clonidine produced good analgesia and sedation. In addition, clonidine counterbalanced the sympathetic stimulation of ketamine by virtue of its action in reducing sympathetic outflow. The combination of these two drugs may be useful for burn patients with hypertension or myocardial ischemia.

Administration, Oral↗
PubMed1998

Clinical aspects of indocyanine green pharmacokinetics following portal vein administration.

AIMS: This study was performed to demonstrate that measurement of the clearance of indocyanine green (ICG) following portal vein administration (CLpv) is more useful than that following peripheral vein administration (CLiv) for evaluating intrinsic clearance and hepatic blood flow. METHODS: Eight patients, aged 55.9 +/- 8.8 years, who underwent partial hepatectomy were studied. ICG was administrated to all patients via peripheral and portal veins before and after enflurane anaesthesia and soon after surgery. ICG concentrations were measured by h.p.l.c. Non-compartmental analysis was applied to the ICG time-concentration data obtained. The area under the curve (AUC), clearance (CL), mean residence time (MRT) and volume of distribution (V) were calculated using this method of analysis. RESULTS: CLpv was significantly decreased from 26.4 +/- 13.2 ml kg(-1) min(-1) before anaesthesia, to 19.5 +/- 7.0 (P < 0.05) and 12.7 +/- 5.3 (P < 0.01) ml kg(-1) min(-1), respectively, during anaesthesia and after partial hepatectomy; These values were 72.1% (P < 0.01) and 48.5% (P < 0.01) of that observed at percutaneous transhepatic portography (PTP). CLiv was significantly decreased from 14.6 +/- 5.3 ml kg(-1) min(-1) before anaesthesia, to 9.4 +/- 3.6 (P < 0.05) and 9.8 +/- 4.1 (P < 0.05) ml kg(-1) min(-1), respectively, after partial hepatectomy and 12 h after operation; These values were 68.9% (P < 0.05) and 73.5% (P < 0.05) of the value at PTP. The other pharmacokinetic parameters examined, V and MRT, did not change significantly during anaesthesia or after surgery. CONCLUSION: The clearance of ICG after portal administration was useful for estimating hepatic blood flow and intrinsic clearance in perioperative management of liver surgery.

Aged↗
PubMed1998

Tumor necrosis factor-alpha regulates the gene expression of macrophage migration inhibitory factor through tyrosine kinase-dependent pathway in 3T3-L1 adipocytes.

Macrophage migration inhibitory factor (MIF) has been rediscovered as a proinflammatory cytokine, pituitary hormone, and glucocorticoid-induced immunoregulator. We have recently identified the expression of MIF in adipocytes and found that tumor necrosis factor (TNF)-alpha stimulates its secretion from 3T3-L1 adipocytes. Since adipocytes are regarded as a potential source of various biologically active substances, we examined in more detail the effect of TNF-alpha on MIF expression in 3T3-L1 adipocytes in the present study. We found that TNF-alpha induced MIF mRNA in dose- and time-dependent manners. After stimulation with TNF-alpha, the amount of intracellular MIF protein was unchanged or slightly decreased, concomitant with increased release of this protein into the extracellular space. This observation indicates that TNF-alpha stimulates MIF secretion from the constitutively expressed intracellular pool of 3T3-L1 adipocytes and promotes de novo synthesis of MIF. From evaluation of the mechanism of MIF gene expression, we found that tyrosine kinase inhibitors, either genistein or herbimycin A, suppressed the MIF mRNA induction by TNF-alpha. The results suggest the possibility that upregulation of MIF mRNA expression by TNF-alpha is mediated by a tyrosine kinase-dependent pathway. Taken together, the present observations shed light on the role of MIF in the metabolism of obesity and diabetes.

3T3 Cells↗