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Biomedical subjects

T Naito

Publications and source records attributed to T Naito.

At least 91 records · Page 5Linked to original sources
PubMed1999

Evaluation of the PD adequest program in Japanese patients on peritoneal dialysis.

To perform adequate peritoneal dialysis, it is necessary to individualize the dialysis regimen. PD Adequest is a software program based on the three-pore model that can be used to predict solute clearance and ultrafiltration volume during peritoneal dialysis. We evaluated the ability of this program to predict the solute clearance and ultrafiltration volume in Japanese patients on peritoneal dialysis. The weekly creatinine clearance and weekly urea Kt/V were determined in 45 patients. The PD Adequest was used to simulate their current dialysis regimens and the predicted values of these parameters were calculated. Strong positive correlations were obtained between the actual and predicted weekly creatinine clearance (r = 0.993) and weekly urea Kt/V (r = 0.991). In conclusion, this program is potentially useful for designing peritoneal dialysis regimens in Japanese patients, even though they have a smaller body mass than Canadians and Americans for whom it was designed.

Adolescent↗
PubMed1999

A case of antiphospholipid antibody syndrome diagnosed after thrombosis of an arteriovenous shunt.

A 32-year-old male dialysis patient with lupus nephritis was admitted because of shunt obstruction. The arteriovenous fistula was reconstructed, but obstruction recurred twice within several hours after surgery. A high blood level of anticardiolipin beta2-glycoprotein I antibody suggested that shunt obstruction was caused by a thrombotic tendency related to the antiphospholipid antibody syndrome. Accordingly, for the third shunt procedure, antiplatelet therapy (which had been commenced for systemic lupus erythematosus) was combined with dalteparin sodium from before surgery and warfarin was added postoperatively. This regimen prevented shunt obstruction. In conclusion, hemodialysis patients who suffer repeated shunt obstruction should be examined for antiphospholipid antibody syndrome.

Adult↗
PubMed1999

Clinicopathological study of myeloperoxidase anti-neutrophil cytoplasmic antibody-associated glomerulonephritis.

AIMS: To investigate the potential prognostic factors for myeloperoxidase anti-neutrophil cytoplasmic antibody- (MPO-ANCA) associated glomerulonephritis. MATERIALS: The clinical and pathological findings were reviewed in 17 patients with this type of glomerulonephritis. METHODS: The relationship between the outcome and various clinical and pathological factors were assessed. The relationship between the blood MPO-ANCA level and cellular crescent formation was also investigated. RESULTS: Patients who died had a significantly lower serum albumin and creatinine clearance than those who survived, but there were no differences of age, blood MPO-ANCA, urinary protein, and serum creatinine levels or cellular crescent formation between the two groups. There was a close relationship between blood MPO-ANCA levels and cellular crescent formation. CONCLUSIONS: Hypoalbuminemia and renal dysfunction may be indicators of a poor prognosis in MPO-ANCA-associated glomerulonephritis. Patients with high blood levels of this antibody and increased cellular crescent formation appear to have active disease, but these factors are not statistically associated with a fatal outcome. Therefore, aggressive treatment may be indicated in patients with active disease initially.

Adult↗
PubMed1999

[Clinical experiences and problems with home medical treatment in an orthopedic clinic].

Twenty-five patients who received home medical treatment were reviewed. There were 11 males and 14 females, with a mean age of 77 years. In an orthopedic clinic, it is difficult to secure the time for to visit a patient's home. Another problem for doctor is that the medical fee for home treatment is very low. To promote home treatment by orthopedists, it is important to secure the time to visit a patient's home, to improve the fees for home treatment, and to establish a connection with a visiting nurse care station and visiting rehabilitation workers.

Aged↗
PubMed1998

Putative pheromone receptors related to the Ca2+-sensing receptor in Fugu.

By a combination of PCR with degenerate primers and low stringency probing, we have isolated a large family of genes related to the Ca2+-sensing receptor from the genome of Fugu rubripes. One of the genes (type I) is the Fugu homologue of the Ca2+-sensing receptor. The remaining genes can be divided into five classes (type II-VI) on the bases of gene structure. In several types, the genes occur in clusters as tandem arrays. These genes appear to be the homologues of the vomeronasal pheromone receptors recently described in rodents. The Fugu genes are expressed in the tissues of the nose, suggesting that they may have a similar physiological role.

Animals↗
PubMed1998

Polymorphisms of thymidine kinase gene in herpes simplex virus type 1: analysis of clinical isolates from herpetic keratitis patients and laboratory strains.

Drug-resistance of herpes simplex virus (HSV) is caused most frequently by mutation of the viral thymidine kinase (TK) gene. To elucidate the significance of detecting nucleotide changes of the TK gene for screening drug-resistant viruses, the frequency and variation of the genetic polymorphisms in the whole coding region of the TK gene were studied in 14 acyclovir-susceptible HSV type 1 (HSV-1) clinical isolates from 14 patients with epithelial herpetic keratitis. Two reference HSV-1 laboratory strains, McKrae and PH, and two acyclovir-resistant variants of the PH strain were also studied as controls. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing detected nucleotide differences at 24 positions, and amino acid substitutions at 12 codons in the TK gene of the examined viruses. Nucleotide diversity of 0.0029 per base (the average number of nucleotide substitutions of 3.3 per 1,131 base pairs) in the TK gene in the clinical isolates was comparable to 0.0037 per base of the whole HSV-1 genome in Japanese isolates reported previously. PCR-SSCP analysis of the acyclovir-resistant strains easily detected aberrantly shifted bands by comparing them with those of the parental strain, followed by the quick determination of mutated sequences. These results suggest that detection of nucleotide changes of the TK gene is useful for serial observation of persistent or recurrent HSV infection as observed in immunocompromised hosts, but that it is not useful for screening drug-resistant viruses from nonepidemic clinical isolates because of the comparable genetic polymorphisms in the TK gene as in the whole HSV-1 genome.

Acyclovir↗
PubMed1998

Role of curdlan sulfate in the production of beta-chemokines and interleukin-16.

The blocking effect of curdlan sulfate (CRDS) on human immunodeficiency virus (HIV) infection has been thought to be related to inhibition of the binding of HIV-1 envelope glycoprotein (gp120) and CD4 molecules. However, recent reports have indicated that blocking the binding of gp120 to CD4 by CRDS only makes a small contribution to the inhibition of HIV-1 infection. We report here that the effect of CRDS on the production of beta-chemokines and cytokines might be important in the inhibition of HIV-1 infection, in addition to interference with the binding of gp120 to CD4+ cells.

Antiviral Agents↗
PubMed1998

Aggressive non-Hodgkin's lymphoma after successful eradication of Helicobacter pylori and regression of gastric lymphoma of mucosa-associated lymphoid tissue.

A 57-year-old woman presented to our clinic with low-grade gastric lymphoma of mucosa-associated lymphoid tissue (stage IE) and Helicobacter pylori infection. She received a 2-week course of omeprazole and clarithromycin, resulting in eradication of H. pylori and histological disappearance of the lymphoma. However, 9 months later (May 1996), multiple mass lesions were found around the pancreas and hepato-duodenal ligament on abdominal computed tomography. Inguinal lymph node biopsy revealed aggressive nodal type B-cell non-Hodgkin's lymphoma, diffuse large cell type. She received chemotherapy with cyclophosphamide, adriamycin, vincristine, and prednisolone, but failed to achieve remission and died in December 1996. There was no evidence of recurrent gastric lymphoma. This case emphasizes the importance of performing follow-up examinations to detect other neoplasms in patients with gastric lymphoma of mucosa-associated lymphoid tissue.

Diagnosis, Differential↗
PubMed1998

Chemiluminescent determination of cholesterol hydroperoxides in human erythrocyte membrane.

A method for separating, detecting, and quantifying cholesterol hydroperoxide (Ch-OOH) based on extraction, purification by solid-phase extraction cartridge, high-performance liquid chromatography with chemiluminescent detection (HPLC-CL), and liquid chromatography-mass spectrometry has been developed for human erythrocyte membrane. We prepared standard compounds of the cholesterol 5alpha-, 7alpha-, and 7beta-hydroperoxides (Ch 5alpha-OOH, Ch 7alpha-OOH, and Ch 7beta-OOH). An octyl silica column with methanol/water/acetonitrile 89:9:2 (by vol) as eluent was used to determine Ch-OOH. HPLC-CL that incorporated cytochrome c and luminol as the post-column luminescent reagent was used. We also investigated the optimal assay conditions and how to prevent formation of artifact Ch-OOH. Analysis of erythrocyte membranes from seven healthy volunteers identified Ch 7alpha-OOH and Ch 7beta-OOH, but not Ch 5alpha-OOH, as commonly occurring components. The respective mean concentrations of Ch 7alpha-OOH and Ch 7beta-OOH were 2.5+/-1.6 and 5.4+/-3.5 pmol/mL blood.

Antioxidants↗
PubMed1998

Curved chest tube for drainage of malignant pleural effusion.

Thoracentesis with a chest tube insertion and drainage of large pleural effusion is widely performed in patients with malignant lung diseases. One potential problem with a conventional chest tube placement is occasional incomplete evacuation of effusion owing to inappropriate position of the tip where the drainage holes opened. We have developed a curved chest tube and evaluated the position of tip placement just after the placement and before removal on plain chest X-ray in 20 patients with massive pleural effusions due to lung cancer. In 15 of the 20 patients, the tip of the tube was successfully positioned at the paravertebral gutter in posterobasal with higher drainage efficacy compared with other patients whose tube tips happened to be positioned at other sites. There were no significant complications. This study suggested that the curved chest tube would be safe and useful in completing drainage of pleural effusion.

Adult↗
PubMed1998

Circular chromosome formation in a fission yeast mutant defective in two ATM homologues.

Telomeres, found at chromosomal ends, are essential for stable maintenance of linear chromosomes in eukaryotes. The ATM family of genes, including budding yeast TEL1 (refs 1,2), fission yeast rad3+ (ref. 3) and human ATM (ref. 4), have been reported to be involved in telomere length regulation, although the significance of the telomere phenotypes observed with the mutated genes remains elusive. We have cloned tel1+, another fission yeast ATM homologue, and found that a tel1rad3 double mutant lost all telomeric DNA sequences. Thus, the ATM homologues are essential in telomere maintenance. The mutant grew poorly and formed irregular-shaped colonies, probably due to chromosome instability, however, during prolonged culture of the double mutant, cells forming normal round-shaped colonies arose at a relatively high frequency. All three chromosomes in these derivative cells were circular and lacked telomeric sequences. To our knowledge, this is the first report of eukaryotic cells whose chromosomes are all circular. Upon meiosis, these derivative cells produced few viable spores. Therefore, the exclusively circular genome lacking telomeric sequences is proficient for mitotic growth, but does not permit meiosis.

Ataxia Telangiectasia Mutated Proteins↗
PubMed1998

Removal of endotoxin and cytokines by plasma exchange in patients with acute hepatic failure.

OBJECTIVES: To compare the circulating concentrations of endotoxin and cytokines in patients with fulminant hepatitis and patients with the severe form of acute hepatitis, and to assess the effects of plasma exchange on the circulating concentrations of these inflammatory mediators in patients with acute hepatic failure. DESIGN: Prospective, consecutive entry study of patients meeting fulminant hepatitis criteria and the severe form of acute hepatitis criteria. SETTING: University hospital, intensive care unit. PATIENTS: Five patients with fulminant hepatitis, eight patients with the severe form of acute hepatitis, two patients with acute-on-chronic hepatic failure, and one patient with postoperative hepatic failure. INTERVENTIONS: Plasma endotoxin, serum tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 were determined on admission in five patients with fulminant hepatitis and eight patients with the severe form of acute hepatitis. Circulating concentrations of the inflammatory mediators were measured before and after a single course of plasma exchange in eight patients with acute liver failure, including five patients with fulminant hepatitis, two patients with acute-on-chronic hepatic failure, and one patient with postoperative hepatic failure. MEASUREMENTS AND MAIN RESULTS: TNF-alpha and IL-6 in patients with fulminant hepatitis were significantly higher than in patients with the severe form of acute hepatitis, whereas endotoxin concentrations did not differ between patients with fulminant hepatitis or the severe form of acute hepatitis. IL-1beta was not detectable in patients with either fulminant hepatitis or the severe form of acute hepatitis. Plasma endotoxin concentrations decreased immediately after plasma exchange. Serum concentrations of TNF-alpha and IL-6 were significantly lower after plasma exchange than before plasma exchange. CONCLUSION: TNF-alpha and IL-6 may be important in the pathogenesis of the clinical symptoms that differentiate fulminant hepatitis from the severe form of acute hepatitis, and plasma exchange removes these inflammatory mediators from the circulation of patients with severe liver disease.

Adolescent↗
PubMed1998

Abnormality of very long-chain fatty acids of erythrocyte membrane in alcoholic patients.

Profiles of very long-chain fatty acids were studied in the erythrocyte membrane of five alcoholic patients. We identified three fatty acids as cis-16-pentacosenoic acid (C25:1), cis-17-hexacosenoic acid (C26:1), and hexacosenoic acid (C26:1), and hexacosanoic acid (C26:0) by gas chromatography-mass spectrometry. The ratios of C26:1/C22:0, C26:0/C22:0, C24:1/C22:0, and C24:0/C22:0 were increased. These findings suggest that active oxygen species or free radicals generated by chronic alcohol consumption in alcohol patients interrupt the peroxisomal beta-oxidation of fatty acids, because very long-chain fatty acids are mainly metabolized by the peroxisomal beta-oxidation system. This is the first study showing accumulation of very long-chain fatty acids in the erythrocyte membrane of alcoholic patients.

Alcoholism↗