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Biomedical subjects

K Tada

Publications and source records attributed to K Tada.

At least 145 records · Page 8Linked to original sources
PubMed1996

Comparison among performances of a ligase chain reaction-based assay and two enzyme immunoassays in detecting Chlamydia trachomatis in urine specimens from men with nongonococcal urethritis.

We evaluated the performances of a ligase chain reaction (LCR)-based assay and two enzyme immunoassays (Chlamydiazyme and IDEIA) in the detection of Chlamydia trachomatis in urine specimens. We compared the results of testing urine specimens by these assays with those of urethral swab culture by examining samples from 131 men with nongonococcal urethritis. Discrepant results were analyzed by testing urethral swab specimens for C. trachomatis by a PCR-based assay. After the resolution of discrepant results, the sensitivity of urethral swab culture was 85.3%, whereas those of the LCR assay, Chlamydiazyme, and IDEIA with urine specimens were 94.1, 82.4, and 94.1%, respectively. The LCR assay and IDEIA were more sensitive than was urethral swab culture. In addition, the LCR assay, with a sensitivity equal to that of IDEIA, was more specific. Overall, the LCR assay proved to be superior to the enzyme immunoassays in detecting C. trachomatis in urine specimens. Testing urine specimens by LCR assay should be a helpful alternative method for diagnosing C. trachomatis urethral infection in men with nongonococcal urethritis.

Chlamydia Infections↗
PubMed1996

A cytotoxic nonstructural protein, NS1, of human parvovirus B19 induces activation of interleukin-6 gene expression.

We examined the biological function of a nonstructural regulatory protein, NS1, of human parvovirus B19. Because of the cytotoxic activity of NS1, human hematopoietic cell lines, K562, Raji, and THP-1, were established as transfectants which produce the viral NS1 protein upon induction by using bacterial lactose repressor/operator system. NS1 was significantly produced in the three transfectant cells in an inducer dose- and time-dependent manner. Surprisingly, these three transfectants secreted an inflammatory cytokine, interleukin-6 (IL-6), in response to induction. However, no production of other related cytokines, IL-1beta, IL-8, or tumor necrosis factor alpha, was seen. Moreover, NS1-primed IL-6 induction was transiently demonstrated in primary human endothelial cells. Analysis with luciferase reporter plasmids carrying IL-6 promoter mutant fragments demonstrated that NS1 effect is mediated by a NF-kappaB binding site in the IL-6 promoter region, strongly implying that NS1 functions as a trans-acting transcriptional activator on the IL-6 promoter. Our novel finding, IL-6 induction by NS1, supports the possible relationship between parvovirus B19 infection and polyclonal activation of B cells in rheumatoid arthritis and indicates that NS1 protein may play a significant role in the pathogenesis of some B19-associated diseases by modulating the expression of host cellular genes.

Animals↗
PubMed1996

[Unilateral multicystic dysplastic kidney in an adult: report of a case].

A case of unilateral multicystic dysplastic kidney in a 52-year-old woman is reported. Two abnormal round-like calcifications in left upper quadrant abdomen were found on upper gastrointestinal roentgengraphy for health screening. The computerized tomographic (CT) scan revealed a very small left kidney which was not enhanced and the ring and diffuse calcifications in it. It was not visualized by drip infusion pyelography. Left nephrectomy was performed. The kidney, which was very small, had two cysts the walls of which were calcified. The left ureter and renal vessels were absent. Histological appearance shows typical multicystic dysplastic kidney (MCDK). Literature is reviewed. However, the therapy for MCDK is still controversial.

Calcinosis↗
PubMed1996

[Anesthesia for cesarean section: drug transfer to fetus during anesthesia].

One case of prenatally diagnosed congenital diaphragmatic hernia was reviewed in terms of the anesthetic managements. Concentrations of diazepam, pancuronium and fentanyl were measured in maternal, fetal and umbilical serum. As expectedly, the transition of diazepam through the placenta was large and the concentration of diazepam in the fetal serum was equal to that of maternal serum, but only a small amount of pancuronium was transferred.

Adult↗
PubMed1995

Leukoencephalopathy in childhood hematopoietic neoplasm caused by moderate-dose methotrexate and prophylactic cranial radiotherapy--an MR analysis.

PURPOSE: The main purpose of this study was to determine influential factors related to minor leukoencephalopathy (LEP) caused by moderate-dose methotrexate (MTX) and prophylactic cranial radiotherapy (CRT) in childhood hematopoietic malignancies. We also compared the incidence of LEP following this treatment to that reported in the literature following treatment with high-dose MTX alone. METHODS AND MATERIALS: Thirty-eight pediatric patients of hematopoietic malignancies (37 acute lymphoblastic leukemias, 1 non-Hodgkin lymphoma) who were given CRT (18-24 Gy) as well as prophylactic intrathecal and per os MTX were studied for leukoencephalopathy by magnetic resonance (MR) imaging. All the patients were free from grave neuropsychiatric disturbances. The data were examined to elucidate the influential ones of five factors (patients' age, doses of intrathecal and per os MTX, dose of CRT, interval between treatment, and MR study) to develop LEP using multiple regression analysis. To compare the effect of moderate-dose MTX and prophylactic CRT on LEP to that of high-dose MTX alone, we conducted literature review. RESULTS: Seven out of 38 patients (18%) developed LEP. From multiple regression analysis and partial correlation coefficients, the age and CRT dose seemed influential in the subsequent development of LEP. The incidence of LEP following treatment with moderate-dose MTX and prophylactic CRT appears to be less than that reported in the literature following treatment with intravenous high-dose MTX. However, even moderate-dose MTX in combination with CRT can result in a significant incidence of MR-detectable LEP, particularly in children 6 years of age or younger receiving 24 Gy. CONCLUSION: Leukoencephalopathy was caused by moderate-dose MTX and prophylactic CRT in pediatric patients, probably less frequently than by high-dose MTX treatment alone. The influential factors were patient's age and CRT dose.

Adolescent↗
PubMed1995

A novel splicing mutation in propionic acidemia associated with a tetranucleotide direct repeat in the PCCB gene.

Propionic acidemia is an inborn error of organic acid metabolism caused by a deficiency of propionyl Coenzyme A (CoA) carboxylase. cDNAs sequenced from a beta subunit deficient Japanese patient (no. 187) showed an in-frame 57-bp deletion in one allele. Genomic DNA analysis revealed a four-nucleotide deletion of bases 3 to 6 in the 3' intron adjacent to the deleted exon, which disrupted the consensus 5' splice signal and caused exon skipping. This deletion removed one-half of a tetranucleotide direct repeat at the splice junction and presumably resulted from slipped mispairing.

Acyl Coenzyme A↗
PubMed1995

Diet differentially regulates glucokinase and L-type pyruvate kinase gene expression in rat liver.

The regulation of gene expression of glucokinase (GK) and L-type pyruvate kinase (L-PK) in rat liver was investigated and compared with the previously reported regulation of lipogenic enzymes. Experiments were conducted in which the time courses and responses to diet quantity of mRNA concentrations and enzyme activities after refeeding a carbohydrate/protein diet (CP) to food-deprived rats were measured. The effects of dietary nutrients on the gene expression were investigated in rats refed either the CP diet, a carbohydrate diet without protein (C), a protein diet without carbohydrate (P), or a carbohydrate/protein/corn oil diet (CPF). The effects of the CPF diet on the gene expression after insulin treatment to diabetic rats were also investigated. After refeeding the CP diet, GK mRNA concentration and enzyme activity reached maximum levels in 2 h and 16-24 h, respectively, whereas those of L-PK peaked in 16 h and 48 h, respectively, similar timecourse to lipogenic enzymes. Moreover, GK mRNA concentrations were maximal in rats fed 20% of the ad libitum diet intake, and L-PK mRNA concentrations, like lipogenic enzyme mRNA, were maximal in rats fed approximately 50% of ad libitum intake. GK mRNA concentrations were significantly increased in parallel with an increase in plasma insulin and glucose concentrations. GK and L-PK mRNA and enzyme levels in rats fed the C diet were comparably induced to the levels in those fed the CP diet. L-PK mRNA induction by the CP diet was significantly reduced by dietary polyunsaturated fatty acids (CPF diet), whereas the GK mRNA induction was not significantly reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Role of Lys108 in the enzymatic activity of RNase Rh from Rhizopus niveus.

In order to elucidate on the mechanism of action of RNase Rh from Rhizopus niveus, we investigated the role of Lys108, which is conserved among the RNase T2 family RNases except for two cases. The RNase activities of Lys108 mutant RNases, RNase RNAP K108R and K108L, are about 33.5 and 3.1% of that of the wild type enzyme, respectively. The relative rates of cleavage of dinucleoside phosphates by these two mutant enzymes were comparable to those with RNA as a substrate. The kinetic parameters of RNases RNAP K108R and K108L towards XpGs (where X is one of A, G, U, and C) were measured. The data indicated that the Km values of the two mutant enzymes are similar to those of the wild-type enzyme. The rates of release of the four nucleotides from RNA by digestion with the mutant enzymes were in the order A > G > U > C, which is qualitatively the same as that of the wild-type enzyme. From these data, we concluded that the Lys108 residue participates in the catalytic process, but not in the binding, and the positive charge of Lys108 is indispensable for the catalytic process, that is, the positive charge of Lys108 may stabilize the pentacoordinated intermediate in the transition state as proposed in the case of Lys41 in RNase A, or may polarize the phosphate moiety of the substrate.

Amino Acid Sequence↗
PubMed1995

DNA gyrase mutations in quinolone-resistant clinical isolates of Neisseria gonorrhoeae.

Eight quinolone-resistant clinical isolates of Neisseria gonorrhoeae were shown to carry mutations in their GyrA proteins. Six isolates had a single amino acid change of serine to phenylalanine at the position corresponding to Ser-83 in Escherichia coli. In addition to the change of serine to phenylalanine, two isolates had another change of aspartic acid to asparagine at the position corresponding to Asp-87 in E. coli.

Amino Acid Sequence↗
PubMed1995

Endogenous ET-1 contributes to liver injury induced by galactosamine and endotoxin in isolated perfused rat liver.

Injury to hepatocytes most likely occurs via disturbances in the microcirculation. The role of vasoconstriction due to the effect of endogenous endothelin-1 (ET-1) in the development of galactosamine (GalN)- and lipopolysaccharide (LPS)-induced liver injury was investigated. Using the multiple indicator dilution technique, we measured the volume of the hepatic sinusoids and the apparent Disse space as indicators of overall hepatic microcirculation. Serum purine nucleoside phosphorylase activity as a marker of damage to nonparenchymal cells increased and the volume of the sinusoids and the Disse space decreased prior to hepatocyte damage in rats treated intraperitoneally with GalN and LPS. Moreover, the amount of ET-1 release was elevated. When livers from untreated rats were perfused with ET-1 in a recirculating system, hepatocyte damage was observed similar to experiments with GalN and LPS. A monoclonal anti-endothelin antibody, AwETN40, diminished the extent of liver injury caused by GalN and LPS in isolated perfused rat liver. The present study suggests that vasoconstriction is an early event in GalN- and LPS-induced liver injury and that the development of hepatocyte damage is mediated via microcirculatory disturbances due to endogenous ET-1.

Alanine Transaminase↗
PubMed1995

Amiloride-sensitive Na+/H+ antiporter in basolateral membrane of hamster ascending thin limb of Henle's loop.

The mechanisms of intracellular pH (pHi) regulation were investigated in the in vitro microperfused hamster ascending thin limb (ATL) of Henle's loop with the fluorescent pH indicator, 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. pHi of ATL cells was 7.05 +/- 0.02 (n = 30) when microperfused with a CO2/HCO(3-)-buffered solution. In HEPES-buffered solution, pHi was 7.10 +/- 0.02 (n = 16), which was significantly higher than the value in CO2/HCO(3-)-buffered solution (P < 0.05, n = 16). In HEPES-buffered solution, elimination of Na+ and addition of 1 mM amiloride to basolateral solution decreased the pHi by 0.12 +/- 0.03 (n = 6) and 0.11 +/- 0.02 (n = 5) at 1 min, respectively. The same manipulations in the luminal solution had no effect on pHi. One millimolar of N-ethylmaleimide (NEM) added to either side of ATL caused no significant change in pHi. Elimination of K+ on either side of ATL did not alter pHi. After adding 20 mM NH4Cl to basolateral solution, pHi instantaneously increased from 7.17 +/- 0.01 to 7.51 +/- 0.03 (n = 3), and then returned to steady-state level of 7.21 +/- 0.05 (n = 15) in 3 min. Removal of NH4Cl from basolateral solution then caused a rapid fall in pHi to 6.31 +/- 0.05 (n = 15), followed by spontaneous recovery at a rate of 0.43 +/- 0.06 unit/min (n = 15).(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1995

[ACTH-independent bilateral adrenocortical macronodular hyperplasia (AIMAH): report of a case].

We treated a case of ACTH-independent bilateral adrenocortical macronodular hyperplasia (AIMAH), a rare disease. The patient was a 49 year-old man having chief complaints of facial edema, muscle wasting and typical Cushing's syndrome symptoms. He was diagnosed with AIMAH by specific hormonal tests for Cushing's syndrome and CT scan. Bilateral total adrenalectomy was performed in a two-stage operation for bilateral macronodular adrenocortical hyperplasia. The resected adrenal tumor weighed 57 g on the right side and 78 g on the left, and both had a yellowish nodular surface. The histological appearance was typical AIMAH. A total of 23 AIMAH reported cases was reviewed.

Adrenal Cortex↗
PubMed1995

[Parathyroid selective venous sampling].

It is important to localize the site of abnormal parathyroid glands in treatment of primary hyperparathyroidism. Selective venous sampling with parathyroid hormone assay is one of the methods for localization of adenoma or hyperplasia in primary hyperparathyroidism. Since Reitz first described it in 1969, it has been improved during the last two decades and there is a high sensitivity (70-80%). Especially in those cases, localization is unknown in imaging methods, the first operation fails or the patients has previously been explored in the neck, venous sampling becomes a very useful method. How to perform, indication, performance, strengths and weakness of selective venous sampling is described here.

Blood Specimen Collection↗
PubMed1995

Clinical significance of antiphospholipid antibodies in fulminant hepatic failure.

We examined the incidence of antiphospholipid antibodies (APA) in patients with fulminant hepatic failure (FHF) and various liver diseases using the enzyme-linked immunosorbent assay (ELISA), and assessed possible correlations with the pathophysiology of these diseases. The APA assay employed cardiolipin (CL), phosphatidylserine (PS), and phosphatidylinositol (PI) as antigens. Anti-CL IgA antibody was detected in 13/14 (92.9%) patients with FHF. The incidence of anti-CL-IgG, anti-CL-IgM, anti-PS-IgG, and anti-PI-IgG was 14.3%, 35.7%, 64.3%, and 71.4%, respectively. Despite the high incidence of APA in FHF, these antibodies were not detected in most patients with acute or chronic hepatitis. There was a negative correlation between anti-CL-IgA and the platelet count, and a negative correlation between anti-PI-IgG and the amount of residual liver parenchyma. Our results suggest that APA develop secondarily to hepatocyte or sinusoidal cell damage and may aggravate both thrombocytopenia and liver failure.

Adult↗
PubMed1995

[Risk factors for pulmonary hypertensive crisis (PHC) following VSD repair in infants].

We examined 100 patients who had undergone VSD repair from 1988 to 1991 to determine the risk factors to induce PHC postoperatively. We analyzed age, weight, preoperative Pp/Ps, Rp/Rs, Qp/Qs, and postoperative Pp/Ps using discriminant analysis. We had 34 cases of pulmonary hypertension (PH: Pp/Ps > 0.7) preoperatively. Among 100 cases, PHC developed in 6 patients and 2 of them died postoperatively. Incidence of PHC in all patients was 6%, and that in patients with PH was 18%. PHC fatality rate was 33%. The analysis revealed that the occurrence of PHC was significantly higher among those whose ages were below 2.1 years, and with weight of under 9.85 kg, preoperative Pp/Ps > 0.73, Rp/Rs < 0.34, and postoperative Pp/Ps > 0.43. In those with preoperative PH, the risk for PHC increased significantly when their postoperative Pp/Ps exceeded 0.44.

Adolescent↗