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Biomedical subjects

T Kaneda

Publications and source records attributed to T Kaneda.

At least 109 records · Page 6Linked to original sources
PubMed1994

Bacteriological evaluation of a new air turbine handpiece for preventing cross-contamination in dental procedures.

An autoclavable air turbine handpiece, Air Flushing Clean System (AFCS) (Osada Electric Co., Ltd., Tokyo, Japan) was developed for use in dentistry with the objective of reducing cross-contamination. Its potential for bacterial contamination was investigated in vitro using two bacterial strains (Streptococcus mutants ATCC 25175 and Staphylococcus aureus FDA 209 P). In theory, this device should prevent cross-contamination of the internal water and air lines of the handpiece, by maintaining an internal positive pressure even after the turbine is stopped. In the present study, this AFCS device was found to reduce the bacterial contamination within the air turbine handpiece more effectively than the conventional handpiece used according to accepted protocol. The reduction of such contamination by the AFCS is in keeping with the recent objective of the American Dental Association to reduce cross-contamination during dental procedures.

Bacteriological Techniques↗
PubMed1994

Development of hemopoietic bone marrow within the ectopic bone induced by bone morphogenetic protein.

Neogenesis of hemopoietic bone marrow was observed in the ectopic bone induced by implantation of bone morphogenetic protein (BMP) into the muscle of mice. A bone rudiment-like cartilage was formed first, which was then replaced by bone through an endochondral ossification process. Bone marrow formation occurred after the invasion of blood vessels into the cartilage, with accumulations of small lymphocyte-like cells and the appearance of large hemopoietic stem cells around the blood vessels. The stem cells proliferated and differentiated to form hemopoietic bone marrow. This process was similar to the embryogenesis of bone and bone marrow, but the hemopoietic activity of the BMP-induced bone was transient. The bone marrow was converted to fatty tissue within 2 weeks of its appearance. This study showed that implantation of BMP in the ectopic sites offers a useful model to investigate the neogenesis of ectopic bone marrow and the regulation of its activity.

Adipose Tissue↗
PubMed1993

Aromatization of 4-oxocyclohexanecarboxylic acid to 4-hydroxybenzoic acid by two distinctive desaturases from Corynebacterium cyclohexanicum. Properties of two desaturases.

We have previously demonstrated that Corynebacterium cyclohexanicum degrades cyclohexanecarboxylic acid, a bacteriocide, through a pathway including the aromatization of 4-oxocyclohexanecarboxylic acid to 4-hydroxybenzoic acid [Kaneda, T. (1974) Biochem. Biophys. Res. Commun. 58, 140-144]. Aromatization has now been shown to be catalysed by two desaturase enzymes. Under the action of desaturase I, 4-oxocyclohexanecarboxylic acid is converted to (+)-4-oxocyclohex-2-enecarboxylic acid which is then aromatized by desaturase II to 4-hydroxybenzoic acid. The latter reaction is presumed to occur via the unstable intermediate, 4-oxocyclohex-2,5-dienecarboxylic acid, which is spontaneously isomerized to 4-hydroxybenzoic acid. Desaturase I has been purified in an electrophoretically homogeneous form. It is monomeric with a molecular mass of 67 kDa and contains one tryptophan, one histidine and two cysteine residues per enzyme molecule. The enzyme produces an equivalent amount of 4-oxocyclohex-2-enecarboxylic acid and hydrogen peroxide from 4-oxocyclohexanecarboxylic acid. The properties of desaturase I have been studied in detail. Desaturase II is unstable and has been partially purified. Its characterization is therefore limited. However, the molecular mass of desaturase II was estimated to be 43 kDa by gel filtration chromatography. The characterization of both desaturase enzymes is described in this paper. The possible environmental importance of microbial aromatization in the biodegradation of compounds with the cyclohexane structure is discussed.

Amino Acids↗
PubMed1993

The primary structure of branched-chain alpha-oxo acid dehydrogenase from Bacillus subtilis and its similarity to other alpha-oxo acid dehydrogenases.

The bfmB mutant of Bacillus subtilis requires branched short-chain carboxylic acids for growth because the organism is known to be defective in branched-chain alpha-oxo acid dehydrogenase. The DNA in the region of bfmB has now been cloned and sequenced, and the gene has been analyzed. The results show that there are three open reading frames in the area, each of which is preceded by a putative ribosome binding site, and the last of which is followed by a putative transcription termination site with inverted repeats. The amino acid sequences deduced by analysis of the reading frames are highly similar (with 32-49% identity) to the E1 alpha, El beta and E2 components of pyruvate, 2-oxoglutarate and branched-chain alpha-oxo acid dehydrogenases from different sources. The thiamin diphosphate binding, putative subunit interaction and phosphorylation sites of the E1 alpha of four reported branched-chain alpha-oxo acid dehydrogenases from different sources are very similar to those of the first open reading frame (E1 alpha) of bfmB. A similar result is also obtained with the lipoyl-binding site (lysine) and its domain of the E2 component of alpha-oxo acid dehydrogenases from different sources. The present data, along with the reported biochemical data, lead to the conclusion that bfmB encodes a branched-chain alpha-oxo acid dehydrogenase, which is composed of E1 alpha, E1 beta and E2 genes. This organization is identical to that of the 2-oxoglutarate dehydrogenase in B. subtilis.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1993

Effects of hypoxia on the use-dependent inhibition of conduction velocity induced by cibenzoline in guinea pig ventricular myocardium.

The use-dependent effects of cibenzoline, a new anti-arrhythmic drug, on the maximal rate of rise (Vmax) of the action potential and on conduction velocity, and their corresponding recovery kinetics were studied in isolated papillary muscles of guinea pigs under normal and hypoxic conditions. Standard microelectrode techniques were applied to monitor the action potential of the muscles and their conduction. Under control conditions, the amount of use-dependent block of Vmax, conduction velocity, and square of conduction velocity, induced by 10 mumol/L cibenzoline were 26.5 +/- 3.9, 13.8 +/- 1.4, and 25.6 +/- 2.4%, respectively; under hypoxic conditions, these values increased to 32.3 +/- 4.8, 19.7 +/- 1.2, and 35.5 +/- 2.0%, respectively. In the presence of 10 mumol/L cibenzoline, the mean values of time constants for the onset of the use-dependent inhibition of Vmax, conduction velocity, and the square of conduction velocity, during a 2-Hz stimulation, were 3.65 +/- 0.27, 2.77 +/- 0.33, and 2.56 +/- 0.26 seconds, respectively. Under hypoxic conditions, these values changed to 5.10 +/- 0.96, 3.05 +/- 0.44, and 2.84 +/- 0.39 seconds, respectively. The recovery time constants averaged 14.72 +/- 4.08 seconds (for Vmax), 22.23 +/- 3.78 seconds (for conduction velocity), and 23.17 +/- 13.38 seconds (for the square of conduction velocity) in the presence of 10 mumol/L cibenzoline, and 17.19 +/- 8.59 seconds (for Vmax), 15.77 +/- 2.37 seconds (for conduction velocity), and 16.82 +/- 2.61 seconds (for the square of conduction velocity) under hypoxic conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Effect of ATP on the release of hsp 70 and hsp 40 from the nucleus in heat-shocked HeLa cells.

We have recently found a novel 40-kDa heat-shock protein (hsp 40) in mammalian and avian cells and reported that the N-terminal amino acid sequence of mammalian hsp 40 has homology with the bacterial DnaJ heat-shock protein. Also, hsp 40 has been shown to be translocated from the cytoplasm into the nuclei/nucleoli by heat shock and colocalized with hsc 70 (p73) in the nucleoli of exactly the same cells. We here investigated the effect of ATP on the release of hsp 70 (both constitutive p73 and inducible p72) and hsp 40 from the nuclei/nucleoli of heat-shocked HeLa cells which were permeabilized with Nonidet-P40 using immunofluorescence and immunoblotting. Hsp 70 in the nucleoli was released by the addition of ATP but not by ADP, GTP, nonhydrolyzable ATP, nor high salt buffer. In contrast, hsp 40 was not released from the nucleoli with any of these treatments or any combination of these treatments. Thus, hsp 40 might dissociate spontaneously from the nucleoli after hsp 70 has been released in an ATP-dependent manner. Using cell fractionation methods, we showed that while the majority of hsp 40 is localized in the cytoplasm, a small portion of it is located in the microsome fraction in non-heat-shocked control cells and in cells which recovered from heat shock.

Adenosine Triphosphate↗
PubMed1993

Type selective inhibition of microbial fatty acid synthases by thiolactomycin.

The antibiotic, thiolactomycin, is known to selectively inhibit the Type II straight-chain fatty acid synthase (monofunctional enzyme system, e.g. Escherichia coli enzyme) but not Type I straight-chain fatty acid synthase (multifunctional enzyme system, e.g. Saccharomyces cerevisiae enzyme). We have studied the effect of thiolactomycin on the branched-chain fatty acid synthases from Bacillus subtilis, Bacillus cereus, and Bacillus insolitus. Fatty acid synthase from all three Bacilli was not inhibited or only slightly inhibited by thiolactomycin. E. coli synthase, as expected, was strongly inhibited by thiolactomycin. Branched-chain fatty acid synthase from Bacillus species is a monofunctional enzyme system but, unlike Type II E. coli synthase, it is largely insensitive to thiolactomycin.

Anti-Bacterial Agents↗
PubMed1993

Phosphatidylcholine peroxidation and liver cancer in mice fed a choline-deficient diet with ethionine.

A high incidence of hepatocellular carcinoma (HCC) was observed in mice fed a choline-deficient diet containing 0.1% ethionine (CDE) for 19 months. HCC was present in 85% of CDE mice and in 22% of choline-deficient (CD) mice not receiving ethionine. This strong hepatocarcinogenicity of the CDE diet was concomitant with a severe decrease in plasma and liver alpha-tocopherol (Toc) to 60 and 35%, respectively, of those contained in choline-supplemented (CS) control mice. We previously found that this dietary-induced HCC was preceded at 4-week feeding by a depletion of Toc and a remarkable increase of phosphatidylcholine hydroperoxide (PCOOH) in the livers of CDE mice. When HCC was prominent in CDE mice, PCOOH was still elevated. Mouse glutathione S-transferase (GST) M II isozyme, which is related to rat GST-P form, a positive marker for rat hepatic preneoplastic and neoplastic lesions, revealed an inverse histochemical pattern as that seen in rats (i.e., the HCC lesions tended to decreased staining). The aforementioned results taken together indicate that decreases in Toc and enhanced PC peroxidation are important events in CDE-induced mice liver tumors.

Animals↗
PubMed1993

The relationship between collagen metabolism and temporomandibular joint osteoarthrosis in mice.

The histologic changes in the temporo mandibular joint (TMJ) and the activity of serum collagenase-like (CL) peptidase and prolyl endopeptidase (PEP) were compared in mice with spontaneous osteoarthrosis (C57 black mouse/6 Silverberg (C57BL/6S) and control mice (C57 black mouse/6N (C57BL/6N) and ddY). The onset of osteoarthrosis of the TMJ in the C57BL/6S mice was noted at 12 weeks of age. Clefting in the chondrocyte layer was noted at 24 to 36 weeks of age; chondrocyte cluster and pannus at 36 to 60 weeks of age; and clefts deep in the bone and formation of osteophytes at 72 to 96 weeks of age. CL-peptidase and PEP activity significantly higher in C57BL/6S mice than in osteoarthrosis-free C57BL/6N and ddY mice. These changes occurred at an earlier age than the histologic changes. The findings suggest that these enzymes may play a significant role in the onset of osteoarthrosis in joints.

Animals↗
PubMed1993

Crucial role of serum human chorionic gonadotropin for the aggravation of thyrotoxicosis in early pregnancy in Graves' disease.

Thyrotoxicosis in Graves' disease is often aggravated in early pregnancy and is closely associated with postpartum recurrence of stimulative thyrotoxicosis. To examine whether thyroid-stimulating TSH receptor antibody (TSAb) or human chorionic gonadotropin (hCG), which also has thyroid-stimulating activity (TSA), was responsible for this early aggravation, the respective TSA due to TSAb or hCG was evaluated by a highly sensitive cAMP accumulation assay using FRTL-5 cells. TSA was detectable in all of 11 women in normal early pregnancy, correlated positively with serum hCG concentration, and was abolished completely by the pretreatment of serum sample with the solid-phase hCG antibody coupled with Sepharose 4B. The model serum samples of Graves' disease with pregnancy were made by the mixture of normal pregnant and Graves' sera, and their TSA were reduced by the pretreatment with the solid-phase hCG antibody, just corresponding with the reduction in hCG-induced TSA. TSA of early pregnant sera in 20 patients with Graves' disease decreased significantly but were still positive even after the pretreatment with the hCG antibody. Serial changes in TSAb and hCG-induced TSA were measured in 5 of these 20 pregnant patients. hCG-induced TSA increased associated with the increase in free thyroxine, while TSAb did not show striking change in early pregnancy. These data indicate that (1) respective TSA due to TSAb or hCG can be measured distinctively by using the solid-phase hCG antibody and (2) hCG plays a crucial role in the aggravation of Graves' thyrotoxicosis in early pregnancy.

Autoantibodies↗
PubMed1993

Irradiation effects on wound contraction using a connective tissue model.

To analyze irradiation effects on wound contraction, fibroblasts harvested from human oral mucosa were irradiated (single 2-, 4-, 6-, 8-, and 10-Gy exposures of x-rays). The irradiated fibroblasts were examined for growth ability, and they were cultured three-dimensionally in hydrated collagen gels. The irradiation inhibited growth of fibroblasts and contraction of collagen gels in a dose-dependent manner. In addition, inhibition depended on the duration after exposure. The organization of actin filaments of fibroblasts in this model was examined with fluorescent dye-conjugated phalloidin. Many elongated cell projections were formed in cells of the control group, but the cell projections were almost disrupted in the irradiated cells. X-ray irradiation is thus shown to inhibit wound contraction by affecting the organization of actin filaments in fibroblasts.

Actins↗
PubMed1993

Genetic mapping of bfmA mutation causing fatty acid deficiency in Bacillus subtilis.

Bacillus subtilis strain 626, defective in the bfmA gene, is a derivative derivatives of B. subtilis strain 168 and requires branched short-chain carboxylic acids for growth. Branched-chain 2-keto acid decarboxylase activity and fatty acid synthesis in B. subtilis strain 626 were 14 and 7%, respectively, of their levels in strain 626-2R, a spontaneously reverted strain. These results indicate that the bfmA mutation is in either the branched-chain 2-keto acid decarboxylase gene itself or its controlling gene. Thus, primer synthesis from the 2-keto acid substrate in strain 626 is defective, causing a deficiency in fatty acid synthesis. A bfmA mutation was transferred to a suitable genetic background and analysed. The bfmA strain, CAC1, was competent and motile, and required 50 microM CaCl2 or 5 microM FeCl3 for growth on glucose minimal agar plates. The bfmA gene was mapped between glyC (320 degrees) and ctrA (325 degrees) and estimated to be at 320 degrees by protoplast fusion and PBS1 phage transduction.

Bacillus subtilis↗
PubMed1993

A stress-inducible 40 kDa protein (hsp40): purification by modified two-dimensional gel electrophoresis and co-localization with hsc70(p73) in heat-shocked HeLa cells.

We have previously reported that a novel 40 kDa protein is induced by heat shock and several environmental stresses in mammalian and avian cells and that the N-terminal amino acid sequence of this 40 kDa protein has homology with the bacterial DnaJ heat-shock protein. We have purified this protein (40 kDa heat-shock protein, hsp40) from HeLa cells by modified two-dimensional gel electrophoresis and generated a polyclonal antibody against hsp40. This antibody was highly specific for human hsp40 and cross-reacted weakly with rat and Chinese hamster hsp40. Indirect immunofluorescence revealed that the hsp40 in HeLa cells accumulates in the nucleus, especially in the nucleolus, during heat shock and returns to the cytoplasm during the recovery period. The kinetics of the accumulation in the nucleoli and subsequent return to the cytoplasm of hsp40 was similar to that of hsp70. In addition, hsp40 was co-localized with hsc70(p73) in heat-shocked HeLa cells as demonstrated by double immunofluorescence staining. These results suggest that hsp40 (a DnaJ homologue) and hsp70 (a DnaK homologue) may act in concert to repair (refold) denatured proteins and protein aggregates in the nuclei and nucleoli of heat-shocked HeLa cells.

Cell Nucleolus↗
PubMed1993

[Effect of hydronephrosis on the contralateral blood flow and glomerular volume].

We designed a following experiment to appraise the effect of unilateral hydronephrosis on the contralateral kidney using weanling rats whose kidneys were in a growing stage. Rats were divided into 4 groups. Complete unilateral (left) ureteral obstruction (CUUO) was made on the experiment rats, and these went through the following procedures on the day 3 after CUUO; 1) Group R: CUUO released, 2) Group N: left nephrectomy performed, 3) Group S: CUUO continued. Sham-operations were performed on the days 0 and 3 to the controls. Renal cortical blood flow and glomerular volume of the contralateral (right) kidneys were determined on the days 5, 7, 9, 14 and 21. Blood flow to the renal cortex per unit volume (ml/min/100 cm3; measured with Laser blood perfusion monitor) in the contralateral kidneys increased gradually in the all groups, but statistical significance was not confirmed in the observed period between any groups. Increases in total renal blood flow (wet kidney weight times renal cortical blood flow per unit volume; g x ml/min/100 cm3) were proportional to the measured wet kidney weight in the all groups. Notably in the group N, a significant increase was noted compared to the group R and the controls. Glomerular volume (GV) of the contralateral kidneys did not show significant changes on the day 3 compared to the controls. GV significantly grew up during the day 5 to the day 14 (2 to 11 days after the relief of CUUO) in the group R and then it settled to the level of the controls on the day 21.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Renal function of contralateral kidney after total or partial removal of kidney with ectopic ureter].

The effects of partial or total removal of the kidney with ectopic ureter on the contralateral kidney were evaluated using DMSA renal uptake rate on 8 patients. After partial nephrectomy on 6 cases, the affected residual kidneys showed significant decrease in DMSA renal uptake rate in 2 cases in which the extirpated kidneys had normal renal tissue in part but did not show significant change in DMSA uptake rate in 4 cases in which the extirpated kidneys were dominated mainly with dysplasia. Post-operative increase in DMSA uptake rate of the contralateral kidneys were significant in 3 of 4 patients who had the operation before they became 2 years old. In 2 of these 3 cases, pre-operative scintigram showed extremely low rate of DMSA renal uptake. Four cases aged 2 years old and over did not show post-operative increase in the uptake rate. As we have previously reported on the cases with hydronephrosis, these results suggest that 1) existence of obstruction caused by ectopic ureter inhibit the development of the contralateral kidney and 2) the growth of the kidney can resume the release of that obstruction, if the release is made while the kidneys are still in developing stage.

Child↗
PubMed1993

[Studies on reflux nephropathy--renal tubular and glomerular damage evaluated by various urinary indices].

Measurements were performed on beta 2-microglobulin (beta 2-MG), alpha 1-microglobulin (alpha 1-MG), N-acetyl-beta-D-glucosaminidase (NAG) as indices of renal tubular damage and microalbumin as an index of renal glomerular damage in 204 cases with primary vesicoureteral reflux (VUR). Investigations were made on the relationship between each index and extent of renal cortical damage from the findings of 99mTc-dimercapto-succinic acid (DMSA) renoscintigraphy, and also on the changes of each index before and after antireflux operation. At the first examination, high values of urinary beta 2-MG, alpha 1-MG, NAG and albumin were noted in 36%, 40%, 50% and 34% of cases with VUR respectively. Almost all the cases with high indices values before the operation showed improvement in those values accompanied with disappearance of VUR after the operation. These findings suggest that renal tubular and glomerular damage were induced by the sterile reflux itself. High values of urinary indices were confirmed in 16% (beta 2-MG), 40% (alpha 1-MG), 27% (NAG) and 32% (albumin) cases after a lapse of 2 years or longer since antireflux operation or spontaneous disappearance of VUR. In some of these cases indices values showed some improvement but have not returned to normal levels, and in other cases indices were within normal limits preoperatively but turned out to be high levels during the observation period even after the disappearance of VUR. Most of these cases were accompanied with severe cortical damage of unilateral or bilateral kidneys on DMSA renoscintigraphy. Based on these findings, we suggest that overload to residual nephron, caused by reduced mass of functional nephron, is playing an important role on raising the values of various urinary indices.

Acetylglucosaminidase↗