Biomedical subjects

K Tabata

Publications and source records attributed to K Tabata.

At least 19 recordsLinked to original sources

PubMed1997

Evaluation of the efficacy of a 3.2% glutaraldehyde product for disinfection of fibreoptic endoscopes with an automatic machine.

The efficacy of 'Cidex Plus' 3.2% alkaline glutaraldehyde was evaluated for the disinfection of fibreoptic endoscopes. The glutaraldehyde concentration in 'Cidex Plus', stored in an automatic machine (Olympus EW-20), remained higher than 2% (2.21%) even after a total of 102 disinfection cycles during 28 consecutive days. The results of the in-vitro study on antimicrobial activity showed that this alkaline glutaraldehyde product had a greater activity against 20 test organisms, including vegetative bacteria, bacterial spores, mycobacteria, and fungi, than 2% glutaraldehyde alone. The presence of 10 or 30% human serum did not appear to affect the activity of glutaraldehyde adversely. Instrument samples made from a variety of materials such as stainless steel, glass, teflon, etc. were not damaged after 168 h of immersion in alkaline glutaraldehyde, although it contained approximately 1.7 times more glutaraldehyde than 2% glutaraldehyde alone. Based on these results, 3.2% alkaline glutaraldehyde is considered to be a more effective disinfectant for fibreoptic endoscopes, with the use of an automatic machine, than 2% glutaraldehyde.

Chemistry, Pharmaceutical↗

PubMed1996

Transmission of Helicobacter pylori infection via flexible fiberoptic endoscopy.

BACKGROUND: Public concern has been raised with regard to the possibility of transmission of instrument mediated Helicobacter pylori infection after upper gastrointestinal endoscopy. METHODS: Disinfection procedures for gastrointestinal endoscopes were surveyed in 20 Japanese institutions, and in vitro bactericidal activities of seven disinfectants against H. pylori were determined. RESULTS: Screening tests for infection before endoscopy were not consistently performed; only 11 institutions always screened for hepatitis B virus, nine for hepatitis C virus, and two for tuberculosis. All 20 institutions used the same flexible fiberoptic endoscope on more than one patient in succession, with minimal cleanings only. Only two used glutaraldehyde for disinfection. Most used ethyl alcohol, benzalkonium chloride, or alkyldiaminoethylglycine hydrochloride as an external wipe. Bactericidal testing of nine strains of H. pylori against disinfectants revealed that ethyl alcohol (80%) and glutaraldehyde (0.5%) killed all nine strains within 15 seconds, whereas chlorhexidine gluconate (0.05%, 0.1%), benzalkonium chloride (0.025%, 0.1%), alkyldiaminoethylglycine hydrochloride (0.1%), povidone-iodine (0.1%), and sodium hypochlorite (150 ppm) killed all nine strains within 30 seconds. CONCLUSION: H. pylori is readily killed by many common disinfectants and antiseptics. However, practices for disinfection of flexible fiberoptic endoscope were not appropriate.

Cross Infection↗

PubMed1996

Inhibitory effect of pentobarbital on biliary excretion of diclofenac in a rat liver perfusion system.

The effect of pentobarbital on the biliary excretion of diclofenac was investigated in a rat liver perfusion system following a pulse input of the drug. Without albumin in the perfusate, a trace amount of diclofenac was detected in the outflow from the liver (< 0.1%). The total biliary excretion of diclofenac (intact diclofenac plus its glucuronide) decreased from 23.8% (diclofenac 6.01, glucuronide 17.8%) to 16.3% (diclofenac 5.09, glucuronide 11.2%) with an increase in the perfusate concentration of pentobarbital from 0 to 2.5 micrograms mL-1. At pentobarbital concentrations exceeding 2.5 micrograms mL-1, the biliary excretion of diclofenac and its glucuronide (14% total diclofenac) was not reduced further. The mean local excretion times of both diclofenac and its glucuronide were approximately 17 min and were unchanged at all pentobarbital concentrations tested. The ratios of biliary excreted diclofenac and its glucuronide to total diclofenac were 22 and 78%, respectively, and these values were virtually constant at all concentrations of pentobarbital in the perfusate. These results suggest that the glucuronidation of diclofenac and the biliary excretion of its glucuronide are rapid processes and that pentobarbital blocks a step before glucuronidation.

Adjuvants, Anesthesia↗

PubMed1996

Influence of pentobarbitone on in-vivo local disposition of diclofenac in rat liver.

Because the liver is the main organ eliminating many drugs from the body and because pentobarbitone and other analogues can inhibit biliary secretion, the influence of pentobarbitone on hepatic local disposition of diclofenac has been investigated. Diclofenac was infused into the portal and femoral veins of non-anaesthetized rats (group A) and rats anaesthetized with pentobarbitone (group B) and the plasma concentration of diclofenac and the total amount of diclofenac excreted in the bile (in both cases intact diclofenac plus its glucuronide) were simultaneously monitored by HPLC at appropriate time intervals. The time-courses of plasma concentration and amount excreted in the bile were evaluated by moment analysis with trapezoidal integration. The hepatic recovery ratio (FH) was calculated by comparing the area under the curve (AUC) of plasma concentration after intravenous infusion with that after intraportal infusion. The mean biliary transit time (tb) was estimated by subtracting the mean residence time (MRT) of the plasma data from the mean biliary residence time (MRTb) of the biliary excretion data. The FH values of diclofenac were 0.664 in group A and 0.643 in group B. The biliary excretion ratio (Fb) of total diclofenac after intravenous administration was 27.0% in group A and 14.1% in group B. The tb values for total diclofenac were estimated to be 0.192 h (intravenous) and 0.159 h (intraportal) in group A, and 0.174 h and 0.238 in group B. Analysis of variance showed that differences among these four tb values were insignificant at the 5% level. The differences in the mean residence time (MRT), total clearance (CL) and distribution volume at steady state (Vss) were insignificant between groups A and B. Whereas total and the hepatic clearance of diclofenac were not affected by pentobarbitone, biliary clearance was extensively reduced. It took a relatively long time for diclofenac to move from the sinusoid into the bile and the time was not affected by pentobarbitone.

Adjuvants, Anesthesia↗

PubMed1996

Local absorption kinetics into the portal system using the portal-venous concentration difference after an oral dose of diclofenac in the awakening rat. Accelerative effect of bile on intestinal absorption of diclofenac.

The local absorption kinetics from the intestinal tract into the portal system was evaluated using the portal-venous concentration difference (P-V difference) after oral administration of diclofenac in conscious rats. The local absorption ratio (Fa), mean local absorption time (ta), and relative variance (sigma 2/ta2) from the intestinal tract into the portal system were estimated by simultaneously measuring the portal and venous concentrations, using diclofenac as a model drug. The effect of bile on diclofenac intestinal absorption was also investigated. The awakening rats simultaneously cannulated into the jugular and portal veins were divided into group A with intact enterohepatic circulation (EHC) and into another group with bile-duct cannulation to block EHC. The rats in the latter group were further divided into group B without the bile supply to the intestinal tract and into group C with the bile supply from the other rat. After oral administration of diclofenac to rats in groups A, B, and C, the portal and venous concentrations of diclofenac in each rat were simultaneously monitored by HPLC method at proper time intervals. The absorption time profile of diclofenac into the portal system was directly predicted from P-V difference. Plasma concentrations of diclofenac in the portal vein were constantly higher than those in the jugular vein after the oral administration. It was demonstrated that P-V difference was caused by absorption from the intestinal tract into the portal system. Fa in groups A, B, and C were estimated to be 91.5% for 8 hr, 33.8% for 3 hr, and 57.8% for 3 hr, respectively. ta in groups A, B, and C were estimated to be 2.26 hr, 0.65 hr, and 0.96 hr, respectively. sigma 2/ta2 in groups A, B, and C were 1.31, 0.48, and 0.55, respectively. Fa and ta of diclofenac extensively increased in the presence of the bile in the intestinal tract, whereas sigma 2/ta2 was unaffected by the bile. The mean absorption time (MAT) almost agreed with ta, which demonstrates that the mean transit time through the liver (tH) is negligible in MAT(= ta+tH).

Administration, Oral↗

PubMed1996

[A patient with thyroid carcinoma who developed consciousness disturbance during acyclovir administration for herpes zoster].

A 69-year-old man developed confusion and disorientation, following intravenous administration of acyclovir for herpes zoster at the right C5 area. His consciousness was disturbed four days after the beginning of acyclovir therapy (daily dose: 500 mg, every 12 h), and the symptoms resolved two days after cessation of acyclovir. Neuroradiological examination revealed no intracranial abnormality, and the routine CSF examination was within the normal range of values except for a mild elevation of IgG (7.4 mg/dl). An electroencephalogram showed diffuse slow activities without paroxysmal waves on admission, but the findings of electroencephalograms were gradually normalized in parallel with the recovery of consciousness. Fever, signs of meningeal irritation, involuntary movement or renal dysfunction were not observed during the course of illness. Although the serum concentration of acyclovir was not elevated, we considered the adverse effects of acyclovir had resulted in his consciousness disturbance. Acyclovir is greatly useful for herpes simplex and varicella-zoster virus infections, and its complications are extremely rare. However, several reports described various neuropsychiatric side effects in patients receiving acyclovir. Most of such cases had an association with severe renal failure or malignant tumor; actually, an intense malignancy surveillance over our case revealed thyrogenic papillary adenocarcinoma without metastasis. The excretion of acyclovir is mainly through the kidney, so that the neurotoxicity of acyclovir in cases with renal insufficiency stems from its excessive accumulation in the body. In malignancy complicated patients, on the other hand, some authors surmised about the influences from the co-use of other neurotoxic drugs or radiation therapy, but reasons for such conditions remain obscure. The neuropsychiatric manifestation caused by acyclovir is an entity distinguishable from viral encephalitis, and a careful surveillance for malignancy is required in such cases.

Acyclovir↗

PubMed1996

Clinical study of chronic tonsillitis with IgA nephropathy treated by tonsillectomy.

Over the past 5 years, bilateral tonsillectomy has been performed in 104 patients (48 male and 56 female) with IgA nephropathy at the Department of Otolaryngology of Sendai Red Cross Hospital. We studied the relationship between remission rates as shown by urinary findings at one year after tonsillectomy and various clinical factors. Patients with mild or moderate renal pathology had higher postoperative remission rates of proteinuria than those with advanced renal pathology. There was a tendency for higher remission rates in patients with smaller tonsils. There were no significant differences relative to past history of tonsillitis, age, pus plugs in the lacunae, temporary deterioration of urinary findings after tonsillectomy, and results of provocation tests.

Adolescent↗

PubMed1995

Evaluation of intestinal absorption into the portal system in enterohepatic circulation by measuring the difference in portal-venous blood concentrations of diclofenac.

PURPOSE: We evaluated the first-pass effects in vivo by the intestine and liver during enterophepatic circulation (EHC) by simultaneously measuring the portal and venous plasma concentrations of the rat. METHODS: The venous and upper portal blood vessels were cannulated through the jugular and the pyloric veins, respectively, to obtain simultaneously blood samples from both sites. After diclofenac was injected as a bolus through the jugular vein, the concentrations of diclofenac in the portal and jugular veins were measured at time intervals. The absorption rate from the intestinal tract into the portal system was determined using the portal-venous difference in plasma concentrations of diclofenac, considering 40% partitioning of diclofenac into erythrocytes. RESULTS: After one hour, the plasma concentration in the portal vein was always higher than that in the jugular vein in awakening rats with intact EHC (portal-venous blood concentration difference). No portal-venous difference was observed in awakening rats with bile-duct cannulation. Therefore, it was concluded that this portal-venous concentration difference was not due to the hepatic clearance but to diclofenac reabsorption from the intestinal tract. CONCLUSIONS: Approximately 40% of the dose of diclofenac was reabsorbed over 8 hours from the intestinal tract into the portal system. By comparing the reabsorbed amounts in the portal system and in the systemic circulation, the hepatic extraction ratio in vivo (FH) of diclofenac was estimated to be 63%.

Animals↗

PubMed1995

Epitope analysis using anti-oligosaccharide (G4) monoclonal antibody.

A murine monoclonal antibody recognizing (1-->6)-beta-D-glucopyranosyl laminaritriose (G4) was prepared by immunizing BALB/c mice with G4-bovine serum albumin conjugate and fusing the splenocytes with mouse myeloma cells. The monoclonal antibody (IgM) provoked by the cloned cells showed low reactivity with schizophyllan, an antitumor polysaccharide, but notable reactivity with some low-molecular-weight schizophyllans. This antibody was useful for determination of the epitope of several polysaccharides. The extent of reactivity of this monoclonal antibody was related only to the molecular weight of schizophyllan.

Animals↗

PubMed1995

Influence of laparotomy on disposition kinetics of diclofenac in CCl4-intoxicated rats.

The effect of the acute hepatic failure induced by CCl4 on the pharmacokinetics of diclofenac, which is definitely subject to enterohepatic circulation (EHC) in normal rats, was evaluated. This hepatic failure extinguished the secondary peak on the plasma time course which is usually observed in normal rats due to EHC. In the group without EHC by means of bile cannulation, the total clearance (CL) markedly decreased by CCl4-intoxication from 0.7 l/h/kg down to 0.1 l/h/kg, and mean residence time (MRT) increased from 0.29 h up to 2.8 h. The plasma time curves of the rats with laparotomy and with bile duct-cannulation were almost the same in the CCl4-intoxicated group. The bile excretion ratio of diclofenac markedly decreased by CCl4-intoxication from 43% down to 13%. In both groups, 92% of the total diclofenac excreted into the bile was glucuronide. While EHC made area under the curve (AUC) and MRT obviously increase in the CCl4-free rats, the effect of EHC on these moments was negligible in the CCl4-intoxicated rats. In the CCl4-intoxicated condition, the elimination of diclofenac in the rats with laparotomy was considerably slower than that in the rats without laparotomy. The plasma time courses were obviously monoexponential in the former group, while those were almost biexponential in the latter group.

Animals↗

PubMed1995

Water-soluble viscous substance of Jew's mellow leaves lowers serum and liver cholesterol concentrations and increases fecal steroid excretion in rats fed a high cholesterol diet.

The effect of Jew's mellow leaf powder and its water soluble viscous substance on cholesterol metabolism in rats fed a high cholesterol diet was examined. When compared to the controls, total serum and liver cholesterol concentrations were significantly decreased or tended to decrease in the groups given dry powder of fresh Jew's mellow leaves, dry powder purchased from the market or residual powder after extracting with ethanol, whereas no difference was observed in those given residual powder after extracting with water. There were significant increases or increasing tendencies in the fecal excretion of bile acids, total neutral sterols and cholesterol in those fed the experimental diets when compared to the control group. Rats fed a diet containing a water-soluble viscous substance (1.7%, about 1% as dietary fiber) obtained from the dry powder of Jew's mellow leaves showed significant decreases in serum and liver cholesterol concentrations and increases in fecal excretions of bile acids and neutral sterols. Based on the above, the component of dry powder of Jew's mellow leaves that is effective in decreasing serum and liver cholesterol concentrations was found to be a soluble dietary fiber, and the mechanism was assumed to be largely due to the increased excretion of bile acids and neutral sterols.

Animals↗

PubMed1994

Molecular cloning and sequence analysis of the proBA operon from an extremely thermophilic eubacterium Thermus thermophilus.

A 3.6 kb DNA fragment carrying the Thermus thermophilus proBA region, which encodes the first two steps in the proline biosynthetic pathway, was cloned from the Thermus thermophilus gene library, and its complete nucleotide sequence was determined. The deduced amino acid sequence of gamma-glutamyl kinase (40,657 Da), the product of proB gene, and gamma-glutamyl phosphate reductase (48,747 Da), the product of proA gene, showed 44.1% and 44.4% identity to those of Escherichia coli, respectively. The termination codon of the proB gene and the initiation codon of the proA gene overlapped by 2 bp. A possible transcriptional termination structure was found downstream of the proA gene but not downstream of the proB gene. These results indicate that the proBA genes of T. thermophilus form a single operon as in E. coli.

Aldehyde Oxidoreductases↗

PubMed1994

An antitumor, branched (1-->3)-beta-D-glucan from a water extract of fruiting bodies of Cryptoporus volvatus.

A water-soluble, (1-->6)-branched (1-->3)-beta-D-glucan (H-3-B) was isolated from a hot-water extract of the fruiting bodies of the fungus, Cryptoporus volvatus (Basidiomycetes). Enzymatic analysis using exo-(1-->3)-beta-D-glucanase and methylation analysis indicated that this polysaccharide has a main chain composed of beta-(1-->3)-linked D-glucopyranosyl residues, and single, beta-(1-->6)-linked D-glucopyranosyl residues attached as side chains to, on average, every fourth sugar residue of the main chain. This structure was confirmed by 13C NMR spectra of the glucan in Me2SO-d6. The weight-average molecular weight (Mw) of H-3-B was determined to be 44.0 x 10(4) by gel permeation chromatography equipped with a low-angle laser-light-scattering photometer. The electron microscopic observations showed that H-3-B and its sonicated sample (S-H-3-B, Mw = 13.7 x 10(4)) can be described as linear worm-like chains. The mass per unit length for native and sonicated H-3-B was determined to be 1750 and 1780 g mol-1 nm-1, respectively, from the contour lengths obtained by electron microscopy and the molecular weights. These values are in good agreement with that expected for the triple stranded structure. A sample denatured in 0.1 M NaOH and subsequently renatured by neutralization showed a mixture of linear and cyclic structures, and larger aggregates with less well-defined morphology. The H-3-B and S-H-3-B had antitumor activity against the Sarcoma 180 tumor.

Animals↗

PubMed1994

A carotenogenic gene cluster exists on a large plasmid in Thermus thermophilus.

In Thermus thermophilus HB27, the crtB gene encoding phytoene synthase was found to exist on the large plasmid, pTT27. One of the carotenoid under-producing mutants, Crt31, carried a derivative of pTT27 (pTT27') in which deletion and inversion were observed near the crtB gene. T. thermophilus HB8 also contained a large plasmid which showed homology to pTT27 and the crtB gene. These results suggested that genes for carotenoid biosynthesis occurred as a cluster on a large plasmid in Thermus thermophilus. This is the first report to show directly that carotenogenesis is plasmid-encoded in microorganisms.

Alkyl and Aryl Transferases↗

PubMed1994

Molecular cloning and sequence analysis of the proC gene encoding delta 1-pyrroline-5-carboxylate reductase from an extremely thermophilic eubacterium Thermus thermophilus.

A gene library of the extremely thermophilic bacterium, Thermus thermophilus HB27, was constructed in Escherichia coli, and recombinant plasmids able to complement proC mutants of HB27 were obtained. Using the plasmids, the complete nucleotide sequence of the proC gene encoding delta 1-pyrroline-5-carboxylate reductase (P5CR) [EC 1.5.1.2] was determined. The deduced amino acid sequence showed a significant homology to those of P5CRs of E. coli, soybean and human. The proC gene of T. thermophilus was expressed in E. coli and the activity of heat-resistant P5CR was determined. The mutation sites of two HB27 proC mutants were also determined.

Amino Acid Sequence↗

PubMed1994

An improved sandwich ELISA method for the determination of immunoreactive schizophyllan (SPG).

As it is important to determine the optimal serum concentration of schizophyllan (SPG) when it is used as an anti-cancer drug, we devised a solid-phase ELISA. We also developed a sandwich ELISA using murine anti-SPG monoclonal antibody as the first antibody and rabbit anti-SPG serum as the second antibody in order to improve the detection sensitivity. This assay was able to determine SPG concentrations over 1.0 ng/ml and the absorbance at 490 nm was directly proportional to the SPG concentration. SPG in rabbit serum, obtained after intravenous and intramuscular injection (SPG; 10 mg/kg), was determined by this sandwich ELISA. Furthermore, the sensitivity of this ELISA method was compared with that of the Limulus test. The Limulus test is able to detect SPG in physiological saline (pH 6.3) at concentrations greater than 1.0 microgram/ml, but the sensitivity increased when SPG was dissolved in alkaline solution (pH 12.0), enabling SPG to be measured almost down to 1.0 ng/ml. These data suggest that our sandwich ELISA may be used for the measurement of SPG in blood or tissue.

Animals↗

PubMed1994

Monoclonal antibody to proteoglycan derived from Grifola frondosa (Maitake).

A murine monoclonal antibody (MAb) was prepared by immunizing BALB/c mice with a proteoglycan fraction derived from Grifola frondosa (Maitake mushroom), followed by the hybridization of spleen cells with mouse myeloma cells. The MAb (subclass; Ig G2b), designated MPG2, reacted with schizophyllan (SPG), curdlan, scleroglucan, laminarin and lentinan, but not with dextran, pullulan, mannan and xylan. Immunohistochemistry (ABC-GO method) showed that MAb MPG2 reacted with lysosomal proteoglycan and (1-->6)-beta-branched laminaritriose taken up by rabbit peritoneal macrophages. These results suggest that this MAb may recognize mainly (1-->3)-beta-D-glucan, and may be useful for determining the immunological properties of Grifola frondosa-derived proteoglycan.

Animals↗

PubMed1994

The inhibitory effect of sulfated schizophyllans and related oligosaccharides on coagulation and fibrinolysis.

Sulfated schizophyllans and sulfated oligosaccharides were prepared and their inhibitory effects on coagulation and fibrinolysis were examined. Some sulfated schizophyllans, which had a sulfur content of more than 10%, prolonged prothrombin time (PT) and thrombin time (TT). Interestingly, some sulfated schizophyllans and related oligosaccharides were able to inhibit plasmin toward fibrinolysis and amidolysis.

Amino Acid Sequence↗