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Biomedical subjects

K Adachi

Publications and source records attributed to K Adachi.

At least 397 records · Page 22Linked to original sources
PubMed1992

[Clinical spectrum of antibiotic associated enterocolitis due to methicillin resistant Staphylococcus aureus].

Historically, various types of antibiotic-associated diarrhea have been recognized. In the 1950-1960s, multi-resistant Staphylococcus aureus was implicated to be major cause of antibiotic-associated diarrhea, especially pseudomembranous enterocolitis. In the late 1970s, a new type of antibiotic-associated diarrhea, which is characterized by pseudomembranous colitis and lack of fecal multi-resistant S. aureus, usually following lincosamide administration, was recognized. Many studies have revealed the pathogenic roles of Clostridium difficile in these patients. Recent emergence of methicillin resistant S. aureus (MRSA) provokes another type of antibiotic-associated diarrhea. We have tried to isolate S. aureus and C. difficile from 150 faecal samples of patients with antibiotic-associated diarrhea. S. aureus alone was isolated from 32 (21.3%) samples. C. difficile alone was isolated from 51 (34.0%) samples, and, both were detected in 23 (15.3%) samples. 90.9% of S. aureus were MRSA. Comparing the clinical features of these cases, patients with both C. difficile and MRSA showed more serious clinical features. The patients who had undergone laparotomy were accompanied by shock and meteorism, more often than patients without laparotomy. The management of antibiotic-associated diarrhea due to MRSA is discussed.

Aged↗
PubMed1992

Isolation and some biochemical properties of porcine pancreas mitochondria.

Morphologically and functionally intact mitochondria were isolated from the porcine pancreas using a conventional, differential centrifugation method. The homogenate of the porcine pancreas made in a medium containing 0.25 M sucrose, 10 mM Tris-Cl, pH 7.4, 0.5% bovine serum albumin and 1 mM EDTA, in the presence or in the absence of dibucaine and trypsin inhibitor, was centrifuged for 10 min at 700xg. The supernatant was centrifuged for 10 min at 7000xg, and the pellet was washed three times. Trypsin activity of mitochondria isolated in the absence of dibucaine and trypsin inhibitor was as low as that of mitochondria isolated in the presence of dibucaine and trypsin inhibitor, and a major part of the activity remained inactivated. Phospholipase A2 activity of the former mitochondria was as low as that of the latter, and remained unchanged up to 8-10 hr at 4 degrees C. The presence of bovine serum albumin and EDTA in the respiration medium was absolutely required to obtain good respiratory controls of those mitochondria. These data suggest that well-coupled mitochondria can be obtained from the pancreas by a conventional isolation procedure without activating the major part of trypsin.

Animals↗
PubMed1992

[Influence of an interlocking condition on the fracture healing process].

In order to clarify the influence of interlocking condition on the fracture healing process, the following three studies were carried out. First, an axial loading test was done in which an interlocking nail was inserted into a osteotomised human femoral bone. As a callus substitute, several kinds of resin were packed into the osteotomy gap. Load-formation curves were detected with strain gauges. These experiments suggest that the strain of the fractured end and its substitutes increase as the stiffness of the substitutes increases. Next, three weeks after the fixation with an interlocking nail of the osteotomized rabbit femur, the half of the femora were dynamized. The other half were not. Four to 56 weeks after osteotomy, the femora were harvested for radiographical and histological examination. No significant differences were detected between the two groups. In the last study, static and dynamic condition models similar to the second experiment were made. At 12 weeks, femora were harvested and measured for maximum bending strength. There were no statistically significant differences. These studies suggest that a so-called static condition has no unfavorable effects on fracture healing.

Animals↗
PubMed1991

Vitamin E deficiency has a pathological role in myocytolysis in cardiomyopathic Syrian hamster (BIO14.6).

This study revealed the occurrence of vitamin E deficiency in the myocardium of 60-day-old Syrian cardiomyopathic hamsters (BIO14.6), and that this deficiency might be related to the increase in lipid peroxide. Vitamin E administration for ten days effectively restored creatininekinase activity and decreased the lipid peroxide content in the myocardium, returning these to normal control levels (F1b). These results indicate that vitamin E deficiency, possibly combined with oxidative stress in the early cardiomyopathic stage plays an important role in initiating the pathogenesis of myocardial lesions.

Animals↗
PubMed1991

Absence of the human retinoblastoma gene product in the megakaryoblastic crisis of chronic myelogenous leukemia.

The human retinoblastoma gene (RB) product, which is involved in the control of cell cycle and tumor suppression, is constitutively expressed as a nuclear phosphoprotein in normal human cells. We examined leukemic cells from 22 patients with blast crisis of chronic myelogenous leukemia (CML) for alterations of the RB expression. Western blotting and flow cytometry with anti-RB-protein antibodies showed that all of five cases with megakaryoblastic crisis lacked the expression of the RB-encoded protein, whereas none of 17 cases with the other phenotypes such as myeloblastic or lymphoblastic crisis showed any abnormality. These findings suggest that megakaryoblastic transformation of CML might be lineage-specifically associated with loss of the RB protein.

Base Sequence↗
PubMed1991

Polymerization and solubility of Ni(II)-Fe(II) hybrid Hb S.

Polymerization of half-liganded Hb S was investigated using Ni(II)-Fe(II) hybrid Hb S, in which heme in either alpha or beta s subunits is replaced by Ni (II) protoporphyrin IX. Studies on the polymerization of these hybrid hemoglobins were carried out under aerobic conditions. Both alpha 2 (Ni) beta 2s (Fe-CO) and alpha 2 (Fe-CO) beta 2s (Ni) polymerized with a distinct delay time as do native deoxy-Hb S and Ni(II) Hb S. However, the critical concentration for polymerization of half-liganded Hb S, alpha 2 (Ni) beta 2s (Fe-CO) and alpha 2 (Fe-CO) beta 2s (Ni), was 4- and 8-times higher, respectively, than that of Ni(II)-Hb S. Kinetics of polymerization of both deoxygenated hybrid hemoglobins with CO completely removed were the same, although the critical concentrations for polymerization were intermediate between those for deoxy-Hb S and Ni(II)-Hb S. These results suggest that the small tertiary conformational change associated with the doubly liganded state may be much less favorable to polymerization than the completely unliganded state of Hb S. The conformational change depends on whether alpha or beta chain is liganded. The ease of polymerization and low solubility of sickle hemoglobin is dependent not only on quaternary, but on tertiary structural changes, as well as on the substitution of Val for Glu at the beta 6 position.

Hemoglobin, Sickle↗
PubMed1991

Measurement of plasma free steroids by direct radioimmunoassay of ultrafiltrate in association with the monitoring of free components with [14C]glucose.

We describe a modified method of centrifugal ultrafiltration using the Grace MPS-3 device for the measurement of plasma free (unbound) steroids (cortisol, testosterone, estradiol, and prednisolone). Plasma was incubated with [14C]glucose to monitor the movement of free components, applied to the MPS-3 and centrifuged. Steroid concentration of ultrafiltrate was directly measured by radioimmunoassay, and multiplied by the ratio of [14C]glucose count (dpm) in plasma to [14C]glucose count (dpm) in ultrafiltrate. The data by this method correlated well with those obtained by equilibrium dialysis. Our results of free steroid in healthy volunteers and patients with various diseases were comparable with the previously reported values. This procedure showed the advantages of small sample volume, rapid separation and the ability to process a large number of samples in a single run.

Adolescent↗
PubMed1991

Metal-tetracycline/H+ antiporter of Escherichia coli encoded by a transposon Tn10. Histidine 257 plays an essential role in H+ translocation.

The transposon Tn10-encoded tetA gene product is a metal-tetracycline/proton antiporter (Yamaguchi, A., Udagawa, T., and Sawai, T. (1990) J. Biol. Chem. 265, 4809-4813). Its tetracycline transport activity was inhibited by a histidine-specific reagent, diethyl pyrocarbonate. Among five histidine residues in this antiporter, only His257 is located in the putative transmembrane helices. Thus, His257 was replaced by Glu or Asp. Inverted vesicles containing the Glu257 and Asp257 mutant proteins showed only 20 and 10% of the tetracycline uptake of wild-type vesicles, respectively. In contrast to wild-type vesicles, the mutant vesicles showed no tetracycline-dependent proton translocation, indicating that the mutant proteins had lost the tetracycline/H+ antiport activity. The significant 60Co2+ uptake without proton translocation by the mutant vesicles also confirmed that the mutant carriers act as uniporters of a metal-tetracycline complex. The metal-tetracycline uniport by the mutant proteins was not inhibited by diethyl pyrocarbonate, indicating that His257 is the only histidine residue essential for proton translocation. These mutant proteins conferred about half-level resistance to tetracycline, probably due to their catalyzing downhill efflux of a metal-tetracycline complex out of the cells.

Amino Acid Sequence↗
PubMed1991

The pharmacokinetics of plasma total and free prednisolone during an alternate-day regimen.

To determine the pharmacokinetic changes of prednisolone associated with an alternate-day regimen, 12 patients with various diseases were studied longitudinally. There were 9 patients (6 with systemic lupus erythematosus, 2 with sarcoidosis and one with polymyositis), who were treated with prednisolone (daily period) and subsequently put on an alternate-day regimen (alternate-day period). In 2 of the other patients (one with systemic lupus erythematosus and one with multiple sclerosis), the alternate-day regimen was preceded by the daily regimen, and subsequently an intermittent regimen consisting of 4 consecutive days on therapy and 3 days off therapy was followed. In the remaining patient with systemic lupus erythematosus, the treatment with the alternate-day regimen was initiated and followed throughout the treatment period. The mean duration and the mean total administered dose during the study were 1.1 months and 1.9 g in the daily period, and 7.8 months and 7.7 g in the alternate-day period. The test was done and blood was drawn for 6 hours after an intravenous administration of 20 mg prednisolone (0.36 mg/kg on the average) at the end of the respective regimen periods. In the daily period and the on-day of the alternate-day regimen, the pharmacokinetic study of iv prednisolone injection was done before the ingestion of oral prednisolone. The off-day test was done the next morning of the on-day. Plasma total and free prednisolone concentrations were measured by RIA. On-day and off-day tests in the alternate-day period were performed during the same week. The mean half life of both total and free prednisolone was prolonged significantly in the daily period and during the on-day and off-day of the alternate-day regimen compared with the pretreatment values. The mean metabolic clearance rates (MCR) of both total and free prednisolone decreased significantly in the daily period and during the on-day and off-day of the alternate-day period in comparison with the pretreatment values. No significant difference was found between either mean half life or MCR during the on-day and off-day of the alternate-day period. These findings were in contrast with our previously observed prednisolone pharmacokinetics during the intermittent regimen (4 days on therapy and 3 days off therapy within one week), in which pharmacokinetic parameters during the on-day (after 3 days of prednisolone ingestion) and off-day (after 3 off-days of prednisolone ingestion) periodically changed and were similar to those in the pre-treatment period and during the daily therapy period, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

Indomethacin inhibition of middle ear bone resorption.

Localized osteoclastic bone resorption is responsible for the pathological changes within the middle and inner ear, which result in hearing loss and vertigo in chronic otitis media and otosclerosis. The local control of osteoclastic bone resorption is incompletely understood. Various small, locally active molecules, cytokines, have been shown to affect resorptive processes. Additionally, prostaglandins and their inhibitors have been shown to modulate the resorptive process in a number of in vitro studies. In this study, indomethacin, a cyclooxygenase inhibitor, was tested in a model of localized bone resorption, the pressurized gerbil bulla. After the experimental period, indomethacin was found to inhibit the number of osteoclasts and the resorptive area on the inner surface of the bulla. Therefore, it is likely that endogenous cyclooxygenase metabolites are intermediates in the sequence of cellular events, which results in localized bone resorption as in some systemic models.

Animals↗
PubMed1991

Androgen regulation of a specific gene in hamster flank organs.

Flank organs of Golden Syrian hamster containing large sebaceous glands are a useful model for studying androgen-dependent gene expression. Recently, we have isolated an androgen-dependent gene from a cDNA library constructed from male mRNAs of flank organs. In the present study, using this gene as a probe, we examined the kinetics of loss and re-expression of the mRNA of this gene. Dot blot hybridization, the current method, can approximately quantify mRNA levels. Castration caused a marked decrease in the mRNA within a few days to undetectable levels. Topical application of testosterone re-activated the mRNA levels, with the earliest activation within 24 h. The results of various topical steroid applications showed a full re-activation of the mRNA by testosterone and dihydrotestosterone, partial re-activation by androstanedione and androstenedione, and no activation by androstanediol or dehydroepiandrosterone. Simultaneous application of testosterone and progesterone inhibited the expression of mRNA but application of dihydrotestosterone and progesterone did not. The current dot blot hybridization technique appears to be a more direct approach for studying androgen action on DNAs than other previously used methods such as morphometry or enzyme assay.

Androgens↗
PubMed1991

Isolation and characterization of cDNA for an androgen-regulated mRNA in the flank organ of hamsters.

Flank organs of hamster are useful for studying androgen-dependent growth of hair follicles and sebaceous glands. To elucidate the mechanism of gene expression regulated by androgen, we constructed a cDNA library from flank organs of male hamsters and screened by a differential hybridization method using cDNA probes from normal and castrated males. We isolated a cDNA clone, termed FAR-17a, whose expression was found to be highly sensitive to androgen. FAR-17a mRNA of 1.8 kb was reduced after castration and reappeared after testosterone treatments. Among several tissues examined, FAR-17a gene was expressed at a high level in flank organ and a low level in testis and earlobe. FAR-17a probe detected a few fragments in genomic DNA of hamster, mouse, suncus, pig, and human, suggesting that this gene is phylogenetically conserved. The sequence of FAR-17a cDNA predicts a protein of 231 amino acids (27,216 daltons) having basic properties. The deduced protein has no significant homologies to proteins previously described.

Amino Acid Sequence↗
PubMed1991

Effects of alkyl alcohols and related chemicals on rat liver structure and function. I. Induction of two distinct types of megamitochondria.

The effects of alkyl alcohols and related chemicals on the ultrastructure of mitochondria in the rat hepatocyte were studied. The following three different groups of chemicals were tested: Group 1: alkyl alcohols with straight carbon chains (ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-octanol, 1-dodecanol and 1-octadecanol); Group 2: tert- and cyclo-compounds (tert-butanol, cyclo-pentanol, and cyclo-hexanol); and Group 3: polyhydroxy alcohols (ethylene glycol, propylene glycol, 1, 3-propanediol, glycerol and pentaerythritol). Results obtained were summarized as follows: 1) Ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-octanol had essentially the same effects on the mitochondrial ultrastructure: a mixed population of small and enlarged mitochondria with poorly developed cristae; 1-dodecanol induced ultrastructural changes of mitochondria of two distinct types: a mixed population of small and enlarged mitochondria with poorly developed cristae in some hepatocytes and remarkably enlarged mitochondria with well-developed cristate in others; and 1-octadecanol induced remarkably enlarged mitochondria in all hepatocytes. 2) Chemicals belonging to group 2 and group 3 induced essentially the same changes as those induced by 1-octadecanol. More than one month was required to induce those changes. The mechanism by which those ultrastructural mitochondrial changes were induced is not clear, but the present results may suggest that the hydroxy group (-OH) common to all these chemicals in some way accounts for the phenomenon.

1-Butanol↗
PubMed1991

Effects of alkyl alcohols and related chemicals on rat liver structure and function. II. Some biochemical properties of ethanol-, propanol- and butanol-treated rat liver mitochondria.

Functional changes of mitochondria in the liver obtained from rats given 32% ethanol, 32% propanol and 6.9% butanol in drinking water for up to 3 months were investigated. Animals were also fed a liquid diet containing ethanol for comparison. Results obtained were as follows: 1) Animals given ethanol in drinking water consumed twice as much ethanol daily as those fed a liquid diet containing ethanol, while ultrastructural changes of hepatic mitochondria were essentially the same between the former and the latter animals: the co-existence of megamitochondria and small mitochondria with poorly developed cristae. 2) Effects of alkyl alcohols tested on the respiratory rates and coupling efficiency of mitochondria were variable, depending on the kind of alkyl alcohols, the duration of experiments and oxidizable substrates used. 3) There was essentially no difference between the heavy and the light mitochondrial fractions obtained from alkyl alcohol-treated rat livers in terms of respiratory rates and coupling efficiencies. 4) Decreases in the content of cytochrome aa3 and the activity of activity of cytochrome oxidase, and increases in MEOS activity were most distinct in ethanol-treated rat livers. A possible role of chronic relative oxygen deficiency inside the hepatocyte caused by the metabolization of alkyl alcohols is discussed in order to interpret such peculiar ultrastructural changes of mitochondria.

1-Propanol↗
PubMed1991

[Effect of XKJ-001, a crude drug preparation, on body water distribution and water excretion in mice].

The effect of XKJ-001, a crude drug preparation based on Seisho-ekki-to, was investigated on the hematocrit, plasma volume, extracellular and interstitial fluid volumes as well as water excretion in mice. Mice were housed in an animal room maintained at 34 degrees C for 3 d with water and food freely available. While the hematocrit, extracellular and interstitial fluid volumes increased, the plasma volume decreased. These results suggest that the distribution of body water in mice housed at high environmental temperature exhibit the state of water metabolism disorders (Suitai) described in Kampo medicine. After the administration of XKJ-001 (3 g/kg, once a day) for 5 d, mice were housed in an animal room maintained at 34 degrees C for 3 d. The administration of XKJ-001 was allowed to continue on the day 0, day 1 and day 2. XKJ-001 inhibited the increase in hematocrit and the changes in body water distribution of mice induced by high environmental temperature. An effect of XKJ-001 on water excretion in mice was investigated in comparison with hydrochlorothiazide (HTZ). Distilled water (D.W., 100 ml/kg) or bicarbonate saline (B.S., 100 ml/kg) was intraperitoneally injected immediately after the oral administration of XKJ-001 (1.5 g/kg) or HTZ (15 mg/kg). The water excretion was enhanced after 3 h for XKJ-001 and after 6 h for HTZ after the intraperitoneal injection of D.W. As for the intraperitoneal injection of BS, HTZ enhanced the water excretion, however, XKJ-001 exhibited no effect. These results suggest that XKJ-001 has activities on water maldistribution and facilitates the water excretion.

Animals↗
PubMed1991

[Enhancement of epidermal growth factor receptor (EGF-R) expression on glioma cells by cytokines].

Recombinant tumor necrosis factor alpha (TNF-alpha) significantly enhanced epidermal growth factor receptor (EGF-R) expression in U373-MG glioma cell line as determined by binding of anti-EGF-R monoclonal antibody (MAb) 425. The optimal dose of TNF-alpha was 1000 U/ml of media. When TNF-alpha was combined with recombinant interferon gamma (IFN-gamma), further upregulation of EGF-R was observed. However, IFN-gamma itself did not show any EGF-R enhancement in this cell line. Scatchard analysis of receptor binding revealed that this enhancement of EGF-R expression was due to an increase in the EGF-R density. TNF-alpha did not affect expression of other brain tumor-associated antigens defined by MAb ASHE2, ASHG4 and ASAY1. Cultured fibroblasts showed no upregulation of EGF-R by TNF-alpha, suggesting a differential effect of TNF-alpha on EGF-R expression on glioma cells and normal cells. We investigated whether TNF-alpha treatment of glioma cells increased the tumoricidal effects of radiolabeled MAb 425 which correlate with MAb density on tumor cell surfaces. Growth inhibition of glioma cells in culture by 125I-labeled MAb 425 was significantly enhanced after treatment of the cells with TNF-alpha. In previous clinical trials, 125I-labeled MAb 425 has shown immunotherapeutic effects in glioma patients. The present study provides the basis for considerations of combined immunotherapy of glioma patients with 125I-labeled MAb 425 and cytokines.

Animals↗
PubMed1991

The Xmn I site (-158, C----T) 5' to the G gamma gene: correlation with the Senegalese haplotype and G gamma globin expression.

There are three major African haplotypes associated with the sickle mutation: Benin (#19), Senegalese (#3), and Central African Republic (#20). Previous studies have suggested that the Xmn I site (-158 bp 5' to the G gamma gene) is associated with elevated levels of G gamma and with the Senegalese haplotype, while other investigators questioned this association. In order to clarify the issue, we have determined beta haplotypes, tested for the presence of the Xmn I site, and measured Hb F and G gamma expression levels in 143 American Black patients with sickle cell anemia. Haplotypes were determined using eight polymorphic sites in the beta-like globin gene cluster: Hinc II 5' to epsilon, Hind III in IVS-II G gamma and A gamma, Hinc II within and 3' to psi beta, Ava II in IVS-II of beta, and Hpa I and Bam HI 3' to beta. The G gamma /A gamma ratio was analyzed by high performance liquid chromatography using a C18 column. The Xmn I site was present in all 31 chromosomes with the Sengalese haplotype. Of the remaining 255 chromosomes with other haplotypes, only 2 (0.8%) had the Xmn I site present. There was significant correlation between the presence of the Xmn I site and increased G gamma /A gamma ratio in a dose-dependent manner. The Hb F level was not significantly increased in the presence of the Xmn I site. The data indicate that the Xmn I site maintains a G gamma /A gamma ratio typical of fetal life but does not necessarily cause elevation of Hb F. The latter seems to depend on factors other than the Xmn I site.

Adolescent↗