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Biomedical subjects

M Kobayashi

Publications and source records attributed to M Kobayashi.

At least 343 records · Page 19Linked to original sources
PubMed2001

[The trend of the drug eruptions in the last fifteen years].

The drug eruptions are known to often become more severe by the readministration of causative drugs. It is an important theme to prevent the relapse of the drug eruptions. We have been monitoring drug adverse reactions at our hospital since October, 1980. We divided fifteen years from October, 1980 to September, 1995 into three periods; the first period (Oct., 1980-Sep. 1985), the second period (Oct., 1985-Sep., 1990), and the third period (Oct., 1990-Sep., 1995), and discussed the trend of the drug eruptions appeared among these three periods. The number of the drug eruptions increased. But the proportion to the total drug adverse reactions and to the number of patients slightly decreased. The eruptions in women much increased and in the patients of forties or older generations also increased. But in patients of thirties or younger generations decreased. While nonsteroidal anti-inflammatory drugs (NSAIDs) other than pyrines, antibiotics other than penicillins and cephalosporins and drugs affecting the cardiovascular system and the metabolism tend to increase, pyrines, penicillins, iodic and biliary contrast media tend to decrease. The incubation period before the eruption appeared is less than three days in most antibiotics and anti-inflammatory drugs. But it is more than four days in most drugs for chronic diseases. Other symptoms such as nausea, fever and liver dysfunction were shown in 9.2% of the drug eruptions. In 8.9% of the drug eruptions a relapse of allergic reactions included eruptions were also found. In some cases the drug eruptions exacerbate by re-administration of beta-lactam antibiotics. In the case of administration of drugs, it is necessary to pay attention to dermatitis caused by the drugs. And we recognized the importance of the system for the prevention of the relapse of drug eruptions including injections.

Adolescent↗
PubMed2001

[Effect of combined treatment with vitamin K2 and 1 alpha-(OH)-vitamin D3 on bone loss in ovariectomized rats].

Different types of therapeutic agents for osteoporosis are often simultaneously prescribed for the same patient, but limited experimental findings indicate the significance of combined treatment. In the present study, the inhibitory effect of combined vitamin K2(K2) and 1 alpha-(OH)-vitamin D3(D3) treatment on bone loss was compared to that of K2 or D3 alone in ovariectomized rats. Female rats (20-week-old) were ovariectomized and divided into 4 groups as follows: they were treated for 8 weeks with vehicle, K2 (30 mg/kg), D3 (0.3 microgram/kg) and K2 and D3 (K2 + D3) at the respective doses. K2 was given as a dietary supplement and D3 was orally administered 3 times a week. Bone density of the femurs was measured by peripheral quantitative computed tomography. Ovariectomy resulted in decreased bone density in proximal metaphysis, especially in the trabecular region, and treatment with K2, D3 or K2 + D3 inhibited this decrease. Moreover, in the K2 + D3 group, bone density and mineral content in the trabecular region in proximal metaphysis and cortical bone width in diaphysis were significantly higher than those in the D3 group. Consistent with these observations, bone strength in the femoral midshaft tended to increase only in the K2 + D3 group compared to that in the vehicle group. These findings indicate that combined K2 and D3 treatment is more effective for bone loss than that with K2 or D3 alone.

Animals↗
PubMed2001

Performance of a partially packed charcoal pellet bioreactor for acetic acid fermentation.

The performance of a partially packed charcoal pellet bioreactor was compared to that of a fully packed bioreactor for aerobic acetic acid production. In the fully packed charcoal pellet bioreactor, it was considered that the shortening of an actual retention time of the culture broth limited the bioreactor performance under high dilution rate and high aeration conditions. By reducing the filling ratio of charcoal pellets to 44%, which increased the actual retention time of the culture broth, the maximum productivity increased from 3.9 g/l/h in the fully packed bed bioreactor to 5.7 g/l/h in the partially packed bioreactor without affecting the operational stability.

Journal Article↗
PubMed2001

Enlarged and astaxanthin-accumulating cyst cells of the green alga Haematococcus pluvialis.

The cyst cells of Haematococcus pluvialis were separated into fractions of relatively uniform size by sucrose density gradient centrifugation. The fraction at the bottom of the centrifuge tube with the largest specific gravity from density gradients of mature cysts mainly consisted of enlarged, red cyst cells and had the highest astaxanthin content. To examine the relationship between cell size and astaxanthin content of cysts, formation of the fluorescent dichlorofluorescein (DCF) from 2',7'-dichlorohydrofluorescein diacetate of cyst cells in each fraction from density-gradient centrifugation under oxidative stress caused by methyl viologen (1.0 mM) was studied. The formation of DCF in cyst cells was decreased with larger cell diameter. This decrease was also correlated with increases in astaxanthin content. Therefore, both cell diameter and the fluorescent DCF content of cyst cells would be good parameter to select astaxanthin-hyperproducing strains from native populations of H. pluvialis.

Journal Article↗
PubMed2001

Selective cleavage of the two CS bonds in asymmetrically alkylated dibenzothiophenes by Rhodococcus erythropolis KA2-5-1.

The Rhodococcus erythropolis strain KA2-5-1 was characterized by its ability to cleave carbon-sulfur bonds in the dibenzothiophene (DBT) ring by asymmetrically alkyl substitution, such as C2-DBTs (e.g., dimethyl and ethyl DBTs) and C3-DBTs (e.g., trimethyl and propyl DBTs), which are known to remain in hydrodesulfurization-treated diesel fuels. After treatment by solid-phase extraction (SPE) of solvents from microbial reactions of alkylated DBTs (Cx-DBTs), we used gas chromatography (GC), GC-atomic emission detection, GC-mass spectrometry and 1H nuclear magnetic resonance spectroscopy to identify and quantitatively evaluate the Cx-DBT metabolites. Molar ratios of metabolic isomers of the desulfurization products suggested that resting-cell reactions of KA2-5-1 against these Cx-DBTs occurrs through specific carbon-sulfur-bond-targeted cleavages, yielding alkylated hydroxybiphenyls, and that the manner of the attack on the DBT skeleton is affected not only by the position but also by the number and length of the alkyl substituents.

Journal Article↗
PubMed2001

Structural change and catalytic activity of horseradish peroxidase in oxidative polymerization of phenol.

The effects of solvent and reaction conditions on the catalytic activity of horseradish peroxidase (HRP) were investigated for oxidative polymerization of phenol in water/organic mixtures using hydrogen peroxide as an oxidant. Also, the structural changes of HRP were investigated by CD and absorption spectroscopy in these solvents. The results suggest that the yield of phenol polymer (the conversion of phenol to polymer) is strongly affected by the reaction conditions due to the structural changes of HRP, that is, the changes in higher structure of the apo-protein and dissociation or decomposition of the prosthetic heme. Optimum solvent compositions for phenol polymerization depend on the nature of the organic solvents owing to different effects of the solvents on HRP structure. In addition to initial rapid changes, slower changes of HRP structure occur in water/organic solvents especially at high concentrations of organic solvents. In parallel with these structural changes, catalytic activity of HRP decreases with time in these solvents. At higher reaction temperatures, the yield of the polymer decreases, which is also ascribed to modification of HRP structure. It is known that hydrogen peroxide is an inhibitor of HRP, and the yield of phenol polymer is strongly dependent on the manner of addition of hydrogen peroxide to the reaction solutions. The polymer yield decreases significantly when hydrogen peroxide was added to the reaction solution in a large amount at once. This is probably due to inactivation of HRP by excess hydrogen peroxide. From the CD and absorption spectra, it is suggested that excess hydrogen peroxide causes not only decomposition of the prosthetic heme but also modification of the higher structure of HRP.

Circular Dichroism↗
PubMed2001

Improvement of desulfurization activity in Rhodococcus erythropolis KA2-5-1 by genetic engineering.

Rhodococcus erythropolis KA2-5-1 can desulfurize dibenzothiophene (DBT) into 2-hydroxybiphenyl. A cryptic plasmid, pRC4, which was derived from R. rhodochrous IFO3338, was combined with an Escherichia coli vector to construct an E. coli-Rhodococcus shuttle vector. The complete nucleotide sequence of 2582-bp pRC4 was analyzed. Based on the characteristics of its putative replication genes, pRC4 was assigned to the family of pAL5000-related replicons. The desulfurization gene cluster, dszABC, and the related reductase gene, dszD, cloned from KA2-5-1, were reintroduced into KA2-5-1 and efficiently expressed. The DBT desulfurization ability of the transformant carrying two dszABC clusters and one dszD on the vector was about 4-fold higher than that of the parent strain, and the transformant also showed improved desulfurization activity for light gas oil (LGO). Sulfur components in LGO before and after the reaction were analyzed with gas chromatography-atomic emission detection.

Amino Acid Sequence↗
PubMed2001

Kinetic analysis of microbial desulfurization of model and light gas oils containing multiple alkyl dibenzothiophenes.

The reaction mechanism of biodesulfurization was investigated using whole cells of Rhodococcus erythropolis KA2-5-1, which have the ability to convert dibenzothiophene (DBT) into 2-hydroxybiphenyl. The desulfurization patterns of alkyl DBTs were represented by the Michaeis-Menten equation. The values of rate constants, the limiting maximal velocity (Vmax) and Michaelis constant (Km), for desulfurization of alkyl DBTs were calculated. The relative desulfurization activities of various alkyl DBTs were reduced in proportion to the total carbon numbers of alkyl substituent groups. Alkyl DBTs that had a total of six carbons of alkyl substituent groups were not desulfurized. The type or position of alkyl substituent groups had little effect on desulfurization activity. The desulfurization activity of each alkyl DBT, when mixed together, was reduced. This phenomenon was caused by apparent competitive inhibition of substrates. Using the apparent competitive inhibition model, the desulfurization pattern of a multiple components system containing alkyl DBTs was elucidated. This model was also applicable for biodesulfurization of light gas oil.

Biodegradation, Environmental↗
PubMed2001

[Silent myocardial ischemia and exercise-induced arrhythmia detected by the exercise test in the total health promotion plan (THP)].

We investigated the prevalence and characteristics of ischemic heart disease especially silent myocardial ischemia (SMI) and arrhythmia in need of careful observation in the exercise stress tests in the Total Health Promotion Plan (THP), which was conducted between 1994-96 for the purpose of measuring cardiopulmonary function. All workers (n = 4,918, 4,426 males) aged 18-60 yr old in an occupational field were studied. Exercise tests with an ergometer were performed by the LOPS protocol, in which the maximal workload was set up as a presumed 70-80% maximal oxygen intake, or STEP (original multistage protocol). ECG changes were evaluated with a CC5 lead. Two hundred and fifteen people refused the study because of a common cold, lumbago and so on. Of 4,703 subjects, 17 with abnormal rest ECG and 19 with probable anginal pain were excluded from the exercise tests. Of 4,667 who underwent the exercise test, 37 (0.79%) had ischemic ECG change, and 155 (3.32%) had striking arrhythmia. These 228 subjects then did a treadmill exercise test with Bruce protocol. Twenty-two (0.47% of 4,703) showed positive ECG change, 9 (0.19%) of 22 had abnormal findings on a 201Tl scan. 8 (0.17%) were diagnosed as SMI (Cohn I), in which the prevalence of hypertension, hyperlipidemia, diabetes mellitus, smoker and positive familial history of ischemic heart disease was greater than that of all subjects. In a 15-30 month follow up, none has developed cardiac accidents. Exercise-induced arrhythmia was detected in 11 (0.23%) subjects. Four were non-sustained ventricular tachycardia without any organic disease, 4 were ventricular arrhythmia based on cardiomyopathy detected by echocardiography, 2 were atrial fibrillation and another was WPW syndrome. It is therefore likely that the ergometer exercise test in THP was effective in preventing sudden death caused by ischemic heart disease or striking arrhythmia.

Adolescent↗
PubMed2001

Short-term hyperthyroidism followed by transient pituitary hypothyroidism in a very low birth weight infant born to a mother with uncontrolled Graves' disease.

Transient hypothyroxinemia in infants born to mothers with poorly controlled Graves' disease was first reported in 1988. We report that short-term hyperthyroidism followed by hypothyroidism with low basal thyroid-stimulating hormone (TSH) levels developed in a very low birth weight infant born at 27 weeks of gestation to a noncompliant mother with thyrotoxicosis attributable to Graves' disease. We performed serial thyrotropin-releasing hormone (TRH) tests in this infant and demonstrated that TSH unresponsiveness to TRH disappeared at 6.5 months of age. The maternal thyroid function was free triiodothyronine (FT(3)), 21.1 pg/mL; free thyroxine (FT(4)), 8.1 ng/dL; TSH, <0.03 microU/mL; thyroid-stimulating hormone receptor antibody, 52% (normal: <15%); thyroid-stimulating antibody, 294% (normal: <180%); and thyroid-stimulation blocking antibody, 9% (normal: <25%) on the day of delivery. A nonstress test revealed fetal tachycardia >200 beats per minute, and a male infant weighing 1152 g was born by emergency cesarean section. Thyroid-stimulating hormone receptor antibody was 16% and thyroid-stimulating antibody was 370% in the cord blood. We administered 10 mg/kg per day of oral propylthiouracil from day 1. Tachycardia along with elevated FT(4) and FT(3) levels in the infant decreased from 200/minute to 170/minute, 4.7 ng/dL to 2.9 ng/dL, 7.0 pg/mL to 4.8 pg/mL, respectively, in the first 33 hours. At 5 days, FT(4) and FT(3) were 1.1 ng/dL and 2.9 pg/mL, respectively, and we stopped propylthiouracil administration. Although FT(4) decreased to 0.4 ng/dL, TSH was quite low and did not respond to intravenous TRH by 14 days of age. We began daily levothyroxine 5-micro/kg supplementation. The responsiveness of TSH to TRH did not become significant until 4 months old and normalized at 6.5 months old. At this time, levothyroxine was stopped. We conclude that placental transfer of thyroid hormones may cause hyperthyroidism in the fetal and early neonatal periods and lead to transient pituitary hypothyroidism in an infant born to a mother with uncontrolled Graves' disease.

Adult↗
PubMed2001

Concentrations of trace elements in sweat during sauna bathing.

Trace elements in sweat during sauna bathing were assessed. Sweat collected by the whole body method was compared with that collected by the arm bag method. The sweat samples were collected from ten healthy male adults aged 22-26 years, by heat exposure in dry sauna bathing (60 degrees C, 30 minutes). Concentrations of major (Na, Cl, K, Ca, P and Mg) and trace (Zn, Cu, Fe, Ni, Cr and Mn) elements in sweat tended to be lower in the arm bag method than in the whole body method. It was found that Ca, Mg, Fe and Mn concentrations in the arm bag method were significantly lower than those in the whole body method. The amount of trace elements in sweat measured by the arm bag method was less than that by the whole body method; significant differences were observed in Fe and Mn amounts. These observations suggest that excretion of trace elements by sweating induces trace element decrease. Therefore, athletes and workers who work in a hot environment and sweat much habitually should ingest adequate amounts of trace elements.

Adult↗
PubMed2001

Arrangement of D-periodic collagen fibrils and association of proteoglycans with fibrils in the synovium of the mouse temporomandibular joint.

The present study was performed to examine changes in the arrangement of D-periodic collagen fibrils in the synovium of the growing temporomandibular joint in mice. At 1 week of age, the mandibular condyle was undeveloped, and only a few collagen fibrils were recognizable in the subintimal layer of the synovium. At 8 weeks, the mandibular condyle was structurally developed with an increase of collagen fibrils in the synovium; a fully mature condyle was observed at 6 months of age. The close association of proteoglycans with collagen fibrils in the synovium of the growing joint was examined by both conventional and energy-filtering transmission electron microscopy of cupromeronic blue-stained specimens. Proteoglycans were associated with D-periodic collagen fibrils in the short filamentous form in random fashion at 1 week of age, but in a regular pattern with D-periodicity at 6 months. These associations in the synovium could be correlated with the mechanical character of the temporomandibular joint.

Age Factors↗
PubMed2001

Participation of periodontal ligament cells with regeneration of alveolar bone.

BACKGROUND: It is important to clarify the participation of periodontal ligament (PDL) cells in the regeneration of alveolar bone to establish a reliable approach for obtaining periodontal regeneration. The aim of this study was to determine whether PDL cells play an important role in alveolar bone repair during the course of periodontal regeneration. METHODS: In an in vitro study, the expression of the osteoblast phenotype, such as alkaline phosphatase activity and parathyroid hormone-dependent 3',5'-cyclic adenosine monophosphate accumulation, was investigated in dog PDL cells (DPLC) and dog bone cells isolated from mandibles (DBC). In a related study, the roots of mandibular third premolars extracted from aged dogs were divided into a PDL(+) group, in which the PDL was preserved, and a PDL(-) group, in which the PDL was removed. These roots were respectively transplanted into surgically created bone cavities with buccal and interproximal bone defects in an edentulous area, prepared in advance by extraction of mandibular fourth premolars. These bone defects with the transplanted roots were completely covered with submerged physical barrier membranes. New bone formation and new connective tissue attachment, which require new cementum and insertion of functionally oriented new collagen fibers of periodontal ligament, were histomorphometrically assessed, and were compared between the PDL(+) and PDL(-) groups 6 weeks after transplantation. RESULTS: Both cultured DPLC and DBC exhibited the osteoblast phenotype. New connective tissue attachment was observed only in the PDL(+) group. However, alveolar bone was almost completely regenerated to the original bone height in both the PDL(+) and PDL(-) groups, and the amount of newly formed bone was not significantly different between the 2 groups. CONCLUSIONS: DPLC retain the capability to differentiate into an osteoblast lineage and may act in the regeneration of periodontal ligament with new cementum formation, whereas these cells may have a limited influence on alveolar bone formation during the course of periodontal regeneration.

Alkaline Phosphatase↗
PubMed2001

Clinical periodontal findings and microflora profiles in children with chronic neutropenia under supervised oral hygiene.

BACKGROUND: This is the first known case report that used a polymerase chain reaction (PCR)-based method to help identify the oral microflora in patients with chronic neutropenia. In this study, we report clinical periodontal findings and microflora profiles of 2 children, 1 with severe congenital neutropenia (SCN, Kostmann type) and 1 with cyclic neutropenia (CN). METHODS: The SCN patient had severe gingivitis, whereas the patient with CN had mild gingivitis in the gingival margins. Monthly oral cleaning instruction and review were performed without subsequent periodontal therapy. Oral hygiene conditions remained satisfactory and visible plaque was scarce, despite the persistence of mild gingivitis. Under supervised oral hygiene, we examined the presence of periodontal pathogens from patient plaque samples. RESULTS: By a PCR-based method, Prevotella nigrescens, Bacteroides forsythus, Campylobacter rectus, and Capnocytophaga gingivalis were detected in the SCN patient and P. intermedia, C. rectus, C. gingivalis, and C. sputigena in the CN patient, suggesting the existence of periodontal pathogens. Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and C. ochracea were not found in either patient. CONCLUSIONS: Use of 1% povidone iodine solution and local antibiotic application under supervised oral hygiene were helpful to improve gingival conditions in patients with chronic neutropenia.

Aggregatibacter actinomycetemcomitans↗
PubMed2001

Polyvinyl alcohol as a useful indicator on iodometry: volumetric and spectrophotometric studies on iodine-PVA and iodine-starch complexes.

Iodometry is one of the easiest, most rapid and accurate methods for the determination of a relatively small amount of oxidizing agent, such as residual chlorine. Starch has long been used as a useful color indicator in iodometry. However, we found that PVA (polyvinyl alcohol with partially saponificated; e.g., saponification degree of 88%) is a more useful color indicator than starch. For example, at 20 degrees C, the PVA indicator gave similar profiles of iodine concentration vs. titration efficiencies (percent recoveries) to those of starch at 0 degrees C. At 0 degrees C, the PVA indicator detected 1.1 mg I2/L (11 microg I2: with 10 mL sample volume) with a high percentage of recovery (=95%). Furthermore, at 20 degrees C an iodine concentration of 0.36 mg/L (which corresponds to a residual chlorine concentration of 0.1 mg Cl2/L) could be detected using PVA color indicator assuming an appropriate correction.

Chlorine↗
PubMed2001

Serum levels of KL-6 reflect disease activity of interstitial pneumonia associated with ANCA-related vasculitis.

OBJECTIVE: KL-6 is reported to be excreted from the lung alveolar and bronchial epithelial cells and may be a good marker for monitoring disease activity of interstitial pneumonia. This study was designed to ascertain the clinical significance of serum KL-6 levels in interstitial pneumonia associated with anti-neutrophil cytoplasmic antibody (ANCA)-related vasculitis. METHODS: Serum KL-6 levels were determined by an enzyme-linked immunosorbent assay. PATIENTS: We examined 20 healthy subjects, 13 patients with perinuclear (myeloperoxidase, MPO) ANCA-related vasculitis and 12 dermatomyositis (DM)/polymyositis (PM) patients as disease controls in this study. Six out of 13 patients with ANCA-related vasculitis had interstitial pneumonia. RESULTS: Serum levels of KL-6 in ANCA-positive patients with interstitial pneumonia were significantly elevated, while they remained as low as those of healthy subjects in ANCA-positive patients without interstitial pneumonia. Similarly, KL-6 levels in sera were higher in 12 dermatomyositis/polymyositis patients with interstitial pneumonia, while they remained low in DM/PM patients without interstitial pneumonia. Moreover, the elevated serum KL-6 level was reduced during the convalescence induced by glucocorticoid therapy and reflected the disease activity of interstitial pneumonia associated with ANCA-related vasculitis. CONCLUSION: These data suggest that the measurement of serum KL-6 levels may be a good monitoring system for the diagnosis and follow-up of interstitial pneumonia of patients with ANCA-related vasculitis.

Aged↗
PubMed2001

A patient with chronic hepatitis C who obtained sustained response by retreatment of interferon after decrease of viral load and mutation in interferon sensitivity determining region.

A 44-year-old man with chronic hepatitis C received three courses of interferon (IFN) therapy. HCV genotype was 1b, viral load was 1,200 kcopies/ml and interferon sensitivity determining region (ISDR) was the intermediate type before the 1st IFN therapy. The 1st and 2nd IFN therapies resulted in failure to yield a sustained response. Seven years after from the 1st therapy, viral load had decreased to 15 kcopies/ml and ISDR had changed to mutant type. The 3rd IFN therapy yielded sustained response. Thus, we should consider retreatment with IFN when a decrease of the viral load and change of ISDR to mutant type are observed.

Adult↗