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Biomedical subjects

H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 217 records · Page 12Linked to original sources
PubMed2000

Immunological characterization of C3H mice congenic for Fas(lprcg), C3h/HeJ-Fas(lprcg)/Fas(lprcg).

Fas(lpr) (lpr) and Fas(lprcg) (lpr(cg)) are allelic mutations of the Fas gene that is involved in apoptosis or programmed cell death. Lpr greatly reduces the expression of functional Fas and lpr(cg) expresses the death domain-disabled, non-functional Fas on the cell surface. C3H/HeJ mice congenic for lpr(cg) (C3H-lpr(cg)) were established and compared with C3H/HeJ-lpr/lpr (C3H-lpr) mice for their immunological and pathological features. Lymphadenopathy, splenomegaly, development of CD4- CD8- B220+ or double-negative (DN) T cells, renal pathology, and lymphoid cell infiltration in the lung and liver were not significantly different between C3H-lpr(cg) and C3H-lpr mice. Noticeably, however, the production of serum immunoglobulin, autoantibodies against double-strand DNA and serum immune complexes were significantly lower in C3H-lpr(cg) than in C3H-lpr mice. The results indicate that the death signal through the death domain of Fas is responsible for lymphoproliferation due to the accumulation of DN T cells and suggest that the region of Fas outside the death domain may be involved in autoantibody production. The newly-developed congenic C3H-lpr(cg) mice will provide a powerful tool for research into the function of Fas apart from apoptosis.

Alleles↗
PubMed2000

High molecular weight transglutaminase inhibitor produced by a microorganism (Streptomyces lavendulae Y-200).

Transglutaminases catalyze the cross-linking and amine incorporation of proteins, and are implicated in various biological phenomena such as blood clotting, wound healing, apoptosis, and cell differentiation. Streptomyces lavendulae Y-200, isolated from soil, produced a substance that inhibited transglutaminases. The inhibitory substance was purified from the cultured medium by procedures of acid precipitation, deoxyribonuclease treatment, and gel filtration chromatography. The partially purified sample was dark brown. The inhibitory activity was stable under acidic, alkaline, and high temperature conditions, and resistant to the treatment with proteinases such as trypsin and Pronase. The molecular weight of the inhibitory substance was estimated to be between 10(4) and 10(5) from its permeability through ultrafilter membranes. The acid hydrolysate of the inhibitory substance contained amino acids and sugars. The inhibitory substance inhibited both calcium-dependent and calcium-independent transglutaminases in a competitive manner with a glutamine substrate. The extent of inhibition caused by the calcium-dependent transglutaminase increased with increasing calcium concentration. The results obtained here may help identify a novel regulatory substance of transglutaminase in biological systems.

Animals↗
PubMed2000

Synthesis of novel heterobranched beta-cyclodextrins from 4(2)-O-beta-D-galactosyl-maltose and beta-cyclodextrin by the reverse action of pullulanase, and isolation and characterization of the products.

From the mixture of 4(2)-O-beta-D-galactosyl-maltose (Gal-G2) and beta-cyclodextrin (betaCD), novel heterobranched betaCDs, (Gal-G2)-betaCD and (Gal-G2)2-betaCDs, were synthesized by the reverse action of debranching enzyme. The optimum conditions for the production of (Gal-G2)2-betaCDs were examined. A mixture of (Gal-G2)2-betaCDs was produced in about 4% yield when Aerobacter aerogenes pullulanase (64 units per 1 g of Gal-G2) was incubated with 1.6 M Gal-G2 and 0.16 M betaCD at 50 degrees C for 4 days. The reaction products, (Gal-G2)2-betaCDs, were separated into three peaks by HPLC analysis on a Hypercarb S column. Their structures were analyzed by fast atom bombardment mass spectroscopy and NMR spectroscopies, and confirmed by comparison of their hydrolyzates by beta-galactosidase with the authentic (G2)2 -betaCDs. The structures of (Gal-G2)-betaCD and three components of (Gal-G2)2-betaCDs were identified as 6-O-(GalG2)-betaCD, 6(1),6(2)-, 6(1),6(3)- and 6(1),6(4)-di-O-(Gal-G2)2-betaCD, respectively.

Carbohydrate Sequence↗
PubMed2000

Molecular characterization of a novel yeast cell-wall acid phosphatase cloned from Kluyveromyces marxianus.

A novel Kluyveromyces marxianus gene that encodes an acid phosphatase, Pho610, was cloned in Saccharomyces cerevisiae. The deduced amino acid sequence was distinct from S. cerevisiae phosphatases but similar to some fungal enzymes. A peculiar feature of the sequence is that it has hydrophobic stretches both at the N- and C-termini, which is a characteristic of the precursors of glycosylphosphatidylinositol(GPI)-anchored proteins. When the gene was expressed in S. cerevisiae, the active enzyme was recovered in the periplasmic fraction by glucanase digestion. The Pho610 polypeptide was highly glycosylated and a significant portion was covalently linked to the cell-wall glucan. The enzyme was secreted when the C-terminal region was truncated to remove the GPI signal. Therefore, Pho610 is a novel cell-wall protein having an enzyme activity.

Acid Phosphatase↗
PubMed2000

Effects of branched cyclodextrins on the solubility and stability of terpenes.

In order to investigate the application potential of branched CDs, the solubilizing ability and the stabilizing ability of G2-betaCD and GUG-betaCD were investigated by using twelve terpenes (d-limonene, myrcene, terpinolene, geraniol, l-menthol, nerol, alpha-terpineol, citral, d-citronellal, l-perillaldehyde, (R)-l-carvone, and menthone) as guest compounds. G2-betaCD and GUG-betaCD showed more solubilizing ability for these twelve terpenes than betaCD, and the ability of GUG-betaCD was almost the same as that of G2-betaCD. The stabilizing ability of terpene-GUG-betaCD complexes was different from that of G2-betaCD. GUG-betaCD was superior to G2-betaCD, especially in the solid state. This result may have been caused by the difference in structure of side chain, namely the hydroxymethyl group in G2-betaCD and the carboxyl group in GUG-betaCD.

Cyclodextrins↗
PubMed2000

Pseudomalabsorption of levothyroxine: a case report.

A 51-year-old woman who had been treated with levothyroxine sodium because of hypothyroidism after total thyroidectomy for thyroidal cancer was admitted to our hospital for persistent hypothyroidism despite large dose administration of levothyroxine (600 microg/day). The patient complained of severe general fatigue and body weight gain. Free thyroxine, free triiodothyronine and thyrotropin levels were 0.97 ng/dl, 1.55 pg/ml and 24.51 microU/ml, respectively, under oral administration of levothyroxine. Levothyroxine loading test performed by liquid form, pulverized tablets via nasogastric tube and intravenous administration revealed no evidence of malabsorption or metabolic disorder of levothyroxine, although oral intake of tablets was ineffective due to her factitiousness. We report here a possible case of "pseudomalabsorption of levothyroxine" to emphasize the clinical recognition of this disorder in patients with resistant hypothyroidism.

Dose-Response Relationship, Drug↗
PubMed2000

[A case of hypopituitarism and primary hypothyroidism associated with antiphospholipid syndrome].

Recent reports have indicated that antiphospholipid antibodies (aPL) are related to other clinical manifestations such as cardiac valve lesions and hemolytic anemia besides the major clinical features of antiphospholipid syndrome (APS), including thrombocytopenia, and recurrent fetal demise. We recently encountered a case of multiple hormonal deficiencies in the pituitary gland and hypothyroidism associated with an APS. Hypopituitarism of the patient had occurred after her delivery and a magnetic resonance imaging (MRI) examination disclosed "empty sella" of the hypophysis, so she was thought to have Sheehan's syndrome. There has been a few reports describing the relationship between aPL and endocrine disorders. aPL-related onset of these diseases may be more frequent than is generally appreciated.

Adult↗
PubMed2000

[Survival conditions of microorganisms under extremely severe environment].

The survival conditions of microorganisms under extremely severe environment are of interest in various areas of biology, sterilization, and space engineering, especially where resistance to microorganisms is concerned. Despite the interest, the resistance to microorganisms under extremely severe environment such as space environment or other planetary environment is not known well. In order to investigate survival conditions of microorganisms under extremely severe environment, surviving fractions for spores and vegetative cells of Bacillus subtilis were surveyed in various chemical species of atmosphere at various pressures and various temperatures, and the dependence on time for surviving fractions was examined. The results show: (i) Surviving fractions depend on chemical species of atmosphere. (ii) At high pressure and high temperature, surviving fractions are low and the resistance of spores is stronger than that of vegetative cells. (iii) Surviving fractions decrease as first-order reaction along with time elapsed.

Argon↗
PubMed2000

Evolution of peripheral lung adenocarcinomas: CT findings correlated with histology and tumor doubling time.

OBJECTIVE: This study was performed to evaluate the evolution of peripheral lung adenocarcinomas using CT findings and histologic classification related to tumor doubling time. MATERIALS AND METHODS: The subjects were 34 patients, each with an adenocarcinoma smaller than 3 cm. All patients underwent chest radiography and 10 of them had previously undergone CT more than 6 months before surgery. Tumor doubling time was estimated by examining sequential radiographs using the method originally described by Schwartz. Tumor growth was also observed by studying the changes on CT in the 10 patients who had previously undergone CT. The histologic classification (types A-F) was evaluated according to the criteria of Noguchi et al. RESULTS: Five (83%) of the six adenocarcinomas with tumor types A or B showed localized ground-glass opacity on high-resolution CT. All six tumors had a tumor doubling time of more than 1 year. Fifteen (71%) of the 21 tumors with type C showed partial ground-glass opacity mixed with localized solid attenuation on high-resolution CT. Ten (48%) of these 21 type C tumors had a tumor doubling time of more than 1 year. In types B and C, the solid component or the development of pleural indentation and vascular convergence increased during observation before surgery. All seven tumors with types D, E, and F showed mostly solid attenuation, and the tumor doubling time was less than 1 year in six (87%) of the seven tumors. CONCLUSION: Two main types of peripheral lung adenocarcinoma exist. The first type appears on CT as a localized ground-glass opacity with slow growth, and the other appears as a solid attenuation with rapid growth.

Adenocarcinoma↗
PubMed2000

Detection of anti-neutrophil cytoplasmic antibodies in MRL/Mp-lpr/lpr mice and analysis of their target antigens.

Anti-neutrophil cytoplasmic antibodies (ANCA) have been widely studied and recognized to be clinically very important for some human diseases including systemic rheumatic diseases. We analyzed ANCA response and their target antigens in MRL/Mp-lpr/lpr (MRL-lpr) mice, an animal model of systemic rheumatic disease. P-ANCA was detected in 57% of the mice. Antibodies to the known P-ANCA target antigens at the same age were examined. Among these, antibodies to high mobility group (HMG) proteins HMG1 and HMG2 were detected in 57% of the mice, 75% of which were also positive for P-ANCA. These anti-HMG1/HMG2 activities were absorbed by preincubation with a mixture of HMG1 and HMG2. In contrast, antibodies to myeloperoxidase and cathepsin G were detected in 14% and 7%, respectively, but these activities were not inhibited by preincubation with corresponding antigens. In addition, the titers of P-ANCA and anti-HMG1/HMG2 antibodies in MRL-lpr mice were significantly correlated with each other. Thus, HMG1 and HMG2 were considered to be significant target antigens of P-ANCA in MRL-lpr mice.

Animals↗
PubMed2000

Sequence analysis of human endogenous retrovirus clone 4-1 in systemic lupus erythematosus.

Human endogenous retroviruses (HERV) have emerged as a possible cause of systemic lupus erythematosus (SLE). We previously detected serum antibodies to the gag region of HERV clone 4-1 in patients with SLE, but not in normal volunteers. In the present study, we detected clone 4-1 messenger RNA (mRNA) in peripheral blood mononuclear cells (PBMC) from SLE patients and performed sequence analysis of the cDNA or genomic DNA from clone 4-1 in these patients. Clone 4-1 mRNA was detected in all of the SLE patients tested, although it was not found in normal controls. Sequence analysis of clone 4-1 in these SLE patients revealed inactivation of the stop codons in part of the gag region. In addition, a computer search of current sequence libraries revealed that the clone 4-1 gag genomic DNA from SLE patients was more highly homologous with the clone 4-1 sequence in chromosome 11 from normal individuals when compared with the sequence of clone 4-1 integrated in the other chromosomes. It is possible that transcription of clone 4-1 from chromosome 11 occurs in SLE, and that the stop codon inactivation contributes to the translation of clone 4-1 gag proteins in patients with this disease.

Adult↗
PubMed2000

[Risk factors of anastomotic leak following operations for gastric cancer in the elderly].

The risk factors of anastomotic leak in the elderly following operations for gastric cancer were evaluated by multiple logistic model analysis. Data were taken from 705 operations over a 14-year period. The mean age of patients was 75.8 +/- 7.6 years. The significant risk factors for anastomotic leak were amounts of intra-operative bleeding and male gender. No other factors were significant, including age, preoperative associated diseases, preoperative nutritional states and postoperative complications, some of which were, however, significant factors by univariate analyses. We conclude that we should make every endeavor to lower the amount of intra-operative bleeding in order to prevent postoperative anastomotic leaks in the elderly, especially in male patients.

Adult↗
PubMed2000

Effect of administration of fermented milk containing whey protein concentrate to rats and healthy men on serum lipids and blood pressure.

The effect of fermented milk supplemented with whey protein concentrate on the serum lipid level of rats was investigated. The serum total cholesterol level for the group fed fermented milk with both Lactobacillus casei TMC0409 and Streptococcus thermophilus TMC 1543 was significantly lower than that of the control group (P<0.05) in rats. Furthermore, the effect of the longterm intake of this fermented milk on the serum lipid level of twenty healthy adult men was investigated. During the 8-wk study, the volunteers consumed 200 ml of fermented milk or placebo in the morning and evening. Blood samples were drawn for analysis three times, just before taking the experimental diet, and after 4 wk and 8 wk of consumption. After 8 wk, the high density lipoprotein cholesterol level for the fermented milk group showed a significant rise after 4 wk (P<0.05), whereas that of the placebo group showed no change even after 4 wk (P>0.05). The triglyceride level for the fermented milk group lowered significantly after 4 wk (<0.05), whereas that of the placebo group showed no change even after 4 wk (P>0.05). The atherogenic index [(total cholesterol - high density lipoprotein cholesterol)/high-density lipoprotein cholesterol] for the fermented milk group decreased significantly from 4.24 to 3.52 (P<0.05). The systolic blood pressure lowered significantly by the intake of fermented milk (P<0.05) On the other hand, such effect was not observed in the placebo group (P>0.05). These results indicate potential of the development of fermented milk with multiple therapeutic effects.

Adult↗
PubMed2000

Use of spiral computerized tomography angiography in patients with subarachnoid hemorrhage in whom subtraction angiography did not reveal cerebral aneurysms.

OBJECT: Patients with subarachnoid hemorrhage (SAH) in whom angiography does not demonstrate diagnostic findings sometimes suffer recurrent disease and actually harbor undetected cerebral aneurysms. The management strategy for such cases remains controversial, but technological advances in spiral computerized tomography (CT) angiography are changing the picture. The purpose of this prospective study was to examine how spiral CT angiography can contribute to the detection of cerebral aneurysms that cannot be visualized on angiography. METHODS: In 134 consecutive patients with SAH, a prospective search for the source of bleeding was performed using digital subtraction (DS) and spiral CT angiography. In 21 patients in whom initial DS angiography yielded no diagnostic findings, spiral CT angiography was performed within 3 days. Patients in whom CT angiography provided no diagnostic results underwent second and third DS angiography sessions after approximately 2 weeks and 6 months, respectively. Six patients with perimesencephalic SAH were included in the 21 cases. Six of the other 15 patients had small cerebral aneurysms detectable by spiral CT angiography, five involving the anterior communicating artery and one the middle cerebral artery. Two patients in whom initial angiograms did not demonstrate diagnostic findings proved to have a ruptured dissecting aneurysm of the vertebral artery; in one case this was revealed at autopsy and in the other during the second DS angiography session. A third DS angiography session revealed no diagnostic results in 13 patients. CONCLUSIONS: Spiral CT angiography was useful in the detection of cerebral aneurysms in patients with SAH in whom angiography revealed no diagnostic findings. Anterior communicating artery aneurysms are generally well hidden in these types of SAH cases. A repeated angiography session was warranted in patients with nonperimesencephalic SAH and in whom initial angiography revealed no diagnostic findings, although a third session was thought to be superfluous.

Adult↗
PubMed2000

[Interchangeability of resin composites and bonding agents based on bis-GMA or UDMA].

Recently, dentin bonding systems have been released separately from the resin composites, because the adhesive systems have been quickly improved. Since the merit of each material should be effectively utilized for each clinical case, the bonding systems and resin composites produced by different manufacturers may be combined according to the clinical purpose. The current restorative resins are basically categorized into two groups according to the main resin monomer, bis-GMA or UDMA resins. The purpose of this study was to evaluate the interchangeability between the bonding systems and resin composites, which were made by different manufacturers. Two bonding systems and five resin composites based on bis-GMA or UDMA were used in this study. The evaluation was performed by the tensile bond strength, fracture modes, and SEM observation, using the dentin surface of freshly-extracted bovine teeth. The highest bond strength (19.2 MPa) was shown by the combination of LBII sigma and AP-X. The bond strengths of nine other combinations were not statistically different (p > 0.05). There were many cohesive failures in dentin or resin composite, using all combinations. From the results, it was concluded that the interchangeability of the resin composites and bonding systems should be clinically acceptable.

Animals↗