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Biomedical subjects

A Kobayashi

Publications and source records attributed to A Kobayashi.

At least 73 records · Page 4Linked to original sources
PubMed2001

Trisomy 21 as the sole acquired karyotypic abnormality in an adult patient with CD7-positive acute myeloid leukemia.

We report a unique case of acute myeloid leukemia (AML) in which trisomy 21 was the sole acquired karyotypic abnormality. The blasts were positive for myeloperoxidase, and phenotypic analysis of peripheral blood cells by flow cytometry demonstrated positivity for CD7, CD13, CD33, and CD34. chromosomal analysis of peripheral blood and bone marrow cells showed trisomy 21; however, that of the buccal mucosal membrane revealed a normal karyotype. A diagnosis of CD7+AML (M2) with trisomy 21 was diagnosed and the patient achieved complete remission following treatment with Japan Adult Leukemia Study Group-AML97 protocol. This is the first reported case of CD7+AML with trisomy 21 as the sole cytogenetic abnormality.

Adult↗
PubMed2001

Analysis of glycosidically bound aroma precursors in tea leaves. 2. Changes in glycoside contents and glycosidase activities in tea leaves during the black tea manufacturing process.

Glycosides are known to be precursors of the alcoholic aroma compounds of black tea. They are hydrolyzed by endogenous glycosidases during the manufacturing process. Changes in the amounts of these glycosides during the manufacturing process were investigated by using a capillary gas chromatographic--mass spectrometric analysis after trifluoroacetyl derivatization of the tea glycosidic fractions. Primeverosides were 3-fold more abundant than glucosides in fresh leaves, but they decreased greatly during the manufacturing process, especially during the stage of rolling. After the final stage of fermentation, primeverosides had almost disappeared, whereas glucosides were substantially unchanged. These results show that hydrolysis of the glycosides mainly occurred during the stage of rolling and confirm that primeverosides are the main black tea aroma precursors. This was also supported by the changes in the glycosidase activities in tea leaves. The glycosidase activities remained at a high level during withering but decreased drastically after rolling.

Fermentation↗
PubMed2001

Analysis of glycosidically bound aroma precursors in tea leaves. 3. Change in the glycoside content of tea leaves during the oolong tea manufacturing process.

A direct qualitative and quantitative determination of the glycosides of tea aroma compounds at the four stages of the oolong tea manufacturing process (plucking, solar withering, indoor withering, and oolong tea product) was carried out by a capillary gas chromatographic-mass spectrometric analysis after trifluoroacetyl derivatization of the glycosidic fractions. Sixteen glucosides and primeverosides were identified and quantified in cv. Chin-shin-oolong and cv. Chinhsuan-oolong. A comparison of the glycosides in dried fresh leaves between the two cultivars showed significant differences. During the manufacturing process, the amounts of most of these glycosides increased from the solar-withering stage, reaching the highest level at the final stage of oolong tea production. It was noted that no glycoside decreased in its content during the manufacturing process, this being quite different from the manufacture of black tea. In addition, the contents of these alcoholic aroma compounds in the free aroma concentrate from each cultivar remained almost unchanged or slightly decreased, and they constituted only about 12 and 17% in amount of the whole oolong tea aroma compounds. However, jasmine lactone and indole were markedly higher in the final oolong tea products.

Chromatography, Gas↗
PubMed2001

Isolation of some glycosides as aroma precursors in young leaves of Japanese pepper (Xanthoxylum piperitum DC.).

To clarify the formation mechanism for the major alcoholic aroma compounds in young leaves of Japanese pepper, the glycosides were isolated as aroma precursors. The presence of glycosides of the main alcoholic aroma constituents was indirectly determined by enzymatic hydrolysis and trifluoroacetylation (TFA) of the glycoside-containing fraction. After Amberlite XAD-2 column chromatography, ODS flash chromatography, and high-performance liquid chromatography (HPLC), two new compounds, namely, (3S,6S)-cis-linalool-3,7-oxide beta-D-glucopyranoside and 2-methylpropanyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside, were isolated. In addition, (3S,6R)-cis-linalool-3,6-oxide beta-D-glucopyranoside, which absolute configuration was the first determined, and six known glycosides, citronellyl beta-D-glucopyranoside, linalyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside, (Z)-3-hexenyl beta-D-glucopyranoside, benzyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside, dendranthemoside A, and 3,6-dihydroxy-5,6-dihydro-beta-ionol 9-beta-D-glucopyranoside, were isolated. All of these glycosides were isolated for the first time from the leaves of Japanese pepper. Their structures were established on the basis of spectral data and chemical evidence. The ratios of stereoisomers of the aglycon moieties of citronellyl beta-D-glucopyranoside and linalyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside were investigated by a chiral GC analysis and compared with those of free citronellol and linalool in the aroma concentrate.

Capsicum↗
PubMed2001

Different origin of hypertriglyceridemia induced by a high-fat and a high-sucrose diet in ventromedial hypothalamic-lesioned obese and normal rats.

OBJECTIVE: To clarify the mechanism by which plasma triacylglycerol is affected by a high fat or a sucrose diet. DESIGN: Two sets of six groups each having six rats were prepared-(1) ventromedial hypothalamic (VMH)-lesioned rats fed a standard diet; (2) sham VMH-lesioned rats fed a standard diet; (3) VMH-lesioned rats fed a high-fat diet; (4) sham VMH-lesioned rats fed a high-fat diet; (5) VMH-lesioned rats fed a high-sucrose diet; and (6) sham VMH-lesioned rats fed a high-sucrose diet. After VMH lesions and sham operations, the rats were provided standard, high-fat and high sucrose diets for 2 weeks. Two weeks later, blood samples were collected after overnight fast to determine plasma triacylglycerol (TAG), hepatic triacylglycerol secretion rate (TGSR), fractional catabolic rate (FCR) of triacylglycerol and postheparin plasma lipoprotein lipase (LPL), plasma glucose, insulin and leptin. RESULTS: Values of TAG, TGSR, FCR and LPL in VMH-lesioned obese rats were all greater than those in sham-operated rats, regardless of the diet fed. In sham-operated rats, high-fat diet fed rats showed higher TAG with similar TGSR, higher LPL and lower FCR than those of standard diet fed rats. High-sucrose diet fed rats showed significantly higher TAG with higher TGSR, higher LPL and lower FCR than those of standard diet fed rats. Moreover, high-sucrose diet fed rats showed higher TAG with higher TGSR, lower LPL and higher FCR than those of high-fat diet fed rats. In VMH-lesioned rats, high-fat diet fed rats showed higher TAG with similar TGSR, higher LPL and lower FCR than those of standard diet fed rats. High-sucrose diet fed rats showed markedly higher TAG with notably higher TGSR, higher LPL and lower FCR than those of standard diet fed rats. High-sucrose diet fed rats showed still higher TAG with markedly higher TGSR, similar LPL and higher FCR than those of high-fat diet fed rats. CONCLUSIONS: The mechanism by which TAG metabolism is affected by a high-fat or a high-sucrose diet differed; a high-fat diet increased plasma TAG level by lowering removal of TAG without increase in hepatic TAG secretion in sham-operated (normal) rats. A high-sucrose diet, in contrast, induced much higher plasma TAG levels by both increased hepatic TAG secretion and decreased removal of TAG. The effects of a high-fat or a high-sucrose diet were similar but exaggerated in VMH lesioned animals.

Animals↗
PubMed2001

Association of polymorphic alleles of the calcium-sensing receptor gene with the clinical severity of primary hyperparathyroidism.

OBJECTIVE: Primary hyperparathyroidism (pHPT) is a heterogeneous disease in its clinical course and severity. Previous studies have suggested an association between the clinical severity of pHPT and the genotypes of vitamin D receptor, oestrogen receptors and PTH molecules. The Ca-sensing receptor (CaR) is activated by an extracellular calcium ion and controls PTH secretion, and thus polymorphisms of CaR might be associated with the magnitude of PTH secretion and the clinical severity of pHPT. In this study, we examined the relationship between CaR polymorphisms and biochemical markers in pHPT patients. METHODS: We analysed 105 Japanese pHPT patients (85 females and 20 males; mean age 55.6 +/- 14.0 years). We determined the CaR genotypes of G990R and intron 5 polymorphisms with genomic DNA extracted from peripheral lymphocytes. The intron 5 polymorphism was defined as T/T, T/C and C/C. RESULTS: In the G990R polymorphism, serum levels of both intact PTH and alkaline phosphatase (ALP) were significantly higher and the serum level of phosphorus was significantly lower in the RR group than in the GG group. In the intron 5 polymorphism, the T/T group showed significantly lower serum levels of intact PTH and Ca. Furthermore, patients with both the codon 990 RR and the intron 5 C allele (the RRC(+) group) had significantly higher serum levels of intact PTH and ALP than did the other patients. CONCLUSIONS: The present study is the first to show that CaR polymorphisms of G990R and intron 5 were closely associated with the magnitude of PTH secretion and/or PTH degradation as well as the clinical severity in pHPT patients.

Adolescent↗
PubMed2001

Activation of the Sarcophaga lectin gene promoter by (A + T)-stretch binding protein.

Previously, we purified and isolated a cDNA for (A + T)-stretch binding protein (ATBP) that binds to (A + T)-stretches in the 5' upstream region of the Sarcophaga lectin gene [Nakanishi-Matsui, M., Kubo, T. & Natori, S. (1995) Eur. J. Biochem. 230, 396-400]. Here, we used a luciferase reporter to examine the effect of ATBP on transcription of the Sarcophaga lectin gene. Deletion experiments revealed that ATBP activates the Sarcophaga lectin gene in a 5' upstream sequence-dependent manner, and that at least the N-terminal 25 residues, the three Zn-finger domains, an acidic domain and the third hydrophobic domain of ATBP are indispensable for its function. Furthermore, a synergistic effect was detected between ATBP and Dif, suggesting that ATBP is involved in the activation of insect immunity genes.

Animals↗
PubMed2001

The paracrine role of stem cell factor/c-kit signaling in the activation of human melanocytes in ultraviolet-B-induced pigmentation.

The interaction of stem cell factor with its receptor, c-kit, is well known to be critical to the survival of melanocytes. Little is known about the role(s) of the stem cell factor/c-kit interaction in epidermal pigmentation, however. To clarify whether the stem cell factor/c-kit signaling has a paracrine role in ultraviolet-B-induced pigmentation, we determined whether the exposure of human keratinocytes, melanocytes, and the epidermis to ultraviolet B light stimulates the expression of stem cell factor or c-kit at the gene and/or protein levels. We further examined whether interrupting the binding of stem cell factor to c-kit by subepidermal injection of a monoclonal antibody to c-kit affects ultraviolet-B-induced pigmentation in brownish guinea pig skin. When human keratinocytes and melanocytes in culture were exposed to ultraviolet B light, transcripts of stem cell factor and c-kit (as assessed by reverse transcription polymerase chain reaction) and expression of those proteins (by enzyme-linked immunosorbent assay and western blotting) increased significantly and peaked at a dose of 20-40 mJ per cm2. In ultraviolet-B-exposed human epidermis, stem cell factor transcripts and protein expression were also markedly enhanced compared with the nonexposed epidermis. Immunohistochemistry with antibodies to stem cell factor revealed an increased staining in the ultraviolet-B-exposed epidermis, which was accompanied by a slight epidermal hyperplasia. In the course of ultraviolet-B-induced pigmentation of brownish guinea pig skin, the subepidermal injection of c-kit inhibitory antibodies completely abolished the induction of pigmentation in the ultraviolet-B-exposed area, and there was no increase in the number of dihydroxyphenylalanine-positive melanocytes. These findings indicate that the stem cell factor/c-kit signaling is critically involved in the biologic mechanism of ultraviolet-B-induced pigmentation.

Animals↗
PubMed2001

Unicompartmental knee arthroplasty for lateral gonarthrosis: midterm results.

Thirty-eight lateral compartment arthroplasties were performed in 22 years. Eighteen joints in 17 patients with an average age of 64.5 years were evaluated with minimum 5-year follow-up. Using the Hospital for Special Surgery knee score, 16 of 18 joints had satisfactory results in terms of function and pain relief. The average preoperative alignment on standing was 14.9 degrees of valgus angulation, which was corrected to 6.9 degrees of valgus. On radiographic analysis, no radiolucent lines were seen under the tibial component, but the femoral component was loose in 1 joint. Although 5 joints showed slight deterioration of osteoarthritic change in the medial compartment, lateral compartment arthroplasty is a reliable and successful option in the treatment of patients with a low level of physical activity.

Aged↗
PubMed2001

The effect of nutritional status on morbidity in COPD patients undergoing bilateral lung reduction surgery.

BACKGROUND: Although candidates for lung reduction surgery (LRS) include malnourished patients with severe chronic obstructive pulmonary disease (COPD), the impact of preoperative nutritional status on surgical outcome has not been clearly elucidated. METHODS: We investigated the relationship between preoperative nutritional status and postoperative morbidity in 23 consecutive patients undergoing LRS. The percentage of ideal body weight (%IBW) and body mass index (BMI) were calculated, and fat-free mass (FFM) and fat mass (FM) were measured using a bioelectrical impedance analyzer. FFM and FM were expressed as height-normalized indices, FFM index [FFM (kg)/height (m)(2), or FFMI] and FM index [FM (kg)/height (m)(2), or FMI]. Serum levels of total protein and albumin were also determined. RESULTS: 8 patients had major complications. Preoperative %IBW and FFMI were significantly lower among patients with major complications, while no significant differences were observed in pulmonary function, FMI or serum protein. The complication rate was significantly higher among patients with low FFMI (FFMI < or = 16) but not with low %IBW or BMI. CONCLUSION: These results suggest that FFM depletion is an excellent predictor of unacceptable postoperative complication following LRS.

Aged↗
PubMed2001

Osteosarcoma metastatic to the mandible: a case report.

A case of osteosarcoma that metastasized to the mandibular ramus from the femur in a 36-year-old man is presented. The patient was referred to us for the diagnosis and treatment of swelling of the left cheek. Radiologic examination showed a radiolucent lesion containing radiopaque areas within the left mandibular ramus. The patient previously suffered from a femoral small cell osteosarcoma, which was resected 71 months before our first examination. After induction of general anesthesia, a unilateral mandibulectomy and a simultaneous reconstruction using a titanium plate and an artificial condyle were performed. The postoperative course was uneventful, with satisfactory facial appearance and jaw function. The histopathologic features of the mandibular tumor were identical to those of the femoral tumor. Thus the mandibular lesion was diagnosed as a metastatic small cell osteosarcoma. At 27 months after the operation there had been no recurrence.

Adult↗
PubMed2001

Immunohistochemical study of the distribution of endocrine cells in the gastrointestinal tract of the camel (Camelus bactrianus).

The regional distribution and relative frequency of endocrine cells in the gastrointestinal tract of the camel, Camelus bactrianus, were investigated using immunohistochemical methods. Ten types of immunoreactive (IR) endocrine cells were identified in this study. Among these cell types, only serotonin- and somatostatin-IR cells were detected in almost all regions of the gastrointestinal tract. Most of the cell types showed peak density in the pyloric gland region. The others showed restricted distribution: gastrin, cholecystokinin (CCK), motilin, bovine pancreatic polypeptide (BPP), and (gastric) substance P in the stomach; gastrin, CCK, BPP, gastric inhibitory polypeptide (GIP), glucagon, peptide tyrosine tyrosine (PYY) and substance P in the small intestine; and CCK, motilin, BPP, and PYY in the large intestine. Fundamentally the distribution pattern of endocrine cells in the gastrointestinal tract of the camel is similar to that of cattle. The distribution and frequency of endocrine cells in the glandular sac region are the same as those of the cardiac gland.

Animals↗
PubMed2001

First isolation of geranyl disaccharides from ginger and their relations to aroma formation.

Three geraniol glycosides were isolated from immature fresh ginger rhizomes (Zingiber officinale Roscoe). Their structures were identified as geranyl 6-O-alpha-L-arabinopyranosyl-beta-D-glucopyranoside (1) geranyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside (2) and geranyl 6-O-beta-D-xylopyranosyl-beta-D-glucopyranoside (3) by spectrometric analyses. After incubating each glycoside with a crude enzyme solution prepared from ginger, geraniol was liberated in all of those fractions. This result indicates that the glycosides are related to the formation of geraniol-related compounds in ginger aroma.

Acyclic Monoterpenes↗
PubMed2001

Cloning of cDNA for cathepsin B mRNA 3'-untranslated-region-binding protein (CBBP), and characterization of recombinant CBBP.

Previously, we purified the cathepsin B mRNA 3'-untranslated-region-binding protein (CBBP) from Sarcophaga and suggested its participation in the translational regulation of cathepsin B mRNA in this insect. In this study, we isolated a full length cDNA for CBBP. CBBP was an RNA-binding protein that contained four RGG boxes and four zinc finger motifs required for RNA binding. CBBP was shown to be localized in both the nuclei and cytoplasm of Sarcophaga hemocytes. Recombinant CBBP bound to the entire region of cathepsin B mRNA and repressed its translation in vitro.

3' Untranslated Regions↗
PubMed2001

The promoter of mouse transcription repressor bach1 is regulated by Sp1 and trans-activated by Bach1.

The Maf recognition element (MARE) is regulated by both activators and repressors. Bach1 and Bach2 repress MARE-dependent transcription by forming heterodimers with Maf-related oncoproteins. In order to gain an understanding of the regulation of bach1 gene expression, we analyzed the structure of the mouse bach1 gene. Comparison of the exon-intron structure of the bach1 gene with those of other NF-E2-related genes indicated that bach1 and bach2 constitute an evolutionarily distinct subfamily among bZip factors. The bach1 promoter region contains two GC boxes that are important for its basal activity and are bound by Sp1 in K562 cell extracts. In addition, we found an evolutionarily conserved MARE-like element located downstream of the transcription initiation site. Deletion of this element resulted in a higher promoter activity in K562 cells. Bach1 trans-activated its own promoter depending on the presence of the MARE-like element in co-transfection assays. However, Bach1 did not bind to the MARE-like element in electrophoretic mobility shift assays (EMSA). These results suggest that Bach1 activates its own promoter indirectly by inhibiting the putative repressor. Such a positive feedback regulation by the repressor Bach1 may play an important role in maintaining the expression of Bach1 while consolidating repression of other genes with MARE.

Animals↗
PubMed2001

Molecular cloning and characterization of a cDNA for a novel ethylene receptor, NT-ERS1, of tobacco (Nicotiana tabacum L.).

The cDNA encoding a novel member (NT-ERS1) of ethylene receptor family of tobacco (Nicotiana tabacum L.) was obtained by a combination of RT-PCR and 5'-/3'-RACE cloning. The cDNA was 2,092 nucleotides long and had an open reading frame of 1,911 bp encoding 637 amino acids. The deduced polypeptide lacked a response regulator domain, indicating that the ethylene receptor belongs to an ERS-group. The amino acid sequence was similar to respective members of the tobacco ethylene receptor family: 67.8% to NT-ETR1, 39.1% to NTHK1 and 31.1% to NTHK2. Comparison of amino acid sequence suggested that NT-ERS1 is the counterpart of Nr in the ethylene receptor family of tomato, which belongs to Solanaceae as does tobacco. Northern blot analysis showed that mRNA of NT-ERS1 was present in leaf, shoot and root tissues, and accumulated in leaves treated with exogenous ethylene. A mutated NT-ERS1 cDNA transgene, obtained by introducing one nucleotide substitution into NT-ETR1 cDNA, conferred ethylene insensitivity in tobacco plants, indicating that the translation product of the cDNA actually functioned in the plants.

Blotting, Northern↗
PubMed2001

Value of lipiodol computed tomography and digital subtraction angiography in the era of helical biphasic computed tomography as preoperative assessment of hepatocellular carcinoma.

OBJECTIVE: To compare the diagnostic accuracies of Lipiodol computed tomography (CT) and helical biphasic CT as preoperative imaging modalities for hepatocellular carcinoma (HCC). SUMMARY BACKGROUND DATA: Lipiodol CT after digital subtraction angiography has long been used as a highly sensitive imaging modality for HCC. The recent advent of helical CT has allowed scanning the entire liver during both the arterial and portal venous phase of contrast enhancement. METHODS: The authors analyzed data from 164 patients who underwent hepatic resection for HCC to calculate the sensitivity and specificity of these modalities. Findings of intraoperative ultrasonography followed by histologic confirmation were set as the gold standard. RESULTS: Although sensitivity decreased with both modalities as tumors became small and well differentiated, helical CT showed a higher sensitivity than Lipiodol CT in detecting well-differentiated HCC nodules smaller than 2 cm. In contrast, Lipiodol CT was superior to helical CT for the detection of small but moderately to poorly differentiated nodules. The overall sensitivity of helical CT was higher than that of Lipiodol CT. These findings suggest that helical CT is superior in delineating early HCC, whereas Lipiodol CT is specific to the detection of intrahepatic metastases. In terms of specificity, helical CT was superior to Lipiodol CT. CONCLUSIONS: Helical CT and Lipiodol CT are complementary modalities. At present, helical biphasic CT does not obviate the need for invasive techniques such as angiography and Lipiodol CT as preoperative examinations for HCC.

Adult↗