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Biomedical subjects

K Yoshikawa

Publications and source records attributed to K Yoshikawa.

At least 253 records · Page 14Linked to original sources
PubMed1998

Cloning and sequencing of BeS-1 gene encoding the immunogenic antigen of Streptococcus sanguis KTH-1 isolated from the patients with Behçet's disease.

In order to analyze the immunopathologic mechanisms of Behçet's disease, the gene (bes-1) encoding a streptococcal antigen correlated with the disease was cloned and sequenced, and protein produced by this clone was identified by Western immunoblotting using serum antibody from the patient. Cellular DNA of Streptococcus (S.) sanguis serotype KTH-1 (uncommon serotype 1, strain 113-20) from the patient was extracted and digested with EcoRI. The digested fragments were cloned into the cloning vector lambda gt11, and then the resulting DNA library was immunoscreened using the patient's serum antibody to serotype KTH-1. The immunopositive clone of the 1.5 kbp fragment was subcloned into pUC 118 plasmid (pU8BeS1-1) and sequenced. The sequence showed that the 3'-terminal half side region of this insert contained 962bp of open-reading frame (ORF) discontinued at the EcoRI restriction site, and the stop codon was not found. The nucleotide sequence of the remaining additional 3'-terminal region of this gene encoding whole BES-1 was determined by genome walking. The whole ORF of bes-1 consisted of 849 amino acid residues with a calculated molecular mass of 95 kDa. The residues in a portion of the amino acid sequence showed a 60% correspondence to those of the human intraocular peptide Brn-3b.

Amino Acid Sequence↗
PubMed1998

Four acylated triterpenoid saponins from Albizia procera.

Four new oleanane-type triterpene glycosides, proceraosides A-D (1-4), were isolated from the seeds of Albizia procera. Their structures were established by extensive NMR experiments and chemical methods. Compounds 1-3 comprised acacic acid as the aglycon and a monoterpenic carboxylic acid linked to a monoterpene quinovoside as the acyl moiety at C-21. The common oligosaccharide moiety linked to C-28 in 1-3 was determined as alpha-l-arabino- furanosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->3)]-alpha-L-rhamnopyranosy l- (1-->2)-beta-D-glucopyranosyl ester. These compounds differed in the C-3-linked sugar unit or in the configuration of C-6' of the inner monoterpene moiety in the C-21-linked acyl unit. Compound 4 was established as the 16-deoxy analogue of 1.

Carbohydrate Sequence↗
PubMed1998

Isolation and absolute structures of enantiomeric 1,2-bis(4-hydroxy-3-methoxyphenyl)-1,3-propanediol 1-O-glucosides from the bark of Hovenia trichocarpa.

Two 1,2-bis(4-hydroxy-3-methoxyphenyl)-1,3-propanediol 1-O-glucosides, hovetrichosides A (1) and B (2), were isolated from the bark of Hovenia trichocarpa. Their structures were established by extensive NMR experiments and chemical methods. Compounds 1 and 2 were (1R), (2S)-1-(4-hydroxy-3-methoxyphenyl)-2-(4-hydroxy-3-methoxyphenyl)-1, 3-propanediol 1-O-beta-D-glucopyranoside and (1S), (2R)-1-(4-hydroxy-3-methoxyphenyl)-2-(4-hydroxy-3-methoxyphenyl)-1, 3-propanediol 1-O-beta-D-glucopyranoside, respectively.

Glucosides↗
PubMed1998

Association between restriction fragment length polymorphism of the L-myc gene and susceptibility to gastric cancer.

BACKGROUND: L-myc polymorphism has been documented to be a representative genetic trait which is related an individual's susceptibility to several cancers. However, there have been no reports concerning any significant association between susceptibility to gastric cancer and L-myc polymorphism. METHODS: The distribution of L-myc polymorphism in 61 patients with gastric cancer was determined by polymerase chain reaction-based restriction fragment length polymorphism and compared with that of 107 healthy control subjects. RESULTS: There was a significant difference in the distribution of both genotypes (P = 0.024) and allele frequencies (P = 0.026) between the two groups. The relative risk of gastric cancer for genotypes with the shorter (S) allele was 3.09 compared with the longer (L) allele homozygote. No significant correlation with clinicopathological features of the cancers except for prognosis was found. The patients with SS genotypes had a worse prognosis than those with LL or LS genotypes (P = 0.029). CONCLUSION: L-myc polymorphism may be significant in an individual's susceptibility to gastric cancer in Japan, and may be a useful marker for identifying patients at high risk of developing gastric cancer.

Disease Susceptibility↗
PubMed1998

Immunological study on CD3 defective cutaneous T cell lymphoma cells from a patient with Sézary syndrome.

Here we investigated the nature of cutaneous T cell lymphoma (CTCL) cells lacking surface CD3. A large number of CD3- CD4 T cells were found in the peripheral blood and lesional skin of a patient with Sézary syndrome, which is a variant of CTCL. Southern blot analysis revealed that a clonal rearrangement of T cell receptor (TCR) genes was detected in the separated CD3- CD4 cells, whereas CD3+ CD4 cells showed no clonal rearrangement, indicating that the CD3- CD4 cells represented CTCL cells. However, the CTCL cells expressed TCR with a particular Vbeta apart from CD3. The CTCL cells showed significant responses to staphylococcal enterotoxins (SEs) in vitro, although they hardly responded to phytohaemagglutinin, Mycobacterium tuberculosis antigen, and alloantigen. They required antigen-presenting cells (APC) to respond to SEB. Blocking analyses with MoAbs revealed that they recognized SEB through TCR depending on HLA-DR and intercellular adhesion molecule-1 (ICAM-1). Taken collectively, these results indicate that the CTCL cells lacking surface CD3 could proliferate in response to bacterial superantigens, whereas the responses to conventional antigens were generally suppressed. These results also implied that CTCL could be exacerbated by bacterial infection.

Antigen-Presenting Cells↗
PubMed1998

Endogenous EGF-family growth factors are necessary for the progression from the G1 to S phase in human keratinocytes.

Recently several endogenous epidermal growth factor (EGF)-family growth factors (transforming growth factor-alpha, amphiregulin, and heparin-binding EGF-like growth factor) have been identified in human keratinocytes. These factors are known to play an important role in the regulation of cell proliferation. Here we show that the interaction between these factors and EGF receptor are key factors in the progression from the G1 phase to the S phase (the G1/S progression) in human keratinocytes. In this study, human keratinocytes were cultured in serum-free MCDB153 medium and then partially synchronized by isoleucine deprivation. After synchronization, the number of S phase cells increased and reached a maximum after 18-24 h. The immediate addition of anti-EGF receptor blocking antibody (1 microg per ml) to synchronized cells decreased S phase cells by 42.5% compared with untreated keratinocytes at 18 h. By contrast, the addition of anti-EGF receptor antibodies at 12 h or later did not alter the percentage of S phase cells. Northern blot analysis of synchronized cells demonstrated that mRNA expression of transforming growth factor-alpha, amphiregulin, heparin-binding EGF-like growth factor, and EGF receptor reached a maximum within 0.5-3 h after synchronization, when many cells initiated progression from the G1 to the S phase. The results show that anti-EGF receptor antibodies block the G1/S progression and the rapid increase of mRNA expression of endogenous EGF-family growth factors and EGF receptor during G1/S progression. These findings indicate that growth factor binding and EGF receptor activation are involved in the G1/S cell cycle progression of human keratinocytes.

Amphiregulin↗
PubMed1998

Surveillance study for clinical stage I testicular seminomas and nonseminomatous germ cell tumors.

BACKGROUND: Optimal therapy for stage I testicular tumors is still controversial. This study evaluated the efficacy of a surveillance policy for patients with testicular stage I seminomas and nonseminomatous germ cell tumors (NSGCT). METHODS: From 1984 to 1996, 24 patients with stage I seminoma and 20 with stage INSGCT were followed after radical orchiectomy with tumor markers and imaging studies. All patients were followed for at least 2 years except for those who recurred within 2 years. Recurrent patients were treated with cisplatin-based chemotherapy. RESULTS: The median follow-up periods for seminoma and NSGCT patients were 41 and 54 months, respectively. Recurrences were detected in 2 seminoma (8.3%) and 10 NSGCT (50%) patients. Eleven of the 12 recurrent patients (92%) were detected within 2 years after orchiectomy. The seminoma patients both recurred in the retroperitoneal lymph nodes, while 70% of the NSGCT patients recurred in the lung and/or retroperitoneal lymph nodes. The recurrent seminoma patients were treated with chemotherapy and are alive without disease for 1 7 and 24 months afterorchiectomy. One NSGCT patient died of cancer, but the other 9 recurrent NSGCT patients are alive without disease at 25 to 113 months after orchiectomy. CONCLUSIONS: Surveillance alone is reliable for monitoring patients with stage I testicular seminoma and NSGCT. The majority of recurrences occurred within 2 years, necessitating intensive follow-up for 3 years. As the lung metastatic rates in NSGCT patients were high, a more accurate assessment for lung metastasis is desirable in these patients.

Adolescent↗
PubMed1998

Multiple early gastric stump carcinomas after gastrectomy for peptic ulcer.

The remnant stomach after partial gastrectomy is considered to have a predilection for the development of primary gastric carcinoma. However, early gastric stump carcinomas are uncommon because the diagnosis of gastric stump carcinoma is more difficult than that of carcinoma in the intact stomach. Triple early gastric stump carcinomas, as in the present case, are exceedingly rare and may provide some clues for further investigation of carcinogenesis in the gastric stump. We studied about the histological appearance, genetic alterations (P-53 gene, c-erbB-2 gene and K-ras gene), and expression of tumor-associated antigens (carcinoembryonic antigen, carbohydrate antigen 19-9, and sialyl-Tn) in this rare case. The three carcinomas differed from each other histologically. With respect to genetic alterations, c-erbB-2 was amplified in one lesion, but no mutations of K-ras and P-53 gene were detected. The three carcinomas also differed from each other on the expression of tumor-associated antigens. In noncancerous mucosal epithelium at the anastomosis showing hyperplasia and cystic formation of glandular epithelial cells, no genetic alterations were detected, but sialyl-Tn and carbohydrate antigen 19-9 were expressed. These results suggest that there may be different processes of carcinogenesis of the three carcinomas even though they occurred under identical environmental conditions to those that have increased cancer risk.

Adenocarcinoma↗
PubMed1998

[A clinical investigation of bacteremia for the past ten years at the Second Department of Internal Medicine, Jikei University Hospital].

We clinically investigated a total of 288 cases of bacteremia for the past ten years, from January 1986 to December 1995, at the Second Department of Internal Medicine in the jikei University Hospital. All of the subjects who had a positive reaction to blood culture or catheter tip culture were investigated for their basic disease, complications, and detected bacteria. Malignant tumors, chronic renal failure, diabetes mellitus, and hematologic disease were frequent by noted. The cases due to primary infection were mainly respiratory organ infection or urinary tract infection, which were 47.8% of the total. In 31.3% of the total, catheter tip cultures were positive. Except for catheter related infection, Gram-positive coccus were detected in 40.3%, which was most frequent. Methicillin resistant Staphylococcus aureus (MRSA) were 8.1% and Staphylococcus epidermidis were 11.2%. In catheter related infection, Gram-positive coccus were detected in 59.9%, which was most frequent amongst them, MRSA was 17.2%, S. epidermidis was 16.2%. The mortality of bacteremia was 12.5%, mainly from hematologic diseases, immunodeficiency due to long term steroid administration etc. Accordingly, the more the advance of chemotherapy, the better the prognosis of septicemia is. Appearance of catheter related infection was unexpected frequent. Increase of immunocompromised host is thought to be one of the main factors in the outbreak of bacteremia.

Adolescent↗
PubMed1998

Eccrine syringofibroadenoma: report of a case and analysis of cytokeratin expression.

Eccrine syringofibroadenoma (ESFA) is a rare disorder which shows differentiation toward the eccrine sweat apparatus. There is a controversy concerning the pathogenesis and precise differentiation of this tumor. We report a case of ESFA and its differentiation pattern by an analysis of cytokeratin expression. Using paraffin-embedded materials, histopathological and immunohistochemical studies were performed. Staining patterns of the luminal, peripheral, and inner cells of the tumor strands closely matched or mimicked those of the luminal, outer and intermediate cells of the normal eccrine dermal duct, respectively. The case of ESFA reported revealed a pattern of differentiation suggestive of an eccrine duct origin.

Adenoma, Sweat Gland↗
PubMed1998

Muscarinic cholinergic receptors in human narcolepsy: a PET study.

OBJECTIVES: To investigate the function of the muscarinic cholinergic receptor (mAchR) in narcolepsy and the effects of pharmacotherapy on mAchRs. BACKGROUND: Muscarinic neural transmission serves as the main executive system in REM sleep. Studies in canine narcolepsy reported an increase in mAchRs in the pons. METHODS: The mAchRs of 11 drug naive/free patients with narcolepsy and 21 normal controls were investigated using PET with [11C]N-methyl-4-piperidylbenzilate ([11C]NMPB). Measurements were done in the pons, thalamus, striatum, and cerebral cortex. Seven of the 11 patients also underwent additional PET scans after the alleviation of symptoms by pharmacotherapy. RESULTS: There were no differences in [11C]NMPB binding between the control and drug naive/free patients in all areas analyzed. At the time of on-medication PET scan, [11C]NMPB binding in the thalamus was decreased, but only to a small degree compared with that by anticholinergic drugs. CONCLUSION: The present results do not support the notion that the mAchR is the main site of action of pharmacotherapy in the marked clinical improvement of human cataplexy.

Adult↗
PubMed1998

Pregnane glycosides, gymnepregosides A-F from the roots of Gymnema alternifolium.

The structural elucidation of six new related polyoxypregnane glycosides, gymnepregosides A (1), B (2), C (3), D (4), E (5) and F (6), together with two known compounds, from the roots of Gymnema alternifolium (Asclepiadaceae) was achieved through on a detailed study of 1H- and 13C-NMR spectral data and chemical means. The results obtained for new compounds, 1-6, show that they are (20S)-pregn-6-ene-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta,20-heptaol or sarcostin 3-O-glycosides, and all the sugars at C-3 are beta(1-->4)-linked. Some of them possessed benzoyl, cinnamoyl and tigloyl residues as the ester linkages located at C-12 and/or C-20 of the aglycon.

Carbohydrate Sequence↗