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Biomedical subjects

S Kanazawa

Publications and source records attributed to S Kanazawa.

At least 37 records · Page 2Linked to original sources
PubMed2001

Preliminary report: effect of adrenal androgen and estrogen on bone maturation and bone mineral density.

To clarify the independent physiological roles of adrenal androgen and estrogen on bone growth, we compared the lumbar spine bone mineral density (BMD) in prepubertal girls with virilizing congenital adrenal hyperplasia (CAH) (n = 17) and girls with central precocious puberty (CPP) (n = 18). When BMD was analyzed according to chronologic age, no significant differences were found between CPP and CAH patients. However, when adjusted to bone age, BMD was statistically higher in CAH than in CPP subjects. This finding suggests that adrenal androgen, as well as estrogen, plays an important role in increasing BMD. Adrenal androgen may act on bone not only as androgen, but as estrogen after having been metabolized into an aromatized bone-active compound in peripheral tissues, such as bone and fat. Therefore, adrenal androgen may have a more important role in increasing BMD than previously realized.

Absorptiometry, Photon↗
PubMed2001

Immunohistochemical study of p53, p21 and PCNA in pterygium.

Since mutated p53 is one of the most frequent gene abnormalities in human cancer, we hypothesized that mutation of p53 may play an important role in growth and recurrence of pterygia, a dysplasia of the conjunctiva. Therefore, we compared pterygia of Japanese and Tunisian patients using antibodies against p53, p21 and proliferating cell nuclear antigen (PCNA). In Nagasaki, 21 pterygia of Japanese individuals were removed and in Gabes, 19 primary pterygia of Tunisian individuals. Positive staining of wild type p53 was not found in the Japanese pterygia, whereas 38.1% were positive for mutant p53, none were positive for p21 and 76.2% were positive for PCNA. The incidence of mutant p53-positive staining was 50.0% in males and 22.2% in females, which was statistically significant. In the 19 Tunisian patients, positive staining of wild type p53 was not found, whereas 36.8% were positive for mutant p53, 0% for p21 and 63.1% for PCNA. Differences between Japanese patients and Tunisian patients were not significant. There were 2 types of pterygium. One type did not show mutant p53 and the other showed mutant p53 caused by ultraviolet light. However, damage caused by p53-dependent programmed cell death of pterygium cells may lead to mutations in other genes which may allow the progressive multistep development of limbal tumors. It is possible that mutant p53-positive pterygia can develop into limbal tumors.

Adult↗
PubMed2001

Combinations of dominant-negative class II transactivator, p300 or CDK9 proteins block the expression of MHC II genes.

The class II transactivator (CIITA) regulates not only the transcription of HLA-DR, -DQ, -DP, but also invariant chain, DMA and DMB genes. A hybrid mutant CIITA protein, which contained residues from positions 302 to 1130 in CIITA fused to the enhanced green fluorescent protein (EdCIITA), inhibited the function of the wild-type protein. EdCIITA extinguished the inducible and constitutive expression of MHC II genes in epithelial cells treated with IFN-gamma and B lymphoblastoid cells respectively. Also, it blocked T cell activation by superantigen. This inhibition correlated with the localization of EdCIITA but not CIITA in the cytoplasm of cells. However, when EdCIITA was co-expressed with a dominant-negative form of the nucleoporin Nup214/CAN, it also accumulated in the nucleus. These data suggest that EdCIITA not only competes with the wild-type protein for the binding to MHC II promoters but sequesters a critical co-factor of CIITA in the cytoplasm. CIITA also recruits the histone acetyltransferase cAMP responsive element binding protein (CREB) binding protein and positive transcription elongation factor b (p-TEFb) for the transcription of MHC II genes. Dominant-negative p300 (DNp300) or CDK9 (DNCDK9) proteins inhibited the function of CIITA and of the DRA promoter. Thus, combinations of EdCIITA and DNp300 and/or DNCDK9 proteins extinguished the transcription of MHC II genes. They might become useful for future genetic therapeutic approaches in organ transplantation and autoimmune diseases.

Animals↗
PubMed2001

VEGF, basic-FGF, and TGF-beta in Crohn's disease and ulcerative colitis: a novel mechanism of chronic intestinal inflammation.

OBJECTIVE: Inflammatory bowel disease (IBD), the precise etiology of which remains unknown, is comprised of two forms of chronic intestinal inflammation; ulcerative colitis (UC) and Crohn's disease (CD). Recent evidence increasingly suggests that IBD is the result of dysfunctional immunoregulation manifested by inappropriate production of mucosal cytokines. An abnormal microcirculatory system has also been implicated in its pathogenesis. To elucidate the mechanism of ischemic change in IBD, we assesse serum concentration levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF), and plasma level of endothelin-1 (ET-1). We also investigated the expression of VEGF, b-FGF, and transforming growth factor-beta1,2,3 (TGF-beta1,2,3) in tissue by immunostaining. METHODS: Blood samples were obtained from 11 patients with UC, 11 patients with CD, and 10 patients as controls. Paraffin-embedded samples were used for an immunohistochemical study. RESULTS: The concentration levels (in picograms per milliliter) were as follows: for ET-1, UC: 127+/-47.0, CD: 167.3+/-35.1, and controls (asthma: 38.5+/-23.8, p < 0.01; diverticulitis: 40.5+/-25.6, p < 0.01), for b-FGF, UC: 9.2+/-1.9, CD: 9.1+/-1.5, and controls (asthma: 5.0+/-0, p < 0.01; diverticulitis: 5.0+/-0, p < 0.01), for VEGF, UC: 659.8+/-181.0, CD: 740.0+/-182.3, and controls (asthma: 193.7+/-58.7, p < 0.01; diverticulitis: 199.6+/-59.7, p < 0.01). The levels of VEGF and b-FGF were significantly higher in active IBD than those in the controls. There was a significant positive correlation among the serum levels of VEGF and b-FGF and the plasma level of ET-1; that is, elevated VEGF, b-FGF, and ET-1 levels correlated well with each other. Immunohistochemical studies showed increased venula in the submucosa and lamina propria. Overexpression of VEGF and b-FGF in endothelial cells was revealed and TGF-beta2 and TGF-beta3 were found in inflammatory cells of active IBD, but no change was observed around the vessels in the controls. CONCLUSIONS: It is suggested that the reciprocal reaction of these cytokines may contribute to angiogenesis in IBD b inducing intestinal ischemia through vasoconstriction.

Adult↗
PubMed2001

Altered hepatic hemodynamics caused by temporary occlusion of the right hepatic vein: evaluation with Doppler US in 14 patients.

PURPOSE: To evaluate with Doppler ultrasonography (US) the altered hepatic hemodynamics caused by temporary occlusion of the right hepatic vein. MATERIALS AND METHODS: The study group consisted of 14 patients being considered for hepatic arterial infusion or transarterial embolization. In all patients, maximum peak velocity of the blood flow in the right portal vein was measured with Doppler US before and during the occlusion of the right hepatic vein. In 13 patients, color Doppler US was performed to evaluate Doppler signal in the portal venous branch in the occluded area before and during occlusion. Average peak velocity in the right hepatic artery in eight patients was measured by using a transducer-tipped guide wire before and during occlusion. RESULTS: Maximum peak velocity of the right portal vein significantly decreased with occlusion (P <.01). Hepatic venous occlusion changed the Doppler signal in the portal venous branch in the occluded area from hepatopetal to no signal in 10 patients; to weakened hepatopetal in two; and to hepatofugal in one. Average peak velocity of the right hepatic artery showed a decrease or plateau for 15-30 seconds after the start of occlusion and then a rapid increase to reach a plateau at around 75-90 seconds, with 1.5-2 times as much velocity as that before occlusion. CONCLUSION: Increase in hepatic arterial velocity is accompanied by a decrease in the portal velocity with temporary occlusion of the right hepatic vein; the expected increased drainage through the portal vein was almost undetectable.

Aged↗
PubMed2001

Recanalization 24 months after endovascular repair of a large internal iliac artery aneurysm with use of stent-graft.

An 83-year-old man with a large internal iliac artery aneurysm (IIAA) was treated with the use of stent-graft, suggesting successful results at 3, 6, and 12 months after treatment. However, 24-month follow-up computed tomography showed minor peripheral opacification of the IIAA. The patient underwent surgical endoaneurysmorrhaphy. No previous report of long-term recanalization of a satisfactorily thrombosed iliac artery aneurysm at 2 years or more after stent-grafting has been previously reported. Further follow-up studies need to be performed on the present procedure before anyone can confidently recommend it in regard to its long-term safety.

Aged↗
PubMed2001

The effect of calcium on Fas-mediated apoptosis and secondary necrosis of Jurkat cells.

Our previous study using a new microscopic system indicated that apoptotic cells undergo secondary necrosis during treatment with anti-Fas antibody and calcium. In this study, we compared the time-lapse appearance of apoptosis and secondary necrosis of Jurkat cells during treatment with anti-Fas antibody with and without calcium in individual cells. Apoptosis developed in 97% and 81% of cells during 36-hour-treatment with anti-Fas antibody with and without calcium, respectively. The apoptosis of Jurkat cells showed a characteristic pattern of time-lapse morphological change. Less than 1% of the apoptotic cells divided into apoptotic bodies. There was budding in all the other apoptotic cells, but no apoptotic bodies formed. We confirmed that secondary necrosis occurs in individual apoptotic cells during treatment with anti-Fas antibody. Neither the pattern of time-lapse morphological change nor the time interval between the beginning of apoptotic budding and secondary necrosis were related to the presence of calcium. This study clarified the characteristic pattern of time-lapse morphological change in Jurkat cells during treatment with anti-Fas antibody, and presented direct evidence that individual apoptotic cells undergo secondary necrosis. The presence of calcium did not affect the pattern of morphological change or the time interval between the beginning of apoptotic budding and secondary necrosis.

Apoptosis↗
PubMed2000

Scientific discoveries as cultural displays: a further test of Miller's courtship model.

The biographies of 280 scientists demonstrate that the age distribution of their career peaks is identical to those of jazz musicians, painters, and writers, and that this universal age profile holds only among scientists who were married some time in their lives. I interpret this as support for Miller's cultural display model in an evolutionarily novel environment.

Journal Article↗
PubMed2000

Teaching may be hazardous to your marriage.

Kenrick et al.'s experiments demonstrate that men who view photographs of physically attractive women or Playboy centerfolds subsequently find their current mates less physically attractive and become less satisfied with their current relationships. What then would be the cumulative effect of being exposed to young, attractive women on a daily basis? Would there be any real consequences to the men's dissatisfaction with their relationships? Secondary school teachers and college professors come in contact with more young women at the peak of their reproductive value than others do. The analysis of a large, representative data set from the United States indicates that, while men in general are less likely to be divorced than women, and secondary school teachers and college professors in general are less likely to be divorced than others, simultaneously being male and being a secondary school teacher or college professor statistically increases the likelihood of being divorced (p <.05). We contend that the contrast effect that Kenrick et al. find in their experiments is cumulative and has real consequences.

Journal Article↗
PubMed2000

Nontumorous decrease in Tc-99m GSA accumulation.

Nontutimorous decrease in 99mTc-GSA accumulation has not been well covered in the literature. Understanding of this phenomenon is, however, essential for accurate evaluation of regional hepatic function. Scintigrams (transaxial SPECT) of 269 patients who underwent 99mTc-GSA liver scintigraphy were reviewed for the presence of nontumorous decreases in 99mTc-GSA accumulation. Nontumorous decreases in 99mTc-GSA accumulation were seen in 32 of 269 patients (12%). In 16 of the 32 patients (6%), nontumorous decreases in 99mTc-GSA accumulation corresponded to regional decrease in portal venous flow. The causes of such decrease in portal venous flow were portal thrombus of hepatocellular carcinomas in eight patients, portal venous stenosis or occlusion by hilar cholangiocarcinomas in five patients, inter alia. In eight patients (3%), the regions with decreased 99mTc-GSA accumulation correlated with massive hepatic necrosis in fulminant hepatitis, scar in hepatitis, or confleuent in portal venous flow, lobar biliary stasis, or both. In four patients (1.5%), the exact causes of nontumorous decrease in 99mTc-GSA accumulation could not be determined.

Adult↗
PubMed2000

Pulmonary sequestration associated with aspergillosis.

Pulmonary sequestration involves an abnormal pulmonary tissue separated from the normal pulmonary parenchyma, not connected to the tracheobronchial tree and supplied by a systemic artery. A case of intralobar pulmonary sequestration is presented. Case; a 49-year-old male was admitted to our hospital complaining of fever, cough and sputum production. Sputum culture resulted in a large growth of Aspergillus niger. Angiography showed an abnormal blood supply from the abdominal aorta to the right lower lobe. Right lower lobectomy was performed. The postoperative courses are uneventful.

Aspergillosis↗
PubMed2000

Genetically distinct autosomal dominant posterior polar cataract in a four-generation Japanese family.

PURPOSE: To describe the clinical findings of a form of posterior polar cataract in a large Japanese family and to determine whether the posterior polar cataract is causally related to other autosomal dominant cataracts with known genes, chromosomal locations, or both. METHODS: Systemic and ocular histories were obtained and comprehensive ophthalmic examinations were performed in 15 of 37 members of the Japanese family. The posterior polar cataract was transmitted in an autosomal dominant manner through four generations. Although there is some variation in the degree of opacification, the posterior polar cataract in this family is characterized by progressive disk-shaped posterior subcapsular opacities. Genetic linkage analysis was performed with 41 polymorphic microsatellite markers located in chromosomal regions known for linkage to cataracts. Genomic DNA extracted from the 15 individuals was amplified by polymerase chain reaction, the genotype at the marker loci was determined in each family member, and the lod score was calculated at each locus. RESULTS: Significant linkage of the posterior polar cataract was ruled out from the following 10 loci or chromosomal regions: 16q22 and 1p36, to which two forms of autosomal dominant posterior polar cataract have been assigned: 1q21-q25, 2q33-q35, 13cen, 17p13, 17q11-q12, 17q24, 21q22, and 22q, which are the regions responsible for other autosomal dominant congenital cataracts. CONCLUSIONS: This study confirms the genetic heterogeneity of autosomal dominant posterior polar cataracts and demonstrates that the posterior polar cataract in this Japanese family is phenotypically and genetically distinct from previously mapped cataracts.

Adolescent↗
PubMed2000

Tat competes with CIITA for the binding to P-TEFb and blocks the expression of MHC class II genes in HIV infection.

AIDS and the bare lymphocyte syndrome (BLS) are severe combined immunodeficiencies. BLS results from mutations in genes that regulate the expression of class II major histocompatibility (MHC II) determinants. One of these is the class II transactivator (CIITA). HIV and its transcriptional transactivator (Tat) also block the expression of MHC II genes. By binding to the same surface in the cyclin T1, which together with CDK9 forms the positive transcription elongation factor b (P-TEFb) complex, Tat inhibits CIITA. CIITA can also activate transcription when tethered artificially to RNA. Moreover, a dominant-negative CDK9 protein inhibits the activity of MHC II promoters. Thus, CIITA is a novel cellular coactivator that binds to P-TEFb for the expression of its target genes.

Animals↗
PubMed2000

Effects of medical education on attitudes towards mental illness among medical students: a five-year follow-up study.

In order to clarify the effects of medical education on attitudes towards mental illness among medical students, a follow-up study was conducted. All 100 students entering Kochi Medical School in 1988 were subjects. The initial questionnaire survey was conducted in 1988, and followed up in 1993. Response rate was 69% in the initial survey, and 83% in the follow-up study. By the time of the follow-up, all of the students had completed their medical education, including courses in psychiatry and mental health. Results were as follows: At the follow-up study, 1) a significantly higher percentage of students replied that they accepted the mentally ill as co-workers; 2) significantly favorable changes were observed in attitudes towards psychiatric services; 3) optimism about the effectiveness of treatment for mental illness at an early stage and prevention of mental illness had decreased; and 4) no change was observed in attitudes toward human rights of the mentally ill, except in the case of one item stating that the mentally ill should not have children in order to avoid hereditary handicaps, with which a lower percentage agreed. Conclusively, medical education can play an important role in attitudes towards mental illness.

Attitude of Health Personnel↗