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Biomedical subjects

S Kanazawa

Publications and source records attributed to S Kanazawa.

At least 19 recordsLinked to original sources
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↗
PubMed2000

Assessment of secondary necrosis of Jurkat cells using a new microscopic system and double staining method with annexin V and propidium iodide.

Using a new system developed by us for acquiring microscopic images automatically, we compared the morphological changes that apoptotic cells undergo with changes in the staining pattern of annexin V-enhanced green fluorescent protein (AV-EGFP) and propidium iodide (PI) in individual cells. Jurkat cells were treated with 5 mM CaCl2 alone, anti-Fas antibody and heating at 42 degrees C for 30 min or 46 degrees C for 60 min, and then were incubated in medium with 5 mM CaCl2. Time-lapse DNA fragmentation analysis and morphological observation revealed that the anti-Fas antibody and heating at 42 degrees C for 30 min induced typical apoptosis in the cells, and heating at 46 degrees C for 60 min induced typical necrosis. Time-lapse observation of individual cells stained with AV-EGFP and PI confirmed that apoptotic cells were stained at first with AV-EGFP alone, and thereafter also with PI when the cellular membrane ruptured and the cell underwent secondary necrosis. Most of the cells which underwent necrosis were stained simultaneously with AV-EGFP and PI. There was a significant time interval between the staining of individual cells with AV-EGFP, indicating apoptosis, and staining of these cells with PI, which indicated the occurrence of secondary necrosis. These results suggest that time-lapse examinations are necessary to distinguish apoptosis, secondary necrosis and necrosis in cells from one another. This study presents direct evidence that apoptotic cells undergo secondary necrosis, which could be recognized with PI.

Annexin A5↗
PubMed2000

Glomosporin, a novel antifungal cyclic depsipeptide from Glomospora sp. I. Production, isolation, physico-chemical properties and biological activities.

A novel antifungal cyclic depsipeptide termed glomosporin, which has a fatty acyl side chain, was isolated from a barley solid culture of Glomospora sp. The strain was isolated from fallen pine leaves collected in Fukusima Prefecture, Japan and identified as Glomospora sp. BAUA 2825. Glomosporin was purified by butanol extraction followed by preparative HPLC. Glomosporin showed antimicrobial activity against fungi including clinically important Aspergillus fumigatus.

Animals↗
PubMed2000

Novel human topoisomerase I inhibitors, topopyrones A, B, C and D. I. Producing strain, fermentation, isolation, physico-chemical properties and biological activity.

In the course of a screening program for specific inhibitors of human topoisomerase I using a recombinant yeast, we have discovered four new active compounds. All four compounds were isolated from the culture broth of a fungus, Phoma sp. BAUA2861, and two of them were isolated from the culture broth of a fungus, Penicillium sp. BAUA4206. We designated these compounds as topopyrones A, B, C and D. Topopyrones A, B, C and D selectively inhibited recombinant yeast growth dependent on expression of human topoisomerase I with IC50 values of 1.22, 0.15, 4.88 and 19.63 ng/ml, respectively. The activity and selectivity of topopyrone B were comparable to those of camptothecin. The relaxation of supercoiled pBR322 DNA by human DNA topoisomerase I was inhibited by these compounds, however they did not inhibit human DNA topoisomerase II. Topopyrones A, B, C and D were cytotoxic to all tumor cell lines when tested in vitro. Topopyrone B has potent inhibitory activity against herpesvirus, especially varicella zoster virus (VZV). It inhibited VZV growth with EC50 value of 0.038 microg/ml, which is 24-fold stronger than that of acyclovir (0.9 microg/ml). Topopyrones A, B, and C were inhibitory to Gram-positive bacteria.

Anthraquinones↗
PubMed2000

Novel human topoisomerase I inhibitors, topopyrones A, B, C and D. II. Structure elucidation.

The structures of novel topoisomerase I inhibitors, topopyrones A, B, C and D were elucidated by spectral analysis of the chemical derivatives. These compounds are an anthraquinone type containing a fused 1,4-pyrone moiety. Topopyrones A and B contain a chlorine atom, however C and D do not. It was suggested that topopyrones B and D are converted from topopyrones A and C, respectively by Wessely-Moser type rearrangement.

Anthraquinones↗
PubMed2000

[CT-guided needle biopsy in malignant lymphoma: current techniques and its usefulness].

Histological examination of adequate biopsy specimens is fundamental to the management of patients with malignant lymphoma. Core-needle biopsy with computed tomography potentially provides a better basis for this assessment. Image-guided needle biopsy should be the first procedure performed in the diagnosis of lymphoma, except in easily accessible superficial neck, inguinal, and axillary nodal sites. Recent studies have shown a diagnostic accuracy of 83% to 87%. We describe the biopsy technique that have been successful in our personal experience. From our experience, CT-guided core-needle biopsies prove sufficient information for the diagnosis of and subsequent therapeutic decision to treat most cases of lymphoma.

Biopsy, Needle↗
PubMed2000

[Biopsy].

We reviewed the current devices, techniques, guiding images, indications and complications of needle biopsy with CT guidance. The development of new devices such as automated cutting needle has enabled radiologists to obtain tissue specimens of good quality at biopsy. Techniques such as the tandem or coaxial method ensure more a more accurate biopsy route. And helical CT and CT fluoroscopy have markedly shortened the time required for needle biopsy. However, we sometimes encounter minor complications, and rarely major ones, during and after needle biopsy. Some of these complications may be caused by malpractice. Therefore it is important always to pay attention to the possibility of complications of needle biopsy and to minimize radiation exposures from CT fluoroscopy.

Biopsy, Needle↗