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Biomedical subjects

N Hanzawa

Publications and source records attributed to N Hanzawa.

12 recordsLinked to original sources
PubMed1998

Loss of heterozygosity of NF1 gene in juvenile chronic myelogenous leukemia with neurofibromatosis type 1.

To investigate a genetic relation between juvenile chronic myelogenous leukemia (JCML) and neurofibromatosis type 1 (NF-1), we analyzed the NF1 gene in the leukemic cells of a JCML patient with NF-1. We found a point mutation in exon 29 of one allele and a deletion of the other normal allele in the leukemic cells. The point mutation is considered a germline mutation because it was also detected in fibroblasts obtained from the bone marrow of the patient and the peripheral blood mononuclear cells from a sibling. A loss of heterozygosity of NF1 gene may contribute to the progression of leukemia in NF-1 patients.

Alleles↗
PubMed1997

Progressive decrease in hair diameter in Japanese with male pattern baldness.

Fifty-six Japanese with male pattern baldness were evaluated for changes in their hair diameters over three years. The mean hair diameter significantly decreased each year. The average decrease was 1.1 microns per year. Although the percentage of vellus hair increased by 3.6% over three years, this increase rate was lower than that found in Caucasians. To precisely examine the change in hair diameter, the mean distribution of this diameter was investigated. At the beginning of the study, clear peaks were observed at 95 microns in the twenties and 45 microns in the fifties. The number of thicker hairs decreased and the high frequency peak shifted to a thinner hair diameter over 3 years. To quantify the change in the distribution of hair diameter, the percentage of hairs of more than 60 microns was examined. There was a statistically significant 5.61% decrease in the percentage of hairs with a diameter of more than 60 microns over three years. Our findings suggest that the progression of male pattern baldness in Japanese is slower than that of Caucasians and that the percentage of hairs of more than 60 microns is a sensitive index to evaluate the progression of male pattern baldness and the effects of hair growth or hair loss preventive agents.

Adult↗
PubMed1996

Involvement of Fyn tyrosine kinase in progression of cytokinesis of B lymphocyte progenitor.

We analyzed the role of Fyn tyrosine kinase in cell cycle progression of B lymphocyte progenitor (pro B cell). Whereas there were no substantial defects in the intramarrow B cell genesis in the fyn(-) mouse, and long-term proliferation of fyn(-) pro B cells was maintained in vitro under a serum containing culture condition, the cell cycle was arrested at G2/M upon serum deprivation. Morphological analyses demonstrated that the cytokinesis of fyn(-) pro B cells was retarded in the presence of serum and that the entry of fyn(-) pro B cells into late telophase was completely blocked under the serum-free condition. In contrast, the earlier phases of mitosis of fyn(-) pro B cells proceeded normally without FCS. This failure to initiate late telophase resulted in the accumulation of elliptical binucleated cells that might be the outcome of the nuclear division without cytokinesis. Consistent with this defect in the progression of cytokinesis, Fyn was localized in the midspace of dividing pro B cells at anaphase. These results suggested that Fyn localizes at the midspace of dividing pro B cells and regulates the progression of cytokinesis.

Animals↗
PubMed1995

Recognition of consensus CHO structure in ligands for selectins by novel antibody against sialyl Lewis X.

The selectins (L, E, and P) play an important role in the earliest events of the inflammatory response, leading to the "rolling" phenomenon. All selectins react with sialyl Lewis X (SLex) in vitro, possibly suggesting that their ligands have a consensus structure. 2H5 is a monoclonal antibody against SLex that blocks L-selectin-mediated adhesion. 2H5 inhibited adhesion of HL-60 cells to P- and E-selectin-producing COS cells in vitro and immunoprecipitated a P-selectin glycoprotein ligand-1-like glycoprotein from HL-60 cell lysate, suggesting that it recognizes a functional consensus structure on the ligands for all selectins. 2H5 reacted not only with human but also with rat and mouse neutrophils. 2H5 is the first antibody against SLex that recognizes neutrophils of nonhuman mammals. The carbohydrate structure recognized by 2H5 was present not only on high endothelial venules of rat lymphoid organs but also on the endothelial cells of nonlymphoid organs. Furthermore, administration of the antibody markedly inhibited L- and P-selectin-mediated neutrophil rolling and adhesion in rat mesenteric venules in vivo. These results provide evidence for the presence of a consensus carbohydrate structure on the ligands for all selectins. The consensus structure thus has the potential to serve as a therapeutic target.

Animals↗
PubMed1994

Quantitative evaluations of male pattern baldness.

Several methods for the evaluation of hair growth have been reported; however, none of the hitherto reported methods are satisfactory as unbiased double blind studies to evaluate the efficacy of hair growth agents. In the present paper, we describe quantitative evaluation methods for hair growth by measuring the anagen ratio and hair diameters in 56 Japanese subjects aged 23-56 for 3 years. The average anagen ratio decreased by 3.8% in 3 years. The average hair diameters showed a statistically significant decrease each year totalling 3.4 microns. Subjects were sorted according to their anagen ratio into 4 groups. Each group showed different distribution patterns of hair diameters. The higher anagen ratio group has a high frequency peak at thicker hair diameters and the lower anagen ratio group has a high frequency peak at thinner hair diameters. The number of thicker hairs decreased and the high frequency peak shifted to thinner hair diameters in 3 years. These methods are useful to evaluate both the progression of male pattern baldness and the effects of hair growth agents with double blind studies in an unbiased quantitative fashion.

Adult↗
PubMed1994

Growth requirements of hyperthermophilic sulfur-dependent heterotrophic archaea isolated from a shallow submarine geothermal system with reference to their essential amino acids.

Three hyperthermophilic sulfur-dependent heterotrophs were isolated from a shallow submarine hydrothermal system at an inlet of Kodakara-jima island, Kagoshima, Japan. The isolates grew at 60 to 97 degrees C, with the optimum temperatures at 85 to 90 degrees C. Sensitivity to rifampin and the existence of ether lipids indicated that the isolates are hyperthermophilic archaea. Partial sequencing of the genes coding for 16S rRNA showed that the three isolates are closely related to the genus Thermococcus. They grew on proteinaceous mixtures, such as yeast extract, Casamino Acids, and purified proteins (e.g., casein and gelatin), but not on carbohydrates or organic acids as sole carbon and energy sources. Nine amino acids were essential for growth of isolate KS-1 (Thr, Leu, Ile, Val, Met, Phe, His, Tyr, and Arg). Isolate KS-2 required Lys in addition to the nine amino acids, and KS-8 required Lys instead of Tyr. In comparative studies, it was shown that Thermococcus celer DSM 2476 required 10 amino acids (Thr, Leu, Ile, Val, Met, Phe, Tyr, Trp, Lys, and Arg) while Pyrococcus furiosus DSM 3638 required only Ile and Val. The hyperthermophilic fermentative eubacterium Thermotoga neapolitana DSM 4359 did not require any amino acids for growth.

Amino Acids, Essential↗
PubMed1994

The clinical course of acquired aplastic anemia in childhood; a retrospective study.

We reviewed the clinical courses of 38 children with acquired aplastic anemia (AA). The patients were classified according to the severity criteria by the Japanese Ministry of Health and Welfare (JMHW) Study Group (22 severe, 15 moderate, 1 mild). Early death was observed only in severe cases. Eight of the non-severe cases progressed to severe in 0.5-125 months, and the long-term survival rate of non-severe AA did not differ from that of severe AA. The frequency of lymphocytes in the bone marrow was significantly higher, and the peripheral blood neutrophil count was lower in patients who died within a year, and these patients should be treated as very severe. These findings suggest that the JMHW Study Group criteria are useful for identifying AA patients with a poor prognosis, but even non-severe cases should be repeatedly evaluated. Sixteen of the 33 patients treated with corticosteroids and/or anabolic steroids (AS) showed hematological recovery. Bolus methylprednisolone (mPSL) therapy was effective in one of the 8 patients. Allogenic marrow transplant (BMT) was performed on 3 patients. One died from sepsis and engraftment was not achieved in the other two. Trilineage recovery was obtained in 3 of 6 patients treated with rhG-CSF and rhEPO with or without AS, and hemopoiesis has been maintained 6-12 months after discontinuation in 2 cases. In the other 3 patients, the neutrophil count showed transient increase. Therefore, the treatment for severe AA patients, who have no sibling donor for BMT, should be started with the combination therapy including these cytokines.

Adolescent↗
PubMed1993

Mitochondrial DNA polymorphisms in subterranean mole-rats of the Spalax ehrenbergi superspecies in Israel, and its peripheral isolates.

Patterns of mitochondrial DNA (mtDNA) variation were examined in 133 mole-rats constituting all four chromosomal species (2n = 52, 2n = 54, 2n = 58, and 2n = 60) of the Spalax ehrenbergi superspecies in Israel, as well as the peripheral isolates of 2n = 60. In the main range of the complex, a total of 28 mtDNA haplotypes were found in 64 mole-rats, with most haplotypes being unique to either a single chromosomal species or population. mtDNA divergence increased from low to high diploid number in a north-to-south direction in Israel. Overall levels of mtDNA diversity were unexpectedly the highest in the 2n = 60, the youngest species of the complex. The mtDNA haplotypes can be separated into two major groups, 2n = 52-54 and 2n = 58-60, and a phylogenetic analysis for each group revealed evidence of a few haplotypes not sorted by diploid number. The overall patterns of mtDNA divergence seen within and among the four chromosomal species are consistent with the parapatric mode of speciation as suggested from previous studies of allozyme and DNA hybridization. In a separate data set the patterns of mtDNA variation were examined across the main geographic range and across peripheral semi-isolates and isolates of the 2n = 60 chromosomal species. Fifteen haplotypes were found in 69 mole-rats. High levels of mtDNA diversity characterized the main range, semi-isolated, and even some desert isolated populations. The peripheral isolates contain much mtDNA diversity, including novel haplotypes.

Animals↗
PubMed1993

[Treatment and prognosis after late relapse in childhood acute lymphoblastic leukemia].

We evaluated the clinical courses and laboratory features in 13 late-relapse cases of 55 children with acute lymphoblastic leukemia who had been in complete remission for longer than their years. In 8 of 13 cases, leukemia relapsed in bone marrow; 2 with testicular, 1 with central nervous system and one with ovarian involvement. Further, extramedullary relapse not involving bone marrow occurred in 5 cases (4 testicular and 1 CNS). Late-relapse was more frequently observed in boys (37.5%) than in girls (4.4%). Initial age and leukocyte counts were of no value in predicting late-relapse. The relapse rate in cases initially treated by the VPL regimen was twice that of those by a multi-drug regimen. A second prolonged remission was achieved in 5 of 10 cases by combinations of intensive chemotherapy (modified HEX) and irradiation to the testes or CNS. On the contrary, all late relapse patients initially treated by the multi-drug chemotherapy had a poor outcome. More intensive chemotherapy, including high-dose chemoradiotherapy and bone marrow transplantation, should be employed in this group of patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Genetic control of sex-dependent meiotic recombination in the major histocompatibility complex of the mouse.

Meiotic recombination within the proximal region of the major histocompatibility complex (MHC) of the mouse is not random but occurs in clusters at certain restricted sites, so-called recombinational hotspots. The wm7 haplotype of the MHC, derived from the wild mouse, enhances recombination specifically during female meiosis within a fragment of 1.3 kb of DNA located between the A beta 3 and A beta 2 genes in genetic crosses with laboratory haplotypes. Previous studies revealed no significant strain differences in nucleotide sequences around the hotspot, irrespective of the ability of the strain to enhance the recombination. It appeared that a distant genetic element might, therefore, control the rate of recombination. In the present study, original recombinants whose breakpoints were defined by direct sequencing of PCR-amplified DNAs were tested for the rate of secondary recombination in the crosses with laboratory strains in order to determine the location of such a genetic element. The results clearly demonstrated that the chromosomal segment proximal to the hotspot is essential for enhancement of recombination. Moreover, the male recombination is suppressed by a segment distal to the hotspot.

Alleles↗
PubMed1990

Recombinational hotspot specific to female meiosis in the mouse major histocompatibility complex.

The wm7 haplotype of the major histocompatibility complex (MHC), derived from the Japanese wild mouse Mus musculus molossinus, enhances recombination specific to female meiosis in the K/A beta interval of the MHC. We have mapped crossover points of fifteen independent recombinants from genetic crosses of the wm7 and laboratory haplotypes. Most of them were confined to a short segment of approximately 1 kilobase (kb) of DNA between the A beta 3 and A beta 2 genes, indicating the presence of a female-specific recombinational hotspot. Its location overlaps with a sex-independent hotspot previously identified in the Mus musculus castaneus CAS3 haplotype. We have cloned and sequenced DNA fragments surrounding the hotspot from the wm7 haplotype and the corresponding regions from the hotspot-negative B10.A and C57BL/10 strains. There is no significant difference between the sequences of these three strains, or between these and the published sequences of the CAS3 and C57BL/6 strains. However, a comparison of this A beta 3/A beta 2 hotspot with a previously characterized hotspot in the E beta gene revealed that they have a very similar molecular organization. Each hotspot consists of two elements, the consensus sequence of the mouse middle repetitive MT family and the tetrameric repeated sequences, which are separated by 1 kb of DNA.

Animals↗