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Biomedical subjects

N Kashiwagi

Publications and source records attributed to N Kashiwagi.

At least 19 recordsLinked to original sources
PubMed1992

Rapid DNA typing utilizing immobilized oligonucleotide probe and a nonradioactive detection system. Application to HLA-DR typing of the Japanese population.

We established a rapid and simple method of HLA-DR genotyping, and applied it for analysis of the Japanese population. Our method includes rapid preparation of DNA samples from buccal mucosa, incorporation of biotin-dATP into DRB genes during amplification by the polymerase chain reaction, hybridization with sequence-specific oligonucleotide (SSO) probes immobilized on nylon membranes via poly (dT) tails, and detection of the hybridization signal as chemiluminescence. We carried out DR typing of 30 Japanese donors using 20 different immobilized SSO probes, and obtained unambiguous typing signals showing perfect correlation with their serologic DR types. The genotyping also enabled us to identify several DR types unique to the Japanese population, such as DRw12b (DRB1*1202), DRw14c (DRB1*1405), and serology blank type, DR'JX6' (DRB1*1403). The method presented here would be suitable for routine DR typing in tissue-typing laboratories.

Base Sequence↗
PubMed1992

Effect of oligomers of ethylene glycol on thermotropic phase transition of dipalmitoylphosphatidylcholine multilamellar vesicles.

The effect of oligomers of ethylene glycol (EG) on thermotropic phase transitions of dipalmitoylglycerophosphatidylcholine multilamellar vesicles (DPPC-MLV) were investigated. Diethylene glycol (di-EG) had a biphasic effect on transition temperature, reducing pre-transition temperature (Tp) at low concentrations but increasing main transition temperature (Tm) and extinguishing pre-transition at high concentration. Results of the X-ray diffraction method and the excimer method indicated that di-EG induced interdigitated gel phase (L beta 1 phase) in the DPPC membranes at high concentration. Phase diagram of temperature-di-EG concentration for DPPC-MLV was determined by use of X-ray diffraction and differential scanning calorimetry, which was similar to that of temperature-EG concentration. The minimum concentration of di-EG where L beta 1 phase was induced was 42%(w/v), which was larger than that of EG (30%(w/v)). On the other hand, in the presence of triethylene glycol (tri-EG), Tm and Tp increased with an increased in tri-EG concentration, as well as poly(ethylene glycol). These differences, between the effects of di-EG and those of tri-EG, might be due to the differences of their sizes.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1992

Linkage between HLA-DRB1 and -DRB3 types in the Japanese population analyzed by oligonucleotide genotyping.

We analyzed linkage between HLA-DRB1 and -DRB3 types in 219 Japanese donors by oligonucleotide genotyping. In the Japanese population, DRB1*1201 was linked with DRB3*0101 in all donors analyzed; in contrast, most Caucasian DRB1*1201 is known to be linked with DRB3*02(01/02) (*0201 or *0202). However, most DRB1*1202 was linked with DRB3*0301. Thus, the two DRw12-related DRB1 types are linked with DRB3 types distinct from each other. All the three DRw14-related DRB1 types, DRB1*1401, DRB1*1402, and DRB1*1405, were linked with DRB3*02(01/02) in the Japanese population, contrasting with the known linkage between DRB1*1402 and DRB3*0101 in other ethnic populations. The serologically "blank" DR type, DRB1*1403, was linked with DRB3*0101. Other DRB1 types, DRB1*0301, DRB1*11(01/04) (*1101 or *1104), and DRB1*13(01/02) (*1301 or *1302) in the Japanese population were linked mostly with the same DRB3 types, like those known in other ethnic populations.

Alleles↗
PubMed1992

Phase transitions of phospholipid vesicles under osmotic stress and in the presence of ethylene glycol.

The effects of poly(ethylene glycol) (PEG) on the phase transition of phospholipid multilamellar vesicles (MLVs) were investigated by using differential scanning calorimetry (DSC). Main transition temperature (Tm) and the pre-transition temperature (Tp) of neutral phospholipid-, DMPC-1, DPPC- and DSPC-MLVs increased with an increase in PEG concentration. The subtransition temperature of DPPC-MLV also increased with an increase in PEG concentration. These results could be qualitatively explained by enhancement of the lateral packing on the basis of the osmoelastic coupling theory. The pretransition temperature increased faster than the main transition temperature did with an increase in PEG concentration. The increment of Tm depended on the hydrocarbon chain length, the shorter the hydrocarbon chain length was, the larger the increment was. The transition width in the DSC peak was broadened with an increase in PEG concentration. These three above-mentioned effects are the main differences between the effects of the osmotic stress on the phase transition of MLVs and those of hydrostatic pressure. On the other hand, ethylene glycol (EG), which is the monomer of PEG, had a biphasic effect on transition temperature of DPPC-, DSPC-, and DMPC-MLV, reducing Tm and Tp at low concentrations, but increasing Tm and extinguishing pretransition at high concentrations. This is explained by the induction of an interdigitated gel phase at high concentrations of EG, which indicates that EG can easily penetrate into the head group region of the lipid, in contrast with PEG 6K, because EG is small. Temperature-EG concentration phase diagrams for the various PC-MLVs were determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Calorimetry, Differential Scanning↗
PubMed1992

Analysis of HLA-DR types of unexplained recurrent spontaneous aborters in the Japanese population by oligonucleotide-DNA typing.

To examine whether unexplained recurrent spontaneous abortion (URSA), defined as 2 or more consecutive spontaneous abortions, is correlated with a particular DR type in the Japanese population, we determined the HLA-DR types of 82 primary aborters and 21 secondary aborters by DNA typing utilizing the polymerase chain reaction (PCR) and hybridization with sequence-specific oligonucleotides (SSOs). The DR gene frequencies of the patient group were compared with those of a normal group at three different levels of DR-definition (27, 13 and 11 DR types). At none of the three levels of comparison was any particular DR type with a frequency differing significantly between the patient and normal groups detected in Japanese URSA patients. Furthermore, we examined whether URSA was correlated with the degree of compatibility of HLA-DR antigen within patients and their husbands. Comparison of the DR compatibility between patients and normal couples was made in two different ways, i.e., comparison of the numbers of couples with mismatches and comparison of the average number of mismatches. For either of these two comparisons, we observed no difference in DR compatibility between patients and normal couples. Our results suggest that URSA is not correlated with any particular DR type and that the condition cannot be explained simply by DR compatibility between husband and wife.

Abortion, Habitual↗
PubMed1992

[Effect of the tumor cell associated glycoconjugate (TCA) derived Kato III, human gastric cancer cells on autologous mixed lymphocyte reaction in patients with rheumatoid arthritis].

We have been developing a new treatment for patients with rheumatoid arthritis (RA) by using intradermal injection of carbohydrate molecule complex. Among them, tumor cell associated glycoconjugate (TCA), the membrane structure of Kato III is one of the effective molecules. We studied the immunomodulatory effect of TCA on the autologous mixed lymphocyte reaction (AMLR) using PWM-mitogen induced lymphoblasts as stimulator cells and peripheral blood mononuclear cells (PBMC) as responder cells. In the kinetic study of the AMLR, its maximum proliferation was observed on days five through seven and responding CD4 cells highly expressed HLA-DR antigen. Studied AMLR in 10 patients with RA, proliferative responses of AMLR in these patients were divided into two types, high and low AMLR types. In vitro examination of TCA on AMLR showed that TCA at a concentration of 250 ng/ml significantly suppressed the AMLR response (p less than 0.01, paired T-test) and this phenomenon was found more frequently in high AMLR type patients than in low AMLR type patients. The suppressive effect of TCA on AMLR had a tendency to correlate with the efficacy of TCA therapy in patients studied. These results suggest that TCA may play a role in regulating the function of autoreactive lymphocytes of patients with RA.

Aged↗
PubMed1991

HLA-DR gene frequencies in the Japanese population obtained by oligonucleotide genotyping.

We determined HLA-DRB types of 375 randomly chosen healthy Japanese donors using a set of 29 different sequence-specific oligonucleotide (SSO) probes directed against various DRB alleles. Except for a few cases, these SSOs enabled us to identify 33 different DRB types including those detectable only by SSO genotyping. Gene frequencies were calculated for each of the DRB types identified. The "blank" frequency calculated by our SSO typing was essentially zero, in contrast to the considerably high "blank" frequencies reported at serological HLA-DR or cellular HLA-D workshops. This indicates that almost all of the DRB types in the Japanese population are positively detectable by our SSO typing. By comparing the gene frequencies for each of the DR types obtained by our SSO typing with those obtained by immunological typing at workshops, significant differences were observed for several of the DR types.

Alleles↗
PubMed1991

Association of HLA-DQw4 with IgA nephropathy in the Japanese population.

We have studied HLA-A, B, DR and DQ phenotypes in 50 Japanese patients with IgA nephropathy. The antigen frequency of HLA-DQw4, which is known to be associated with DR4/Dw15 specificity, was increased in the patient group as well as in those of B35 and DR4. The increase of DQw4 (36.0%) was significantly different from that of national controls (corrected p less than 0.004).

Adult↗
PubMed1991

[Two-color flow cytometric analysis on human peripheral blood T-lymphocytes using monoclonal antibody BM-1 directed to Le(Y) determinant structure].

We developed a new assay method for the evaluation of Le(Y) antigen expression on human peripheral T-lymphocytes using the monoclonal antibodies BM-1, CD4 and CD8 by two-color flow cytometry. Le(Y) antigen expressed on human peripheral T-lymphocytes was stained with fluorescein isothiocyanate (FITC)-labelled BM-1 (anti Le(Y) monoclonal antibody). Le(Y) positive cells were simultaneously stained with phycoerythrin (PE)-labelled CD4 or CD8, then analyzed by flow-cytometer. Coefficients of variations in this double staining assays were 4.2% for BM-1 in CD4 and 5.3% for BM-1 in CD8, respectively. In 124 healthy volunteers 0.2-13.1% of CD4 and 2.5-12.5% of CD8 positive cells were BM-1 positive. Lymphocytes from 200 patients with acute or chronic viral hepatitis showed marked increase in BM-1 expression of CD8 positive cells during the acute phase and exacerbation of the disease. Moreover, BM-1 expression of CD4 cells was positively related with the course of the chronic hepatitis and the prognosis of each patients. Therefore, this new assay using BM-1 and CD4, CD8 monoclonal antibodies would reflect progression of viral hepatitis and its related immunological condition.

Adult↗
PubMed1990

Sequence analysis and HLA-DR genotyping of a novel HLA-DRw14 allele.

Analysis of a Japanese population by oligonucleotide genotyping revealed that one Japanese HLA-DRw14 allele had a DRB1 genotype different from that of the known HLA-DRw14-related alleles, DRB1*1401 (DRw14-Dw9) and DRB1*1402 (DRw14-Dw16). The second exon of the DRB1 gene of the novel DRw14 allele (designated DRB1-14c) was amplified enzymatically and sequenced after cloning into a plasmid vector. The amino acid sequence of the first domain in the DR beta 1 chain encoded in the DRB1-14c allele was more similar to that of the DRB1*1401 allele (three amino acid substitutions) than to that of the DRB1*1402 allele (six amino acid substitutions). No polymorphic amino acid residue that could explain the common serologic HLA-DRw14 specificity was identified among the sequences of the three DRw14-related alleles. Sequence-specific oligonucleotides (SSOs) were synthesized on the basis of the DRB1-14c nucleotide sequence and used for genotyping of the Japanese population. These SSOs served as useful probes for identifying the DRB1-14c allele in a wide range of donors.

Alleles↗
PubMed1990

Sequence analysis and oligonucleotide genotyping of HLA-DR"JX6", a DR"blank" haplotype found in the Japanese population.

We analyzed one of the HLA-DR"blank" haplotypes found in the Japanese population using serologic studies, sequence determination, and genotyping with sequence-specific oligonucleotide (SSO) probes. The DR"blank" haplotype, designated DR"JX6", segregated in a family in association with the DRw52 and the DQw7 specificities. The cDNA and genomic DNA of the DRB1 gene originating from the DR"JX6" haplotype were amplified enzymatically and sequenced after cloning into a plasmid vector. The amino acid sequence of the first domain in the DR beta 1 chain of the DR"JX6" haplotype was different from those of other DR haplotypes sequenced so far, but in the first hypervariable region, the sequence was identical to those of the DRw11, DRw13, DRw14, and DRw17 haplotypes. SSO probes were synthesized on the basis of the DR"JX6" haplotype sequence as well as known sequences of the DRB1, DRB3, and DRB4 genes of other DR haplotypes. These SSO probes were used for the genotyping of Japanese donors whose DRB genes were amplified enzymatically and found to show a hybridization profile that was consistent with the results of serologic studies on the DR"JX6" haplotype.

Amino Acid Sequence↗
PubMed1990

The role of HLA-DR4 in the long-term prognosis of IgA nephropathy.

The study was performed to clarify the relationship between the long-term prognosis of IgA nephropathy and the HLA-DR4 antigen. From the 130 patients typed for HLA antigens, stable (n = 42) and progressive (n = 45) patient groups were selected. DR4 frequency was not different in the two groups (stable, 66.7 vs. progressive, 53.3%). However, the frequencies of HLA-DR4 and B35 in the 130 patients were significantly higher than those in the national control (DR4; 60.0 vs. 41.6%; B35:30.0 vs. 15.5%). We concluded that DR4 played no role in the long-term prognosis of IgA nephropathy, but that B35 and DR4 were associated with the disease in the Japanese population.

Adult↗
PubMed1990

Empirical Bayes methods for smoothing data and for simultaneous estimation of many parameters.

A recent successful development is found in a series of innovative, new statistical methods for smoothing data that are based on the empirical Bayes method. This paper emphasizes their practical usefulness in medical sciences and their theoretically close relationship with the problem of simultaneous estimation of parameters, depending on strata. The paper also presents two examples of analyzing epidemiological data obtained in Japan using the smoothing methods to illustrate their favorable performance.

Bayes Theorem↗
PubMed1989

Calcification of spinal cord tumors: report of two cases.

Two cases of calcification of spinal cord tumors were detected by computed tomography and magnetic resonance imaging. The first; a 27-year-old male, with a very rare astrocytoma accompanied by calcification of the thoracic spinal cord, and the second; a 62-year-old female, with a rare calcified neurilemmoma in the upper cervical extradural space. The purpose of this paper is to draw attention to the fact that some spinal cord tumors occasionally contain areas of calcification, and review the literature on this subject.

Adult↗
PubMed1989

Activation of human T cells by toxic shock syndrome toxin-1: the toxin-binding structures expressed on human lymphoid cells acting as accessory cells are HLA class II molecules.

Toxic shock syndrome toxin-1 (TSST-1)-binding assay using 125I-labeled TSST-1 showed the presence of specific TSST-1 binding in a B cell fraction of human peripheral blood mononuclear cells and L cells transfected with DR2 genes or DR4 genes but not in a T cell fraction and control L cells. Fixation with paraformaldehyde, an inhibitor of antigen processing, did not remove TSST-1-binding activity of the transfectants. Binding of 125I-labeled TSST-1 to the transfectants was reduced by an anti-DR monoclonal antibody. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of a single band with TSST-1-binding activity and the same migration pattern as DR heterodimers. TSST-1-induced T cell responses, proliferation and interleukin 2 (IL2) production were observed in the presence of the transfectants but not in the presence of control L cells, while concanavalin A-induced IL2 production was observed in the presence of either the transfectants or control L cells. Presence of an anti-DR monoclonal antibody inhibited the TSST-1-induced responses. Paraformaldehyde-fixed Daudi cells were effective in supporting TSST-1-induced IL2 production by T cells. These results indicate that HLA class II molecules directly bind intact TSST-1 and perform an essential role as the TSST-1-binding structures on accessory cells in T cell activation by the toxin.

Antigen-Presenting Cells↗
PubMed1989

Two distinct subtypes of the HLA-DRw12 haplotypes in the Japanese population detected by nucleotide sequence analysis and oligonucleotide genotyping.

We determined the DNA sequence of the enzymatically amplified second exon of the DRB1 gene of the Drw12 haplotypes derived from three Japanese donors and found two distinct subtypes of the DRw12 haplotype. The two subtypes, designated DRw12a and DRw12b, had single-base substitutions that predicted one amino acid change at residue number 67. The sequence of the DRw12a and DRw12b subtypes differed from those of the other DR haplotypes, but in the first hypervariable region of the DRB1 gene the sequences were identical to those of the DRw8(Dw8.1) and DRw8(Dw8.3) haplotypes. The DRw12a and DRw12b subtypes were detected in a wide range of Japanese donors by genotyping with sequence-specific oligonucleotide probes synthesized according to the DNA sequences of the two subtypes. Results of this study demonstrated that the DRw12 haplotypes in the Japanese population are genetically diverse, as many other DR haplotypes are.

Asian People↗
PubMed1989

Follow-up study of reconstructed auricle in microtia: comparison of the results of the rib cartilage framework and the silicone rubber framework methods.

Plastic surgery for microtia had achieved fairly consistent good results since TANZER (Plast. Reconstr. Surg. 23: 1-15, 1959) and recently the modified methods have become popular. The authors did plastic surgery of auricles with the rib cartilage framework method from 1968 until 1986, and with the silicone rubber framework method from 1975 until 1986, and observed each postoperative course for 2 to 10 years. The operative results and the merits and the demerits of each method are reported here. The subjects were 49 ears for the rib cartilage framework method (17 of the former period, 1968-1977, and 32 of the latter, 1978-1986), and 20 ears for the silicone rubber framework method. The operation was performed in 3 stages according to the modified Tanzer's method. The results of operations were subjectively assessed as "satisfied," "fairly satisfied," "a little unsatisfied," and "unsatisfied." The results were as follows: 1) in the rib cartilage framework method, there were 21 satisfied cases (43%), 17 fairly satisfied cases (35%), and 5 unsatisfied cases (10%); 2) there were 8 satisfied cases (40%), 5 fairly satisfied cases (25%), and 6 unsatisfied cases (30%) in the silicone rubber framework method. From the aspect of postoperative management, the rib cartilage framework method is now better but the authors expect the silicone rubber framework method will be improved and used more extensively in the future.

Cartilage↗