Search PubMed⌕ Search

Biomedical subjects

N Ishiguro

Publications and source records attributed to N Ishiguro.

At least 127 records · Page 7Linked to original sources
PubMed1994

[Effect of recombinant human erythropoietin on cytosolic free calcium concentration in platelets].

Intracellular free calcium concentration ([Ca2+]i) was examined in the platelets of 15 control subjects (NT), 6 predialysis patients with chronic renal failure (CRF), 17 patients on hemodialysis (HD), 20 patients on continuous ambulatory peritoneal dialysis (CAPD), 10 normotensive persons with genetic hypertension (GHT) and 8 essential hypertensive patients (EHT). Levels of [Ca2+] i in the platelets were measured by the fluorescent calcium indicator Fura-2. Resting [Ca2+] i in CRF and HD patients was higher than the value in NT and that in CAPD patients was similar to NT. rHuEPO significantly increased the level of [Ca2+] i in CRF and HD patients compared to those in NT. Under resting and EPO-stimulated conditions, the levels of [Ca2+] i in GHT and EHT were higher than those in NT. rHuEPO increased the levels of [Ca2+] i in the absence of extracellular calcium in NT, GHT and EHT. In addition, EPO-stimulated calcium influx in GHT and EHT was greater than that in NT. Thus, it appears that the mechanism of rHuEPO-induced hypertension may be mainly due to elevation of [Ca2+] i. EPO may contribute to the development of genetic hypertension.

Adult↗
PubMed1993

The effects of nitric oxide on chondrocytes and lymphocytes.

ConcanavalinA (ConA)-activated lymphocytes markedly induced the production of nitric oxide from chondrocytes. The nitric oxide significantly inhibited the proliferation of both the chondrocytes themselves and the lymphocytes. When culture supernatant from ConA-activated lymphocytes was added to culture of chondrocytes, a large amount of nitric oxide was produced. NG-monomethyl-L-arginine (MMA) significantly eliminated both the production of nitric oxide and the inhibition of chondrocyte and lymphocyte proliferation. Furthermore, when MMA was added to the mixed culture of chondrocytes and lymphocytes with ConA, their proliferation was markedly enhanced compared with individual summation. These results indicate that chondrocytes produce not only nitric oxide but also a lymphocyte stimulating factor, the effects of which are, however, usually masked by the nitric oxide.

Animals↗
PubMed1993

Hepatitis C virus antibody in patients with primary liver cancer (hepatocellular carcinoma, cholangiocarcinoma, and combined hepatocellular-cholangiocarcinoma) in Japan.

BACKGROUND: In hepatocellular carcinoma (HCC), a high prevalence of hepatitis C virus antibody (anti-HCV) has been reported, indicating that it may be an important etiologic factor in the pathogenesis of HCC. In this study, the authors investigated the prevalence of anti-HCV in HCC patients, as well as the same prevalence in patients with cholangiocarcinoma (CC) and combined hepatocellular-cholangiocarcinoma (combined HCC-CC), to study the clinicopathologic features of anti-HCV-positive cases. METHODS: The authors examined 141 patients with primary liver cancer who were pathologically diagnosed as having HCC (121 cases), CC (13 cases), or combined HCC-CC (7 cases). Hepatitis B surface antigen (HBsAg) and anti-HCV were measured in these patients. RESULTS: Of 121 HCC cases, 85 (70.3%) were found to be anti-HCV positive, 16 (13.2%) were HBsAg positive, and 5 (4.1%) were both anti-HCV and HBsAg positive. In 13 cases with CC and in 7 with combined HCC-CC examined, 4 (30.8%) and 5 (71.4%), respectively, were anti-HCV positive. CONCLUSIONS: The anti-HCV-positive rate was high in combined HCC-CC as well as in HCC. These three types of primary liver cancer, which were anti-HCV positive, shared two common features: male dominance and high incidences of complication with liver cirrhosis.

Adenoma, Bile Duct↗
PubMed1993

Thy-1 antigen dendritic cells and rejection of composite tissue limb allografts in rats.

Dendritic-shaped cells (Thy-1+DC) characterized by the surface phenotype of Thy-1+, asialo GM1+, Ia- are reported to exist exclusively in mice. However, Thy-1+ dendritic cells were observed in the skin of normal athymic nude F344, euthymic F344, and WKAH rats. Their phenotypic markers were Thy-1+, asialo GM1+, Ia-, W3/25 (helper/inducer)-, OX8 (cytotoxic/suppressor)-, W3/13 (pan T lymphocytes)-, OX39 (IL-2)-, and OX41 (macrophages)-. These phenotypic markers were analogous to those of mice. The density of Thy-1+DC in the skin of normal nude F344 rats was approximately twice as much as that of F344 and WKAH rats. When WKAH rats were used as donors with nude F344 rats as recipients (this combination being a major mismatch with regard to a MHC, rejection-like changes such as edema and erythema were observed 1 week after the grafting. An immunohistochemical examination demonstrated that the density of Thy-1+DC had increased 3-fold within the donor skin at 1 week after transplantation, although almost no W3/25 positive cells, OX8 positive cells, or other inflammatory cells were observed. Within 2 weeks of transplantation the donor skin ceased rejection-like changes and the density of Thy-1+DC was reduced to preoperation levels. When WKAH rats were used as donors with F344 rats as recipients, severe rejection was observed, and many T cells with W3/25 or OX8 antigens and granulocytes had infiltrated into the skin at the donor sites. Thy-1+DC could not be found in the donor skin. These findings suggest that a correlation exists between Thy-1+DC and rejection-like changes in the donor skin when nude rats are used as recipients.

Animals↗
PubMed1993

Nuclear DNA content and distribution of Ki-67 positive cells in nodular fasciitis.

Nodular fasciitis (NF) is regarded as a disease of reactive growth of fibroblasts, although it frequently shows clinically rapid growth and sometimes has to be histologically discriminated from fibrosarcoma. In order to confirm the position of NF as a benign tumor, we studied 5 cases of NF by a quantitative analysis of the nuclear DNA content using flow cytometry in paraffin-embedded specimens. In 3 of the 5 cases, an immunohistochemical study using Ki-67 monoclonal antibody was also conducted in frozen sections. In the analysis of nuclear DNA content, DNA histograms showed a diploid pattern in all cases, and G1, S and G2 + M periods were calculated as 96.7%, 2.5% and 0.8% (on the average), respectively. Although the labeling index of Ki-67 antibody (positive cells/tumor cells; %) was as scattered as 1.3-7.8 (5.6 on the average), the mean value was higher than that in already reported dermatofibroma and dermatofibrosarcoma protuberans and lower than that in malignant fibrous histiocytoma. These results endorse the hypothesis that NF is a reactive benign disease and reflect the biological behavior of this disease, which may frequently show rapid growth.

Adult↗
PubMed1993

Familial scrapie cases with shortened incubation periods.

Two familial scrapie cases successively occurred in 29-month-old and 30-month-old Corriedale dams and in three of their offspring as early as 10-19 months of age in a small flock. They showed ataxy but no pruritus. Histopathological and immunochemical examinations of those sheep revealed vacuolation of nerve cells in brain tissue and presence of PrPsc, a component of scrapie-associated fibrils, in brain, spleen and lymph node tissues. We discuss about shortened incubation periods and lacking pruritus in the present scrapie cases.

Animals↗
PubMed1993

Specific expression of cellular oncogenes c-myc and c-myb in T-cell lines established from three types of bovine lymphosarcomas.

Expression of cellular oncogenes in 3 lymphoid cell lines, BTL-PC3 (BoCD2-, BoCD4-, BoCD8-, BoWC1+), BLS1 (BoCD2+, BoCD4-, BoCD8-, BoWC1+) and BLT2 (BoCD2-, BoCD4-, BoCD8-, BoWC1-), which have been established from calf, skin, and thymic types of lymphosarcomas, respectively, were analyzed by DNA-RNA (northern blot) hybridization. To determine specific expression of oncogenes involved in malignant transformation of the lymphoid cells, cellular RNA was isolated from bovine tumor cell lines, BTL-PC3, BLS1, and BLT2, and from Madin Darby bovine kidney cells used as a control for bovine cell lines. The RNA was hybridized against 5 viral oncogene probes (v-jun, v-myc, v-erbB, v-erbA and v-fes), 6 human cellular oncogene probes (N-ras, c-Blym-1 c-erbB-2, c-fos, c-myb and c-abl), human p53 tumor suppressor gene, and bovine LDH-A gene probes. Line BTL-PC3 expressed 2.4-kilobase (kb) c-myc and 4.0- and 3.6-kb c-myb transcripts, and line BLT2 expressed a 3.8-kb c-myb transcript, but line BLS1 expressed no message for the oncogenes tested. Specific transcripts of p53 were found in BTL-PC3 and BLT2 lines, but not in BLS1. Madin Darby bovine kidney cell line expressed multiple cellular oncogenes, c-jun, c-myc, and c-fos, and p53 genes. Southern blot hybridization did not reveal abnormal DNA rearrangements associated with the expressed oncogenes (c-myc and c-myb) in the 3 bovine tumor lines. (ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Terminal phalangeal osteosclerosis in rheumatoid arthritis].

OBJECTIVE: Osteosclerosis of the terminal phalanges of the hand has been reported in the collagen diseases including rheumatoid arthritis (RA). The current study was made to clarify the significance of terminal phalangeal osteosclerosis in RA. METHODS: Hand x-ray films of 108 patients (male 13, female 95) with RA for more than 10 years were assessed by Halim's grading. Grade 2, (Distance between both cortices is < 1 mm but there is still an intermediate space discernible), and grade 3, (Complete fusion of both cortices, but the base of the terminal phalanx is open), were classified as the positive group. Grades 0 and 1 were classified as the negative group. Both groups were compared and sigma GS/D values was measured at terminal phalanges, middle phalanges and metacarpuses of right middle fingers using digital image processing method. sigma GS/D index was calculated as being equal to the ratio of sigma GS/D value of the terminal or middle phalanx to sigma GS/D value of the metacarpus. RESULTS: Thirty cases (28%) were positive (male 1, female 29). Osteosclerosis of terminal phalanges usually appeared in more than two digits bilaterally. It was located as follows; thumb-1 case, index-13 cases, middle-24 cases, ring-51 cases, little-58 cases. Obliteration of the medullary space of middle phalanges was seen in 5 cases. No difference was observed between the positive and negative groups about sex, age, the mean value of C-reactive protein, the incidence of Steinblocker's class classification and the rate of seropositive patients. Osteosclerosis of terminal phalanges was observed at first consultation in 93% of positive cases. Osteosclerosis is expected to appear in the early phase of RA and to last for more than 10 years. sigma GS/D index of the positive group (1.03 +/- 0.24, mean +/- SD) was greater than that of the negative group (0.63 +/- 0.25) (p < 0.05).

Adult↗
PubMed1993

Transforming growth factor-beta 1 enhances the generation of allospecific cytotoxic T lymphocytes.

We investigated the effects of transforming growth factor-beta 1 (TGF-beta 1) on the proliferation and generation of murine T lymphocytes in vitro. TGF-beta 1 suppressed T- and B-lymphocyte proliferation, mixed lymphocyte reaction (MLR), and the generation of natural killer (NK) cells and lymphokine-activated killer (LAK) cells. On the other hand, TGF-beta 1 significantly enhanced the generation of allospecific cytotoxic T lymphocytes (CTL) at low concentrations (0.01-1 ng/ml) in a dose-dependent manner and restored it to the control level at higher concentrations (10-40 ng/ml). Allospecific CTL generation by TGF-beta 1 was maximally enhanced when added at the beginning of culture. Less enhancement occurred when the addition was delayed. Anti-TGF-beta 1 antibody completely abolished the enhancing effects of TGF-beta 1. Furthermore, platelet-derived TGF-beta (pTGF-beta) as well as recombinant TGF-beta 1 similarly enhanced the generation of allospecific CTL. These data demonstrate that TGF-beta has not only immunosuppressive effects but also immuno-enhancing effects in vitro.

Animals↗
PubMed1992

A rat model of human T lymphocyte virus type I (HTLV-I) infection. 1. Humoral antibody response, provirus integration, and HTLV-I-associated myelopathy/tropical spastic paraparesis-like myelopathy in seronegative HTLV-I carrier rats.

Human T lymphocyte virus type I (HTLV-I) can be transmitted into several inbred strains of newborn and adult rats by inoculating newly established HTLV-I-immortalized rat T cell lines or the human T cell line MT-2. The transmission efficiency exceeds 80%, regardless of strain differences or the age at transmission. The production of anti-HTLV-I antibodies significantly differs among the strains and depends on the age at the time of transmission. Rats neonatally inoculated with HTLV-I-positive rat or human cells generally become seronegative HTLV-I carriers throughout their lives, whereas adult rats inoculated with HTLV-I-positive cells at 16 wk of age become seropositive HTLV-I carriers. The HTLV-I provirus genome is present in almost all organs, regardless of whether the carriers are seronegative or seropositive. According to antibody titers to HTLV-I, there are three groups of inbred rat strains: ACI, F344, and SDJ (high responders); WKA, BUF, and LEJ (intermediate responders); and LEW (low responder). Three of three 16-mo-old seronegative HTLV-I carrier rats of the WKA strain developed spastic paraparesis of the hind legs. Neuropathological examinations revealed that the lesions were confined primarily to the lateral and anterior funiculi of the spinal cord. Both myelin and axons were extensively damaged in a symmetrical fashion, and infiltration with massive foamy macrophages was evident. The most severe lesions were at levels of the thoracic cord and continued from the cervical to the lumbar area. These histopathological features as well as clinical symptoms largely parallel findings in humans with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). These HTLV-I carrier rats, in particular the WKA rats described above, can serve as a useful animal model for investigating virus-host interactions in the etiopathogenesis of HTLV-I-related immunological diseases, particularly HAM/TSP.

Aging↗
PubMed1992

Cloning and nucleotide sequence of the gene (citC) encoding a citrate carrier from several Salmonella serovars.

The nucleotide sequence of the citC coding for the citrate carrier in several Salmonella serovars has been determined, and the amino acid sequence of the carrier protein was deduced. The predicted citrate carrier from Salmonella pullorum and Salmonella enteritidis consists of 446 amino acids with a molecular weight of 47,621, whereas that from Salmonella dublin is the same 446 amino acids with the slightly different molecular weight of 47,591, because 1 amino acid residue was substituted. The predicted proteins are highly hydrophobic (69% nonpolar amino acids). The hydropathy profile suggests that the proteins are composed of 11-12 hydrophobic membrane-spanning segments with two hydrophilic cores in the middle of the protein sequence. No homology in the nucleotide and amino acid sequences was found in the molecular structures of citA, citP, and tctI genes. The citC-coding citrate transport activity is Na(+)-dependent and specific for citrate only. The transcript from the citC gene was not detected in the total RNA from several Salmonella serovars except S. dublin in Northern blot analysis, although the promoter of the citC genes appeared to be functional in Escherichia coli and Salmonella typhimurium strains using the lacZ fusion assay. These results suggested that the citC gene-coding citrate carrier is probably a TctIII system such as that identified previously in S. typhimurium.

Amino Acid Sequence↗
PubMed1992

Molecular cloning and sequence analysis of bovine T-cell receptor gamma and delta chain genes.

Nine bovine T-cell receptor (Tcr) gamma chain (Tcrg) and three Tcr delta chain (Tcrd) cDNA clones were isolated from the cDNA libraries constructed from peripheral blood lymphocytes and thymocytes. Of nine Tcrg cDNA clones, only four were rearranged and contained specific V, J, and C gene segments, but the remaining five contained specific J and C or only C gene segments without the V gene segment. Three kinds of Tcrg-C, which were highly related at the nucleotide and amino acid levels, were found and designated as Tcrg-C1, Tcrg-C2, and Tcrg-C3. Compared with human and mouse Tcrg-C, bovine Tcrg-C sequences are much longer, with about 27-55 amino acids corresponding to the hinge and connector regions, where the characteristic repetitive 5-amino acid motif (TTEPP or TTKPP) exists in sheep Tcrg-C as previously reported. From three Tcrd cDNA clones, two Tcrd-V and three Tcrd-J segments were isolated. The nucleotide and deduced amino acid sequences of bovine Tcrd-C, especially the transmembrane and cytoplasmic domains, are well conserved among species. As in bovine Tcrg-C, diversity of amino acid residues in the Tcrd-C region is concentrated in the hinge regions. Southern blot analysis showed that there are at least three Tcrg-C genes and one Tcrd-C gene in the bovine genome. The analysis also revealed the presence of Tcrg-C- and Tcrd-C-associated restriction fragment length polymorphisms among bovine breeds.

Amino Acid Sequence↗
PubMed1992

A specific RFLP type associated with the occurrence of sheep scrapie in Japan.

We have investigated restriction fragment length polymorphism (RFLP) on the PrP gene and the frequencies of RFLP patterns in 35 healthy Suffolk sheep randomly collected. According to the combinations of PrP encoding DNA fragments generated by restriction enzymes Eco RI and Hind III, the RFLP patterns were classified into six types and designated as types I to VI. The frequencies of these types were as follows: I, 8.6%; II, 11.4%; III, 17.6%; IV, 11.4%; V, 28.6%; and VI, 22.9%. In 10 sheep diagnosed as having natural scrapie, RFLP types, I, III, IV, and V were determined. To examine the correlation between the RFLP type and the occurrence of scrapie, the frequencies of RFLP types in sheep infected with natural scrapie were compared with those in healthy sheep. It was found that the frequency of type I in the sheep with natural scrapie was 70%, about eight times higher than that in randomly collected healthy sheep. In the 13 experimentally infected sheep that had been used for other purposes, however, no relationship between the RFLP type and onset of scrapie was found.

Animals↗
PubMed1992

Comparative sequence analysis and expression of bovine PrP gene in mouse L-929 cells.

A cDNA clone encoding bovine scrapie-associated fibril protein, PrP, from a bovine brain cDNA library and six amplified genomic DNA clones of bovine PrP were characterized. These clones possessed specific characteristics observed in other animal PrP genes. However, the bovine PrP was divided into two types by the number of repeats. One possessed four octapeptide repetitive sequences, like other animal PrP genes, and consisted of 256 amino acids; the other had five such repetitive sequences and 264 amino acids. The amino acid sequence of the former bovine PrP agreed with that of sheep PrP up to the 165th amino acid from the N-terminus. Bovine PrP cDNA introduced into mouse L-929 cells were stably expressed. The expression level of recombinant bovine PrP in the cells judged by immunofluorescence was higher than that of authentic mouse PrP. The recombinant PrP comigrated with authentic bovine PrP in SDS-polyacrylamide gel electrophoresis, suggesting that the recombinant product was fully glycosylated in L-929 cells. Distinct bundles of the intermediate filaments were frequently seen at the perinuclear region of the cells.

Amino Acid Sequence↗
PubMed1992

Acute effects of angiotensin-converting enzyme inhibitor on erythrocyte sodium ion transport in essential hypertension.

The acute effects of angiotensin-converting enzyme inhibitor, captopril, on sodium ion transport systems were investigated in essential hypertensive and normotensive subjects. The passive sodium efflux through the erythrocyte membrane was significantly higher and erythrocyte sodium-potassium cotransport was lower in patients with essential hypertension when compared with normal subjects. However, sodium-potassium pump activity and sodium-lithium countertransport did not differ significantly between the hypertensive patients and the normal subjects. Immediately after captopril administration, erythrocyte passive sodium efflux and sodium-potassium cotransport returned to normal levels in the hypertensive subjects. Although the plasma renin activity and plasma aldosterone concentration were altered by captopril, they did not correlate with changes in any sodium transport system. These results suggest that the changes in sodium transport systems which occur immediately after captopril administration may contribute, at least in part, to its antihypertensive action.

Adult↗