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Biomedical subjects

K Tsuji

Publications and source records attributed to K Tsuji.

At least 415 records · Page 23Linked to original sources

[Evaluation of the combination of chemotherapy with etoposide, adriamycin and cisplatin (EAP) in advanced or recurrent gastric cancer].

EAP therapy was performed on 30 cases of advanced or recurrent gastric cancer between September 1987 and July 1991. The clinical responses of 15 trial patients were evaluated. The overall response rate was 40.0% (CR, one case; PR 5 cases). The results were thus not as favorable as that reported by Preusser et al. On the contrary, with such a poor response rate, this treatment did not lead to a prolonged life span (mean survival time; 5.6 months, median survival time; 4 months). Side effects, such as myelosuppression, appetite loss, nausea, vomiting, liver dysfunction, renal dysfunction, and alopecia, were also observed. Myelosuppression was a dose-limiting factor. The rhG-CSF proved in 4 cases to be a clinically useful tool against the neutropenia induced by this treatment. It may be concluded that EAP should be given to the following selected patients: (1) those whose condition is not so far advanced: (2) those who have not received many other forms of treatment; and (3) those in excellent general physical condition.

Adult↗

Natural killer (NK) cell stimulatory factor or IL-12 has differential effects on the proliferation of TCR-alpha beta+, TCR-gamma delta+ T lymphocytes, and NK cells.

We have analyzed the effects of NK cell stimulatory factor/IL-12, on proliferation of PBL and their subsets. IL-12 synergizes with lectins and phorbol diesters to induce proliferation of CD4+ and CD8+ peripheral blood T lymphocytes. In the case of phorbol-diester-induced proliferation, the effect of IL-12 is in part mediated by induced IL-2 production, as suggested by the observation that IL-12 enhances IL-2 production in these cultures and that anti-IL-2 antibodies inhibit proliferation. IL-12 synergizes also with anti-CD3 antibodies and with allogeneic stimulation in MLC in inducing T cell proliferation. IL-12 alone is mitogenic for preactivated T and NK lymphoblasts. This mitogenic effect is observed with similar doses of IL-12 on NK lymphoblasts as well as on CD4+ and CD8+ TCR-alpha beta+ and on TCR-gamma delta+ lymphoblasts. On TCR-alpha beta+ T lymphocytes the effect of IL-12 is always additive to that of IL-2 over a wide dose range. The same effect is observed on highly activated, actively proliferating NK cells. However, on NK and TCR-gamma delta+ lymphoblasts reverting to a resting state after stimulation and on a TCR-gamma delta+ acute leukemia-derived T cell line, IL-12 inhibits significantly the proliferation induced by moderate to high doses (10 to 100 U/ml) of IL-2. This inhibitory effect is, at least in part, indirect, and depends on IL-12-induced production of TNF. Neutralizing anti-TNF antibodies, but not anti-IFN-gamma and anti-transforming growth factor antibodies, restore by more than 70% the inhibition of proliferation induced by IL-12 in these cultures. However, TNF alone cannot mimic the inhibitory effect of IL-12 on the IL-2-induced proliferation of NK and TCR-gamma delta+ lymphoblasts, suggesting the involvement of additional mechanisms. The relevance of these findings for the biology of lymphocyte subsets mediating MHC nonrestricted cytotoxicity is discussed.

Flow Cytometry↗

Species and sex differences of aflatoxin B1-induced glutathione S-transferase placental form in single hepatocytes.

Species and sex differences of aflatoxin B1 (AFB1)-induced glutathione S-transferase placental form (GST-P) positive single hepatocytes have been investigated 48 h after an intraperitoneal injection of AFB1 to young male and female Fischer rats (2 mg AFB1/kg body wt) and male Syrian golden hamsters (6 mg AFB1/kg body wt). The presence of GST-P positive hepatocytes was examined by the immunohistochemical method. Male rats formed three times as many AFB1-induced GST-P positive hepatocytes as females. Pretreatment of both male and female rats with an inhibitor of GSH synthesis, buthionine sulfoximine (BSO) (4 mmol/kg body wt), 2 h and 4 h before AFB1 injection increased AFB1-induced GST-P positive hepatocytes by about 120% above the controls. Male hamsters formed several-fold less AFB1-induced GST-P positive hepatocytes than male rats. Pretreatment with BSO did not increase AFB1-induced GST-P positive hepatocytes in hamsters even though it produced an increase in hepatic necrosis. It appears that GSH and GSH S-transferases play an important role in modulating hepatic AFB1-DNA binding and AFB1-induced GST-P positive hepatocytes in rats and hamsters.

Aflatoxin B1↗

Capillary electrophoresis-electrospray mass spectrometry for the analysis of recombinant bovine and porcine somatotropins.

A Beckman P/ACE 2050 high-performance capillary electrophoresis (HPCE) instrument has been interfaced with a Vestec electrospray ionization (ESI) mass spectrometer for the analysis of recombinant proteins. Peak resolution is not compromised by coupling HPCE to an ESI mass spectrometer. Recombinant bovine and porcine somatotropins (rbSt and rpSt) were used as model proteins. The standard curve of the capillary zone electrophoresis (CZE) method with UV detection for the determination of rpSt is linear in the range of 7-300 fmol with theoretical plates of approximately 410,000 m-1. The relative standard deviation for the rpSt peak migration time is less than 1%. The multiply-charged ion clusters obtained in the CZE-ESI mass spectrum for a sample of rpSt ranged from mlz 1363.2 (the cluster with 16 charges) to 1982.5 (the cluster with 11 charges). The average molecular weights of 21,812.6 and 21,798.3 for a sample of rbSt and rpSt determined in this study were nearly identical to the theoretical values of 21,812.0 and 21,797.9, respectively. Detection limit of the CZE-ESI mass spectrometer is approximately 100 fmol. The CZE method separated mono- and dideamidated species and monoacetylated compounds while the ESI mass spectrometer detected an analogue and a truncated homologue of rpSt comigrating with the major peak. The presence of mono- and dioxidized homologues was also detected in the major peak of some rbSt and rpSt samples. These data clearly indicated that, individually, both CZE and ESI mass spectrometric methods could not detect all impurities. Coupling of the HPCE Instrument and the ESI mass spectrometer enhances analytical capabilities of both tools for rapid characterization of recombinant proteins.

Animals↗

Changes in cell surface antigen expressions during proliferation and differentiation of human erythroid progenitors.

Cell surface antigen expression during proliferation and differentiation of human erythroid progenitors was examined using a combination of sequential micromanipulations of paired daughter cells derived from erythroid burst-forming units (BFU-E) and immuno-staining with a panel of monoclonal antibodies. Single hematopoietic progenitors were identified in methylcellulose cultures containing human cord blood mononuclear cells and micromanipulated individually to secondary culture. Paired daughter cells, granddaughter cells, and subsequent generations, whose counterparts produced erythroid bursts, were stained with various cytochemical and immuno-alkaline phosphatase stainings. Most paired daughter cells of BFU-E immunostained positively with anti-platelet glycoprotein(GP) IIb, antiplatelet GPIIb/IIIa, anti-HLA-DR, and antitransferrin receptor antibodies. Acid phosphatase staining was also positive. Neither CD34 nor CD33 antigens were identified on the cells. CD36 and blood group A antigens were first identified on cells from aggregates containing 32 to 64 cells after 4 days of secondary culture and preceded the expression of glycophorin A and hemoglobin alpha. These results indicate that various cell surface antigens were sequentially expressed during the proliferation and differentiation of erythroid progenitors, and that our procedure may be useful for clarifying the morphologic and immunologic properties of hematopoietic stem cells.

Antibodies, Monoclonal↗

Enhancement of murine hematopoiesis by synergistic interactions between steel factor (ligand for c-kit), interleukin-11, and other early acting factors in culture.

Entry into the cell cycle of dormant hematopoietic progenitors appears to be regulated by multiple synergistic factors, including interleukin-6 (IL-6), granulocyte colony-stimulating factor (G-CSF), IL-11, and the ligand for c-kit, which is also known as steel factor (SF). We have tested the effects of these and other hematopoietic factors on the proliferation of partially enriched dormant murine progenitors in the presence and absence of serum. In serum-containing cultures, SF and IL-11 interacted to support the formation of multilineage colonies; the level of colony formation was comparable with the colony formation supported by other effective two-factor combinations. In serum-free cultures, colony formation supported by two factors was significantly less than that in serum-containing culture and the most effective two-factor combination in serum-free culture was SF plus IL-3. In serum-free cultures, three-factor combinations consisting of SF, IL-3, and one of IL-6, G-CSF, or IL-11 yielded colony formation that was comparable with that seen in serum-containing cultures. These studies indicate that IL-11 belongs to a group of early-acting hematopoietic synergistic factors that now includes IL-6, G-CSF, and IL-11. In contrast, SF is unique among the synergistic factors in that it interacts either with growth factors such as IL-3 or GM-CSF or with synergistic factors such as IL-6, IL-11, or G-CSF.

Animals↗

Basic fibroblast growth factor (bFGF) acts centrally in the brain to inhibit gastric emptying in rats.

In the present study, we evaluated the central nervous system action of basic fibroblast growth factor (bFGF) on gastric emptying of a liquid meal in conscious rats using a Phenol red method. Intracisternal injection of bFGF dose-dependently inhibited gastric emptying, while intraperitoneal injection of bFGF at the same doses failed to alter gastric emptying. These results suggest for the first time that bFGF acts in the central nervous system to delay gastric emptying.

Animals↗

Growth hormone deficiency and empty sella syndrome in a boy with dup(X) (q13.3----q21.2).

A 2 8/12-year-old boy with severe growth failure and mental retardation was found to have a maternally derived tandem duplication of the long arm of X chromosome, dup(X) (q13.3----q21.2). Karyotypic interpretation was further confirmed in this patient by a double gene dose for red blood cell phosphoglycerate kinase. DNA replication study showed that the duplicated X chromosome was always late replicating in peripheral blood lymphocytes as well as in skin fibroblasts from the mother. Endocrine studies in the patient demonstrated growth hormone deficiency. Magnetic resonance imaging of the head then disclosed the empty sella syndrome. This appears to be the first report of a dup(Xq) patient associated with a growth hormone deficiency and the empty sella syndrome. We emphasize that duplication of the proximal Xq in males represents another microduplication syndrome (Thode-Leonard syndrome).

Child, Preschool↗

Unique karyotypes in two patients with Prader-Willi syndrome.

A physical disruption of the Prader-Willi syndrome (PWS) chromosome region is thought to cause PWS. We describe 2 girls with PWS phenotype, who had unique chromosome 15 abnormalities. The first patient showed mosaicism: 45,XX,t(15;15)(qter----p11.1::q11.200----qter)/46,XX,t(15;15)(qter----p1 1.1::q 11.200----qter), +mar. The band 15q11.2 apparently remained intact in the t(15;15) chromosome, and the mar chromosome was considered as r(15) (p11.1q11.1). The second patient had a karyotype of 47,XX,del(15)(q11.200----q11.207), +idic (15)(pter----q11.1::q11.1----pter). The complex breakage and reunion involving the 15q11.2 regions of the father's homologous chromosomes 15 at meiosis appeared to have resulted in the idic(15) and the del(15) chromosomes. These cytogenetic findings suggest that the PWS chromosome region may be localized on the very proximal portion of band 15q11.2.

Child↗

The gastric antisecretory action of lipopolysaccharide is blocked by indomethacin.

We have recently found that bacterial lipopolysaccharide (LPS) at minute doses inhibits the secretion of gastric acid and pepsin in rats. The present study was performed to examine the mechanism by which LPS exerts its antisecretory action. The i.p. injection of LPS resulted in a dose-dependent (40-4000 ng/kg) decrease in gastric acid output in pylorus-ligated rats. However, preinjection of indomethacin (2-10 mg/kg s.c.), an inhibitor of prostaglandin biosynthesis, prevented the LPS-induced inhibition of gastric secretion in a dose-related manner, while these concentrations of indomethacin by themselves did not affect gastric acid output. These results suggest that LPS requires an intact prostaglandin system to exhibit its inhibitory action on gastric secretion.

Animals↗

Release of heptapeptide toxin (microcystin) during the decomposition process of Microcystis aeruginosa.

The decomposition process of toxic blue-green alga (cyanobacteria), Microcystis aeruginosa, under dark and aerobic condition was investigated in relation to the change of the amounts of heptapeptide toxins (microcystins YR and LR) by two experiments: one with Microcystis cells and the other with two purified microcystins. In the experiment with Microcystis cells, an increase of heterotrophic bacteria observed from the beginning of the experiment, was followed by decomposition of the algal cells and the subsequent release of microcystins into the filtrate fraction. The amounts of the toxins initially present in the cells were quantitatively detected in the filtrate fraction on the 35th day. The decomposition of microcystin YR began on the 42nd day. The decomposition rate of the two toxins was different. The decomposition rate of purified microcystins YR and LR, compared in distilled water and culture medium, respectively, indicated clearly that microcystin YR was more labile to decomposition than microcystin LR in the culture medium. At the end of the experiment (45th day) microcystin YR decreased to 58.6%, while 86.2% of microcystin LR remained.

Bacterial Toxins↗

Search for MHC-associated genes in human: five new genes centromeric to HLA-DP with yet unknown functions.

Taking advantage of five mouse genomic or cDNA probes [KE5(probe 14), KE4 (probe 11), KE3 (probe 7), KE2 (probe 5), and SET] mapped on the H-2K region in mouse, we have identified and localized homologues of these five genes in the human major histocompatibility complex region (HKE5, HKE4, HKE3, HKE2, and HSET, respectively). Cosmid cloning and pulsed field gel electrophoresis analyses indicated that a human homologous gene, HKE5, is located 10 kilobases (kb) centromeric of the alpha 2 (XI) collagen (COL11A2) gene followed by HKE4. HKE3, closely linked to HKE2, is located 170 kb centromeric of HKE4. Furthermore, HSET is located 50 kb centromeric of HKE2. This gene organization outside the DP subregion is completely identical to that of the mouse H-2K region centromeric of I-Pb3, a mouse homologue of the DPB gene, except the lack of genes corresponding to the H-2K and -K2 genes in human.

Blotting, Southern↗

A possible association between basic amino acids of position 13 of DRB1 chains and autoimmune hepatitis.

Fifty-one patients with autoimmune hepatitis have been studied for HLA association by conventional serology and also by modified polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotyping. HLA-DR4 was significantly associated with autoimmune hepatitis (46 of 51 patients, 90.2%). DNA typing of the DRB1 gene for 43 DR4-positive patients by using the PCR-RFLP technique revealed that of 43 patients, 33 had DRB1*0405 (Dw15), five had DRB1*0406 (DwKT2), four had DRB1*0403 (Dw13a), two had DRB1*0401 (Dw4), two of 43 had DRB1*0407 (Dw13b) and one had DRB1*0408 (Dw14b). Thus, there was no significant difference in Dw frequencies between DR4-positive patients and DR4-positive healthy subjects. These findings suggest that the DR4-specific sequence (Val 11 and His 13 at amino acid positions 11 and 13, respectively), but not particular Dw-associated DR4 sequence, in the first domain of the DRB1 chain contributes to susceptibility to autoimmune hepatitis among Japanese. Interestingly, all five of the DR4-negative patients had the DR2 specificity (DRB1*1502 or 1601). Taken together, these results imply that the basic amino acids at position 13, which is present only on the DR2 and DR4 B1 molecules (Arg on DR2 and His on DR4), are most important for determining the predisposition to autoimmune hepatitis.

Amino Acid Sequence↗

De novo complex chromosome rearrangement in identical twins with multiple congenital anomalies.

A de novo and apparently balanced complex chromosome rearrangement (CCR) was found in monozygotic (MZ) twin infants with multiple congenital anomalies. The rearrangement involved 4 chromosomes with 6 breakpoints including 2p23, 2q13, 2q21.1, 3p23, 11q13.1, and 12q24.1. This seems to be the first report of a CCR in MZ twins. The relationship between this chromosome abnormality and MZ twinning is discussed.

Abnormalities, Multiple↗

Evidence that gastric antisecretory action of lipopolysaccharide is not due to a toxic effect on gastric parietal cells.

We have recently found that bacterial lipopolysaccharide (LPS) or endotoxin at minute doses inhibits the secretion of gastric acid and pepsin in rats. The present study was performed to determine whether this antisecretory action of LPS was a reversible biological response or a result of the destruction of gastric parietal cells by endotoxin. The intraperitoneal injection of LPS into pylorus-ligated rats resulted in a dose-related (40-4000 ng/kg) decrease in gastric acid secretion, with maximal inhibition being observed at a dose of 4000 ng/kg. The stomach then was examined both macroscopically and microscopically for the presence or absence of mucosal lesions or damaged gastric parietal cells. No morphological changes in the gastric mucosal structure including parietal cells were observed even in the rats injected with 4000 ng/kg of LPS. Next, basal gastric acid output was compared in the rats that had received LPS (4000 ng/kg, intraperitoneal) or saline alone 24 hr before. There was no significant difference in gastric acid secretion between the saline- and LPS-pretreated groups, indicating that the secretory capacity of gastric parietal cells returned to the control level at 24 hr after the injection of a maximal antisecretory dose of LPS. These results clearly suggest that the LPS-induced inhibition of gastric secretion results not from its toxic or destructive effect on the gastric secretory mechanism but from its reversible biological effect on gastric physiology.

Animals↗

Glucagon, insulin and somatostatin secretion in response to sympathetic neural activation in streptozotocin-induced diabetic rats. A study with the isolated perfused rat pancreas in vitro.

Changes in glucagon, insulin and somatostatin secretion induced by electrical splanchnic nerve stimulation were examined in rats treated with streptozotocin as neonates and as adults. In order to study the direct neural effects we used the isolated perfused rat pancreas with intact left splanchnic nerve in vitro. In normal rats splanchnic nerve stimulation causes significant decreases in insulin (30-40%) and somatostatin (30-50%) secretion at both 16.7 mmol/l and 1 mmol/l glucose concentrations. In the neonatal streptozotocin-diabetic rat splanchnic nerve stimulation at 16.7 mmol/l glucose decreased insulin secretion (14%) further than in the control rats (30%), however, somatostatin secretion did not decrease to the same extent. Similar results were also observed at the low (1 mmol/l) glucose concentration. On the other hand, percent decreases of insulin and somatostatin secretion induced by splanchnic nerve stimulation in the streptozocin-diabetic rats were similar to the values observed in the normal control rats. The glucagon secretion in response to splanchnic nerve stimulation at 16.7 mmol/l glucose from pancreatic Alpha cells in both types of induced diabetes is exaggerated, and the degree of exaggeration seems to parallel the severity of the hyperglycaemia. However, the splanchnic nerve stimulation-induced glucagon secretion at 1 mmol/l glucose was impaired in the streptozotocin-diabetic rats, but not in the neonatal streptozotocin-diabetic rats. These data suggest that the sensitivity of diabetic Alpha and Delta cells to sympathetic neural activation are blunted, whereas the sensitivity of Beta cells is enhanced in the diabetic animal model.

Animals↗