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Biomedical subjects

K Kashima

Publications and source records attributed to K Kashima.

At least 181 records · Page 10Linked to original sources
PubMed1996

Detection and quantification of TEL/AML1 fusion transcripts by polymerase chain reaction in childhood acute lymphoblastic leukemia.

We investigated TEL/AML1 fusion mRNA in 108 children with acute lymphoblastic leukemia (ALL) (86 B-lineage ALL, 15 T-ALL, two mixed lineage ALL, and five other phenotypes) using reverse transcriptase-polymerase chain reaction (RT-PCR). TEL/AML1 transcripts were found in 14 patients (13%) including three relapsed patients, and were unexceptionally limited to B-lineage ALL patients. The incidence of TEL/AML1 transcripts among B-lineage ALL was 16% (14/86). The reciprocal AML1/TEL transcripts were detected in 12 (86%) of the 14 cases expressing a TEL/AML1 transcript. In three cases, the TEL gene was fused to exon 3 of the AML1 gene, and to exon 2 in the remaining cases. To evaluate the amount of TEL/AML1 molecules for the quantification of a minimal residual disease (MRD), a plasmid vector which contained either a long TEL/AML1 PCR product (464 bp) or a short one (425 bp) was used as a competitor. We amplified RNAs obtained from bone marrow (BM) at complete remission or from peripheral blood stem cell (PBSC) harvests in two representative cases. For one PBSC harvest showing a positive result, a competitive PCR was carried out to quantify the amount of MRD. A 1:4 dilution series of competitor vectors was constructed, and each vector was added to a PCR reaction which contain a constant amount of cDNA obtained from the PBSC harvest. An equivalent point was compared to that of corresponding samples at diagnosis. Using this method, MRD in the PBSC harvest was 3.9:10(3). Our results elucidated the incidence, lineage-specificity, and variant forms of TEL/AML1 fusion transcripts in childhood ALL. Since the percentage of other chromosomal translocations in childhood ALL is not more than 5%, TEL/AML1 transcript would be the most feasible clone-specific marker for these patients. In addition, our method could be a powerful tool for quantification of the TEL/AML1 transcript and for the detection of MRD.

Adolescent↗
PubMed1996

Taurine in the liver. The function of taurine conjugated with bile acids.

1. Taurine had cytoprotective effects on hepatocytes under hyperoxic or hypoxic condition in the presence of Ca2+. 2. Bile acids had toxic effects on hepatocytes; there was no significant difference in the toxicity between free bile acids and taurine-conjugated bile acids. 3. The mobility of the membranes, examined by 31P-NMR, decreased after treatment with taurine or free bile acids, but increased after treatment with taurine-conjugated bile acids. 4. The fluidity of the membranes, measured by ESR, did not change after treatment with taurine, but decreased after treatment with free bile acids and increased after treatment with taurine-conjugated bile acids. In conclusion, because most bile acids are conjugated with taurine in the liver after administration of taurine, the influence of taurine-conjugated bile acids has to be taken into consideration in estimating the functions of taurine in the liver.

Animals↗
PubMed1996

Internal tandem duplication of the flt3 gene found in acute myeloid leukemia.

We analyzed mRNA expression of the flt3 gene in 30 patients with acute myeloid leukemia (AML) and 50 with acute lymphoblastic leukemia (ALL). Using reverse transcriptase-polymerase chain reaction (RT-PCR), expression of flt3 was observed in 61 patients; 22 (73%) with AML and 39 (78%) with ALL. Among these, five patients with AML (one M2, two M4, and two M5) showed unexpected longer transcripts with a primer combination which could amplify the transmembrane (TM) domain through the juxtamembrane (JM) domain. For those patients who expressed flt3 mRNA, the extracellular domain of the flt3 gene was also examined by RT-PCR, but no length abnormality was seen in this region. We further analyzed the TM domain through the second tyrosine kinase domain by genomic amplifications. The five patients who showed aberrant flt3 transcripts exhibited abnormal longer PCR products in addition to the germline products at a region corresponding to the JM through the first TK (TK1) domains. Sequence analyses of the abnormal RT-PCR products demonstrated that partial sequences were tandemly duplicated. Because all these altered transcripts were in-frame, deduced protein products could be expected. Sequence analyses of the genomic DNA revealed that three of the five patients showed a simple internal duplication within exon 11; one had an internal duplication (26 bp) with a 4-bp insertion; and in the fifth patient, a 136-bp sequence from the 3' part of exon 11 to intron 11 and the first 16-bp sequence of exon 12 were each duplicated with 1-bp insertion. In order to confirm the tumor specificity of these alterations, DNA samples obtained at complete remission were also analyzed in the three patients harboring an flt3 duplication, but no abnormal PCR product other than germline was detected in any of the samples. Our results suggest that an internal tandem duplication at the JM/TK1 domains of the flt3 gene is a somatic change detected preferentially in AML, possibly containing a monocytic component.

Acute Disease↗
PubMed1995

Time course of the induction of VGF mRNA in the dorsal vagal complex in rats with cysteamine-induced peptic ulcers.

The time course of induction of VGF mRNA in the dorsal vagal complex of the medulla oblongata was investigated in rats with duodenal ulcer induced with cysteamine by in situ hybridization histochemistry. In control rats, weak VGF mRNA signals were detected in a few neurons in the nucleus tractus solitarii and dorsal motor nucleus of vagus. After the cysteamine administration (450 mg/kg, s.c.), VGF mRNA signals began to increase after 3 h, reached at peak level at 12 h, and decreased slightly at 24 h, but remained high after 48 h. The time course of duodenal ulcer score was absent at 3 h, very low at 6 h, about grade 1 at 12 h, and grade 2 or more at 24 and 48 h. The present results support the hypothesis that the increase of the central neuronal activity of the vagus nerve precedes ulcer generation in the duodenum.

Analysis of Variance↗
PubMed1995

TP53 mutations emerge at early phase of myelodysplastic syndrome and are associated with complex chromosomal abnormalities.

We examined TP53 mutation in 57 patients with myelodysplastic syndrome (MDS) at either the MDS phase or at the terminal leukemic phase using polymerase chain reaction-mediated single-strand conformation polymorphism (PCR-SSCP) analysis. TP53 mutations within exons 5 through 8 were found in seven patients. All these mutations were detected at the presentation of MDS whether these patients showed leukemic transformation or not. TP53 mutations were frequently found in patients with loss of the short arm of chromosome 17 (17p-) (three of seven patients with 17p-, 43%) and complex karyotypic abnormalities (five of 14, 38%). Among the seven patients with the TP53 mutation, four patients progressed to acute leukemia within 7 months from the diagnosis of MDS, and the remaining three died within 7 months without leukemic transformation. These findings suggest that mutations of the TP53 can be implicated in leukemic transformation and a poor prognosis in MDS.

Acute Disease↗
PubMed1995

The kinetics of copper-zinc superoxide dismutase in experimentally induced ischemia-reperfusion injury of the canine jejunum.

In this study, the kinetics of copper-zinc superoxide dismutase (CuZn-SOD) in experimentally induced ischemia-reperfusion injury of the canine jejunum were examined using immunohistochemical procedures, and evaluated as an index for the viability of transplants. A pedicled jejunal graft was subjected to arterial reperfusion after clamping the supplying blood vessels for 30 min. Under nonischemic conditions, some of the goblets in the goblet cells and the mucin covering the surface of the villi were stained positively with luxol fast blue, von Kossa, and immunohistochemistry for CuZn-SOD. Between 5 and 30 min after reperfusion, the appearance of goblets with positive immunoreaction for CuZn-SOD in the intestinal glands and the disappearance of these goblets in the villi were observed in the grafts of animals that received arterial reperfusion after 30 min of clamping of the arteries and veins at room temperature. Thereafter, the former disappeared gradually and the latter returned toward the nonischemic condition. The administration of allopurinol led to a decrease in tissue damage and a significantly higher number of goblets with positive immunoreaction for CuZn-SOD than in untreated animals. Furthermore, the goblets in the intestinal glands showed a negative reaction for CuZn-SOD 5 to 30 min after reperfusion. Preservation at 4 degrees C during ischemia revealed similar results to those observed in the animals given allopurinol. Thus, the distribution and intensity of CuZn-SOD positive goblets seems to be a useful indicator for the evaluation of tissue damage induced by free radicals mediating ischemia-reperfusion injury.

Allopurinol↗
PubMed1995

Electron microscopic study of endogenous peroxidase activity in human liver macrophages.

We evaluated the conditions of fixation for ultrastructurally demonstrating the endogenous peroxidase (PO) activity of macrophages in biopsied human liver. The application of microwaving and immersion fixation with tannic acid and aldehydes allowed excellent visualization of PO activity in the nuclear envelope (NE), rough endoplasmic reticulum (rER), and cytoplasmic granules (CG), with good preservation of cellular ultrastructures. The macrophages with PO activity showed one of the following five patterns of PO localization: positive in both the NE and rER but negative in the CG (type 1); negative in both the NE and rER but positive in the CG (type 2); negative in the NE but positive in both the rER and CG (type 3); positive in all three (type 4); PO negative (type 5). The type 1 cells resembled typical Kupffer cells, type 2 cells monocytes, and type 3 and 4 cells the exudate-resident macrophages considered to be a transitional form between exudate and resident macrophages. Type 5 cells may also be a transitional form between the exudate and resident macrophage, or an end-stage macrophage derived from exudate macrophages which have lost their PO activity. Tannic-acid-aldehyde immersion fixation with microwaving may be a useful method in the study of the PO activities of macrophages in biopsied human liver specimens.

Cell Nucleus↗
PubMed1995

Monokine production by peripheral whole blood in chronic hepatitis C patients treated with interferon.

Using our scoring system, we studied the production of monokines (interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6) by lipopolysaccharide-stimulated peripheral whole blood in 34 patients with chronic hepatitis C during the interferon-alpha/beta therapy. It decreased in 25.7% (9/35 group A), fluctuated in 60.0% (21/35, group B), and increased in 14.3% (5/35, group C). The patients in group A were younger than those in group B (P < 0.05). The histological grade of injury was milder in group A than in group B or C. The rate of sustained response was 66.7% (6/9) in group A, 19.0% (4/21) in group B, and 40.0% (2/5) in group C(P = 0.0184, group A versus group B). In summary, monokine production by peripheral whole blood varied during interferon therapy for chronic hepatitis C patients. No significant change was noted in 60% of the patients. However, patients with decreased monokine production were younger, with a mild histological grade, and likely to respond to the interferon therapy.

Adult↗
PubMed1995

Detection of anti-cord factor antibodies in intestinal tuberculosis for its differential diagnosis from Crohn's disease and ulcerative colitis.

We have developed a diagnostic method for pulmonary tuberculosis by detecting antibody to cord factor using enzyme-linked immunosorbent assay (ELISA). This study was to evaluate the usefulness of our method for a diagnosis of intestinal tuberculosis, and especially its ability to differentiate this disease from other inflammatory bowel diseases. Antibodies of the immunoglobulin G class against cord factor (trehalose-6,6'-dimycolate) from 27 patients with intestinal tuberculosis, 16 patients with Crohn's disease (CD), and 27 patients with ulcerative colitis (UC) were tested by ELISA with cord factor purified from Mycobacterium tuberculosis H37Rv as the antigen. Twenty-three of the 27 patients with intestinal tuberculosis (85%) showed elevated values distinct from healthy controls. None of the patients with CD showed an elevation of antibody titers. Of the 27 patients with UC, 26 (96%) did not show any anti-cord factor antibody elevation. We conclude that this method is simple and results are reproducible. The results of our study justify undertaking the detection of anti-cord factor antibodies to diagnose intestinal tuberculosis.

Adult↗
PubMed1995

A case of gastric antral vascular ectasia--increase of neuroendocrine cells in the antrum.

We report an 82-year-old woman with severe iron deficiency anemia who was found to have gastric antral vascular ectasia (GAVE). As she required repeated blood transfusion for the anemia and did not respond to various medical treatments, she was referred for antrectomy. The pathogenesis of GAVE is still obscure and may involve many factors. In our patient, immunohistochemical studies of the resected stomach disclosed a marked increase of neuroendocrine cells. The majority of these hyperplastic neuroendocrine cells, furthermore, showed immunoreactivity for 5-hydroxytryptamine (serotonin). These findings suggest that neuroendocrine mediators, serotonin in particular, may have been responsible for the local vasodilation.

Aged↗
PubMed1995

Neurofibromatosis 1 gene (NF1) mutation is a rare genetic event in myelodysplastic syndrome regardless of the disease progression.

Neurofibromatosis 1 gene (NF1) is a tumor suppressor gene and the product of which down-regulates Nras protein by its GTPase activating protein-related domain (NF1-GRD). Although the incidence of NF1 mutation was reported to be rare in the chronic phase of myelodysplastic syndrome (MDS), there have been no previous reports on its configuration in patients showing the disease progression. We examined NF1 in 50 patients with MDS including 9 who had progressed to more advanced stages and 16 to acute leukemia. Six patients had an Nras mutation. We carried out allele specific restriction analysis (ASRA) to detect a mutation at the first nucleotide A of codon 1423 (AAG), a mutational hot spot. We also employed a polymerase chain reaction mediated single strand conformation polymorphism (PCR-SSCP) method to confirm the result of ASRA and to detect a point mutation in other sequences of FLR exon. In consequence, ASRA disclosed wild type configuration and PCR-SSCP showed no aberrant band in any sample examined whether the samples harboured an Nras mutation or not. We conclude that NF1 mutation does not play a crucial role in the development and the progression of MDS.

Base Sequence↗
PubMed1995

Double mutations of the N-ras gene in a patient with acute myelomonocytic leukemia.

We report a patient with acute myelomonocytic leukemia (AMMoL) who showed two independent point mutations of the N-ras gene at codons 12 and 13. Longitudinal analysis revealed that one mutation at codon 13 was detectable throughout his disease course and the other at codon 12 emerged as a second mutation 14 months after the diagnosis was made, at the refractory stage. Cloning to vector and subsequent sequencing confirmed that these mutations occurred in different alleles. Chromosome findings showed a simple abnormal karyotype at presentation and further karyotypic aberrations during his disease course, concomitantly with the second mutation of the N-ras gene. These findings revealed a close relationship among the disease progression, karyotypic evolution and a newly-appearing N-ras mutation.

Aclarubicin↗
PubMed1995

Characterization of a 14q+ marker chromosome in philadelphia chromosome positive acute lymphoblastic leukemia by DNA analysis and fluorescence in situ hybridization.

We report a case of precursor-B acute lymphoblastic leukemia (ALL) with the Philadelphia chromosome (Ph) and a 14q+ chromosome whose additional material was a part of the long arm of der(9)t(9;22). A minor population carrying the standard Ph translocation without the 14q+ was also observed at the first presentation. The translocation of the BCR gene from chromosome 22 to the subtelomeric region of the 14q+ was confirmed by fluorescence in situ hybridization (FISH) using a yeast artificial chromosome (YAC) clone containing the BCR gene. The breakpoint of chromosome 14 could not be determined exactly but probably was at 14q24 or 14q32 by conventional chromosome analysis. Nevertheless, FISH using a YAC clone containing the human immunoglobulin heavy chain (IgH) gene locus, Southern blot, and pulsed-field gel electrophoresis (PFGE) analyses with IgJH probe, and loss of heterozygosity analysis at the alpha 1-antitrypsin (AT) gene locus showed lack of involvement of the IgH gene in the 14q+ and more centromeric breakage than the alpha 1-AT locus at 14q32.1. Thus, the formation of the 14q+ seemed to be a secondary genetic event after the Ph translocation and presumably played a minor role in the pathogenesis of B-cell malignancy in this case.

Base Sequence↗
PubMed1995

Hemizygous expression of the wild-type p53 allele may confer a selective growth advantage before complete inactivation of the p53 gene in the progression of chronic myelogenous leukaemia.

We analysed the expression of the p53 gene in various clinical phases of chronic myelogenous leukaemia (CML) by quantitative reverse transcriptase (RT) polymerase chain reaction (PCR). Hemizygous expression of the wild-type p53 allele was observed in two samples showing the loss of one p53 allele, and affected p53 expression was associated with p53 allelic loss rather than the clinical phase of CML. In four patients with CML showing p53 inactivation, we performed a detailed sequential analysis of p53 allelic loss, p53 mutation and expression from the onset of the disease to the patients' death. Consequently, we demonstrated that the loss of a wild-type p53 allele preceded mutation of the remaining allele, and that cells hemizygous for the wild-type p53 allele dominated those with both wild-type alleles, then were replaced by cells with complete p53 inactivation. These observations indicate that not only complete p53 inactivation but also hemizygous expression of the wild-type p53 allele may confer a selective growth advantage, and that the former is implicated in a more malignant phase than the latter. Alternatively, the inactivation of another undefined anti-oncogene on chromosome 17p may allow selective growth before the p53 mutation occurs.

Alleles↗
PubMed1995

Augmented endogenous nitric oxide production in partial portal vein-ligated rats.

1. Endothelium-derived nitric oxide (NO) is a potent vasodilator. Because the body oxidizes it to nitrate ions, NO3-, measurement of the serum concentration and the urinary excretion of NO3- may be an index for endogenous NO. We investigated the role of NO on hyperdynamic circulation in cirrhotic and partial portal vein-ligated rats by measuring NO3. 2. Liver cirrhosis was induced by administration of thioacetamide. Systemic and splanchnic haemodynamics and splenic-systemic shunting were determined by tracer microspheres. The concentration of NO3- was measured by using high-performance liquid chromatography with an anioncolumn. 3. We found that systemic and splanchnic hyperdynamic circulation existed to almost the same extent in cirrhotic and in portal vein-ligated rats as compared to the controls and shamoperated rats, respectively. Splenic-systemic shunting was markedly greater in portal vein-ligated rats than in cirrhotic rats. 4. Serum NO3- levels and urinary excretion of NO3- in cirrhotic rats tended to increase as compared to the controls. On the other hand, the levels in portal vein-ligated rats were significantly increased as compared to those of the shamoperated rats, and were significantly and negatively correlated to the splanchnic arterial resistance and total vascular resistance. The amount of urinary excretion of NO3- significantly correlated to splenic-systemic shunting (r = 0.61, P < 0.05) only in portal vein-ligated rats. 5. We suggest that these high levels of NO3- in portal vein-ligated rats relate to the extensive formation of porto-collateral vasculature or acute changes in systemic and splanchnic haemodynamics due to portal vein-ligation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗