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N Kamada

Publications and source records attributed to N Kamada.

At least 145 records · Page 8Linked to original sources
PubMed1996

New immunosuppressive proteins (KX-2, -4, and -5) induced by liver transplantation.

The presence in rat serum of three novel immunosuppressive proteins is associated with induction of tolerance after liver grafting. One of these, KX-5 (40 kilodalton molecular weight) is present 40-100 days after grafting of DA liver into PVG, a combination in which liver grafts are not rejected; two others, KX-2 (87 kilodaltons) and KX-4 (10 kilodaltons), are present in PVG sera in a retransplantation model. N-terminal amino acid sequencing indicated that none of the proteins had been described previously. Induction of KX-5 was inhibited by cyclosporin A. All three proteins inhibited mixed lymphocyte responses nonspecifically. Administration of a single dose of 300 micrograms purified KX-5 to PVG rats receiving heterotopic heart allografts led to prolonged graft acceptance. The results raise the possibility of clinical application of the immunosuppressive properties of liver grafts through administration of soluble proteins.

Amino Acid Sequence↗
PubMed1996

Increased Evi-1 expression is frequently observed in blastic crisis of chronic myelocytic leukemia.

Evi-1 is a transforming gene originally identified in a common integration site of murine leukemia retrovirus and mapped in human chromosome 3q26. It is not normally expressed in either human or murine hematopoietic cells, but is overexpressed in retrovirus-induced murine myeloid leukemias as well as human myeloid leukemias with 3q26 abnormalities, and thus thought to be responsible for both human and murine leukemogenesis. In this study, possible involvement of the Evi-1 gene in human leukemias was evaluated by Northern blot analysis in a total of 73 patients with various types of leukemias. We found that increased expression of the Evi-1 gene was most frequently observed in patients with CML in blastic crisis. It was found in 10 of 14 (71.0%) samples from CML in blastic crisis, three of 15 (20.0%) from acute myelocytic leukemia, three of 11 (27.3%) from MDS-derived leukemia, and one of 11 (9.1%) from acute lymphoblastic leukemia. Among 18 patients showing increased Evi-1 expression, none of 17 informative patients showed cytogenetic abnormalities involving 3q26. In addition, Southern blot analysis revealed neither amplification nor rearrangements of the Evi-1 gene in 11 Evi-1-positive patients whose DNA samples were available. Our results suggest that increased expression of the Evi-1 gene may play an important role in development of human leukemias, especially in progression from chronic phase to blastic crisis of CML even without 3q26 abnormalities.

Adult↗
PubMed1996

[Neoplasias in hematopoietic tissues].

Leukemia-specific chromosomal aberrations are the most reliable tumor markers. Although chromosome analysis is a powerful diagnostic tool, some aberrations like monosomy 7 in AML, 15; 17 translocation in APL and trisomy 12 in CLL are not adequately detected. Fluorescence in situ hybridization is a recent method to detect specific genetic alteration in both interphase and mitoic cells and overcomes the disadvantages of conventional cytogenetics, Southern blotting and RT-PCR. In this manuscript, the advantages and limitations of the methods used for detecting leukemia/lymphoma specific chromosomal markers were discussed.

Chromosome Aberrations↗
PubMed1996

Different methylation patterns of the M-BCR gene in myeloblastic and lymphoblastic crisis of chronic myelocytic leukemia.

OBJECTIVE: To investigate the relationship between methylation status of M-bcr gene and transformation of chronic myelocytic leukemia (CML) from chronic to blastic phase. MATERIAL AND METHODS: The methylation patterns of M-bcr in 23 patients with Ph' positive CML were studied. DNAs extracted from mononuclear cells of both chronic and blastic phases (20 cases) or blastic phases only (3 cases), were doubly digested with restriction enzymes HpaII and BglII, hybridized with a 5'M-bcr probe labeled with 32p-deoxycytidine triphosphate, and autoradiographed. RESULTS: In all the patients with myeloblastic crisis, DNAs from both chronic and blastic cells of each patient showed identical methylation patterns. There was substantial heterogeneity in methylation patterns in the patients with lymphoblastic crisis. All the lymphoblastic patterns were distinct from the chronic patterns as well as the patterns shown in myeloblastic crisis. Moreover, in four out of six patients with lymphoblastic crisis, the chronic patterns were different from those in cases with myeloblastic crisis. CONCLUSIONS: The methylation status of M-bcr was stable during evolution of CML from chronic to myeloblastic phase. Analysis of M-bcr methylation status may be of clinical use in distinguishing lymphoblastic from myeloblastic crisis and predicting the cell lineage of crisis when the disease is still in its chronic phase.

Blast Crisis↗
PubMed1996

[Progress in diagnosis of leukemia].

Recent advances in molecular biological techniques have contributed to the tremendous progression made in the field of diagnosis of leukemia. Discovery of T- or B-lymphocyte associated genes, tumor specific genes and genes involved in chromosomal translocation has made it possible to detect leukemia cells by Southern blotting, PCR, RT-PCR or fluorescence in situ hybridization (FISH). The recently developed FISH is a simple, rapid and accurate method and requires a very small amount of specimen (about 500-1000 cells). It is possible to obtain results within 48 hours of sampling. This lecture were focused on two topics; 1) The application of FISH method in the diagnosis of leukemia using three types of probes (whole chromosome painting probe, centromeric probes and oncogene specific probes) and their combinations. 2) Clarification of concepts made by molecular biology especially in Philadelphia chromosome positive leukemia, Ph-negative chronic myelocytic leukemia, endemic/sporadic type of Burkitt's lymphoma, biphenotypic leukemia and leukemia with specific translocations.

DNA Probes↗
PubMed1996

Simple in situ hypothermia reduced ischaemic injury to human liver during hepatectomy.

OBJECTIVE: To assess the preventive effect of simple in situ cooling on ischaemic injury in human livers. DESIGN: Randomised study. SETTING: University department of surgery, Japan. SUBJECTS: 20 patients who were to undergo liver resection (right lobectomy, n = 6, left lobectomy, n = 3, and posterior segmentectomy, n = 1, in each group); all but 2 who had normal remnant livers and were randomised to undergo either warm ischaemia or in situ cooling (n = 10 in each group). INTERVENTIONS: Hypothermia was induced by rapid infusion of roughly 450 ml of cold Ringer's lactate into the portal vein during occlusion of the portal triad before resection. MAIN OUTCOME MEASURES: Occlusion time, ATP concentrations, biochemical indicators of liver damage, and coagulation profile. RESULTS: The mean (SD) occlusion time was 55 (6) minutes for the warm ischaemia group and 53 (3) for the in situ cooling group. After in situ cooling the state of the liver as indicated by serum alanine aminotransferase activity (ALT) and prothrombin time had improved substantially. Mean (SD) ALT activity was 516 (168) U/I in the warm ischaemia group compared with 305 (154) in the in situ cooling group (p < 0.02) on the first postoperative day. The respective figures for prothrombin time (%) were 56 (23) compared with 77 (14), (p < 0.05). CONCLUSION: In situ cooling lessened the amount of ischaemic damage done to the liver during hepatectomy compared with treatment with warm ischaemia.

Adult↗
PubMed1996

Powerful immunosuppression by a new 40-kd serum protein (KX-5) induced by liver transplantation.

The presence of novel immunosuppressive proteins in the serum of liver grafted rats is associated with the induction of tolerance. This may provide part of the explanation for the induction or maintenance of tolerance in this liver graft mode, although their relationship to the antigen-specific aspects of liver graft survival (clonal deletion of T cells, release of soluble class I antigen, production of anti-class II antibodies) remains to be investigated. The KX-5 protein was nonspecifically immunosuppressive in vivo, suggesting the possibility of harnessing the tolerogenic properties of liver grafts in a soluble form for clinical application.

Animals↗
PubMed1996

Abnormal expression of Evi-1 gene in human leukemias.

The human Evi-1 gene located on chromosome 3q26, encodes a zinc finger protein that functions as a transcription factor. It was frequently overexpressed in leukemias having 3q26 abnormalities such as t(3;3)(q21;q26) and inv(3)(q21 q26), and subjected to structural alteration in t(3;21)(q26;q22). In addition, recent studies indicated that several cases of leukemias without 3q26 abnormalities also expressed Evi-1 gene. In this study we present another case of structural alteration of Evi-1 gene in a case of inv(3)(q21 q26), in which Evi-1 was truncated and a shorter form of Evi-1 protein was expressed upon rearrangement of the gene. We also studied expression of the Evi-1 gene in a variety of leukemias by northern blot analysis. Evi-1 was overexpressed not only in leukemias with 3q26 abnormalities, but, in those without 3q26 abnormalities, especially in blast crisis of CML. Our result also supports an idea that Evi-1 is a relevant oncogene whose overexpression or structural changes might play a crucial role in development of human leukemias.

Adult↗
PubMed1995

Pancreatic beta-cell-specific targeted disruption of glucokinase gene. Diabetes mellitus due to defective insulin secretion to glucose.

Mice carrying a null mutation in the glucokinase (GK) gene in pancreatic beta-cells, but not in the liver, were generated by disrupting the beta-cell-specific exon. Heterozygous mutant mice showed early-onset mild diabetes due to impaired insulin-secretory response to glucose. Homozygotes showed severe diabetes shortly after birth and died within a week. GK-deficient islets isolated from homozygotes showed defective insulin secretion in response to glucose, while they responded to other secretagogues: almost normally to arginine and to some extent to sulfonylureas. These data provide the first direct proof that GK serves as a glucose sensor molecule for insulin secretion and plays a pivotal role in glucose homeostasis. GK-deficient mice serve as an animal model of the insulin-secretory defect in human non-insulin-dependent diabetes mellitus.

Alternative Splicing↗
PubMed1995

Loss of the cyclin-dependent kinase 4-inhibitor (p16; MTS1) gene is frequent in and highly specific to lymphoid tumors in primary human hematopoietic malignancies.

The cyclin-dependent kinase 4-inhibitor (CDK41; p16; or MTS1) gene has been proposed as a candidate for a tumor-suppressor gene located in chromosome 9p21, a frequently deleted region in a wide spectrum of human cancers, including leukemias. Recent studies disclosed that it was frequently deleted or mutated in a variety of primary human cancers, including acute lymphoblastic leukemia. The purpose of this study is to figure out the precise manners and frequencies of p16 gene inactivation in diverse hematopoietic tumor types and thus to clarify its significance in development of human hematopoietic malignancies. A total of 410 tumor specimens from patients with primary hematopoietic malignancies were examined for deletions of the p16 gene as well as the neighboring p15 gene and the nearby interferon alpha gene by Southern blot analysis. Tumor-specific mutations or small deletions of the p16 gene were also studied in 74 patients using single-strand conformation polymorphism analysis and direct sequencing. Loss of the p16 gene was most frequently observed among the three genes examined and was found in 59 of the 410 patients: 2 of 134 with acute myelocytic leukemia, 41 of 105 with acute lymphocytic leukemia, 2 of 15 with chronic lymphocytic leukemia, 5 of 14 with adult T-cell leukemia, 4 of 33 with non-Hodgkin's lymphoma, 3 of 8 with mixed-lineage leukemia, and 2 of 61 with chronic myelocytic leukemia. In 16 of the 59 patients, the p16 deletions occurred due to rearrangements within the small region between the p15 exon 2 and the p16 exon 2. Tumor-specific mutations or small deletions of the p16 gene were not detected in the 74 patients examined, including 12 of 14 patients with hemizygous deletions of the gene. Loss of the p16 gene is frequent in and highly specific to lymphoid malignancies (54 of 183 [30%] in lymphoid tumor v2 of 219 [1%] in myeloid tumors; P < .0001). The deletion analyses strongly suggest that the p16 gene is a tumor-suppressor gene located in chromosome 9p21 that is involved in development of human lymphoid tumors. Gene deletions but not minute mutations should be the predominant mechanism of p16 gene inactivation in these types of tumors.

Adolescent↗
PubMed1995

A randomized trial comparing interferon-alpha with busulfan for newly diagnosed chronic myelogenous leukemia in chronic phase.

A multicenter randomized study was conducted to compare the effect of interferon-alpha (IFN-alpha) with that of busulfan in newly diagnosed patients with chronic myelogenous leukemia (CML) in chronic phase. From October 1988 to October 1991, 170 patients were randomized to receive either IFN-alpha or busulfan. Of 159 eligible patients, 31 (38.8%) of 80 patients in the IFN-alpha group and 43 (54.4%) of 79 patients in the busulfan group achieved complete hematologic remission, and 38.8% in the IFN-alpha group and 43.0% in the busulfan group achieved partial hematologic remission. A complete cytogenetic response was induced in seven (8.8%) of 80 patients treated with IFN-alpha and two (2.5%) of 79 patients treated with busulfan, and a partial cytogenetic response was 7.5% (6/80) and 2.5% (2/79), respectively. The difference in major (complete and partial) cytogenetic response between the two groups was significant (P = .046). At a median follow-up of 50 months, the predicted 5-year survival rate was 54% in the IFN-alpha group and 32% in the busulfan group (P = .0290), and the predicted 5-year rate of remaining in chronic phase was 41% in the IFN-alpha group and 29% in the busulfan group (P = .1165). As compared with the patients with no cytogenetic response, the patients with any cytogenetic response (complete, partial or minor) after the IFN-alpha or busulfan treatment were significantly superior in the duration of chronic phase (IFN-alpha group; P = .0017, busulfan group; P = .0010) even after correction for the time to response using the landmark analysis. However, there was no significant difference in survival rate in the IFN-alpha group (P = .1065). There was no significant difference in survival rate (P = .3923) and the duration of chronic phase (P = .6258) between the IFN-alpha and the busulfan group in the patients with a cytogenetic response (complete, partial or minor). These results demonstrate that IFN-alpha treatment produces a significantly superior cytogenetic response and survival rate as compared with the busulfan treatment, and unexpectedly, that busulfan can also eliminate Philadelphia chromosome positive clone in a few patients who showed prolonged survival rate and duration of chronic phase.

Adult↗
PubMed1995

Establishment and characteristics of a gastric cancer cell line (HuGC-OOHIRA) producing high levels of G-CSF, GM-CSF, and IL-6: the presence of autocrine growth control by G-CSF.

We successfully established a human gastric cancer cell line, HuGC-OOHIRA, from the ascites of a 60-year-old patient with advanced gastric cancer (poorly differentiated adenocarcinoma) complicated by peritonitis carcinomatosa and leukocytosis of unknown origin. Morphologically, the cells were polygonal and adhered weakly to the culture flask. They tended to pile up upon reaching confluence. Chromosome analysis revealed that the cell line has two modes of chromosome number, namely near diploidy and tetraploidy. Double minutes (DMs) were present in abundance in each cell. The doubling time was 25-30 hr. The cell line was successfully transplanted into nude mice, and their peripheral leukocyte counts increased in proportion to the growth of the tumors. At 2 weeks after the transplantation, the serum rG-CSF level was elevated to 2,893 pg/ml. The concentration of human G-CSF in the culture supernatants was an extraordinary high level of 145,380 pg/ml/day. Secretion of GM-CSF and IL-6 was also detected. The intracellular localization of the G-CSF was identified for the first time by immunofluorescence. Moreover, Northern blot analysis detected G-CSF mRNA in this cell line. Anti-recombinant human G-CSF serum suppressed the propagation of HuGC-OOHIRA cell line. Therefore, it is likely that the autocrine growth loop by G-CSF is present in this cell line. This cell line would be very useful for understanding both the cellular and molecular basis for the production of various cytokines such as G-CSF as well as cytokine-dependent tumor proliferation.

Adenocarcinoma↗
PubMed1995

Identification of two transcripts of AML1/ETO-fused gene in t(8;21) leukemic cells and expression of wild-type ETO gene in hematopoietic cells.

The t(8;21) is a common chromosomal abnormality, preferentially associated with acute leukemia showing features of myeloid differentiation. Recently, two genes--AML1, which has a unique runt domain, and ETO (MTG8)--have been isolated from the chromosomal breakpoint. In this study, we isolated and identified two fused transcripts from a leukemic cell line carrying t(8;21). AML1 and ETO were fused at the same position in these transcripts. One of the transcripts codes a unique domain, including two zinc finger domains and three proline- and one leucine-rich region. The other transcript codes only for one proline- and leucine-rich region but lacks zinc finger domains. We demonstrated by polymerase chain reaction (PCR) analysis that 1) these two transcripts are consistently expressed in leukemic cells with t(8;21) obtained from patients and 2) expression of AML1 was not restricted to the particular stage of hematopoietic differentiation but was present in all hematopoietic cells investigated. We also provide evidence that two wild types of ETO transcripts containing the region of the ETO gene in fused transcripts are expressed in hematopoietic cells from different lineages. The widespread expression of AML1 and ETO in hematopoietic cells suggests a fundamental role of these proteins in hematopoiesis. Furthermore, the differences in the carboxy termini of ETO may modulate the activity of fused proteins resulting from the chromosomal translocation t(8;21).

Acute Disease↗
PubMed1995

Orthotopic liver retransplantation in rats.

A surgical experience with a method of rate orthotopic liver retransplantation (OLRT), and a preliminary study of immunological responses after OLRT are reported. OLRT was performed on the same recipient after the fist orthotopic liver transplantation (1st-OLT) according to our original (Kamada's) cuff method. Replacement of the portal vein (PV) and infra-hepatic vena cava (IHVC) cuffs was not technically difficult. However, there were no survivors from the first 6 retransplanted rats, mainly due to complications from defective supra-hepatic vena cava (SHVC) anastomoses. Unlike the human intra-abdominal SHVC, the posterior wall of the intra-abdominal SHVC in rats is too short and fragile to perform an end-to-end anastomosis twice between donor and recipient SHVC. For a second group of seven retransplants, a modification of the SHVC anastomosis was made between donor and recipient SHVC in conjunction with the recipient's cuff diaphragm. This enabled reanastomosis to be secure, resulting in the improved 1-week survival after isogenic OLRT (85.7%). This OLRT model has been applied to the fully allogeneic combination for several immunological studies and led to novel findings. Thus, an experimental model of a rat orthotopic liver retransplant model has the potential to allow more valuable insights into the immunological study of chronic rejection, sensitization and chimerism following liver retransplantation.

Anastomosis, Surgical↗
PubMed1995

Evidence that the elevation of soluble MHC class I antigens in the serum precedes the onset of graft-versus-host disease and is correlated with the severity of the disease in rats.

We examined the changes in the levels of soluble major histocompatibility antigen complex (MHC) class I antigens in the serum under a lethal or nonlethal state of graft-versus-host-disease (GVHD) induced by injecting various doses of PVG rat splenic lymphocytes into (DA x PVG)F1 rats. All rats receiving 4 x 10(8) lymphocytes (lethal dose) died on day 20-36 showing typical features of GVHD, while the injection of 4 x 10(7) cells (nonlethal dose) induced no sign of GVHD. When rats were inoculated with a nonlethal dose of lymphocytes prior to the injection of a lethal dose, all rats survived with or without showing transient GVHD. Preceding the onset of GVHD the levels of soluble class I antigens increased significantly to 1094 +/- 487 ng/ml (mean +/- SD, n = 4) from 3 days after the injection of a lethal dose to the time of death, whilst the levels in the nonlethal dose group remained unchanged. Rats with transient GVHD in the preinoculated group showed the increase of soluble class I antigens to the same extent as rats with lethal GVHD, suggesting that GVHD was systemically ongoing. The levels of soluble class I antigens also correlated with the severity of GVHD as judged by daily observation and histological studies. Rats receiving a lethal dose showed destructive alteration of spleen structure and cellular infiltration in the portal area of the liver before the animals started to show signs of GVHD, whereas rats in the nonlethal dose group exhibited no marked change. These data suggest the possibility of serum soluble class I antigens being not only a diagnostic but also a prognostic marker for GVHD.

Animals↗