Search PubMed⌕ Search

Biomedical subjects

Y Niitsu

Publications and source records attributed to Y Niitsu.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Hemolytic anemia and thrombocytopenia induced by cimetidine: recurrence with ranitidine administration].

A 69-year-old woman was admitted with apoplexy after operation of mitral valve stenosis and gastrectomy due to a gastric ulcer. In June 1994, her condition gradually worsened after acute pneumoniae in her right lung. Intravenous hyperalimentation with cimetidine administration was started to improve her undernourishment, because she had a history of gastric ulcer. However, after 10 days from the start of cimetidine therapy, anemia progressed rapidly. Biochemical examinations revealed that the serum indirect bilirubin and LDH levels were elevated and no serum haptoglobin was detected. These results indicated the development of hemolytic anemia, but at that time we could not clarify the reason. In October 1994, thrombocytopenia gradually progressed, and we halted the administration of cimetidine to ranitidine. Both hemolytic anemia and thrombocytopenia was dramatically improved after cessation of cimetidine administration. We then changed the drug from cimetidine, however the same phenomena have appeared again. The patient was in stable condition, after cessation of H2-blockers administration. The complication of hemolytic anemia and thrombocytopenia associated with H2-blocker administration in Japan.

Aged↗
PubMed1997

[Successful high-dose chemotherapy combined with autologous bone marrow transplantation in a case of refractory follicular lymphoma].

A 34-year-old patient with follicular lymphoma who was treated with CHOP followed by COPP for 3 years, became resistant to treatment in December 1993. Histological findings and surface markers of cervical lymph node cells revealed no change from previous findings. Tumor cell involvement of bone marrow was also observed by molecular analysis of DNA fragments with bcl-2 oncogene and J-H gene probes. Following 2 courses of salvage chemotherapy with NOAC-M regimen (novantrone, cytarabine and methylprednisolone), There was an 88% reduction of tumor mass on computed tomographic findings. Through the use of polymerase chain reaction analysis of residual cells with the bcl-2 translocation, we confirmed the in vivo purging of tumor cells from bone marrow and we harvested marrow cells for autologous transplantation. After high-dose chemotherapy (HDC) with ranimustine, cisplatin, etoposide and cyclophosphamide followed by bone marrow transplantation (BMT), complete remission was achieved. The patient has survived for 16 months and remains disease free. The standard chemotherapy regimen for advanced low grade non-Hodgkin's lymphoma has not yet been defined. Although we must follow this patient carefully to determine the effect of HDC with BMT for a long time, this seems to be an effective complementary treatment for patients responding to conventional salvage regimens.

Adult↗
PubMed1997

[TNF].

TNF exerts its biological activities through two distinct receptors of TNF-R55 and TNF-R75. Recent studies have identified TNF receptor-associated molecules, and intracellular signal transduction for apoptosis induced by TNF has been elucidated. Various TNF mutants with higher affinity to TNF-R55 and lower affinity to TNF-R75 are being clarified biogenetically. These mutants show lower adverse effect and higher antitumor activity. Furthermore, TNF gene transduction into lymphocytes and tumor cells shows a decrease in tumorigenicity and enhancement of host immunogenicity. This approach appears to be promising for cancer treatment.

Animals↗
PubMed1997

[Granulocyte colony stimulating factor (G-CSF) producing renal cell carcinoma].

A 88-year-old male patient with G-CSF producing renal cell carcinoma is reported. The patient was admitted to our hospital complaining of macrohematureia. The laboratory examination showed marked leukocytosis of 18,200/microliter (neutrophil 92%) in the peripheral blood and high levels of G-CSF (120 pg/ml) in the serum. An abdominal CT scan revealed a right renal tumor. The neutrophil count rose to 38,700/microliter with increasing of tumor size. Histopathological diagnosis was renal cell carcinoma (Grade 3) and immunohistochemical staining using Histo anti-G-CSF antibody demonstrated cancer cells produced G-CSF. This is the second case of G-CSF producing renal cell carcinoma diagnosed by immunohistochemical staining in the literature.

Aged↗
PubMed1997

[A case of pure red cell aplasia accompanied with granular lymphocytic leukemia the tumor cells of which suppressed colony formation of BFU-E, and which was successfully treated by cyclophosphamide and cyclosporin A].

A 69-year-old woman with pure red cell aplasia and granular lymphocytic leukemia was reported. Because her granular lymphocyte count was in the normal range at the time of admission, we diagnosed the patient as primary pure red cell aplasia (PRCA). The granular lymphocyte count increased slowly, and we find monoclonal T cell receptor rearrangement, the case was diagnosed as granular lymphocytic leukemia accompanied with PRCA. Although single administration of cyclosporin or cyclophosphamide induced severe side effects obtained combined administration of low doses of these agents obtained good Hb increase. This case was granular lymphocytic leukemia with normal granular lymphocytic count at the time of diagnosis, the tumor cell suppressed BFU-E colony formation, and combined administration of low dose CPM and CyA yielded good effects.

Aged↗
PubMed1997

[Thrombocytopenia associated with sodium polystyrene sulfonate].

A 84-year-old man was admitted with diabetes mellitus, hypertension and chronic renal failure in September 1994. In October 1995, his renal function gradually worsened with hyperkalemia. Sodium polystyrene sulfonate (Kayexalate) was administered orally for the treatment of hyperkalemia. However, after 7 days from the start of Kayexalate therapy, thrombocytopenia progressed gradually, and 12 days later the initial platelet count of 20.7 x 10(4)/microliter decreased to 8.6 x 10(4)/microliter. This thrombocytopenia rapidly improved after cessation of Kayexalate administration. In December 1995, readministration of Kayexalate for the treatment of hyperkalemia induced thrombocytopenia again. Bone marrow aspiration biopsy revealed normal counts of nucleated cells and megakaryocytes with no increase in blasts. No other disorders which cause thrombocytopenia were seen in this patient. The complication of thrombocytopenia associated with Kayexalate has not been reported. This is the first reported case of thrombocytopenia caused by Kayexalate administration.

Aged↗
PubMed1996

Hepatic iron deprivation prevents spontaneous development of fulminant hepatitis and liver cancer in Long-Evans Cinnamon rats.

Several clinical studies have suggested that excess hepatic iron accumulation is a progressive factor in some liver diseases including chronic viral hepatitis and hemochromatosis. However, it is not known whether iron-induced hepatotoxicity may be directly involved in hepatitis, cirrhosis, and liver cancer. The Long-Evans Cinnamon (LEC) rat, which accumulates excess copper in the liver as in patients with Wilson's disease, is of a mutant strain displaying spontaneous hemolysis, hepatitis, and liver cancer. We found previously that LEC rats harbored an additional abnormality: accumulation of as much iron as copper in the liver. In the present study, we compared the occurrence of hepatitis and liver cancer in LEC rats fed an iron-deficient diet (ID) with those in rats fed a regular diet (RD). The RD group showed rapid increments of hepatic iron concentrations as the result of hemolysis, characteristics of fulminant hepatitis showing apoptosis, and a 53% mortality rate. However, no rats in the ID group died of fulminant hepatitis. Hepatic iron, especially "free" iron concentration and the extent of hepatic fibrosis in the ID group were far less than those of the RD group. At week 65, all rats in the RD group developed liver cancer, whereas none did in the ID group. These results suggest that the accumulation of iron, possibly by virtue of synergistic radical formation with copper, plays an essential role in the development of fulminant hepatitis, hepatic fibrosis, and subsequent hepatocarcinogenesis in LEC rats.

Animals↗
PubMed1996

Transfection of glutathione S-transferase (GST)-pi antisense complementary DNA increases the sensitivity of a colon cancer cell line to adriamycin, cisplatin, melphalan, and etoposide.

The goal of this study was to demonstrate that glutathione S-transferase (GST)-pi is directly involved in the intrinsic and acquired resistance of cancer cells to anticancer drugs. To this end, GST-pi antisense cDNA was transfected into the cultured human colon cancer cell line M7609, which expresses an innately high level of GST-pi and shows intrinsic drug resistance, and into an M7609 strain with acquired resistance to Adriamycin (ADR;i.e., M7609/ADR cells). The changes in the sensitivity of these transfectants to various anticancer drugs were investigated. The intracellular concentrations of GST-pi in M7609/anti-1 cells and M7609/anti-2 cells, two clones that were established by transfection of GST-pi antisense cDNA into M7609 cells, were decreased to approximately half of those detected in the parent cells (M7609) and in the control cells transfected with vector alone (M7609/pLJ). The sensitivities of the antisense transfectants in relation to ADR, cisplatin, melphalan, and etoposide were increased -3.3-fold, 2.3-fold, 2.2-fold, and 2.1-fold, respectively, compared with those of M7609 and M7609/pLJ. On the other hand, the sensitivities of the antisense transfectants to Taxol, vincristine, 5-fluorouracil, and mitomycin C were not significantly changed. Similarly, the transfection of antisense cDNA into M7609/ADR cells resulted in the reduction of intracellular GST-pi concentration (by about half) and an increased sensitivity to ADR (4.4-fold), but no increase in 5-fluorouracil sensitivity. Thus, GST-pi is considered to be a multidrug resistance factor that is responsible for both the intrinsic and acquired resistance of cancer cells to anticancer drugs such as ADR, cisplatin, melphalan, and etoposide.

Antineoplastic Agents↗
PubMed1996

Glutathione S-transferase-pi is secreted as a monomer into human plasma by platelets and tumor cells.

By employing an ELISA for detection of glutathione S-transferase-pi (GST-pi) established in our laboratory, gel filtration profiles of GST-pi in the plasma of normal subjects and patients with malignant tumors were investigated. The results showed that the plasma GST-pi for both of these groups was approximately half the molecular size of placental GST-pi used as a standard control. Similar analyses were performed on GST-pi of platelets and cultured cancer cells, which are considered to be the main sources of the GST-pi in the plasma of normal subjects and cancer patients, respectively. The results indicated that the GST-pi in both the centrifuged supernatants of aggregated platelets and in the culture medium of cancer cells was about half of the molecular size on intact GST-pi. Moreover, the GST-pi in the culture medium was shown to have an N-terminus and a C-terminus, by analysis with specific ELISA. Western blot analysis of the GST-pi in the culture medium detected a single band migrating at 23 kDa, confirming that the extracellular GST-pi was the monomer, not a cleaved form of intact GST-pi. The release of GST-pi from cancer cells was suppressed at 4 degrees C, or by sodium azide, but not suppressed by colchicine or cytochalasin B. These findings suggest that GST-pi may be released by an energy-dependent, active process, and not by a secretion mechanism.

Blood Platelets↗
PubMed1996

Establishment of high- and low-invasion clones derived for a human tongue squamous-cell carcinoma cell line SAS.

Distant-organ metastasis and regional lymph node metastasis are still the major cause of mortality of oral-cavity squamous-cell cancer (SCC). However, only a few studies have been undertaken to elucidate the mechanism of invasion and metastasis of oral SCC. In this study, we attempted to establish human oral SCC clones with different invasiveness, defined by endothelial cell monolayer assay, which can be used for the study of invasion and metastasis of oral SCC. We established five clones from the human oral SCC cell line SAS by a limiting-dilution method. Two distinct clones, SAS-L1 with very low invasive potential and SAS-H1 with very high invasive potential, were picked out by rat lung endothelial cell monolayer assay. The number of SAS-H1 that penetrated the rat lung endothelial cell monolayer was six fold higher than the number of SAS-L1. There were no differences of metalloproteinase production and cell adhesiveness to Matrigel of SAS-L1 and SAS-H1. However, SAS-H1 exhibited a higher migration ability than SAS-L1. This pair of clones would be a useful experimental model to help in the study of the invasiveness of human oral SCC.

Basement Membrane↗
PubMed1996

Determining depth of invasion of advanced colorectal cancer using MRI short inversion time inversion recovery sequences.

To examine the usefulness of magnetic resonance imaging (MRI) in the preoperative determination of cancerous invasion, we examined 39 patients with advanced colorectal cancer with 0.5T MRI. We employed short inversion time inversion recovery (STIR) sequences, in addition to ordinary spin echo sequences for T1- and T2-weighted images. Preoperatively, the estimated depth of tumor invasion was classified into three grades according to MRI findings, and confirmed on the basis of surgical and histopathologic results. The depth of tumor invasion estimated preoperatively using STIR sequences corresponded well with the surgical and histopathologic results in 85% of the cases. In contrast, assessments based on T1-weighted images corresponded well in only 62% of the cases and T2-weighted images corresponded well in only 64%.

Colon, Sigmoid↗
PubMed1996

Bacterial adhesion on hydrophilic heparinized catheters, with compared with adhesion on silicone catheters, in patients with malignant obstructive jaundice.

To study the inhibitory effects on bacterial adhesion of a newly devised, hydrophilic heparinized catheter to be used in patients with malignant obstructive jaundice, a randomized controlled study of indwelling endoprostheses was performed, using implantable port-connected heparinized catheters (n = 25) and silicone catheters (n = 21). Catheters withdrawn from patients were cultured for bacteria and examined by electron microscopy for the presence of adherent organisms. In vitro examination of the two type of catheters exposed to suspensions of Eschericia coli and Staphylococcus aureus was performed using electron microscopy and a luminometer. The formation of a biofilm coated with glycocalyces was found in silicone catheters, but not in the heparinized catheters. In vitro experiments demonstrated little bacterial adhesion to the heparinized surface, but significant formation of biofilm on the silicone surface. Anionically charged heparinized catheters have inhibitory effects on bacterial adhesion, and the surface charge of the catheter may be a factor in inhibiting this adhesion.

Aged↗
PubMed1996

Endogenous tumor necrosis factor inhibits the cytotoxicity of exogenous tumor necrosis factor and adriamycin in pancreatic carcinoma cells.

Pancreatic carcinoma is one of the most devastating neoplasms with regard to its resistance to conventional therapy. In a previous report, we found that endogenous tumor necrosis factor (enTNF) exerts an intracellular protective effect against exogenous TNF- and Adriamycin (ADM)-induced cytotoxicity by scavenging oxygen free radicals (OFR) with induced manganous superoxide dismutase (MnSOD). We also know that glutathione S-transferase pi (GST-pi) and glutathione (GSH) also scavenge OFR. It remains unclear to what extent enTNF and MnSOD induced by enTNF regulate the sensitivity to ADM and exogenous TNF among different carcinoma cells. In this study, we examined the relationship between ADM and exogenous TNF sensitivity and en-TNF expression and MnSOD activity in four pancreatic carcinoma lines. We determined whether ADM and exogenous TNF sensitivity could be predicted by measuring enTNF expression and MnSOD activity in the carcinoma cells. The sensitivity to TNF and ADM varied with the cell lines, and TNF sensitivity correlated well with Adriamycin sensitivity. Moreover, enTNF expression and Mn-SOD activity correlated positively with resistance to ADM and exogenous TNF. When MIAPaCa-2 cells, which had the lowest enTNF expression and the highest sensitivity to exogenous TNF and ADM, were transfected with the nonsecretory-type human TNF gene (pTNF delta pro) to increase enTNF synthesis, their intracellular MnSOD activity and exogenous TNF and ADM resistance were increased. These findings suggest that MnSOD plays a critical role in scavenging OFR induced by ADM and exogenous TNF. enTNF is the most important factor that regulates the production of MnSOD. Therefore, it is plausible that inhibition of enTNF expression or MnSOD activity in pancreatic carcinoma would improve the efficacy of therapies for pancreatic carcinoma.

Doxorubicin↗
PubMed1996

Analysis of CA repeats in first intron of class I ADH gene in Long-Evans Cinnamon rats developing fatal intoxication after ethanol intake.

The Long-Evans Cinnamon (LEC) rat is a mutant strain established from Long-Evans rats that displays spontaneous hepatitis and liver cancer. We previously demonstrated that LEC rats died of acute ethanol intoxication after being fed a liquid diet containing 5% ethanol. Furthermore, we found that both alcohol dehydrogenase (ADH) and aldehyde dehydrogenase activities were remarkably suppressed in the liver of LEC rat, compared with Wistar rats. In the present study, we further investigated ethanol metabolism in the non-ADH pathway and what caused the decrease of liver ADH activity in LEC rats. Blood ethanol concentration 5 hr after intraperitoneal administration of ethanol in LEC rats was higher than in the Wistar rats, indicating that ethanol oxidation was impaired in LEC rats. The expression of liver cytochrome P-450IIE1 in the LEC rat was as much as that in Wistar rats. Regarding decreased ADH activity in the liver of LEC rats, we examined an alternating purine-pyrimidine (CA) repeat-length polymorphism in the first intron of a class I ADH gene that would play a role in altering ADH activity. A polymerase chain reaction method was used to amplify the CA repeat in the first intron of this class I ADH gene, a nine CA repeat insertion and a point mutation were detected in LEC rats. These results suggest that this alternating sequence would modify transcription of the class I ADH gene in LEC rats. Thus, LEC rats have abnormal ethanol metabolism in the ADH pathway.

Alcohol Dehydrogenase↗
PubMed1996

Detection of activity in the conditioned medium of ethanol-treated HepG2 cells which stimulates collagen synthesis in IMR-90 cells.

Hepatic fibrosis often occurs in alcoholic liver diseases without accompanying tissue necrosis or inflammation. However, the precise mechanism of this fibrosis has not been fully clarified. In the present study, using the hepatoblastoma cell line HepG2 as a model for hepatocytes, we identified a factor that stimulates collagen synthesis of fibroblasts in a conditioned medium of HepG2 cells after treatment with ethanol. Type 1 procollagen peptide (PIC) in a culture of human fibroblast IMR-90 markedly increased after incubation with the conditioned medium of ethanol-treated HepG2 cells. The stimulating activity on the production of PIC by IMR-90 remained after the dialysis and evaporation of the conditioned medium of HepG2 cells, indicating this factor was not as volatile from low molecular substances such as acetaldehyde, acetate, or lactate. The activity of this factor diminished with heat or trypsin treatment. A gel chromatographic analysis disclosed that the molecular weight of this factor was approximately 8000 Da. These results suggest that a polypeptide factor secreted from HepG2 cells by treatment with ethanol stimulates collagen synthesis of fibroblasts.

Carcinoma, Hepatocellular↗
PubMed1996

Tumor necrosis factor and interferon-gamma augment anticolon antibody- dependent cellular cytotoxicity in ulcerative colitis.

The effect of tumor necrosis factor (TNF) and interferon (IFN)-gamma on antibody-dependent cellular cytotoxicity (ADCC) in patients with ulcerative colitis (UC) was investigated. ADCC activity was measured by the 51Cr release assay, using peripheral blood mononuclear cells of healthy subjects as effector cells and RPMI 4788 cells derived from human colon cancer as target cells. ADCC activity under sera from healty subjects remained low whether or not the effector cells were pretreated with TNF (100 U/ml, 16h). Under sera from UC patients, ADCC activity of 13.9%, compared to 9.6% when pretreatment was deleted. The effect of IFN pretreatment (100 U/ml, 16h) was also examined under sera from UC patients; in that experiment activity rose to 26.8%, in comparison to a 10.7% when IFN-gamma pretreatment was deleted. Finally, when the effector cells were pretreated with both TNF and IFN-gamma (100 U/ml of each, 16h) the ADCC activity under sera from UC patients was higher than when either TNF or IFN-gamma were used alone. These results suggest that TNF and IFN-gamma, by increasing ADCC activity in UC lesions, are involved in cell injury in the colonic epithelium. IFN-gamma appears to increase ADCC activity by increasing the number of high affinity monocyte Fc gamma RI receptors, while TNF increases ADCC activity by a different mechanism.

Adjuvants, Immunologic↗