Search PubMed⌕ Search

Biomedical subjects

Y Shiratori

Publications and source records attributed to Y Shiratori.

At least 163 records · Page 9Linked to original sources
PubMed1996

Role of macrophages in regeneration of liver.

In an attempt to clarify the role of macrophages and their mediators during regeneration of the liver, the difference of liver regeneration among C3H/HeN (LPS-responsive strain) and C3H/HeJ (LPS-resistant strain) mice was investigated. After a 67% partial hepatectomy, an increase in the weight of regenerating liver was significantly delayed in the C3H/HeJ mice, as compared with C3H/HeN mice. The number of hepatocytes labeled with antibody against PCNA reached maximum levels 48 hr after partial hepatectomy, but the PCNA labeling index in C3H/HeJ mice was 20% less than that for C3H/HeN mice. In addition, TNF-alpha activities in serum were enhanced shortly after partial hepatectomy in C3H/HeN strain mice, but were not increased in C3H/HeJ strain mice. Serum IL-6 levels were markedly enhanced in both C3H/HeN and C3H/HeJ mice, but a bimodial peak (14 and 48 hr after partial hepatectomy) was demonstrated in C3H/HeN mice, in contrast to a single peak (at 24 hr) in C3H/HeJ mice. Suppression of Kupffer cells by previous administration of gadolinium chloride in C3H/HeN mice reduced the increase in both serum TNF-alpha and IL-6 concentrations, reduced PCNA labeling index of hepatocytes by 20%, and disturbed the regeneration of the liver. Previous administration of antibody against TNF-alpha reduced the PCNA labeling index of hepatocytes by 20% after partial hepatectomy in C3H/HeN strain mice. These results suggest that LPS-responsive macrophages in the liver and their mediators, especially TNF-alpha, could partly play a role in liver regeneration.

Animals↗
PubMed1996

Analysis of K-ras gene mutation in hyperplastic duct cells of the pancreas without pancreatic disease.

BACKGROUND & AIMS: We and others have previously shown that the mutation of K-ras codon 12 was found in the majority of pancreatic adenocarcinomas. The mutation has also been identified in the pancreatic duct with mucous cell hyperplasia in association with chronic pancreatitis. Ductal hyperplasia is also frequently found in the pancreas free from pancreatic carcinoma or chronic pancreatitis. The aim of this study was to assess the incidence and types of mutations in hyperplastic foci in these cases. METHODS: The nucleotide sequence of the K-ras gene at codon 12 of the DNA extracted from microdissected hyperplastic epithelium of the pancreatic duct obtained at autopsy in patients without pancreatic adenocarcinoma or chronic pancreatitis was analyzed. RESULTS: Of 38 patients with 79 hyperplastic foci, 12 patients (with 19 hyperplastic foci) had mutations. None of the 16 normal ducts in 12 specimens had this mutation. The nucleotide sequence of the codon in 53% of ductal hyperplastic foci was TGT or AGT, both of which were not found in 30 cases of adenocarcinoma. CONCLUSIONS: These results suggest that the ras gene mutation occurs frequently in multifocal hyperplastic foci of pancreatic duct and that the mutations may not have direct relevance to the carcinogenesis of pancreatic cancer.

Adult↗
PubMed1996

Tumor-specific gene expression in carcinoembryonic antigen--producing gastric cancer cells using adenovirus vectors.

BACKGROUND & AIMS: An increase of carcinoembryonic antigen (CEA) expression is noted in about 40% of patients with gastric cancer. Adenovirus-mediated gene therapy using the CEA promoter was investigated as a way to specifically target human CEA-producing gastric tumors. METHODS: Recombinant adenovirus vectors carrying a CEA promoter linked to the lacZ gene (AdCEA lacZ) or the cytosine deaminase gene (AdCEA-CD) were constructed. After infection with these vectors, CEA-producing (MKN45 and MKN28) and non-CEA-producing (MKN1) gastric cancer cells were analyzed for transgene expression and sensitivity to 5-fluorocytosine. RESULTS: The lacZ gene was expressed selectively in CEA-producing AdCEA-lacZ-infected cells in vitro and in vivo. Transduction of the vector containing the CEA-regulated cytosine deaminase gene (AdCEA-CD) resulted in extraordinary sensitivity of MKN45 and MKN28 cells to 5-fluorocytosine. This effect was not observed in MKN1 cells. Moreover, AdCEA-CD-infected MKN45 cells showed a profound in vitro neighbor cell killing effect in the presence of 5-fluorocytosine. This effect was attributed to the diffusion of 5-fluorouracil, resulting from conversion of 5-fluorocytosine to 5-fluorouracil by the cytosine deaminase-expressing cells. CONCLUSIONS: The results of this study suggest that use of a CEA promoter in an adenovirus vector could confer selective expression of the cytosine deaminase gene in CEA-producing gastric cancer cells, rendering the transduced cells susceptible to 5 fluorocytosine. This system may be useful in gene therapy that targets CEA-producing gastric carcinomas.

Adenoviridae↗
PubMed1996

High incidence of ADH2*1/ALDH2*1 genes among Japanese alcohol dependents and patients with alcoholic liver disease.

In an attempt to clarify the genetic factors in alcoholism among the Japanese, polymorphism of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) genes has been investigated. Genetic polymorphism of ADH2/ALDH2 in 66 cases of normal subjects, 90 cases of alcohol dependent, and 31 patients with alcoholic liver disease among Japanese has been analyzed using a polymerase chain reaction assay followed by a direct sequencing method, because ethanol is mainly catabolized by ADH and ALDH and less by cytochrome P450IIE1 and catalase. The incidence of both ADH2*1/*1 and ALDH2*1/*1 was significantly higher in patients with alcohol dependence and in patients with alcoholic liver disease when compared with that in control subjects. In addition, the incidence of ALDH2*1/*2 and ALDH2*2/*2 was significantly reduced in alcoholics compared with control subjects. Genetic polymorphism of ADH2/ALDH2 in patients with alcoholic liver disease was not different from that of alcohol dependents. According to these results, not only ALDH2 gene, often claimed to be responsible for alcohol dependence among Japanese, but also ADH2 gene polymorphism, which modulates the metabolism of ethanol, play important roles in habitual alcohol intake behavior in Japanese patients and in some patients leads to alcoholic liver diseases.

Adult↗
PubMed1996

Cytokine-induced neutrophil chemoattractant release from hepatocytes is modulated by Kupffer cells.

To clarify the role of intercellular communication in the liver during accumulation of neutrophils, the release of cytokine-induced neutrophil chemoattractant (CINC) (interleukin-8 [IL-8] related protein in rodents) by hepatocytes was investigated in the presence of Kupffer cell-conditioned medium in vitro. Kupffer cells were prepared by perfusion of rat liver with collagenase followed by centrifugation on a metrizamide gradient and were cultured in the presence or absence of lipopolysacharide (LPS). The conditioned medium was collected after 24 hours, and rat hepatocytes were cultured in the presence or absence of Kupffer cell-conditioned medium. An amount of CINC in the culture supernatant was measured by western blotting analysis and enzyme-linked immunosorbent assay (ELISA), and expression of its messenger RNA (mRNA) was assessed by the polymerase chain reaction. LPS-stimulated Kupffer cell-conditioned medium enhanced an expression of CINC mRNA in hepatocytes and increased the production of CINC by hepatocytes. Enhanced production of CINC was not shown when the Kupffer cell-conditioned medium was pretreated with heat (56 degrees C, 30 minutes). The production of CINC by hepatocytes in the presence of the LPS-stimulated Kupffer cell-conditioned medium was reduced by an antibody against interleukin 1 beta (IL-1 beta), but not by antibodies against tumor necrosis factor alpha (TNF-alpha) or LPS. These results suggest that production of CINC by hepatocytes could be regulated by IL-1 beta released from Kupffer cells, leading to neutrophil accumulation during liver injury, because this protein is a strong chemoattractant for neutrophils.

Animals↗
PubMed1996

Quantitation of alpha-fetoprotein and albumin messenger RNA in human hepatocellular carcinoma.

To analyze gene expression of alpha-fetoprotein (AFP) and albumin in hepatocellular carcinoma (HCC), messenger RNAs (mRNAs) of these proteins in six human hepatoma cell lines and in 30 cases of HCC were quantitatively analyzed by competitive reverse transcription (RT) followed by polymerase chain reaction (PCR). The transcriptional levels of both AFP and albumin genes in HepG2 and Huh 7 cell lines were 10(10) copies/microgram RNA, in contrast to approximately 10(5) copies/microgram RNA in HLE and HLF cell lines. AFP and albumin mRNA levels in three normal livers were 10(5) and 10(10) transcripts/microgram RNA, respectively. In 30 cases with HCC AFP mRNA level in neoplasm was 10 to 10(5)-fold enhanced as compared with that of nonneoplastic portion, and correlated with serum AFP level and tumor size (P < .01). In contrast, albumin mRNA level was not reduced in the neoplasms presenting enhanced AFP mRNA levels, indicating that AFP and albumin gene expression in situ is not necessarily mutually exclusive. Prospective analysis revealed that an increased serum AFP was shown at the time of recurrence among patients with enhanced AFP mRNA levels in neoplasm only, indicating that AFP mRNA levels in neoplasm could be a clinically predictable tool.

Aged↗
PubMed1996

Endoscopic papillary balloon dilation in cirrhotic patients: removal of common bile duct stones without sphincterotomy.

BACKGROUND AND STUDY AIMS: Endoscopic papillary balloon dilation (EPBD) is a less invasive alternative to endoscopic sphincterotomy (EST). This study reviews a series of cirrhotic patients with bile duct stones who were treated with EPBD. PATIENTS AND METHODS: EPBD was used to remove common bile duct stones in nine cirrhotic patients (one in Child-Pugh grade A, four in grade B, and four in grade C). After the papilla was dilated with balloon-tipped catheter, the stones were removed with a retrieval basket catheter or a retrieval balloon, or both. Mechanical lithotripsy was required in two patients with stones of more than 1 cm in diameter. RESULTS: Clearance of the common bile duct was achieved in all patients without any serious complications such as hemorrhage or perforation. CONCLUSIONS: These results suggest that EPBD is a safe and effective technique for the treatment of common bile duct stones in patients with liver cirrhosis.

Aged↗
PubMed1996

Pore formation on proliferating yeast Saccharomyces cerevisiae cell buds by HM-1 killer toxin.

The cytocidal effect of HM-1 produced by Hansenula mrakii on yeast Saccharomyces cerevisiae cells was studied. The HM-1 strongly inhibited the growth of S. cerevisiae cells at a low concentration (IC50: 2.1 x 10(-8) M) by reducing the number of viable cells. The killer action of HM-1 was most efficient when cells were actively proliferating. Cells in a resting state were resistant, but they became HM-1-sensitive after about 90 min of culturing at 30 degrees C, concomitantly with the increment of budding index. In association with the reduction of viable cell number, ultraviolet light-absorbing cellular components were discharged from sensitive cells. HM-1 molecules appear to bind to susceptible cells rather loosely since cells incubated with HM-1 were able to proliferate after having been washed. By phase-contrast light microscopy and scanning electron microscopy, discharge of cell material was observed at the budding portions of HM-1-treated cells. Addition of sorbitol to make the culture medium isotonic partially reduced the cell death induced by HM-1. These results suggest that HM-1 acts on the budding region of proliferating yeast cells, resulting in pore formation, leakage of cell material and eventual cell death.

Cell Division↗
PubMed1996

Real-time monitoring of HCV-RNA by single tube assay kit and potential importance for predicting virological sustained response in patients with chronic hepatitis C.

In an attempt to predict virological sustained responders among patients with chronic hepatitis C after interferon therapy, HCV-RNA in serum was measured by a one tube RT-PCR assay kit using the RNA corresponding to 5 microL serum (standard assay) or 300 microL serum (enhanced-sensitivity assay). Dilution analysis revealed that sensitivity of the 'enhanced-sensitivity assay' increased by 10-100-fold when compared with a 'standard assay'. Using these assays, prospective study of interferon therapy on 38 HCV-RNA seropositive cases with chronic hepatitis (total amount 702 MU; duration of treatment 5-6 months) was performed. At the end of treatment, six were still positive and 32 became negative by the "standard assay', whereas an additional eight cases became positive (total 14 cases positive; the remaining 24 cases negative) by the 'enhanced-sensitivity assay'. Hepatitis C viral RNA state at the end of treatment remained the same 6 months later in 23 cases (61%) by a 'standard assay' and in 31 (82%) by the 'enhanced-sensitivity assay'. Of importance was that all patients (14 cases) demonstrating HCV-RNA in serum at the end of therapy, even by the "enhanced-sensitivity assay', did not show the disappearance of HCV-RNA in serum despite the long follow up. From these results, in order to improve our treatment efficacy, we should try to modify our treatment protocol to the extent that at least HCV-RNA becomes undetectable. That can be only feasible during treatment by real-time monitoring of HCV-RNA.

Adult↗
PubMed1996

[Development of a detection system for Helicobacter pylori DNA in gastric juice].

A rapid and sensitive PCR-based microwell plate assay (PCR-MWP) system to detect the 16 S ribosome RNA gene of Helicobacter pylori was developed. Analytical sensitivity, evaluated with purified recombinant plasmid DNA and genomic DNA of H. pylori, was one copy of DNA per PCR. Specificity was validated with a panel of DNA from 75 kinds of microorganisms including Helicobacter showed weak positives, when 1 pg of DNA was input. Other microorganisms gave negative signals even when 100 pg of DNA was used for PCR. When compared with a Nested-PCR system to detect the urease A-subunit gene performed by a commercial reference laboratory, the results obtained (sensitivity 93.3% and specificity 73.3%) was almost equivalent. The PCR-MWP was rapid and easy for the detection of H. pylori DNA in gastric juice specimen.

DNA, Bacterial↗
PubMed1996

[Percutaneous ethanol injection therapy for small hepatocellular carcinoma].

Hepatocellular carcinoma is different from other solid tumors. Because of concomitant cirrhosis or multiple lesions, most hepatocellular carcinoma is unresectable. Still worse, hepatocellular carcinoma frequently recurs after surgical resection; the 5-year cumulative recurrence rate is 70-90% even after curative hepatectomy. The situation is similar in small hepatocellular carcinoma 2 cm or less in diameter. Thus, non-surgical treatment plays an important role. At present, we think that percutaneous ethanol injection therapy (PEIT) is best for the treatment of hepatocellular carcinoma because of its local curativity, minimal adverse effect on liver function, and the easy feasibility of repeated treatment for recurrence. We have recently treated about 85% of hepatocellular carcinoma cases by PEIT and have achieved satisfactory long-term results. Here we describe our results in PEIT for small hepatocellular carcinoma. By the end of December 1995, we performed PEIT on 410 patients with hepatocellular carcinoma. Among them, 140 patients were diagnosed as having small hepatocellular carcinoma 2 cm or less in diameter. The 1-, 3-, 5-, 7-, and 10-year survival rates of the 140 patients were 93%, 73%, 55%, 51%, and 32%, respectively. Furthermore, in 83 patients who had a single, small hepatocellular carcinoma 2 cm or less in diameter, the 1-, 3-, 5-, 7-, and 10-year survival rates were 92%, 82%, 72%, 66%, and 66%, respectively. Thus PEIT achieved satisfactory long-term survival rates in the treatment of small hepatocellular carcinoma.

Adult↗
PubMed1995

Stimulation of CTP:phosphocholine cytidylyltransferase by free cholesterol loading of macrophages involves signaling through protein dephosphorylation.

Free cholesterol-loaded macrophages in atheromata synthesize excess phosphatidylcholine (PC), which may be an important adaptive response to the excess free cholesterol (FC) load. We have recently shown that FC loading of macrophages leads to 2-4-fold increases in PC mass and biosynthesis and to the post-translational activation of the membrane-bound form of CTP:phosphocholine cytidylyltransferase (CT), a key enzyme in PC biosynthesis. Herein, we explore further the mechanism of CT activation in FC-loaded macrophages. First, enrichment of membranes from control macrophages with FC in vitro did not increase CT activity, and PC biosynthesis in vivo is up-regulated by FC loading even when CT and FC appear to be mostly in different intracellular sites. These data imply that FC activates membrane-bound CT by a signaling mechanism. That the proposed signaling mechanism involves structural changes in the CT protein was suggested by data showing that two different antibodies against synthetic CT peptides showed increased recognition of membrane-bound CT from FC-loaded cells despite no increase in CT protein. Since CT is phosphorylated, two-dimensional maps of peptides from 32P-labeled control and FC-loaded macrophages were compared: six peptide spots from membrane-bound CT, but none from soluble CT, were dephosphorylated in the FC-loaded cells. Furthermore, incubation of FC-loaded macrophages with the phosphatase inhibitor, calyculin A, blocked increases in both PC biosynthesis and antipeptide-antibody recognition of CT. Last, treatment of membranes from control macrophages with lambda phage protein phosphatase in vitro increased both CT activity (2-fold) and antipeptide-antibody recognition of CT; soluble CT activity and antibody recognition were not substantially affected by phosphatase treatment. In summary, FC loading of macrophages leads to the partial dephosphorylation of membrane-bound CT, and possibly other cellular proteins, which appears to be important in CT activation. This novel regulatory action of FC may allow macrophages to adapt to FC loading in atheromata.

Animals↗
PubMed1995

Role of tissue factor in disseminated intravascular coagulation.

We examined plasma antigen levels of tissue factor (TF) in 95 cases of disseminated intravascular coagulation (DIC), to investigate the role of TF in DIC. A significant elevation of plasma antigen levels of TF was observed in cases of DIC associated with cancer. However, no such significant elevation was observed in cases of DIC associated with acute promyelocytic leukemia (APL), acute leukemia except APL, blastic crisis of chronic myelogenous leukemia, non-Hodgkin lymphoma (NHL), sepsis or fulminant hepatitis. No significant elevation of TF was observed in patients without DIC, except 4 cases of cancer who developed DIC thereafter. Plasma antigen levels of TF were higher in both cases of DIC with renal failure and chronic renal failure without DIC than its levels in those without renal failure. Therefore, plasma antigen levels of TF in DIC patients with renal failure were considered to be carefully estimated. The levels of TF were decreased with the clinical improvement in some cases of DIC but were further increased or remained at high levels in patients who showed no improvement of DIC. Thus, plasma antigen levels of TF is an important marker to predict the development and/or prognosis of DIC, especially in patients with cancer.

Adult↗
PubMed1995

Increased nitric oxide in the exhaled air of patients with decompensated liver cirrhosis.

OBJECTIVE: To determine if nitric oxide output in exhaled air is increased in patients with liver cirrhosis. DESIGN: Cross-sectional study. SETTING: A university hospital. PATIENTS: 50 patients with liver cirrhosis, 6 patients with chronic hepatitis, and 15 healthy controls. MEASUREMENTS: Nitric oxide in exhaled air was measured using a chemiluminescence analyzer. Cardiac index was determined using echocardiography. RESULTS: Patients with decompensated liver cirrhosis had higher levels of exhaled nitric oxide output (Child C patients, 190 +/- 11 nL/min per m2 body surface area) than controls (97 +/- 8 nL/min per m2 body surface area; P < 0.001), whereas patients with compensated liver cirrhosis or chronic hepatitis had levels of nitric oxide output similar to those found in controls. Cardiac index was greater in patients with liver cirrhosis (Child C patients, 4.3 +/- 0.3 L/min per m2 body surface area) than in controls (2.9 +/- 0.2 L/min per m2 body surface area; P < 0.001). Cardiac index correlated with nitric oxide levels (r = 0.621; P < 0.001). CONCLUSIONS: Increased nitric oxide output in exhaled air is associated with systemic circulatory disturbances in patients with liver cirrhosis.

Aged↗
PubMed1995

Sensitive assay for detection of hepatocellular carcinoma associated gene transcription (alpha-fetoprotein mRNA) in blood.

The sensitivity of RT-PCR and nested RT-PCR for detection of circulating hepatocellular carcinoma was assessed by demonstrating the tumor cell-associated gene transcription, alpha-fetoprotein mRNA, in the nuclear cells of peripheral blood. When HepG2 cells were mixed in blood, 100-1000 tumor cells/5ml of blood could be detected by RT-PCR, in contrast to 1-10 tumor cells/5ml of blood by nested RT-PCR. In addition, 2 x 10(4) copies of AFP mRNA were found in one HepG2 cell when analyzed by the quantitative nested RT-PCR assay. Thus, the nested RT-PCR assay could provide a useful tool for detecting a tiny amount of circulating tumor cells in patients with hepatocellular carcinoma presenting extra-hepatic metastasis.

Base Sequence↗