Biomedical subjects

F Imazeki

Publications and source records attributed to F Imazeki.

At least 37 records · Page 2Linked to original sources

PubMed1999

Spontaneous negativation of serum hepatitis C virus RNA is a rare event in type C chronic liver diseases: analysis of HCV RNA in 320 patients who were followed for more than 3 years.

BACKGROUND/AIMS: The natural course of hepatitis C virus (HCV) replication in type C liver diseases has not yet been elucidated. The aim of the study was to investigate the spontaneous outcome of the viremia by examining the changes in HCV RNA in patients with chronic type C liver diseases. METHODS: Among patients who visited our liver clinic between June 1981 and December 1993, 320 patients with chronic type C liver diseases were followed for at least 3 years and had no history of interferon treatment. HCV RNA was examined by a highly specific reverse transcription-polymerase chain reaction method in paired serum samples obtained from these patients at the beginning and end of follow-up. RESULTS: Among the 320 cases, HCV RNA was seropositive in 310 (97%) cases at the beginning of follow-up. Of these 310, HCV RNA remained seropositive in 304 (98%) and became seronegative in six (2%) cases by the end of follow-up. All of these six patients had liver cancer. HCV RNA became seronegative after the patients entered the state of liver failure because of the development of tumors or portal thrombosis. The remaining 10 cases who were seronegative for HCV RNA at the beginning were seropositive at the end of follow-up. Among the 320 cases, serum alanine aminotransferase normalized and remained normal for more than 12 months until the end of follow-up in 11 cases (0.6%/year/case), but none became negative for HCV RNA. CONCLUSIONS: Thus, during the natural course of chronic HCV infection, spontaneous negativation of serum HCV RNA seems extremely rare, at least in patients with chronic active hepatitis or cirrhosis of the liver, and may occur primarily at the terminal stage when tumors cause liver failure.

Aged↗

PubMed1999

Quantitative evaluation of telomerase activity in small liver tumors: analysis of ultrasonography-guided liver biopsy specimens.

BACKGROUND/AIMS: Telomerase activity which restores the length of telomere repeat arrays is frequently detectable in various malignancies, including hepatocellular carcinoma. The aim of this study was to determine the diagnostic usefulness of the quantitative measurement of telomerase activity in small liver tumors, which has not yet been established. METHODS: Fifty-eight liver specimens from tumorous and non-tumorous portions of 29 small liver tumors equal to or less than 3.0 cm were obtained by ultrasonography-guided liver biopsy, and of these, 25 were diagnosed as hepatocellular carcinoma and four as adenomatous hyperplasia. The telomerase activities in these specimens and control specimens were examined quantitatively by telomeric repeat amplification protocol with standard control. RESULTS: The mean telomerase activity in cirrhosis without liver tumor was 0.4+/-0.6 (+/-S.D.) arbitrary units (AU) and that in 29 non-tumorous parts of the tumors was 4.5+/-7.4 AU. The mean telomerase activity in 13 tumors equal to or less than 2 cm in diameter was 77.1+/-133.7 AU and that in 16 tumors more than 2 cm was 152.7+/-215.2 AU. The mean telomerase activity in the 4 adenomatous hyperplasias was 5.5+/-4.5 AU; those of hepatocellular carcinoma with Edmondson-Steiner classification I, II, III and IV were 49.6+/-47.4 (n = 10), 240.1+/-273.6 (n = 9), 119.2+/-174.6 (n = 4) and 144.6+/-80.2 (n = 2) AU, respectively. CONCLUSIONS: The telomerase activity was significantly higher in hepatocellular carcinoma compared to adenomatous hyperplasia and non-neoplastic tissue, indicating that the quantitation of telomerase activity would be useful for the diagnosis of small hepatocellular carcinoma.

Adenoma↗

PubMed1999

How soon can a virological sustained response be determined after withdrawal of interferon therapy in chronic hepatitis C? Tokyo-Chiba Hepatitis Research Group.

Hepatitis C virus (HCV)-RNA status and alanine aminotransferase (ALT) levels determined shortly after interferon (IFN) therapy in patients with chronic hepatitis C do not predict long-term response. To determine the virological sustained response after the completion of IFN therapy, HCV-RNA was measured at the end of treatment and at 3-4 months and 12 months after the completion of therapy in 537 patients with chronic hepatitis C. In 347 patients, HCV-RNA was not detected by polymerase chain reaction (PCR) at the completion of therapy and 175 of these patients (50%) were still PCR negative 12 months later. In contrast, of the 180 patients who were HCV-RNA negative at 3-4 months after completion of therapy, 99% remained negative at 12 months. Normal ALT levels were found in 80, 93 and 95% of patients who were negative for HCV-RNA either at the end of treatment or at 3-4 months and 12 months after the completion of therapy, respectively. Of patients who were HCV-RNA positive, 30, 15 and 20% were found to have normal ALT levels at the same respective time points. To determine a sustained virological response shortly after the completion of therapy, serum HCV-RNA was serially examined in 66 patients negative for HCV-RNA at the end of therapy. Of 31 patients who relapsed, HCV-RNA reappeared in 33, 80, 97 and 100% of patients by 1, 2, 4 and 8 weeks after the completion of therapy. In conclusion, a sustained virological response could be determined with 97 and 99% certainty at 4 weeks and at 3-4 months after the completion of therapy, respectively.

Adult↗

PubMed1999

Detection of mutations in the enhancer 2/core promoter region of hepatitis B virus in patients with chronic hepatitis B virus infection: comparison with mutations in precore and core regions in relation to clinical status.

To investigate the meaning of the mutations in the enhancer 2/core promoter (Enh2/CP) region of hepatitis B virus (HBV) during the chronic HBV infection, mutations were examined in the Enh2/ CP region (carboxyl half of X region) and their correlation with mutations in the precore and core regions in relation to the presence of chronic liver disease. The entire nucleotide sequences of the Enh2/CP region were determined by direct sequencing of the amplified products derived from 30 cases with chronic HBV infection. The results were compared to the mutations in the precore and core regions. In the Enh2/CP region, 91 generally scattered nucleotide substitutions were detected. There were 11 substitutions in the 10 asymptomatic healthy carriers (mean, 1.1/case) and 80 in the 20 chronic liver disease patients (4.0/case). The most frequent substitutions from A to T at nucleotide 1764 and from G to A at nucleotide 1766 were seen in none of the 10 asymptomatic carriers and in 14 (70%) of the 20 chronic liver disease patients. Comparisons of mutations in the precore and core regions revealed that 14 of 16 patients with mutations in the core region had the mutations in the Enh2/CP region and/or a precore stop codon mutation. These data suggest that mutations in the Enh2/CP and precore regions may affect the expression of the core and HBeAg peptides and might be involved in the pathogenesis of chronic liver disease.

Adolescent↗

PubMed1999

[Molecular mechanism of hepatocarcinogenesis].

Hepatocellular carcinoma (HCC) in Japan is closely associated with the chronic liver diseases of infection with the hepatitis B or C viruses. Analysis of HCC tissues frequently detects loss of heterozygosity at chromosomes 1p, 4, 6q, 8p, 10q, 13q, 16q, 17p, and many genomic and epigenomic abnormalities have been found in p53, beta-catenin, p16CDKI, DNA mismatch repair genes, and others. However, no specific abnormal genetic or epigenetic changes for HCC have been found so far. The development of HCC has been reported in mice transgenic for the hepatitis B virus X gene or the hepatitis C virus core gene, and these viral proteins might play essential roles in hepatocarcinogenesis. Chronic hepatitis and fibrosis due to persistent viral infection might also influence the genomic instability of hepatocytes, leading to accumulation of genomic changes.

Animals↗

PubMed1998

Quantitative analysis of GBV-C RNA in liver and serum by strand-specific reverse transcription-polymerase chain reaction.

BACKGROUND/AIMS: Although GB virus C (GBV-C) is frequently detectable in patients with liver diseases, it is not known whether it actually replicates in the liver. Therefore we have quantitatively examined the strand-specific RNA of this virus. METHODS: Fourteen patients (two GBV-C RNA only seropositive, seven both GBV-C RNA and HCV RNA seropositive, and five HCV RNA only seropositive) were examined. Extracted RNAs from sera and liver specimens of these patients were serially diluted and strand-specific RNAs of GBV-C and HCV were quantitatively measured using strand-specific primers by reverse transcription-polymerase chain reaction. RESULTS: Positive-strand GBV-C RNA in serum was detected in all nine GBV-C RNA seropositive cases, and negative-strand RNA was detected in three, uncertain in three, and undetected in three. Positive-strand GBV-C RNA in the liver was detected in seven and undetected in two, while negative-strand RNA in the liver was undetected in eight and uncertain in one. On the other hand, positive-strand HCV RNA was detected in serum from all 12 HCV RNA seropositive patients and negative-strand HCV RNA was detected in one, uncertain in seven, and undetected in four. Positive-strand HCV RNA was detected in the liver from all 12 HCV RNA seropositive patients, and the presence of negative-strand HCV RNA in the liver was confirmed in 10 and uncertain in the remaining two. CONCLUSION: GBV-C is considered to be far less hepatotropic than HCV, and it is suggested that GBV-C might not be replicating in the liver.

Adult↗

PubMed1998

The two different states of hepatitis B virus DNA in asymptomatic carriers: HBe-antigen-positive versus anti-HBe-positive asymptomatic carriers.

During the course of hepatitis B virus (HBV) infection, there exists a long period of normal liver function tests with different states of HBeAg/Ab. As the state of HBV in asymptomatic carriers was not well characterized, we quantitatively and qualitatively examined HBV in both HBeAg-positive and anti-HBe-positive asymptomatic carriers. Sera from 10 HBeAg-positive and 27 anti-HBe-positive asymptomatic carriers were analyzed. The amount of HBV DNA was determined by dot-blot hybridization and polymerase chain reaction. The mutations in precore and core regions, spanning 636 nucleotides, of hepatitis B virus were examined by directly sequencing the amplified HBV DNA. HBV DNA was detected in all 10 HBeAg-positive cases, whereas it was found in only 7 of 27 (26%) anti-HBe-positive cases by the nested PCR method. The mean amount of HBV DNA in HBeAg-positive cases was 10(9.1 +/- 0.7) copies/ml, while that in anti-HBe-positive cases was 10(1.0 +/- 1.5) copies/ml. There were no missense mutations in the entire precore and core genes of HBV DNA taken from HBeAg-positive asymptomatic carriers. In contrast, many mutations (mean 9.0 +/- 3.3, range 6-14) were detected in the core gene of seven anti-HBe-positive asymptomatic carriers including two cases with increments of the mutations. Analysis of the precore region revealed three wild-type and four mutant-type (including one coexisting with wild-type) cases. These data suggest that HBV exists in quite different ways in "asymptomatic" carriers; in the HBeAg-positive phase HBV probably coexists with the host and remains as the wild type, whereas in the anti-HBe-positive phase a drastically reduced amount of HBV with many mutations remains, probably as a consequence of the long-lasting interaction with the host. Nevertheless, such small amount of virus could cause fulminant hepatic failure. It is important to make further clinical and virological investigations in order to understand the state of asymptomatic carrier.

Adult↗

PubMed1998

Expression of p53 and p21WAF1/CIP1 proteins in gastric and esophageal cancers: comparison with mutations of the p53 gene.

The p53 gene has been shown to be commonly mutated in various human cancers, and mutant p53 can act as a dominant oncogene. The intact p53 protein is also known to induce the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and is implicated in cell cycle arrest. We investigated p53 gene alterations in gastric adenocarcinoma and esophageal squamous cell carcinoma to elucidate the association of the nuclear accumulation of the p53 protein and/or p21WAF1/CIP1 protein. Abnormalities of the tumor suppressor gene p53 protein and the expression of p21WAF1/CIP1 protein were analyzed by immunohistochemical techniques in 32 cases of gastric adenocarcinoma and 15 cases of esophageal squamous cell carcinoma. Twenty cases of gastric cancer and five cases of esophageal cancer were also analyzed for p53 gene mutation by polymerase chain reaction and direct nucleotide sequencing. Overexpression of p53 protein was found in 13/32 (41%) of gastric cancers and 5/15 (33%) of esophageal cancers. We found immunodetectable p53 in 10/14 cases with mutations and in none of 11 cases without mutations in gastric and esophageal cancers. Hence, immunohistochemical and genetic analyses gave concordant results in 84% of 25 cases, revealing a good correlation between immunostaining of p53 and missense mutation of the p53 gene. p53 immunostaining was not observed in cases with frameshift or splicing mutation. The expression of p21WAF1/CIP1 protein was found in 9/32 (29%) of gastric cancers and 4/15 (27%) of esophageal cancers and in 2/14 (14%) cases with alteration of the p53 gene and in 5/11 (45%) without. These results suggest that abnormalities of p53 may be closely associated with the pathogenesis of gastric adenocarcinoma and esophageal squamous cell carcinoma and that the immunoreactivity of p53 protein is a general indicator of the tumors with altered p53 function. The expression of p21WAF1/CIP1 protein was suppressed in the neoplastic tissues with and without p53 gene alteration.

Adenocarcinoma↗

PubMed1998

Etiologic considerations of fulminant non-A, non-B viral hepatitis in Japan: analyses by nucleic acid amplification method.

The etiology of fulminant non-A, non-B hepatitis has remained unclear, even after the identification of hepatitis C and E viruses. To study the possible involvement of hepatitis B, C, D, and E virus infections, viral genomes were amplified by a sensitive polymerase chain reaction method in sera and liver tissues obtained from 20 patients serologically diagnosed with non-A, non-B fulminant hepatitis (n = 14), acute hepatitis severe type (n = 2), and ordinary acute hepatitis (n = 4). Hepatitis C or E virus RNA could not be detected in sera obtained at admission from these patients. Hepatitis B virus DNA was detected in sera from 3 patients with fulminant hepatitis and in liver from 9 patients with fulminant hepatitis or acute hepatitis severe type. These results suggest that HCV might not be involved in fulminant non-A, non-B hepatitis, and HBV might be related to some of the serologic "non-A, non-B" viral hepatitis cases in Japan.

Adult↗

PubMed1997

Detection of GBV-C RNA in patients with non-A-E fulminant hepatitis by reverse-transcription polymerase chain reaction.

GBV-C might be a causative agent of fulminant hepatitis of unknown etiology. Fulminant hepatitis is an indication for liver transplantation. However, in Japan, because of the legal difficulties associated with cadaveric donation, patients with fulminant hepatitis are still treated by plasmapheresis and multiple transfusions of fresh frozen plasma. So, the possibility that GBV-C might be transmitted by transfusions after the onset of fulminant hepatitis is real. Therefore, we have examined the possible role of GBV-C in non-A-E fulminant hepatitis. Nine patients with non-A-E fulminant hepatitis and one with non-A-E late onset hepatic failure were examined. Sera were obtained from the patients at admission before any blood or blood products were given, and again after transfusions. GBV-C RNA was detected by nested reverse transcription polymerase chain reaction with primers based on the reported sequence. GBV-C RNA was negative in all 10 pretransfusion patients with non-A-E fulminant hepatitis or late onset hepatic failure. Then, fresh frozen plasma was transfused to these patients, and four of them became seropositive. GBV-C is unlikely to be a major etiologic agent for non-A-E fulminant hepatitis in Japan.

Adult↗

PubMed1997

GB virus-C RNA in Japanese patients with hepatocellular carcinoma and cirrhosis.

BACKGROUND/AIMS: The involvement of non-B, non-C virus in the incidence of hepatocellular carcinoma (HCC) is not yet known. We have therefore examined the occurrence of GBV-C RNA in such patients. METHODS: One hundred and eleven patients diagnosed as having HCC and 67 patients with cirrhosis without HCC were examined for the prevalence of GBV-C RNA by nested reverse transcription polymerase chain reaction with primers located at the helicase region. Sera were obtained and kept at -20 degrees C until analysis. RESULTS: GBV-C RNA was positive in 11/111 (9.9%) cases with HCC, in 10/74 (13.5%) anti-HCV positive cases, in 1/25 (4%) HBsAg positive cases, and in 0/8 (0%) anti-HCV and HBsAg negative cases. GBV-C RNA was also positive in 7/67 (10.4%) cases with cirrhosis, in only 1/18 (5.6%) anti-HCV and HBsAg negative cases, in 4/33 (12.1%) anti-HCV positive, and in 2/14 (14.3%) HBsAg positive cases. The clinical background of patients with anti-HCV positive HCC who were also positive for GBV-C RNA did not differ from the background of those negative for GBV-C RNA. CONCLUSIONS: GBV-C is unlikely to be a major etiologic agent of non-B, non-C chronic liver diseases and HCC in Japan.

Adult↗

PubMed1997

Telomerase activity and telomere length in hepatocellular carcinoma and chronic liver disease.

BACKGROUND & AIMS: The maintenance of the telomere to a certain length is considered to be vital for cellular immortality. Recently, the presence of telomerase, an enzyme that elongates telomere length, was reported in various malignancies. The aim of this study was to characterize telomerase activity and telomere length in hepatocellular carcinoma and chronic liver diseases to facilitate better understanding and more accurate diagnosis of hepatocellular carcinoma. METHODS: In tumorous and nontumorous tissues from 26 hepatocellular carcinomas and from 20 liver tissues without overt hepatocellular carcinoma, telomerase activity was examined by telomeric repeat amplification protocol and telomere length was detected by Southern blot hybridization method. RESULTS: Telomerase activity was detected in 22 of 26 (85%) hepatocellular carcinoma specimens. In contrast, it was weakly detected in 4 of 46 (9%) nonneoplastic tissues. Telomere length in hepatocellular carcinoma was shorter than that of corresponding nontumorous tissue in 44% and longer in 17%. CONCLUSIONS: The presence of telomerase activity was confirmed in a majority of cases with hepatocellular carcinoma, and alteration of telomere length from nonneoplastic tissue was observed in approximately two thirds of hepatocellular carcinomas. Therefore, these markers might be good indicators for the diagnosis of hepatocellular carcinoma.

Adult↗

PubMed1997

Predictors of the efficacy of interferon therapy in chronic hepatitis C virus infection. Tokyo-Chiba Hepatitis Research Group.

BACKGROUND & AIMS: The relative role of virus load and hepatitis C virus (HCV) subtype as predictor of the efficacy of interferon (IFN) therapy is still in dispute. To resolve this issue, a multicenter, randomized, prospective study of 272 patients with chronic hepatitis C but without cirrhosis was conducted. METHODS: The patients were randomly assigned to two different dose groups: 6 million units (MU) or 9 MU IFN three times a week for 6 months. Serum HCV RNA levels and HCV subtypes were determined. RESULTS: HCV RNA negativity rate at the completion of treatment with 9 MU IFN was higher than that with 6 MU (75% vs. 44%; P < 0.05). Virus eradication at 12 months after completion of treatment was higher in the 9 MU group than in the 6 MU group (36% vs. 25%; P < 0.05), especially in patients who had an intermediate virus load (10(4)-10(5) copies/mL by Amplicor monitor assay) (52% vs. 19%; P = 0.029). Virus eradication rate in patients with serotype 2 was higher than in those with serotype 1 for both regimens (6 MU, 53% vs. 15%; 9 MU, 76% vs. 29%; each P < 0.05). CONCLUSIONS: This prospective study showed that virus load, HCV serotype, and IFN dose are important predictors of the virological response to IFN therapy but virus load is the most important factor influencing the efficacy of IFN.

Adult↗

PubMed1997

Frequent detection of hepatitis A viral RNA in serum during the early convalescent phase of acute hepatitis A.

The diagnosis of type A hepatitis is performed mainly by immunoglobulin M (IgM) anti-hepatitis A antibody assay, but it has not been established whether there is a correlation between changes in viremia and the clinical course of type A hepatitis. We examined hepatitis A virus (HAV) RNA in the sera from type A and non-A, non-B, non-C acute hepatitis and analyzed the relation of HAV viremia with alanine aminotransferase (ALT) and IgM-HA levels. Two hundred sera from 38 patients with type A acute hepatitis and 20 patients with non-A, non-B, non-C acute hepatitis were examined for the presence of HAV RNA. HAV RNA was detected by nested reverse transcription-polymerase chain reaction (RT-PCR) with primers located at the 5' non-translated region of HAV. HAV RNA was detected in 35 of 38 (92%) type A hepatitis patients and in 60 of 156 (38%) serum samples. In contrast, it was detected in none of 44 serum specimens from 20 non-A, non-B, non-C acute hepatitis patients. In type A hepatitis, the mean ALT level in HAV RNA positive specimens was 1,481 +/- 2,042 (range, 20-10,370) IU/L and that in HAV RNA negative specimens 186 +/- 330 (range, 8-1,698). The positivity of HAV RNA was correlated with the level of transaminase at the time of sample collection. The mean duration from the onset of symptoms to disappearance of HAV RNA was 18 +/- 14 days. The mean titer of IgM-HA in HAV RNA positive cases was 5.0 +/- 1.4, in negative cases 5.7 +/- 1.1, with no statistical difference. Our results indicate that HAV RNA in serum is detectable in the majority of type A hepatitis cases in their early convalescent phase by nested RT-PCR.

Acute Disease↗

PubMed1997

Polymorphism of alcohol-metabolizing genes affects drinking behavior and alcoholic liver disease in Japanese men.

Alcohol is known to be mainly metabolized in the liver by alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2), and cytochrome P-450IIEI. The purpose of this study was to clarify the role of polymorphism of these ethanol-metabolizing enzymes in drinking behavior and the progression of alcoholic liver disease among Japanese men. Polymorphism of the ADH2, ALDH2, and P-45IIEI genes were determined by polymerase chain reaction, followed by restriction fragment-length polymorphism analysis in 189 normal Japanese men and 26 male patients with alcoholic liver disease. Drinking behavior was estimated by self-assessment according to DSM-III-R criteria. Facial flushing was reported in 91 subjects heterozygous for ALDH2*1/*2 and in two subjects homozygous for ALDH2*2/*2, but was not found in 96 subjects homozygous for ALDH2*1/*1. In contrast, polymorphism of ADH2 and P-450IIEI did not differ between flushers and nonflushers. Although the flushers only drank a small amount of alcohol (< 20 g of ethanol/day), the nonflushers were divided into a group of moderate drinkers (20 to 80 g/day; n = 54) and a group of heavy drinkers (> 80 g/day; n = 42). A high preponderance of heterozygosity for the ADH2*1/*2 genes (20/42; 60%) and a high frequency of the ADH2*1 allele were found in heavy drinkers, compared with moderate drinkers. However, cytochrome P-45IIEI gene polymorphism was similar among the moderate and heavy drinkers. Not only a high frequency of the ALDH2*1 and ADH2*1 alleles, but also a high frequency of the P-450IIEI c2 allele was found in the patients with alcoholic liver disease. From these results, the drinking behavior of Japanese men is strongly influenced by the ALDH2*1 allele, and the level of alcohol intake is affected by the ADH2*1 allele, but not by cytochrome P-45IIEI. However, progression to alcoholic liver disease among heavy drinkers may be affected by the cytochrome P-450IIEI c2 allele.

Adult↗

PubMed1996

A transforming growth factor beta type II receptor gene mutation common in sporadic cecum cancer with microsatellite instability.

Mismatch repair genes are the responsible genes for hereditary non-polyposis colon cancer, and mutation of these genes causes replication error (RER). In several RER-positive colon cancer cell lines, mutations of repetitive sequences of transforming growth factor beta (TGF-beta) type II receptor (RII) gene have been reported. Since TGF-beta inhibits cell proliferation, loss of response to TGF-beta is an important tumor progression step. In this study, the relationship between RER status and mutation of the RII gene was analyzed in 112 cases of various types of sporadic gastrointestinal and hepatobiliary cancer (41 with gastric, 49 with colorectal, 5 with gallbladder, and 17 with hepatic cancers). RER was found in 17 cases (4 with gastric, 12 with colorectal, and 1 with gallbladder cancer), and 10 of those (3 with gastric and 7 with colorectal cancer) showed mutations of the RII gene. Of interest was that in all seven cases with colorectal cancer, tumors were located at the cecum. These data indicate that mutation of the RII gene, presumably caused by abnormality of repair gene, play an important role in carcinogenesis of sporadic gastrointestinal cancer, especially at the cecum.

Aged↗

PubMed1996

Gene expression and active virus replication in the liver after injection of duck hepatitis B virus DNA into the peripheral vein of ducklings.

BACKGROUND/AIMS: Duck hepatitis B virus is a member of the hepadnavirus family, which possesses strong hepatotropism. Duck hepatitis B virus DNA serves as a replicative template for producing biologically active virus particles after transfection into cell lines established from human hepatocellular carcinoma or into duck liver by direct injection of calcium phosphate-precipitated DNA. Our aim was to develop a new method of liver-specific gene expression after intravenous DNA delivery. METHODS/RESULTS: We inoculated duck hepatitis B virus DNA with and without cationic liposomes, Lipofectin or LipofectAMINE, as DNA carries. Two weeks after a single intravenous injection of 10 or 50 micrograms of plasmid DNA containing a head-to-tail dimer of duck hepatitis B virus DNA into 25 one-day old ducklings, duck hepatitis B virus RNA transcripts including the pregenome replicative intermediate were detected by Northern blot in the liver of eight ducks (100%) of the Lipofectin group, five ducks (63%) of the LipofectAMINE group, and three ducks (50%) of the group which received DNA without carrier. Duck hepatitis B virus RNA transcription was almost exclusively liver specific, even though the liposomes had no tissue specificity. Replicative forms of duck hepatitis B virus DNA were detected in the liver and DHBsAg was observed in the cytoplasm of the hepatocytes by immunostaining. The serum of transfected ducklings contained virus particles which were infectious in other ducklings. CONCLUSION: The efficient and liver-specific expression of inoculated DNA was due to the amplification of nucleic acids by active virus replication process under the control of hepatocyte specific regulation.

Animals↗

PubMed1996

Expression of variant CD44-messenger RNA in colorectal adenocarcinomas and adenomatous polyps in humans.

BACKGROUND & AIMS: Recent studies have shown that some variant forms of CD44, a transmembrane glycoprotein expressed on various cell surfaces, might be involved in tumor progression or tumor metastasis. The aim of this study was to analyze the expression of CD44-messenger RNA (mRNA) in colorectal cancer and colorectal adenoma to further elucidate the role of CD44 in colorectal tumorigenesis. METHODS: The expression of CD44-mRNA was examined in 90 specimens from 44 patients with colorectal cancer or colorectal adenomatous polyps and in the peripheral blood leukocytes from 7 healthy volunteers by reverse transcription-polymerase chain reaction and Southern blot hybridization. RESULTS: Strong expression of the epithelial form and variant forms containing exons 11 or 12 of the CD44 gene, which conferred metastatic behavior to rat cells, was detected in primary and metastatic tumor tissues, whereas it was very weak or not detectable in normal colonic mucosae, normal liver tissue, or peripheral blood leukocytes. However, adenomatous colorectal polyps also showed as strong an expression of epithelial and variant forms of CD44 as primary and metastatic tumor tissues. CONCLUSIONS: These results suggest that variant forms of CD44-mRNA might be expressed in an early stage of colorectal carcinogenesis.

Adenocarcinoma↗