Mark-release-recapture experiments to estimate the efficiency of the light trap in collecting Japanese encephalitis vector mosquitoes

Efficiency of the light trap in collecting females of Culex tritaeniorhynchus, the principal vector mosquito of Japanese encephalitis, was evaluated by mark-release-recapture experiments. Females collected with dry ice in the field were marked and released in a pigsty. The recapture rate of marked females by the light trap was so low as around 1% or lower. Owing to this low efficiency, it is not likely that the light trap can be a useful tool in the control of Japanese encephalitis.

Degeneration of intrahepatic bile duct with lymphocyte infiltration into biliary epithelial cells in biliary atresia

Degenerative changes of intrahepatic bile ducts with lymphocytic infiltration into portal areas have been recognized as the characteristic histopathologic features in the liver with biliary atresia (BA). Occasionally, lymphocytic infiltration into biliary ductal epithelium was noted and has been thought to be mostly the result of nonspecific chronic inflammation. However, this histological presentation looks quite similar to that of acute graft-versus-host disease (GVHD) after bone marrow transplantation (BMT) or acute cellular rejection (ACR) after orthotopic liver transplantation (OLTx). According to this histological similarity, we presumed that the degeneration of intrahepatic bile ducts (DIBD) might have developed with lymphocytic infiltration into biliary epithelial cells (LIBE) as some part of an immunologic reaction, and focused on the DIBD with LIBE in the patients with BA. Liver specimens obtained from 31 patients with BA at the time of primary Kasai operation and 3 patients at the time of reoperation were reviewed histologically, and investigated DIBD with LIBE. Nine patients with choledochal cyst (CBD) and 5 patients with neonatal hepatitis (NH) were added to this study as a control population. All patients with BA presented with DIBD with LIBE. On the other hand, only 2 patients with CBD presented with DIBD with LIBE, and no patients with NH presented with DIBD with LIBE. The DIBD with LIBE is not limited to patients with BA, but it seems to be much more serious in this group. These findings may suggest that some sort of immunologic factors contribute to the persistent DIBD in the patients with BA.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of cyclic AMP phosphodiesterase isozymes in rat parotid gland

Cyclic AMP phosphodiesterase (PDE) isozymes were isolated and characterized from the soluble fraction of rat parotid gland. Four main peaks containing PDE activity were obtained by Q-Sepharose Fast Flow column chromatography. The four peaks were identified as PDEs I-IV by kinetic properties, molecular-weight analysis and their responses to effectors and inhibitors.

Effect of PT-treatment on ANP-mediated inhibition of adenylate cyclase and amylase release in rat parotid gland

Effects of pertussis toxin (PT) treatment on atrial natriuretic peptide (ANP)-mediated inhibition of adenylate cyclase and amylase release were investigated in rat parotid gland. Adenylate cyclase activity stimulated by GTP gamma S in PT-treated membranes was much larger than that in normal membranes. ANP dose-dependently inhibited adenylate cyclase stimulated by GTP gamma S in control rat parotid membranes, however in membranes prepared from PT-injected (in vivo) rat parotid gland, ANP did not inhibit adenylate cyclase. ANP(10(-7)M) inhibited cAMP accumulation stimulated by forskolin (10(-6)M) in control rat parotid acinar cells by about 34%, however, in PT-treated cells, the inhibitory effect of ANP was attenuated completely. In control cells amylase release stimulated by isoproterenol (10(-6)M) and forskolin (10(-6)M) were also depressed by ANP (10(-7)M) by 27 and 30% respectively. The inhibitory response of ANP on amylase release was completely attenuated by PT-treatment. Gi was detected as a ADP-ribosylated 41-KDa protein by incubation of parotid membranes with PT and [alpha-32P]NAD. In rat parotid gland, these results suggested that ANP mediates adenylate cyclase/cAMP system and consequently reduces amylase release through ANP-C receptor coupled to Gi.

Influence of atrial natriuretic peptide on cyclic nucleotides and amylase release in rat parotid salivary gland in vitro

Atrial natriuretic peptide (ANP), sodium nitroprusside and hydroxylamine increased cGMP accumulation in rat parotid acinar cells both in the presence and absence of forskolin but in a different manner. On the other hand, ANP decreased forskolin-stimulated cAMP accumulation, although sodium nitroprusside and hydroxylamine had no effect on cAMP accumulation. Amylase release stimulated by forskolin, dibutyryl-cAMP or isoproterenol was depressed by ANP, whereas sodium nitroprusside and hydroxylamine did not evoke the inhibition of forskolin-stimulated amylase release. These results suggest that the inhibition of cAMP accumulation and of amylase release by ANP were not mediated via cGMP produced by guanylate cyclase-A.

[Long-term prognosis of the interferon-treated patients with chronic hepatitis C: compared with the natural course]

To evaluate the prognosis of the interferon (IFN)-treated patients with chronic hepatitis C (CH (C)), the clinical course and outcome of patients with CH (C) who were administered IFN more than 5 years before was compared with the natural course of untreated patients with CH (C) who were followed-up for 5 years. Good responders to IFN therapy showed normalized serum ALT level thereafter except one patient who were positive for serum HCV-RNA and had relapse of hepatitis. Histological improvements were observed in good responders. In groups of poor responders and non-responders, the fluctuation of serum ALT and histological changes after IFN therapy seemed to be similar to the natural course. Several problems on the prognosis are discussed.

Quantitation of hepatitis C virus RNA in liver tissue as a predictive marker of the response to interferon therapy in chronic hepatitis C

Recently, factors predicting the response to interferon (IFN) therapy against hepatitis C virus (HCV) have received much attention. To evaluate the usefulness of the quantitation of intrahepatic HCV RNA as a predictive marker of the response to IFN therapy, we compared the amount of intrahepatic HCV RNA with serum levels in 16 patients. Eleven patients who had 10(10) copies/g or more of intrahepatic HCV RNA had increased level of serum alanine aminotransferase (ALT) after IFN therapy, while 4 of 5 patients who had less than 10(10) copies/g of intrahepatic HCV RNA achieved sustained normalization of serum ALT level and were designated as complete responders. Four complete responders possessed significantly less HCV RNA in the liver parenchyma than partial and nonresponders (P = 0.010, Mann-Whitney U-test), but the amount of HCV RNA in the serum was not significantly different between those groups. In conclusion, the results suggest that the quantitation of intrahepatic HCV RNA is a better indicator of the response to IFN therapy than serum HCV RNA.

Quantitative detection of hepatitis C virus genome in liver tissue and circulation by competitive reverse transcription-polymerase chain reaction

We quantified hepatitis C virus RNA in 25 Japanese patients with chronic type C liver disease by competitive reverse transcription-polymerase chain reaction. The amount of the viral RNA in the serum (2 x 10(5)-2 x 10(8) copies/ml) correlated with that in the liver tissue (10(8)-10(11) copies/g) (N = 23, r = 0.727, P < 0.0001). One gram of the infected liver tissue contained 10(2)-10(4) (geometric mean, 10(3), N = 23) times as many copies of the viral RNA as did 1 ml of the serum. Liver tissues of chronic aggressive hepatitis contained significantly higher amounts of the viral RNA than those of chronic persistent hepatitis (P < 0.05). These observations suggested that this method is useful to evaluate viral amount, and the amount of the circulating hepatitis C virus RNA could be used as a marker of the intrahepatic viral amounts, which might contribute to disease activity.

[Clinical evaluation of choledochoduodenal fistula near the duodenal papilla: association with separate openings of the pancreatic and biliary ducts]

A total of 1293 patients who underwent ERCP between 1980 and 1990 were reviewed. A parapapillary choledochoduodenal fistula (PCDF) was noted in 42 patients (3.2%). In order to study the frequency of PCDF, the patients were divided into groups of age of ten years. As a result, PCDF was formed to increase with advance in age. Thus the dispose is regarded as a "later on" disease. Thirty-one of these patients were included in the definite PCDF group, in which the distance between the papillar and fistulous opening was confirmed by cannulation or choledochography, and 11 in the questionable PCDF group, in which the distance was not confirmed, and thus the opening might be the separate openings of the pancreatic and biliary ducts (Mehnen's type I). The frequency of pneumobilia, biliary stone, history of cholecystectomy, biliary inflammation and obstruction were similar in the two groups. Only one patient suspected of having separate openings of the pancreatic and biliary ducts except the questionable PCDF was seen over the same period. This suggests that majority of the cases of separate openings of the pancreatic and biliary ducts, whose prevalence is estimated to be 2-4% in Japan, may be PCDF.

Evaluation of antibody against AR142, a synthetic peptide derived from the core sequence of hepatitis C virus, in the diagnosis of non-A, non-B chronic liver disease

We evaluated serum anti-hepatitis C virus (HCV) using a synthetic peptide (AR142) which includes an epitope in the core region of HCV. The incidence of anti-AR142 in 98 patients with type non-A, non-B chronic liver diseases (NANB-CLD) was 89.8%, while all the 28 patients with non-type C chronic liver diseases were negative for anti-AR142. Among 98 NANB-CLD patients, 74 were positive for both anti-AR142 and anti-C100-3, 23 showed discordant results, and one was positive for neither. Eighty-one NANB-CLD patients underwent reverse transcription-polymerase chain reaction assay to detect viremia and 76 (93.8%) had a detectable level of HCV-RNA. Titers of anti-AR142 were not different among groups of different disease activities, genotypes of HCV, nor amount of serum HCV-RNA. These observations suggest that anti-AR142 could be a useful marker for chronic HCV infection.

Detection of negative strand RNA of hepatitis C virus in infected liver and serum

The negative strand RNA of hepatitis C virus, supposed to be a replicative intermediate of the virus appears to indicate viral replication. In this study, we detected the negative strand RNA by using reverse transcription-polymerase chain reaction with RNase A digestion to degrade the remaining positive strand genomic sequence of the virus after complementary DNA (cDNA) synthesis. In vitro transcribed positive-stranded mutant RNA was not detected by this method. Sample sera and liver tissues of 16 patients with chronic hepatitis C virus infection (liver fibrosis, 1; chronic hepatitis, 13; liver cirrhosis, 2) were analysed for negative strand RNA of hepatitis C virus. The negative strand RNA sequence was detected in 15 (93%) of 16 liver tissues and in 11 (78%) of 14 sera. The study demonstrated that negative strand RNA of hepatitis C virus in serum and liver tissue could be specifically detected.

[An epidemiological study on chronicity and incidence of hepatocellular carcinoma in the sequence of epidemic hepatitis]

From November 1951 to 1954, 416 patients in Kumayama Town, Okayama Prefecture, suffered from epidemic hepatitis, so-called "Kumayama Hepatitis". The mortality rate was 13.98% in the first one year, and the rate of progress to chronic hepatitis after 10 years was 24.6%. In the present study surveyed in 1991, 720 residents in this area had 13.6% positive anti-HCV (C100-3), significantly higher than in control areas. The rate of positive anti-HBs and abnormal liver functions in the subjects with positive anti-HCV was 42.9% and 40.8%, respectively. In 29 patients with clinically typical "Kumayama Hepatitis", the positivity rate of anti-HA IgG, anti-HBs, and anti-HCV, and the prevalence of abnormal liver function was 82.8%, 41.4%, 34.5%, and 10.3%, respectively. In conclusion, it is suggested that the hepatitis epidemic in Kumayama Town was caused by HAV and superinfected by HCV and/or HBV, then its clinical manifestations became complicated.

[Antimicrobial activity of clarithromycin and its effect on bacterial adherence to medical material]

Antimicrobial activity of clarithromycin (CAM) in comparison with other 6 macrolides was determined against 419 recent clinical isolates including Streptococci, Enterococci, Staphylococci, Moraxella, Haemophilus and Bacteroides strains. MICs80's of CAM against Streptococcus pneumoniae, Streptococcus pyogenes and Streptococcus agalactiae were 0.78, 0.10 and 0.10 microgram/ml, respectively. MICs80's against Moraxella catarrhalis and Haemophilus influenzae were 0.05 and 1.56 micrograms/ml, respectively. Laboratory-induced resistance to CAM in strains of S. pneumoniae, Enterococcus faecalis or methicillin-sensitive Staphylococcus epidermidis occurred in stepwise fashion and at a very low rate. Adherence to silicon filter of strains of Pseudomonas aeruginosa or S. epidermidis was strongly repressed by the addition of sub-MIC of CAM or other macrolides. Although tosufloxacin (TFLX) alone had no bactericidal activity against the sessile cells of P. aeruginosa strains tested, TFLX showed synergistic bactericidal activity when combined with sub-MICs of CAM or erythromycin.

Current concept of the treatment of biliary atresia

Hepatic portoenterostomy (Kasai operation) for the patient with biliary atresia (BA) can restore the bile flow in approximately 80% of children operated on before 60 days of life [1]. However, in terms of long-term survival, according to a recent nationwide survey among the major pediatric centers in Japan, only 325 of 2013 patients had more than 10 years' survival, and only 157 patients (7.8%) remained jaundice-free with normal liver function [2]. About 20% of BA cases without jaundice are generally able to survive for long periods; and most of those patients have portal hypertension or abnormal liver function [3-5]. As the results of liver transplantation have improved, controversy has arisen over the optimal care of these children [4, 6, 7]. Some investigators have claimed that transplantation is the favored primary therapy for most patients with BA [8]. We are thus at a turning point concerning the primary therapy of BA, which makes it necessary to determine the exact indications for the Kasai portoenterostomy and the timing of liver transplantation. This paper describes our strategy for the optimal treatment of BA patients based on our 117 patients who have had various form of portoenterostomy.

Quantitative hepatitis C virus RNA and liver histology in chronic hepatitis C patients treated with interferon alfa

Seventy patients with hepatitis C virus (HCV) infection received alpha interferon at doses ranging from 3 to 10 million units (MU) daily for eight weeks, three times weekly for 12-24 weeks, or daily and three times weekly for 12-24 weeks. The efficacy of interferon was closely related to the initial blood HCV-RNA values in that these were lower in those who responded completely and partially compared with non-responders. Continuous reductions in HCV-RNA and improvements in the histology activity index score were seen in those who responded completely. In contrast, most of the partial and non-responders remained HCV-RNA positive.

Hepatitis type C virus infection in patients with type B chronic liver disease

Anti-c100-3 (Ortho) was determined in the sera of 152 patients with HBs antigen-positive chronic liver diseases to assess coinfection of hepatitis B virus (HBV) and hepatitis C virus (HCV). Eleven patients (7.2%) were positive for anti-c100-3. Anti-CP-9 (Okamoto) and HCV-RNA (RT-PCR) were also examined in these 11 patients. Anti-CP-9 was detected in 7 patients and HCV-RNA was detected in all 11 patients. Four of the 11 anti-c100-3-positive patients were positive for HBe antigen (HBeAg) and others were negative. In 8 of the 11 patients, HCV was suspected to be superinfected by blood transfusion. In HBeAg-positive patients, serum glutamic pyruvic transaminase (SGPT) was elevated in relation to active replication of HBV shown by DNA-polymerase activity. The histological findings showed chronic active hepatitis, with or without cirrhosis. On the other hand, in HBeAg-negative patients, SGPT fluctuated without evidence of active replication of HBV. Active inflammation in the liver was observed in 3 of 5 HBeAg-negative patients by liver biopsy. These findings suggest that HBV might play an important role in chronic active inflammation in HBeAg-positive patients coinfected with HCV, and that HCV might be responsible for continuous inflammation in HBeAg-negative patients coinfected with HCV.

Hepatitis C virus antibody titration in patients with chronic hepatitis C, before and after interferon treatment

We measured hepatitis C virus antibody titers in 13 patients with chronic hepatitis C to determine whether titration of hepatitis C virus antibody was useful or not, to predict and evaluate the efficacy of interferon (IFN) treatment. During administration of IFN, hepatitis C virus titers declined in all patients. Antibody titers performed before treatment as well as just at the end of treatment did not correlate with change of the alanine aminotransferase levels during administration of IFN. Antibody titers declined continuously after treatment in 5 patients with normal alanine amino-transferase levels for over 6 months after discontinuation of IFN. Antibody titers rose again in 6 patients whose alanine aminotransferase levels fluctuated after treatment. An exceptional pattern of change occurred in 2 patients whose antibody titers declined continuously although their alanine aminotransferase levels fluctuated after treatment. Repeated titration of hepatitis C virus antibody appears to be useful for evaluating the long-term efficacy of IFN treatment.

Anti-C100-3 antibody status, viral genomic sequences, and clinical features in chronic hepatitic patients with hepatitis C virus RNA in sera

Since detection of hepatitis C virus RNA by the polymerase chain reaction (PCR) showed that there existed anti-C100-3 (anti-HCV) antibody negative patients infected with HCV, we attempted to find out whether there were any clinical or viral genomic differences between the anti-HCV antibody positive and negative groups. One hundred and fifty-nine patients with chronic liver diseases with hepatitis C virus RNA in their sera were selected. Anti-HCV antibody was tested for anti-C100-3 antibody by an enzyme linked immunosorbent assay. The incidence of anti-HCV antibody was 129/159. The concentration of serum gamma-globulin, the titier of ZTT, and the positive rate of the PCR with the primers of the NS3/4 region (NS3/4PCR) were significantly higher in the anti-HCV antibody positive group than in the negative group. However, the other data such as alanine aminotransferase activity or past history were not significantly different. Nucleotide sequence of the cDNA fragments of NS3/4 region amplified by the PCR did not differ significantly between isolates from anti-HCV antibody positive and negative sera. The sequences observed in the present study did not differ significantly from those reported previously. Although there remains the possibility that the variation of viral genomic sequences may cause the absence of anti-HCV antibody, these results suggested that the individual clinical backgrounds or immunoreactivity of the patients might influence the antibody development.

Congenital biliary atresia and congenital biliary dilatation in siblings

Congenital biliary atresia or congenital biliary dilatation in siblings have been reported, although the genetic influences in these diseases are considered to be obscure. We report a case of congenital biliary atresia and congenital biliary dilatation in sisters.