Peginterferon add-on results in more HBsAg decline compared to monotherapy in HBeAg-positive chronic hepatitis B patients

It is unknown whether peginterferon (PEG-IFN) add-on to entecavir (ETV) leads to more HBsAg decline compared to PEG-IFN monotherapy or combination therapy, and whether ETV therapy may prevent HBsAg increase after PEG-IFN cessation. We performed a post hoc analysis of 396 HBeAg-positive patients treated for 72 weeks with ETV + 24 weeks PEG-IFN add-on from week 24 to 48 (add-on, n = 85), 72 weeks with ETV monotherapy (n = 90), 52 weeks with PEG-IFN monotherapy (n = 111) and 52 weeks PEG-IFN + lamivudine (combination, n = 110) within 2 randomized trials. HBsAg decline was assessed at the end of PEG-IFN (EOP) and 6 months after PEG-IFN (EOF) discontinuation. Differences in baseline characteristics were accounted for using inversed probability of treatment weights. At EOP, a HBsAg reduction of ≥1log10 IU/mL was more frequently achieved for patients in the add-on or combination therapy arms (both 36%), compared to PEG-IFN mono (20%) or ETV (8%) (add-on vs PEG-IFN mono P = 0.050). At EOF, the HBsAg reduction ≥1log10 IU/mL was only sustained in patients treated with ETV consolidation (add-on vs combination and PEG-IFN mono: 40% vs 23% and 18%, P = 0.029 and P = 0.003, respectively). For add-on, combination, PEG-IFN mono and ETV, the mean HBsAg-level change at EOF was -0.84, -0.81, -0.68 and -0.33 log10 IU/mL, respectively (P > 0.05 for PEG-IFN arms). HBeAg loss at EOF was 36%, 31%, 33% and 20%, respectively (P > 0.05). PEG-IFN add-on for 24 weeks results in more on-treatment HBsAg decline than does 52 weeks of PEG-IFN monotherapy. ETV therapy may maintain the HBsAg reduction achieved with PEG-IFN.

Long-term entecavir or tenofovir disoproxil fumarate therapy in treatment-naïve chronic hepatitis B patients in the real-world setting

The aim of this study was to determine the long-term efficacy of entecavir (ETV) and tenofovir disoproxil fumarate (TDF) on the natural course of disease in chronic hepatitis B patients (CHB) with/without cirrhosis in clinical practice. A total of 355 treatment-naïve CHB patients were enrolled into the study. The primary outcome measure was viral suppression as defined by serum HBV DNA level <20 IU/mL. A secondary outcome measure was to determine the development of Hepatocellular carcinoma (HCC). Virological and biochemical responses were similar between the two treatment groups over time. The presence of cirrhosis and hepatitis B e antigen (HBeAg) positivity did not appear to impact viral suppression. The cumulative probability of HBeAg loss was 41% at 4 years of therapy. Hepatitis B surface antigen (HBsAg) loss occurred in four patients. Model for End-Stage Liver Disease score was significantly improved from baseline to week 48 and 96 under antiviral therapy (P = 0.013, P = 0.01). HCC was diagnosed in 17 patients (4.8%). The cumulative probability of the development of HCC was 3.3% at 1 year and 7.3% at 4 years of therapy. The development of HCC was independently associated with older age (P = 0.031) and the presence of cirrhosis (P = 0.004). Serum creatinine levels and creatinine clearance remained stable over time. ETV and TDF effectively maintained virological and biochemical responses in long-term follow-up of CHB patients with/without cirrhosis. HCC may still develop, although at a lower rate, and is more likely to develop in patients with cirrhosis, especially in older patients.

Loss of intrahepatic HBsAg expression predicts sustained response to peginterferon and is reflected by pronounced serum HBsAg decline

There is a lack of knowledge regarding the effect of peginterferon (PEG-IFN) on the expression of intrahepatic hepatitis B core and surface antigen (HBcAg and HBsAg) in chronic hepatitis B (CHB) and its relation with response to therapy. Fifty-two HBeAg-positive and 67 HBeAg-negative CHB patients with paired liver biopsies taken at baseline and after 1 year of PEG-IFN therapy were studied. After PEG-IFN therapy, HBeAg-negative patients showed a significant reduction in both intrahepatic HBcAg (P = 0.04) and HBsAg expression (P < 0.001). In contrast, a reduction in intrahepatic HBcAg expression was not observed in HBeAg-positive patients, while a trend in reduction of intrahepatic HBsAg staining was found (P = 0.09). Post-treatment, 7 (13%) HBeAg-positive and 9 (14%) HBeAg-negative patients had no expression of intrahepatic HBsAg. Patients without any intrahepatic HBsAg expression post-treatment were more likely to achieve a combined response (HBeAg loss with hepatitis B virus (HBV) DNA <2000 IU/mL for HBeAg -positive and HBV DNA <2000 IU/mL and normal alanine aminotransferase for HBeAg-negative CHB): 71% vs 5% for HBeAg-positive (P < 0.001) and 60% vs 16% for HBeAg-negative patients (P = 0.004), respectively. Moreover, a more profound decline of serum HBsAg was observed in patients with absence of intrahepatic HBsAg staining (3.1 vs 0.4 log IU/mL, P < 0.001 and 1.7 vs 0.4 log IU/mL, P = 0.005 for HBeAg-positive and HBeAg-negative CHB, respectively). In conclusion, PEG-IFN reduces expression of intrahepatic HBsAg. Loss of HBsAg as assessed by immunohistochemistry from the liver predicts a sustained response and is reflected in a pronounced serum HBsAg decline.

Polymorphisms of HLA-DP are associated with response to peginterferon in Caucasian patients with chronic hepatitis B

BACKGROUND

Polymorphisms of the HLA-DP gene are associated with the natural clearance of the hepatitis B virus in Asian patients.

AIM

To investigate the association of HLA-DP polymorphisms with response to peginterferon (PEG-IFN) in Caucasian chronic hepatitis B (CHB) patients.

METHODS

We studied 262 Caucasian chronic hepatitis B patients infected with HBV genotype A or D, treated with PEG-IFN for 1 year in two randomised controlled trials (HBV 99-01 and PARC study). Response was defined as an HBV DNA <2000 IU/mL at 6 months post-treatment. Variations at HLA-DPA1 and HLA-DPB1 were genotyped.

RESULTS

Of the 262 patients, 58% was HBeAg-positive and HBV genotype A and D was observed in 32% and 68%, respectively. At 6 months post-treatment, 57 (22%) patients had achieved an HBV DNA <2000 IU/mL. HLA-DPB1 was independently associated with virological response [adjusted odds ratio (OR) 1.8, 95% confidence interval (CI):1.1-3.0, P = 0.025], and with an undetectable HBV DNA (adjusted OR 2.4 95% CI: 1.2-4.7, P = 0.015) when adjusted for HBeAg status and other known response modifiers. In HBeAg-positive patients, combined HBeAg seroconversion with HBV DNA <2000 IU/mL was increasingly observed with each addition of an HLA-DPB1 G-allele (adjusted OR 2.7, 95% CI: 1.2-5.9, P = 0.012). Furthermore, HLA-DPA1 and HLA-DPB1 haplotype block GG showed comparable results for virological and combined response.

CONCLUSION

In this large cohort of Caucasian chronic hepatitis B patients infected with HBV genotypes A or D, polymorphisms of HLA-DP are independently associated with both virological and serological response to PEG-IFN therapy at 6 months post-treatment.

Comparison of sequence analysis and INNO-LiPA HBV DR line probe assay in patients with chronic hepatitis B

The aim of this study was to compare direct sequence analysis of partial HBV pol gene and Inno-LiPA HBV DR in serum samples of 120 chronic hepatitis B patients sent to the Clinical Microbiology Laboratory of Ege University Hospital because of lamivudine resistance. Sequence analysis was performed on ABI Prism 310 Genetic Analyzer. Comparison of Inno-LiPA and sequence results obtained by double-blind evaluation showed full agreement (both at rt180 and rt204) in 58.8% of samples. Visually rechecking of the electropherograms increased this rate to 68.3% Codon based rates are 81.7% and 75.8% at rt180 and rt204 respectively. LiPA detected variants in additional 12 (10%) samples, but missed one variant sample (both rt180 and rt204) and one sample was indeterminate due to poor probe binding. LiPA allows determination of mixed variants and seems to be more sensitive and simple for routine testing even though sequence analysis is still the gold standard for detecting new variants.

Gastrointestinal effects of selective and non-selective non-steroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed group of drugs. Patients receiving NSAIDs often experience abdominal discomfort, and some of them develop serious gastrointestinal complications, such as ulceration, bleeding, perforation, or obstruction. Gastrointestinal side effects of NSAIDs are mostly attributed to cyclooxygenase (COX) inhibition resulting in reduction of prostaglandin in gastric mucosa. Topical irritant effects are also contributed to their systemic effect of prostaglandin inhibition. Anti-inflammatory effects of NSAIDs are mediated by COX-2 inhibition, while COX-1 inhibition is responsible for gastric prostaglandin inhibition. Management of gastrointestinal complications of NSAIDs is costly. In order to prevent or treat the gastrointestinal complications of NSAIDs, anti-ulcer drugs can be used concomitantly. Other alternative is the application or substitution of COX-2 selective inhibitors, which spare gastric mucosal prostaglandin synthesis and do not damage the gastric mucosa. Application of COX-2 selective inhibitors as a first line treatment for arthritic disorders may not be cost-effective, if patients do not have any risk factors including advanced age, history of complicating peptic ulcer, concomitant anticoagulant and corticosteroid medication. Patients with risk factors or those developing gastrointestinal complications during the course of NSAID treatment can be treated with COX-2 selective inhibitors if necessary.

The safety of pegylated interferon alpha-2b in the treatment of chronic hepatitis B: predictive factors for dose reduction and treatment discontinuation

BACKGROUND

Treatment with interferon-alpha has been shown to be effective in one-third of hepatitis B e antigen-positive chronic hepatitis B patients, but is clinically associated with relevant adverse events.

AIM

To investigate the safety of pegylated interferon alpha-2b in 300 hepatitis B e antigen-positive patients with compensated liver disease.

METHODS

Patients were treated with pegylated interferon alpha-2b for 52 weeks combined with either lamivudine 100 mg/day or placebo. Pegylated interferon alpha-2b was administered for 100 microg once a week for 32 weeks; thereafter, the dose was reduced to 50 microg once a week. Adverse events and their effect on study medication were reported at monthly visits in a standardized way.

RESULTS

The most frequently reported side-effects were flu-like syndrome (68%), headache (40%), fatigue (39%), myalgia (29%) and local reaction at the injection site (29%). These symptoms typically occurred within the first month of therapy and subsided during the course of therapy. Neutropenia and thrombocytopenia induced by pegylated interferon alpha-2b increased the risk of infections and bleeding complications, but these complications were rare and mild. The frequency of all side-effects was not different between patients treated with pegylated interferon alpha-2b combined with lamivudine or placebo. In 69 (22%) patients the dose of pegylated interferon alpha-2b was reduced prematurely. Of these dose reductions, 36 (52%) were because of neutropenia. Therapy was discontinued in 28 (8%) patients. The most frequent reasons for early discontinuation were psychiatric side-effects (depression, psychosis) and flu-like symptoms. Multivariate Cox regression analysis showed that low neutrophil count at baseline and cirrhosis were independent predictors of dose reduction or therapy discontinuation.

CONCLUSION

We conclude that in patients with chronic hepatitis B and compensated liver disease prolonged pegylated interferon alpha-2b therapy is safe, and that pre-existent cirrhosis and neutropenia are the most important predictors of dose reduction or early treatment discontinuation.

Functional dyspepsia: relationship between clinical subgroups and Helicobacter pylori status in Western Turkey

The etiology of functional dyspepsia is not known. The objective of the present study was to determine the characteristics of functional dyspepsia in Western Turkey. We divided 900 patients with functional dyspepsia into three subgroups according to symptoms: ulcer-like (UL), 321 (35.6%), motility disorder-like (ML), 281 (31.2%), and the combination (C) of these symptoms, 298 (33.1%). All patients were submitted to endoscopic evaluation, with two biopsies taken from the cardia and corpus, and four from the antrum of the stomach. All biopsy samples were studied for Helicobacter pylori (Hp) density, chronic inflammation, activity, intestinal metaplasia, atrophy, and the presence of lymphoid aggregates by histological examination. One antral biopsy was used for the rapid urease test. Tissue cagA status was determined by PCR from an antral biopsy specimen by a random sampling method. We also determined the serum levels of tumor necrosis factor-alpha (TNF-alpha) and gastrin by the same method. Data were analyzed statistically by the Kolmogorov-Smirnov test and by analysis of variance. Hp and cagA positivity was significantly higher in the UL subgroup than in the others. The patients in the ML subgroup had the lowest Hp and cagA positivity and Hp density. The ML subgroup also showed the lowest level of Hp-induced inflammation among all subgroups. The serum levels of TNF-alpha and gastrin did not reveal any difference between groups. Our findings show a poor association of Hp with the ML subgroup of functional dyspepsia, but a stronger association with the UL and C subgroups.

TT virus infection and genotype distribution in blood donors and a group of patients from Turkey

BACKGROUND

TT virus (TTV) DNA has been found in a large proportion of patients with different forms of non-A-G hepatitis, however the clinical importance is unclear. We aimed to determine the genotypes of TTV isolates found in blood donors and different patient groups from the western part of Turkey.

MATERIALS AND METHODS

TT DNA was investigated in serum samples of 91 volunteer blood donors (BD), 105 thalassemia (TH) patients, ten patients with fulminant hepatitis (FH) and 16 hemodialysis (HD) patients by heminested PCR using primers NG059, NG061 and NG063 from the ORF1 region. 39 isolates were genotyped by analyzing the partial sequence of ORF1.

RESULTS

TTV DNA was found in 75% of HD, 80% of FH, 61% of TH patients and in 51.6% of BD. Among the sequenced isolates, 14 (35.9%) belonged to genotype 1 (G1) and 25 (64.1%) belonged to genotype 2 (G2). Among the G2 sequences, 22 were grouped as G2c.

CONCLUSION

TTV infection was common in the population studied, even with moderately sensitive primers. G2 was the major genotype of the studied population without any significant differences in distribution between various patient groups and BD.

Nitroimidazole-induced chronic hepatitis

Drug-induced chronic hepatitis is a rare pathological condition. There is no reported case with chronic hepatitis secondary to nitroimidazole use. We report a patient who developed nitroimidazole-induced chronic hepatitis following acute exacerbation of hepatitis three times after nitroimidazole use.

Severe toxic hepatitis associated with amoxycillin and clavulanic acid

Toxic hepatitis secondary to amoxycillin-clavulanic acid is an infrequent clinical picture. Most of the cases are reported to have a benign course. We report two cases of severe hepatic failure following amoxycillin-clavulanic acid use. One of the cases had cholestatic features primarily, and the other had hepatocellular injury prominently. The first case had also findings of trombotic trombositic purpura and had a fatal course.

Clinicopathological features of rapidly progressive hepatitis C virus infection in HCV antibody negative renal transplant recipients

BACKGROUND

Hepatitis C virus (HCV) infection acquired during dialysis treatment generally shows a relatively benign course after renal transplantation (RTx). However, less is known about the course of HCV infection acquired during or after RTx.

METHODS

Clinical and histopathological assessment of 15 renal transplant recipients who acquired HCV infection during or after RTx.

RESULTS

Alanine aminotransferase levels rose for the first time 1-19 weeks after RTx. HCV RNA was found positive in all patients, but anti-HCV became positive in only nine of them. During a mean follow-up of 21 +/- 12 months, jaundice appeared in 12 patients while ascites and/or hepatic encephalopathy occurred in six. Azathioprine was stopped in all patients. Cyclosporin was also stopped in four patients and in two of them prednisolone was also interrupted for a period of 3-7 weeks. Following this, ascites, hepatic encephalopathy and biochemical disturbances improved, while no deterioration was seen in graft function. Nine of the 15 patients had undergone two consecutive liver biopsies (LB). The first LB revealed cirrhosis in three and chronic hepatitis in six patients; the second LB showed cirrhosis in seven patients. The histological activity index (Knodell's score) progressed from 11.8 +/- 3.5 to 13.8 +/- 3.8.

CONCLUSIONS

The results suggest that HCV infection acquired during or after RTx may run an unusual and rapidly progressive clinical and histopathological course at least in some of these patients. Decrease or withdrawal of immunosuppressive drugs may improve early hepatic failure without detrimental effect on graft function during that period.

Possible role of glutathione in prevention of acetaminophen-induced hepatotoxicity enhanced by fish oil in male Wistar rats

It has been reported that fish oil protects the rat liver against acetaminophen (APAP) induced toxicity; however, this finding is controversial. The present study was undertaken to investigate the effects of fish oil-enriched diet on APAP-induced liver injury in Wistar rats. Rats were fed a diet supplemented with either 8% fish oil or 8% corn oil, or standard rat feed for 6 wk. After an overnight fast, rats in each group were given either 2 g/kg APAP or saline orally. Our findings showed that APAP increased serum alanine aminotransferase (ALT) and that this rise was potentiated in the presence of dietary fat. Further fish oil ingestion increased the glutathione (GSH) content in rat liver; however, this was not effective in protecting liver from APAP-induced toxicity. Data suggest that GSH may be necessary to detoxify APAP metabolites, which are known to induce hepatotoxicity but are increased by dietary fat.

High degree of conservation in the hepatitis B virus core gene during the immune tolerant phase in perinatally acquired chronic hepatitis B virus infection

BACKGROUND

Mutations in the hepatitis B virus genome have been implicated in the persistence of hepatitis B virus infection and the pathogenesis of hepatitis B virus related liver disease. In view of the heterogeneity in published sequences, data from cross-sectional studies of unrelated subjects cannot differentiate true mutations from infections with variant sequences.

AIMS/METHODS

We compared the hepatitis B virus core gene sequences of 42 HBsAg positive subjects from 11 Chinese families with those of the index patients (maternal carriers) to determine the frequency and rate of true hepatitis B virus core gene mutations in patients with chronic hepatitis B virus infection.

RESULTS

Completely identical nucleotide sequences were present in all the family members and index patients in two families, suggesting that the hepatitis B virus core gene can be conserved for more than 20 years. The high degree of sequence conservation in these families is related to the young age of the subjects (mean 19.2+/-8.9 years), the fact that they were all HBeAg positive and that 75% of them had persistently normal aminotransferase levels. Longitudinal studies confirmed that mutations were rare in those who remained HBeAg positive with normal aminotransferase levels (immune tolerant phase), but significantly more common in HBeAg positive subjects who had elevated aminotransferase levels and in those who cleared HBeAg (immune clearance phase), the rates of nucleotide and amino acid changes were respectively: 0.28+/-0.12 vs 1.30+/-0.26/10(3) nt position/yr and 0.04+/-0.01 vs 0.18+/-0.5/10(2) codon/yr.

CONCLUSIONS

Identical nucleotide differences could be found in the sequences of all the subjects in some families. These differences were more likely to be due to intra-familial transmission of stable variants. Sequence analysis based on comparisons with published sequences would have led to over-reporting of mutations. The hepatitis B virus core gene can remain highly conserved for more than two decades during the immune tolerant phase of perinatally acquired chronic hepatitis B virus infection. However, significant changes can occur within 2-3 years during the immune clearance phase.

Naturally occurring hepatitis B virus core gene mutations

Mutations in the hepatitis B virus (HBV) core gene may influence disease activity by altering immune recognition sites or level of virus replication. Sera from 69 Chinese patients with chronic HBV infection were analyzed by direct sequencing of polymerase chain reaction amplification of HBV DNA to determine the frequency and location of naturally occurring HBV core gene mutations. All but one patient had nucleotide changes, and 44 (64%) patients had at least one amino acid change (mean, 3.7; range, 1-13) when compared with published sequences. Multiple regression analysis showed that the frequency of core gene mutations was significantly associated with precore stop-codon mutation, hepatitis B e antigen negativity, and active liver disease, but not patients' age. The mean number of amino acid changes/patient for hepatitis B e antigen (HBeAg)-positive patients with elevated versus normal aminotransferase levels were, respectively, 2.8 +/- 0.4 and 0.6 +/- 0.2. The corresponding values for HBeAg-negative patients were, respectively, 5.0 +/- 1.2 and 6.0 +/- 1.5. Thirteen patients were serially studied, the mean rates of amino acid substitution in HBeAg-positive patients who did or did not clear HBeAg during follow-up were 5.7 +/- 0.8 and 0 per codon/yr. Most of the mutations were clustered in the codon/yr. Most of the mutations were clustered in the middle of the core gene that harbor several major B- and helper T-cell epitopes. Very few mutations were found in the C-terminal part of the core gene. In summary, mutations in the core gene can be frequently detected in patients with chronic HBV infection. These mutations occur predominantly around the time of HBeAg clearance when liver disease is most active.

Naturally occurring core-gene-defective hepatitis B viruses

This study was undertaken to determine the prevalence of core-gene-defective hepatitis B virus (HBV) in patients with chronic HBV infection, and the nature and significance of the deletions. PCR was performed on sera from 263 patients with chronic HBV infection. Seventeen (6.5%) patients had smaller band(s) in addition to a band of the expected size. Additional bands were also detected in the follow-up samples from 80% and 3% patients who had respectively, multiple and single bands initially. Six patients were further studied by direct sequencing. Four patients had in-frame deletions leading to loss of codons 79-122 of the core gene. Two patients had identical frameshift deletions of nucleotides 2204-2333 resulting in the loss of the first nine codons of the overlapping P gene. Follow-up samples from three of four patients studied showed deletions identical to those in the initial samples. The persistence of these deletions suggests that they were stable and that they may contribute to the chronicity of infection.

Effect of PACAP on gastric acid secretion in rats

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a new VIP-like brain-gut peptide. Its effects on the motility and secretory functions of the gastrointestinal system have been shown in previous studies. In this study we investigated the effect of intravenous PACAP on gastric acid secretion in conscious pylorus-ligated rats and in gastric fistula rats. PACAP showed significant inhibitory effects on pentagastrin- and histamine-stimulated gastric acid secretion, but no effect on basal or carbachol-stimulated secretion in pylorus-ligated rats. It did show dose-related inhibitory effects both on basal gastric acid secretion and on secretion stimulated by pentagastrin, histamine, or carbachol in gastric fistula rats. PACAP did not alter serum gastrin levels. Inhibition of prostaglandin synthesis with indomethacin and immunoneutralization of somatostatin with anti-somatostatin serum did not prevent the inhibitory effect of PACAP on gastric acid secretion in pylorus-ligated rats. We conclude that PACAP most likely has a direct effect on parietal cells and that this effect may be mediated, at least partially, by inhibition of the action of histamine on parietal cells.

Predictive value of precore hepatitis B virus mutations in spontaneous and interferon-induced hepatitis B e antigen clearance

We previously reported two mutually exclusive mutations in the precore region of hepatitis B virus: M1 (T-1856, proline-serine substitution at codon 15) and M2 (A-1896, stop codon at codon 28). This study was conducted to determine if the presence of precore mutants affect spontaneous or interferon (IFN)-induced hepatitis B e antigen (HBeAg) clearance. Sera from 201 hepatitis B e antigen positive Chinese patients (including 106 who participated in a controlled trial of IFN therapy) with chronic hepatitis B virus (HBV) infection were analyzed by direct sequencing of HBV DNA after amplification by polymerase chain reaction (PCR) assay. Forty-three (21%) patients had M1 (T-1856), and 20 patients (10%) had M2 (A-1896). During a follow-up period of 1 to 7 years, 75%, 28%, and 26% of those with M2 (A-1896), M1 (T-1856), and wild type sequence respectively, cleared HBeAg (P < .0001). Eighteen (67%) of 27 patients with wild-type sequence but none of 10 patients who had M1 (T-1856) in their initial samples developed M2 (A-1896) after loss of HBeAg (P < .0001). Sustained antiviral response was achieved in 55%, 0%, and 17% of interferon-treated patients who had M2 (A-1896), M1 (T-1856), and wild-type sequence, respectively, initially (P = .04). However, patients with M2 (A-1896) were also more likely to have elevated pretreatment aminotransferase levels (P = .02). In summary, HBeAg-positive Chinese patients with M2 (A-1896) were mor likely to clear HBeAg, and to do so earlier.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of precore hepatitis B virus mutants in asymptomatic HBsAg-positive family members

Precore hepatitis B virus mutants have been detected mainly in HBeAg-negative patients with active liver disease. We previously reported two novel mutations: M1 (C-to-T change at nucleotide 1856 [proser at codon 15]) and M3 (G-to-A change at nucleotide 1898 [gly-ser at codon 29]) in addition to two well-described mutations: M2 (G-to-A change at nucleotide 1896 [trp-stop at codon 28]); and M4 (G-to-A change at nucleotide 1899 [gly-asp at codon 29]) in Chinese patients. The aims of this study were to determine (a) the prevalence of precore HBV mutations in asymptomatic carriers and (b) whether family members share the same mutated sequence as the index patients. Fifty-three index patients and 89 HBsAg-positive family members were studied by means of direct sequencing of polymerase chain reaction-amplified hepatitis B virus DNA. M0, a conserved mutation (T-to-C at nucleotide 1858, codon 15), was detected in 81% and 12% family members of index patients with and without M0, respectively (p < 0.0001). The clustering of M0 indicates that most subjects were infected through intrafamilial transmission. M1 was detected in all the family members of patients with M1 but in none of the family members of patients with wild-type or M2 sequences (p < 0.0001). M2 was detected in 25%, 0% and 15% of family members of patients with M2, M1 and WT sequences, respectively (p = 0.19). M3 was detected in five and M4 in four family members.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of somatostatin receptor subtypes controlling rat gastric acid and pancreatic amylase release

An examination of the binding characteristics of a large number of somatostatin analogues with respect to the five known somatostatin receptor subtypes has recently resulted in the discovery of several peptides with some selectivity for types 2, 3, and 4 and little affinity for type 1 or 5 receptor. A panel of these peptides has thus far implicated type 2 receptors in the inhibition of release of pituitary growth hormone and type 4 receptors in inhibiting pancreatic insulin release. In the present article, we have examined the inhibitory effects of the same group of peptides on in vivo rat gastric acid and pancreatic amylase release and binding to rat pancreatic acinar cells. The type 2-selective ligand NC-8-12 was a potent inhibitor of gastric acid release (EC50s in the 1.5 nM region) whereas the type 4-selective ligand, DC-23-99, elicited little response. However, some involvement of type 3 receptors could not be ruled out because the type 3-selective analogue, DC-25-20, exhibited inhibitory effects at higher dose levels (EC50 > 10 nM). Conversely, the type 4 analogue was a potent inhibitor of amylase release (EC50 1.1 nM) whereas the type 3 analogue had no significant effects at doses tested. DC-23-99 also bound with high affinity to rat acinar cells (EC50 3.8 nM), whereas DC-25-20 exhibited more than 10-fold less affinity. Thus, these two major biological functions of somatostatin appear to be controlled by different receptors and, furthermore, effects on both endocrine and exocrine pancreas appear to be type 4 receptor mediated.