Persistent Negative Anti-Bc in Chronic Hepatitis B Virus Carrier: linical Review, HBcAg and Nucleotide Sequence of It's Epitope in HLA A2 Heterozygotes / 대한간학회지

BACKGROUND/AIMS: HBcAg is the most immunogenic HBV component and anti-Bc usually persists irrespective of ongoing liver disease or clearance of the virus in human. Therefore anti-Bc is considered as the most sensitive and occasionally the only marker of the HBV infection. Nevertheless, there are a few HBsAg carrier with persistent negative anti-Bc. The epitope which responds to HBcAg is recently defined in HLA A2 from acute viral hepatitis patient due to HBV. So we studied the clinical and laboratory features and nucleotide sequence of HBcAg corresponding to HLA A2 in the HBsAg carrier with persistent negative anti-Bc. METHODS: The subject of these study consists of eight HBsAg chronic carriers with persistent negative anti-Bc. We followed up the clinical features and serological markers of HBV infection and determined the amount of humoral immunoglobulin, HBV DNA and HBcAg when we performed the HLA class I typing and sequencing analysis of core of HBV. Control cases were selected from 3 HLA A2 heterozygote cases with chronic HBsAg carriers with anti-Bc. RESULTS: All subjects had the HBsAg persistently and good health conditions with normal ranges of aminotransferase and humoral immunoglobulin. One of them was converted to anti-Bc-ositive during follow-p period. The level of HBV DNA in serum was higher than 1.2 pg/mL in 7 of 8 chronic HBV carriers. There was a trend of differences between chronic anti-Bc negative carriers and converted one case to anti-Bc positive in the serum of HBcAg and HBV DNA(p=0.06). But strong positive correlation was observed between the amount of HBcAg and HBV DNA in sera. The core portion of HBV was amplified in 4 of 6 HLA A2 heterozygotes by single PCR. When sequenced the PCR products of the above 4 chronic anti-Bc negative HBV carriers and 3 control cases directly, there were no significant difference in the nucleotide and amino acid sequence at the HBcAg epitope which corresopond to class 1 HLA A2. CONCLUSIONS: Our results show that persistent anti-Bc negative chronic HBV carriers may be caused by large amounts of HBV DNA and HBcAg in their sera and not by variants of HBV. These suggested that active viral replication was going on, but are undetectable by the available commercial tests due to binding with excessive amount of HBcAg in the HBV carriers with persistent negative anti-Bc.

Cardiovascular change to endotracheal intubation during anesthetic induction with midazolam-fentanyl / 대한마취과학회지

Thiopental sodium, a water-soluble barbiturate derivative with pH 10.0, reaches brain tissue in its highest concentration in about 50 seconds after intravenous injection. Blood concentration then decreases according to redistribution. Patients who are given midazolam as an induction agent are known to awake from general anesthesia relatively more slowly than those given pentothal sodium. Fentanyl, a potent analgesic, has been used in balanced anesthesia because of its minimal cardiovascular effects. In the present study, the effects of pentothal sodium, midazolam and midazolam-fentanyl on cardiovascular changes to endotracheal intubation during anesthetic induction were compared. Sixty patients of ASA class I or II scheduled to undergo elective operations were classified randomly into 3 groups. Group I and II were injected with thiopental sodium 5.0 mg/kg and midazolam 0.2 mg/kg, respectively. Group III received midazolam 0.1 mg/kg and fentanyl 2 ug/kg. The results were as follows ; 1) The onset time (time from intravenous injection to loss of eyelid reflex) of group III (137+/-10.29 seconds, p<0.05) was longer than those of group I (10+/-3.22 seconds) and group II (37+/-12.49 seconds). 2) The change of the mean arterial pressure : Group III showed minimal change (4% decrease, p<0.05) at 1 minute after endotracheal intubation as compared with group I (21% increase) and group II (6% increase). 3) The change of the heart rate ; Group III showed the least change (6% increase, p<0.05) at 1 minute after endotracheal intubation as compared with group I (18% increase) and group II (12% increase). From these results, it is suggested that the combined use of midazolam and fentanyl may cause less effect on the cardiovascular system during endotracheal intubation than midazolam or thiopental sodium alone.