O2 uptake kinetics in response to exercise. A measure of tissue anaerobiosis in heart failure

Oxygen uptake (VO2) reflects the rate of aerobic regeneration of high-energy phosphate compounds (primarily adenosine triphosphate [ATP]). Since lactate increase is thought to result from an inadequate rate of aerobic ATP regeneration, it might be expected that lactate increase would be associated with a delayed attainment of steady state for VO2 in response to constant load exercise. Similarly if mitochondrial ATP regeneration during exercise is inadequately supported by O2 transport mechanisms, adenosine diphosphate (ADP) and purine nucleotide by-products, such as hypoxanthine, should increase. This study investigated the relationship between VO2 kinetics during exercise and accompanying changes in blood lactate and hypoxanthine values in heart failure patients, as a model of compromised O2 transport. Twenty-five patients with chronic heart failure performed cycle ergometry for 6 min at 25 W and at a work rate midway (50 percent delta) between their lactic acidosis threshold (LAT) and peak VO2. Ventilation and gas exchange were measured breath by breath, and venous lactate, hypoxanthine, norepinephrine, and epinephrine were determined at rest and 2 min after each test. The slow component of VO2 kinetics was quantified as the rise in VO2 from the third to the sixth minute of exercise (delta VO2 [6-3]). Ten age- and size-matched normal subjects served as control subjects. delta VO2 (6-3) was correlated with the increase in lactate (r = 0.71, p < 0.001), hypoxanthine (r = 0.61, p < 0.001), and norepinephrine (r = 0.41, p < 0.01) but not epinephrine in response to exercise in the heart failure patients. The delta VO2 (6-3) and delta lactate were both greater in the patients than in the control subjects at similar absolute work rates (54 +/- 20 and 60 W, respectively). However, the slope of the relationship between delta La and delta VO2 (6-3) for the patient and normal groups was indistinguishable. The lactate increase was correlated with hypoxanthine increase (r = 0.66, p < 0.001), but not norepinephrine or epinephrine. In summary, VO2 kinetics in response to exercise reflects delayed attainment of the steady state in heart failure patients, which is correlated with increases in lactate and hypoxanthine, markers of increased anaerobic metabolism.

Iron content of human 5-lipoxygenase, effects of mutations regarding conserved histidine residues

Recombinant human 5-lipoxygenase was expressed in Escherichia coli and purified to more than 95% homogeneity by ammonium sulfate precipitation and agarose-ATP column chromatography. The specific activity of the purified enzyme was 21-28 mumol/mg, as assessed by the generation of 5-hydro(pero)xyeicosatetraenoic acid. The iron content was analyzed by graphite furnace atomic absorption spectrophotometry for six preparations of the enzyme. The average value of the iron content was 0.86 mol/mol (iron/protein) with a range of 0.74-1.15 mol/mol. All lipoxygenases that have been sequenced contain 6 conserved histidine residues. Mutants of 5-lipoxygenase, with substitutions of these 6 conserved histidines, were purified and analyzed. Mutants H372Q and H550Q had no detectable enzyme activity and were also practically devoid of iron. Three mutants regarding His367 (H367Q, H367N, and H367S) were all inactive but had partial iron contents (0.5, 0.2, and 0.5 mol/mol, respectively). Finally, the mutated proteins H362Q, H390Q, and H399Q displayed reduced enzyme activity but contained similar amounts of iron as non-mutated 5-lipoxygenase. We conclude that histidines 372 and 550 constitute two of the iron ligands in 5-lipoxygenase. Also His367 is necessary for the enzyme activity, but this residue is not crucial for binding of iron.

Cysteine-dependent zinc binding by membrane proteins of Giardia lamblia

The abundant, highly variable surface proteins (VSPs) which cover the surface of Giardia lamblia trophozoites compose a group of extremely cysteine (C)-rich proteins in which more than half of the cysteines are in the motif CXXC. Because of the constancy of these features among the known VSPs and the prominence of cysteine and particularly CXXC in proteins that bind zinc and other metals, we asked whether G. lamblia VSPs bind zinc in vitro. VSPs are the major protein component of Triton X-114 detergent-phase extracts of G. lamblia trophozoites and can be readily identified by surface iodination of intact cells. The partitioning of 65Zn binding into the Triton X-114 detergent phase and the correspondence between surface iodination and zinc binding patterns of four G. lamblia strains or sublines with different VSPs support the idea that VSPs bind zinc. The requirement for renaturation of blots with a reducing agent indicates that Zn2+ is coordinated by cysteine residues, rather than by other amino acids. Binding did not appear to be specific to zinc since it was inhibited by competition with other divalent metal ions. The abundance of the VSPs and the prevalence of metal binding motifs among all known variants suggest that they may play an important role in trophozoite survival and colonization in the host.

Hepatitis B virus DNA detected by PCR in sera and liver tissues of Chinese patients with chronic liver diseases

To investigate the HBV infection and its replication in Chinese patients with chronic liver disease, polymerase chain reaction (PCR) was employed to detect hepatitis B virus DNA in sera of 410 patients with chronic liver disease and liver samples from 188 patients. The HBV DNA detectability in all serum samples was 58%. Among them 100% HBeAg-positive and 58% anti-HBe cases were HBV DNA detectable respectively. However, HBV DNA was also found in 23% HBsAg-negative/anti-HBc positive chronic cases. Furthermore, 30% anti-HBs positive chronic cases who had neutralizing antibody against HBV infection, continued to contain HBV DNA. Our findings indicate that HBV infection and its replication are dominant cause of chronic liver disease and some HBV variants may escape from the protective antibody to induce chronic liver disease, even anti-HBs antibody circulated.

Hepatitis C virus antibodies and hepatitis C virus RNA in Chinese blood donors determined by ELISA, recombinant immunoblot assay and polymerase chain reaction

Antibodies to hepatitis C virus (anti-HCV) were determined in Chinese blood donors from the city of Wuhan by a second generation ELISA screening test and a confirmatory recombinant immunoblot assay (RIBA II). Two materials of 281 and 222 sera were sampled under similar conditions in 1989 and 1990, respectively. The first collection of sera was sent to Sweden in lyophilized form, the second directly as fresh unfrozen sera. A high proportion (7.1%) of the lyophilized sera reacted positively in the anti-HCV screening assay, but only seven (2.5%) were positive by the RIBA confirmatory test. In four of these sera HCV-RNA could be detected by polymerase chain reaction (PCR) analysis. In the second material of fresh sera six reacted positively in the screening anti-HCV ELISA, but only one was RIBA positive and four were RIBA indeterminate. None of these sera was positive for HCV-RNA. Thus, the overall prevalence of anti-HCV among the 503 Chinese blood donors, as identified by RIBA, was 1.6%, and of HCV-RNA by PCR 0.8%. The confirmed antibody prevalence is higher than reported from the Western world. Caution about using data from the screening ELISA only, especially if sera have been handled in an unorthodox way, is emphasized.

[Monitoring of gentamicin blood level]

A prospective randomized comparison of blood concentration as well as manifestations of ototoxicity and nephrotoxicity in groups with conventional and individualized administration of gentamicin was carried out in a total of 106 hospitalized patients. Therapeutic serum concentrations (peak 4-9 mg/L, though less than 1 mg/L) were achieved in 50% of the patients of conventional group and in all the patients of individualized group. Incidence of auditory and renal toxic reactions was high in the conventional group, being 27% and 30% respectively, while in the individualized group, the corresponding figures were 2.8% and 0%. Therefore, individualized administration of gentamicin based on data from therapeutic drug monitoring can markedly decrease the toxic effect and increase the therapeutic efficacy. It is worthwhile to use this kind of administration clinically.

Analysis of intrahepatic HBVDNA in serologic HBV markers-negative or HBsAg-negative patients with chronic hepatitis

To explore HBV infection status in a group of serologic HBV markers-negative or HBsAg-negative patients with chronic hepatitis, in situ hybridization to hepatocellular HBVDNA was carried out in combination with detection of HBsAg and HBcAg in the liver tissues. It was found that prevalence of intrahepatic HBVDNA, HBsAg and HBcAg was 43%, 39% and 17% respectively, and 15 out of 23 cases studied were sure to bear one or more positive marker(s) of intrahepatic HBVDNA, HBsAg and HBcAg. These findings suggest that more than half of the patients with chronic hepatitis were still undergoing HBV infection, despite serologic HBV markers or HBsAg negative. Furthermore, we found that hepatocytes containing HBVDNA or surface or core antigen were often close to hepatic necrosis foci, indicating that HBV replication and its antigen(s) expression in hepatocytes could account for chronic, active and necrotic inflammation occurring in the liver of the patients mentioned above.

Hepatitis D virus infection in liver tissues of patients with hepatitis B in China

2,346 liver samples from 17 cities of China for intrahepatic hepatitis D antigen (HDAg) were studied by direct enzyme-labelled technique. HDAg was detected in 167 out of 1,764 samples of HBsAg positive individuals making a detection rate of 9.47%. Hepatitis D virus (HDV) infection existed in all the examined districts with no significant difference in the HDAg detection rate. It was found that the intrahepatic HDAg detection rate was related to the pathologic type of the liver disease. The HDAg detection rate in chronic liver diseases and severe hepatitis was higher than in other liver diseases. It suggests that HDV infection is associated with the progression and chronicity of the liver disease. Studies on the relationship between HDV infection and HBV replication showed that HBV replication might be suppressed by HDV infection. Both HDV and HBV, however, could replicate in the same hepatocyte simultaneously.

Mutagenesis of some conserved residues in human 5-lipoxygenase: effects on enzyme activity

Recombinant human 5-lipoxygenase (arachidonate:oxygen 5-oxidoreductase, EC 1.13.11.34) was expressed in Escherichia coli. In incubations of E. coli supernatants with arachidonic acid, 5-hydroxy-7,9,11,14-eicosatetraenoic acid and leukotriene A4 were formed, while incubation with 8,11,14-eicosatrienoic acid gave 8-hydroxy-9,11,14-eicosatrienoic acid. Six conserved histidine residues in 5-lipoxygenase were subjected to site-directed mutagenesis. Exchanges of His-367, -372, or -551 gave mutants for which no enzyme activities were detectable. On the other hand, exchanges of His-362, -390, or -399 gave mutants that were enzymatically active, but less so than the nonmutated control. For two of these (exchanges of His-390 or -399), the activities of the mutants were dependent on the expression temperature. Thus, the histidines in the first group (His-367, -372, -551) were crucial for 5-lipoxygenase activity, possibly because of a function of these residues as metal ligands. Mutagenesis aimed at two other conserved elements in 5-lipoxygenase, Gln-558 and the C terminus, gave mutated proteins with only a small residual activity (substitution of Gln-558), or with no detectable activity (deletion of six C-terminal amino acids), indicating that these regions are important for the function of 5-lipoxygenase.

[Lipoprotein (alpha) as a risk factor for myocardial infarction]

Serum lipoprotein (alpha) [Lp(alpha)]was determined in 105 cases of myocardial infarction survivors (MIS). Lp(alpha) level in MIS was much more elevated as compared with that in healthy subjects and in a hypertension group. Lp(alpha) had no relation with apolipoprotein B and AI, cholesterol, triglyceride and high density lipoprotein cholesterol. It may be a significant and independent risk factor for coronary heart disease.

[Investigation of anti-hepatitis C virus antibody in healthy blood donors in China: enzyme immunoassay and recombinant immunoblot]

281 serum samples from Chinese healthy blood donors (HBsAg negative and ALT normal) were tested for anti-HCV antibodies with ortho-HCV ELISA test system and Abbott HCV EIA diagnostic kits. The results were further confirmed with recombinant immunoblot assay (RIBA). Our research showed that the prevalence of anti-HCV antibody in this group was 2.1% (6/281), being higher than that in other countries and regions. It indicated that great attention should be paid to HCV infection in China. The reason of dark groundback and high false positive reactivity produced by the ELISA was discussed. So, the positive reactivity produced by ELISA should be confirmed by other specific method such as RIBA. Reexamination of the 281 serum samples with HBsAg AUSRIA II showed that HBsAg was positive in 7 and HBVDNA positive in one of them.

Production of the glycosylphosphatidylinositol-specific phospholipase D by the islets of Langerhans

A large number of diverse cell surface proteins are anchored to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. One proposed function for the GPI anchor is that it facilitates the release of the protein from the cell by acting as a target for anchor-specific phospholipases. We and others have discovered that mammalian plasma contains a GPI-specific phospholipase D (GPI-PLD) (Cardoso de Almeida, M. L., Turner, M. J., Stambuk, B. V., and Schenkman, S. (1988) Biochem, Biophys. Res. Commun. 150, 476-482; Davitz, M. A., Hereld, D., Shak, S., Krakow, J., Englund, P. T., and Nussenzweig, V. (1987) Science 238, 81-84; Low, M. G., and Prasad, A. R. S. (1988) Proc. Natl. Acad. Sci. U. S. A. 85, 980-984). Because the GPI-PLD recognizes a conserved portion of the anchor, all GPI-anchored proteins are potential substrates for the enzyme. We demonstrate in this communication the production of the plasma GPI-PLD by the islets of Langerhans. GPI-PLD enzymatic activity was found in dog pancreatic microsomes, but not pancreatic juice. Both the pancreatic and plasma enzymes were divalent cation-dependent and had identical substrate specificities. Purified murine islets of Langerhans, as well as alpha and beta cells, contained and released GPI-PLD activity. A GPI-PLD DNA fragment was amplified by polymerase chain reaction from a normal human islet cDNA library; the amplified fragment hybridized with the GPI-PLD cDNA clone. These findings represent the first demonstration of the production of the plasma GPI-PLD by a specific tissue site as well as cell type.

[Clinical evaluation of enoxacin]

436 patients with various infections were treated with 2 kinds of enoxacin preparations, tablets in 336 cases and capsules in 100 cases. The total effective rate for tablets and capsules was 97.0% and 95.0% respectively. The bacterial eradication rate was 96.8% for tablets and 96.7% for capsules. Adverse reactions were few and mild. A randomized study of enoxacin and norfloxacin in the treatment of 209 patients with enteric and urinary infections was carried out simultaneously, the effective rate of enoxacin (99.1%) was similar to norfloxacin (95.0%). The incidence of side effects in norfloxacin group was slightly higher than that in enoxacin (P less than 0.05).

The role of fitness on VO2 and VCO2 kinetics in response to proportional step increases in work rate

The purpose of this study was to determine the effect of fitness and work level on the O2 uptake and CO2 output kinetics when the increase in work rate step is adjusted to the subject's maximum work capacity. Nine normal male subjects performed progressive incremental cycle ergometer exercise tests in 3-min steps to their maximum tolerance. The work rate step size was selected so that the symptom-limited maximum work rate would be reached in four steps at 12 min in all subjects. Oxygen consumption (VO2) and carbon dioxide production (VCO2) were calculated breath by breath. For the group, the time (mean, SEM) to reach 75% of the 3-min response (T0.75) for VO2 increased significantly (P less than 0.01) at progressively higher work rate steps, being 53.3 (5.5) s, 63.5 (4.6) s, 79.5 (5.0) s, and 94.5 (5.8) s, respectively. In contrast, T0.75 for VCO2 did not change significantly [74.9 (7.4) s, 75.6 (5.0) s, 85.1 (5.3) s, and 89.4 (6.3) s, respectively]. VCO2 kinetics were slower than VO2 kinetics at the low fractions of the subjects' work capacities but were the same or faster at the high fractions because of the slowing of VO2 kinetics. The first step showed the fastest rise in VO2. While VO2 kinetics slowed at each step, they were faster at each fraction of the work capacity in the fitter subjects. The step pattern in VO2 disappeared at high work rates for the less fit subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of exercise testing protocol on parameters of aerobic function

Four different patterns of increasing work rate (ramp and 1-min, 2-min, and 3-min steps) to maximum tolerance were studied in eight normal male subjects during cycle ergometer exercise testing to determine the effect of the work rate protocol on the parameters of aerobic function. The overall rate of work rate increase was kept constant. Measurements included VO2max, anaerobic threshold (AT), and the O2 uptake increase with respect to work rate increase (delta VO2/delta WR). VO2, VCO2, VE, respiratory exchange ratio (R), PETCO2, and PETO2 were calculated breath-by-breath. No significant difference was found in VO2max, AT, AT/VO2max, and delta VO2/delta WR among the four work rate protocols. Other measurements such as total work, maximal work rate, VCO2, VE, R, HR, O2 pulse, and the VO2 at which VE increases disproportionately to VCO2 (ventilatory compensation point) were also similar among the four protocols. Both the ramp and 1-min step work rate tests had no step pattern in either VO2 or VCO2, and the step pattern for the 2-min and 3-min step tests was attenuated or disappeared at work rates above AT. We conclude that the parameters of aerobic function, and other physiological responses at maximum work rate, were independent of the pattern of work rate increase, provided that the overall rate of work rate increase was the same.

Comparison of pre-S1 and pre-S2 proteins in hepatocytes with replication by in situ hybridization assay

To compare the relationship of pre-S1 and pre-S2 proteins in hepatocytes with HBV replication, HBVDNA in situ hybridization was performed for a group of patients with chronic hepatitis by bio-probe, in conjunction with detection of intrahepatic HBsAg, HBcAg, pre-S1 and-S2 antigens. It was found that the expression of intrahepatic pre-s1 and pre-S2 proteins was visualized as cytoplasmic homogeneous and inclusion types, on some occasions as membranous localization. However, the positive rate for pre-S1 protein was up to 75% (15/20), being significantly higher than that of pre-S2 protein (35%; 7/20) in the same group (P less than 0.05). What in more important, the pre-S1 expression, rather than pre-s2, was in parallel with the presence of intrahepatic HBVDNA and HbcAg. All these findings suggest that the pre-S1 protein might be mainly expressed at the HBV replication phase, thus, to some extent, the detection of pre-S1 protein might complement HBe system and HBVDNA clinical routine.

The cytoplasmic HBVDNA implication: HBV replication or non-replicative status

Intrahepatocellular HBVDNA was investigated in patients with chronic hepatitis B by in situ hybridization assay, employing biotin-labelled HBVDNA as the specific probe. It was found that HBVDNA was predominantly present in the cytoplasm of hepatocytes. In general the cases with cytoplasmic HBVDNA could be grouped as follows: 1) cytoplasmic HBVDNA coinciding with intrahepatic envelope protein and nucleocapsid component expression, this pattern of the cytoplasmic HBVDNA would be replicative; 2) cytoplasmic HBVDNA accompanied by intrahepatic single HBsAg expression, common to HBVDNA integrated into host genome with only HBsAg being found frequently in liver; 3) with only cytoplasmic HBVDNA, with neither HBsAg nor HBcAg expression, representative for non-replicative status. It is speculated that the reason for the occurrence of the cytoplasmic hybridization signal in cases with non-replicative HBVDNA may be due to DNA-RNA transcript hybrid. The prudent way to evaluate the implication of the cytoplasmic HBVDNA is to consider the combination of HBVDNA location, intrahepatic gene product expression, and HBV markers in the serum.

A study on hepatitis D virus infection in liver tissues of patients with hepatitis B in China

2346 liver samples from 17 areas in China were investigated for intrahepatic hepatitis D antigen (HDAg) by direct enzyme-labelled technique. HDAg was detected in 167 out of 1764 samples of HBsAg positive individuals with the detection rate of 9.47%. Hepatitis D virus (HDV) infection existed in all the examined areas without any significant difference regarding HDAg detection rate. A relationship of intrahepatic HDAg to the pathologic type of the liver disease was observed. The HDAg detection rate in chronic liver diseases and severe hepatitis was higher than in other liver diseases. It suggested that HDV infection was associated with the progression and chronicity of the liver disease. Studies on the relationship between HDV infection and HBV replication showed that HBV replication might be suppressed by HDV infection. Both HDV and HBV, however, could replicate in the same hepatocyte simultaneously.

Etiology of acute exacerbation in patients with severe chronic active hepatitis by in situ HBVDNA hybridization technique

To explore etiology of acute exacerbation in severe chronic active hepatitis, in situ HBVDNA hybridization was carried out combined with detection of HBV markers in the serum and the liver as well as intrahepatic HDAg in 15 cases. Four subgroups were identified based on the etiological evidence: 1) 9 cases were still undergoing HBV active replication or reactivation with cytoplasmic and membraneous HBcAg expression, often associated with the hepatic necrosis foci; 2) 3 cases showed HBsAg or/and HBVDNA positivity despite absence of HBcAg expression, the membranous and homogeneous HBsAg expression being closely related with hepatic necrosis; 3) 2 cases were HDAg positive; 4) the remaining case exhibited no HBV infection evidence. All findings suggested that HBV active replication or reactivation was the major cause of the exacerbation in severe chronic active hepatitis. In addition, HBV superinfection accounted for over 10% of cases with acute exacerbation. Hepatitis A or C may contribute to some episodes of exacerbation.

Intrahepatic HBVDNA replication and gene products expression correlated with foci of hepatic necrosis

Intrahepatic HBVDNA of patients with chronic hepatitis B was detected by in situ cytohybridization assay in combination with demonstration of HBsAg and HBcAg expression, and correlated with the foci of hepatic necrosis. It was found that HBsAg and HBcAg expressing sites appeared in the same areas where HBVDNA replicated; when HBsAg and HBcAg simultaneously expressed in the liver, one antigen usually dominated, the other declined. This unbalanced expression may be caused by the gene or transcripts variance which encodes the surface or core antigen, or by the activity of each replication. The other observation is that HBVDNA-positive hepatocytes outnumbered liver cells containing HBsAg and HBcAg in a few cases. It is supposed that a part of cytoplasmic HBVDNA was on replicative phase with gene production expression, on the contrary, another part of cytoplasmic HBVDNA may be out of replication with no gene product expression during chronic hepatitis B. Finally HBsAg and HBcAg expressing sites corresponding to HBVDNA-positive hepatocytes were closely attached to the foci of hepatic necrosis. There was no significant difference in the frequency of HBsAg and HBcAg expression correlating to hepatic necrosis.

Investigation of HBV infection status in anti-HBe Chinese patients with chronic hepatitis by in situ hybridization assay

To investigate HBV infection in anti-HBe positive Chinese patients with chronic hepatitis, demonstration of intrahepatocellular HBV-DNA was performed by in situ hybridization technique, coupled with detection of intrahepatic HBcAg and HBsAg. Based on the presence or absence of HBV-DNA, HBcAg and HBsAg of 15 cases, three subgroups were identified: 1) 4 cases with HBV active replication characterized by intrahepatic HBV-DNA, HBcAg and HBsAg copositive; 2) 8 cases with HBV incomplete replication or antigen expression defined as positivity of both intrahepatic HBV-DNA and HBsAg; 3) 3 cases with HBV inactive replication described as absence of intrahepatic HBV-DNA, HBcAg and HBsAg. All findings strongly suggest that different HBV infection status could be distinguished among Chinese patients with seroconversion from HBeAg to anti-HBe positivity: a small number of cases had stopped replication; but part of the cases was still undergoing HBV active replication; on the other hand, HBV infection status in half of the remaining cases seemed to stay in an intermediate phase from active virus replication to inactive replication.

Reconstitution of translocation-competent membrane vesicles from detergent-solubilized dog pancreas rough microsomes

Dog pancreas rough microsomes were solubilized in 1% octyl beta-glucoside, and membrane vesicles were reconstituted by slow 30-fold dilution with a buffer of low ionic strength. Asymmetric assembly of the membranes occurred during reconstitution since the vesicles formed contained ribosomes bound only to the vesicular outer surfaces. The reconstituted vesicles were similar in protein composition to native rough microsomes, although these vesicles were largely devoid of luminal-content proteins. These reconstituted vesicles could translocate and process nascent secretory (human placental lactogen) and membrane proteins (influenza hemagglutinin and rat liver ribophorin I) synthesized in cell-free translation systems programmed with the corresponding mRNAs. Signal cleavage and N-glycosylation only occurred when the reconstituted membranes were present during translation, providing evidence that the translocation apparatus was asymmetrically assembled into the reconstituted membranes. When a supernatant lacking ribosomes and particles greater than 50S from centrifuging the detergent-solubilized microsomes at high speed was used for reconstitution, smooth-surfaced membrane vesicles were obtained that, except for the absence of ribosomal proteins, were similar in protein composition to that of the reconstituted vesicles from total solubilized rough microsomes. The reconstituted smooth-surfaced vesicles, however, were totally inactive in cotranslational processing and translocation of nascent polypeptides. These findings suggest that ribosomes and/or large macromolecular complexes, not dissociated under our solubilization conditions, are essential for in vitro assembly of a functional translocation apparatus.

Intrahepatic expression of pre-S proteins of hepatitis B virus and its possible relation to liver cell necrosis

To assess the significance of intrahepatic expression of pre-S1 and S2 proteins of hepatitis B virus (HBV) in patients with HBV infection, an indirect immunoperoxidase technique employed monoclonal antibodies to pre-S proteins was used to detect pre-S1 and -S2 proteins in 80 liver specimens. The frequency of pre-S1 and -S2 proteins was 61.3% and 51.3%, respectively, and the co-expression of pre-S and HBsAg occurred in most specimens. The preferential expression of pre-S1 and -S2 in HBcAg-positive specimens suggests that pre-S proteins are associated with HBV replication. Membranous expression of both pre-S1 and -S2 is associated with inflammatory activity and liver cell necrosis. Furthermore, our results show that T cells, not NK or B cells, were the predominantly infiltrating cells in necrotic foci with pre-S expression. Almost all of these T cells may express HLA-DR antigen simultaneously; therefore, they are activated. In conjunction with these data, we conclude that, as the essential components of HBV envelope proteins, pre-S proteins may play an important role in resulting in liver cell necrosis.

Morphology, distribution and its significance of intrahepatic HBV DNA in liver disease: a study by in situ hybridization

A biotin-labeled DNA probe specific for hepatitis B virus (HBV) nucleotide sequences was hybridized in situ to liver tissue of 129 cases with liver disease. It was found that HBV DNA was predominantly visualized in cytoplasm of hepatocytes in three patterns: cytoplasmic compact, discrete and inclusion pattern. Its distribution in parenchyma in the sections of specimens may be defined as lobular, focal and spotty. The detection of intrahepatic HBV DNA depended on two factors, at least in the present study: 1) liver disease activity; chronic active hepatitis (CAH) group had a significant higher prevalence (81%) as compared to cirrhosis, chronic lobular hepatitis (CLH), acute hepatitis and hepatocellular carcinoma (HCC) groups; 2) HBV infection state: HBV DNA was more easily detected in HBeAg positive or intrahepatic HBcAg positive patients than in single HBsAg positive or anti-HBc cases. The findings that hepatocytes expressing HBV DNA, particularly in focal distribution, were closely related to hepatic necrosis sites suggested that HBV replication might occur in conjunction with hepatic necrosis.