Mutations in the envelope gene of hepatitis B virus variants co-occurring with antibody to surface antigen in sera from patients with chronic hepatitis B

Three clones of hepatitis B virus (HBV) DNA were propagated from sera of each of five patients with chronic hepatitis B who possessed hepatitis B surface antigen (HBsAg) and antibody to HBsAg in their serum. The clones were sequenced within the envelope gene (the preS1, preS2 regions and the S gene). Clones from four patients had various missense mutations involving codons 124-147 of the S-gene which encode amino acids in the loop structures that form the conformational, common antigenic determinant of HBsAg. Clones from three patients had Asn-130 (Gly in the wild-type), which generated a potential N-glycosylation site, Asn-Thr-Ser, spanning amino acids 130-132 of the S-gene product. In addition, clones from one patient had Arg-145 (Gly in the wild-type), which has been reported in escape mutants of HBV. One of the three clones from another patient had Ser-126 in place of lle or Thr in wild-type HBV, but the remaining two had no mutations known to affect expression of the common determinant of HBsAg. The remaining patient possessed HBsAg of subtype adr and anti-HBs specific for the w determinant. Clones from this patient did not reveal any mutations which are known to affect the common antigenic determinant of HBsAg.

HLA DRB1 and DQB1 alleles and haplotypes influencing the progression of hepatitis C

Some HLA class II alleles and haplotypes were examined by restriction fragment length polymorphism of corresponding DNA fragments amplified by the polymerase chain reaction in 117 patients with chronic hepatitis C in Japan. The prevalence rates were compared between patients and 1216 controls and in 67 patients with liver cirrhosis, of whom 20 had hepatocellular carcinoma and 50 patients with chronic hepatitis who did not have cirrhosis or hepatocellular carcinoma. Notably, DRB1*0405 (49% [95% confidence range 38-60%] vs. 26% [16-40%]; P < 0.05, relative risk [rr] = 2.8) and DQB1*0401 (43% [33-54%] vs. 22% [13-34%]; P < 0.05, rr = 2.1) were detected more frequently in patients with cirrhosis than in those without cirrhosis. By contrast, DRB1*0901 (11% [6-19%] vs. 28% [18-40%]; P < 0.05; rr = 0.3) and DQB1*0303 (11% [6-19%] vs. 36% [25-49%]; P < 0.01; rr = 0.2) were detected less frequently in patients with cirrhosis than those without cirrhosis. Accordingly, the DRB1*0405-DQB1*0401 haplotype was more common (43% [33-54%] vs. 22% [13-34%]; P < 0.05; rr = 2.7), while the DRB1*0901-DQB1*0303 haplotype was less common (9% [4-17%] vs. 28% [18-40%]; P < 0.05; rr = 0.3) in patients with cirrhosis than in those without cirrhosis. These results suggest that there would be HLA class II alleles and haplotypes which may be associated with an accelerated or slower progression of chronic hepatitis C towards cirrhosis and eventually to hepatocellular carcinoma.

Effect of 1,6-dihydro-2[2-(2-methylpropoxy)anilino]-6-oxo-5-pyrimidineca rboxyli c acid on ethanol-induced microvascular injury in rats

To disclose the cytoprotective mechanism of 1,6-dihydro-2[2-(2-methyoxypropoxy)anilino]-6-oxo-5-pyrimidinecarb oxylic acid (CAS 98772-05-5, MAR-99), the effect of this compound on the microvascular injury in gastric mucosa induced by 99.5% ethanol in rats was studied. In this experiment, it was found that the elevation of vascular permeability observed at the early state of ethanol-induced gastric mucosal injury was closely correlated with the combined action of histamine and slow reacting substance (leukotriene C4, LTC4). MAR-99 (0.3-10 mg/kg p.o.) prevented dose-dependently the increase in vascular permeability. Furthermore, MAR-99 (10 mg/kg p.o.) improved the decrease in the number of histamine containing cells and histamine content, and prevented the production of LTC4. These results suggest that MAR-99 exerts its anti-microvascular injury effect by regulating the release of histamine and the production of LTC4 in glandular stomach against ethanol, and this effect may contribute to the anti-lesion effect of this compound.

Amino acids and peptides. XLIV. Synthesis of stereoisomeric pentapeptides of thiol proteinase inhibitor

Stereoisomers of thiol proteinase inhibitor (TPI) were synthesized by a conventional solution method. Among them, iNoc-D-Gln-Val-Val-Ala-Ala-pNA weakly inhibited the amidolytic activity of papain, although iNoc-Gln-Val-Val-Ala-Ala-pNA inhibited papain activity fairly potently. However, the other five D-amino acid-containing peptides did not show any inhibitory effects on papain. The circular dichroism (CD) spectra of the enzyme-peptides mixtures were measured in order to study the relationship between the peptide anilides-papain interaction and the inhibitory activity.

Hepatitis C virus infection in patients with urticaria

BACKGROUND

Hepatitis C virus (HCV) infection induces variable skin manifestations.

OBJECTIVE

Our purpose was to determine whether there is an association between HCV infection and urticaria.

METHODS

Antibody to HCV (anti-HCV) and HCV genotypes were determined in patients with urticaria and in a control population.

RESULTS

Anti-HCV was detected in 19 (24%) of 79 patients with urticaria, and HCV RNA was detected in 17 (22%). Genotypes of HCV were II/1b in 12 (71%), III/2a in 4 (24%), and IV/2b in 1 (6%). The 17 patients with HCV RNA were older (53 +/- 14 vs 41 +/- 14 years, p < 0.01), and their eruption lasted longer (35% vs 6%, p < 0.05) and left pigmentation more frequently (53% vs 3%, p < 0.001). They had higher levels of alanine aminotransferase (67 +/- 34 vs 25 +/- 17 U/L, p < 0.001), aspartate aminotransferase (51 +/- 23 vs 21 +/- 8 U/L, p < 0.001), zinc turbidity test (12.8 +/- 3.1 vs 9.3 +/- 3.7 Kunkel units, p < 0.001), and IgG (1919 +/- 320 vs 1622 +/- 349 mg/100 ml, p < 0.01) than the patients without HCV RNA.

CONCLUSION

HCV could be a significant cause of urticaria. Chronic urticaria associated with HCV infection has peculiar clinical, serologic, and biochemical characteristics that could make it a distinct clinical entity with an indication for interferon therapy.

Ca2+ entry induced by calcium influx factor and its regulation by protein kinase C in rabbit neutrophils

Extracellular application of acid extract from platelet-activating factor- or thapsigargin-treated rabbit neutrophils induced a rise of cytosolic free calcium concentration ([Ca2+]i) in neutrophils and adrenal chromaffin cells suspended in Ca(2+)-containing, but not in Ca(2+)-deficient, medium. The ability of the extract to selectively induce Ca2+ entry was also confirmed by the increase in 45Ca2+ uptake and failure to stimulate Ca2+ release in digitonin-permeabilized neutrophils. 12-O-tetradecanoylphorbol-13-acetate (TPA) inhibited the extract-induced [Ca2+]i rise in a staurosporine (ST)-sensitive fashion, neither of which had any effect on its production. SK&F 96365 and econazole also reduced extract-induced Ca2+ entry. These results suggest that a Ca2+ entry-inducible substrate (calcium influx factor) is extracted from Ca2+ store-depleted neutrophils, and that its action may be regulated by protein kinase C and certain pharmacological agents.

Infection with GB virus C (GBV-C) in patients with chronic liver disease or on maintenance hemodialysis in Indonesia

RNA of a non-A to E hepatitis virus identified recently and designated provisionally GB virus C(GBV-C), was sought in patients in Indonesia by reverse-transcription polymerase chain reaction with nested primers deduced from a helicase-like region. GBV-C RNA was detected in 32 (55%) of 58 patients on maintenance hemodialysis at a frequency significantly higher (P < 0.001) than that in seven (5%) of 149 patients with chronic liver disease. Co-infection with hepatitis C virus was observed in 26 (81%) of the 32 patients on hemodialysis and in five (71%) of the seven patients with liver disease who were infected with GBV-C. Complete identity was observed in a sequence of 100 base pairs in the helicase-like region for GBV-C cDNA clones from some patients on maintenance hemodialysis. These results indicate that the patients on hemodialysis would be at high risk for GBV-C infection, which would be transmitted by transfusion and patient-to-patient routes.

Reg gene expression is increased in rat gastric enterochromaffin-like cells following water immersion stress

BACKGROUND & AIMS

Reg gene has been isolated from regenerating rat pancreatic islets, and subsequent studies have shown a trophic effect of Reg protein on islet cells. However, little is known about the role of Reg protein in the stomach. The aim of this study was to clarify the localization of Reg messenger RNA (mRNA) and its product in the stomach and to examine changes in the level of their expression during regeneration of gastric mucosal cells.

METHODS

Gastric lesions were experimentally induced in Sprague-Dawley rats by water immersion stress. Northern blot analysis and in situ hybridization studies were performed to examine changes in mRNA levels. Immunohistochemical studies were performed to identify the cellular localization and to investigate the change in Reg protein level.

RESULTS

Reg mRNA and its product were distributed in the basal part of the oxyntic mucosa and were expressed mainly in enterochromaffin-like cells. Levels of both Reg mRNA and its product were markedly increased in the water immersion-induced gastric lesions.

CONCLUSIONS

Reg mRNA and its product are expressed in gastric enterochromaffin-like cells, and their levels are increased during the healing process of water immersion-induced gastric lesions.

Infection with hepatitis GB virus C in patients on maintenance hemodialysis

BACKGROUND

A recently discovered non-A-E hepatitis virus has been designated hepatitis GB virus C (HGBV-C), but little is known about its mode of transmission and its clinical manifestations. We studied 519 patients on maintenance hemodialysis to determine whether they were infected with HGBV-C.

METHODS

HGBV-C RNA was identified in serum by a reverse-transcription-polymerase-chain-reaction assay with nested primers deduced from a non-structural region. A nucleotide sequence of 100 bp in the nonstructural region was determined on HGBV-C clones.

RESULTS

HGBV-C RNA was detected on 3.1 percent of the patients on hemodialysis (16 of 519), as compared with 0.9 percent of healthy blood donors (4 of 448, P<0.03). None of the 16 patients had evidence of active liver disease, although 7 were also infected with hepatitis C virus. Eight patients with HGBV-C infection were followed for 7 to 16 years. In two patients the virus was present at the start of hemodialysis. One had a history of transfusion, and HGBV-C persisted over a period of 16 years; the other became free of HGBV-C after 10 years. In five patients, HGBV-C RNA was first detected 3 to 20 weeks after blood transfusion and persisted for up to 13 years. One patient with no history of transfusion was infected with an HGBV-C variant with the same sequence as in two of the patients with post-transfusion HGBV-C infections.

CONCLUSIONS

Patients on maintenance hemodialysis are at increased risk for HGBV-C infection. This virus produces persistent infections, which may be transmitted by transfusions but may also be transmitted by other means.

Effect of tumor necrosis factor alpha on intrahepatic bile duct epithelial cell of rat liver

Tumor necrosis factor alpha (TNF-alpha), which is primarily produced by macrophages, is a cytokine with various biological activities. Macrophage infiltration often accompanies experimental cholangitis in rats, and chronic cholangitis in humans. The pathophysiologic significance of TNF-alpha in cholangitis is not known. We used cultured, polarized intrahepatic bile duct epithelial cells (IBDECs) from rat liver to determine whether TNF-alpha directly affects the organization of IBDEC monolayers. The addition of recombinant TNF-alpha (rTNF-alpha) to culture media at concentrations from 10 to 200 U/mL lacked cytotoxicity to the IBDECs as judged by trypan blue exclusion and lactate dehydrogenase (LDH) release. rTNF-alpha transiently reduced transepithelial electrical resistance in a dose-dependent manner. During this decrease in resistance, the cellular tight junctions became leaky, allowing horseradish peroxidase (HRP) penetration. rTNF-alpha, at concentrations up to 200 U/mL, did not detach IBDECs from Matrigel, an artificial basement membrane. Electron microscopy and immunohistochemistry for F-actin showed a well-preserved cell structure and organization of IBDECs. Results suggest that TNF-alpha is nontoxic to IBDECs, and that it increases the permeability of tight junctions. TNF-alpha may thus disturb the barrier function of the bile duct.

Molecular analysis of females manifesting thyroxine-binding globulin (TBG) deficiency: selective X-chromosome inactivation responsible for the difference between phenotype and genotype in TBG-deficient females

T4-binding globulin (TBG) is the major transport protein of thyroid hormone in man. Inherited TBG abnormalities were manifested fully in hemizygous males and partially in heterozygous females and transmitted in an X-chromosome-linked fashion, compatible with its location on Xq21-22. We have previously reported that complete deficiency (CD) and partial deficiency (PD) in Japanese subjects resulted from two distinct mutations of the TBG gene, TBG-CDJ and TBG-PDJ, respectively. Recently, we encountered a female manifesting TBG-CD and herein investigated the molecular mechanisms. She was found to possess TBG-CDJ and common-type TBG (TBG-C) alleles by characterizing the TBG gene. Then, X-chromosome inactivation status was evaluated in her family members using a phosphoglycerate kinase (PGK) gene, located on Xq13. Three TBG-CDJ heterozygotes and one unaffected female, confirmed to be PGK heterozygotes for a polymorphic BstXI site, were analyzed. Only the CD female was shown to undergo selective inactivation by examining the BstXI site in amplified products after digestion with a methylation-sensitive enzyme, HpaII. Among an additional eight informative females with TBG deficiency, one heterozygous female for TBG-PDJ shared this selective inactivation pattern. Moreover, the X-chromosome with TBG-C was suggested to be inactivated selectively from the linkage of PGK and TBG alleles recognized in eight of nine family members. Selective X-chromosome inactivation was considered to be the cause of a female heterozygous for TBG-CDJ or -PDJ manifesting the same phenotype as a hemizygote.

Amino acids and peptides. XXVIII. Preparation of poly(ethylene glycol) hybrids of Gln-Val-Val-Ala-Gly analogs and their inhibitory effect on papain

Gln-Val-Val-Ala-Gly is a sequence which is common in cysteine protease inhibitors. Poly(ethylene glycol) hybrids of Gln-Val-Val-Ala-Gly analogs were prepared by the solid phase method by fluorenylmethyloxycarbonyl chemistry. The hybrid formation of Gln-Val-Val-Ala-Gly resulted in improvement of the solubility and also in enhancement of the inhibitory effect of the peptide on papain. In addition, the hybrid formation of Gln-Val-Val-Ala-Gly analogs resulted in the enhancement of the inhibitory effect of the peptide analogs.

Infection with GB virus C in leprous patients in Japan

The detection of hepatitis C virus (HCV) in blood donors and patients with acute and chronic hepatitis has brought to the fore another virus or viruses which can be transmitted parenterally and induce liver disease. The RNA of a candidate virus designated GB virus C (GBV-C) was determined by the polymerase chain reaction with primers deduced from a helicase-like region in 229 leprous patients in Japan. GBV-C RNA was detected in 12 (5.2%) patients, and HCV RNA in 41 (18%). Three patients were coinfected with GBV-C and HCV. The nine patients infected with GBV-C alone had aminotransferase levels lower than the three patients with the mixed infection or the 38 patients infected with HCV only (P < 0.001). Sequence comparison within 100 base pairs in the helicase-like region suggested that two, three and three patients, respectively, would have been infected with three distinct strains of GBV-C. These results indicate that patients with leprosy are at increased risk for infection not only with HCV, but also with GBV-C, and that the infection with GBV-C alone would not induce hepatic injuries as severe as HCV infection.

Influence of particle size of calcium phosphate ceramics as a capping agent on the formation of a hard tissue barrier in amputated dental pulp

The purpose of this research was to compare the effect of two different particle sizes of hydroxyapatite and beta-tricalcium phosphate as capping agents on hard tissue barrier formation after experimental pulpotomy in canine dental pulp. By the thirtieth day after pulp exposure and capping with hydroxyapatite-300 (particle size, 300 microns), a hard tissue barrier was formed in 8 of 17 specimens. A newly formed barrier was seen around the hydroxyapatite particles and connecting neighboring particles. Capping with tricalcium phosphate-300 (particle size, 300 microns) led to the formation of a hard tissue barrier surrounding the particles in 11 of 17 specimens. In contrast, using hydroxyapatite-40 (particle size, 40 microns) and beta-tricalcium phosphate-40 (particle size, 40 microns), hard tissue barrier formation was poor and almost all pulp tissues showed infiltrations of inflammatory cells or abscess formation. These findings suggest that the particle size of hydroxyapatite and beta-tricalcium phosphate is an important factor in reparative hard tissue formation.

Neurofibromatosis complicated with XXX syndrome and renovascular hypertension

A 25-year-old woman with neurofibromatosis was admitted to our hospital for evaluation of hypertension. When she was 6 years old, she was diagnosed as having neurofibromatosis and XXX syndrome because of multiple café-au-lait spots, neurofibromas of the skin and mental retardation. Chromosome analysis revealed that her karyotype was 46, XX/47, XXX. Renal arteriography disclosed aneurysmal change and stenosis of the right renal artery. After right-side nephrectomy and aneurysmectomy, the kidney was autotransplanted in the left iliac fossa. Surgical procedure resulted in marked amelioration of the hypertension without medical treatment. Thus, aortorenal bypass and renal autotransplantation have emerged as the preferred revascularization operations. This is the first report of a chromosomal linkage between neurofibromatosis which is thought to be an autosomal dominant disease and the XXX syndrome.

Serum level of interleukin-4 in patients with perennial allergic rhinitis during allergen-specific immunotherapy

Interleukin-4 (IL-4) may play a central role in the IgE synthesis system, the development of Th-2-like cells, and co-ordination as well as the persistence of airway inflammatory process in allergic disorders. Therefore, IL-4 plays a key role in airway allergic disorders. This study aimed at investigating the serum concentrations of IL-4 in patients with perennial allergic rhinitis, with special reference to the possible changes and the clinical relevance following long-term immunotherapy. The study has demonstrated that the serum level of IL-4 in allergic rhinitis patients before immunotherapy is significantly higher than that in non-atopic individuals. However, the serum IL-4 level in allergic rhinitis patients did not decrease following anti-allergic medications but significantly decreased following immunotherapy. The percentage decrease in IL-4 was correlated significantly with the percentage decrease in specific IgE antibodies following long-term immunotherapy. Immunotherapy also significantly decreased specific IgE anti-bodies, but this reduction in specific IgE antibodies was not significantly correlated with the clinical improvement. In contrast, the percentage decrease in serum IL-4 was significantly correlated with the percentage decrease in symptomatic scores. The authors interpret these data to mean that immunotherapy alters T-cell cytokine profiles in the long-term, and a decline of IL-4 following immunotherapy could modulate not only production of specific IgE antibodies but also inflammatory cellular events, leading to symptomatic relief in allergic rhinitis.

Dose-dependent increases in the renal sympathetic nerve activity during rapid increase in isoflurane concentration in intact, lower airway-deafferented, and baroreceptor-deafferented rabbits

BACKGROUND

The inhalation of high concentrations of isoflurane has been reported to increase the heart rate and the concentration of serum catecholamines. Although the precise mechanisms for the sympathetic activation of isoflurane have yet to be clearly elucidated, they are considered to possibly originate from the stimulation of airway sensory afferents, the baroreceptor reflex, or the direct stimulation of the central nervous system. To determine how these three mechanisms contribute to sympathetic augmentation, the effects of lower airway deafferentation and baroreceptor deafferentation on the isoflurane-induced changes in the renal sympathetic nerve activity (RSNA) in tracheally intubated rabbits were examined.

METHODS

Twenty rabbits were given basal anesthesia. After tracheotomy and during mechanical ventilation, the changes in the heart rate, mean arterial pressure, and RSNA in response to random exposures to 1%, 2%, 3%, and 4% isoflurane were examined. The animals were assigned to one of three groups; 1, the intact group (n = 6); 2, the baroreceptor-deafferented group (n = 9), in which the sinoaortic plus vagal nerves were cut; and 3, the lower airway-deafferented group (n = 5), which underwent a bilateral vagotomy. The exposure to isoflurane was for 10 min in group 1 and 5 min in groups 2 and 3. At least 1 h was allowed for the recovery interval between exposures to isoflurane.

RESULTS

The inhalation of isoflurane caused dose-dependent increases in RSNA in all three groups. RSNA during high concentrations of isoflurane began to increase at 1 min, reaching the maximum at 4 or 5 min in group 1 (2.8- and 3.8-fold at 3% and 4% isoflurane, respectively) and group 3 (2.8- and 4.5-fold at 3% and 4% isoflurane, respectively), but it reached the peak at 2 or 3 min in group 2 (1.7- and 2.4-fold at 3% and 4% isoflurane, respectively) after the initiation of inhalation, in association with early slight increases followed by decreases of mean arterial pressure in groups 1 and 2 but only gradual decreases of mean arterial pressure in group 3. The increases in RSNA in group 3 were similar to group 1, however, those in group 2 were significantly attenuated compared with group 1.

CONCLUSIONS

The inhalation of isoflurane caused an increase of RSNA in intact, baroreceptor-deafferented, and lower airway-deafferented rabbits. The extent of the increases in RSNA was greater in intact and lower airway-deafferented rabbits than in baroreceptor-deafferented rabbits. Therefore, it is suggested that isoflurane may increase the efferent sympathetic nerve activity via the direct stimulation of the central nervous system and via the arterial baroreceptor reflex reflecting the reduction in arterial blood pressure. The stimulation of the vagally innervated airway may not contribute to the increase in the sympathetic nerve activity by isoflurane.

Influence of particle size of hydroxyapatite as a capping agent on cell proliferation of cultured fibroblasts

The influence of particle size of biomaterials on cell reaction and cell proliferation was studied by means of coculturing fibroblasts with calcium phosphate ceramics. Both dense and porous hydroxyapatite ceramics obtained under different sintering conditions were selected, and two particle sizes of 300 and 40 micrometers were used to examine cell reaction. The four materials were each cocultured with dental pulp-derived fibroblasts for 7 days. Cell reaction was observed by phase-contrast microscopy and scanning electron microscopy. Cell proliferation was measured by counting the number of trypsinized cells in 7-day-old culture. On the seventh day, the dense 300-micrometer particles of hydroxyapatite were completely covered by cultured cells that had proliferated on the dish surface. On the other hand, the porous and dense 40-micrometer particles were captured or gathered by the cultured cells, which seemed not to proliferate. The porous 300-micrometer particles were accompanied by numerous small broken pieces on the dish surface, and the cells proliferated only around the large particles. From these results, the dense 300-micrometer particles of hydroxyapatite can be considered the most appropriate biomaterial.

Fibroblasts synthesize kininogen in response to inflammatory mediators

Mouse fibroblasts in vitro secret kininogen (KGN). Rat fibroblasts also synthesized and secreted T-KGN in vitro. KGN production by these fibroblasts is greatly stimulated by dibutyryl cAMP, prostaglandin E2 and tumor necrosis factor. Human fibroblast WI-38 cells also express the L-KGN gene, which was stimulated by dibutyryl cAMP and prostaglandin E2. These results demonstrate that fibroblasts express the KGN gene, and suggest that the expression is regulated by inflammatory mediators. RT-PCR, using specific primers for the T-KGN and L-KGN genes, reveals that the rat hind-paw express both T- and L-KGN mRNAs, and the expression of both KGN mRNAs was increased in the hind-paw 24 h after inducing inflammation by injecting Freund's complete adjuvant into the paw. Thus, it is suggested that local connective tissues express the KGN gene, and that the expression is enhanced under pathological conditions, such as inflammation.