[Screening results and genetic analysis of neonatal tetrahydrobiopterin deficiency in Hainan Province from 2007 to 2019]

A total of 1 295 516 dried blood spots were collected from newborns in Hainan Province from 2007 to 2019 who participated in the screening of neonatal diseases, and 43 cases of hyperphenylalaninemia were diagnosed. Among the 43 cases, 8 cases were confirmed to have tetrahydrobiopterin deficiency (4 males and 4 females). The incidence of tetrahydrobiopterin deficiency among newborns in Hainan Province was 6.2/1 million. Six mutations in the PTS gene were detected among 7 cases; the mutations were as follows: c.317C>T, c.286G>A, c.259C>T, c.155A>G, c.84+291A>G and c.83+1777T>G. A homozygous mutation at c.41T>C site of QDPR gene was detected in one case. Overall, it's found that the incidence of tetrahydrobiopterin deficiency in newborn populations in Hainan Province is low, and PTS gene mutations account for the largest proportion of cases of tetrahydrobiopterin deficiency within the study population.

ATP-mediated protein kinase B Akt/mammalian target of rapamycin mTOR/p70 ribosomal S6 protein p70S6 kinase signaling pathway activation promotes improvement of locomotor function after spinal cord injury in rats

The protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/p70 ribosomal S6 protein kinase (p70S6K) signaling pathway, as a central controller of cell growth, proliferation, survival, and differentiation in response to extracellular signals, growth factors, nutrient availability, energy status of the cell, and stress, has recently gained attention in neuroscience. The effects of this signaling pathway on repair of spinal cord injury (SCI), however, have not been well elucidated. ATP is increasingly recognized as an important regulator of signal transduction pathways, and plays important roles in functional recovery after nervous system injury. In the present study, we examined the ATP-induced changes of the Akt/mTOR/p70S6K signaling pathway in injured spinal cord of adult rats and potential therapeutic effects of this pathway on SCI-induced locomotor dysfunction. SCI was produced by extradural weight-drop using modified Allen's stall with damage energy of 50 g-cm force. The rats were divided into four groups: SCI plus ATP, SCI plus saline, SCI plus ATP and rapamycin, and sham-operated. Using immunostaining studies, Western blot analyses and real-time qualitative RT-PCR analyses, we demonstrated that the Akt/mTOR/p70S6K signaling pathway is present in the injured spinal cord and the expression of its components at the protein and mRNA levels is significantly elevated by exogenous administration of ATP following SCI. We observed the effectiveness of the activated Akt/mTOR/p70S6K signaling pathway in improving locomotor recovery, significantly increasing the expression of nestin, neuronal nuclei (NeuN), neuron specific enolase (NSE), and neurofilament 200 (NF200), and relatively inhibiting excessive reactive astrogliosis after SCI in a rapamycin-sensitive manner. We concluded that ATP injection produced a significant activation of the Akt/mTOR/p70S6K signaling pathway in the injured spinal cord and that enhancement of rapamycin-sensitive signaling produces beneficial effects on SCI-induced motor function defects and repair potential. We suggest that modulation of this protein kinase signaling pathway activity should be considered as a potential therapeutic strategy for SCI.

Gene expression profile of transgenic mouse kidney reveals pathogenesis of hepatitis B virus associated nephropathy

Hepatitis B virus (HBV)-associated nephritis has been reported worldwide. Immune complex deposition has been accepted as its pathogenesis, although the association between the presence of local HBV DNA and viral antigen and the development of nephritis remains controversial. To understand better the roles played by HBV protein expression in the kidney, the global gene expression profile was studied in the kidney tissue of a lineage of HBV transgenic mouse (#59). The mice expressed HBsAg in serum, and HBsAg and HBcAg in liver and kidney, but without virus replication. Full-length HBV genome (adr subtype, C genotype) isolated from a chronic HBV carrier was used to establish the transgenic mice #59. Similarly manipulated mice that did not express HBV viral antigens served as controls. Southern blotting, hybridization with HBV probe, and immuno-histochemical staining were used to study HBV gene expression. mRNA extracted from the kidney tissue was analyzed using Affymetrix microarrays. HBsAg and HBcAg were located mainly in the cytoplasm of tubular epithelium. Altogether 520 genes were "up-regulated" more than twofold and 76 genes "down-regulated" more than twofold in the kidney. The complement activation, blood coagulation, and acute-phase response genes were markedly "up-regulated". Compared to the controls, the level of serum C3 protein was decreased in #59 mice, while the level of C3 protein from kidney extract was increased. Results indicate that expression of HBsAg and HBcAg in tubular epithelial cells of the kidney per se can up-regulate complement-mediated inflammatory gene pathways, in addition to immune complex formation.

Selective functional deficit in dendritic cell--T cell interaction is a crucial mechanism in chronic hepatitis B virus infection

A defect in specific T cell immunity has long been assumed to be the central mechanism of persistent Hepatitis B virus (HBV) infection. Recent studies on HBV transgenic mice have suggested, however, that functional deficit of dendritic cells (DC) was an underlying cause for the T cell dysfunction. The functions of monocyte-derived DC were determined by studying 75 subjects that included chronic hepatitis B patients with low or high HBV load; antibody to hepatitis B surface antigen (anti-HBs) positive individuals who had recovered completely from previous acute HBV infection; healthy donors who had received hepatitis B vaccination and were anti-HBs positive; and immunologically naïve to HBV or the vaccine individual. Impaired interactions between monocyte-derived DC and T cells were shown in chronic HBV infection patients, especially in those with active virus replication. The dysfunctions included: (i) failure of DC to increase human leukocyte antigen (HLA-II), B7 expression and interleukin-12 secretion in responses to hepatitis B surface antigen (HBsAg), (ii) defective induction of T cell proliferative response to HBsAg, (iii) failure to activate T cells to produce cytokines and (iv) deficit in the induction of antigen specific cytotoxic T lymphocytes (CTLs). In vitro treatment of DC with tumour necrosis factor-alpha improved HLA-II and B7 expression, as well as Th cell and CTL responses. It is concluded that defective DC-T cell interactions may account for the specific T cell immune defects in chronic HBV infection. Immunotherapy that aims at restoring DC functions could offer a new opportunity for effectively managing persistent HBV infections.

Comparing the immunogenicity of hepatitis B virus S gene variants by DNA immunization

DNA immunization was used to compare the immunogenicity of hepatitis B virus S gene variants. Four recombinant plasmid DNAs containing the full-length virus genome with different S gene inserts were used to immunize BALB/c and C57/BL/6 mice. These inserts were cloned from 129L (residue 129, glutamine to leucine), 129H (residue 129, glutamine to histidine) 145R (residue 145, glycine to arginine) variants and the wild-type virus. The titer of hepatitis B virus core antibodies (anti-HBc) in immunized mice was used as the control for the efficiency of DNA immunization. Serum hepatitis B surface antibody (anti-HBs) titer and cytokines induced in splenocytes stimulated with hepatitis B surface antigen (HBsAg) were monitored as specific immune responses induced by different plasmid DNAs. 129L DNA induced significantly lower anti-HBs antibodies (IgG, IgG1, and IgG2a) and less interferon-gamma, compared to those in mice immunized with the 129H variant and the wild-type HBV DNA (p < 0.05). Computer modeling showed that a change from glutamine to leucine at 129 residue led to higher hydrophobicity and could result in decreased immunogenicity. Results indicate that DNA immunization can be used to compare the humoral and cellular immunogenicity among different HBV S variants.

A single amino acid in the reverse transcriptase domain of hepatitis B virus affects virus replication efficiency

To explore functional domains in the hepatitis B virus (HBV) polymerase, two naturally occurring HBV isolates (56 and 2-18) with 98.7% nucleic acid sequence homology but different replication efficiencies were studied. After transfection into HepG2 cells, HBV DNA isolated from intracellular virus core particles was much higher in 56-transfected cells than in cells transfected with 2-18. The structural basis for the difference in replication efficiency between these two isolates was studied by functional domain gene substitution. The complete polymerase (P) gene and its gene segments coding for the terminal protein (TP), spacer (SP), reverse transcriptase (RT), and RNase H in 2-18 were separately replaced with their counterparts from 56 to construct full-length chimeric genomes. Cell transfection analysis revealed that substitution of the complete P gene of 2-18 with the P gene from 56 slightly enhanced viral replication. The only chimeric genome that regained the high replication efficiency of the original 56 isolate was the one with substitution of the RT gene of 2-18 with that from 56. Within the RT region, amino acid differences between isolates 2-18 and 56 were located at positions 617 (methionine versus leucine), 652 (serine versus proline), and 682 (valine versus leucine). Point mutation identified amino acid 652 as being responsible for the difference in replication efficiency. Homologous modeling studies of the HBV RT domain suggest that the mutation of residue 652 from proline to serine might affect the conformation of HBV RT which interacts with the template-primer, leading to impaired polymerase activity.

Laboratory diagnosis of viral hepatitis in China: the present and the future

Viral hepatitis is one of the most prevalent infectious diseases in China. To date, all five types, hepatitis A, B, C, D and E have been reported in China, and the incidences of all these types are high in the Chinese population. Serological tests are mainly used for the diagnosis of hepatitis A, B, C and E in patients, epidemiological surveys and for efficacy studies of vaccines. Currently, nucleic acid-based assays are only used in research and for evaluation of antiviral and immuno-therapies.

[Persistent microbial infection and therapeutic vaccine]

Microbial persistent infection usually occurs due to invasion of the immune system, microbial genomic mutation or integration of microbial DNA with host chromosomal DNA. Defective host immune responses or immune tolerance are also related to persistent infection. Therapeutic vaccine is aimed at inducing specific humoral and cellular immune responses to terminate microbial persistent infection or to prevent progression of diseases. Different categories of therapeutic vaccines have been presented and the prospect of research as well as the development of novel effective therapeutic vaccines are discussed.

Full-length genomic analysis of hepatitis B virus isolates in a patient progressing from hepatitis to hepatocellular carcinoma

In hepatitis B virus (HBV)-endemic countries, the majority of hepatocellular carcinoma (HCC) arises in HBV carriers. High frequency of mutations at nucleotides 1762(A-->T) and 1764(G-->A) in the core promoter region have been described in HCC. Due to the differences in genetic backgrounds, environmental risk factors and random cellular insertion sites, it is difficult to analyze the possible roles of HBV variants detected in different HCC patients. In a follow-up cohort study, an HBsAg-positive asymptomatic carrier was diagnosed HCC within 4 years. Eleven full-length HBV isolates, three from the first serum sample obtained 4 years pre-HCC, and eight from serum sample, peri-tumor and tumor tissue post-HCC of this individual were sequenced and used to transfect HepG2 cells. When sequences were compared between pre- and post-HCC isolates, no single mutation common to all post-HCC isolates that differed from pre-HCC isolates was found. Among all 11 isolates, there were 20 predicted amino acid substitutions shared by two or more post-HCC isolates. These were located in the S(5), X(4), core(4), polymerase(4), pre-S1(2) and pre-S2(1) proteins. Possible roles of amino acid substitutions and enhanced replication efficiency in cells transfected by post-HCC isolates are discussed.

Therapeutic efficacy of hepatitis B surface antigen-antibodies-recombinant DNA composite in HBsAg transgenic mice

Therapeutic efficacy of HBsAg-anti-HBs-recombinant DNA harboring hepatitis B virus (HBV) S gene complex was compared with three other therapeutic vaccine candidates (recombinant HBsAg, HBsAg complexed to anti-HBs antibodies and naked plasmid DNA encoding the HBV S gene). After four injections at 3-week intervals, the most pronounced decrease of serum HBsAg, the highest titer of anti-HBs response, the highest level of interferon-gamma produced by splenocytes and potent cytotoxicity T cell response were observed in the HBsAg-anti HBs-sDNA immunized group. Reduced expression of HBsAg in hepatocytes was also shown. The therapeutic mechanism of HBsAg-anti-HBs-DNA was speculated as modulation of HBsAg presentation via both endogenous and exogenous pathways.

Full-length genomic analysis of hepatitis B virus isolates in a patient progressing from hepatitis to hepatocellular carcinoma

In hepatitis B virus (HBV)-endemic countries, the majority of hepatocellular carcinoma (HCC) arises in HBV carriers. High frequency of mutations at nucleotides 1762(A-->T) and 1764(G-->A) in the core promoter region have been described in HCC. Due to the differences in genetic backgrounds, environmental risk factors and random cellular insertion sites, it is difficult to analyze the possible roles of HBV variants detected in different HCC patients. In a follow-up cohort study, an HBsAg-positive asymptomatic carrier was diagnosed HCC within 4 years. Eleven full-length HBV isolates, three from the first serum sample obtained 4 years pre-HCC, and eight from serum sample, peri-tumor and tumor tissue post-HCC of this individual were sequenced and used to transfect HepG2 cells. When sequences were compared between pre- and post-HCC isolates, no single mutation common to all post-HCC isolates that differed from pre-HCC isolates was found. Among all 11 isolates, there were 20 predicted amino acid substitutions shared by two or more post-HCC isolates. These were located in the S(5), X(4), core(4), polymerase(4), pre-S1(2) and pre-S2(1) proteins. Possible roles of amino acid substitutions and enhanced replication efficiency in cells transfected by post-HCC isolates are discussed.

Detection of HPV in Japanese and Chinese oral carcinomas by in situ PCR

Human papillomavirus (HPV) is established as the cause of almost 100% of cervical carcinomas. However, the association of HPV with oral squamous cell carcinomas (SCCs) is less well understood. We examined the prevalence of HPV in oral SCCs in samples of Japanese and Chinese populations. Using in situ polymerase chain reaction (PCR) analysis (MY09 and MY11 consensus primers), HPV was detected in the nucleus of epithelia and tumor cells in oral lesions. Analysis revealed the specific presence of HPV DNA in all cases of SCC in our Japanese (10/10) and Chinese (10/10) population samples. These results suggest that HPV infection could be one of several risk factors contributing to oral SCC in Japanese and Chinese.

Cloning and Expression of Chinese Duck Interferon-gamma Gene

The efficacy of cytokine therapy has been demonstrated in several viral diseases. Interferon-gamma is a cytokine that has potent antiviral property and immunomodulatory activity. To investigate the role of IFN-gamma in viral clearance during natural infection and to define the antiviral mechanism, DHBV-infected ducks was used as an animal model. To clone, express, and develop the method of quantifying DuIFN-gamma gene transcription and expression, DuIFN -gamma cDNA was amplified by RT-PCR from PHA stimulated duck PBMC. Recombinant plasmid expressing DuIFN-gamma was used to transfect COS-7, and the cell culture supernatant was analyzed by CPE inhibitory assay and MTT methods to determine the antiviral titer of IFN-gamma. The GST-DuIFN-gamma fusion protein was expressed in E.coli and purified using the GST sepharose 4B. Results indicated that the supernatant collected from COS-7 cells transfected with DuIFN-gamma cDNA was able to prevent duck fibroblasts from VSV induced CPE in a dose dependent manner. An anti-DuIFN-gamma antibody neutralized this antiviral activity.

Antigen-antibody complex as therapeutic vaccine for viral hepatitis B

In a previous study, hepatitis B surface antigen (HBsAg) complexed to human anti-HBs immunoglobulins (HBIG) in excess of HBsAg was used as therapeutic vaccine to treat chronic hepatitis B patients and promising results were obtained. To study the mechanisms of this approach, mice were immunized with HBsAg or IC (immunogenic complex, i.e. HBsAg complexed with mouse polyclonal anti-HBs). Studies indicate that IC induced enhanced immune responses by increasing uptake of HBsAg through Fc receptors on antigen presenting cells and modulated HBsAg processing and presentation. This modulation led to stimulation of T cell responses, and increased production of IL-2 and IFN-gamma. Assay for antibody subclasses showed that higher ratio of IgG 2a was observed in the IC immunized group, which correlated with the production of lymphokine pattern. When alum was used as the adjuvant, though antibody response was enhanced, production of cytokines decreased. When DNA from a recombinant plasmid was added to IC as an adjuvant, the titer of anti-HBs was significantly higher than those in mice immunized only with the DNA or the IC. Since DNA immunization can induce both cellular and humoral immune responses, combined immunization using IC and DNA might serve as another type of therapeutic vaccine for viral hepatitis B.

A novel hepatitis B virus variant S 129 (Gln-->Leu): lack of correlation between antigenicity and immunogenicity

A point mutation has been detected in the "a" determinant of hepatitis B surface antigen (HBsAg) in an infant immunised with hepatitis B vaccine after exposure to hepatitis B virus (HBV). This A-to-T point mutation at nucleotide 540 resulted in a glutamine-to-leucine substitution at amino acid residue 129 (129L). The S gene fragment (nucleotide 58-1072) of this isolate was cloned and used to substitute the wild-type S gene in a plasmid (p3.8II), containing 1.2 copy of full-length HBV genome with expression and replication efficiency. This plasmid p3.8II-129L was used to transfect HepG2 cells. HBsAg expressed by p3.8II-129L showed higher binding efficiency compared with the original plasmid containing the wild-type clone. A panel of 24 anti-HBs monoclonal antibodies (MAbs) was used to characterise the binding efficiency of HBsAg expressed by p3.8II-129L. Eighteen showed higher binding to the antigen, whereas HBsAg expressed by p3.8II-145R gave a consistently lower absorbance or were negative. Surprisingly, when the immunogenicity of plasmid constructs was used for DNA immunisation in Balb/c mice, the anti-HBs response induced by p3.8II-129L was significantly lower than that of the wild-type p3.8II. The lack of correlation between the antigenicity profile (binding of expressed HBsAg to anti-HBs in vitro), and the immunogenicity (induction of anti-HBs by plasmid DNA in vivo) of HBsAg with leucine substitution at position 129 indicates that biological characteristics other than the binding efficiency of HBsAg to anti-HBs could occur in HBsAg variants. These different aspects of the biological characteristics of S mutants merit further investigation.

[Application of repairing tibia and soft tissue defect with free fibula combined tissue grafting]

OBJECTIVE

To investigate a good method for repairing the long bone defect of tibia combined with soft tissue defect.

METHODS

From 1988-1998, sixteen patients with long bone defect of tibia were admitted. There were 12 males, 4 females and aged from 16 to 45 years. The length of tibia defect ranged from 7 cm to 12 cm, the area of soft tissue defect ranged from 5 cm x 3 cm to 12 cm x 6 cm. Free fibula grafting was adopted in repairing. During operation, the two ends of fibular artery were anastomosised with the anterior tibial artery of the recipient, and the composited fibular flap were transplanted.

RESULTS

All grafted fibula unioned and the flap survived completely. Followed up for 6 to 111 months, 14 patients acquired the normal function while the other 2 patients received arthrodesis of the tibial-talus joint. In all the 16 patients, the unstable ankle joint could not be observed.

CONCLUSION

The modified method is characterized by the clear anatomy, the less blood loss and the reduced operation time. Meanwhile, the blood supply of the grafted fibula can be monitored.

Immunization against hepatitis B virus by mucosal administration of antigen-antibody complexes

Antigen-antibody complexes have been shown to enhance immune responses against several antigens given by parenteral immunization. Herein, we have evaluated the potential of administering such immunostimulatory complexes by a mucosal route. Hepatitis B surface antigen (HBsAg) complexed with antibodies against HBsAg (anti-HBs) (HBsAg/Ab) was administered to BALB/c mice by intranasal inhalation. HBsAg by itself did not induce immune responses, whereas with HBsAg/Ab complexes, both systemic and mucosal immune responses were observed and these could be modulated by adjuvants. With HBsAg/Ab (1 or 10 microg), anti-HBs antibodies induced were predominantly of the IgG1 isotype (Th2-like). In contrast, anti-HBs induced by HBsAg/Ab plus cholera toxin (CT) or oligodeoxynucleotides (ODN) containing immunostimulatory CpG motifs (CpG) (1 microg each) were predominantly IgG2a (Th1-like). Results from this study indicate that HBsAg/Ab complexes can induce strong humoral immune responses when delivered by a noninvasive route, whether used alone or in combination with other mucosal adjuvants.

Effect of plasmid DNA on immunogenicity of HBsAg-anti-HBs complex

Hepatitis B surface antigen (HBsAg) complexed with anti-HBs is more immunogenic than HBsAg alone in mice. This complex is usually used with alum as an adjuvant, which can enhance humoral response but inhibits cell-mediated immune responses. To improve the immunogenicity of HBsAg-anti-HBs, we immunized mice with a combination of this immunogenic complex and pCMVHBs, a plasmid encoding HBsAg, or the vector pCMV. Both plasmids enhanced the anti-HBs response induced by the immunogenic complex. We found 20 microg of plasmid or vector enhanced the anti-HBs response in all mice, whereas 1 microg was less effective. Splenocytes from different immunized groups were stimulated with HBsAg in vitro, and the highest level of IL-2 detected in the supernatant was found in mice immunized with HBsAg-anti-HBs plus pCMVHBs. A plasmid (pcDNA3c191) encoding core protein of hepatitis C virus (HCV) was used as an adjuvant to the immunogenic complex. A preliminary result showed that pcDNA3c191 not only enhanced the immunogenicity of HBsAg-anti-HBs, but also induced anti-HCV core antibodies. Immunization using a plasmid DNA encoding one viral antigen in combination with antigen and antibody complex of another microbial origin could be a new approach to the development of multivalent vaccines.

Mutations in the 'a' determinant of hepatitis B surface antigen among Chinese infants receiving active postexposure hepatitis B immunization

Twenty-four infants who became positive to the surface antigen of hepatitis B virus (HBsAg) despite a complete course of active postexposure immunization with plasma derived hepatitis B vaccine were studied. The polymerase chain reaction amplified products of the common neutralizing epitope 'a' determinant of HBsAg (Nucleotide 419-598) from serum samples were sequenced and analyzed for nucleotide mutations. Four cases (16.7%) had mutations that led to amino acid substitutions between codons 124 and 147. Only one case (N1) showed a substitution at codon 145 (from glycine to arginine, 145R), the other three were at codons 126-129. The mother of N1 was co-infected with the wild type and the mutant virus. Five years later, serum of N1 showed only the wild type virus. There was no significant relationship between the mutation rate and the anti-HBs response to hepatitis B vaccination. Results suggest that without immune selective pressure, 145R variant was not frequently observed, and was not stable. Mutation in the 'a' determinant was not an important cause of failure to prevent maternal-infant transmission of HBV by active postexposure hepatitis B immunization in Chinese children.

Expression, purification, and partial characterization of HCV RNA polymerase

The product of the NS5B gene of Hepatitis C Virus (HCV) has been expressed in Escherichia Coli both as a fusion protein with glutathione-S-transferase (GST) of molecular weight 91 KDa and at high level as a single protein of molecular weight 65 KDa. The protein was sequestered within inclusion bodies and a variety of procedures designed to minimize inclusion body formation proved unsuccessful. The method finally adopted involved the purification of inclusion bodies followed by the solubilization, purification, and refolding of the expressed protein. A good recovery and protein purity of the order of 80-90% were achieved. The purified protein was shown to possess RNA polymerase activity in an assay using polyA/oligoU as template. The enzymatic activity is rifampicin resistant, poly A dependent, and requires Mg++. The availability of purified HCV RNA polymerase will allow the study of viral replication and constitute the basis for testing new anti-viral drugs.

Frequency of hepatitis B virus e-minus mutants varies among patients from different areas of China

Four hundred forty-six serum samples from HBsAg-positive chronic hepatitis B patients were collected from five areas in China (eastern coastal city, Shanghai; southwestern inland city, Chengdu; mid-inland city, Wuhan; southern island city, Haikou; and northeastern city, Changchun). Precore stop codon variants (e-minus mutants) were screened using a rapid method of polymerase chain reaction (PCR) amplification of a precore and partial core gene fragment (nucleotides 1785-2172), followed by dot-blot hybridization with specific oligonucleotide probes (M0, and M1 + M2). The sequence of the M0 probe covered the distal precore region of wild-type virus (nucleotides 1887-1908), and the sequences of the M1 and M2 probes were from sequences mutated at nt. 1898, (TGG-->TAG) with or without additional change at nt. 1901. A significantly lower incidence of the precore stop codon was found in anti-HBe-positive serum samples from Haikou (17.6%), whereas in other areas the percentages of this mutation in anti-HBe positive sera ranged from 47.4% to 78.9%. In HBeAg-positive samples, the rate of e-minus mutant in coexistence with wild-type virus was low in specimens from Haikou (9.5%) and Changchun (2.9%) compared to other areas in China. In contrast, coexistence of mutant and wild-type virus was frequently detected in samples from Wuhan (50.0%).

Recombinant vaccinia virus expressing Pre-S/S protein of duck hepatitis B virus and its preliminary use for treatment of persistent infection

The envelope (Pre-S/S) gene of duck hepatitis B virus (DHBV) was amplified by polymerase chain reaction (PCR) and cloned into plasmid pGJP5, under the control of vaccinia virus promoter P(7.5). By recombination in cell culture, and screened in human TK- 143 cells in the presence of 5-bromouracil deoxyriboside (5-BUdR), a recombinant vaccinia virus, bearing the envelope gene of DHBV (pGDHBV-5) which could replicate in cell cultures was constructed. DHBV surface antigen (DHBsAg) was detected in pGDHBV-5-infected cell lysate by dot enzyme immunoassay (EIA). After multiple-site intradermal injections of pGDHBV-5, DHBsAg could be detected in the serum of immunized adult ducks. This indicated that the recombinant virus replicated and expresed DHBsAg in ducks. The recombinant virus was used as a therapeutic vaccine to immunize persistently DHBV-infected ducks. After immunization, a transient significant decrease of serum DHBsAg was observed.

Anti-HBe titre in patients infected with wild-type and e-minus variant of hepatitis B virus

Serum samples from 77 HBsAg- and anti-HBe-positive chronic hepatitis B patients were studied for a G to A point mutation at the 1896 nucleotide of the precore region by polymerase chain reaction and oligonucleotide hybridization. Patients were grouped as: A, infected only by the wild-type virus; B, infected only by e-minus variant; C, coinfected by the wild-type and e-minus variant; and D, no precore/core gene of hepatitis B virus detected. All samples were assayed for the titre of anti-HBe by ELISA and compared as grouped. A significantly higher titre was found in the coinfected group C compared to groups A (p < 0.01) and D (p < 0.05). Results indicate that a high titre of anti-HBe is required as immune selective pressure for E-minus variant to overtake the wild-type virus.

Enhanced immunogenicity in mice with hepatitis B vaccine complexed to human hepatitis B immunoglobulin

Purified human hepatitis B immunoglobulin (HBIG) was complexed to plasma derived hepatitis B vaccine (HBVac) at different concentrations and used to immunize Balb/c mice. An enhanced humoral immune response was observed when HBVac was complexed to HBIG in excess of antigen, compared to that immunized with the vaccine alone. Proliferation of splenic lymphocytes was detected when mice were immunized with HBIG complexed to HBVac (0.2-1 microgram), whereas in mice immunized only with HBVac at one microgram, no lymphocyte proliferation was observed. The enhanced immunogenicity of HBIG: HBVac is T cell dependent. The importance of using critical ratio of HBIG and HBVac is indicated, and future application of this complex for vaccination of low- or nonresponders to the present HBVac, as well as for treatment of chronic hepatitis B patients is discussed.

Solid matrix-antibody-antigen complex can clear viraemia and antigenaemia in persistent duck hepatitis B virus infection

One-day-old ducklings experimentally infected with duck hepatitis B virus (DHBV) were found to be immunologically tolerant to virus antigens (DHBsAg, DHBcAg), with no humoral or cellular immune responses being detected. When immunized with virus antigens in Freund's complete adjuvant, no immune responses could be induced. Rabbit anti-DHBs sera were complexed to a solid matrix (Staphylococcus aureus Cowan A strain) and purified DHBsAg was bound to this complex to form a solid matrix antibody-antigen (SMAA) complex. This SMAA was used as an immunogen to immunize the tolerant ducks. After three injections, in 12 of 17 ducks serum DHBV DNA became absent and serum DHBsAg was cleared. In eight of 16 ducks, low titres of anti-DHBs could be detected. The SMAA approach shows potential for application in immunoregulatory treatment for chronically infected hepatitis B patients.

The sartorius myocutaneous island flap

The vascular supply to the distal part of sartorius m. was studied in 37 limbs by dissection under magnification and after black ink and latex injections. The muscle or myocutaneous island flap pedicled on the saphenous artery (SA) is supplied by a retrograde circulation through anastomoses of the SA with the perforating branches of the posterior tibial artery and the medial inferior genicular artery. Three different vascular patterns were defined. Retrograde injection also showed good perfusion of the SA. The flap is useful for covering around the knee, the proximal and middle thirds of the lower leg, and the end of the amputation stump. Raising of the flap has not resulted in any functional or cosmetic defect. Eighteen operations have so far been performed, six using the muscle island flap and twelve using the myocutaneous island flap, and all survived completely.

Hepatitis B virus genotype A rarely circulates as an HBe-minus mutant: possible contribution of a single nucleotide in the precore region

The emergence of HBe-minus hepatitis B virus (HBV) mutants, usually through a UAG nonsense mutation at codon 28 of the precore region, helps the virus to survive the anti-HBe immune response of the host. Host and viral factors that predispose to the emergence of such mutants are not well characterized. The fact that the precore region forms a hairpin structure essential for the packaging of viral pregenomic RNA may explain the extremely high prevalence of the UAG mutation at codon 28. It converts a wobble U-G pair in the packaging signal between nucleotide 3 of codon 15 (CCU) and nucleotide 2 of codon 28 (UGG) into a U-A pair. Since genotype A of HBV has a CCC sequence at codon 15, the UAG mutation would, instead, disrupt a C-G pair present in the wild-type virus. This alteration was shown by transfection experiments to greatly compromise the packaging of pregenomic RNA. The implication of this finding was elucidated by molecular epidemiological studies. Genotype A was found to be the most prevalent genotype in the wild-type virus populations in France but was found in only 1 of the 46 isolates of HBe-minus mutants found there. These mutants were contributed chiefly by genotype D, the second most prevalent genotype in France, which is characterized by a CCU sequence at codon 15. The role of the single nucleotide at codon 15 was confirmed by the finding of the single genotype A isolate in which both wild-type and mutant viruses were present. Interestingly, nearly all of the mutants had a codon 15 sequence of CCU instead of the CCC present in the wild-type viruses. Our results suggest that genotype A of HBV rarely circulates as HBe-minus mutants, probably because of a requirement for a simultaneous sequence change at codon 15. These data, together with the virtual absence of genotype A in the Chinese samples examined, may provide some insights into the uneven prevalence of HBe-minus mutants in the world.

[Study on cisplatin albumin microspheres for neck external artery embolization]

In this paper the technique of emulsion chemical-crosslinking was used to prepare cisplatin albumin microsphere for jaw squamous cancer by neck external artery embolization. It was yellow powder with yield 80 +/- 5%, mean size 56.3 microns, cisplatin concentration 14.02-14.20%, loading rate 97.08-97.95%. The release characteristics in vitro, sterilization, stability and recipe of disperse solvent of cisplatin albumin microsphere were investigated. Animal test showed that cisplatin albumin microsphere may plug the branches of neck external artery well and remain in local tissue.

Elimination of immune tolerance to hepatitis virus in an animal model

Four-day old ducklings were infected with duck hepatitis B virus to simulate perinatal transmission of hepatitis B virus. Immune tolerance was characterized as persistent viremia, antigenemia, without detection of anti-DHBs or anti-DHBc. A synthetic peptide, P125-146, mimicking one of the epitopes of the native DHBV Pre-S protein was used to cross-link to tetanus toxoid or phytohemagglutinin. These 'novel' antigens were used to immunize immune tolerant ducks, aimed at bypassing T cell tolerance. After 5 injections, though no anti-DHBV Pre-S was detected, around 50% of the immunized ducks showed seroconversion to DHBV DNA negative.

Location of myocardial infarction and its surface cardioelectric representation. An experimental study

In order to explore the relationship between the different location of myocardial infarction (MI) and reflections of pathognomonic Q potentials on the body surface, an experimental study was carried out in 28 dogs. The results were (1) in 27 of a total 28 dogs after MI formation, abnormal Q maps appeared; (2) right ventricular MI, posterior wall MI and some lateral and apical MI are prone to miss abnormal Q potentials in the conventional 12-lead ECG; and (3) the MI location and relative size diagnosed through electrocardiographic peak mapping (EPM) correlated to acute MI in dog ventricles fairly well. The unexpected Q map reflections of right ventricular MI provide new clues for improving our automatic diagnosis system after further correlative studies. The results strongly support the feasibility of the application of EPM in clinical diagnosis.

A synthetic peptide elicits antibody reactive with the native duck hepatitis B virus pre-S protein

Synthetic peptides P37-49 and P63-79, derived from the pre-S region of duck hepatitis B virus (DHBV), have been synthesized. Only P37-49 was reactive with rabbit anti-DHBs/pre-S antibodies by radioimmunoprecipitation. Antiserum prepared against P37-47 reacted with a 35K polypeptide of native DHBs/pre-S by immunoblotting. It is concluded that P37-49 (MGQHPAKSMDVRR) mimics one of the epitopes of the DHBV pre-S antigen.

The affinity of anti-HBc antibodies in acute and chronic hepatitis B infection

Antibodies to hepatitis B core antigen (anti-HBc) are found in the sera of all individuals infected with hepatitis B virus. A role for these antibodies has been suggested in determining the outcome of infection. In this study, the affinity of anti-HBc antibodies in asymptomatic virus carriers was compared with that of antibodies present in the sera of patients with chronic liver disease. Persistently infected individuals with no evidence of clinical disease were found to have anti-HBc antibodies of greater affinity, compared with the chronic liver disease group. Sera from patients with chronic hepatitis contained high levels of low-affinity antibody whereas antibody levels in asymptomatic carriers were significantly lower. These findings are discussed in relation to the predicted role of anti-HBc antibodies in mediating hepatitis B virus-related hepatocellular injury.

[Studies on the hepatitis B virus in cell culture: I. Expression of cloned HBV DNA in the HEP G2 cell line]

To study the interactions between HBV and host cells, cloned adr subtype HBV DNA dimer was used to transfect Hep G2 cell line. Five days after transfection, HBeAg could be detected in the supernatant and reached its peak on the 11th day. It was still positive on the 25th day. In contrast, HBsAg was only positive on the 8th day, and gradually increased until the 25th day when the amount of HBsAg was still rising. Supernatant of HBeAg positive samples was collected and after ultracentrifugation, was checked by electron microscopy. HBV like particles of 42 nm in diameter were detected. The prospect of employing this transient cell expression system for studies of HBV replication, inhibitory effects of drugs and immunological factors are discussed.

ECG left anterior fascicular block reveals diverse patterns on scintigraphic phase analysis

Left anterior fascicular block (LAFB) remains an uncertain diagnosis by scalar ECG, particularly with coexisting inferior infarction. To assess the use of phase analysis in LAFB, left ventricular phase and amplitude maps were evaluated in the 70-degree left anterior oblique projection in eight control patients and 13 patients with LAFB who met the ECG criteria of Warner et al. The left ventricular region was divided into anterior (A) and inferior (I) segments. Contraction patterns were assessed by examination of the sequence of phase angles (phi), relative contraction time of the anterior versus inferior segments was assessed from the difference between segment mean phase angles, delta phi A-I, determined from the phase histogram, and duration of contraction was assessed by histogram width. Relative stroke volume was assessed on the amplitude image. Eight control subjects had normal amplitude, contraction of the anterior before inferior segment, narrow histogram width, and a normal ECG. Among the 13 patients with ECG LAFB, seven were concordant, with phase analysis demonstrating anterior contraction delay. Two of seven patients had narrow histograms and normal amplitude, which were compatible with isolated anterior conduction delay, and five of seven patients had broad histograms and reduced anterior amplitude, compatible with anterior infarction. Phase analysis was discordant with ECG LAFB diagnosis in six patients. All showed contraction of anterior segments before inferior segments as in normal subjects. Four had broad histograms and reduced inferior amplitude, compatible with prior inferior infarction without LAFB, and two had normal phase and amplitude maps. Phase patterns appear characteristic of LAFB with or without associated infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum interferon in systemic lupus erythematosus

Serum interferon levels were estimated in 67 samples obtained from 47 patients with SLE. Levels were increased in 70% of the samples and 72% of the patients. In the patients with active disease 81% had increased interferon levels, while in the group with clinically quiescent disease 10% had increased levels. In 20 patients retested 3 1/2 months after treatment the changes in interferon levels tended to parallel the changes in clinical disease activity in 80% of cases. Patients with active skin lesions, arthritis, and renal or haematopoietic involvement tended especially to have increased interferon levels. Interferon levels were directly related to ANA titre and inversely related to serum C3 levels, but not related to serum levels of circulating immune complexes or immunoglobulin. The interferon was shown to be of type alpha. The interferon level can be regarded as one of several parameters reflecting disease activity and may also be related to the prognosis. As it is possible that interferon may be a direct mediator of the pathophysiology of auto-immune disease, we do not recommend the use of interferon or its inducers in the therapy of SLE.

Mechanism of interferon action III--significance of pppA2'p5'A2'p5'A in the antiviral action of interferon

This paper is to evidence that the antiviral effect of pppA2'P5'A2'P5'A(2'-5'P3A3) could cover a wide spectrum of viruses, the RNA viruses such as influenza H3N2/77, influenza H1N1/77, ECHO11, rhino, Sendai, Sindbis and VSV, and the DNA viruses such as herpes (type I). In addition, the antiviral effect of 2'-5'P3A3 on ECHO11 virus, as compared with other viruses, is more efficient than that of IFN. It seems likely that 2'-5'P3A3 plays an important role in the antiviral action of IFN. After comparing the action of 2'-5'P3A3 with interferon (IFN), it has appeared that the action of 2'-5'P3A3 is something parallel to that of IFN for most viruses. For a few viruses, however, considerable differences have been observed.

Nuclear antigen detected in hepatoma cell lines containing integrated hepatitis B virus DNA

We identified, by anticomplement immunofluorescence, a nuclear antigen (hepatitis B virus-associated nuclear antigen [HBNA]) in two human hepatoma cell lines containing integrated hepatitis B virus DNA but not in three hepatoma cell lines lacking it. The antigen resembled neoantigens associated with the oncogenesis of certain papovaviruses, adenoviruses, and herpesviruses. Antibody to the antigen (anti-HBNA) was found in 7.3% of hepatitis B surface antigen-positive sera from patients with hepatocellular carcinoma but not in surface antigen-negative sera. The staining of HBNA was characterized by two patterns, reticular nuclear fluorescence and nucleolar fluorescence. The expression of HBNA did not parallel the production of extracellular hepatitis B surface antigen. Treatment of cells with proteinase K, RNase, DNase, or cycloheximide significantly diminished the staining of HBNA.