Hepatitis C virus quantification in serum and saliva of HCV-infected patients

The hepatitis C virus (HCV) can be detected in blood and other bodily fluids, such as saliva, semen and gastric juices. The aim of this study was to compare the HCV viral loads in the serum and saliva of infected patients. Twenty-nine patients with detectable HCV RNA in their serum and saliva were included in this study. The HCV viral loads were determined through quantitative real-time polymerase chain reactions. The median viral RNA levels were 5.78 log10 copies in the serum and 3.32 log10 copies in the saliva. We observed that the salivary HCV viral load was significantly lower than the viral load in the serum. Further studies are required to understand the role of saliva in the diagnosis, management and potential transmission of HCV.     

Inhibition of viral DNA synthesis in stationary chicken embryo fibroblasts infected with avian retroviruses.

Previously, we reported (Fritsch and Temin, J. Virol. 21:119-130, 1977) that infectious viral DNA was not present in spleen necrosis virus-infected stationary chicken cells. However, a stable intermediate was present in such infected stationary cells as evidenced by the appearance of infectious viral DNA shortly after serum stimulation of these cells. After serum stimulation of infected stationary cells, the infectious viral DNA appeared first in the nucleus. In contrast, in infected dividing cells the infectious viral DNA appeared first in the cytoplasm. Significantly reduced amounts of complete plus- or minus-strand viral DNAs were detected by nucleic acid hybridization in stationary chicken cells infected with spleen necrosis virus or Schmidt-Ruppin Rous sarcoma virus compared with the amounts detected in infected dividing cells. These experiments indicated that infected stationary cells did not contain complete noninfectious copies of viral DNA. Furthermore, 5-bromodeoxyuridine labeling and cesium chloride density gradient centrifugation analysis of the infectious viral DNA that appeared after serum stimulation of infected stationary cells indicated that most viral DNA synthesis occurred after addition of fresh serum.     

Possibilities of vaccine manufacture in human diploid cell strains with a serum replacement factor.

Cell lines MDCK (canine kidney), BGM (Buffalo green monkey kidney) and human embryonic lung fibroblast will support viral growth efficiently in medium without serum. Both MRC-5 and WI-38 cell strains have been approved by the Food and Drug Administration for manufacturing viral vaccines against cytomegalovirus and varicella-zoster virus. In this study we examine these two cell lines and viruses for their ability to grow in medium containing a serum replacement. The serum substitute used is LPSR-1 (low protein serum replacement). Using LPSR-1 in defined medium, we demonstrate multipassage cell growth and viral cultivation and replication equivalent to those obtained in medium containing fetal bovine serum (FBS). Viral growth after complete elimination of FBS varies and depends on cell line and virus. Serum substitutes can eliminate FBS in the viral growth phase of vaccine production and reduce costs.     

Viral RNA kinetics is associated with changes in trace elements in target organs of Coxsackie virus B3 infection

Trace elements are pivotal for the host defense, as well as potentially important for viral replication and virulence. Studies of sequential changes in viral replication in target organs of infection are sparse and a possible association with changes in specific trace elements is unknown. In this study Balb/c mice were infected with Coxsackie virus B3 (CVB3). Results indicated that sequential changes in viral replication (RT-PCR) were related to changes in trace element (arsenic, copper, iron, selenium and zinc) concentrations (as determined by ICP-MS) on days 3, 5 and 7 of the infection in serum, heart, lung, liver, pancreas, kidney, spleen, intestine and brain. After an initial viral peak on day 3, viral load drastically decreased in all organs, i.e. by >99% (serum), 97% (lung), 98% (liver), 60% (pancreas), 95% (kidney) and 93% (spleen), except in the heart, intestine and brain in which viral load increased after day 3. Selenium decreased in all organs except the heart while arsenic decreased in all organs except the kidney, spleen and brain. Moreover, selenium was negatively correlated to viral load in serum, liver, pancreas and intestine. To conclude, these findings give evidence that trace elements are directly involved in the replication of CVB3.     

Comparative information value of humoral immunity characteristics in some bacterial and viral infections

Serological examination of 144 patients with different bacterial and viral infections was carried out. Antibodies to Brucella were detected in blood serum in 42 patients (85.7%) with the average titer of 1:996 and in saliva in 41 patients (83.7%) with the average titer of 1:567 by passive hemagglutination test with brucella erythrocyte diagnosticum. Out of 26 dysentery patients, antibodies in blood serum were detected in the diagnostic titer in 17 patients (65.4%) with the average titer of 1:282 and in saliva in 21 patients (80.8%) in the titer of 1:100 and higher. Anti-HAV and anti-HBc IgM were detected in specimens of saliva from patients with serologically confirmed viral hepatitis A and B in 100% of cases. The presence of HBsAg in saliva from hepatitis B patients was established in 95.4% of cases. In blood serum and in specimens of saliva anti-HCV IgM were detected in 100% and 85.7% of cases respectively. Out of 25 women with aggravated obstetric history, IgG antibodies to CMV were detected in blood serum in 23 women (88.5%) and in saliva in 22 women (84.6%). The results of these investigations revealed that the detection rate of antibodies in blood serum and saliva in cases of infections, both bacterial (brucellosis, shigellosis) and viral (hepatitis A, B, C and CMV infection), was not essentially different. The simplicity of obtaining material for analysis make it possible to recommend the use of saliva for diagnosing bacterial and viral infections, especially in mass epidemiological surveys.     

Conditions necessary for inhibition of protein synthesis and production of cytopathic effect in Aedes albopictus cells infected with vesicular stomatitis virus.

The relationship between the development of cytopathic effect (CPE) and the inhibition of host macromolecular synthesis was examined in a CPE-susceptible cloned line of Aedes albopictus cells after infection with vesicular stomatitis virus. To induce rapid and maximal CPE, two conditions were required: (i) presence of serum in the medium and (ii) incubation at 34 degrees C rather than at 28 degrees C. In the absence of serum, incubation of infected cultures at 34 degrees C resulted in a significant increase in viral protein and RNA synthesis compared with that observed at 28 degrees C. However, when serum was present in the medium, by 6 h after infection protein synthesis (both host and viral) was markedly inhibited when infected cells were maintained at 34 degrees C. RNA synthesis (host and viral) was also inhibited in vesicular stomatitis virus-infected cells maintained at 34 degrees C with serum, but somewhat more slowly than protein synthesis. Examination of polysome patterns indicated that when infected cultures were maintained under conditions which predispose to CPE, more than half of the ribosomes existed as monosomes, suggesting that protein synthesis was being inhibited at the level of initiation. In addition, the phosphorylation of one (or two) polysome-associated proteins was reduced when protein synthesis was inhibited. Our findings indicate a strong correlation between virus-induced CPE in the LT-C7 clone of A. albopictus cells and the inhibition of protein synthesis. Although the mechanism of the serum effect is not understood, incubation at 34 degrees C probably predisposes to CPE and inhibition of protein synthesis by increasing the amount of viral gene products made.     

Analysis of Hepatitis C Virus Decline during Treatment with the Protease Inhibitor Danoprevir Using a Multiscale Model

The current paradigm for studying hepatitis C virus (HCV) dynamics in patients utilizes a standard viral dynamic model that keeps track of uninfected (target) cells, infected cells, and virus. The model does not account for the dynamics of intracellular viral replication, which is the major target of direct-acting antiviral agents (DAAs). Here we describe and study a recently developed multiscale age-structured model that explicitly considers the potential effects of DAAs on intracellular viral RNA production, degradation, and secretion as virus into the circulation. We show that when therapy significantly blocks both intracellular viral RNA production and virus secretion, the serum viral load decline has three phases, with slopes reflecting the rate of serum viral clearance, the rate of loss of intracellular viral RNA, and the rate of loss of intracellular replication templates and infected cells, respectively. We also derive analytical approximations of the multiscale model and use one of them to analyze data from patients treated for 14 days with the HCV protease inhibitor danoprevir. Analysis suggests that danoprevir significantly blocks intracellular viral production (with mean effectiveness 99.2%), enhances intracellular viral RNA degradation about 5-fold, and moderately inhibits viral secretion (with mean effectiveness 56%). The multiscale model can be used to study viral dynamics in patients treated with other DAAs and explore their mechanisms of action in treatment of hepatitis C.     

光敏生物素标记cDNA探针在肾综合征出血热实验诊断中的初步应用

本文用光敏生物素标记的R3 cDNA探针杂交检测了HFRS患者外周血淋巴细胞、血清和尿沉淀细胞中HFRS病毒核酸。结果42份淋巴细胞标本中30份为阳性,48份血清标本中有24份出现阳性杂交信号,81份尿沉淀细胞标本中53份为阳性,表明将此光敏生物素标记的cDNA探针用于HFRS实验诊断和致病机理的研究是可行的。     

Experience in the detection of the latent course of the epidemic process of viral hepatitis in children in preschool groups]

A complex study of 1273 healthy children of creches and kindergartens where no viral hepatitis occurred for a long time revealed 39 children (3.1%) with an increased activity of glutamine-pyroracemic transaminase in the blood serum. Viral hepatitis was diagnosed in 12 (0.94%) of them as a result of clinical examination (an icteric form in 1, and a nonicteric form in 11 cases). The presence of asymptomatic form of infection could be supposed in 17 other children (1.3%). The incidence of increased activity of the enzyme in the serum of "healthy" children was definitly connected with the viral hepatitis incidence registered in the town during the year as a whole, and by seasons. This permitted to prognosticate the spread of viral hepatitis in the given populated locality. By complex laboratory examination of children in collective bodies it was possible to detect the latene foci and the latently coursing epidemic process of viral hepatitis.     

Advantage of PCR for detecting low amounts of HBV DNA in patients' sera

Serum hepatitis B virus DNA (HBV DNA) is now the most important and reliable marker for monitoring viral replication. Quantitative detection of HBV DNA in serum is based on a commercial standardized solution hybridization assay (Genostics). In this work, we studied the sensitivity and specificity of this method, in comparison with the polymerase chain reaction (PCR) technique, for low-value HBV DNA serum samples. Fifty-four patients with or without HBV serological markers were divided into 4 groups according to their HBV DNA values.Genomic amplication was found to affect 2 conserved regions of the viral genome, the S and C regions. Samples with an HBV DNA concentration equal to or greater than 1.5 pg/ml were considered positive in the “Genostics” test. A total of 38% of patients considered negative in the quantitative assay (< 1.5 pg/ml) were found to be positive for HBV DNA in serum after PCR. Only 26% of patients with an HBV DNA concentration of between 1.5 and 10 pg/ml in the Genostics test had PCR-detectable viral DNA in serum. Some 56% of patients with HBV DNA values between 10 and 20 pg/ml were found to be positive after amplification. All patients whose HBV DNA values were above 20 pg/ml had PCR-detectable viral DNA in serum.Our PCR results suggest that the positive limit level of the Genostics test has to be re-evaluated. Indeed, for low values of HBV DNA (under 20 pg/ml and especially under 10 pg/ml), it is not possible to conclude about the positivity from the quantitative assay, and results have to be estimated according to the clinical and serological status of the patients. Moreover, PCR can be falsely negative because of methodological problems.Nevertheless, this study confirms that PCR does enable detection of the viral genome in HBV-seronegative patients and in “old” and “cured” HBV-infection marker carriers.     

中枢神经系统感染患儿血清和脑脊液CRP、PCT、TNF-α及MMP-9水平及其临床意义

目的:探讨中枢神经系统感染患儿血清和脑脊液C反应蛋白(CRP)、降钙素原(PCT)、肿瘤坏死因子-α(TNF-α)及基质金属蛋白酶-9(MMP-9)水平及其临床意义。方法:选择2017年1月~2018年6月期间南京市第二医院收治的中枢神经系统感染患儿93例作为研究对象,其中化脓性脑膜炎62例记为化脓性脑膜炎组,病毒性脑炎31例记为病毒性脑炎组,另选取同期于我院治疗的非中枢神经系统感染患儿40例作为对照组,比较各组血清、脑脊液CRP、PCT、TNF-α、MMP-9水平及阳性率,并计算血清和脑脊液CRP、PCT、TNF-α、MMP-9诊断中枢神经系统感染的灵敏度、特异度及准确度。结果:化脓性脑膜炎组患儿血清、脑脊液CRP、PCT、TNF-α及MMP-9水平及阳性率高于病毒性脑炎组和对照组,病毒性脑炎组患儿血清、脑脊液CRP、TNF-α及MMP-9水平及阳性率高于对照组(P<0.05),病毒性脑炎组与对照组血清、脑脊液PCT水平及阳性率比较无统计学差异(P>0.05)。血清或脑脊液CRP+PCT+TNF-α+MMP-9联合检验对中枢神经系统感染具有一定的诊断价值。结论:中枢神经系统感染患儿血清、脑脊液CRP、TNF-α、PCT及MMP-9水平明显升高,其中化脓性脑膜炎患儿血清、脑脊液PCT水平高于病毒性脑炎患儿,血清或脑脊液CRP、PCT、TNF-α及MMP-9联合检验对儿童中枢神经系统感染的鉴别诊断具有较高的价值。     

Retroviral vector production under serum deprivation: The role of lipids

The use of retroviral vectors for gene therapy applications demands high titer preparations and stringent quality standards. However, the manufacturing of these vectors still represents a highly challenging task due to the low productivity of the cell lines and reduced stability of the vector infectivity, particularly under serum‐free conditions. With the objective of understanding the major limitations of retroviral vector production under serum deprivation, a thorough study of viral production kinetics, vector characterization and cell growth and metabolic behavior was conducted, for 293 FLEX 18 and Te Fly Ga 18 producer cell lines using different serum concentrations. The reduction of serum supplementation in the culture medium resulted in pronounced decreases in cell productivity of infectious vector, up to ninefold in 293 FLEX 18 cells and sevenfold in Te Fly Ga 18 cells. Total particles productivity was maintained, as assessed by measuring viral RNA; therefore, the decrease in infectious vector production could be attributed to higher defective particles output. The absence of the serum lipid fraction was found to be the major cause for this decrease in cell viral productivity. The use of delipidated serum confirmed the requirement of serum lipids, particularly cholesterol, as its supplementation not only allowed the total recovery of viral titers as well as additional production increments in both cell lines when comparing with the standard 10% (v/v) FBS supplementation. This work identified lower production ratios of infectious particles/total particles as the main restraint of retroviral vector production under serum deprivation; this is of the utmost importance concerning the clinical efficacy of the viral preparations. Lipids were confirmed as the key serum component correlated with the production of infective retroviral vectors and this knowledge can be used to efficiently design medium supplementation strategies for serum‐free production. Biotechnol. Bioeng. 2009; 104: 1171–1181. © 2009 Wiley Periodicals, Inc.     

Cellular functions are required for the synthesis and integration of avian sarcoma virus-specific DNA.

We have used two experimental strategies to test the role of cellular functions in the synthesis and integration of virus-specific DNA in cells infected by avian sarcoma virus.First, quail embryo fibroblasts, placed in stationary phase (G₀) by prolonged serum starvation, did not support the efficient synthesis of viral DNA during the first 24–48 hr after infection. Synthesis of viral DNA was impaired according to at least two parameters: the amount of DNA was diminished, particularly the amount of the plus-strand DNA (identical in polarity to the viral genome); and the length of both minus and plus strands was reduced in the stationary cells. In parallel cultures fed with fresh serum, over two thirds of the cells were able to reenter the cell cycle within 24 hr, and viral DNA of normal size was synthesized.Second, density labeling of viral and cellular DNA with BUdR was used to determine whether cellular DNA synthesis was required for integration of viral DNA. In both quail embryo fibroblasts released from G₀ by serum replacement and randomly growing duck embryo fibroblasts, viral DNA was integrated only into cellular DNA replicated during the infection.Our results indicate that serum-starved cells lack a factor (or factors) required for the efficient and complete synthesis of ASV-specific DNA. We have not been able to establish whether such factor(s) are present in growing cells only during S phase. Integration of viral DNA appears to require cellular DNA synthesis; this may be due to a requirement for a factor (or factors) present in adequate concentration only during S phase or to a requirement for the structural changes in cellular DNA that accompany replication.     

Autogenous Immunity to Endogenous RNA Tumor Virus: Differential Reactivities of Immunoglobulins M and G to Virus Envelope Antigens

The autogenous humoral immune response of mice to their endogenous leukemia virus has been examined in terms of the reactivities of individual classes of antibody present in normal B6C3F(1) serum. Whole serum and the immunoglobulin (Ig) M and IgG fractions of serum from animals of different age groups were compared by radioimmune precipitation assays and viral infectivity neutralization assays. Both IgM and IgG fractions were able to precipitate virus, although not as effectively as whole serum. Virus-specific antibody levels, as well as total antibody concentrations in whole serum, appeared to increase with age. Sodium dodecyl sulfate gel electrophoresis analysis was performed with immune precipitates obtained when whole serum or 19 or 7S fractions from animals of different age groups were reacted with disrupted virus. The 19S antibody fraction reacted with three antigenic determinants on the viral envelope. These antigens have apparent molecular weights of 17,000, 43,000, and 68,000. The last two appear to be glycoproteins and may correspond to the M(2) and M(1) antigens. In contrast, the 7S component reacted only with the 17,000-molecular-weight protein. Neutralization assays against BALB:virus-2, a xenotropic endogenous mouse type C virus, revealed that 19S and whole serum but not the 7S fraction possessed neutralizing activity. These findings indicate that there are differential reactivities of IgM and IgG antibodies in normal serum of B6C3F(1) mice, with respect to both recognition of viral envelope antigens and neutralization of endogenous MuLV. These results are consistent with the hypothesis that the autogenous humoral immune response is a systemic host function that may be important in the regulation of endogenous type C virus expression in vivo.     

Neutralization of vesicular stomatitis virus (VSV) by human complement requires a natural IgM antibody present in human serum

Neutralization of VSV by human serum ws previously shown to involve C1, C2, C3, and C4 of the classical complement (C) pathway. All normal human sera tested were equivalently active in this regard. However, purified C1, C2, C3, and C4 were unable to mediate VSV neutralization. In the present studies an additional factor required for C-mediated neutralization was isolated from normal human serum and identified as a natural IgM antibody specific for a viral encoded antigen. Purified IgM bound to the virus and formed a complex that activated component C1. Normal serum concentrations of purified IgM, C1, C2, C3, C4 neutralized VSV to the same extent as normal serum. Purified IgM did not neutralize VSV alone or in conjunction with C1, C2, and C4. Inclusion of C3 resulted in full neutralization and C3b binding to the virus was demonstrated. Thus, normal human serum contains a natural antibody of the IgM class that is directed toward a viral antigen. The antibody facilitates neutralization by forming an immune complex that activates C1 and thus efficiently initiates the classical pathway at the viral surface. Neutralization occurs with C3b deposition on the viral envelope and probably results from a blanket of C protein that interferes with viral attachment to susceptible cells.     

Correlation between serum enzymes and serum unsaturated vitamin B12 binding proteins in primary liver carcinoma

The serum unsaturated vitamin B12-binding capacity (UBBC), unsaturated transcobalamin (UTC) I, UTC II, UTC III levels, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities and bilirubin concentration were estimated in 61 patients with liver diseases (31 with hepatoma, 30 with viral hepatitis). The levels of serum cobalamin, UTC I, UTC III, UBBC, alanine and aspartate aminotransferases, and bilirubin were raised in both hepatoma and viral hepatitis patients. Serum UTC II was reduced in both conditions. Alkaline phosphatase activity was significantly increased in hepatoma. Four significant correlations were observed among these parameters in the hepatoma patients while only one significant correlation was observed in viral hepatitis.     

脑脊液乳酸和血清降钙素原及C反应蛋白 对小儿细菌性脑膜炎的诊断价值

目的探讨脑脊液乳酸、血清降钙素原及C反应蛋白对小儿细菌性脑膜炎的诊断价值。方法选取我院2016年4月至2017年6月收治的50例细菌性脑膜炎患儿以及50例病毒性脑膜炎患儿进行作为研究对象,比较2类患儿脑脊液乳酸(LA)、血清降钙素原(PCT)及C反应蛋白(CRP)的水平,并分析其诊断价值。结果细菌性脑膜炎组患儿脑脊液LA、血清PCT及CRP水平显著高于病毒性脑膜炎患儿(均P0.05)。血清PCT诊断的灵敏度和特异度最高(96.4%、90.9%,P0.05)。3项指标联合检测的灵敏度(100.0%)和特异度(95.5%)明显高于任一单项指标(均P0.05)。经过Pearson相关性分析,脑脊液LA、血清PCT及CRP与小儿细菌性脑膜炎均呈显著正相关关系(均P0.05)。结论脑脊液乳酸、血清PCT及CRP对小儿细菌性脑膜炎的诊断和治疗效果监测有重要应用价值。     

Therapeutic efficacy of Hypericum perforatum L. extract for mice infected with an influenza A virus

Hypericum perforatum L., a plant used in Chinese herbal medicine, has been proven effective against many viral diseases. In the present study, the therapeutic efficacy of an extract of H.?perforatum (HPE) against influenza A virus (IAV) was investigated in mice. Whether HPE would be a promising agent for influenza treatment was evaluated by measuring the protection rate, mean survival days, lung index, and viral titer, as well as the secretion of IL-6, interleukin-10 (IL-10), tumour necrosis factor-α (TNF-α), and interferon-gamma (IFN-γ) in lung tissue and serum on days 3 and 5 post-infection. The results showed that HPE could reduce the lung index and viral titer of mice infected with IAV, decrease mortality, and prolong the mean survival time. HPE decreased the concentration of IL-6 and TNF-α in lung tissue and serum on day 5 post-infection. In contrast, HPE enhanced the lung and serum levels of IL-10 and IFN-γ on the days 3 and 5 post-infection. Our study indicates that HPE has significant therapeutic efficacy for mice infected with IAV. The possible reasons for these results were concluded to be pertaining to up-regulating the expression of IL-10 and IFN-γ, and down-regulating the secretion of IL-6 and TNF-α in lung and serum.