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Infection Alone (infection + alone)
Selected AbstractsMaternal-infant transmission of hepatitis C virus infectionHEPATOLOGY, Issue 5B 2002Eve A. Roberts 555 University Ave. Mother-to-infant transmission of hepatitis C virus (HCV) is comparatively uncommon. The prevalence of antibody to HCV (anti-HCV) in pregnant women is 0.1% to 2.4%, although in some endemic areas it is much higher. The proportion of women with anti-HCV who have active infection with viremia is 60% to 70%. Transmission of HCV occurs only when serum HCV RNA is detectable and may be related to higher levels (above 106 copies per mL). The rate of mother-to-infant transmission is 4% to 7% per pregnancy in women with HCV viremia. Co-infection with human immunodeficiency virus (HIV) increases the rate of transmission 4 to 5 fold. The actual time and mode of transmission are not known. Elective Cesarean section is not recommended for women with chronic HCV infection alone. The role of treatment to prevent transmission is limited by the fetal toxicity of currently available medications for hepatitis C. Breast feeding poses no important risk of HCV transmission if nipples are not traumatized and maternal hepatitis C is quiescent. Pregnant women at high risk for HCV infection should be screened for anti-HCV, and HCV RNA testing should be performed if anti-HCV is positive. Infants of women with hepatitis C should be tested for HCV RNA on two occasions, between the ages of 2 and 6 months and again at 18 to 24 months, along with serum anti-HCV. The natural history of mother-to-infant hepatitis C remains uncertain, especially the course in the first year of life when some infants appear to have spontaneous resolution. [source] Maternal-infant transmission of hepatitis C virus infectionHEPATOLOGY, Issue S1 2002Eve A. Roberts M.D., FRCPC Mother-to-infant transmission of hepatitis C virus (HCV) is comparatively uncommon. The prevalence of antibody to HCV (anti-HCV) in pregnant women is 0.1% to 2.4%, although in some endemic areas it is much higher. The proportion of women with anti-HCV who have active infection with viremia is 60% to 70%. Transmission of HCV occurs only when serum HCV RNA is detectable and may be related to higher levels (above 106 copies per mL). The rate of mother-to-infant transmission is 4% to 7% per pregnancy in women with HCV viremia. Co-infection with human immunodeficiency virus (HIV) increases the rate of transmission 4 to 5 fold. The actual time and mode of transmission are not known. Elective Cesarean section is not recommended for women with chronic HCV infection alone. The role of treatment to prevent transmission is limited by the fetal toxicity of currently available medications for hepatitis C. Breast feeding poses no important risk of HCV transmission if nipples are not traumatized and maternal hepatitis C is quiescent. Pregnant women at high risk for HCV infection should be screened for anti-HCV, and HCV RNA testing should be performed if anti-HCV is positive. Infants of women with hepatitis C should be tested for HCV RNA on two occasions, between the ages of 2 and 6 months and again at 18 to 24 months, along with serum anti-HCV. The natural history of mother-to-infant hepatitis C remains uncertain, especially the course in the first year of life when some infants appear to have spontaneous resolution. (HEPATOLOGY 2002;36:S106,S113). [source] Virus infection and grazing exert counteracting influences on survivorship of native bunchgrass seedlings competing with invasive exoticsJOURNAL OF ECOLOGY, Issue 2 2006C. M. MALMSTROM Summary 1,Invasive annual grasses introduced by European settlers have largely displaced native grassland vegetation in California and now form dense stands that constrain the establishment of native perennial bunchgrass seedlings. Bunchgrass seedlings face additional pressures from both livestock grazing and barley and cereal yellow dwarf viruses (B/CYDVs), which infect both young and established grasses throughout the state. 2,Previous work suggested that B/CYDVs could mediate apparent competition between invasive exotic grasses and native bunchgrasses in California. 3,To investigate the potential significance of virus-mediated mortality for early survivorship of bunchgrass seedlings, we compared the separate and combined effects of virus infection, competition and simulated grazing in a field experiment. We infected two species of young bunchgrasses that show different sensitivity to B/CYDV infection, subjected them to competition with three different densities of exotic annuals crossed with two clipping treatments, and monitored their growth and first-year survivorship. 4,Although virus infection alone did not reduce first-year survivorship, it halved the survivorship of bunchgrasses competing with exotics. Within an environment in which competition strongly reduces seedling survivorship (as in natural grasslands), virus infection therefore has the power to cause additional seedling mortality and alter patterns of establishment. 5,Surprisingly, clipping did not reduce bunchgrass survivorship further, but rather doubled it and disproportionately increased survivorship of infected bunchgrasses. 6,Together with previous work, these findings show that B/CYDVs can be potentially powerful elements influencing species interactions in natural grasslands. 7,More generally, our findings demonstrate the potential significance of multitrophic interactions in virus ecology. Although sometimes treated collectively as plant ,predators', viruses and herbivores may exert influences that are distinctly different, even counteracting. [source] A comparison of epidemiologic and immunologic features of bronchiolitis caused by influenza virus and respiratory syncytial virusJOURNAL OF MEDICAL VIROLOGY, Issue 2 2005Roberto P. Garofalo Abstract We studied epidemiologic and immunologic factors in infants with bronchiolitis caused by influenza virus. The proportion of these infants who were male and who had an immediate family member with a history of asthma was similar to that of a control group of infants with respiratory syncytial virus (RSV) bronchiolitis. In subjects with influenza virus infection, concentrations of the beta chemokine macrophage inflammatory protein-1alpha (MIP-1,), but not other beta chemokines, in nasopharyngeal secretions (NPS) were greater among infants with more severe, hypoxic bronchiolitis than in subjects with mild, nonhypoxic bronchiolitis, or upper respiratory tract infection alone. Quantities of MIP-1, were also correlated with lower values of oxygen saturation. These findings point out epidemiologic and immunologic similarities between bronchiolitis caused by influenza and RSV, and suggest that host factors are more important than the nature of the infecting virus in the development of severe forms of bronchiolitis caused by influenza and RSV. J. Med. Virol. 75:282,289, 2005. © 2004 Wiley-Liss, Inc. [source] Interaction between hepatitis B and C viruses in hepatocellular carcinogenesisJOURNAL OF VIRAL HEPATITIS, Issue 3 2006M. C. Kew Summary., Although hepatitis B (HBV) and C viruses (HCV) are, individually, major causes of hepatocellular carcinoma, the interaction, if any, between the carcinogenic effects of the two viruses is uncertain. Equal numbers of published studies have reported no risk interaction or a synergistic risk interaction. These conflicting results are explained by the rarity of concurrent infection with HBV and HCV in individuals without clinically evident liver disease, which severely limits the ability to accurately estimate the hepatocarcinogenic risk of dual infection compared with that of either infection alone. In an attempt to circumvent this difficulty, two meta-analyses have been performed, one based on studies published from a number of countries and the other on studies confined to Chinese patients. Both analyses concluded that a synergistic carcinogenic interaction existed between the two viruses and that the increased risk was super-additive but not multiplicative. If confirmed, this risk interaction will occur against a background of negative confounding effects on viral replication between HBV and HCV, which may be reciprocal. The mechanisms responsible for the carcinogenic interaction between the viruses are unknown. One possibility is that the increased incidence of cirrhosis with concurrent HBV and HCV infections acts as an even more potent tumour promoter than occurs with either virus alone. Synergism between the direct hepatocarcinogenic effects of the two viruses is another possible mechanism, but proof will have to await a fuller understanding of the pathogenetic mechanisms involved with the individual viruses. [source] Double gastric infection with Helicobacter pylori and non- Helicobacter pylori bacteria during acid-suppressive therapy: increase of pro-inflammatory cytokines and development of atrophic gastritisALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2001S. Sanduleanu Background: Long-term acid suppression may accelerate the development of atrophic gastritis in Helicobacter pylori -positive subjects. The pathogenetic mechanism remains unclear. Aim: To test the hypothesis that gastric double infection with H. pylori and non -H. pylori bacterial species,during acid suppression,may result in an enhanced inflammatory response, contributing to the development of atrophic gastritis. Patients and methods: A consecutive series of patients with gastro-oesophageal reflux disease undergoing treatment with proton pump inhibitors (n=113) or histamine2 -receptor antagonists (H2 -RAs) (n=37), and 76 non-treated dyspeptic controls were investigated. Gastric mucosal H. pylori and non- H. pylori bacteria, histological gastritis, H. pylori serology, and circulating interleukin (IL)-1,, IL-6, and IL-8 were examined. Results: Patients on acid suppression with either proton pump inhibitors or H2 -RAs had a similar prevalence of H. pylori infection to the controls, but a higher prevalence of non- H. pylori bacteria (61% and 60% vs. 29%, P < 0.0001 and P < 0.002). Both the presence of H. pylori and non- H. pylori bacteria were independent risk factors of atrophic gastritis (antrum: relative risks (RRs), 10.1 and 5.07; corpus: RRs, 11.74 and 6.38). A simultaneous presence of H. pylori and non- H. pylori bacteria was associated with a markedly increased risk of atrophic gastritis (antrum: RR, 20.25; corpus: RR, 20.38), compatible with a synergistic effect. Furthermore, the simultaneous presence of both types of bacteria was associated with higher cytokine levels than in patients without any type of bacteria. This increase was also greater than in patients with H. pylori infection alone (P < 0.001, for both IL-1, and IL-8). Summary and conclusions: H. pylori -positive patients on long-term acid inhibition displayed three features: non- H. pylori bacterial growth; increased cytokine levels; and a higher risk of atrophic gastritis. We suggest that double infection with H. pylori and non- H. pyloribacteria is a major factor in the development of atrophic gastritis during gastric acid inhibition. [source] Abomasal lymph node responses to Haemonchus contortus intestinal antigens established in kid goats by infection or immunization with intestinal antigensPARASITE IMMUNOLOGY, Issue 2 2003Douglas P. Jasmer SUMMARY Immune responses to Haemonchus contortus intestinal antigens were evaluated using abomasal lymph node (ALN) lymphocytes from kid goats protected against challenge infection by immunization with parasite intestinal antigen, and from kids that were challenged after immunization with ovalbumin. ALN lymphocytes from the intestinal antigen-immunized group produced significantly higher antibody levels against intestinal antigens than the ovalbumin group, supporting the theory that immunization contributed to that ALN response. In contrast, intestinal lysates and membrane enriched preparations from intestinal cells stimulated significant proliferation of ALN lymphocytes in both groups. The proliferation was antigen-dependent, since intestinal antigens failed to stimulate proliferation in ALN lymphocytes from unimmunized and uninfected kids. For both the intestinal antigen and ovalbumin immunized groups, CD4+ T lymphocytes predominated in ALN lymphocytes that were stimulated to proliferate by intestinal antigens. The results indicate that H. contortus infection alone can induce ALN lymphocyte responses to intestinal antigens. In contrast to ALN lymphocyte responses, serum antibody against intestinal antigens was generally low to undetectable in ovalbumin-immunized kids following infection. Abomasal mucus from an H. contortus infected lamb was probed with a monoclonal antibody that binds to a periodate sensitive determinant on numerous H. contortus intestinal membrane and secreted proteins. Numerous bands of reactivity were detected, indicating that multiple parasite intestinal antigens were released into abomasal mucus during infection. The results, challenge the general concept that H. contortus intestinal antigens are ,hidden' from the host immune system during an infection. On the contrary, parasite intestinal proteins may be relatively abundant antigens presented to the host during infection. In addition, ALN T lymphocytes appear to provide a more sensitive measure than serum antibody to detect presentation of these antigens to the host immune system. [source] Evaluation of Risk Score Algorithms for Detection of Chlamydial and Gonococcal Infections in an Emergency Department SettingACADEMIC EMERGENCY MEDICINE, Issue 2 2008Alia A. Al-Tayyib PhD Abstract Objectives:, To develop and evaluate screening algorithms to predict current chlamydial and gonococcal infections in emergency department (ED) settings and assess their performance. Methods:, Between 2002 and 2005, adult patients aged 18 to 35 years attending an urban ED were screened for Chlamydia trachomatis (Ct) and Neisseria gonorrhoeae (GC) and completed a brief demographic and behavioral questionnaire. Using multiple unconditional logistic regressions, the authors developed four separate predictive models and applicable clinical risk scores to screen for infection. They developed models for females and males separately, for Ct and GC infections combined, and for Ct infection alone. The sensitivities and specificities of the clinical risk scores at different cutoffs were used to examine performance of the algorithms. Results:, Among 5,537 patients successfully screened for Ct and GC, the overall prevalence of infection was 9.6%. Age was the strongest predictor of infection. Adjusting for other predictors, the prevalence odds ratio (POR) was 2.2 (95% confidence interval [CI] = 1.7 to 2.8) for Ct and GC combined and 2.9 (95% CI = 2.1 to 4.1) for Ct alone comparing females 25 years and younger to females older than 25 years. Among males, the association was stronger with an adjusted POR of 3.3 (95% CI = 2.3 to 4.7) for Ct and GC combined and 3.2 (95% CI = 2.1 to 4.7) for Ct infection alone. Conclusions:, If the decision to incorporate Ct and GC screening into routine ED care is made, age alone appears to be a sufficient screening criterion. [source] Can cocaine abuse exacerbate the cardiac toxicity of human immunodeficiency virus?CLINICAL CARDIOLOGY, Issue 3 2001Geetha Soodini M.D. Abstract Both cocaine use and human immunodeficiency virus (HIV) infection alone have been associated with an increased incidence of cardiac dysfunction. Concomitant exposure to cocaine and HIV infection may exacerbate the cardiac toxicity of either agent alone, a hypothesis that is examined in this review article. A possible unifying hypothesis based on enhancement of adrenergic stimulation is proposed. [source] | |||||||||||||