Major Infections (major + infections)

Distribution by Scientific Domains

Selected Abstracts

Differential expression of antimicrobial peptides in margins of chronic wounds

Stefanie Dressel
Please cite this paper as: Differential expression of antimicrobial peptides in margins of chronic wounds. Experimental Dermatology 2010; 19: 628,632. Abstract:, Skin wounds usually heal without major infections, although the loss of the mechanical epithelial barrier exposes the tissue to various bacteria. One reason may be the expression of antimicrobial peptides (AMP) of which some [human ,-defensins (hBD) and LL-37] were recently shown to support additionally certain steps of wound healing. There are no studies which have compared expression patterns of different classes of AMP in chronic wounds. The aim of our study was therefore to analyse the expression profile of hBD-2, hBD-3, LL-37, psoriasin and RNase 7 by immunohistochemistry from defined wound margins of chronic venous ulcers. We detected a strong induction of psoriasin and hBD-2 in chronic wounds in comparison with healthy skin. Except for stratum corneum, no expression of RNase 7 and LL-37 was detected in the epidermis while expression of hBD-3 was heterogeneous. Bacterial swabs identified Staphylococcus aureus and additional bacterial populations, but no association between colonization and AMP expression was found. The differential expression of AMP is noteworthy considering the high bacterial load of chronic ulcers. Clinically, supplementation of AMP with the capability to enhance wound healing besides restricting bacterial overgrowth could present a physiological support for treatment of disturbed wound healing. [source]

The development of effector and memory T cells in cutaneous leishmaniasis: the implications for vaccine development

Phillip Scott
Summary:,Leishmania major infections induce the development of a CD4+ T-helper 1 (Th1) response that not only controls the primary infection but also results in life-long immunity to reinfection. How that immunity is maintained is unknown, although because of the existence of infection-induced immunity, there has been an assumption that the development of a vaccine against leishmaniasis would be relatively easy. This has turned out not to be the case. One problem has been the finding that a large part of the immunity induced by a primary infection depends upon the presence of persistent parasites. Nevertheless, there are ample situations where immunologic memory persists without the continued presence of antigen, providing the prospect that a non-live vaccine for leishmaniasis can be developed. To do so will require an understanding of the events involved in the development of an effective protective T-cell response and, more importantly, an understanding of how to maintain that response. Here, we review work from our laboratory, describing how Th1 cells develop in L. major -infected mice, the nature of the memory T cells that provide protection to reinfection, and how that information may be utilized in the development of vaccines. [source]

Intravenous iron attenuates postvaccination anti-HBsAg titres after quadruple hepatitis B vaccination in dialysis patients with erythropoietin therapy

J.-H. Liu
Summary Background:, Anaemia in patients with end-stage renal disease (ESRD) is commonly treated with recombinant human erythropoietin (rHuEPO), often in combination with an adjuvant iron supplement. There is much evidence that rHuEPO can influence the immune response by its effect on lymphocytes. Also, iron catalyses the formation of radicals and increases the risk of major infections by negatively affecting the immune system. The relationship between antibodies to hepatitis B surface antigen (anti-HBsAg) responsiveness after hepatitis B vaccination and rHuEPO/adjuvant iron supplementation has not been reported before. Aim:, To determine the effects of subcutaneous erythropoietin and intravenous (i.v.) iron therapy on the responsiveness of anti-HBsAg after quadruple hepatitis B vaccination among ESRD patients. Methods:, Retrospective medical records were reviewed in a hospital with a tertiary teaching facility. Eighty-three ESRD patients, including 51 who underwent haemodialysis and 32 who underwent peritoneal dialysis therapy, received a quadruple recombinant hepatitis B vaccine. We investigated anti-HBsAg titres in those patients who either received rHuEPO alone (n = 50) or rHuEPO in combination with i.v. iron (n = 33). Results:, We found that the postvaccination anti-HBsAg titre was significantly lower in the rHuEPO plus i.v. iron group when compared with the group with rHuEPO alone (p < 0.05). The increment of anti-HBsAg between the initial month and the seventh month was positively correlated with therapeutic rHuEPO dosages in the group with rHuEPO alone (r = 0.303, p = 0.033). This relationship was not present in the rHuEPO with i.v. iron group (r = ,0.289, p = 0.229). Conclusions:, The levels of anti-HBsAg after hepatitis B vaccination are positively correlated with the dose of rHuEPO treatment during the vaccinated period among ESRD patients without i.v. iron supplementation. Also, i.v. iron negatively impacts the responsiveness of anti-HBsAg titre after hepatitis B vaccination in ESRD patients who have undergone rHuEPO therapy. [source]

Endpoint quantitative PCR assays for Bacteroides forsythus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans

J. D. Rudney
Background:, Conventional polymerase chain reaction (PCR) assays for periodontal pathogens are so sensitive that they detect infections of no clinical significance. Quantitative PCR (qPCR) may provide a solution to this problem. However, most qPCR systems require expensive real-time thermal cyclers. Objective:, Our goal was to develop qPCR assays which would allow endpoint quantification. Materials and methods:, 16S rRNA primers for Bacteroides forsythus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans were adapted to the AmplifluorÔ qPCR system, which incorporates fluorescein into the PCR product so that endpoint fluorescence is proportional to the original amount of template. DNA dilutions representing known numbers of cells were used as standard curves. Pooled subgingival plaques from the four deepest pockets of 21 severe adult periodontitis patients were assayed. Buccal molar supragingival plaque from 35 dental students provided healthy controls. Endpoint fluorescence was measured with a microplate reader. Results:, Optimized standard curves were linear in log,log or semilog fits over a range of 100,106 cells. Countable B. forsythus was present in all patients, with counts (as logs) from 2.4 to 7.3 (mean = 5.0), and 11 controls with counts from 2.1 to 4.5 (mean = 3.0). P. gingivalis was present in 11 patients and no controls, with counts from 2.2 to 4.7 (mean = 3.2). A. actinomycetemcomitans was present in two patients, with counts of 1.5 and 3.5. Conclusions:, AmplifluorÔ qPCR assays discriminated between plaque samples differing by one log or more, allowing major infections to be distinguished from minor ones. This approach allows high-throughput qPCR of plaque samples, using equipment available to many laboratories. [source]

Meta-analysis: antibiotic prophylaxis in elective laparoscopic cholecystectomy

Summary Background, Current guidelines do not support routine antibiotic prophylaxis during elective laparoscopic cholecystectomy. However, routine antibiotic prophylaxis for elective laparoscopic cholecystectomy is still popular in many clinical settings. Aim, To evaluate the role of antibiotic prophylaxis in elective laparoscopic cholecystectomy. Methods, Electronic databases and manual bibliographical searches (updated to April 2008) were conducted. A meta-analysis of all trials evaluating antibiotic prophylaxis in elective laparoscopic cholecystectomy was performed. Results, Fifteen trials were included, involving 2961 patients. After pooling all the trials, 48 wound infections occurred (48/2961, 1.62%), 22 in antibiotic prophylaxis group (22/1494, 1.47%) and 26 in control group (26/1467, 1.77%). The pooled odds ratio (OR) was 0.79 (95%CI: 0.44, 1.41). Four major infections occurred (4/2961, 0.14%), 3 in antibiotic prophylaxis group (3/1494, 0.20%), and one in control group (1/1467, 0.07%). The pooled OR was 2.51 (95%CI: 0.35, 17.84). Fifteen distant infections occurred (15/2961, 0.51%), six in antibiotic prophylaxis group (6/1494, 0.40%) and nine in control group (9/1467, 0.61%). The pooled OR was 0.53 (95%CI: 0.19, 1.50). Sensitivity analyses also failed to support antibiotic prophylaxis's preventive effect. Conclusions, Considering the absent role of antibiotic prophylaxis in reducing the infectious complications, we suggest that antibiotic prophylaxis is unnecessary and should not be routinely used in low-risk elective laparoscopic cholecystectomy patients. [source]

Risk Factors and Mechanisms of Preterm Delivery in Malawi

Elizabeth T. Abrams
Problem:, We examined risk factors and mechanisms of preterm delivery (PTD) in malaria-exposed pregnant women in Blantyre, Malawi. Method of study:, The human immunodeficiency virus (HIV), malaria, syphilis, and anemia were assessed in a cross-sectional study of 572 pregnant women. In a nested case,control study, chorioamnionitis (CAM) was examined; tumor necrosis factor (TNF)- ,, interleukin (IL)-6, IL-8, macrophage inflammatory protein (MIP)-1,, monocyte chemotactic protein (MCP)-1, transforming growth factor (TGF)- ,, cortisol, and corticotropin-releasing hormone were measured in placental, maternal and/or cord blood. Results:, HIV, infrequent antenatal clinic attendance, low-maternal weight, no intermittent preventive malaria therapy (IPT), and CAM were associated with PTD, while malaria was not. Of the 18 compartmental cytokine measurements, elevations in placental and/or cord IL-6 and IL-8 were associated with both CAM and PTD. In contrast, there was no overlap between the cytokines affected by malaria and those associated with PTD. Conclusions:, The HIV and CAM were the major infections associated with PTD in this study. CAM, but not malaria, causes PTD via its effect on proinflammatory cytokines. [source]

Immunologic memory in cutaneous leishmaniasis

Phillip Scott
Summary Leishmania major infections induce solid immunity to reinfection. Experimental studies in mice indicate that the CD4+ T cells responsible for this immunity include two populations: parasite-dependent T effector cells and parasite-independent central memory T (Tcm) cells. While there currently is no vaccine for leishmaniasis, the existence of a long-lived population of Tcm cells that does not require the continued presence of live parasites suggests that a vaccine that expands these cells might be efficacious. [source]