Enteral nutritional supplementation with key nutrients in patients with critical illness and cancer: a meta-analysis of randomized controlled clinical trials.
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OBJECTIVE: To conduct a meta-analysis of 11 randomized controlled trials comparing enteral nutritional support supplemented with key nutrients versus standard enteral nutritional support to determine effects on morbidity and mortality rates and hospital stay. BACKGROUND DATA: Recent studies have shown that malnutrition occurs in up to 30% of patients undergoing gastrointestinal surgery, resulting in an increased risk of postoperative complications and death. With the realization that key nutrients can modulate inflammatory, metabolic, and immune processes, enteral nutritional regimens (supplemented with large amounts of key nutrients) have been developed for clinical use. METHODS: Eleven prospective, randomized controlled trials evaluating 1009 patients treated with combinations of key nutrients (Impact, Immun-Aid) were evaluated. Outcome measures examined were the incidences of pneumonia, infectious complications, and death, and length of hospital stay. Meta-analyses were undertaken to obtain the odds ratio and 95% confidence interval for incidences of infectious complications, pneumonia, and death, and the weighted mean difference and 95% confidence interval for length of hospital stay. RESULTS: The provision of nutritional support supplemented with key nutrients to patients with critical illness resulted in a decrease in infectious complications when compared with patients receiving standard nutritional support and a significant reduction in overall hospital stay. Similar results were documented in patients with gastrointestinal cancer. However, there were no differences between patient groups for either pneumonia or death. CONCLUSIONS: This meta-analysis has demonstrated that nutritional support supplemented with key nutrients results in a significant reduction in the risk of developing infectious complications and reduces the overall hospital stay in patients with critical illness and in patients with gastrointestinal cancer. However, there is no effect on death. These data have important implications for the management of such patients. (+info)
Imaging experimental intraabdominal abscesses with 99mTc-PEG liposomes and 99mTc-HYNIC IgG.
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OBJECTIVE: To evaluate the accuracy of technetium-99m-labeled polyethylene glycol-coated liposomes (99mTc-PEG liposomes) and technetium-99m-labeled nonspecific human immunoglobulin G (99mTc-HYNIC IgG) for the scintigraphic detection of experimental intraabdominal abscesses in comparison with that of a standard agent, gallium-67 citrate. BACKGROUND: Scintigraphic imaging techniques can be very useful for the rapid and accurate localization of intraabdominal abscesses. Two newly developed radiolabeled agents, 99mTc-PEG liposomes and 99mTc-HYNIC IgG, have shown to be excellent agents for imaging experimental focal infection, but have not yet been studied in the detection of abdominal abscesses. METHODS: Intraabdominal abscesses were induced in 42 rats using the cecal ligation and puncture technique. Seven days later, randomized groups of rats received 99mTc-PEG liposomes, 99mTc-HYNIC IgG, or 67Ga citrate intravenously. The rats were imaged up to 24 hours after the injection. The biodistribution of the radiolabel was determined by counting dissected tissues ex vivo. Macroscopic intraabdominal abnormalities and focal uptake on the images were independently scored on a semiquantitative scale. RESULTS: 99mTc-PEG liposomes provided the earliest scintigraphic visualization of the abscess (as soon as 2 hours after the injection vs. 4 hours for the other two agents). Liposomes, IgG, and gallium all showed similarly high absolute uptake in the abscess. Focal uptake of liposomes and gallium correlated best with the extent of the macroscopic abnormalities. CONCLUSIONS: 99mTc-PEG liposomes and 99mTc-HYNIC IgG performed at least as well as the standard agent, 67Ga citrate, in the detection of experimental intraabdominal abscesses, with obvious advantages such as lower radiation exposure and more favorable physical properties. Of the two technetium agents, the liposomes seemed to be superior, providing the earliest diagnostic image and the best correlation with the inflammatory abnormalities. In addition, the preferential localization of radiolabeled PEG liposomes holds promise for targeted delivery of liposome-encapsulated drugs. (+info)
IL-2 mediates protection against abscess formation in an experimental model of sepsis.
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Little is known regarding the mechanism by which T cells control intraabdominal abscess formation. Treating animals with polysaccharide A (PS A) from Bacteroides fragilis shortly before or after challenge protects against abscess formation subsequent to challenge with different abscess-inducing bacteria. Although bacterial polysaccharides are considered to be T cell-independent Ags, T cells from PS A-treated animals mediate this protective activity. In the present study, we demonstrate that CD4+ T cells transfer PS A-mediated protection against abscess formation, and that a soluble mediator produced by these cells confers this activity. Cytokine mRNA analysis showed that T cells from PS A-treated animals produced transcript for IL-2, IFN-gamma, and IL-10, but not for IL-4. The addition of IL-2-specific Ab to T cell lysates taken from PS A-treated animals abrogated the ability to transfer protection, whereas the addition of Abs specific for IFN-gamma and IL-10 did not affect protection. Finally, administration of rIL-2 to animals at the time of bacterial challenge prevented abscess formation in a dose-dependent manner. These data demonstrate that PS A-mediated protection against abscess formation is dependent upon a CD4+ T cell-dependent response, and that IL-2 is essential to this immune mechanism. (+info)
Appendix abscess: a surgical giant presenting as a geriatric giant.
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CASE REPORT: A women aged 102 years presented with falls and was found to have an atypical presentation of appendicitis. CONCLUSION: This illustrates the non-specific presentation of disease in old age and the importance of a careful medical assessment of people who have fallen. (+info)
A meta-analysis of laparoscopic versus open appendectomy in patients suspected of having acute appendicitis.
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OBJECTIVE: To determine if any significant differences exist between laparoscopic appendectomy (LA) and open appendectomy (OA). DESIGN: A meta-analysis of randomized controlled trials (RCTs) comparing LA to OA. DATA SOURCES: An extensive literature search was conducted for appropriate articles published between January 1990 and March 1997. Articles were initially retrieved through MEDLINE with MeSH terms "appendicitis" or "appendectomy" and "laparoscopy". Additional methods included cross-referencing bibliographics of retrieved articles, hand searching abstracts from relevant meetings and consultation with a content expert. STUDY SELECTION: Only RCTs published in English in which patients had a preoperative diagnosis of acute appendicitis were included. DATA EXTRACTION: The outcomes of interest included operating time, hospital stay, readmission rates, return to normal activity and complications. The Cochrane Collaboration Review Manager 3.0 was used to calculate odds ratios (OR), weighted mean differences (WMD) and 95% confidence intervals (CI). The random-effects model was used for statistical analysis. DATA SYNTHESIS: Twelve trials met the inclusion criteria. Because there were insufficient data in some trials, operating time, hospitalization and return to work were assessed in only 8 trials. Mean operating time was significantly longer with LA (WMD 18.10 minutes, 95% CI 12.87 to 23.15 minutes). There were fewer wound infections in LA (OR 0.40, 95% CI 0.24 to 0.69), but no significant differences in intra-abdominal abscess rates (OR 1.94, 95% CI 0.68 to 5.58). There was no significant difference in the mean length of hospital stay (WMD -0.16 days, 95% CI -0.44 to 0.15 days) or readmission rates (OR 1.16, 95% CI 0.54 to 2.48). However, the return to normal activity was significantly earlier with LA (WMD -5.79 days, 95% CI -7.38 to -4.21 days). Sensitivity analyses did not affect the results. CONCLUSION: This meta-analysis suggests that operating room time is significantly longer, hospital stay is unchanged but return to normal activities is significantly earlier with LA. (+info)
Inflammatory processes in a murine model of intra-abdominal abscess formation.
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Abscess formation has been viewed as a host defense strategy to contain the spread of infection. However, abscesses are also serious and life-threatening manifestations of persisting microbial infection. The initiation of abscess formation, both clinically and experimentally, involves the release of bacteria and an abscess-potentiating agent (e.g., fecal fiber or an analog) into a sterile site, with host defense mechanisms being unable to eliminate the infecting organisms. Abscess formation is aided by a combination of factors that share a common feature: impairment of phagocytic killing and hence clearance of microorganisms. These include bacterial virulence factors (e.g., capsule formation, succinic acid production); complement activation by the abscess potentiating agent; fibrin deposition; and microbial sequestration within abscess neutrophils. Recruitment of cells into the peritoneal cavity follows mast cell activation in the pathogenesis of infection: histamine and tumor necrosis factor alpha can be detected in the peritoneal cavity within minutes of challenge with an abscess-inducing mixture. However, the role of mast cells in host defense is made less clear by the finding of diminished abscess formation (but no mortality or increased morbidity) in mast-cell-depleted mice. This may indicate that mast cell products have a role in not only the initiation of an inflammatory response but also the promotion of fibrin deposition and abscess formation. (+info)
Activities of the oxazolidinones linezolid and eperezolid in experimental intra-abdominal abscess due to Enterococcus faecalis or vancomycin-resistant Enterococcus faecium.
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The in vivo effectiveness of oxazolidinones eperezolid (U-100592) and linezolid (U-100766) against one strain each of Enterococcus faecalis and vancomycin-resistant Enterococcus faecium was examined in a rat model of intra-abdominal abscess. MICs of both drugs were 2 microg/ml for each strain. At doses of 25 mg/kg of body weight twice daily intravenously or orally, linezolid produced small but statistically significant reductions in abscess bacterial density for E. faecalis. The reduction in viable cells observed would not likely be clinically relevant. Eperezolid was ineffective at this dose. At a dosage of 100 mg/kg/day, linezolid treatment led to an approximately 100-fold reduction in viable cells per gram of abscess. Against E. faecium infections, intravenous eperezolid and oral linezolid were effective, reducing densities approximately 2 log(10) CFU/g. Both oxazolidinones demonstrated activity against enterococci in this model. However, results were modest with the dosing regimens employed. (+info)
Effect of molecular size on the ability of zwitterionic polysaccharides to stimulate cellular immunity.
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The large-molecular-sized zwitterionic capsular polysaccharide of the anaerobe Bacteroides fragilis NCTC 9343, designated polysaccharide (PS) A, stimulates T cell proliferation in vitro and induces T cell-dependent protection against abscess formation in vivo. In the present study, we utilized a modification of a recently developed ozonolytic method for depolymerizing polysaccharides to examine the influence of the molecular size of PS A on cell-mediated immunity. Ozonolysis successfully depolymerized PS A into structurally intact fragments. PS A with average molecular sizes of 129.0 (native), 77.8, 46.9, and 17.1 kDa stimulated CD4+-cell proliferation in vitro to the same degree, whereas the 5.0-kDa fragment was much less stimulatory than the control 129.0-kDa PS A. Rats treated with 129.0-kDa, 46.9-kDa, and 17.1-kDa PS A molecules, but not those treated with the 5.0-kDa molecule, were protected against intraabdominal abscesses induced by challenge with viable B. fragilis. These results demonstrate that a zwitterionic polysaccharide as small as 22 repeating units (88 monosaccharides) elicits a T cell-dependent immune response. These findings clearly distinguish zwitterionic T cell-dependent polysaccharides from T cell-independent polysaccharides and give evidence of the existence of a novel mechanism for a polysaccharide-induced immune response. (+info)