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Lisa Hall Zimmerman,
James G Tyburski,
Jerry Glowniak,
Rohit Singla,
Todd Lavery,
Michael Nailor,
Jerry Stassinopoulus,
Kaleford Hong,
Surendra Barshikar,
Heather S Dolman, Alfred E Baylor,
Robert F Wilson
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ABSTRACT: Appropriate antibiotic therapy and prompt drainage are essential for optimal results with abdominal abscesses.
In this prospective study, 47 abdominal abscesses from 42 patients over 2 years who had percutaneous drainage were evaluated. Antibiotic concentrations were evaluated from the abscess fluid and correlated with clinical and microbiologic cure.
Only 23% of patients had appropriate antibiotic selection with optimal concentrations for the bacteria recovered. Piperacillin/tazobactam, cefepime, and metronidazole provided adequate concentrations in all except the largest abscesses, whereas fluconazole required higher doses in all abscesses. Vancomycin and ciprofloxacin levels were inadequate in most abscesses. With gram-negative aerobes, the use of appropriate antibiotics resulted in a relatively higher incidence of presumed eradication (100% [4 of 4] vs 75% [9 of 12], P = .26). With ≥ 3 organisms identified, clinical failure was significant (58% vs 13%, P = .01).
For optimal treatment, abdominal abscesses require prompt drainage and properly selected antibiotics at adequate doses. Essential information can be obtained from abscess cultures and their antibiotic concentrations.
American journal of surgery 03/2011; 201(3):348-52; discussion 352. · 2.36 Impact Factor
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The American surgeon 07/2010; 76(7):E90-1. · 1.28 Impact Factor
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ABSTRACT: The incidence of soft tissue infections from antimicrobial-resistant pathogens is increasing. This study evaluated the epidemiology of operatively drained soft tissue abscesses.
This retrospective study evaluated 1,200 consecutive patients from 2002 to 2008 who underwent incision and drainage (I&D) in the main operating room. Patients were excluded for perirectal or hidradenitis infections.
Of 1,200 consecutive cases with an I&D, 1,005 patients had intraoperative cultures. The 1,817 positive isolates included gram-positive aerobes (1,180 [65%]), gram-negative aerobes (207 [11%]), anaerobes (416 [23%]), and fungi (14 [1%]). The most prevalent organism was Staphylococcus aureus, 30% (536), with 80% (431) being methicillin-resistant S aureus (MRSA). MRSA was the predominant organism in all except the breast abscesses. Anaerobes were identified primarily in the breast in diabetics, and in trunk and extremity abscesses in intravenous drug users. The most frequently prescribed empiric antibiotic was ampicillin/sulbactam (66%). The initial empiric antibiotic did not cover MRSA (82%; P < .001), resistant gram-negative aerobes (24%), and anaerobes (26%).
Gram-positive aerobes plus anaerobes represented approximately 80% of the pathogens in our series, with the anaerobic rates being underestimated. Empiric antibiotics should cover MRSA and anaerobes in patients with superficial abscesses drained operatively.
Surgery 10/2009; 146(4):794-8; discussion 798-800. · 3.10 Impact Factor
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ABSTRACT: The objective of these studies was to develop conjunctival epithelial cell lines for investigation of antigen translocation across a mucosal barrier. Conjunctival epithelial cells from Fischer 344 rats were immortalized with pSV3(neo) resulting in two cell lines--CJ4.1A and CJ4.3C. Each formed confluent cell layers with epithelial morphology when grown on permeable membrane filters. They expressed the SV40 T antigen, the conjunctiva-specific cytokeratin 4, the goblet cell-specific cytokeratin 7 and were negative for the corneal epithelial cell-specific cytokeratin 12. The cell lines have been in culture for over 60 passages, and the population doubling times were 22+/-7h for CJ4.1A and 23+/-9h for CJ4.3C. When grown on Transwell membranes, each cell line achieved a transepithelial electrical resistance of 600-800 Omega cm2 by 3-4 days and maintained a high resistance for several days. Both cell lines expressed zona occludens-1 at confluence. At 24h following addition of 250 microg of FITC-labeled ovalbumin to the apical chambers, 15+/-6 microg could be detected in the basal chamber of CJ4.1A and 6+/-1 microg in the basal medium of CJ4.3C. In contrast, 82+/-6 microg was detected in the lower chambers of cell-free Transwells. Similarly, Transwells containing confluent CJ4.1A or CJ4.3C cells impeded passage of 0.1 microm diameter polystyrene microspheres (5+/-1% and 4+/-1%, respectively, of the apical input), compared to 26+/-6% of the input microspheres recovered from the basal chambers of cell-free Transwells. Pretreatment with 4mM EGTA for 10 min caused an increase in OVA-FITC translocation across CJ4.3C cells. Incubation in the presence of 4mM EGTA significantly increased OVA-FITC translocation across both cell lines, relative to untreated cell layers. Morphological and functional characterization indicates that these cells provide a useful experimental tool to assess strategies for enhancing transepithelial antigen uptake.
Experimental Eye Research 03/2007; 84(2):323-31. · 3.26 Impact Factor
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ABSTRACT: Apoptosis is essential for the regulation of cell number and function of intestinal epithelial cells but may contribute to intestinal barrier failure after shock and other low-flow conditions to the gut.
Caco2 intestinal cell monolayers were challenged with recombinant tumor necrosis factor (TNF). In a second group of experiments, Caco2 cells were exposed to bacteria and/or hypoxia followed by reoxygenation. Apoptosis was detected using annexin-V propidium-iodide staining. Cell culture supernatants were also obtained in the second group of experiments and TNF levels quantitated. Monolayer integrity was assessed by measurement of paracellular permeability and transepithelial electrical resistance.
Apical but not basal recombinant TNF increased Caco2 apoptosis. Exposure to either bacteria alone or hypoxia/reoxygenation alone did not increase apoptosis; however, the combined insults significantly increased apoptosis. The increased apoptosis occurred in a delayed fashion in both groups. TNF was released in a polar fashion, and the greatest levels were noted after exposure to both bacteria and hypoxia-reoxygenation. There was also an increase in paracellular permeability in this group; however, no change in transepithelial electrical resistance was noted. The effects on apoptosis and permeability were abrogated by anti-TNF antibodies.
Intestinal epithelial cell apoptosis contributes to barrier failure after shock conditions and is related to augmented TNF release.
The Journal of trauma 06/2005; 58(5):995-1001. · 2.48 Impact Factor
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ABSTRACT: Secretory immunoglobulin A (SIgA) is the principal immunologic defense of respiratory and other mucosal surfaces in the body. SIgA is relatively stable in mucosal secretions. However, cleavage of SIgA by bacterial proteases might render it immunologically inactive and thus contribute to the development of pneumonia as well as other infections. Bacterial species and infection sites might be important in the expression of bacterial protease activity and serve as the impetus to this study.
Bacterial isolates from respiratory and nonrespiratory sites were incubated with SIgA in vitro. SIgA degradation was determined by size exclusion ultrafiltration and gel electrophoresis.
IgA protease activity was evident in gram-negative but not gram-positive respiratory isolates. Gram-negative isolates from nonrespiratory sources did not exhibit IgA protease activity.
Expression of IgA protease activity might be important in the development and subsequent outcome of gram-negative pneumonia in the patient in the surgical intensive care unit.
Surgery 11/2004; 136(4):937-43. · 3.10 Impact Factor
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ABSTRACT: Clinical data indicate that gut perfusion deficits must be rectified within 24 hours after traumatic injury to decrease organ failure and death. Ischemia/reperfusion injury to the gut causes enterocyte apoptosis (Apo), which may contribute to intestinal barrier failure. The temporal response of enterocyte Apo to acidosis and hypoxia/reoxygenation (H/R) in vitro is unknown. The purpose of this study was to examine the effect of various time points of acidosis or H/R on enterocyte apoptosis and monolayer integrity in an in vitro model.
Caco-2 cell monolayers were made acidic (Dulbecco's modified Eagle's medium, pH 6.9) by hydrochloric acid or exposed to 95% nitrogen/5% carbon dioxide (hypoxia) and then 21% oxygen (reoxygenation). Escherichia coli C-25 were added to the apical media in subsets. Apo and necrosis were quantified by flow cytometry. Permeability was determined by fluorescein isothiocyanate-dextran. Transepithelial electrical resistance (TEER) indexed monolayer.
Extracellular acidosis and C-25 significantly increased apoptosis of Caco-2 cells at 18 hours (extracellular acidosis [EC] + C-25, 14.5 +/- 3.0; control, 3.8 +/- 0.8; p < 0.001 by analysis of variance). Similarly, the H/R + C-25 group showed a significant increase in apoptosis at 12 hours (H/R + C-25 vs. control, 22.86 +/- 2.12 vs. 3.74 +/- 0.7; p < 0.001 by analysis of variance). The permeability difference was not significant for EC + C-25 versus control at 18 hours (0.68 +/- 0.25 vs. 0.43 +/- 0.0.0.36, respectively; p > 0.05). The H/R + C-25 group had a profound increase in permeability over control at 12 hours (10.8 +/- 0.5 vs. 2.1 +/- 0.3, respectively; p < 0.001). The TEER was significantly lowered for EC versus control at 18 hours (458 +/- 1.5 vs. 468 +/- 8.2) and at 0, 6, and 18 hours for EC + C-25 (409 +/- 28.1, 443 +/- 16.8, and 438 +/- 8.9 vs. 455 +/- 6.5, 467 +/- 6.5, and 469 +/- 8.2, respectively). There was no significant change in the H/R and H/R + C-25 groups.
Synergism of H/R or tissue acidosis and bacteria caused increased Apo, TEER, and permeability in vitro.
The Journal of trauma 09/2003; 55(2):241-7; discussion 247-8. · 2.48 Impact Factor
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ABSTRACT: Tissue oxygenation is a critical factor in host defense against bacteria. Gut mucosal tissue oxygenation (partial pressure of O2) is normally low putting the gut at risk of invasion by luminal microbes. Secretory immunoglobulin (Ig) A (sIgA) is the principal immune defense at mucosal surfaces. The protective effect of IgA under low oxygen conditions is unknown. We studied the interaction of varying O2 environments and sIgA on protection against bacterial invasion in our in vitro model. Cell monolayers of Madin-Darby canine kidney (MDCK) cells transfected with the cDNA for polymeric immunoglobulin receptor were established in a two-chamber cell culture system. A commensal strain of Escherichia coli (10(8) colony-forming units) was added to the apical medium and cell cultures were placed in either a 5, 21, or 95 per cent O2 environment at 37 degrees C. Polyclonal sIgA (100 microg/mL) was added to the apical chamber in subsets. Basal medium was sampled at intervals and bacterial translocation quantitated. The cell monolayers of MDCK transfected cells then had 100 microg/mL IgA added to the basal compartment at 4 degrees C for 2 hours followed by various oxygen environments for 90 minutes. Afterwards apical medium was removed at one, 3, and 12 (overnight) hours. The bacterial translocation data showed a significance increase in translocation with hypoxia. Both increased oxygen and IgA abrogated these effects significantly. The transcytosis of IgA was increased during hypoxic conditions. Normal and hyperoxic conditions did not produce any significant difference in IgA transcytosis. We conclude that O2 and sIgA are protective against bacterial invasion at epithelial surfaces. Effects to either boost O2 delivery to the gut or enhance mucosal IgA production and delivery may be protective in the critically ill surgical patient.
The American surgeon 04/2003; 69(3):231-7; discussion 237. · 1.28 Impact Factor
