Outcome of perforated necrotizing enterocolitis in the very low-birth weight neonate may be independent of the type of surgical treatment.

Perforated necrotizing enterocolitis (NEC) in the low-birth weight infant is now one of the most common surgical problems encountered in contemporary neonatal intensive care units. However, morbidity and mortality from NEC remain high, and the optimal surgical management of these infants remains controversial. Currently few data exist comparing the factors influencing outcome in very low-birth weight infants with perforated NEC treated by either local drainage or exploration. We hypothesize that survival of very low-birth weight neonates with perforated NEC may be more dependent on clinical status than on treatment modality. We present our experience treating a large cohort of infants weighing less than 1000 g with perforated NEC. A retrospective cohort study describes our experience with perforated NEC in very low-birth weight infants in a Level III neonatal intensive care unit. Between January 1991 and May 1998 a total of 70 newbo infants weighing less than 1000 g were evaluated and managed for perforated NEC. Comorbid factors were identified and calculated for each infant. Primary treatment was either local drainage or laparotomy. Statistical analysis was performed by Student's t test and multiple logistic regression. A multiple logistic regression model examined factors (comorbidities, number of comorbidities, and mode intervention) influencing outcome. A Kaplan-Meier survival analysis comparing survival versus number of comorbidities was performed. Twenty-two infants with an average weight of 679 g were treated by local drainage. Forty-eight infants with an average weight of 756 g were treated with exploratory laparotomy. Infants treated by local drainage had a higher cumulative number of comorbid factors (5.2+/-0.50 vs 3.7+/-0.29; P < 0.05) than those managed by operative exploration. Fourteen infants (63%) initially undergoing local drainage for perforated NEC survived. Of the 48 infants 36 operated on survived (75%). No single factor or combination of any comorbid factors was predictive of outcome. The total number of comorbidities for each neonate did reach statistical significance (P < 0.05). A greater likelihood of death was associated with a higher number of comorbidities. Survival with four or fewer comorbidities was 84 per cent, whereas survival with greater than six comorbidities was 30 per cent. The mean number of comorbidities was greater for drainage than for surgery, and for the same number of comorbidities the probability of survival tended to be greater for those treated with drainage than for those undergoing surgery. Multiple logistic regression analysis identified the total number of comorbidities as affecting outcome rather than treatment choice. This suggests therefore that selection of therapeutic options for the patient requires evaluating all factors that may impact survival rather than applying a single treatment strategy for all patients.

Laparoscopic diagnosis and management of ovarian torsion in the newborn.

BACKGROUND AND OBJECTIVES: The application of laparoscopic techniques in the surgical management of neonatal ovarian cysts is proving valuable both as a diagnostic tool and a potential therapeutic intervention. We report the successful management of a prenatally diagnosed ovarian cyst in a newborn female and provide operative evidence for the presumptive etiology of the cyst. METHODS AND RESULTS: A prenatally diagnosed ovarian cyst was managed using 5 mm laparoscopic instruments in a newborn female. The prenatal ultrasonographic and operative findings are consistent with in utero adnexal torsion with subsequent autoamputation and cystic degeneration of the ovary. The orphaned ovarian cyst was removed from the infant's abdominal cavity by enlarging the camera port incision. DISCUSSION: The application of laparoendoscopic procedures in infants and children continues to evolve with the availability, of microinstrumentation and increasing experience among pediatric surgeons. This approach may prove valuable in the diagnosis and management of prenatally diagnosed ovarian cysts. In addition, further insight into the etiology of congenital ovarian cysts may be obtained. The safety and efficacy of this approach in these infants remains to be fully evaluated.

Transcriptional arrest of the human E-selectin gene.

BACKGROUND: E-selectin transcription requires binding of transcription factors, NF-kappaB, ATF-2, and HMG-I(Y). Here we characterize the mechanism responsible for the transcriptional downregulation of E-selectin expression. MATERIALS AND METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with TNF-alpha for 24 h. HUVEC E-selectin expression was measured by enzyme-linked immunosorbent assay, Northern blotting, and nuclear run-on assays, and NF-kappa B was assessed by electrophoretic gel mobility shift assays (EMSAs). RESULTS: (1) E-selectin surface expression peaked at 4 h and then diminished over the next 20 h. (2) Transcription of E-selectin began within 1 h of TNF-alpha exposure and ceased by 8 h, despite continuous stimulation of HUVECs with TNF-alpha. (3) EMSAs revealed persistent binding activity of NF-kappa B proteins to two NF-kappa B-binding sites during 24 h of continuous stimulation with TNF-alpha. However, binding activity of proteins that recognize a third NF-kappa B element, -126 to -116 bp from the transcription start site, was lost after 4 h during 24 h of continuous stimulation with TNF-alpha; ATF-2 binding was unchanged over 24 h stimulation with TNF-alpha. CONCLUSION: The termination of E-selectin expression is controlled at the level of transcription, with loss of protein-DNA interactions at only one of three NF-kappa B-binding sites in the E-selectin promoter.

CD14-dependent activation of human endothelial cells by Bacteroides fragilis outer membrane.

We studied the capacity of isolated Bacteriodes fragilis outer membrane, B. fragilis NCTC9343 lipopolysaccharide (LPS; endotoxin), and B. fragilis NCTC9343 capsular polysaccharides to activate human umbilical vein endothelial cell (HUVEC) monolayers. To assess HUVEC activation, E-selectin expression was measured by enzyme-linked immunosorbent assay (ELISA), Northern blot analysis for E-selectin-specific mRNA, and electrophoretic gel mobility shift assay (EMSA) for NF-kappa B, a transcription factor necessary for E-selectin gene activation. Exposure of HUVECs to B. fragilis outer membrane fractions, separated from other components of the B. fragilis cell wall by isopycnic, sucrose gradient centrifugation, significantly increased surface expression of E-selectin and induced functional endothelial cell-dependent leukocyte adhesion. B. fragilis outer membranes induced translocation of NF-kappa B to HUVEC nuclei and accumulation of E-selectin mRNA in HUVEC cytoplasm. E-selectin expression induced by B. fragilis outer membranes was not blocked by polymixin B. In contrast, E-selectin expression induced by outer membrane fractions purified from E. coli was competitively inhibited by polymixin B. Neither purified B. fragilis LPS, a prominent constituent of the outer membrane, nor purified B. fragilis capsular polysaccharides induced HUVEC activation. Two different monoclonal antibodies directed against human CD14 completely inhibited B. fragilis outer membrane-induced NF-kappa B activation, E-selectin transcription, and E-selectin surface expression. We conclude that the outer membrane component of the B. fragilis cell wall contains a proinflammatory factor(s), that is not LPS, which induces human endothelial cell activation by a soluble CD14-dependent mechanism.

Hypothermia inhibits human E-selectin transcription.

During endothelial cell activation, the formation and expression of E-selectin require transcriptional activation of the E-selectin gene, mediated by the coordinated action of several transcription factors and cis-acting elements in its 5'-flanking region. It is reported that in vitro hypothermia (25 degrees C) transiently inhibits transcriptional activation and surface expression of E-selectin as well as neutrophil adherence to cultured human umbilical vein endothelial cells (HUVECs) treated with lipopolysaccharide (LPS), interleukin-1 (IL-1), or tumor necrosis factor (TNF). Rewarming HUVECs treated with LPS, IL-1, or TNF to 37 degrees C restores E-selectin transcript accumulation, E-selectin surface expression, and neutrophil adherence to HUVECs at levels equivalent to similarly treated HUVECs maintained at 37 degrees C continuously. Despite the absence of detectable E-selectin transcription at 25 degrees C, activation of the transcription factor NF-kappaB still occurred in HUVECs treated with LPS, IL-1, or TNF, indicating that signal transduction was not blocked by hypothermia. It is concluded that neutrophil adherence to activated endothelium mediated by E-selectin is reversibly inhibited by hypothermia. The protective effect of hypothermia clinically (e.g., cardiopulmonary bypass) may, in part, be mediated by transiently inhibiting the expression of an endothelial cell activation phenotype.

Necrotizing soft tissue infections: obstacles in diagnosis.

BACKGROUND: This study was done to identify obstacles in the early diagnosis and treatment of necrotizing soft tissue infections. STUDY DESIGN: A ten-year retrospective case series was analyzed. RESULTS: Data from 29 patients were analyzed. Among patients undergoing early operation within 24 hours of admission (n = 17) there was one death (6 percent mortality rate); survivors averaged 2.9 operations per patient. By comparison, of patients with delayed operation (n = 12) three died (25 percent mortality rate) and there were 3.6 operations per patients. Positive fine-needle aspiration (FNA) of suspicious lesions, demonstrating either pus or bacteria by Gram's stain, led to early operation in 80 percent of patients tested. Patients with soft tissue gas on radiographs were more likely to undergo early operation (58 percent). Delayed operation was more common in the absence of radiographic findings. All patients admitted to nonsurgical services had delayed operations. CONCLUSIONS: Suspected necrotizing soft tissue infections require prompt surgical evaluation and early operative exploration. Early operation with definitive surgical therapy initiated within 24 hours of admission is associated with decreased mortality rates. Negative FNA findings, nondiagnostic radiographs, and admission to a nonsurgical service correlate with delay in definitive operative intervention.

Activation of human endothelial cells by viable or heat-killed gram-negative bacteria requires soluble CD14.

In response to bacterial lipopolysaccharides (LPS; endotoxin), endothelial cells are converted to an activation phenotype expressing both proinflammatory and procoagulant properties that include the induction of leukocyte adhesion molecules and tissue factor expression. LPS-induced endothelial cell activation requires a soluble form of the monocyte LPS receptor, sCD14. We evaluated the capacity of multiple strains of gram-negative and gram-positive bacteria to induce endothelial E-selectin and tissue factor expression through sCD14-dependent pathways with cultured human umbilical vein endothelial cells (HUVE). Both viable and heat-killed gram-negative bacteria (Bacteroides fragilis, Enterobacter cloacae, Haemophilus influenzae, and Klebsiella pneumoniae) but not viable or heat-killed gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis, and Streptococcus pneumoniae) induced prominent E-selectin surface expression detected by enzyme-linked immunosorbent assay. Tissue factor activity on HUVE, indicated by factor X activation, was induced in response to gram-negative bacteria but not in response to gram-positive bacteria. Gram-negative bacteria induced transcriptional activation in HUVE, indicated by the appearance of E-selectin-specific mRNA and by the demonstration of activation of NF-kappa B, a trans-activating factor necessary for E-selectin and tissue factor gene transcription. In contrast, neither E-selectin mRNA nor activation of NF-kappa B was detected in HUVE treated with gram-positive bacteria. Endothelial cell activation by gram-negative bacteria in each of these assays was inhibited with a monoclonal antibody (60bd) against CD14. Furthermore, CHO-K1 cells, transfected with human recombinant CD14, responded to all strains of gram-negative bacteria (viable or heat killed), indicated by CHO-K1 NF-kappa B activation. We conclude that gram-negative bacteria induce endothelial cell activation through a common sCD14-dependent pathway.

A protein kinase C agonist, selective for the beta I isozyme, induces E-selectin and VCAM-1 expression on HUVEC but does not translocate PKC.

A protein kinase C (PKC) agonist selective for the beta I isozyme, 12-deoxyphorbol 13-phenylacetate 20-acetate (dPPA), induced NF-kappa B-like binding activity and surface expression of E-selectin and VCAM-1 in human umbilical vein endothelial cells (HUVEC), similar to the effects of tumor necrosis factor-alpha (TNF-alpha). Induction of E-selectin and VCAM-1 expression by dPPA was completely inhibited by the PKC inhibitors staurosporine and Ro31-7549. The PKC inhibitors also reduce TNF-alpha-induced VCAM-1 expression. However, neither dPPA nor TNF-alpha translocated PKC from the cytosolic to the plasma or nuclear membrane particulate fractions in HUVEC. These results indicate that activation of the beta I PKC isozyme is sufficient for expression of E-selectin and VCAM-1, and suggest that PKC may mediate the effects of TNF-alpha and dPPA without requiring the translocation normally associated with activation of PKC.

Diagnosis and management of pericardial abscess in trauma patients.

Pericardial infection is an uncommon clinical entity after traumatic injury. Although invasive intervention is rarely necessary for mild pericardial inflammation, pericardial abscess can be life-threatening. The charts of 27 patients with pericarditis requiring management in the intensive care unit and/or invasive intervention at Harborview Medical Center during a 10-year period were reviewed. Six cases of trauma-related pericarditis were identified, including three cases of pericardial abscess following torso trauma without initial cardiac or pericardial injury. Pericardial abscess following trauma was associated with the sepsis syndrome and multiple system organ failure (MSOF) in all patients. Computed tomography and pericardiocentesis were useful diagnostic adjuncts. All patients required thoracotomy for pericardial drainage and pericardiectomy. Successful surgical management of pericardial abscess contributed to the resolution of sepsis, multiple end-organ dysfunction and, ultimately, patient survival in all cases. We conclude that pericardial abscess, although rare, should be considered a potential occult site of sepsis capable of driving MSOF in trauma patients. Expedient diagnosis and surgical drainage are essential for successful patient outcome.