Biomedical subjects

Steven D Tennenberg

Publications and source records attributed to Steven D Tennenberg.

3 recordsLinked to original sources

PubMed2004

Effects of surgical gloves on postoperative peritoneal adhesions and cytokine expression in a rat model.

BACKGROUND: Postoperative intraperitoneal adhesions are a major cause of morbidity. We studied the effects of synthetic and latex gloves, and their powders, on postoperative adhesions and cytokine expression in a rat model. METHODS: Rats underwent laparotomy and cecal abrasion. Rats were grouped based on the glove type used: synthetic powder-free (SPF), synthetic powdered (SP), latex powder-free (LPF), and latex powdered (LP). Serum cytokine (tumor necrosis factor [TNF], interleukin-1 [IL-1], and IL-6) levels were measured. Animals were killed and peritoneal adhesions were graded. RESULTS: The SPF group had no adhesions. Adhesions were increased similarly in the SP and LPF groups, and further increased in the LP group. Postoperative serum cytokine levels showed a similar pattern of increases. CONCLUSIONS: The presence of latex or powder on surgical gloves promoted increased adhesions. Serum cytokine levels correlated with the degree of adhesion formation. Strategies to use latex-free, powder-free gloves and/or limit cytokine expression may decrease peritoneal adhesions in the clinical setting.

Analysis of Variance↗

PubMed2002

Multiple heparanases are expressed in polymorphonuclear cells.

BACKGROUND: Heparan sulfate proteoglycans are complex cell surface molecules containing polysaccharides called heparan sulfate. Lysosomes, platelet granules, and neutrophils (polymorphonuclear cells) contain heparanases that degrade heparan sulfate. There are at least two groups of heparanases: connective tissue-activating-peptide (CTAP-III) and mammalian heparanase (hpa). The purpose of this study was to quantify the expression of both CTAP-III and hpa in neutrophils and their heparanase activity. MATERIALS AND METHODS: Neutrophils were isolated from whole blood, total RNA collected, and reverse transcriptase--polymerase chain reaction (RT-PCR) performed. Primers were designed for CTAP-III and hpa-1 sequences from GenBank. Neutrophil lysate underwent Western blot analysis (and quantification) with antibodies to the C-terminus of CTAP-III and the 50-kDa subunit of hpa1. Chromatography separated these components of lysate, which were then tested for heparanase activity. RESULTS: Both CTAP-III (281 bp) and hpa-1 (485 bp) messenger RNA (mRNA) were expressed equally by neutrophils with use of quantitative RT-PCR. By Western blot analysis, a CTAP-III-like protein was detected at 80 kDa, and hpa-1 was detected as a 50-kDa protein, with expression not significantly different (P > 0.05). Heparanase activity was significantly different (P < 0.0001) for the 50-kDa hpa-1 protein (1.51 x 10(-6) micromol/min) and the 80-kDa CTAP-III-like protein (0.85 x 10(-6) micromol/min). CONCLUSIONS: Human neutrophils express mRNA and protein for both a CTAP-III-like protein and hpa-1. Although expressed in similar quantity for mRNA and protein, Hpa-1 was more active as heparanase than the CTAP-III-like protein. With more than one class of heparanase in their granules, neutrophils may be able to modify different kinds of heparan sulfate chains.

Amino Acid Sequence↗

PubMed2002

Endothelium down-regulates Fas, TNF, and TRAIL-induced neutrophil apoptosis.

BACKGROUND: Neutrophil (PMN) apoptosis regulates PMN functional longevity and is integral to the resolution of inflammation. We have recently shown that PMN contact with an endothelial monolayer down-regulates spontaneous PMN apoptosis. We sought to explore endothelial-mediated down-regulation of PMN apoptosis following mediator-induced apoptosis. We tested the three known membrane-initiated, receptor-ligand apoptotic pathways: Fas, tumor necrosis factor-alpha (TNF), and TNF-related apoptosis inducing ligand (TRAIL). METHODS: PMNs were isolated from peripheral venous blood of healthy volunteers. PMNs were co-cultured in the absence and presence of a human coronary artery endothelial cell (HCAEC) monolayer for 4 h. PMNs were then stimulated with the pro-apoptotic agonists (agonistic anti-Fas IgM, TNF, and TRAIL) for one hour, followed by an assessment of apoptosis after 5 h. PMN apoptosis was measured using an acridine orange/ethidium bromide in situ fluorescent microscopy assay. Caspase 3 activity was assessed using a spectrophotometric assay. RESULTS: In addition to spontaneous PMN apoptosis, endothelial co-culture resulted in significant increases in the percentages of normal cells and decreased percentages of apoptotic cells after stimulation with agonistic anti-Fas IgM, TNF and TRAIL. Endothelial co-culture did not alter PMN caspase 3 activity. CONCLUSION: Endothelial-mediated down-regulation of PMN apoptosis is conferred after 4 h of co-culture. In addition to spontaneous apoptosis, endothelial contact down-regulated the three known membrane-initiated PMN apoptotic pathways: Fas, TNF, and TRAIL. These data imply that endothelial-mediated down-regulation of PMN apoptosis may involve defects in each apoptotic pathway or a single defect in a distal transduction or effector event common to all three pathways. Alterations in the activity of caspase 3 did not appear to serve as a mechanism for endothelial-mediated down-regulation of PMN apoptosis.

Adult↗