Effect of caffeic acid phenethyl ester on survival of axial pattern flaps in rats with ischaemia-reperfusion injuries.

Oxygen-derived free radicals have been implicated in the pathogenesis of tissue injury after ischaemia-reperfusion. Caffeic acid phenethyl ester (CAPE), an active ingredient of honeybee propolis, has been identified as having potent antioxidant and anti-inflammatory properties. We evaluated the ability of CAPE applied intraperitoneally in reducing tissue injury after ischaemia-reperfusion. To investigate whether treatment with CAPE modifies the concentrations of the endogenous indices of oxidant stress, we examined its effects on a model of flap ischaemia-reperfusion injury in rats. CAPE (10 micromol/kg) was given through the peritoneum before reperfusion. CAPE given intraperitoneally had an inhibitory effect on tissue injury after ischaemia-reperfusion comparable to that of a control group. The anti-inflammatory and antioxidant properties of CAPE may contribute to its suppression of tissue injury.     

T cells in the spinal cord in experimental autoimmune encephalomyelitis are matrix adherent and secrete tumor necrosis factor alpha.

We examined T cells isolated from an autoimmune tissue lesion and from lymphoid organs for their ability to secrete tumor necrosis factor-alpha (TNF-alpha) and to adhere to extracellular matrix (ECM) proteins. CD4+ T cells were obtained from spleens, popliteal lymph nodes, and spinal cords of Lewis rats that had been immunized with myelin basic protein (MBP) to induce experimental autoimmune encephalomyelitis (EAE). We now report that, irrespective of whether or not the T cells were activated with MBP or the T cell mitogen concanavalin A (ConA), the T cells isolated from the spinal cord lesions secreted greater amounts of TNF-alpha and adhered better to ECM than did T cells from the draining lymph node. Thus, the lesions of EAE concentrate a subpopulation of CD4+ T cells with enhanced ability to interact with blood vessel wall components and to secrete TNF-alpha.     

Prophylactic antibiotic use in pediatric burn units.

Prophylactic antibiotic use in childhood burns is controversial. The efficiency of antibiotic prophylaxis in 77 pediatric burn patients was evaluated. Forty-seven patients received prophylactic antibiotics (Group AP), while 30 patients received no prophylaxis (Group NP). Age, wound depth, day of admission, mechanism of burn injury, type of dressings were similar for both groups (p > 0.05). Wound infection rates were 21.3 % in Group AP and 16.7 % in Group NP (p > 0.05). S. aureus, Enterobacter spp., P. aeruginosa, and E. coli were the most common microorganisms. Patients with wound colonization and infection had a larger burned total body surface area (BTBSA) in both groups (p < 0.01). Eight patients had clinical sepsis. All but one of the septic patients were from Group AP. Associated infections of the upper and lower respiratory tract (16), urinary tract (7), and otitis media (2) were more common in Group AP. One patient died from sepsis in Group AP. Hospital stays were longer in Group AP (21.7 +/- 16.4 vs. 13.5 +/- 10 days; p < 0.05). Antibiotic prophylaxis in childhood burns does not reduce the rate of wound infection. Age, wound depth and BTBSA are not critical variables for prophylaxis. Reinforcing the use of culture-specific antibiotics for more beneficial and cost-effective results in the treatment of childhood burns is recommended.     

The role of surgery in intraabdominal Burkitt's lymphoma in children.

The role of surgery in intraabdominal Burkitt's lymphoma remains controversial and different opinions are present in the literature. In our institution, forty patients (30 boys and 10 girls) with intraabdominal Burkitt's lymphoma with ages ranging from 3 to 12 years have been treated and followed from 1989 through 2000. In ten cases, the patients underwent surgery because of their acute abdominal diseases (intestinal obstruction in 5, intussusception in 3, intestinal perforation in one, and acute appendicitis in one). The remaining thirty patients were referred to our clinic because of their abdominal masses, pain, anorexia and fatigue. Twelve children had localized tumors and total resection could be performed. There was one death in this group due to central nervous system involvement during chemotherapy. In the remaining 28 children, extensive intraabdominal diseases were detected. In four of them, debulking procedures were performed, while in 24 children only biopsies could be made; 8 of them underwent a second-look operation. In the debulking procedures group, two children were lost (50 %) due to tumorlysis and acute renal failure. In the biopsy group, there were six deaths (25 %). All patients received chemotherapy after operative recovery. In conclusion, our results suggest that when the tumor is localized, total resection results in a good outcome. However, in the presence of extensive intraabdominal diseases instead of resection, the operation should be limited to biopsy only.     

Effects of gamma-hydroxybutyrate on cerebrospinal fluid lactate and glucose levels after spinal cord trauma.

This study aims to evaluate the effects of gamma-hydroxybutyrate (GHB) after spinal cord trauma (SCT). Twenty rabbits were divided equally into four groups: group I was the sham-operated group, group II suffered from SCT but received no treatment, group III was given a dose of 400 mg/kg of GHB intravenously before SCT and group IV received the same dose after SCT. Cerebrospinal fluid (CSF) samples were obtained 30 min before SCT (T(0)), at 60 (T(1)) and 120 min (T(2)) after SCT. There was a threefold increase in lactate levels from baseline value at T(2) in group II, while statistically significant elevation of the lactate levels were not observed in groups III and IV. Glucose levels at T(1) and T(2) were significantly lower in groups III and IV compared with the control group. The findings of this study demonstrate that GHB can control the increase of CSF lactate and glucose levels following SCT and that this metabolic effect may be associated with neuroprotective physiological changes.     

Allicin inhibits SDF-1alpha-induced T cell interactions with fibronectin and endothelial cells by down-regulating cytoskeleton rearrangement, Pyk-2 phosphorylation and VLA-4 expression

Allicin, a major ingredient of fresh garlic extract that is produced during the crushing of garlic cloves, exerts various beneficial biological effects, including a broad spectrum of antimicrobial activity, antihyperlipidaemic and antihypertensive effects. However, how allicin affects the immune system is less well known, and its effect on human T cells has never been studied. Here, we examined the in-vitro effects of allicin on the functioning of T cells related to their entry to inflamed extravascular sites. We found that allicin (20-100 microm) inhibits the SDF-1alpha (CXCL12)-induced T cell migration through fibronectin (FN), and that this inhibition is mediated by the down-regulation of (i) the reorganization of cortical actin and the subsequent T cell polarization, and (ii) T cell adhesion to FN. Moreover, allicin also inhibited T cell adhesion to endothelial cells and transendothelial migration. The mechanisms underlying these inhibitory effects of allicin are associated with its ability to down-regulate the phosphorylation of Pyk2, an intracellular member of the focal adhesion kinases, and to reduce the expression of the VCAM-1- and FN-specific alpha4beta1-integrin (VLA-4). The ability of allicin to down-regulate these chemokine-induced and VLA-4-mediated T cell functions explains its beneficial biological effects in processes where T cells play an important role and suggests that allicin may be used therapeutically with chronic inflammatory diseases.     

Inhibition of CD4+ T lymphocyte binding to fibronectin and immune-cell accumulation in inflammatory sites by non-peptidic mimetics of Arg-Gly-Asp.

The Arg-Gly-Asp (RGD) cell adhesion motif has been demonstrated in various studies to play a pivotal role in leucocyte and platelet interactions with plasma and extracellular matrix (ECM) glycoproteins. The recognition of the RGD sequence is mediated by heterodimeric receptors designated integrins of the beta 1 subfamily, expressed on distinct cell types, including T lymphocytes. We have recently shown that flexible non-peptidic mimetics of RGD, in which the two ionic side groups were separated by a linear spacer of 11 atoms, bound specifically to the platelet integrin alpha 11b beta 3, and inhibited T cell-mediated immune responses. The present study was designed to (i) further characterize the structural requirements for RGD interactions with CD4+ T cells, and (ii) examine the mechanisms by which the RGD mimetics interfere with immune cell reactivity in vivo. We now report that freezing the conformational degrees of freedom in the spacer chain, which fixes the relative orientation of the guanidinium and carboxylate side groups in a favourable manner, results in a higher level of inhibition of T cell binding to immobilized fibronectin, an RGD-containing ECM glycoprotein. In vivo, treatment of mice with relatively low doses of the RGD mimetics, but not the RGD peptide, inhibited the elicitation of an adoptively transferred DTH reaction. This inhibition was achieved by direct impairment of the ability of antigen-primed lymph node cells to migrate and accumulate in inflammatory sites. Hence, we suggest that the design and production of non-peptidic mimetics of RGD offers a novel approach to study defined parameters related to the structure-function requirements of small adhesion epitopes. Furthermore, this approach could be used therapeutically to inhibit pathological processes which depend on RGD recognition.     

Antibiotic prophylaxis influences cardiovascular stability in complicated surgery

Objective:Antibiotic prophylaxis is used in many surgical procedures but there are frequent cardiovascular instabilities following antibiotics in perioperative period. A clinic modelling randomised trial (CMRT) in pigs was developed to compare the effects of 2 commonly used antibiotic combinations on cardiovascular stability during major surgery. Materials and methods:Thirty pigs (both sexes) were randomised into 3 groups, receiving either saline (placebo), co-amoxiclav or cefuroxime/metronidazole in clinically relevant doses as antibiotic prophylaxis. A laparotomy was performed and the abdomen remained open. Surgical complications were simulated by removing one third of the blood volume. For fluid resuscitation, 500 ml hetastarch (HAES^TM) were infused rapidly (therapy of complication) and polymyxin B (15 mg/kg bodyweight) was applied for induction of histamine release reactions (complication of therapy). The main end points were histamine release reactions, these were classified by 2 blinded investigators. Results:Neither cardiovascular changes nor histamine release reactions were detected immediately after the administration of antibiotics or placebo alone. Plasma histamine concentrations increased after bleeding in the co-amoxiclav group (p < 0.05). After fluid resuscitation and induction of anaphylactoid reactions, the median histamine release and cardiovascular changes were not significantly different between the groups. However, the incidence of typical histamine release related reactions differed significantly between the groups: 8/10 for the controls, 6/10 in the co-amoxiclav and 2/10 in the cefuroxime/metronidazole group (p < 0.05). Conclusions:The stability and reproducibility of this model clearly demonstrated the concept of a ‘clinic modelling randomised trial’ as a useful tool. Antibiotic prophylaxis influences the organism’s capability to cope with intraoperative bleeding and fluid resuscitation problems. Indeed antibiotic prophylaxis may be beneficial. These effects of antibiotics could only be demonstrated in complex surgical models. Thus new antibiotics should be investigated in complex animal models prior to prospective randomised clinical trials or usage in clinical practice.     

Glomerular changes in BK virus nephropathy

This study seeks to define the glomerular changes that are associated with human BK virus nephropathy (BKVN). It is based on histopathologic review of 124 biopsies showing light-microscopic changes of viral nephropathy. The diagnosis of BKVN was confirmed by immunohistochemistry or by in situ hybridization. Histological lesions were scored by the Banff 97 criteria for renal allograft pathology and were correlated with clinical parameters. Viral cytopathic effect in the parietal Bowman's capsular epithelium was seen in 21/124 (17%) biopsies. Immunohistochemistry showed infection of Bowman's capsular epithelium in an additional 15/124 (12%) biopsies. Crescents were found in 15/124 (12%) samples. Glomerulitis exceeding grade Banff g1 was only occasionally shown (4/124=3% biopsies). Other pathologic lesions documented include mild increase in mesangial matrix in 23% biopsies, aneurysmal dilatation of glomerular capillaries in 28%, ischemic glomerulopathy in 62%, and chronic transplant glomerulopathy graded as mild (cg1) in 62% of biopsies and as moderate (cg2) in 2/124 (1.9%) biopsies. These findings show that infection of the glomerular epithelium cells can occur in a subset of patients with BKVN, most often in biopsies with high viral load in the tubular epithelium. Isolated crescents can occur in BKVN biopsies, but rapidly progressive glomerulonephritis is not observed. Two biopsies showed electron-dense deposits on ultrastructural examination, but a cause and effect relationship to BK virus infection could not be established.