How safe is the use of prosthetic materials in the repair of abdominal-wall defects in malnourished subjects?

Incisional hernias and abdominal-wall defects consume large amounts of healthcare resources. Use of mesh is effective in treatment of these disorders and can decrease the rate of recurrence. This experimental study focused on the safety of mesh use in the setting of malnutrition, a condition that impairs wound healing. Rats were divided into two groups: normally fed and food-restricted. An abdominal-wall defect, 2 by 2 cm, was covered with polypropylene mesh, 2.5 by 2.5 cm. After sacrifice of the rats at the 21st and 60th days, tissue samples were sent for tensiometric and histopathological studies. No significant difference in infectious complications was observed between the two groups. Tensiometry revealed no significant differences between the groups. On histopathological examination, the only difference noted was in the vascularization scores of normally fed rats. For malnourished subjects that survived after surgery, the use of polypropylene mesh appeared safe in the closure of abdominal-wall defects, with no increase in infection rate and satisfactory wound healing.     

Granulocyte colony-stimulating factor enhances bone tumor growth in mice in an osteoclast-dependent manner

Inhibition of osteoclast (OC) activity has been associated with decreased tumor growth in bone in animal models. Increased recognition of factors that promote osteoclastic bone resorption in cancer patients led us to investigate whether increased OC activation could enhance tumor growth in bone. Granulocyte colony-stimulating factor (G-CSF) is used to treat chemotherapy-induced neutropenia, but is also associated with increased markers of OC activity and decreased bone mineral density (BMD). We used G-CSF as a tool to investigate the impact of increased OC activity on tumor growth in 2 murine osteolytic tumor models. An 8-day course of G-CSF alone (without chemotherapy) significantly decreased BMD and increased OC perimeter along bone in mice. Mice administered G-CSF alone demonstrated significantly increased tumor growth in bone as quantitated by in vivo bioluminescence imaging and histologic bone marrow tumor analysis. Short-term administration of AMD3100, a CXCR4 inhibitor that mobilizes neutrophils with little effect on bone resorption, did not lead to increased tumor burden. However, OC-defective osteoprotegerin transgenic (OPG(Tg)) mice and bisphosphonate-treated mice were resistant to the effects of G-CSF administration upon bone tumor growth. These data demonstrate a G-CSF-induced stimulation of tumor growth in bone that is OC dependent.     

Heme oxygenase-1 deficiency as an extremely rare cause of AA-type renal amyloidosis: Expanding the clinical features and review of the literature

Clinical Rheumatology - Heme oxygenase-1 (HMOX-1) is an enzyme that regulates heme degradation. Antiinflammatory, antioxidant, and cytoprotective effects of HMOX-1 were also described. It is...     

Mechanism of relaxation induced by nicotine in normal and ovalbumin-sensitized guinea-pig trachea

Nicotine is an irritant molecule in the cigarette that contributes airway hyper-reactivity. The aim of this study was to investigate the mechanism of these effects and effects of nicotine on the isolated trachea preparations from control and ovalbumin-sensitized guinea-pigs. Nicotine (3x10(-5) to 3x10(-4) M) produced concentration-dependent relaxation on isolated trachea preparations precontracted by carbachol (10(-6) M) in both groups. We found that the relaxant effect of nicotine decreased in the presence of N(w)-nitro L-arginine methyl ester (L-NAME) (10(-6) M), and hexamethonium (10(-2) M) but not in the presence of alpha-bungarotoxin (10(-3) M), and tetrodotoxin (3.1x10(-6) M) in isolated trachea preparations in both groups. The relaxant effect of nicotine was less significant in isolated trachea preparations from ovalbumin-sensitized guinea-pigs than from control guinea-pigs (P<0.05). The contractions elicited by carbachol (10(-6) M) were not significantly different in the ovalbumin-sensitized group than in the control group. Nicotine (10(-4) M) significantly increased the cGMP levels in trachea preparations compared with the control preparations.(P<0.05). These results suggest that nicotine-induced relaxation response in normal and ovalbumin sensitized guinea-pigs trachea is at least in part mediated by nitric oxide (NO) since it was significantly reduced in the presence of L-NAME. The decreased relaxation response to nicotine in ovalbumin sensitized guinea-pigs trachea may be due to impaired production and/or liberation of NO.     

The distribution of the Phlebotomus major complex (Diptera: Psychodidae) in Turkey

The taxonomic status and distribution of the morphologically similar members of the Phlebotomus major complex in Turkey are unclear. To examine the utility of traditional morphological characters and molecular markers, sand flies were sampled from 90 localities in eleven different provinces covering a wide geographical range throughout Turkey. The morphometric variability was analysed using multivariate analyses of twelve characters, while mitochondrial cytochrome b (Cyt b) and nuclear elongation factor 1α (EF 1-α) genes were used for molecular discrimination. Three distinct monophyletic lineages were identified based on the phylogenetic analysis of the combined data set of mitochondrial and nuclear gene regions, which were also supported by parsimony haplotype network analysis and AMOVA of Cyt b. The first lineage is restricted to south eastern Turkey and represents the species Phlebotomus syriacus, the second is present mostly in the westernmost and the easternmost localities and represents P. neglectus, and the third member of this complex is distributed across the mid-northern and mid-southern regions. None of the studied morphological characters were found to be sufficient to discriminate between these three members of the P. major s.l. complex; however their presence sympatrically in several localities supports their status as species rather than inter-population variability.