Qualitative and quantitative evaluation of avian demineralized bone matrix in heterotopic beds.

OBJECTIVE: To evaluate the osteogenic potential of avian demineralized bone matrix (DBM) in the context of implant geometry. STUDY DESIGN: Experimental. ANIMALS: Rock pigeons (n = 24). METHODS: Tubular and chipped forms of DBM were prepared by acid demineralization of long bones from healthy allogeneic donors and implanted bilaterally into the pectoral region of 24 pigeons. After euthanasia at 1, 4, 6, 8, 10, and 12 weeks, explants were evaluated histologically and compared by means of quantitative (bone area) and semi quantitative measures (scores). RESULTS: All explants had new bone at retrieval with the exception of tubular implants at the end of week 1. The most reactive part in both implants was the interior region between the periosteal and endosteal surfaces followed by the area at the implant-muscle interface. Quantitative measurements demonstrated a significantly (P = .012) greater percentage of new bone formation induced by tubular implants (80.28 ± 8.94) compared with chip implants (57.64 ± 3.12). There was minimal inflammation. CONCLUSIONS: Avian DBM initiates heterotopic bone formation in allogeneic recipients with low grades of immunogenicity. Implant geometry affects this phenomenon as osteoconduction appeared to augment the magnitude of the effects in larger tubular implants.

Heterotopic implantation of autologous bone marrow in rock pigeons (Columba livia): possible applications in avian bone grafting.

Autologous bone marrow, alone or as a composite marrow graft, has received much attention in various species. To assess the potential osteogenicity of autologous, extramedullary bone marrow implants in an avian model, 24 adult pigeons (Columba livia) were given intramuscular implantations of autologous marrow aspirated from the medial tibiotarsus. Birds were euthanatized at 1, 4, 6, 8, 10, and 12 weeks after surgery to evaluate whether ectopic bone had formed at the implant sites. Primary evaluations by in situ radiography and postmortem histologic examinations showed no evidence of bone formation. Further evaluation with histologic scores and histomorphometry revealed a significantly increased rate of angiogenesis at the implant sites by the sixth and tenth week postimplantation (P < .05). No significant differences between the treatment and control sites were present at any other endpoints. Results of this study show that, although autologous bone marrow lacks heterotopic osteogenic potentials in this avian model, it could still function as a useful adjunct to routine bone grafting techniques because of its unique capabilities to promote early angiogenesis.

Sentinel hospital-based surveillance of rotavirus diarrhea in iran.

BACKGROUND: Rotavirus is the most common causes of severe, acute diarrhea during childhood and is an important cause of morbidity and mortality in developing countries. We established active hospital-based surveillance of childhood diarrhea to assess the scope of severe rotavirus disease in Iran. METHODS: From May 2006 through April 2007, prospective surveillance of rotavirus diarrhea among children aged <5 years was conducted in 5 sentinel hospitals in Iran. Stool samples were tested for rotavirus using a commercially available enzyme immunoassay, and rotavirus-positive samples were genotyped using reverse-transcriptase polymerase chain reaction. RESULTS: Of 2198 children admitted to the hospital for acute gastroenteritis, 1298 (59.1%) had stool samples test positive for rotavirus by enzyme immunoassay. Of the rotavirus episodes, 85% occurred during the first 2 years of life, with the peak prevalence of severe rotavirus disease occurring from September through January. Among the 110 rotavirus-positive samples that were genotyped, G4P[8] was the most commonly detected rotavirus genotype (30.9% of strains). Other commonly detected genotypes included P[8] with G nontypeable (21.8%), G4 with P nontypeable (13.6%), G1[P8] (10.9%), and G2[P4] (5.5%). CONCLUSIONS: Rotavirus is the most common cause of severe diarrhea in Iran, which indicates that safe and effective rotavirus vaccination in Iran is a public health priority.

Effect of valproic acid and zebularine on SOCS-1 and SOCS-3 gene expression in colon carcinoma SW48 cell line.

BACKGROUND: Two epigenetic modifications such as histone acetylation and DNA methylation have been known as critical players of gene regulation. Hypermethylation and deacetylation of suppressors of cytokine signaling family SOCS-1 and SOCS-3 have been shown in many solid cancers. Previously, we evaluated the effect of 5-aza-2'-deoxycytidine and valproic acid on hepatocellular carcinoma and colon cancer cells. AIM: The present study was designed to assess the effect of valproic acid in comparison to zebularine on SOCS-1 and SOCS-3 gene expression, cell growth inhibition and apoptosis induction in colon carcinoma SW48 cell line. MATERIALS AND METHODS: SW48 cells were treated with valproic acid or zebularine for 24 h and 48 h. The effect of the compounds on cell viability, SOCS-1 and SOCS-3 gene expression, and apoptosis induction was evaluated. Reverse transcription polymerase chain reaction analysis and flow cytometry were applied. RESULTS: Both agents inhibited cell growth in a time- and dose-dependent fashion. The apoptotic effect was observed in cells treated with valproic acid (7.5 µM) but not zebularine (75 µM). The valproic acid but not zebularine upregulated SOCS-1 and SOCS-3 gene expression. CONCLUSION: Epigenetic modulation can reactivate silenced tumor suppressor genes SOCS-1 and SOCS-3 through histone acetylation resulting in apoptosis induction.

Effect of valproic acid in comparison with vorinostat on cell growth inhibition and apoptosis induction in the human colon cancer SW48 cells in vitro.

AIM: Acetylation levels of histones are the result of the balance between histone acetyltransfrases and histone deacetylases activities, which plays an important role in chromatin remodeling and regulation of gene expression. Histone deacetylases inhibitors such as valproic acid, vorinostat have attracted interest because of their ability to induce differentiation and apoptosis of cancer cells. The current study was designed to assess the effect of valproic acid in comparison to and in combination with vorinostat on cell growth inhibition and apoptosis induction in the human colon cancer SW48 cells. MATERIALS AND METHODS: The colon cancer SW48 cells were seeded and treated with various doses of valproic acid and vorinostat and MTT assay and flow cytometric assay were done to determine cell viability and cell apoptosis, respectively. RESULTS: All concentrations of both agents reduced viability significantly in a dose- and time-dependent fashion (p < 0.004). Both compounds, either single or combined agents, induced apoptosis significantly, whereas the ratio of the apoptotic cells treated with combined agents was more significant than the single. CONCLUSION: Our findings suggest that vaproic acid and vorinostat can significantly inhibit cell growth and induce apoptosis in colon cancer SW48 cells.