Effect of autologous platelet-rich plasma on distraction osteogenesis in the mandible of rabbits: a morphologic and morphometric approach.

Distraction osteogenesis of the jaw is a common surgical practice in the treatment of pediatric craniofacial deformities. Autologous platelet rich plasma (PRP) has been used to increase the healing potential of bones in humans during distraction osteogenesis. This article aims to study the morphometric and morphologic parameters resulting from the effect of PRP on bone healing after mandibular distraction in rabbits. Right mandibular distraction was performed in 12 rabbits divided equally into 2 groups. PRP and physiological saline were injected, according to a defined protocol, in the callus following distraction of the experimental and control groups respectively. The rabbits were sacrificed after a consolidation period of 45 days and the mandibles were surgically removed. Bone mineral density, radiographic analysis, mechanical properties and histological features of the lengthened bones were assessed using radiographic examination, dual X-ray absorptiometry, biomechanical testing and histology. Results showed that the regenerate bone density, the amount of trabeculation in addition to the bone mineral density and mineral content, as measured by absorptiometry, were better with PRP but not significantly different between groups. Two radiographs revealed a more consistent healing in the experimental mandibles compared with erratic outcomes in corresponding controls. Two of the latter could not be subjected to any mechanical testing because the mandibular parts, connected with fibrous tissue, were separated. Consequently, the biomechanical test depicted greater maximal loads in the experimental group. The histological studies exhibited more ossification and less connective tissue fibers in the experimental group. PRP accelerated healing of mandibles in rabbits following distraction and improved their biomechanical properties. These findings have significant clinical implications on reducing the period of consolidation of the mandibles which may not be immobilized like other bones for long periods of time.

Prevalence of IL-1ß +3954 and IL-1α-889 polymorphisms in the Lebanese population and its association with the severity of adult chronic periodontitis.

Pro-inflammatory cytokines, i.e., IL-1 mediate the inflammatory response and are genetically regulated in periodontal diseases. Strong association was found between the composite genotype allele 2 of IL-1ß+3954 and IL-1α-889 and severe chronic periodontitis. The aim of this study is to determine the prevalence of IL-1ß+3954 and IL-1α-889 polymorphism in a group of Lebanese individuals of homogeneous ethnicity and the possible association between genotype positive individuals and the severity of periodontal disease. One hundred and fifty-seven patients aged 53.29±13.13 years participated in the study. Subjects were classified as follows: 1) healthy subjects with no attachment loss >1mm and no clinical signs of gingival or periodontal inflammation; 2) diseased subjects with mild periodontitis (less than 15‰ of global periodontal bone loss); 3) subjects with moderate periodontitis (less than 4 interproximal sites with bone loss = or >50 percent and mean bone loss between 15 and 30%); 4) subjects with severe periodontitis (more than 7 interproximal sites with >50% bone loss and mean bone loss >35‰). Blood samples were taken and analyzed for polymorphism in the IL-1α gene at position +4845 and in the IL-1beta gene at position +3953. Statistical analysis was performed using chi-square test, Fisher Exact test, and ANOVA followed by Bonferroni multiple comparisons. The prevalence of genotype-positive subjects was 52.3‰ in the healthy control group and 42 ‰ in the diseased group. Positive genotype heterozygous of allele 1 and 2 for IL-1ß+3954 and IL-1α-889 did not represent in this study a major risk for chronic periodontitis (p=0.590). Only subjects homozygous for allele2 of the IL-1ß+3954 and IL-1α-889 were significantly more at risk for severe periodontitis with OR of 51.42.

Human dental pulp cell apoptosis: immunohistochemical study after applying orthodontic traction.

The aim of this study was to compare human dental pulp stress and programmed cell death after 3 and 6 months of orthodontic treatments by assessing the degree of apoptosis and related proteins. Human dental pulps were collected from twenty young patients orthodontically treated by Straight Wire technique. Samples were fixed, paraffin-embedded and processed for histology and immunohistochemistry using anti-heat shock protein 60 kDa (Hsp60), -caspase 3, -caspase 9, and -PCNA antibodies, as well as TUNEL reactions. Moreover, we performed immunoprecipitation for Hsp60 and caspase 3, and for Hsp60 and caspase 9, from paraffin extracted tissues. Increased levels of both caspases and Hsp60 occurred in 6-months treated samples; at the same time, we found increased levels of proliferating cell nuclear antigen and terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells. Immunoprecipitation showed that Hsp60 forms a complex with both Pro-caspase 3 and Caspase 3, and this may accelerate Pro-caspase 3 activation, especially in the 6-months treated group. On the contrary, no complex between Hsp60 and Pro-caspase 9 was detected. The orthodontic tractions may be a cause of stress, apoptosis and proliferation in pulp tissue. These results suggest the need of further studies about the effects of long term orthodontic treatments on the dental pulp.

Rat model of burn wound healing: effect of Botox.

Animal models of burn play a crucial role in studying the mechanisms of burn wound progression and the factors that regulate various stages of healing. In this study, using a rat model, we assessed the effect of Botox in the healing process through parameters like transepidermal water loss (TEWL), histological alterations, transforming growth factor beta (TGF-beta1) and tumor necrosis factor alpha (TNF-alpha). Fifty Sprague-Dawley rats were inflicted with 5 cm2 second degree burn and divided into 2 groups; one group was injected intralesionally with Botox and the other with saline. Daily observation and transepidermal water loss measurement were performed. Biopsies were taken on days 0, 3, 8, 14, and 28 for histology and polymerase chain reaction, testing TGF-beta and TNF-alpha. The results showed no significant difference in TEWL except for slightly better preservation of moisture with Botox. Histology revealed relatively better and faster regeneration with Botox, delayed lower grade inflammation, and increase in fibroblasts. TNF-alpha had an acute increase of 21-fold then tapered down while TGF-beta levels increased on day 3 after TNF-alpha, peaked on day 8 and then started to decrease until complete healing. Botox improved the healing process and the cosmetic appearance of burn scar.

Enteropathogenic e.coli sustains iodoacetamide-induced ulcerative colitis-like colitis in rats: modulation of IL-1ß, IL-6, TNF-α, COX-2, and apoptosisi.

Pathogenic or non-pathogenic bacteria from flora may play a key role in inflammatory bowel disease (IBD) pathogenesis. However, a specific infectious agent causing IBD has not been identified. This study assessed the impact of enteropathogenic E. coli (EPEC) on the modulation of IL-1beta, IL-6, TNF- alpha, COX-2, BAX and Bcl-2 expression, in sustaining inflammation of a rat colitis model. Two hundred male Sprague-Dawley rats (4 groups) were inoculated weekly or bi-weekly for 70 days, with 1 percent methylcellulose (MC), (b) 6 percent iodoacetamide (IA) in 1 percent MC, (c) 4x108 CFU of EPEC, and (d) IA+EPEC. After a month, treatment was stopped in half of the animals in each group. IL-1beta, IL-6, TNF-alpha, COX-2, BAX and Bcl-2 expression were measured in colonic mucosa scrapings. IL-1beta, IL-6, TNF-alpha, and COX-2 were significantly increased in colonic mucosa of the IA+EPEC group and to a lesser but significant level in the IA group compared to controls, or EPEC alone, both in continued and discontinued treatment groups. Additionally, the BAX/Bcl-2 ratio decreased, indicating less apoptosis in the IA+EPEC group which exhibited more necrosis. These effects increased with experiment duration. This work provides new arguments favouring the role of bacteria in IBD pathogenesis.

Cytology and clinical spectrum of sexually transmitted infections in Lebanese women as revealed by Pap smear: a cross-sectional study from 2002-2006.

To study the cytology profile of cervical smears and the respective prevalence and incidence of certain cervico-vaginal infections detectable by routine Pap smear cytology in Lebanese women from 2002 to 2006. Pap smear cytology results were compiled from the archives of the Institut National de Pathologie for the period extending from 2002 until 2006. This study covered 118,230 cervical specimens obtained from Lebanese women attending clinics and hospitals in all the five districts of Lebanon; prevalence and incidence rates for infections detectable by routine Pap smear examination were determined. A rise in prevalence of these infections by 2.1 percent (2,555) from 2002 to 2006 was revealed. A doubling of Pap smears showing HPV-associated changes was detected (1.4 percent in 2002 to 2.9 percent in 2006), and a simultaneous almost 7-fold increase of Atypical Squamous Cells of Undetermined Significance (ASCUS) cytology was detected during this period; the rise in ASCUS cytology was age-dependent. Moreover, a 60 percent increase in prevalence of bacterial vaginosis (2.3 percent in 2002 to 3.7 percent in 2006) and a more than 3-fold decline in Trichomonas vaginalis infection (1 percent in 2002 to 0.3 percent in 2006) were also noted in this population during this period. An increase in the prevalence and incidence of cervico-vaginal infections detectable by Pap smear cytology in Lebanese women was revealed from 2002 to 2006. Such changes could point to recent modifications of sexual and health behaviours in the Lebanese community.