ABSTRACT Computers are increasingly present in operating rooms, dental examination rooms, Intensive care unit and wards for bedside documentation. Recently they have been suspected as possible reservoirs for mi- croorganisms and provide opportunities for the transfer of pathogens to patients and ultimately leading to cause no- socomial infections. A number of studies indicate that healthcare workers may contaminate their hands by touching contaminated environmental surfaces and that contaminated hands participate to transmit the pathogen to patients. Pathogens may also be transferred directly from contaminated environmental surfaces to susceptible host in health care setting. The purpose of this study was to examine the microbial contamination of computer keyboards with potentially patho- genic microorganisms in clinical area and to postulate that computer keyboards are significant reservoirs of nosocomial pathogen. Sterile swab samples were received from 20 computer keyboards randomly from fifth year medical and fourth year dental students at AlJabal AlGharbi University and Gharian teaching hospital during a period of one month. These computer keyboards were used in clinical areas (in hospital sitting or dental practice unit). Microbes obtained from the specimens were identified to the species level on the basis of colony morphology, gram stain, biochemical test and API. Organisms isolated from the keyboards included Micrococci, Bacillus spp, Coagulase-negative staphylococci and less common isolates were Staph. aureus, Bacteroides, Flavobacterium spp, Listeria grayi, and Pseudomonas spp. Some keyboards were also contaminated with anaerobic environmental organisms. The findings of this study add evidence to support the hypothesis that these particular surfaces may serve as reservoirs of nosocomial pathogens and vector for cross transmission of infection in universities and hospital setting.

. Comparative analyses of the sequencesof DNA repair gene (Hex A) between different strains of Streptococcus pneumoniae

Abstract: Objective: The present study has been designed to evaluate the histological effects of the daily consumption of omega-3 on submandibular salivary gland of old rats. Material & methods: Forty old white male rats (12-15 month age old), weighing 300 to 350gs, were used in this study. The rats were divided into two groups (20 rats/each). Control group where rats did not receive any dietary supplement. Experimental group where rats received omega-3 (60 mg/Kg) twice daily for three months through intra- gastric intubation. All rats were sacrificed after three months. Soft tissue specimens were obtained from submandibular salivary gland of the rats in all the studied groups. The sections were examined histologically and ultra-structurally. Results: Histopathological changes observed in control group included; distortion and decrease in the overall size of the acini and granular convoluted tubules increase in the amount of fatty tissue, fibrous tissue and inflammatory cell infiltration. In experimental group, the acini and ducts appeared nearly normal and there was marked decrease in the inflammatory cell infiltration. Electron microscopic examination of the control group revealed cytoplasmic vacuolization in acini and ducts, degenerated organelles and pyknotic nuclei. In experimental group, the acini and ducts appeared nearly normal in size, shape and structure. Conclusion: Omega-3 showed significant improvement in many age related changes of submandibular salivary gland.الملخص: الهدف: صممت الدراسة الحالية لتقييم التأثيرات النسيجية لليوم استهلاك أوميغا 3 على الغدد اللعابية تحت الفك السفلي للفئران القديمة. المواد والطرق: أربعون ذكرا أبيض يبلغ من العمر تم استخدام الفئران (12-15 شهرا) ، التي تزن 300 إلى 350 جراما ، في هذه الدراسة. تم تقسيم الفئران إلى مجموعتين (20 جرأ / لكل منهما). المجموعة الضابطة حيث لم تتلق الفئران أي مكمل غذائي. المجموعة التجريبية حيث الفئران تلقى أوميغا 3 (60 مجم / كجم) مرتين يوميا لمدة ثلاثة أشهر من خلال التنبيب داخل المعدة. تم التضحية بجميع الفئران بعد ثلاثة أشهر. تم الحصول على عينات الأنسجة الرخوة من الغدة اللعابية تحت الفك السفلي للفئران في جميع المجموعات المدروسة. تم فحص الأقسام من الناحية النسيجية والهيكلية الفائقة. النتائج: نسيجية مرضية وشملت التغييرات التي لوحظت في المجموعة الضابطة; تشويه وانخفاض في الحجم الكلي للأسيني والحبيبات تزداد الأنابيب الملتوية في كمية الأنسجة الدهنية والأنسجة الليفية وتسلل الخلايا الالتهابية. في المجموعة التجريبية ، بدت الأسيني والقنوات طبيعية تقريبا وكان هناك انخفاض ملحوظ في الالتهابات تسلل الخلايا. كشف الفحص المجهري الإلكتروني للمجموعة الضابطة عن تفريغ السيتوبلازمي في أسيني والقنوات والعضيات المتدهورة والنوى pyknotic. في المجموعة التجريبية ، ظهرت الأسيني والقنوات تقريبا طبيعي في الحجم والشكل والهيكل. الخلاصة: أظهرت أوميغا 3 تحسنا كبيرا في العديد من الأمراض المرتبطة بالعمر تغيرات الغدة اللعابية تحت الفك السفلي.

Abstract:

Aim of the study: The purpose of current study was to evaluate and compare the effect of different connector designs on the 

compressive strength of posterior inlay-retained fixed dental prostheses made from two different ceramic systems.

Materials and Methods: Twenty-eight inlay retained fixed partial denture (IRFPDs) were used to replace missing lower right first 

molar. According to the IRFPDs material (lithium disilicate ceramic and Zirconia), the specimens were divided into two main groups A 

and B (n=14). These groups were further subdivided into 2 sub-groups 1&2 (n=7) according to the connector designs used (round and 

sharp). The IRFPDs were manufactured using the hot press and CAD-CAM techniques respectively. All specimens were cemented using 

self-adhesive resin cement. Each specimen was placed on the test device, and compressive force was applied till the failure occurred. All 

the results obtained were statistically analyzed by two way ANOVA test and student t test (level of significance p < 0.05). 

Results: Revealed that the highest mean value of compressive strength was for round connector with zirconia IRFPDs. While the lowest 

value was for sharp connector with lithium disilicate IRFPDs.

Conclusions: Within the limitations of this in-Vitro study the following conclusion could be obtained; zirconia demonstrated high 

compressive strength than lithium disilicate. Despite the lithium disilicate possessed the lowest compressive strength values for both 

types of connector design. However these values were greater than the average occlusal force recorded in several studies.

Keywords: IRFPDs, Connector design, Fixed prosthesis, CAD/CAM, Zircoina, Lithium disilicate, Compressive strength.

 Interleukin-10 (IL-10) is an anti-inflammatory cytokine that has been shown to play a role in inflammatory and autoimmune disorders as well as in neuropathic pain conditions.

The objective of the present study was to assess the levels of IL-10 in rat’s dorsal root ganglion (DRG) and the sciatic nerve following four different forms of sciatic nerve injury. The models used to induce the injury included two models of partial nerve injury: partial sciatic ligation (PSL) and chronic constriction injury (CCI), a model of complete sciatic transection (CST) and a model of perineural inflammation with minimal nerve damage (neuritis). Withdrawal responses for mechanical stimulus and withdrawal latency for thermal stimulation were used to measure mechanical and thermal hyperalgesia, respectively, and duration of the nociceptive withdrawal reflex to mechanical stimulus was used to measure mechanical hyperalgesia.

The affected and contra-lateral nerves and the affected side DRG IL-10 levels were assessed by the means of enzyme-linked immunosorbent assay (ELISA), 3 and 8 days following the procedure and were compared to naïve rats’ IL-10 levels.

The rats exposed to CCI and neuritis developed significant mechanical and thermal hyperalgesia as well as mechanical hyperalgesia 3 and 8 days following the surgical procedure. Rats exposed to CST did not respond to mechanical stimulation and developed thermal hypoalgesia 3 and 8 days after the surgery.

The DRG IL-10 levels were significantly reduced 3 and 8 days following CCI and PSL, significantly increased 3 and 8 days following CST, and remained unchanged following neuritis.

The sciatic nerve IL-10 levels reduced significantly in both injured and contra-lateral nerves 3 and 8 days following CCI and PSL, elevated significantly in the injured but not in the contra-lateral nerve 3 and 8 days following CST and remained unchanged following neuritis. The results of this study suggest that IL-10’s role in the neuropathic pain etiology may be specific to nerve injury type.

Complete nerve transection increases while partial nerve injury reduces IL-10 levels in the involved nerve, and DRG. Perineural inflammation with minimal nerve damage has no effect on IL-10 levels.

ABSTRACT Introduction: Salivary gland tumors (SGTs) may represent a considerable diagnostic challenge, primarily because of the complexity of the classification and the rarity of several entities. Since proliferative activity is a reliable method to assess tumor biology. There has been continuous research to find such biological markers. Ki-67 is a widely accepted proliferation marker, with its expression tightly associated with the cell cycle. It is implicated in many of human cancers as a prognostic factor. MCM-3, member of minichromosome maintenance proteins family, is upregulated in proliferating cells. MCM-3 overexpression in almost all human cancers implicates that it might facilitate the tumorigenesis by playing a role in the malignant transformation of cells. Objectives: to evaluate the MCM-3 protein expression in benign and malignant salivary gland tumors and compare the obtained results with the expression of Ki-67 proliferation antigen. Materials and methods: Immunohistochemical analysis of 20 cases of SGTs with 2 sections from each specimen (20 sections for antiKi67antibody and 20 sections for antiMCM3antibody) and 5 control cases. Immunohistochemical staining was performed using a Labeled StreptAvidin Biotin method (LSAB). Results: Normal salivary gland tissue showed negative immunoreactivity for both Ki-67 and MCM-3 in epithelial and myoepithelial cells. All the examined cases showed positive expression for both proliferative markers in benign and malignant SGTs, with different intensities. Conclusions: The proliferative markers Ki-67 and MCM-3 proteins are overexpressed in malignant salivary gland tumors, than benign ones. Both Ki-67 and MCM-3 may be reliably applied as diagnostic markers to distinguish benign from malignant salivary gland tumors. Keywords: Salivary gland tumor, Immunohistochemistry, MCM-3, KI-67.

Circulating microvesicles (cMVs) are the extracellular MVs released from the cells in the blood and on the vascular wall. Our previous study demonstrates that cMVs of diabetic mouse are detrimental to endothelial progenitor cells (EPCs), which are known to be very important for maintaining normal endothelial function and structure. In this study, we compared the levels of circulating EPCs and EPC-derived MVs (EPC-MVs) in diabetic and healthy subjects. Also, the migration ability, apoptosis rate and reactive oxygen species (ROS) production of EPCs cultured from diabetic and healthy subjects were determined. More importantly, we evaluated whether cMVs from healthy subjects (ch-MVs) improves the function of EPCs from diabetic patients (d-EPCs), and whether cMVs from diabetic patients (cd-MVs) impairs the function of EPCs from healthy subjects (h-EPCs). The d-EPCs or h-EPCs were incubated with ch-MVs or cd-MVs for 24 hours. The migration ability of EPCs was analyzed by an assay kit. The apoptotic rate and ROS production were analyzed by labeling with propidium iodide (PI) and dihydroethidium (DHE) respectively, followed with flow cytometeric analysis. Our data showed that (1) there was a decrease in EPCs iv and an elevation in EPC-MVs in diabetic patients when compared to healthy subjects; (2) The migration ability of d-EPCs were decreased, and the apoptosis rate and ROS production were increased in d-EPCs; (3) ch-MVs improve the function of d-EPC through improving its migration ability and decreasing the apoptosis and ROS production; (4) cd-MVs increase h-EPC apoptosis, and increase ROS production. We conclude that cMVs modulate EPC function and this role of cMVs is reversed in diabetes with the mechanism linked to ROS production.