Mohammed E. Grawish

Effects of Spirulina platensis extract on Syrian hamster cheek pouch mucosa painted with 7,12-dimethylbenz[a]anthracene.

Research into cancer prevention seeks to identify the preventable causes of cancer, and to reduce cancer incidence by effective implementation of preventative strategies in target populations. In this study, 30 male golden Syrian hamsters were divided into three equal groups; the right buccal pouches of the hamster rats in group one were painted with 0.5% solution of 7,12-dimethylbenz[a]anthracene (DMBA), three times a week, until sacrificed. The same pouches of group two were also painted with DMBA, but received an additional 10mg/daily Spirulina platensis extract, which was added to the soft diet supplements during the same period. The hamster rats in group three received neither DMBA nor S. platensis extract. They were painted with saline and served as control animals. Half the hamsters from each of the three groups were sacrificed by ether inhalation after 7 weeks, and the remaining half were sacrificed after 14 weeks. The required buccal pouches were surgically excised and prepared for regular H&E and argyrophilic proteins of the nuclear organizer regions (AgNOR) silver staining. AgNORs counting and statistical analysis were carried out. We observed moderate dysplastic changes extending into the midspinous layer in group one 7 weeks after DMBA painting, which reached to half the thickness of the hyperplastic epithelium after 14 weeks. However, in group two, mild dysplastic changes were observed after 7 weeks, which were restricted to the basilar and parabasilar layers of the epithelium after 14 weeks of treatment. AgNOR staining in group one produced AgNOR counts ranging from one to seven dots per nucleus, whereas the counts were one or two dots per nucleus in group two. The AgNOR mean number in groups one, two and three was (3.1+/-0.006, 1.3+/-0.003 and 1.2+/-0.003, respectively). Moreover, with one sample t-test, a significant difference was found in AgNOR mean number between groups one and two, groups one and three and between groups two and three (P<0.05). An overall significant difference among the three groups (P<0.01) was indicated with one-way analysis of variance. The pAgNOR was 10% in group one, 5% in group two and 4% in group three. Consequently, S. platensis is an adjunctive means to inhibit the dysplastic changes occurring in the hamster cheek pouch (HCP) mucosa. However, more research is needed to expand its beneficial action.

Predictive value of cyclooxygenase 2 and Bcl-2 for cervical lymph node metastasis in mucoepidermoid carcinoma

The expression of cyclooxygenase 2 (COX-2) is induced by growth factors, tumor promoters, and cytokines. It is correlated with carcinogenesis and apoptosis inhibition. This study was designed to investigate the expression of COX-2 and BCl-2 and to correlate their expressions with the clinicopathologic features in the mucoepidermoid carcinoma (MEC). The expression of COX-2 and BCl-2 proteins was investigated in 16 archival tumor tissues of MEC using the streptavidin-biotin complex technique. Clinical information was obtained through the computerized retrospective database from the tumor registry between 2001 and 2007. It revealed that grading system of MEC did not correlate with the presence or absence of node metastasis. The expression of COX-2 and BCl-2 was variably expressed in all the examined specimens. COX-2 and BCl-2 immunoreactivity was observed mainly in the cytoplasm of neoplastic cells. As regard the clinicopathologic parameters, there was no significant difference in expression rates of COX-2 in patients among age, sex, and MEC grades (P > .05). However, the expression of COX-2 in node-positive tumors was significantly higher than that of node-negative tumors (P = .001). For BCL-2 expression, there was no significant difference in expression rates of BCl-2 in patients among age, sex, site, clinical stage, and lymph node metastasis (P > .05), whereas a high significant difference was observed between BCl-2 staining index and MEC grades (P = .027). Moreover, there is a positive correlation between COX-2 expression and BCL-2 staining index (P = .000). COX-2 is a good predictor for lymph node metastasis as well as ideal therapeutic target for the prevention or treatment of MEC. BCl-2 and COX-2 are potentially useful prognostic markers for MEC.

Influence of selective immunosuppressive drugs on the healing of exposed dogs' dental pulp capped with mineral trioxide aggregate.

INTRODUCTION Immunosuppressive drugs are used in clinical medicine for a variety of disorders, but their effects on the reparative capacity of the dental pulp are unknown. This study evaluated the influence of selected immunosuppressive drugs on pulpal tissue healing after direct pulp capping of mechanically exposed dogs teeth with mineral trioxide aggregate (MTA). METHODS Ten healthy male dogs were assigned into 5 experimental groups: a control group in which no drug was received and 4 experimental groups in which the immunosuppressive drugs prednisone, mycophenolate mofetil, sirolimus, and cyclosporine A were administered 45 days before the operative procedures and until the dogs were killed. Class V cavities were prepared on the buccal surfaces of 12 teeth in each dog. In each cavity, the pulp was exposed and capped with MTA. The pulpal tissue responses to capping material were assessed 65 days postoperatively. RESULTS Compared with the control group, variable responses was recorded in the groups treated with mycophenolate mofetil, sirolimus, and cyclosporine A, which were characterized by moderate to severe inflammatory reactions, tissue necrosis, and total absence of hard tissue bridging. Pulpal tissue responses in the group treated with prednisone were characterized by inflammatory cell infiltration, limited tissue necrosis, as well as partial to complete hard tissue bridging. CONCLUSIONS From these findings, it seemed evident that acceptable repair of the dentin-pulp complex, eg, wound healing with hard tissue formation after capping with MTA, is unlikely with mycophenolate mofetil, sirolimus, or cyclosporine A immunosuppressive drug therapy.

Impact of three different mouthwashes on the incidence of gingival overgrowth induced by cyclosporine-A: a randomized controlled experimental animal study

OBJECTIVE This study aimed to evaluate the effects of three different mouthwashes on the incidence of cyclosporine-A-induced gingival overgrowth. STUDY DESIGN One hundred albino rats were divided into five equal groups. Group I rats received no treatment. Group II rats were administered cyclosporine-A. Group III, IV, and V rats were handled as group II and concomitantly treated with chlorhexidine gluconate, cetylpyridinium chloride, and essential oil mouthwashes, respectively. Ten rats from each group were euthanized after the first week of treatment, and the remaining rats were euthanized after the second week of treatment. The obtained specimens were stained with hematoxylin and eosin, Massons trichrome, and tumor growth factor beta (TGF-β), matrix metalloproteinase 1 (MMP-1), and interleukin 6 (IL-6) immunohistochemical stains. RESULTS The histologic findings at the end of the first and second weeks revealed marked increases in gingival overgrowth for groups II and IV in comparison with groups III and V. Increased epithelial thickness and collagen accumulation were prominent in groups II and IV compared with the other groups. Groups II and IV revealed the highest immunoreactivities for TGF-β and for IL-6. Groups I, III, and V revealed the highest level of MMP-1 expression. CONCLUSIONS Essential oils and chlorhexidine gluconate mouthwashes significantly reduced the incidence of gingival overgrowth compared with cetylpyridinium chloride.

Vasculitis of Dental Pulp Associated with Cryoglobulinemia in Hepatitis C Virus Patients: Case Report

INTRODUCTION This report presents a case of impacted lower third molar extracted for surgical reasons in patient with uncontrolled hepatitis C. After decalcification, dental pulp vasculature and its tissue quality were investigated. METHODS Serial sections of 4-μm thickness along the midline buccolingually for the demineralized specimen were obtained, mounted on a glass slide, stained with hematoxylin-eosin, covered, and viewed under the light microscope. RESULTS The histologic investigation of the pulp tissue revealed thickening, stenosis, and occlusion of the vessel wall, ectopic calcification of the pulp tissue in close association with pulpal blood vessels, interrupted and vacuolated odontoblastic layer in the coronal pulp chamber, with an inflammatory cell infiltrate throughout the pulpal tissue. CONCLUSIONS Cryoglobulinemia associated with uncontrolled hepatitis C virus infection in patients endangers the dental pulp vasculature and alters its normal tissue architecture.

Regenerative capacity of allogenic gingival margin- derived stem cells with fibrin glue on albino rats’ partially dissected submandibular salivary glands

OBJECTIVE To evaluate the possible regenerative effect of allogenic gingival margin-derived stem cells (GMSCs) with or without autologous fibrin glue on partially dissected submandibular salivary glands of albino rats. METHODS Forty rats were randomly divided into four equal groups. Group I, where no operation was performed, was considered the negative control. Group II rats were considered the positive control and were subjected to a rectangular cut on the outer surface of the center right of the submandibular salivary gland and received no other treatment. Groups III and IV rats were handled as those in group II, but the cut areas of group III were filled with fibrin glue and the cut borders of group IV were injected with 1×105cell/ml GMSCs and then glued with fibrin glue. Five animals from each group were euthanized at the end of the first postoperative week, while the remaining animals were euthanized at the end of the second postoperative week, i.e., end of the experiment. RESULTS Regeneration of ductal, acinar, and myoepithelial cells was better in group IV. A two-way ANOVA for proliferating cell nuclear antigen and α-smooth muscle actin revealed an overall significant difference between the different groups (P<0.05). In addition, an LSD post hoc test for multiple comparisons revealed a significant difference between each two groups. An independent sample t-test revealed significant differences between time periods for groups II, III, and IV, but there were no significant differences between the time periods for group I. CONCLUSION Injecting GMSCs at the cut borders and gluing the cut area with autologous fibrin glue ameliorates the regeneration of partially dissected submandibular salivary gland better than using fibrin glue alone.

In vivo association of immunophenotyped macrophages expressing CD163 with PDGF-B in gingival overgrowth-induced by three different categories of medications

AIMS This study was carried out to identify and outline the degree of relationship between immunophenotyped macrophages expressing CD163 and PDGF-B in cyclosporine-A, phenytoin, and nifedipine-induced gingival overgrowth. METHODS Eighty adult male albino rats were selected and divided into four equal groups. Group I received no treatment. Rats of groups II, III, and IV were administered cyclosporine-A, phenytoin, and nifedipine, respectively. Routine tissue processing was carried out for staining with CD163 and PDGF-B. The results of this study were analyzed statistically. RESULTS Group I exhibited score 0 gingival overgrowth while group II yielded score 3 with blunt and bulbous gingival crests. Rats of group III showed score 2 with knife edge and group IV revealed less pronounced gingival overgrowth and mostly the gingival crest was knife edge. Group II had the highest mean value for CD163 while group I showed the lowest value. In addition, group II had the highest mean value for PDGF-B while group I showed the lowest value. Statistically, there was an overall significant difference between the studied groups as well as between each two groups. CONCLUSION Strong association exists between immunophenotyped macrophages expressing CD163 and PDGF-B in GO induced by these medications. In addition, CD163 and PDGF-B upregulated in cyclosporine-A-induced GO compared to phenytoin and nifedipine medications.

Biological roles of KGF, CTGF and TGF-β in cyclosporine-A- and phenytoin- induced gingival overgrowth: A comparative experimental animal study

OBJECTIVE To identify the possible biological roles of keratinocyte growth factor (KGF), connective tissue growth factor (CTGF) and transforming growth factor-β (TGF-β) in cyclosporine-A (CsA) and phenytoin (PNT)-induced gingival overgrowth (GO) and to correlate them with each other. METHODS Sixty adult male albino rats were selected and divided into 3 equal groups. Group I rats received no treatment. Group II rats were administrated CsA for 7 weeks. Group III were administrated PNT for the same period. Rats were euthanized at the end of the experiment and routine tissue processing was carried out. The obtained specimens were stained with H&E, KGF, CTGF and TGF-β antibodies. RESULTS One-way MANOVA test for KGF, CTGF and TGF-β revealed an overall significant difference between the different groups (P<0.001). LSD post hoc test for multiple comparisons revealed a significant difference between each two groups. Two-tailed Pearson correlation for group II revealed non-significant weak positive correlations between KGF & CTGF and between CTGF & TGF-β. Non-significant weak negative correlation was found between KGF & TGF-β. Meanwhile, group III revealed non-significant weak positive correlation between KGF & TGF-β and between CTGF & TGF-β. Significant moderate positive correlation was found between KGF & CTGF. CONCLUSION The findings of the present study indicated that KGF, CTGF and TGF-β have biological roles in progression of CsA- and PNT- induced GO. KGF plays a greater role in CsA- induced GO than in PNT- induced GO. Meanwhile, CTGF and TGF-β play a role in PNT- induced GO greater than in CsA- induced GO.

Effects of aqueous cinnamon extract on chemically-induced carcinoma of hamster cheek pouch mucosa

This study aimed to investigate the effects of aqueous cinnamon extract (ACE) on 7, 12-Dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamster cheek pouch (HCP) mucosa. Sixty male Syrian hamsters were randomly divided into six equal groups. The hamsters of groups I, II and III received no treatment, DMBA and ACE respectively, for 16 weeks. Groups IV and V were handled as group II and concomitantly treated with ACE for the same period and additionally group V received ACE for other 16 weeks after the stoppage of DMBA application. Group VI hamsters were handled as group III and additionally received DMBA for other 16 weeks after the stoppage of ACE supplementation. Hamsters of each group were euthanized according to the experimental schedule. The buccal pouches were and prepared for H&E stain, PAS reagent, CD3 and PDGF immunohistochemical reactivity. All groups showed dysplastic changes with varying degrees except groups I and III. Deep invasive carcinomas were recorded in 90% of the samples of group II, 60% of group IV, 50% of group V and 40% of group VI. From the previous results, it can be concluded that ACE has the potentiality preventing oral cancer initiation better than inhibiting oral cancer progression.