In vitro effect of sodium fluoride on antioxidative enzymes and apoptosis during murine odontogenesis

J Oral Pathol Med (2010) 39 : 709–714 Excessive fluoride ingestion has been identified as a risk factor for fluorosis and oxidative stress. The oxidative stress results from the loss of equilibrium between oxidative and antioxidative mechanisms that can produce kinase activation, mitochondrial disturbance and DNA fragmentation, resulting in apoptosis. Actually many people are exposed to no‐adverted fluoride consumption in acute or chronic way. The aim of this study was to determine the effect of sodium fluoride on first molar germ in relation to its effect on antioxidative enzymes immunoexpression and apoptosis. Thirty first molar germs from 1‐day‐old Balb/c mice were cultured for 24 h with sodium fluoride (0 mM, 1 mM and 5 mM). Immunoexpression determination of CuZnSod, MnSod, catalase, Bax, Bid, caspase 8, caspase 9, caspase 3 and TUNEL assay were perfomed. Cellular disorganization in ameloblast and odontoblast‐papilla zones was observed. CuZnSod and MnSod immunoexpression decrease in experimental groups. Caspase 8, caspase 3, Bax, Bid increase expression and more TUNEL positive cells in both experimental groups than control, suggest that apoptosis induced by fluoride is related to oxidative stress due to reduction of the enzymatic antioxidant.     

Prognostic significance of Ki-67 nuclear proliferative antigen, bcl-2 protein, and p53 expression in follicular and diffuse large B-cell lymphoma

We analyzed 104 patients with non-Hodgkin’s lymphoma, follicular or diffuse large-B-cell-type lymphoma, in order to evaluate the correlation between clinical characteristics and immunohistochemical parameters. Immunostaining was performed by means of monoclonal antibodies against Ki-67, bcl-2, and p53 expression. Forty-nine of the patients showed follicular lymphoma. A high expression of bcl-2 was found in 93%, high expression of p53 in 57%, and low expression of Ki-67 in 96%. Follicular lymphoma grade III showed a p53 expression (p=0.07) slightly higher than follicular lymphoma grades I and II, not reaching statistical significance. Follicular lymphoma grades I and II tended to express lower Ki-67 and higher levels of bcl-2 expression than grade III (p=0.06). Fifty-five cases showed diffuse large-B-cell lymphoma. Among them, bcl-2 was absent in 39%, whereas p53 and Ki-67 expression were high in 38%. In the diffuse large-B-cell lymphomas, a high bcl-2 expression correlated with stages III and IV (p=0.03) and involvement of more than one extranodal area (p=0.03). High Ki-67 expression was also associated to extranodal involvement of more than one area (p=0.03). Overall survival of patients did not show statistically significant differences regarding Ki-67, bcl-2, and p53 tumoral expression. Prognostic factors for overall survival in the multivariate analysis were age (p=0.02) and LDH (p=0.003). Time to progression was worse among follicular lymphoma with high p53 expression than with mild/moderate p53 expression (p=0.009).     

Elucidation of the effect of plumbagin on the metastatic potential of B16F10 murine melanoma cells via MAPK signalling pathway

Melanoma is the most dangerous form of skin cancer with a very poor prognosis. Melanoma develops when unrepaired DNA damage causes to skin cells to multiply and form malignant tumors. The current therapy is limited by the highly ability of this disease to metastasize rapidly. Plumbagin is a naphthoquinone (5-hydroxy-2-methyl-1, 4-naphthoquinone), isolated from the roots of medicinal plant Plumbago zeylanica, and it is widely present in Lawsonia inermis L. It has been shown that plumbagin has an anti-proliferative and anti-invasive activities in various cancer cell lines; however, the anti-cancer and anti-metastatic effects of plumbagin are largely unknown against melanoma cells. In this study, we evaluated the effect of plumbagin on B16F10 murine melanoma cells . Plumbagin decreased B16F10 cell viability as well as the cell migration, adhesion, and invasion. The molecular mechanism was studied, and plumbagin downregulated genes relevant in MAPK pathway, matrix metalloproteinases (MMP's), and cell adhesion. Furthermore, plumbagin elevated the expression of apoptosis and tumors suppressor genes, and genes significant in reactive oxygen species (ROS) response. Taken together, our findings suggest that plumbagin has an anti-invasion and anti-metastasis effect on melanoma cancer cells by acting on MAPK pathway and its related genes.     

Maternal common mental disorders and infant development in Ethiopia: the P-MaMiE Birth Cohort

Background  

Chronicity and severity of early exposure to maternal common mental disorders (CMD) has been associated with poorer infant development in high-income countries. In low- and middle-income countries (LAMICs), perinatal CMD is inconsistently associated with infant development, but the impact of severity and persistence has not been examined.     

High seasonal variation in entomologic inoculation rates in Eritrea, a semi-arid region of unstable malaria in Africa

Entomologic studies were conducted in eight villages to investigate the patterns of malaria transmission in different ecologic zones in Eritrea. Mosquito collections were conducted for 24 months between September 1999 and January 2002. The biting rates of Anopheles arabiensis were highly seasonal, with activity concentrated in the wet season between June and October in the highlands and western lowlands, and between December and March in the coastal region. The biting rates in the western lowlands were twice as high as in the western escarpment and 20 times higher than in the coastal region. Sporozoite rates were not significantly different among villages. The risk of infection ranged from zero on the coast to 70.6 infective bites per year in the western lowlands. The number of days it would take for an individual to receive an infective bite from an infected An. arabiensis was variable among villages (range = 2.8-203.1 days). The data revealed the presence of only one main malaria transmission period between July and October for the highlands and western lowlands. Peak inoculation rates were recorded in August and September (range = 0.29-43.6 infective bits/person/month) at all sites over the two-year period. The annual entomologic inoculation rates (EIRs) varied greatly depending on year. The EIR profiles indicated that the risk of exposure to infected mosquitoes is highly heterogeneous and seasonal, with high inoculation rates during the rainy season, and with little or no transmission during the dry season. This study demonstrates the need to generate spatial and temporal data on transmission intensity on smaller scales to guide targeted control of malaria operations in semi-arid regions. Furthermore, EIR estimates derived in the present study provide a means of quantifying levels of exposure to infected mosquitoes in different regions of the country and could be important for evaluating the efficacy of vector control measures, since Eritrea has made significant steps in reducing the burden of malaria based on the Roll Back Malaria initiative of the World Health Organization.     

Prevalence of dental caries and associated factors among 12 years old students in Eritrea

Background

Dental caries is one of the most prevalent diseases of childhood in developing countries. However, there is a paucity of epidemiological data on the prevalence and associated factors of dental caries in Eritrea. The objective of this study was to assess the prevalence and associated factors of dental caries among 12 years old school children in Eritrea.

Methods

A school based cross sectional study was conducted among 225 twelve years old students in two selected schools. One school from randomly selected urban and rural subzones of the country were selected. WHO adopted questionnaire and a standard checklist were used to collect relevant data. To assess dental caries, two examiners were calibrated by a certified dentist and inter observer agreement was calculated using the Cohen’s Kappa statistic (0.82). All data analysis was done using SPSS version 20.

Results

The prevalence of dental caries was 78%, without significant difference between males (78%) and females (79%).The mean DMFT value was 2.50 (±2.21). The decayed component contributed 98.3% of the score as it had 2.44 (±1.2) share to the mean DMFT value. The first molar was the most affected tooth with a DMFT value of 1.55 (±1.36). The mean significant caries index score (SiC) was 4.97 (±1.9) which is higher than the upper limit of SiC value of 3 set by the WHO as a global average. More than half of the respondents had never visited a dentist and out of the students who had utilized a dental health facility, 82% of visits were due to dental pain while visits for regular checkups were cited by only 6.6% of the respondents.

Conclusion

Dental caries was found to be a common public health problem among 12 years old Eritrean students. The prevalence of dental caries, mean DMFT and SiC scores were higher than the average score of other developing countries. Gaps in dental health service utilization, dental health practices and suboptimal water fluoride levels contribute to poor dental health among school children in Eritrea.