Advances have been made in identifying dental stem cells and their differentiation potential. Five different types of dental stem cells have been isolated from dental soft tissues: dental pulp, apical papilla, dental follicle and periodontal ligament. The characteristic features of these cells have been explored. They express various arrays of biomarkers including those specific for mesenchymal and/or embryonic stem cells. In vitro and in vivo studies have revealed that these stem cells varied in their proliferation and differentiation potential. Recent studies have demonstrated their wide range of plasticity and their potential use for regenerative medicine and dentistry. This article summarizes information available on the different types of dental stem cells and discusses their potential use in regenerative medicine.

Frog skin constitutes a rich source of peptides with broad spectrum antimicrobial activity against strains of antibioticresistant bacteria and fungi and several hundred such peptides from diverse species have been described. However, their therapeutic potential remains to be realized and no anti-infective peptide based upon their structures has yet been adopted in clinical practice. This review assesses potential clinical applications of nine antimicrobial peptides isolated from frog skin (alyteserin-1c, ascaphin-8, brevinin-1BYa, brevinin-2PRa, brevinin-2-related peptide, brevinin-2-related peptide-ERa, kassinatuerin-1, pseudin-2, and temporin-DRa). The multidrugresistant microorganisms targeted include the Gramnegative bacteria Acinetobacter baumannii, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa, the Gram-positive bacterium Staphylococcus aureus, and the opportunistic yeast pathogens Candida spp. Although the naturally occurring peptides show varying degrees of cytotoxicity towards mammalian cells such as erythrocytes, analogs have been developed that retain high antimicrobial potency but are non-hemolytic. Treatment and prevention of acne and periodontal disease are identified as areas in which frog skin antimicrobial peptides might find future applications.

Aim: Dromedary camels are extremely well adapted to periods of water deprivation. The physiological mechanisms underlying this adaptation, however, are imperfectly understood. It is likely that the renin-angiotensin system plays an important role although few studies have addressed this possibility in the camel. Accordingly, the effects of long term dehydration alone and with angiotensin II type 1 receptor blocker, losartan, on whole blood and serum constituents were studied in camels. Methods: Twenty eight male camels 3-4 years old were studied while under shade during summer in the Gulf-region, where the ambient temperature was above 40 degree Celsius. The camels were divided into three groups: a control group (n=6) was allowed free access to feed and water, a dehydration group (n=16) was given food ad-lib during 20 days of total water deprivation, and a dehydration plus losartan (losartan) group (n=6) which received losartan 5 mg/Kg daily by intravenous injection during 20 days of dehydration. Results: The body weight of the losartan group decreased by nearly 39.1% across dehydration whereas the reduction in body weight for the dehydration group was nearly 34.5% compared to controls. There was a significant increase in the packed cell volume (p<0.05) and leucocytes count (p<0.01) in the losartan group compared to controls. However, the mean corpuscular volume was significantly higher (p<0.05) in the dehydration group compared to controls. We observed major, statistically significant increases in serum urea (p<0.01) and creatinine (p<0.05) levels in the dehydration and losartan groups compared to controls. By the end of the period of water restriction, serum levels of gamma glutamyl transferase were significantly (p<0.01) lower in the losartan group compared to controls. Conclusion: The results of our experiment show that dehydration alone or in combination with Angiotensin II receptor blocker has major effects on the biochemical and hematological parameters of the camel blood.