Evaluation of Salivary Alkaline Phosphatase and Glutathione Peroxidase Levels in Diabetic and Nondiabetic Participants With and Without Smoking Habits: A Case-Control Study.

Background: The majority of the current evidence suggests that tobacco smoking increases the risk of diabetes. Salivary alkaline phosphatase (ALP) and glutathione peroxidase (GSHPx) considered a biomarker to detect various oral diseases. Several studies suggest that smoking habits tend to alter ALP and GSHPx levels. However, at present, there is no much information about these enzymes in smokers with diabetes. Hence, the study aimed to evaluate the status of salivary ALP and GSHPx levels in diabetic and nondiabetic participants with and without smoking habits. Materials and Methods: This case-control study was approved by the Institutional Ethical Committee. A total of 60 male participants between the age group 35-50 years were recruited. Informed consent was obtained from participants. Participants were categorized into four groups: Group I - Smokers with diabetes (n = 15), Group II - Smokers without diabetes (n = 15), Group III - Nonsmoker with diabetes (n = 15), and Group IV - Nonsmoker without diabetes (n = 15). Salivary ALP levels and GSHPx activity were measured by colorimetric assay. Data were compared between groups using the one-way analysis of variance, followed by a Bonferroni post-hoc test. Results: Nonsmoker diabetic participants demonstrated significantly higher ALP levels as compared to other groups (P < 0.05). We observed significantly lower levels of ALP in smokers with diabetes (P < 0.05). We observed a significant decrease in GSHPx activity in smokers with diabetes compared to all other groups (P < 0.05). Conclusions: Salivary ALP can be used as a clinical biomarker to be correlated for evaluating diabetes. GSHPx activity can be used to understand the response of supplementation therapy in smokers with diabetes.

Association of geographic tongue and fissured tongue with ABO blood group among adult psoriasis patients: a novel study from a tertiary care hospital in Saudi Arabia.

OBJECTIVE: We aimed to determine if there was any association between geographic tongue (GT) and fissured tongue with ABO blood group among adult psoriasis patients in Saudi Arabia. STUDY DESIGN: This hospital-based cross-sectional study included 100 consecutive new adult patients diagnosed with psoriasis and 100 case-matched participants in the control group (nonpsoriatic). Sociodemographic and dermatologic parameters, intraoral lesions (GT and fissured tongue), and ABO blood grouping and immunoglobulins were recorded and evaluated using χ2 or Fisher's exact test. RESULTS: A total of 74% of patients had an early age of onset, and 48% of them reported this disease in their parents. A total of 76% of those with generalized psoriasis had plaque type, whereas 78% with the localized type had pustular lesions. A total of 70% of psoriatic patients had O Rh-positive blood; 63% of tongue lesions seen in these patients were GT, and it was most prominent in O Rh-positive (64.28%) and O Rh-negative (62.50%) blood types. GT was prevalent among women (75.6%). CONCLUSIONS: This study found a positive association of both GT and fissured tongue in this population of adult patients with psoriasis compared with a case-matched control population without psoriasis.

Structure of a diguanylate cyclase from Thermotoga maritima: insights into activation, feedback inhibition and thermostability.

Large-scale production of bis-3'-5'-cyclic-di-GMP (c-di-GMP) would facilitate biological studies of numerous bacterial signaling pathways and phenotypes controlled by this second messenger molecule, such as virulence and biofilm formation. C-di-GMP constitutes also a potentially interesting molecule as a vaccine adjuvant. Even though chemical synthesis of c-di-GMP can be done, the yields are incompatible with mass-production. tDGC, a stand-alone diguanylate cyclase (DGC or GGDEF domain) from Thermotoga maritima, enables the robust enzymatic production of large quantities of c-di-GMP. To understand the structural correlates of tDGC thermostability, its catalytic mechanism and feedback inhibition, we determined structures of an active-like dimeric conformation with both active (A) sites facing each other and of an inactive dimeric conformation, locked by c-di-GMP bound at the inhibitory (I) site. We also report the structure of a single mutant of tDGC, with the R158A mutation at the I-site, abolishing product inhibition and unproductive dimerization. A comparison with structurally characterized DGC homologues from mesophiles reveals the presence of a higher number of salt bridges in the hyperthermophile enzyme tDGC. Denaturation experiments of mutants disrupting in turn each of the salt bridges unique to tDGC identified three salt-bridges critical to confer thermostability.