Characterization of Mefenamic Acid-Guaiacol Ester: Stability and Transport Across Caco-2 Cell Monolayers

Purpose. Prodrug of non-steroidal anti-inflammatory drugs (NSAIDs) or NSAIDs linked with guaiacol have been reported to suppress gastrointestinal (GI) toxicity or induce GI protective effect. In this study, mefenamic-guaiacol ester was synthesized and its physicochemical properties, stability, and transport across Caco-2 monolayers were investigated. Methods. Synthesis of the ester was carried out using mefenamic acid, guaiacol, N, N-dimethylaminopyridine, and N, Ndicyclohexylcarbodiimide. The hydrolysis of the ester was investigated in aqueous buffer solutions pH 1-12 as well as in Caco-2 homogenate, human plasma, and porcine liver esterase. Caco-2 cell monolayers were utilized for transport studies. Due to the high lipophilicity of the ester with a calculated logP of 6.15, bovine serum albumin (BSA, 4%) was included in the receiver compartment to obtain a good in vitro-in vivo correlation. Permeation of the ester was assessed with or without the exposure of cells to PMSF, an inhibitor of esterase. Results. The ester was stable at a wide pH range from 1-10. However, it was hydrolyzed by enzymes from porcine liver esterase and Caco-2 homogenate. With the PMSF exposure on the apical (AP) side and in the presence of 4% BSA on the basolateral (BL) side, the transported amount of the ester from AP-to-BL direction was 14.63% after 3 hr with a lag time of 23 min. The Papp for the ester was 4.72 × 10^-6 cm s^-1. Conclusion. The results from hydrolysis studies indicate that this ester is a prodrug. The Papp value suggests the moderate absorption characteristic of the compound. The accumulation of this highly lipophilic ester in Caco-2 cells is reduced in the presence of BSA.     

Cell-mediated immune responses to GAD and beta-casein in type 1 diabetes mellitus in Thailand

We measured the cell-mediated immune response to GAD and bovine beta-casein in 38 type 1 and 37 type 2 diabetic patients who visited diabetic clinics or who were hospitalized in Bangkok, Thailand, and in 43 normal controls, by using a lymphoproliferation assay. Positive results against GAD were found in 29/38 (76.3%) type 1, 6/37 (16.2%) type 2 diabetic patients and 1/43 (2.3%) normal controls. Positive results against bovine beta-casein were found in 18/38 (47.4%), 5/37 (13.5%) and 1/43 (2.3%) of these subjects, respectively. The frequencies of the positive results and the magnitude of the responses to both antigens in type 1 diabetic patients were significantly higher than those in the other two groups (P<0.001). In addition, the prevalence of a positive lymphoproliferative response to these antigens in type 1 diabetic patients was higher than that of anti-GAD antibody positivity in the same group of subjects (26.3%). Thus, the prevalence of positive lymphoproliferative response to GAD in type 1 diabetic patients studied was higher than the prevalence of other autoimmune markers previously reported in type 1 diabetic patients in Thailand.     

A clinical comparison of the new attachment obtained by guided tissue regeneration and coronally positioned flap techniques in the management of human molar furcation defects

The present clinical trial was designed to evaluate the regenerative potential of the periodontal tissue in Class II furcation defects in mandibular molars using reconstructive surgery based on the guided tissue regeneration (GTR) technique versus the coronally positioned flap (CPF) technique. After the completion of the initial phase of therapy and four to six weeks healing period, 20 furcation-involved molars were examined for baseline data which included plaque index, gingival condition, probing depth (PD), probing attachment level (PAL-V, PAL-H) and radiographs. All parameters were reexamined after three, six and twelve months of healing, except PD, PAL-V and PAL-H which were not measured at three and six months. A nonparametric analysis was used. The study showed that there were no significant differences in the mean baseline measurements between the treatment groups. After 12 months following surgical treatment, both GTR and CPF procedures showed gains in new clinical attachment levels. When comparing parameters between the two surgical procedures, GTR molars showed significantly more improvement in probing depth as well as vertical and horizontal attachment level of the interradicular osseous defect than did the CPF molars (p < 0.05). About 80 per cent of the sites treated with the GTR technique showed complete clinical resolution of the furcation problem. CPF therapy reached the same Treatment goal in about 50 per cent of the cases which were treated. Guided tissue regeneration appeared to be more effective in promoting regeneration than the coronally positioned flap.     

A Non-Probiotic Fermented Soy Product Reduces Total and LDL Cholesterol: A Randomized Controlled Crossover Trial

Traditional Asian fermented soy food products are associated with reduced cardiovascular disease risk in prospective studies, but few randomized controlled trials have been conducted in at-risk populations. The aim of this study was to investigate the effect of a commercial non-probiotic fermented soy product on blood lipids in adults with cardiovascular risk biomarkers. In a randomized, crossover, intervention study, 27 men and women (aged 29–75 y) exhibiting at least two risk factors, consumed two packets (12.5 g each) daily of a fermented powdered soy product, or an isoenergic control powder made from germinated brown rice for 12 weeks each. The consumption of the fermented soy product resulted in a significantly greater mean change from baseline (compared to the germinated rice, all p < 0.05) in total cholesterol of −0.23 mmol/L (CI: −0.40, −0.06) compared with 0.14 mmol/L (CI: −0.03, 0.31), respectively; and low density lipoprotein (LDL) cholesterol −0.18 mmol/L (CI: −0.32, −0.04) compared with 0.04 mmol/L (CI: −0.01, 0.018) respectively. This was accompanied by an increase in high density lipoprotein (HDL) cholesterol in the germinated rice group, a decrease in apolipoprotein B (ApoB) in the fermented soy group, and a between-treatment effect in apolipoprotein A1 (ApoA1); however, the ratio of the LDL:HDL and of Apo B:ApoA1 did not differ between the groups. The ratio of total cholesterol:LDL decreased in men in the fermented soy group (p < 0.001). Twenty-four-hour urine collection at the end of each treatment period resulted in an increased excretion expressed as a ratio in μmol/d between treatments of 10.93 (CI: 5.07, 23.54) for daidzein; 1.24 (CI: 1.14, 4.43) for genistein; and, 8.48 (CI: 4.28, 16.80) for glycitein, all p < 0.05. The fermented soy powder consumed by participants in this study without implementing other changes in their typical diets, decreased the total and LDL cholesterol, and may serve as a dietary strategy to manage blood lipids. The trial was registered at ClinicalTrials.gov as {"type":"clinical-trial","attrs":{"text":"NCT03429920","term_id":"NCT03429920"}}NCT03429920.     

Typing of Thai clinical isolates of Mycobacterium leprae and analysis of leprosy transmission by polymorphism of tandem repeats

Mycobacterium leprae isolates from Thai leprosy patients were typed for strain differentiation and analysis of leprosy transmission using the six base tandem repeat, GACATC, in rpoT gene and TTC repeat as genetic markers. M. leprae DNA was isolated from skin biopsies of new untreated leprosy patients living in remote areas or in suburban regions of Thailand where leprosy is in low prevalence. In M. leprae strains of 100 patients, TTC alleles exhibited variations in length with 10 to 30, 33 and 35 repeats, the most common alleles being 15, 16, 17 and 19 repeats. All isolates contained three copies of the six base repeat in rpoT gene. Application of TTC repeats in tracking leprosy transmission in two families with multi-cases identified a single (but different) strain of M. leprae in each family.     

Receptor-based 3D-QSAR studies of checkpoint Wee1 kinase inhibitors

One hundred and seventy-four pyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione derivatives reported as inhibitors of the kinase Wee1 were used for a molecular docking and three-dimensional quantitative structure-activity relationship (3D-QSAR) study. Due to the availability of the three-dimensional structure of the Wee1 kinase a receptor-based alignment strategy was applied. Six available Wee1-inhibitor crystal structures were analyzed using the docking program GOLD resulting in a good reproduction of the experimentally derived position and interaction of the cocrystallized inhibitors. Since only a low correlation between docking scores and inhibitory activities was obtained for the series of 174 inhibitors a receptor-based 3D-QSAR study was performed, dividing the data set into 144 training set molecules and an external test set of 30 compounds. Besides the ligand alignment derived from the docking study we tested several other alignment procedures as basis for the 3D-QSAR analysis. The most predictive model was obtained using the alignment from the GOLD docking study. The CoMFA model was found to be robust (q(LOO)(2)=0.764 and r(2)=0.870). The predictive ability of the model was further examined by carrying out leave-20%-out and leave-50%-out cross-validation (q(2)=0.747 for leave-20%-out and 0.737 for leave-50%-out) and predicting the activities of 30 inhibitors used as external test set (r(pred)(2)=0.790). The graphical analysis of the CoMFA contour plot together with the key residues of the binding pocket provided important insight into the relevant interactions of the inhibitors. The results not only provide information about the essential features of potent Wee1 inhibitors but also show the advantage of using receptor-based alignment for 3D-QSAR analysis.     

Melatonin exerts its analgesic actions not by binding to opioid receptor subtypes but by increasing the release of β-endorphin an endogenous opioid

The occurrence of systematic diurnal variations in pain thresholds has been demonstrated in human. Salivary melatonin levels change following acute pain when other factors that could explain the change have been removed or controlled. Melatonin-induced analgesia is blocked by naloxone or pinealectomy. By using selective radioligands [3H]-DAMGO, [3H]-DPDPE, [3-U69593, and 3H]-nociceptin, we have shown that the bovine pinealocytes contain delta and mu, but not kappa or ORL1 opioid receptor subtypes. In the present study, by using melatonin receptor agonists (6-chloromelatonin or 2-iodo-N-butanoyl-5-methoxytryptamine) or melatonin receptor antagonist (2-phenylmelatonin), we have shown that these agents do not compete with opioid receptor subtypes. However, we observed a time-dependent release of beta-endorphin an endogenous opioid peptide, by melatonin from mouse pituitary cells in culture. Hence, it is suggested that melatonin exerts its analgesic actions not by binding to opioid receptor subtypes but by binding to its own receptors and increasing the release of beta-endorphin.     

The prevalence of periodontal disease and oral hygiene care in Savannakhet Province, Lao People's Democratic Republic.

The objective of this study was to evaluate the prevalence of periodontal diseases in Savannakhet Province, Lao PDR. This survey was conducted 14 years after the country reformed its economic structure towards the free market. Thirty villages were picked by simple random sampling from a total of 1,560 villages. Two thousand four hundred and fifty-three individuals, aged twelve and over, were interviewed about oral hygiene practice, and were examined for periodontal health status using the community periodontal index of treatment needs (CPITN) index. Forty percent of the sample had regular practices, 56.5% occasional practices and 3.5% were ignorant about oral hygiene. Oral hygiene practices were performed in the morning by using a toothbrush (61.1%) and the index finger (24.8%). The cleaning agent was water alone for 68.6% and salt powder for 28%. The prevalence of healthy gingiva was nearly zero in all age groups. Gingival bleeding was very low. The most common periodontal problem was calculus deposits, found in 3-5 sextants of all age groups. The pocket depth was 4-5 mm on average; however a depth of more than 6 mm was not observed.     

Recent advances in renal urate transport: characterization of candidate transporters indicated by genome-wide association studies

Humans have higher serum uric acid levels than other mammalian species owing to the genetic silencing of the hepatic enzyme uricase that metabolizes uric acid into allantoin. Urate (the ionized form of uric acid) is generated from purine metabolism and it may provide antioxidant defense in the human body. Despite its potential advantage, sustained hyperuricemia has pathogenetic causes in gout and renal diseases, and putative roles in hypertension and cardiovascular diseases. Since the kidney plays a dominant role in maintaining plasma urate levels through the excretion process, it is important to understand the molecular mechanism of renal urate handling. Although the molecular identification of a kidney-specific urate/anion exchanger URAT1 in 2002 paved the way for successive identification of several urate transport-related proteins, the entire picture of effective renal urate handling in humans has not yet been clarified. Recently, several genome-wide association studies identified a substantial association between uric acid concentration and single nucleotide polymorphisms in at least ten genetic loci including eight transporter-coding genes. In 2008, we functionally characterized the facilitatory glucose transporter family member SLC2A9 (GLUT9), one of the candidate genes for urate handling, as a voltage-driven urate transporter URATv1 at the basolateral side of renal proximal tubules that comprises the main route of the urate reabsorption pathway, in tandem with URAT1 at the apical side. In this review, recent findings concerning these candidate molecules are presented.     

Papulonecrotic Tuberculid

Eleven cases of papulonecrotic tuberculid (PNT) were seen at the Institute of Dermatology, Bangkok, over a 2-year period (1985 to 1986). The diagnosis was supported clinically by symmetric, scattered, papulopustular necrotic lesions, healed with atrophic scars; strongly positive tuberculin test; histopathologic findings; and a rapid improvement after antituberculous therapy. Despite multiple-drug therapy, three cases had recurrences after discontinuation of treatment. Long-term treatment is recommended for the treatment of PNT.