Implications of genetic variations, differential gene expression, and allele-specific expression on metformin response in drug-naïve type 2 diabetes.

PURPOSE: Metformin is widely used to treat type 2 diabetes mellitus (T2DM) individuals. Clinically, inter-individual variability of metformin response is of significant concern and is under interrogation. In this study, a targeted exome and whole transcriptome analysis were performed to identify predictive biomarkers of metformin response in drug-naïve T2DM individuals. METHODS: The study followed a prospective study design. Drug-naïve T2DM individuals (n = 192) and controls (n = 223) were enrolled. T2DM individuals were administered with metformin monotherapy and defined as responders and non-responders based on their glycated haemoglobin change over three months. 146 T2DM individuals were used for the final analysis and remaining samples were lost during the follow-up. Target exome sequencing and RNA-seq was performed to analyze genetic and transcriptome profile. The selected SNPs were validated by genotyping and allele specific gene expression using the TaqMan assay. The gene prioritization, enrichment analysis, drug-gene interactions, disease-gene association, and correlation analysis were performed using various tools and databases. RESULTS: rs1050152 and rs272893 in SLC22A4 were associated with improved response to metformin. The copy number loss was observed in PPARGC1A in the non-responders. The expression analysis highlighted potential differentially expressed targets for predicting metformin response (n = 35) and T2DM (n = 14). The expression of GDF15, TWISTNB, and RPL36A genes showed a maximum correlation with the change in HbA1c levels. The disease-gene association analysis highlighted MAGI2 rs113805659 to be linked with T2DM. CONCLUSION: The results provide evidence for the genetic variations, perturbed transcriptome, allele-specific gene expression, and pathways associated with metformin drug response in T2DM.

EUGLYCEMIC DIABETIC KETOACIDOSIS (EDKA) IN A PATIENT RECEIVING DAPAGLIFLOZIN.

SGLT-2 inhibitors have gained importance in recent years because of their cardio-protective and reno-protective properties in diabetes. SGLT-2 inhibitors, when introduced in diabetic patients, may cause euglycemic diabetic ketoacidosis. A 55-year-old woman presented with low-grade fever, vomiting, and lethargy. She was started on dapagliflozin two years back. On workup, she was diagnosed with euglycemic diabetic ketoacidosis (EDKA) and was managed accordingly. She improved clinically while her dapagliflozin was stopped. With a literature search, we have identified 15 case reports of EDKA with dapagliflozin since 2015. There are no standard guidelines regarding the monitoring of patients for this rare but potentially morbid complication. Moreover, the exact mechanism for this is unknown. Various precipitating factors are linked with SGLT-2 inhibitors in promoting EDKA. We recommend that customary plans should comprise educating the patient about this rare complication before commencing medication, close follow-up with serial electrolyte monitoring, and discontinuing medications in the state of infection, dehydration and recent surgery and serious illness requiring hospitalization.

Insight into the epitaxial encapsulation of Pd catalysts in an oriented metalloporphyrin network thin film for tandem catalysis.

A palladium catalyst (Pd-Cs) encapsulated metalloporphyrin network PIZA-1 thin film with bifunctional properties has been developed through a modified epitaxial layer-by-layer encapsulation approach. Combining the oxidation activity of Pd-Cs and the acetalization activity of the Lewis acidic sites in the PIZA-1 thin film, this bifunctional catalyst of the Pd-Cs@PIZA-1 thin film exhibits a good catalytic activity in a one-pot tandem oxidation-acetalization reaction. Furthermore, the surface components can be controlled by ending the top layer with different precursors in the thin film preparation procedures. The catalytic performances of these thin films with different surface composites were studied under the same conditions, which showed different reaction conversions. The result revealed that the surface component can influence the catalytic performance of the thin films. This epitaxial encapsulation offers a good understanding of the tandem catalysis for thin film materials and provides useful guidance to develop new thin film materials with catalytic properties.

Facile Synthesis of Metal-Loaded Porous Carbon Thin Films via Carbonization of Surface-Mounted Metal-Organic Frameworks.

We report a facile approach to prepare metal-nanocatalyst-incorporated carbon thin films with uniform size distribution via carbonization of surface-mounted metal-organic frameworks (SURMOFs) and metal oxo-clusters loaded SURMOF. The calcinated thin films have high performance of methylene blue degradation and the reduction of nitrobenzene. This study describes a general strategy for preparing various nanoparticle-impregnated porous carbon thin films for applications in catalysis.

Genetic Variants Identified from GWAS for Predisposition to Type 2 Diabetes Predict Sulfonylurea Drug Response.

BACKGROUND: Several SNPs were identified through GWAS for their association with type 2 diabetes which has implications to pancreatic ß-cell physiology. OBJECTIVE: We aimed to study the role of risk alleles of TCF7L2, KCNJ11, CDKN2A, CDKAL1, IGF2BP2, SLC30A8 and KCNQ1 along with pharmacokinetic variants in response to sulfonylureas. METHOD: We performed a prospective study on 209 newly diagnosed subjects; treatment naive T2D subjects were recruited. Individuals were started with glibenclamide monotherapy and followed-up for 12 weeks. Genotyping was done, using PCR-RFLP and TETRA-ARMS PCR and confirmed by DNA sequencing. RESULTS: In univariate regression analysis, KCNJ11 (rs5219) was only the predictor for glibenclamide treatment failure. CONCLUSION: The present data suggests a possible role of KCNJ11 gene in altered response to glibenclamide.

Antiinflammatory Steroidal Alkaloids from Sarcococca wallichii of Nepalese Origin.

Bio-assay guided isolation from the plant Sarcococca wallichii Staph. yielded two new steroidal alkaloids: wallichimine A (1) and wallichimine B (2), and five known ones: sarcodinine (3), N-methylpachysamine A (4), alkaloid C (5), dictyophlebine (6), and sarcorine (7). The structures of the compounds were determined using mass spectrometry and NMR spectroscopy techniques. The immunomodulatory potential of compounds was evaluated on different parameters including production of intracellular reactive oxygen species (ROS), nitric oxide (NO) and on proinflammatory cytokine TNF-α. All compounds were found to be potent inhibitors of intracellular ROS produced from isolated neutrophils, except compound 5, which showed a moderate level of inhibition. Compounds 2 and 4 potently inhibited the production of NO (67.9% and 62.5% respectively). Compound 2 showed potent suppression on production of proinflammatory cytokine TNF-α (76.7%). Among all the tested compounds the new compound 2 was found to be the most potent immunosuppressive agent. This study shows that steroidal alkaloids could be lead compounds for anti-inflammatory drug discovery.

Photocatalytic removal of selenite and selenate species: effect of EDTA and other process variables.

TiO2-assisted photocatalysis was employed for the removal of aqueous phase selenite and selenate species in conjunction with EDTA as a hole (h+) scavenger. Findings from the binary selenite/EDTA and selenate/EDTA systems showed high selenite and selenate removal at pH 4 and pH 6, with faster removal kinetics noted for the selenite species compared with the selenate species that showed a gradual change over the reaction course. The noted removal of selenite and selenate was attributed to their reduction by the conduction band electrons (e-). The effect of pH studies indicated high selenite, selenate, and EDTA removal in the acidic pH range, with the following specific trend: pH 4 > pH 6 > pH 12. Different from the EDTA studies, the use of thiocyanate alone did not initiate reduction of selenium oxyanions, and hence, its role as a hole scavenger in the present systems was not evident. However, the addition of EDTA to respective selenite/selenate/thiocyanate system at pH 4 did yield near complete removal of selenite and selenate species. The marginal role of thiocyanate as a hole scavenger was attributed to its negligible adsorption onto TiO2 surface. Furthermore, at pH 4 and within 3 h reaction time, enhanced selenate removal was noted with an increase in its initial concentration from 20 to 100 ppm, with near complete selenate removal noted for both cases. In general, findings from the present work indicate that both selenite and selenate can be successfully removed from the aqueous phase employing the TiO2-mediated photocatalysis and h(+)-scavenging agent EDTA.

Impact of GDP, spending on R&D, number of universities and scientific journals on research publications in pharmacological sciences in Middle East.

OBJECTIVES: Research in pharmacological science is vital to support the health needs of human beings. Measuring the research output provides information that forms the basis of strategic decisions. This study aimed to investigate the impact of Gross Domestic Product (GDP), spending on Research and Development (R&D), number of universities and scientific journals on research documents (papers), citable documents, citations per document and H-index in pharmacological science among Middle East countries. MATERIALS AND METHODS: All the 16 Middle East countries were included in the study. The information regarding GDP, spending on R&D, total number of universities and indexed scientific journals were collected. We recorded the total number of research documents, citable documents, citations per document and H-index in pharmacological science during the period 1996-2011. The main sources for information were World Bank, Web of Science, Journal Citation Reports (Thomson Reuters) and SCI-mago/Scopus. RESULTS: The mean per capita GDP of all the Middle East countries is 18125.49±5386.28 US$, spending on R&D 0.63±0.28% of GDP in US$, number of universities 36.56±11.33 and mean ISI indexed journal are 8.25±3.93. The number of research documents published in pharmacological science among the Middle East countries during the period 1996-2011 is 1344.44±499.34; citable documents 1286.37±476.34; citations per document 7.62± 0.84; and H-index is 30.68±6.32. There was a positive correlation between spending on R&D and citations per documents (r = 0.56, p = 0.02), H-Index (r = 0.56, p = 0.02); number of universities and research documents (r = 0.72, p = 0.002), citable documents (r = 0.72, p = 0.001); ISI indexed journals and research documents (r = 0.88, p = 0.0001), citable documents (r = 0.88, p = 0.0001), H-Index (r = 0.67, p = 0.004). However, there was no correlation between the GDP per capita and research outcome in pharmacological science. CONCLUSIONS: There is a positive association between spending on R&D, number of universities and indexed scientific journals on research outcome in pharmacological science in Middle East.

NH4+-NH3 removal from simulated wastewater using UV-TiO2 photocatalysis: effect of co-pollutants and pH.

The main objective of the present study was to investigate the efficiency of titanium dioxide (TiO2) assisted photocatalytic degradation (PCD) process for the removal of ammonium-ammonia (NH4(+)-NH3) from the aqueous phase and in the presence of co-pollutants thiosulfate (S2O3(2-)) and p-cresol (C6H4CH3OH) under varying mixed conditions. For the NH4(+)-NH3 only PCD experiments, results showed higher NH4 -NH3 removal at pH 12 compared to pH 7 and 10. For the binary NH4(+)-NH3/S2O3(2-) studies the respective results indicated a significant lowering in NH4(+)-NH3 PCD in the presence of S2O32- at pH 7/12 whereas at pH 10 a marked increase in NH4(+)-NH3 removal transpired. A similar trend was noted for the p-cresol/NH4(+)-NH3 binary system. Comparing findings from the binary (NH4(+)-NH3/S2O3(2-) and p-cresol/NH4(+)-NH3) and tertiary (NH4(+)-NH3/S2O3(2-)/p-cresol) systems, at pH 10, showed fastest NH4(+)-NH3 removal transpiring for the tertiary system as compared to the binary systems, whereas both the binary systems indicated comparable NH4(+)-NH3 removal trends. The respective details have been discussed.

Enhanced photocatalytic activity of nafion-coated TiO2.

Photocatalytic degradation (PCD) of aqueous paraquat was accelerated by the addition of either phosphate or sulfate salt. Attachment of these anions to the TiO2 surface possibly results in increased adsorption of the cationic paraquat species and in turn its photocatalysis rate. The same effect was obtained more consistently using the Nafion (an anionic polymer)-coated TiO2. Enhanced PCD of paraquat and some amine compounds was noted. However the anionic and neutral compounds were not affected significantly. Nafion proved to be stable against photocatalysis. It has been suggested that the degradation rate is larger for the cationic compounds with higher pK(B). For a phenol-paraquat-TiO2 system, paraquat degradation did not begin till near-complete phenol removal. Using the Nafion-coated TiO2, both phenol and paraquat degradations started simultaneously. Nevertheless, complete paraquat removal still took longer than phenol.

Diabetes in Bolivia.

OBJECTIVE: To measure the prevalence of diabetes mellitus (DM), hypertension, obesity, and related risk factors in major cities in Bolivia. METHODS: A population-based survey was conducted in four Bolivian cities: La Paz, El Alto, Santa Cruz, and Cochabamba. The total sample size was chosen to be 2,948 persons. The overall response rate was 86%, with the rate varying somewhat among the four cities. DM was diagnosed through an oral glucose tolerance test (OGTT) 2 hours after an overload of 75 grams of glucose, using World Health Organization criteria. RESULTS: The overall prevalence of DM in the four urban areas combined was 7.2% (95% confidence interval (CI): 6.2%-8.3%) and of impaired glucose tolerance (IGT) was 7.8%. A total of 73.1% (95% CI: 65.0%-81.0%) of those previously diagnosed with DM and 73.7% (95% CI: 61.0%-86.4%) of newly diagnosed cases were overweight, according to measurements of body mass index. Hypertension was found in 36.5% (95% CI: 27.6%-45.5%) of known diabetics and in 36.6% (95% CI: 23.0%-50.1%) of newly diagnosed cases, compared to only 15.9% (95% CI: 14.3%-17.5%) among people without DM. The disease was most common among older persons and those with little education. CONCLUSIONS: Diabetes is a genuine public health problem in Bolivia. Further, the high prevalence of IGT that was found suggests that diabetes prevalence will increase in the near future in the country unless prevention strategies are implemented.

The determination of histamine in the Drosophila head.

Histamine is a neurotransmitter at arthropod photoreceptors. Even though the fruit fly, Drosophila melanogaster, is a widely used model in neuroscience research, the histamine content of its nervous system has not so far been reported. We have developed a high performance liquid chromatography (HPLC) method with pre-column o-phtaldialdehyde-mercaptoethanol (OPA-ME) derivatization and electrochemical detection, to determine this amine in Drosophila. The histamine content of the fly's head averages about 2.0 ng per head. In heads of the mutant hdc(JK910), a presumed null for the gene encoding the enzyme that synthesizes histamine, histamine was not detected in measurable amounts. In heads of the mutant sine oculis, which lacks compound eyes, only 28% of this amine was found compared with wild type flies, so histamine is mainly present in the compound eye photoreceptors. Also observed in histamine-deficient mutants was a decrease in the peak which contains a substance having the same retention time as carcinine (beta-alanyl-histamine). Our method was not able to detect compounds previously reported as histamine metabolites in insects. In spite of this, the method we have developed enables the fast and accurate measurement of histamine in the heads of Drosophila, suitable for screening mutants.

Subcellular localization of dystrophin and vinculin in cardiac muscle fibers and fibers of the conduction system of the chicken ventricle.

The subcellular localization of dystrophin and vinculin was investigated in cardiac muscle fibers and fibers of the conduction system of the chicken ventricle by immunofluorescence confocal microscopy. In ventricular cardiac muscle fibers, strong staining with antibody against dystrophin appeared as regularly arranged transverse striations at the sarcolemmal surface, and faint but uniform staining was seen in narrow strips between these striations. In fibers of the ventricular conduction system, the sarcolemma was stained uniformly with this antibody, but strong staining was found as regular striations in many areas and as scattered patches in other areas of the sarcolemma. These intensely stained striations and scattered patches of dystrophin were colocalized with those of vinculin. Because dystrophin striations were located at the level of Z bands of the underlying myofibrils, they were regarded as the concentration of this protein at costameres together with vinculin. In fibers of the conduction system, myofibrils were close to the sarcolemma where dystrophin and vinculin assumed a striated pattern, at some distance from the cell membrane where these proteins exhibited a patchy distribution, and distant from the sarcolemma where dystrophin was uniformly distributed. These data suggest that the distribution patterns of dystrophin reflect the degree of association between the sarcolemma and underlying myofibrils.

A voltage-dependent noradrenaline-sensitive intracellular calcium store in smooth muscle cells of the guinea-pig aorta.

In this study we investigated the effects of K+ depolarization on the contractile responses of guinea-pig aortic smooth muscle to noradrenaline (NA) and caffeine (CAF) in Ca(2+)-free Krebs solution (CafKS). NA (1 microM) or CAF (10 mM) in regular CafKS induced a (termed first) phasic contraction, but responses to a second NA or CAF stimulation were significantly reduced, suggesting a depletion of the common intracellular (NA/CAF sensitive) store previously reported by investigators. After the depletion of this store (i) neither 105 mM KCl CafKS nor 10 mM CAF in this high K+ solution induced contraction; (ii) NA-induced contractions were enhanced by KCl, increasing dose dependently with KCl ranging from 25 to 105 mM; (iii) in 105 mM KCl CafKS repetitive NA stimulations elicited enhanced and nondecreasing responses equal to or greater than the first contraction, suggesting an efficient recycling of intracellular Ca2+. In the presence of 10 microM cyclopiazonic acid NA-induced contraction was enhanced, but the response to a subsequent NA stimulation in the absence of cyclopiazonic acid was greatly reduced, implying an inhibition of the Ca2+ recycling function; (iv) 2.0 mM EGTA (ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid) attenuated the NA-induced contractions in regular and 105 mM KCl CafKS. On the basis of the above results we propose that in the smooth muscle cells of guinea-pig aorta, there are two intracellular Ca2+ stores: a NA/CAF-sensitive store and a voltage-dependent NA-sensitive store with effective Ca2+ recycling capability.

Serotonin depletors, 5,7-dihydroxytryptamine and p-chlorophenylalanine, cause sprouting in the CNS of the adult snail.

The effects of 5,7-dihydroxytryptamine (5,7-DHT) and p-chlorophenylalanine (PCPA) on neuronal morphology were investigated in Achatina fulica by backfilling the cerebrobuccal connective with nickel-lysine. Backfilling 21 days following injections of either 5,7-DHT or PCPA revealed supernumerary staining of fibers in different pathways of the cerebral and buccal ganglia and novel staining of somata in the cerebral ganglia. HPLC measurements confirm that drug treatments led to a 30-46% depletion of serotonin (5-HT) in the buccal ganglia. These results support the role suggested for 5-HT as a neuritogenic modulator and additionally advise caution in the use of pharmacological depletors in studies examining serotonergic function.

The mechanism of [3H]noradrenaline release by histamine and its analogs from the rat vas deferens.

In this study the mechanism by which histamine and H1 and H2 agonists evoked an overflow of radioactivity from rat vasa deferentia preloaded with [3H]noradrenaline was investigated. The overflow evoked by the various agonists was unaffected by the presence of such receptor antagonists as propranolol, phentolamine, cimetidine, or scopolamine. On the other hand, the overflow evoked by all agonists except dimaprit was inhibited by mepyramine and by two well-known neuronal uptake inhibitors, cocaine and desipramine. The inhibition by mepyramine has been attributed to its effect on the neuronal uptake process. Metabolic profile studies showed that 3,4-dihydroxyphenylglycol (DOPEG) was the major constituent in the evoked overflow caused by histamine, 2-methylhistamine, 4-methylhistamine, and dimaprit and that the overflow evoked by 2-pyridylethylamine and 2-thiazolylethylamine consisted predominantly of unchanged noradrenaline. Based on these findings, it is concluded that all of the agonists tested evoke noradrenaline release intraneuronally by entering the adrenergic nerve terminals. While dimaprit might enter by passively diffusing into the adrenergic nerves, other agonists seem to use the neuronal uptake process. Noradrenaline released intraneuronally is subsequently degraded by neuronal monoamine oxidase to form DOPEG. However, there are qualitative and quantitative differences in the metabolic profile of the overflow evoked by various agonists. It is suggested that these differences could arise from their additional properties, such as their effect on the neuronal uptake process and (or) their ability to act as substrate for neuronal monoamine oxidase.

A sensitive method for simultaneous determination of histamine and noradrenaline with high-performance liquid chromatography/electrochemistry.

A simple and reliable high-performance liquid chromatographic method is described for the simultaneous determination of histamine (His), which cannot be directly oxidized, and noradrenaline (NA), which can be directly oxidized within the useful working potential range. The isoindole products formed by precolumn derivatization of His and NA with o-phthalaldehyde (OPA) and 2-mercaptoethanol (2-ME) yielded a linear relationship of detection between the electrochemical signal and the compound content to a minimum detectable limit of 50 pg (signal-to-noise ratio = 3:1) for both compounds at 0.5 nA of detector range. Without 2-ME, OPA derivatives of both His and NA were not detectable electrochemically at the oxidation potential range from 0 to + 1 V. Although the peak potential was +0.85 V for both His and NA, we used +0.7 V for both compounds to keep background noise minimal. The capacity factors of some electrochemically interfering compounds were also determined. The significance of OPA/2-ME derivative of NA is discussed relative to the direct oxidation of catecholamines. An example of a practical application of the method to the determination of His and NA in rat cardiac tissue is presented.

Near-drowning: fresh, salt, and cold water immersion.

Near-drowning and immersion hypothermia are important, preventable causes of mortality and morbidity. The most important consequences of an immersion accident are hypoxia and its effects on the cardiovascular system and the CNS. The mammalian diving reflex and hypothermia may offer some protection to the CNS despite prolonged hypoxia. The initial management of a nearly drowned victim must be focused on reversal of hypoxemia and acidosis. Prompt and effective on-site CPR is of paramount importance in ensuring optimal survival. The presence of immersion hypothermia must be recognized. Hypothermic patients should be managed according to the severity and the duration of hypothermia. Active external rewarming is adequate for acute and mild hypothermia, whereas active core rewarming may be necessary for chronic and severe hypothermia.