Identification of an Orally Efficacious GPR40/FFAR1 Receptor Agonist

GPR40/FFAR1 is a G protein-coupled receptor predominantly expressed in pancreatic β-cells and activated by long-chain free fatty acids, mediating enhancement of glucose-stimulated insulin secretion. A novel series of substituted 3-(4-aryloxyaryl)propanoic acid derivatives were prepared and evaluated for their activities as GPR40 agonists, leading to the identification of compound 5, which is highly potent in in vitro assays and exhibits robust glucose lowering effects during an oral glucose tolerance test in nSTZ Wistar rat model of diabetes (ED50 = 0.8 mg/kg; ED90 = 3.1 mg/kg) with excellent pharmacokinetic profile, and devoid of cytochromes P450 isoform inhibitory activity.

Non-communicable diseases at a regional hospital in Nepal: Findings of a high burden of alcohol-related disease

Recent global burden of disease reports find that a major proportion of global deaths and disability worldwide can be attributed to alcohol use. Thus, it may be surprising that very few studies have reported on the burden of alcohol-related disease in low income settings. The evidence of non-communicable disease (NCD) burden in Nepal was recently reviewed and concluded that data is still lacking, particularly to describe the burden of alcohol-related diseases (ARDs). Therefore, here we report on NCD burden and specifically ARDs, in hospitalized patients at a regional hospital in Nepal. We conducted a retrospective chart-review that included detailed information on all discharged patients during a four month period. A local database that included sociodemographic information and diagnoses at discharge was established. All doctor-assigned discharge diagnoses were retrospectively assigned ICD-10 codes. A total of 1,139 hospitalized adult patients were included in the study and one third of these were NCDs (n = 332). The main NCDs were chronic obstructive pulmonary disease (COPD) (n = 148, 45%) and ARDs (n = 57, 17%). Patients with ARD often presented with signs of liver cirrhosis and were typically younger men, with a median age at 43 years, from specific ethnic groups. These data demonstrate that severe alcohol-related organ failure in relatively young men contributed to a high proportion of NCDs in a regional hospital in Nepal. These findings are novel and alarming and warrant further studies that can establish the burden of ARDs and alcohol use in Nepal and other similar low-income countries.

Investigation of hydrogen induced fluorescence in C60 and its potential use in luminescence down shifting applications

Herein the photophysical properties of hydrogenated fullerenes (fulleranes) synthesized by direct hydrogenation utilizing hydrogen pressure (100 bar) and elevated temperatures (350 °C) are compared to the fulleranes C₆₀H₁₈ and C₆₀H₃₆ synthesized by amine reduction and the Birch reduction, respectively. Through spectroscopic measurements and density functional theory (DFT) calculations of the HOMO-LUMO gaps of C₆₀H_x (0 ≤ x ≤ 60), we show that hydrogenation significantly affects the electronic structure of C₆₀ by decreasing conjugation and increasing sp³ hybridization. This results in a blue shift of the emission maximum as the number of hydrogen atoms attached to C₆₀ increases. Correlations in the emission spectra of C₆₀H_x produced by direct hydrogenation and by chemical methods also support the hypothesis of the formation of C₆₀H₁₈ and C₆₀H₃₆ during direct hydrogenation with emission maxima of 435 and 550 nm respectively. We also demonstrate that photophysical tunability, stability, and solubility of C₆₀H_x in a variety of organic solvents make them easily adaptable for application as luminescent down-shifters in heads-up displays, light-emitting diodes, and luminescent solar concentrators. The utilizization of carbon based materials in these applications can potentially offer advantages over commonly utilized transition metal based quantum dot chromophores. We therefore propose that the controlled modification of C₆₀ provides an excellent platform for evaluating how individual chemical and structural changes affect the photophysical properties of a well-defined carbon nanostructure.

Effect of iron deficiency anemia and iron supplementation on HbA1c levels - Implications for diagnosis of prediabetes and diabetes mellitus in Asian Indians

BACKGROUND

We investigated the effect of iron deficiency anemia (IDA) on levels of glycated hemoglobin (HbA1c) and to compare its levels before and after iron supplementations.

METHODS

Age and sex matched subjects were enrolled and clustered in 2 groups: IDA (n=62) and healthy controls (HC; n=60). HbA1c levels were estimated by HPLC. Hemogram were estimated by hematology analyser. Serum ferritin (ELISA) and other parameters of iron profile were measured by standard guidelines of ICSH. HbA1c values and iron studies were repeated after 3months of iron supplementation to determine the effect of iron therapy on HbA1c levels.

RESULTS

Significantly higher HbA1c levels were observed in IDA subjects compared to HC (5.51±0.696 v/s 4.85±0.461%, p<0.001). A significant negative correlation was observed between HbA1c and hemoglobin, hematocrit, RBC count, MCH, MCHC and serum ferritin in IDA subjects (r=-0.632, -0.652, -0.384, -0.236, -0.192 and -0.441). Significant decline was noticed in HbA1c levels in IDA subjects after iron supplementation (5.51±0.696 before treatment v/s 5.044±0.603 post-treatment; p<0.001). Post treatment, 70% subjects (14/20) with HbA1c in pre-diabetes range normalised to normal glucose tolerance (NGT) range and out of 6 patients with pre-treatment HbA1c in diabetes range, 5 reverted to pre-diabetes range while 1 of them reverted to the NGT range.

CONCLUSIONS

Caution must be exercised in interpreting the results of HbA1c in patients of IDA and iron deficiency must be corrected before diagnosing diabetes and pre-diabetes solely on the basis of HbA1c criteria.

Magnetoelectric Coupling, Ferroelectricity, and Magnetic Memory Effect in Double Perovskite La3Ni2NbO9

We observe ferroelectricity in an almost unexplored double perovskite La3Ni2NbO9. Ferroelectricity appears below ∼60 K, which is found to be correlated with the significant magnetostriction. A reasonably large value of spontaneous electric polarization is recorded to be ∼260 μC/m(2) at 10 K for E = 5 kV/cm, which decreases signifi- cantly upon application of a magnetic field (H), suggesting considerable magnetoelectric coupling. The dielectric permittivity is also influenced by H below the ferroelectric transition. The magnetodielectric response scales linearly to the squared magnetization, as described by the Ginzburg-Landau theory. Meticulous studies of static and dynamic features of dc magnetization and frequency dependent ac susceptibility results suggest spin-glass state below 29 K. Intrinsic magnetic memory effect is observed from zero-field cooled magnetization and isothermal remanent magnetization studies, also pointing spin-glass state below 29 K. Appearance of ferroelectricity together with a significant magnetoelectric coupling in absence of conventional long-range magnetic order is promising for searching new magnetoelectric materials.

Magnetoelectric coupling and exchange bias effects in multiferroic NdCrO3

We report ferroelectricity around  ∼88 K that appears well below T N (∼25 K), unlike other members of RCrO3 series. A synchrotron diffraction study suggests that the occurrence of ferroelectricity in NdCrO3 is coupled to the structural transformation from centrosymmetric Pnma to a non-centrosymmetric Pna21 space group. A strong magnetoelectric coupling is observed in the electric polarization [P(T)]. This coupling is significantly influenced by the magnetic field cooling effect, suggesting an exchange bias effect in P(T). This exchange bias effect is also revealed by the systematic shift of the magnetic hysteresis loops below T(N). The rare occurrence of an exchange bias effect in both the magnetic and electric polarizations associated with a strong magnetoelectric coupling is of fundamental interest, as well as being attractive for technological applications close to liquid nitrogen temperature.

Discovery of a Potent and Orally Efficacious TGR5 Receptor Agonist

TGR5 is a G protein-coupled receptor (GPCR), activation of which promotes secretion of glucagon-like peptide-1 (GLP-1) and modulates insulin secretion. The 2-thio-imidazole derivative 6g was identified as a novel, potent, and selective TGR5 agonist (hTGR5 EC50 = 57 pM, mTGR5 = 62 pM) with a favorable pharmacokinetic profile. The compound 6g was found to have potent glucose lowering effects in vivo during an oral glucose tolerance test in DIO C57 mice with ED50 of 7.9 mg/kg and ED90 of 29.2 mg/kg.

Breath-hold imaging of the coronary arteries using Quiescent-Interval Slice-Selective (QISS) magnetic resonance angiography: pilot study at 1.5 Tesla and 3 Tesla

BACKGROUND

Coronary magnetic resonance angiography (MRA) is usually obtained with a free-breathing navigator-gated 3D acquisition. Our aim was to develop an alternative breath-hold approach that would allow the coronary arteries to be evaluated in a much shorter time and without risk of degradation by respiratory motion artifacts. For this purpose, we implemented a breath-hold, non-contrast-enhanced, quiescent-interval slice-selective (QISS) 2D technique. Sequence performance was compared at 1.5 and 3 Tesla using both radial and Cartesian k-space trajectories.

METHODS

The left coronary circulation was imaged in six healthy subjects and two patients with coronary artery disease. Breath-hold QISS was compared with T2-prepared 2D balanced steady-state free-precession (bSSFP) and free-breathing, navigator-gated 3D bSSFP.

RESULTS

Approximately 10 2.1-mm thick slices were acquired in a single ~20-s breath-hold using two-shot QISS. QISS contrast-to-noise ratio (CNR) was 1.5-fold higher at 3 Tesla than at 1.5 Tesla. Cartesian QISS provided the best coronary-to-myocardium CNR, whereas radial QISS provided the sharpest coronary images. QISS image quality exceeded that of free-breathing 3D coronary MRA with few artifacts at either field strength. Compared with T2-prepared 2D bSSFP, multi-slice capability was not restricted by the specific absorption rate at 3 Tesla and pericardial fluid signal was better suppressed. In addition to depicting the coronary arteries, QISS could image intra-cardiac structures, pericardium, and the aortic root in arbitrary slice orientations.

CONCLUSIONS

Breath-hold QISS is a simple, versatile, and time-efficient method for coronary MRA that provides excellent image quality at both 1.5 and 3 Tesla. Image quality exceeded that of free-breathing, navigator-gated 3D MRA in a much shorter scan time. QISS also allowed rapid multi-slice bright-blood, diastolic phase imaging of the heart, which may have complementary value to multi-phase cine imaging. We conclude that, with further clinical validation, QISS might provide an efficient alternative to commonly used free-breathing coronary MRA techniques.

Longitudinal extensive transverse myelitis due to tuberculosis: a report of four cases

Tuberculosis of the central nervous system (CNS) accounts for approximately 1% of all cases of tuberculosis and half of these involve the spine. Intramedullary involvement is rare in tuberculosis and usually present in the form of radiculomyelitis, transverse myelitis, intraspinal granulomas, or thrombosis of anterior spinal artery. Transverse myelitis typically extends two or less spinal segments, whereas longitudinal extensive transverse myelitis (LETM) extends three or more spinal segments in length and may occasionally span all the segments of the spinal cord. LETM is most frequently associated with neuromyelitis optica (NMO). Moreover, associations between NMO and active pulmonary tuberculosis have been suggested by a number of case reports and case series. We present here four cases of spinal tuberculosis that presented with LETM and none of them had a clinical profile fulfilling the diagnostic criteria for NMO.

Abstract POSTER-BIOL-1307: Bioenergetic adaptations in chemoresistant ovarian cancer cells

While, normal cells primarily rely on mitochondrial oxidative phosporylation (OXPHOS), cancer cells are known to preferentially take up glucose to produce energy using aerobic glycolysis pathway, described as the ‘Warburg effect’. Recently, this view that all cancer cells are dependent on glycolysis is being challenged. We examined the bioenergetic characteristics of a panel of 10 human ovarian cancer cell lines and 2 immortalized ovarian surface epithelial cell lines, using the Seahorse XF Extracellular Flux analyzer to measure glycolysis and mitochondrial respiration in real time using the outputs of extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) respectively. The mitochondrial bioenergetics was read by taking baseline OCR following sequential addition of oligomycin, FCCP and rotenone/antimycin, which inhibit mitochondrial ATP synthase, uncouple mitochondrial OXPHOS and induce maximal respiration respectively. Glycolytic profile (ECAR) was generated after keeping the cells glucose free followed by sequential addition of glucose to induce glycolysis, oligomycin and 2-deoxy glucose to inhibit glycolysis. The OCR profile showed ovarian cancer cells lines to have diverse mitochondrial bioenergetics and diverse ability to use glycolysis. The OCR:ECAR ratio showed varied bioenergetic organization, with some cells relying heavily on glycolysis or OXPHOS, but most using both pathways equally. A significant positive correlation (correlation coefficient 0.7705; p=0.003) was observed between mitochondrial respiration and glycolysis, confirming that glycolysis dependent cells have lower ATP-linked respiration rates. A similar diversity was observed in the mRNA expression of glycolytic (Glut1 and LDH) and mitochondrial (PGC-1α and CoxVb) genes. These findings highlight the actuality of extreme heterogeneity observed in cancer cells. A unique observation was the distinctive behavior of chemosensitive and resistant cell line pairs. Our panel contained a set of (i) cisplatin sensitive A2780 and resistant C200 cell lines and (ii) taxol sensitive PEO1 and resistant PEO4 cell lines. The resistant cells (C200 and PEO4) displayed higher ECAR and OCR profile compared to the sensitive cells (A2780 and PEO1), indicating an increased utilization of both energy pathways. The OCR:ECAR ratio suggested the sensitive cell lines to be glycolytic and the resistant cell lines to be highly metabolically active. This was further supported by increased mitochondrial function in the resistant cells, measured in terms of augmented fatty acid oxidation and mitochondrial potential in the resistant cells. On inhibition of glycolysis, the resistant cells were able to increase OX-PHOS and maintain their growth, whereas sensitive cells could not increase OX-PHOS and ceased growth. This led us to a novel hypothesis that chemo-resistant ovarian cancer cells exhibit greater plasticity than normal and sensitive cells, making them more adaptable to rearrange their metabolic phenotype according to microenvironment changes and stress, giving them a selective advantage to overcome adverse conditions. Thus, the metabolic diversity could be a means of selecting resilient chemo-resistant cells over a period of cytotoxic insults.

Citation Format: J. Chhina, S. Dar, M. Deshpande, S. Giri, A. Munkarah, R. Rattan. Bioenergetic adaptations in chemoresistant ovarian cancer cells [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1307.

Unusual causes of fungal rhinosinusitis: a study from a tertiary care centre in South India

PURPOSE

The frequency of mycotic infections of the nose and paranasal sinuses has been increasing over the past three decades. Apart from the common causes of fungal rhinosinusitis such as Aspergillus species and Penicillium species, there have been reports of rare and unusual fungi isolated from India and other countries.

OBJECTIVE

The objective of this study is to find out the prevalence of fungal infections of the nose and paranasal sinuses caused by unusual fungal isolates at a tertiary care teaching hospital in South India.

MATERIALS AND METHODS

Duration of the study period was from April 2009 to March 2010. Specimens were collected from the nose and paranasal sinuses of all clinically and radiologically diagnosed cases of rhinosinusitis. All the clinical specimens were processed by standard methods for fungal culture. This included initial screening by 10% potassium hydroxide, inoculation of the specimen onto Sabouraud dextrose agar and incubation at 25°C and 37°C, followed by slide culture and other special techniques wherever necessary. Histopathological examination was also performed for the specimens.

RESULTS

A total of 60 specimens were received for fungal culture from cases of rhinosinusitis during the period, out of which 45 showed no growth. There were nine cases of Aspergillus flavus, 1 each of Aspergillus fumigatus and Penicillium species. The rest four specimens grew rare fungal isolates, i.e. Acremonium sp., Scedosporium apiospermun, Cladosporium cladosporioides and Lasiodiplodia theobromae. Histopathological findings were also positive for these four cases.

CONCLUSION

Apart from the common causes, unusual fungal pathogens were isolated from cases of rhinosinusitis during the study period, which is in accordance with similar reports from other parts of India and some other countries.

Antibiotic Use, Its Resistance in Nepal and Recommendations for Action: A Situation Analysis

Antibiotics are crucial, life-saving medicines in the fight against infectious disease, but resistance to these drugs is growing all over. This article presents key findings from a detailed situation analysis produced by the Global Antibiotic Resistance Partnership (GARP)-Nepal working group. In the absence of nationally-representative surveillance, it is not possible to fully describe antibiotic resistance in the country, but many important bacterial pathogens are highly resistant to most first-line and some second-line antibiotics, according to available reports. In credible studies, more than half of Escherichia coli, Klebsiella pneumoniae and Streptococcus pneumoniae isolates tested, and over 30 percent of some Shigella spp. and Vibrio cholerae isolates were resistant to first-line antibiotics. The findings for Neisseria gonorrheae and hospital-acquired Staphylococcus aureus are similar. Antibiotic use in animal food is poorly documented in Nepal, but it is commonly acknowledged to be widespread, contributing to the overall antibiotic resistance burden. The volume of veterinary antibiotic sales in Nepal rose over 50 percent from 2008 to 2012, most through retailers without veterinarian prescription. Antibiotics are necessary to treat infections in animals, but they are also used extensively for preventing disease, a use that can be restricted without jeopardizing animal or human health. They may also be used for promoting animal growth, which can be eliminated with no health consequences. Nepal has made important advances in reducing mortality and morbidity and increasing health coverage, but has not yet taken steps to address antibiotic resistance. The GARP-Nepal working group outlines the components of a national strategy on antibiotic resistance, consistent with the recent call by the World Health Organization for national action plans, to be developed collaboratively with stakeholders and partners from government and all relevant sectors.

Luffa echinata: healer plant or potential killer

Bristly luffa (Luffa echinata), a member of the cucurbitaceae family is an Ayurvedic medicinal plant, which has been used in the traditional system of medicine for variety of symptoms. The active constituents like cucurbitacin, saponin, echinatin, β-Sitosterol, oleanolic acid and flavonoids have important pathophysiological effects on human body. However, there is no earlier published report of any toxicity on humans. We report a case of a 50-year-old gentleman, who presented with gastrointestinal bleeding, deranged liver function and shock following consumption of dried fruits of Luffa echinata soaked overnight in water. He had antral gastritis and duodenal erosions on upper gastrointestinal endoscopy and was managed conservatively and recovered completely.

Two dimensional magnetic correlation in the unconventional corrugated layered oxides (Ba,Sr)₄Mn₃O₁₀

Both Ba4Mn3O10 and Sr4Mn3O10 crystallize in an orthorhombic crystal structure consisting of corrugated layers containing Mn3O12 polydedra. The thermal variation of magnetic susceptibility of the compositions consists of a broad hump like feature indicating the presence of low dimensional magnetic correlation. We have systematically investigated the magnetic data of these compounds and found that the experimental results match quite well with the two dimensional Heisenberg model of spin-spin interaction. The two dimensional nature of the magnetic spin-spin interaction is supported by the low temperature heat capacity data of Ba4Mn3O10. Interestingly, both the samples show dielectric anomaly near the magnetic ordering temperature indicating multiferroic behavior.

Nickel doped nanohydroxyapatite: vascular endothelial growth factor inducing biomaterial for bone tissue engineering

Biomaterial induced activation of vascular endothelial growth factor (VEGF) pathway for angiogenesis is now gaining recognition as an effective option for tissue engineering.

Candidemia in intensive care unit patients: a one year study from a tertiary care center in South India

BACKGROUND

The occurrence of candidemia is on a rise worldwide. Non-albicans Candida species have emerged as major causes of candidemia in many countries. Added to it is the problem of antifungal resistance in Candida isolates.

OBJECTIVES

To find out the prevalence of candidemia in our intensive care unit (ICU) setup along with the antifungal susceptibility pattern of Candida isolates and various risk factors associated with candidemia.

MATERIALS AND METHODS

All Candida isolates from blood stream infections of ICU patients were included in the 1 year study period (November 2008-October 2009). The isolates were speciated using various phenotypic tests. Antifungal susceptibility testing was done by disk diffusion methods according to Clinical and Laboratory Standards Institute guidelines and also using CANDIFAST. Various risk factors associated with the development of candidemia were looked into.

RESULTS

A total of 39 Candida isolates were isolated during the study period of 1 year (prevalence of 0.65%). Candida tropicalis (74.35%) was the most common isolate followed by Candida albicans, Candida parapsilosis, Candida krusei and Candida glabrata. All the 39 Candida isolates (100%) were sensitive to amphotericin B while 12 isolates (30.8%) were resistant to fluconazole. The risk factors commonly associated with candidemia patients were long term antibiotic therapy (64.1%), use of central venous catheters (56.4%), urinary catheters (53.9%), steroid therapy (35.9%) and diabetes mellitus (33.3%).

CONCLUSION

Candidemia is emerging as a significant problem in hospitalized patients, especially in ICU setups. Non-albicans Candida species are the major cause of candidemia as found in our study and few other studies in India. Multicentric studies involving many hospitals are required to know the true prevalence of candidemia and the status of antifungal drug resistance among Candida isolates in our country.