Cadmium pollution and amphibians--Studies in tadpoles of Rana limnocharis

Cadmium is released into the environment in increasing amounts from different natural and anthropogenic activities contaminating the aquatic habitats. Amphibian tadpoles develop in water and hence are likely to be adversely affected by cadmium present in the aquatic environment. We have studied the toxic and genotoxic effects of CdCl2 on the tadpoles of Rana limnocharis. CdCl2 in the concentration range between 0.1 and 0.4 mg/L induced significant mortality in R. limnocharis tadpoles in a dose and time dependent manner. The 10-day LC50 which has more ecological relevance was far less than the 24-h LC50. Tadpoles exposed to CdCl2 metamorphosed at an early age possibly as a survival strategy to move out of the stressful environment. The body weight of the CdCl2 exposed animals at metamorphosis was lower compared to the control individuals which may affect survival and reproductive fitness in adult life. Besides, the average body length of the metamorphosed individuals in the CdCl2 exposed group was higher than the control group. CdCl2 was found to be genotoxic in micronucleus test and comet assay. The ambient concentration of Cd could reach up to 60 μg/L or more. Exposure to 18.5 μg/L of CdCl2 (1% of 24-h LC50) induced significant increase in DNA strand breaks as compared to the control. The present findings demonstrate that presence of cadmium in the aquatic environment can significantly alter the life history traits and cause DNA damage in amphibians and hence, could contribute towards their population decline.

Evaluation of genetic damage in tobacco and arsenic exposed population of Southern Assam, India using buccal cytome assay and comet assay

Ground water is the principal source of drinking water in Assam. Ground water contamination of arsenic in drinking water is a great concern for human health and considered as a human carcinogen. The present cytogenetic biomonitoring study was undertaken to investigate the genotoxic effects associated with people of southern Assam consuming arsenic contaminated water and chewing tobacco. Employing the buccal cytome assay, exfoliated cells were analyzed in 138 individuals of age range 22-42 years and divided into four groups. Group I (n=54) are participants residing in localities where ground water contains arsenic concentration below the permissible limit (<10μg/l) and without any tobacco chewing history. Group II (n=32) participants from the same area but they are tobacco chewers. Group III (n=24) participants from localities where significantly high arsenic contamination in ground water were observed. Whereas the Group IV (n=28) consists of participants from the arsenic contaminated area and also tobacco chewers. Body mass index (BMI) in all the groups are found to be nearly same and in normal range. Statistically significant (P<0.001) increase in genotoxic, cell death parameters and cell proliferation biomarkers were observed in the Group IV compared to other groups. In the comet assay, percent of tail DNA gradually increases among the groups and has statistical significance. Spearman correlation revealed strong positive correlation between the arsenic exposed peoples and the binucleated cells (r=0.4763; P<0.001). Amount of chewing tobacco had significant positive correlation with micronucleus frequency (r=0.268; P<0.05) and karyolitic cells (r=0.217; P<0.05) and also in the percentage of tail DNA (r=0.5532, P<0.001). A statistically significant increase in glucose content and decrease in hemoglobin content as well as acetylcholine esterase in the blood of exposed individuals was observed. Our preliminary study indicate that population exposed to arsenic through drinking water may become more susceptible towards chewing tobacco induced nuclear damage as evaluated by buccal cytome assay and comet assay.

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.

Importance of Choline as Essential Nutrient and Its Role in Prevention of Various Toxicities

Choline is a water-soluble essential nutrient included as a member of the vitamin B12 group owing to its structural similarities with that of the other members of the group. Its roles and functions, however, extend much wider than that of the vitamins with which it is grouped. Choline is vital for maintenance of various key metabolic processes which play a role in the prevention or progression of various health impairments. The occurrence of diseases like neural tube defect (NTD) and Alzheimer’s is prevented by the metabolic role of choline. It is also indispensable for mitigation of various forms of toxic contamination. While adequate level of choline in the body is essential, an excess of choline can result in various forms of disorder. To maintain the optimal level of choline in the body can be a challenge. The vital roles played by choline together with the range of contradictions and problems that choline presents make choline an interesting area of study. This paper attempts to summarize and review some recent publications on choline that have opened up new prospect in understanding the multiple role played by choline and in throwing light on the role played by this wonder essential nutrient in mitigating various forms of toxic contamination.

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.

Sodium arsenite induced changes in survival, growth, metamorphosis and genotoxicity in the Indian cricket frog (Rana limnocharis)

Arsenic contamination of the environment is a matter of great concern. Understanding the effects of arsenic on aquatic life will act as biological early warning system to assess how arsenic could shape the biodiversity in the affected areas. Rapid decline in amphibian population in recent decades is a cause of major concern. Over the years, amphibians have been recognized as excellent bio-indicators of environmental related stress. In the present study, we examined the toxic and genotoxic effects of sodium arsenite in the tadpoles of the Indian cricket frog (Rana limnocharis). Sodium arsenite at different concentrations (0, 50, 100, 200 and 400 μg L(-1)) neither induced lethality nor significantly altered body weight at metamorphosis. However, it accelerated the rate of metamorphosis at higher concentrations, reduced body size (snout-vent length) and induced developmental deformities such as loss of limbs. Besides, at concentration ranges between 100 and 400 μg L(-1), sodium arsenite induced statistically significant genotoxicity at 24, 48, 72 and 96 h of the exposure in a concentration-dependent manner. However, it did not show time effects as the highest frequency was found between 48 and 72 h which remained steady subsequently. The genotoxicity was confirmed by comet assay in the whole blood cells. These findings suggest that arsenic at environmentally relevant concentrations has significant sub-lethal effects on R.limnocharis, which may have long-term fitness consequence to the species and may have similar implications in other aquatic life too.

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.

Curcumin protects metronidazole and X-ray induced cytotoxicity and oxidative stress in male germ cells in mice

Metronidazole (MTZ) is a common antiparasitic and antibacterial drug. The drug and X-ray induced effects in mouse sperm count, sperm head abnormality and some oxidative stress parameters have been studied. Simultaneously the protective role of curcumin has been evaluated. MTZ, 40 mg/kg bw and 13.4 mg/kg bw × 3 days exposure induced abnormal sperm head and reduced total sperm count in Swiss albino mice both after 24 h and 35 days of exposure. However, MTZ treatment in mice receiving X-ray irradiation (0.5 Gy) did not changed the incidence of abnormal sperm population or decrease in the total sperm count. Hepatic glutathione (GSH), superoxide dismutase (SOD) declined significantly during the treatment phase with significant rise in lipid peroxidation of the tissue. The cellular changes were estimated by using lipid peroxidative indices like thiobarbituric acid reactive substances (TBARS). Elevated TBARS is indicative of oxidative stress in treated mice. Furthermore, curcumin pre-treatment apparently reduced the frequency of sperm head abnormality and TBARS induced by MTZ alone or in combination with X-ray and increased the levels of hepatic GSH and SOD. The additive effects of MTZ and X-ray could not be observed with regards to sperm head abnormality and total sperm count in the tested dose range although the cellular antioxidants were found to be significantly lowered and lipid peroxidantion increased. The possible role of MTZ and X-ray inducing sperm abnormality, decreased sperm count and alteration in GSH, SOD and TBARS and defensive role of curcumin have been evaluated.

Magnetic, magnetocaloric and magnetoresistive properties of cubic Laves phase HoAl2 single crystal

We report the magnetization (M) and magnetoresistance (MR) results of HoAl2 single crystals oriented along the ⟨100⟩ and ⟨110⟩ directions. Although HoAl2 has cubic Laves phase structure, a large anisotropy is observed in M and MR below the Curie temperature (TC). A satisfactory correlation between magnetic entropy change (ΔSM) and MR could be established along ⟨110⟩ and also ⟨100⟩, except for the temperature (T) region around which spin reorientation takes place. Large inverse magnetocaloric effect is observed at low T, which is associated with the spin reorientation process in the ⟨100⟩ direction. A theoretical model based on the Landau theory of phase transition can describe the T-variation of -ΔSM for T > TC.

Ochratoxin A induces cytotoxicity, DNA damage and apoptosis in rat hepatocyte primary cell culture at nanomolar concentration

Ochratoxin A (OTA), a mycotoxin produced by several species of Aspergillus and Penicillum, is widely found as a contaminant of food. OTA exhibits a wide range of toxic activities, including nephro- and hepatotoxicity. Although the mechanisms of its genotoxicity and carcinogenicity have been studied before, many controversial results have been published. In addition, the studies were mostly conducted with kidney cells. Therefore, the present study used a primary culture of Wistar rat hepatocytes incubated with increasing concentrations of OTA (2.0-6.0 nanomolar). OTA treatment showed dose-dependent cytotoxicity and DNA damage. Further, flow cytometric analysis of hepatocytes showed dose-dependent apoptosis, suggesting that OTA-induced hepatotoxicity is, may be partly, mediated by apoptosis. Vascular endothelial growth factor gene, a potent pro-angiogenic in hepatocellular carcinoma and responsible for hepatocyte regeneration, did not show any change with OTA treatment, as analysed by reverse transcription polymerase chain reaction. Thus, the present data indicated OTA-induced rat hepatotoxicity in vitro at nanomolar concentration, which inferred a major possible target other than kidney cells.

Bandgap engineering through nanocrystalline magnetic alloy grafting on reduced graphene oxide

Grafting of nanocrystalline Co₈₀Ni₂₀on reduced graphene oxide causes a significantly large moment (1.2μ_B), ∼10 times localization of conductivity and significant magnetoconductance of hybrid-materials, which is promising toward spintronic applications.