Organic and inorganic components of aerosols over the central Himalayas: winter and summer variations in stable carbon and nitrogen isotopic composition

The aerosol samples were collected from a high elevation mountain site, Nainital, in India (1958 m asl) during September 2006 to June 2007 and were analyzed for water-soluble inorganic species, total carbon, nitrogen, and their isotopic composition (δ(13)C and δ(15)N, respectively). The chemical and isotopic composition of aerosols revealed significant anthropogenic influence over this remote free-troposphere site. The amount of total carbon and nitrogen and their isotopic composition suggest a considerable contribution of biomass burning to the aerosols during winter. On the other hand, fossil fuel combustion sources are found to be dominant during summer. The carbon aerosol in winter is characterized by greater isotope ratios (av. -24.0‰), mostly originated from biomass burning of C4 plants. On the contrary, the aerosols in summer showed smaller δ(13)C values (-26.0‰), indicating that they are originated from vascular plants (mostly of C3 plants). The secondary ions (i.e., SO4 (2-), NH4 (+), and NO3 (-)) were abundant due to the atmospheric reactions during long-range transport in both seasons. The water-soluble organic and inorganic compositions revealed that they are aged in winter but comparatively fresh in summer. This study validates that the pollutants generated from far distant sources could reach high altitudes over the Himalayan region under favorable meteorological conditions.

A study of structural and functional connectivity in early Alzheimer's disease using rest fMRI and diffusion tensor imaging

BACKGROUND/OBJECTIVES

Alzheimer's disease (AD) is a progressive neurodegenerative condition where in early diagnosis and interventions are key policy priorities in dementia services and research. We studied the functional and structural connectivity in mild AD to determine the nature of connectivity changes that coexist with neurocognitive deficits in the early stages of AD.

METHODS

Fifteen mild AD subjects and 15 cognitively healthy controls (CHc) matched for age and gender, underwent detailed neurocognitive assessment and magnetic resonance imaging (MRI) of resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI). Rest fMRI was analyzed using dual regression approach and DTI by voxel wise statistics.

RESULTS

Patients with mild AD had significantly lower functional connectivity (FC) within the default mode network and increased FC within the executive network. The mild AD group scored significantly lower in all domains of cognition compared with CHc. But fractional anisotropy did not significantly (p < 0.05) differ between the groups.

CONCLUSION

Resting state functional connectivity alterations are noted during initial stages of cognitive decline in AD, even when there are no significant white matter microstructural changes.

Detection of in-vivo chloroquine resistance inPlasmodium falciparumfrom Rameswaram Island, a pilgrim centre in southern India

Resistance to chloroquine (CQ) in Plasmodium falciparum is one of the main causes of the wide-spread resurgence of malaria in India and a challenge to the effective control of the disease. In the pilgrim centre of Rameswaram Island, malaria has persisted despite the various control measures undertaken over the years. When CQ resistance in Rameswaram was investigated in vivo, recrudescent parasitaemias were observed in 25 (58%) of the 43 study subjects who were given CQ and completed follow-up, all occurring between days 10 and 28 (late treatment failures). The results of the msp(1), msp(2) and glurp genotyping of paired samples of P. falciparum, collected on day 0 and the day of recrudescence from 23 of the apparent treatment failures, indicated that 21 (91%) of the 23 were probably true treatment failures. All of the paired samples harboured parasites with the K76T mutation in their pfcrt genes, and subsequent sequencing of nine day-0 samples revealed the SVMNT haplotype in all nine. This is the first report of in-vivo drug resistance in P. falciparum from Rameswaram Island. Such resistance, which is probably the result of the indiscriminate use of CQ and/or the import of malaria from mainland India, warrants a change in the drug regimen used locally for the first-line treatment of uncomplicated, P. falciparum malaria, to make treatment more effective and slow the development and spread of more foci of CQ resistance.

Recurrent urolithiasis following parathyroidectomy for primary hyperparathyroidism

INTRODUCTION

The effect of parathyroidectomy on the incidence of recurrent stone formation is uncertain. We aimed to compare the biochemistry and recurrence rate of urolithiasis in patients with primary hyperparathyroidism (pHPT) and stone formation (SF) and non-stone formation (NSF) with idiopathic stone formers (ISF).

METHODS

Patients with pHPT and SF (Group 1) were identified from a prospective database. pHPT patients and NSF (Group 2) and ISFs (Group 3) were randomly selected from respective databases to form three equal groups. Preoperative and postoperative biochemical data were analysed and recurrent urolithiasis diagnosed if present on follow-up radiology. Out-of-area patients were asked about recurrence via telephone.

RESULTS

From July 2002 to October 2011, 640 patients had parathyroidectomy for pHPT. Of these, 66 (10.3%) had a history of renal colic; one was lost to follow-up. Patient demographics were similar across all three groups. Three months post-parathyroidectomy, Groups 1 and 2 had significantly reduced serum calcium concentrations (p<0.01). Group 1 had lower urinary calcium excretion after parathyroidectomy (p<0.01), but estimated glomerular filtration rate did not change following surgery. During median follow-up of 4.33 years (0.25-9 years) in Groups 1 and 2 and 5.08 years (0.810-8 years) in Group 3, one patient (1.5%) in Group 1 and 16 patients (25%) in Group 3 had recurrent urolithiasis (p<0.01). No Group 2 patients developed stones.

CONCLUSION

Curative parathyroidectomy confers a low recurrence rate for urolithiasis, but does not prevent recurrence in all patients. Further research should aim to identify the risk factors for continued SF in these patients.

Biochanin-A ameliorates behavioural and neurochemical derangements in cognitive-deficit mice for the betterment of Alzheimer’s disease

Biochanin-A (BCA), a potent phytoconstituent, has been previously used as an antitumour, a dopaminergic neuron protective agent, an antioxidant, an anticholinergic and on other pharmacological activities including neuroprotection. The present study was aimed to evaluate the behavioural and neurochemical evidence of BCA in cognitive-deficit mice in scopolamine challenged and natural aged-induced amnesia models in young and aged mice, respectively. BCA has exhibited decrease in the transfer latency and increase in step through latency significantly ( p < 0.001) in scopolamine-treated and natural aged mice of exteroceptive behavioural models such as elevated plus maze and passive shock avoidance paradigm, respectively. A decrease in acetylcholinesterase activity of whole brain was seen in scopolamine and aged mice with standard piracetam (Pira; p < 0.001) and BCA in dose-dependent manner. The antioxidant property of BCA was proven by increase in GSH ( p < 0.01) and decrease in thiobarbituric acid reactive substances level significantly in a scopolamine-challenged and aged mice. The scopolamine-treated mice exhibited significant ( p < 0.01) increase in the content of noradrenalin and dopamine, which is a sign of dementia, and these excess increased neurotransmitters were reversed by BCA 40 mg kg−1 ( p < 0.05), BCA 20 mg kg−1 ( p > 0.05), BCA 10 mg kg−1 ( p < 0.05) and standard Pira ( p < 0.05) when compared with scopolamine group. Furthermore, in histopathology of hippocampus, the Pira and BCA-treated mice were protected from the formation of pyknotic neurons, increases in the viable cells count and decreases in the number of degenerative cells compared with the scopolamine group. Hence, BCA could be potential enough for the betterment of Alzheimer’s disease.

Malaria among the Jarawas, a primitive and isolated tribe on the Andaman islands, India

The Jarawas are a primitive Negrito tribe of the Andaman islands, India. The members of this tribe have been geographically and socially isolated from the other inhabitants of the islands. None had attended a hospital or health unit until 1997, when a Jarawa boy with a fractured leg was taken to a hospital in Port Blair, and successfully treated. Since then, increasing numbers of Jarawas have sought treatment at the hospital and/or begun to make other contact with non-Jarawas on the islands. No malaria had ever been reported in the tribe until 2001, when an outbreak of febrile illness triggered a malariological survey. Malarial parasites, all identified microscopically as Plasmodium falciparum, were detected in the bloodsmears of 30 of the 179 Jarawas investigated. Although most malaria among the non-Jarawa inhabitants of the islands is caused by P. vivax, only P. falciparum was detected when blood samples from 26 of the subjects were investigated in PCR-based assays. Genetic-diversity studies, based on the msp(1) and msp(2) polymorphic markers, also revealed a relatively low level of polymorphism in the P. falciparum parasites infecting the Jarawas, compared with that seen in other areas of India. It seems possible that malarial parasites have only recently reached the Jarawas, as the result of the weakening of the tribe's isolation from other humans on the Andaman islands.

Multiscale macromolecular simulation: role of evolving ensembles

Multiscale analysis provides an algorithm for the efficient simulation of macromolecular assemblies. This algorithm involves the coevolution of a quasiequilibrium probability density of atomic configurations and the Langevin dynamics of spatial coarse-grained variables denoted order parameters (OPs) characterizing nanoscale system features. In practice, implementation of the probability density involves the generation of constant OP ensembles of atomic configurations. Such ensembles are used to construct thermal forces and diffusion factors that mediate the stochastic OP dynamics. Generation of all-atom ensembles at every Langevin time step is computationally expensive. Here, multiscale computation for macromolecular systems is made more efficient by a method that self-consistently folds in ensembles of all-atom configurations constructed in an earlier step, history, of the Langevin evolution. This procedure accounts for the temporal evolution of these ensembles, accurately providing thermal forces and diffusions. It is shown that efficiency and accuracy of the OP-based simulations is increased via the integration of this historical information. Accuracy improves with the square root of the number of historical timesteps included in the calculation. As a result, CPU usage can be decreased by a factor of 3-8 without loss of accuracy. The algorithm is implemented into our existing force-field based multiscale simulation platform and demonstrated via the structural dynamics of viral capsomers.

Simulating microbial systems: addressing model uncertainty/incompleteness via multiscale and entropy methods

Most systems of interest in the natural and engineering sciences are multiscale in character. Typically available models are incomplete or uncertain. Thus, a probabilistic approach is required. We present a deductive multiscale approach to address such problems, focusing on virus and cell systems to demonstrate the ideas. There is usually an underlying physical model, all factors in which (e.g., particle masses, charges, and force constants) are known. For example, the underlying model can be cast in terms of a collection of N-atoms evolving via Newton's equations. When the number of atoms is 10(6) or more, these physical models cannot be simulated directly. However, one may only be interested in a coarse-grained description, e.g., in terms of molecular populations or overall system size, shape, position, and orientation. The premise of this chapter is that the coarse-grained equations should be derived from the underlying model so that a deductive calibration-free methodology is achieved. We consider a reduction in resolution from a description for the state of N-atoms to one in terms of coarse-grained variables. This implies a degree of uncertainty in the underlying microstates. We present a methodology for modeling microbial systems that integrates equations for coarse-grained variables with a probabilistic description of the underlying fine-scale ones. The implementation of our strategy as a general computational platform (SimEntropics™) for microbial modeling and prospects for developments and applications are discussed.

Cognition improving effects of clerodendron phlomidis linn. bark extract in mice

Normal ageing is known to deteriorate memory in human beings. Oxygen free radicals, the harmful byproducts of oxidative metabolism are known to cause organic damage to the living system, which may be responsible for the development of Alzheimer's disease in elderly. Clerodendron phlomidis Linn. (Verbenaceae) is known as Agnimantha in sanskrit. Bark of the plant is used in treating various nervous disorders. In the present study C. phlomidis was investigated for its potential as a nootropic agent in mice. The aqueous extract of the C. phlomidis (100 and 200 mg/kg, p.o.) was administered for 6 successive days to both young and aged mice. Exteroceptive behavioral models such as elevated plus maze and passive avoidance paradigm were employed to evaluate short term and long term memory respectively. Scopolamine, diazepam were used to induce amnesia in mice. To delineate the mechanism by which C. phlomidis exerts nootropic action, its effect on brain acetyl cholinesterase levels were determined. Piracetam was used as a standard nootropic agent. Pretreatment with C. phlomidis (100 and 200 mg/kg, p.o.) for 6 successive days significantly improved learning and memory in mice. It reversed the amnesia induced by scopolamine, diazepam and natural ageing. It also decreased the acetyl cholinesterase levels in the whole brain. The bark of C. phlomidis can be useful in treatment of cognitive disorders such as amnesia and Alzheimer's disease.

Low efficacy of chloroquine: time to switchover to artemisinin-based combination therapy for falciparum malaria in India

Drug resistance in Plasmodium falciparum poses a major threat to malaria control globally; including India. Chloroquine is still the most widely used drug in the country because of its safety and cost effectiveness. Although chloroquine resistance was first reported in 1973 in North Eastern India, the extent of the problem was realized only after the more intensive 28-day drug efficacy studies were used to monitor drug resistance. In the present study, efficacy of chloroquine in treatment of uncomplicated falciparum malaria was investigated using standard World Health Organization (WHO) procedures in three distinct epidemiological settings. The prevalence of molecular markers of drug resistance, Pfcrt K76T, Pfmdr1 N86Y, was also studied. A total of 374 children and adults with uncomplicated P. falciparum malaria were enrolled at six sites in four states, treated with chloroquine and follow-up was done for 28 days. The cumulative incidence of success of chloroquine at Day 28 by the Kaplan Meier analysis in the state of Orissa (District Sundargarh, CHC Bisra and Kuarmunda) was 57 (95% CI 43-68) and 54 (95% CI 40-66); in the state of Jharkhand (District Ranchi, PHC Angara and District Simdega, PHC Jaldega) it was 72 (95% CI 59-81) and 65 (95% CI 50-76); in the state of Goa (District North-Goa, Panaji Town), it was 20 (95% CI 10-2) and in the state of Rajasthan (District Udaipur, PHC Rishabdev), it was 96 (95% CI 85-99). Treatment failure was related to Pfcrt mutations but not Pfmdr mutations. Early treatment failure was observed only in 15.8% out of total failures, probably due to the semi-immune nature of the population. This type of response may give false perception about efficacy of the failing drug to patients, clinicians and National Authorities. In a large country like India it is not feasible to conduct in vivo studies in all districts and lack of direct correlation between molecular markers, in vitro studies and treatment outcome makes it difficult to predict the areas requiring change of policy. In this scenario, it is a challenge for National Programmes to make evidence-based revisions in the drug policy. However, considering the global, especially Southeast Asian, scenario and interpretation of available in vivo data, trends of mutations, availability of effective drugs and support of international donors, India should consider changing the first line treatment, at least for all diagnosed P. falciparum cases.

Pitfalls of internet-accessible diagnostic tests: inadequate performance of a CE-marked Chlamydia test for home use

OBJECTIVES

To evaluate the performance of a Conformitée Européenne (CE)-marked home test for Chlamydia trachomatis (CT) that is available over the internet.

METHODS

A total of 231 eligible women attending the Social Hygiene Clinic (SHC) or Obstetrics-Gynecology (OB-GYN) Clinic in Iloilo City, Philippines were recruited to an evaluation of the HandiLab-C Chlamydia home test (HandiLab-C). One vaginal swab was tested with HandiLab-C on-site and the second in Cambridge, UK with two nucleic acid amplification tests (NAAT), the Roche Amplicor and Abbott m2000. The organism load of NAAT-positive swabs was quantified.

RESULTS

Concordance between the NAATs was high (kappa agreement: 0.984). Using the Abbott assay as the gold standard, the sensitivity and specificity of the Roche assay were 97.4% and 100%, respectively. CT prevalence by Abbott was 8.0% (8/100) in the OB-GYN Clinic and 23.7% (31/131) at SHC. The sensitivity of HandiLab-C was 12.5% (1/8) and 19.4% (6/31) in OB-GYN and SHC respectively, with specificities of 93.5% (86/92) and 88% (88/100) respectively. Overall positive and negative predictive values of HandiLab-C were 28% and 84.5% respectively. No correlation between HandiLab-C performance and organism load (range: 1.3 x 10(2) to 1.4 x 10(7) bacteria/swab) was observed.

CONCLUSIONS

The performance of HandiLab-C is very poor, with the test yielding more false-positive (18/193) than true-positive (7/38) results. It remains accessible via the internet under various brand names and has retained its CE mark. This situation raises serious concerns about the regulation of diagnostic products available via the internet and the standards of certain Notified Bodies that issue the CE mark.