Role of Constituent Oxides for Thermal Mineralization of o-Dichloro Benzene over Mixed-Oxide-TiO2 Catalysts: A Mechanistic Explanation

Catalysts with V2O5, WO3 and V2O5-WO3 dispersed over TiO2 were synthesized using sol-gel technique and thoroughly characterized by various techniques. The catalysts were evaluated for degradation of ortho-dichloro benzene (o-DCB) in air/helium, a representative probe molecule for polychlorinated dibenzo-para-dioxin and polychlorinated dibenzofuran by employing in situ Fourier-transform infrared spectroscopy (FT-IR spectroscopy). Different intermediate species formed on the surface of the TiO2 supported catalysts through of interaction of sorbate molecules with the lattice and/or gaseous oxygen were investigated in detail. Analysis of vibrational bands, observed during sorption of o-DCB and o-DCB-air mixture as a function of temperature over these catalysts, delineated the role of surface intermediate species such as phenolate, enolates, maleates, carboxylates, carbonates in mineralization of o-DCB. Nature and stability of intermediate species, found to be different over these catalysts, were able to elucidate the catalytic activity trend.

Mapping the genomic landscape of multidrug resistance in Plasmodium falciparum and its impact on parasite fitness

Drug-resistant Plasmodium falciparum parasites have swept across Southeast Asia and now threaten Africa. By implementing a P. falciparum genetic cross using humanized mice, we report the identification of key determinants of resistance to artemisinin (ART) and piperaquine (PPQ) in the dominant Asian KEL1/PLA1 lineage. We mapped k13 as the central mediator of ART resistance in vitro and identified secondary markers. Applying bulk segregant analysis, quantitative trait loci mapping using 34 recombinant haplotypes, and gene editing, our data reveal an epistatic interaction between mutant PfCRT and multicopy plasmepsins 2/3 in mediating high-grade PPQ resistance. Susceptibility and parasite fitness assays implicate PPQ as a driver of selection for KEL1/PLA1 parasites. Mutant PfCRT enhanced susceptibility to lumefantrine, the first-line partner drug in Africa, highlighting a potential benefit of opposing selective pressures with this drug and PPQ. We also identified that the ABCI3 transporter can operate in concert with PfCRT and plasmepsins 2/3 in mediating multigenic resistance to antimalarial agents.

Clinically relevant atovaquone-resistant human malaria parasites fail to transmit by mosquito

Long-acting injectable medications, such as atovaquone, offer the prospect of a "chemical vaccine" for malaria, combining drug efficacy with vaccine durability. However, selection and transmission of drug-resistant parasites is of concern. Laboratory studies have indicated that atovaquone resistance disadvantages parasites in mosquitoes, but lack of data on clinically relevant Plasmodium falciparum has hampered integration of these variable findings into drug development decisions. Here we generate atovaquone-resistant parasites that differ from wild type parent by only a Y268S mutation in cytochrome b, a modification associated with atovaquone treatment failure in humans. Relative to wild type, Y268S parasites evidence multiple defects, most marked in their development in mosquitoes, whether from Southeast Asia (Anopheles stephensi) or Africa (An. gambiae). Growth of asexual Y268S P. falciparum in human red cells is impaired, but parasite loss in the mosquito is progressive, from reduced gametocyte exflagellation, to smaller number and size of oocysts, and finally to absence of sporozoites. The Y268S mutant fails to transmit from mosquitoes to mice engrafted with human liver cells and erythrocytes. The severe-to-lethal fitness cost of clinically relevant atovaquone resistance to P. falciparum in the mosquito substantially lessens the likelihood of its transmission in the field.

Superior Interfacial Contact Yields Efficient Electron Transfer Rate and Enhanced Solar Photocatalytic Hydrogen Generation in M/C3N4 Schottky Junctions

Various literature studies (Table 6) have reported that dispersion of metal nanoparticles (NPs) on graphitic carbon nitride g-C3N4 (M/CN) has considerably improved the photocatalytic hydrogen yield. It is understood that metal NPs create active sites on the surface of CN and act as a cocatalyst. However, the precise changes induced by different metal NPs on the surface of CN still elude us. Here, we report a thorough understanding and comparison of the morphology, metal-support interactions, interfacial charge transfer kinetics, and band characteristics in different M/CN (M = Pt, Pd, Au, Ag, Cu) correlated with photocatalytic activity. Among all metals, Pt/CN was found to be the best performer both under sunlight and UV-visible irradiation. Under sunlight, maximum H2@ 2.7 mmol/h/g was observed over Pt/CN followed by Pd/CN > Au/CN > Ag/CN > Cu/CN ≈ CN. The present study revealed that among all metals, Pt formed superior interfacial contact with g-C3N4 as compared to other metals. The maximum Schottky barrier height (Φb,Pt) of 0.66 V was observed at Pt/CN followed by Φb,Au/CN (0.46 V) and Φb,Pd/CN (0.05 V). The presence of electron-deficient Pt in Pt-XPS, decrease in the intensity of d-DOS of Pt near the Fermi level in VB-XPS, increase in CB tail states, and cathodic shift in Vfb in MS plots sufficiently confirmed strong metal-support interactions in Pt/CN. Due to the SPR effect, Au and Ag NPs suffered from agglomeration and poor dispersion during photodeposition. Finely dispersed Pt NPs (2-4 nm, 53% dispersion) successfully competed with shallow/deep trap states and drove the photogenerated electrons to active metallic sites in a drastically reduced time period as investigated by femtosecond transient absorption spectroscopy. Typically, an interfacial electron transfer rate, KIET,avg, of 2.5 × 1010 s-1 was observed for Pt/CN, while 0.087 × 1010 s-1 was observed in Au/CN. Band alignment/potentials at M/CN Schottky junctions were derived and most favorable in Pt/CN with CB tail states much above the water reduction potential; however, in the case of Pd, these extend much below the H+/H2 potential and hence behave like deep trap states. Thus, in Pd/CN (τ0 = 4200 ps, 49%) and Ag/CN (3870 ps, 53%), electron deep trapping dominates over charge transfer to active sites. The present study will help in designing futuristic new cocatalyst-photocatalyst systems.

Novel insights into the role of long non-coding RNA in the human malaria parasite, Plasmodium falciparum

The complex life cycle of Plasmodium falciparum requires coordinated gene expression regulation to allow host cell invasion, transmission, and immune evasion. Increasing evidence now suggests a major role for epigenetic mechanisms in gene expression in the parasite. In eukaryotes, many lncRNAs have been identified to be pivotal regulators of genome structure and gene expression. To investigate the regulatory roles of lncRNAs in P. falciparum we explore the intergenic lncRNA distribution in nuclear and cytoplasmic subcellular locations. Using nascent RNA expression profiles, we identify a total of 1768 lncRNAs, of which 718 (~41%) are novels in P. falciparum. The subcellular localization and stage-specific expression of several putative lncRNAs are validated using RNA-FISH. Additionally, the genome-wide occupancy of several candidate nuclear lncRNAs is explored using ChIRP. The results reveal that lncRNA occupancy sites are focal and sequence-specific with a particular enrichment for several parasite-specific gene families, including those involved in pathogenesis and sexual differentiation. Genomic and phenotypic analysis of one specific lncRNA demonstrate its importance in sexual differentiation and reproduction. Our findings bring a new level of insight into the role of lncRNAs in pathogenicity, gene regulation and sexual differentiation, opening new avenues for targeted therapeutic strategies against the deadly malaria parasite.

Mapping the genomic landscape of multidrug resistance in Plasmodium falciparum and its impact on parasite fitness

Drug-resistant Plasmodium falciparum parasites have swept across Southeast Asia and now threaten Africa. By implementing a P. falciparum genetic cross using humanized mice, we report the identification of key determinants of resistance to artemisinin (ART) and piperaquine (PPQ) in the dominant Asian KEL1/PLA1 lineage. We mapped k13 as the central mediator of ART resistance and identified secondary markers. Applying bulk segregant analysis, quantitative trait loci mapping and gene editing, our data reveal an epistatic interaction between mutant PfCRT and multicopy plasmepsins 2/3 in mediating high-grade PPQ resistance. Susceptibility and parasite fitness assays implicate PPQ as a driver of selection for KEL1/PLA1 parasites. Mutant PfCRT enhanced susceptibility to lumefantrine, the first-line partner drug in Africa, highlighting a potential benefit of opposing selective pressures with this drug and PPQ. We also identified that the ABCI3 transporter can operate in concert with PfCRT and plasmepsins 2/3 in mediating multigenic resistance to antimalarial agents.

Transmissibility of clinically relevant atovaquone-resistant Plasmodium falciparum by anopheline mosquitoes

Rising numbers of malaria cases and deaths underscore the need for new interventions. Long-acting injectable medications, such as those now in use for HIV prophylaxis, offer the prospect of a malaria "chemical vaccine", combining the efficacy of a drug (like atovaquone) with the durability of a biological vaccine. Of concern, however, is the possible selection and transmission of drug-resistant parasites. We addressed this question by generating clinically relevant, highly atovaquone-resistant, Plasmodium falciparum mutants competent to infect mosquitoes. Isogenic paired strains, that differ only by a single Y268S mutation in cytochrome b, were evaluated in parallel in southeast Asian (Anopheles stephensi) or African (Anopheles gambiae) mosquitoes, and thence in humanized mice. Fitness costs of the mutation were evident along the lifecycle, in asexual parasite growth in vitro and in a progressive loss of parasites in the mosquito. In numerous independent experiments, microscopic exam of salivary glands from hundreds of mosquitoes failed to detect even one Y268S sporozoite, a defect not rescued by coinfection with wild type parasites. Furthermore, despite uniformly successful transmission of wild type parasites from An. stephensi to FRG NOD huHep mice bearing human hepatocytes and erythrocytes, multiple attempts with Y268S-fed mosquitoes failed: there was no evidence of parasites in mouse tissues by microscopy, in vitro culture, or PCR. These studies confirm a severe-to-lethal fitness cost of clinically relevant atovaquone-resistant P. falciparum in the mosquito, and they significantly lessen the likelihood of their transmission in the field.

Effect of milnacipran on brain‑derived neurotrophic factor and oxidative stress biomarkers in patients of major depressive disorder

Emerging hypotheses in the pathophysiology of major depressive disorder (MDD) suggest important role of neurotrophic factors and oxidative stress. This study assessed the effect of milnacipran (a dual serotonin‑noradrenaline reuptake inhibitor) on brain‑derived neurotrophic factor (BDNF) and oxidative stress biomarkers i.e., malondialdehyde (MDA), glutathione‑s‑ transferase (GST) and glutathione reductase (GR) in patients of MDD. Thirty patients (aged 18 to 60 years) with MDD diagnosed by DSM‑IV criteria, with Hamilton Depression Rating scale (HAM‑D) score ≥ 14 were included in the study. Patients were given milnacipran in the doses of 50‑100 mg once daily. Patients were followed up for 12 weeks. HAM‑D score at the start of treatment was 17.8±1.7 which significantly reduced to 8.9±3.1 at 12 weeks of treatment. In responders, the plasma BDNF levels increased significantly at 12 weeks post treatment. There was no significant change in the pre‑ and post‑treatment values of oxidative stress parameters (MDA, GST and GR) after 12 week treatment. Milnacipran is effective and well tolerated in MDD patients, and its therapeutic response is associated with an increase in plasma BDNF levels. However, milnacipran did not affect oxidative stress biomarkers.

mRNA-LNP expressing PfCSP and Pfs25 vaccine candidates targeting infection and transmission of Plasmodium falciparum

Malaria is a deadly disease responsible for between 550,000 and 627,000 deaths annually. There is a pressing need to develop vaccines focused on malaria elimination. The complex lifecycle of Plasmodium falciparum provides opportunities not only to target the infectious sporozoite stage, introduced by anopheline mosquitoes, but also the sexual stages, which are ingested by mosquitoes during blood feeding, leading to parasite transmission. It is widely recognized that a vaccine targeting multiple stages would induce efficacious transmission reducing immunity. Technological advancements offer new vaccine platforms, such as mRNA-LNPs, which can be used to develop highly effective malarial vaccines. We evaluated the immunogenicity of two leading P. falciparum vaccine candidates, Pfs25 and PfCSP, delivered as mRNA-LNP vaccines. Both vaccines induced extremely potent immune responses when administered alone or in combination, which were superior to Pfs25 and PfCSP DNA vaccine formulations. Purified IgGs from Pfs25 mRNA-LNPs immunized mice were highly potent in reducing malaria transmission to mosquitoes. Additionally, mice after three and four immunizations with PfCSP mRNA-LNP provided evidence for varying degrees of protection against sporozoite challenge. The comparison of immune responses and stage-specific functional activity induced by each mRNA-LNP vaccine, administered alone or in combination, also supports the development of an effective combination vaccine without any risk of immune interference for targeting malaria parasites at various life cycle stages. A combination of vaccines targeting both the infective stage and sexual/midgut stages is expected to interrupt malaria transmission, which is critical for achieving elimination goals.

A G358S mutation in the Plasmodium falciparum Na+ pump PfATP4 confers clinically-relevant resistance to cipargamin

Diverse compounds target the Plasmodium falciparum Na⁺ pump PfATP4, with cipargamin and (+)-SJ733 the most clinically-advanced. In a recent clinical trial for cipargamin, recrudescent parasites emerged, with most having a G358S mutation in PfATP4. Here, we show that PfATP4^G358S parasites can withstand micromolar concentrations of cipargamin and (+)-SJ733, while remaining susceptible to antimalarials that do not target PfATP4. The G358S mutation in PfATP4, and the equivalent mutation in Toxoplasma gondii ATP4, decrease the sensitivity of ATP4 to inhibition by cipargamin and (+)-SJ733, thereby protecting parasites from disruption of Na⁺ regulation. The G358S mutation reduces the affinity of PfATP4 for Na⁺ and is associated with an increase in the parasite’s resting cytosolic [Na⁺]. However, no defect in parasite growth or transmissibility is observed. Our findings suggest that PfATP4 inhibitors in clinical development should be tested against PfATP4^G358S parasites, and that their combination with unrelated antimalarials may mitigate against resistance development.

In a recent clinical trial for oral administration of cipargamin in individuals with malaria, there was an emergence of recrudescent parasites with a G358S mutation in PfATP4. In this work, the authors investigate the effect of this mutation on the function of the ATPase, on parasite growth and susceptibility to antimalarial drugs.

Screening the Pathogen Box for Inhibition of Plasmodium falciparum Sporozoite Motility Reveals a Critical Role for Kinases in Transmission Stages

As the malaria parasite becomes resistant to every drug that we develop, the identification and development of novel drug candidates are essential. Many studies have screened compounds designed to target the clinically important blood stages. However, if we are to shrink the malaria map, new drugs that block the transmission of the parasite are needed. Sporozoites are the infective stage of the malaria parasite, transmitted to the mammalian host as mosquitoes probe for blood. Sporozoite motility is critical to their ability to exit the inoculation site and establish infection, and drug-like compounds targeting motility are effective at blocking infection in the rodent malaria model. In this study, we established a moderate-throughput motility assay for sporozoites of the human malaria parasite Plasmodium falciparum, enabling us to screen the 400 drug-like compounds from the pathogen box provided by the Medicines for Malaria Venture for their activity. Compounds exhibiting inhibitory effects on P. falciparum sporozoite motility were further assessed for transmission-blocking activity and asexual-stage growth. Five compounds had a significant inhibitory effect on P. falciparum sporozoite motility in the nanomolar range. Using membrane feeding assays, we demonstrate that four of these compounds had inhibitory activity against the transmission of P. falciparum to the mosquito. Interestingly, of the four compounds with inhibitory activity against both transmission stages, three are known kinase inhibitors. Together with a previous study that found that several of these compounds could inhibit asexual blood-stage parasite growth, our findings provide new antimalarial drug candidates that have multistage activity.

Effective Functional Immunogenicity of a DNA Vaccine Combination Delivered via In Vivo Electroporation Targeting Malaria Infection and Transmission

Plasmodium falciparum circumsporozoite protein (PfCSP) and Pfs25 are leading candidates for the development of pre-erythrocytic and transmission-blocking vaccines (TBV), respectively. Although considerable progress has been made in developing PfCSP- and Pfs25-based vaccines, neither have elicited complete protection or transmission blocking in clinical trials. The combination of antigens targeting various life stages is an alternative strategy to develop a more efficacious malaria vaccine. In this study, female and male mice were immunized with DNA plasmids encoding PfCSP and Pfs25, administered alone or in combination via intramuscular in vivo electroporation (EP). Antigen-specific antibodies were analyzed for antibody titers, avidity and isotype by ELISA. Immune protection against sporozoite challenge, using transgenic P. berghei expressing PfCSP and a GFP-luciferase fusion protein (PbPfCSP-GFP/Luc), was assessed by in vivo bioluminescence imaging and blood-stage parasite growth. Transmission reducing activity (TRA) was evaluated in standard membrane feeding assays (SMFA). High levels of PfCSP- and Pfs25-specific antibodies were induced in mice immunized with either DNA vaccine alone or in combination. No difference in antibody titer and avidity was observed for both PfCSP and Pfs25 between the single DNA and combined DNA immunization groups. When challenged by PbPfCSP-GFP/Luc sporozoites, mice immunized with PfCSP alone or combined with Pfs25 revealed significantly reduced liver-stage parasite loads as compared to mice immunized with Pfs25, used as a control. Furthermore, parasite liver loads were negatively correlated with PfCSP-specific antibody levels. When evaluating TRA, we found that immunization with Pfs25 alone or in combination with PfCSP elicited comparable significant transmission reduction. Our studies reveal that the combination of PfCSP and Pfs25 DNAs into a vaccine delivered by in vivo EP in mice does not compromise immunogenicity, infection protection and transmission reduction when compared to each DNA vaccine individually, and provide support for further evaluation of this DNA combination vaccine approach in larger animals and clinical trials.

Plasmodium falciparum Pf77 and male development gene 1 as vaccine antigens that induce potent transmission-reducing antibodies

Malaria vaccines that disrupt the Plasmodium life cycle in mosquitoes and reduce parasite transmission in endemic areas are termed transmission-blocking vaccines (TBVs). Despite decades of research, there are only a few Plasmodium falciparum antigens that indisputably and reproducibly demonstrate transmission-blocking immunity. So far, only two TBV candidates have advanced to phase 1/2 clinical testing with limited success. By applying an unbiased transcriptomics-based approach, we have identified Pf77 and male development gene 1 (PfMDV-1) as two P. falciparum TBV antigens that, upon immunization, induced antibodies that caused reductions in oocyst counts in Anopheles mosquito midguts in a standard membrane feeding assay. In-depth studies were performed to characterize the genetic diversity of, stage-specific expression by, and natural immunity to these two molecules to evaluate their suitability as TBV candidates. Pf77 and PfMDV-1 display limited antigenic polymorphism, are pan-developmentally expressed within the parasite, and induce naturally occurring antibodies in Ghanaian adults, which raises the prospect of natural boosting of vaccine-induced immune response in endemic regions. Together, these biological properties suggest that Pf77 and PfMDV-1 may warrant further investigation as TBV candidates.

Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding

Malaria remains one of the most important public health problems, causing significant morbidity and mortality. Malaria is a mosquito borne disease transmitted through an infectious bite from the female Anopheles mosquito. Malaria control will eventually rely on a multitude of approaches, which includes ways to block transmission to, through and from mosquitoes. To study mosquito stages of malaria parasites in the laboratory, we have optimized a protocol to culture highly infectious Plasmodium falciparum gametocytes, a parasite stage required for transmission from the human host to the mosquito vector. P. falciparum gametocytes mature through five morphologically distinct steps, which takes approximately 1-2 weeks. Gametocyte culture described in this protocol is completed in 15 days and are infectious to mosquitoes from days 15-18. These protocols were developed to maintain a continuous cycle of infection competent gametocytes and to maintain uninterrupted supply of mosquito stages of the parasite. Here, we describe the methodology of gametocyte culture and how to infect mosquitoes with these parasites using glass membrane feeders.

Heptachlor-induced epithelial to mesenchymal transition in HK-2 cells mediated via TGF-β1/Smad signalling

This study investigated the effect of heptachlor-induced oxidative stress (OS) on transforming growth factor (TGF)-β1-mediated epithelial to mesenchymal transition (EMT) in human renal proximal tubular epithelial (HK-2) cells. Following treatment of HK-2 cells with an increasing concentration of heptachlor (0.01–10 µM) for 24 h, the intracellular reactive oxygen species and malondialdehyde level increased, whereas the glutathione-s-hydroxylase (GSH) level declined significantly in a dose-dependent manner. Pretreatment with N-acetyl cysteine attenuates the heptachlor-induced OS. In this study, we have shown that heptachlor-induced OS regulates the mRNA expression of TGF-β1-mediated Smad signalling genes accompanied by increased nuclear localization of phosphorylated Smad-2 and phosphorylated Smad-3. Furthermore, the m-RNA and protein level of epithelial marker, that is, E-cadherin decreased while the mesenchymal marker, that is, α-smooth muscle actin increased in heptachlor exposed HK-2 cells. In conclusion, heptachlor-induced OS might be responsible for the activation of TGF-β1/Smad signalling which ultimately leads to renal damage by means of EMT.

A mosquito salivary gland protein partially inhibits Plasmodium sporozoite cell traversal and transmission

The key step during the initiation of malaria is for motile Plasmodium parasites to exit the host dermis and infect the liver. During transmission, the parasites in the form of sporozoites, are injected together with mosquito saliva into the skin. However, the contribution of vector saliva to sporozoite activity during the establishment of the initial infection of the liver is poorly understood. Here we identify a vector protein by mass spectrometry, with similarity to the human gamma interferon inducible thiol reductase (GILT), that is associated with saliva sporozoites of infected Anopheles mosquitoes and has a negative impact on the speed and cell traversal activity of Plasmodium. This protein, referred to as mosquito GILT (mosGILT) represents an example of a protein found in mosquito saliva that may negatively influence sporozoite movement in the host and could lead to new approaches to prevent malaria.

Long-acting injectable atovaquone nanomedicines for malaria prophylaxis

Chemoprophylaxis is currently the best available prevention from malaria, but its efficacy is compromised by non-adherence to medication. Here we develop a long-acting injectable formulation of atovaquone solid drug nanoparticles that confers long-lived prophylaxis against Plasmodium berghei ANKA malaria in C57BL/6 mice. Protection is obtained at plasma concentrations above 200 ng ml-1 and is causal, attributable to drug activity against liver stage parasites. Parasites that appear after subtherapeutic doses remain atovaquone-sensitive. Pharmacokinetic-pharmacodynamic analysis indicates protection can translate to humans at clinically achievable and safe drug concentrations, potentially offering protection for at least 1 month after a single administration. These findings support the use of long-acting injectable formulations as a new approach for malaria prophylaxis in travellers and for malaria control in the field.

A Novel Gametocyte Biomarker for Superior Molecular Detection of the Plasmodium falciparum Infectious Reservoirs

Background

Complete malaria eradication and optimal use of transmission-reducing interventions require knowledge of submicroscopic infectious reservoirs among asymptomatic individuals. Even submicroscopic levels of Plasmodium falciparum gametocytes can infect mosquitoes and promote onward transmission. Most efforts to identify gametocyte carriers use polymerase chain reaction amplification of the gametocyte-specific transcript Pfs25.

Methods

To expand the repertoire of biomarkers available for superior gametocyte detection, we compared the gene expression profiles of gametocytes and asynchronous blood-stage P. falciparum parasites by microarray technology. This allowed the identification of 56 molecules abundantly expressed in the gametocyte stage of the parasite. The analytical sensitivity for gametocyte detection was evaluated for 25 genes with the highest expression levels.

Results

One candidate, Pfg17, exhibited superior analytical sensitivity against a panel of gametocyte-spiked whole blood, detecting 10 gametocytes/mL; in comparison, Pfs25 detected only 25.3 gametocytes/mL. Pfg17 also exhibited superior clinical sensitivity, identifying 19.1% more samples from blood-film microscopy-negative Ghanaian children and 40% more samples from asymptomatic adults as gametocyte positive.

Conclusions

Cumulatively, our results suggest Pfg17 is an excellent biomarker for detecting asymptomatic infectious reservoirs otherwise missed by the most sensitive molecular method available. Our study has also improved the repertoire of transmission-stage antigens available for evaluation as candidate vaccines.

Insight into growth of Au-Pt bimetallic nanoparticles: an in situ XAS study

Au-Pt bimetallic nanoparticles have been synthesized through a one-pot synthesis route from their respective chloride precursors using block copolymer as a stabilizer. Growth of the nanoparticles has been studied by simultaneous in situ measurement of X-ray absorption spectroscopy (XAS) and UV-Vis spectroscopy at the energy-dispersive EXAFS beamline (BL-08) at Indus-2 SRS at RRCAT, Indore, India. In situ XAS spectra, comprising both X-ray near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) parts, have been measured simultaneously at the Au and Pt L₃-edges. While the XANES spectra of the precursors provide real-time information on the reduction process, the EXAFS spectra reveal the structure of the clusters formed in the intermediate stages of growth. This insight into the formation process throws light on how the difference in the reduction potential of the two precursors could be used to obtain the core-shell-type configuration of a bimetallic alloy in a one-pot synthesis method. The core-shell-type structure of the nanoparticles has also been confirmed by ex situ energy-dispersive spectroscopy line-scan and X-ray photoelectron spectroscopy measurements with in situ ion etching on fully formed nanoparticles.

Association of organochlorine pesticides with the mRNA expression of tumour necrosis factor-alpha (TNF-α) & cyclooxygenase-2 (COX-2) genes in idiopathic preterm birth

Background & objectives:

Preterm birth (PTB) is an important cause of prenatal death, neonatal morbidity and mortality and adult illness. Increased inflammation occurs in normal parturition, and inflammatory cytokines and oxidative stress are found to be higher in PTB cases. The present study was planned to investigate the association of organochlorine pesticides (OCPs) with mRNA expression of inflammatory pathway genes such as tumour necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2) in preterm delivery (PTD) cases.

Methods:

Maternal blood samples of PTD (n=30) cases and equal number of term delivery (n=30) were collected at the time of labour. Women occupationally exposed to OCPs and other high risk factors such as anaemia, hypertension, bacterial vaginosis, renal and heart disease, diabetes, etc. were excluded. The OCP levels were estimated by gas chromatography, and mRNA expressions of TNF-α and COX-2 genes were analysed using real-time PCR (qPCR).

Results:

Significantly higher levels of β-HCH (beta-hexachlorocyclohexane, 95% CI=2.08-4.633, P=0.001), p’p’-DDE (para, para-dichlorodiphenyldichloroethylene, 95% CI=0.546-2.551, P=0.003), and o’p’-DDD (ortho, para-dichlorodiphenyldichloroethane, 95% CI=0.004-0.690, P=0.047) were observed in maternal blood of PTB cases as compared to term delivery. The mRNA expressions of COX-2 and TNF-α genes were 3.13 and 2.31 folds higher in PTB cases in comparison to term delivery. Linear positive correlations were observed between period of gestation (POG) and ΔCt of COX-2 and TNF-α genes.

Interpretation & conclusions:

Environmental factors such as OCPs may be associated with inflammatory events showing gene-environment interaction in PTB cases. Evaluating the molecular control of inflammation along with gene environment interaction may be used as a model to explore the aetiology of idiopathic PTB cases and may be considered for the prognosis of adverse reproductive outcomes.

Plasmodium falciparum CRK4 directs continuous rounds of DNA replication during schizogony

Plasmodium parasites, the causative agents of malaria, have evolved a unique cell division cycle in the clinically relevant asexual blood-stage of infection¹. DNA replication commences approximately halfway through the intracellular development following invasion and parasite growth. The schizont stage is associated with multiple rounds of DNA replication and nuclear division without cytokinesis resulting in a multinucleated cell. Nuclei divide asynchronously through schizogony, with only the final round of DNA replication and segregation being synchronous and coordinated with daughter cell assembly^2,3. However, the control mechanisms for this divergent mode of replication are unknown. Here we show that the Plasmodium-specific kinase PfCRK4 is a key cell cycle regulator that orchestrates the multiple rounds of DNA replication throughout schizogony in P. falciparum. PfCRK4 depletion led to a complete block in nuclear division and profoundly inhibited DNA replication. Quantitative phosphoproteomic profiling identified a set of PfCRK4-regulated phosphoproteins with greatest functional similarity to CDK2 substrates, particularly proteins involved in origin of replication firing. PfCRK4 was required for the initial and subsequent rounds of DNA replication during schizogony, and in addition was essential for development in the mosquito vector. Our results identified an essential S phase promoting factor of the unconventional P. falciparum cell cycle. PfCRK4 is required for both a prolonged period of the intraerythrocytic blood-stage of malaria infection, as well as for transmission, revealing a broad window for PfCRK4-targeted chemotherapeutics.

Molecular Markers of Radiation Induced Attenuation in Intrahepatic Plasmodium falciparum Parasites

Experimental immunization with radiation attenuated sporozoites (RAS) and genetically attenuated sporozoites has proved to be a promising approach for malaria vaccine development. However, parasite biomarkers of growth attenuation and enhanced immune protection in response to radiation remain poorly understood. Here, we report on the effect of an attenuating dose of γ-irradiation (15 krad) on the Plasmodium falciparum sporozoite (PfSPZ) ultrastructure by electron microscopy, growth rate of liver stage P. falciparum in liver cell cultures, and genome-wide transcriptional profile of liver stage parasites by microarray. We find that γ-irradiation treated PfSPZ retained a normal cellular structure except that they were vacuous with a partially disrupted plasma membrane and inner membrane complex. A similar infection rate was observed by γ-irradiation-treated and untreated PfSPZ in human HCO-4 liver cells (0.47% versus 0.49%, respectively) on day 3 post-infection. In the microarray studies, cumulatively, 180 liver stage parasite genes were significantly transcriptionally altered on day 3 and/or 6 post-infection. Among the transcriptionally altered biomarkers, we identified a signature of seven candidate parasite genes that associated with functionally diverse pathways that may regulate radiation induced cell cycle arrest of the parasite within the hepatocyte. A repertoire of 14 genes associated with protein translation is transcriptionally overexpressed within the parasite by radiation. Additionally, 37 genes encode proteins expressed on the cell surface or exported into the host cell, 4 encode membrane associated transporters, and 10 encode proteins related to misfolding and stress-related protein processing. These results have significantly increased the repertoire of novel targets for 1) biomarkers of safety to define proper attenuation, 2) generating genetically attenuated parasite vaccine candidates, and 3) subunit candidate vaccines against liver stage malaria.

Mutation Analysis in Chronic Myeloid Leukemia Patient in Chronic Phase on Imatinib Having Delayed Achievement of Milestones or Loss of Response

Tyrosine kinase inhibitors (TKI's) are currently the drug of choice for management of chronic myeloid leukemia. Imatinib is the most commonly used first line TKI in India. Mutations leading to resistance to imatinib are the most common cause for imatinib failure. We studied pattern of kinase domain mutations in 40 patients of CML who either lost their response or did not achieve it in defined timepoints. Loss of molecular response was the most common indication for asking mutation analysis. Sixteen patients were found to have detectable mutations. M351T was the most common tyrosine kinase mutation followed by Y253H and H396R. Two patients had 2 mutations simultaneously. M351T is the most common mutation in our patient population.

Haemostatic Profile in Patients of Myeloproliferative Neoplasms-A Tertiary Care Centre Experience

INTRODUCTION

Patients of MPN commonly present with abnormalities in laboratory coagulation tests that are consistent with hypercoagulable state. Some individuals with MPN exhibit a pattern of exclusive bleeding or thrombotic events; many others have both bleeding and thrombosis during the course of the disease.

AIM

This study was undertaken to assess the haemostatic defects and platelet functions in patients of MPN.

MATERIALS AND METHODS

One year prospective study was conducted at a tertiary care centre in North India in Department of Pathology in collaboration with Department of Clinical Haematology. All recently diagnosed cases of MPN along with 30 age and sex matched controls were included. Patients on antiplatelet drugs, antimyeloproliferative treatment, vitamin K agonists or antagonists, OCPs, Platelet count <1,00,000/μl, high grade fever, liver disease, pregnancy were excluded from this study. All the patients underwent screening investigations like CBC, peripheral smear evaluation, BT, PT, aPTT, Protein C and S measurement (clot based assay) and aggregation studies with ADP (5μM) (Optical Aggregometry with AGGRO/LINK 8 software and CHRONOLOG 700 aggregometer).

RESULTS

In present study, 50 cases were included. There was an occult prothrombotic state, suggested by significantly (p<0.001) reduced levels of Protein C and Protein S, but no patient presented with frank thrombosis while 8 out of 50 patients had haemorrhagic manifestations ranging from subdural haematoma to pin point petechial haemorrhages. Patients of CML-CP, ET, PV, PMF, MPN-NOS showed significantly reduced maximal aggregation with ADP (5μM) when compared to control (p<0.001). MPV also showed a statistically significant increase in these patients.

CONCLUSION

Thrombohaemorrhagic complications significantly affect the morbidity and mortality of MPN patients. This can be assessed by the use of platelet aggregation studies, Protein C and S activities and other coagulation studies. Timely diagnosis of these prothrombotic/haemorrhagic states can decrease the morbidity in these patients.

Effect of Mirtazapine Treatment on Serum Levels of Brain-Derived Neurotrophic Factor and Tumor Necrosis Factor-α in Patients of Major Depressive Disorder with Severe Depression

BACKGROUND

This study evaluated the clinical efficacy of mirtazapine and its effect on serum brain-derived neurotrophic factor (BDNF) and tumor necrosis factor-α (TNF-α) levels in patients of major-depressive disorder (MDD) with severe depression.

METHODS

Patients (aged 18-60) with MDD diagnosed by DSM-IV criteria, and Hamilton Rating Scale for Depression (HAM-D) score ≥25 were included (n = 30). Mirtazapine was given in the doses of 30 mg/day. All patients were followed up for 12 weeks for the evaluation of clinical efficacy, safety along with serum BDNF and TNF-α levels.

RESULTS

HAM-D score at the start of treatment was 30.1 ± 1.92, which significantly (p < 0.05) reduced to 13.47 ± 1.77 at 12 weeks of treatment. In responders, mean serum BDNF levels at the start of treatment were 2.32 ± 0.3 ng/ml, which significantly (p < 0.05) increased to 2.79 ± 0.33 ng/ml at 12 weeks of treatment and mean serum TNF-α levels at the start were 5.18 ± 0.67 pg/ml, which significantly decreased to 4.36 ± 0.72 pg/ml (p < 0.05) at 12 weeks of treatment.

CONCLUSION

Our results suggest that mirtazapine is effective and well tolerated in severely depressed patients and treatment response is associated with an increase in serum BDNF and a decrease in serum TNF-α levels.

Comparison of efficacy, safety and brain derived neurotrophic factor (BDNF) levels in patients of major depressive disorder, treated with fluoxetine and desvenlafaxine

This randomized, open label, prospective, observational study compared clinical efficacy, safety alongwith plasma BDNF levels in outpatients of depression treated with fluoxetine and desvenlafaxine. Patients (aged 18-60 years) with moderate to severe major depressive disorder (MDD) diagnosed by DSM-IV criteria, and Hamilton Rating Scale for Depression (HAM-D) score ≥14, who were prescribed fluoxetine or desvenlafaxine were included (n=30 in each group). Patients were followed up for 12 weeks for evaluation of clinical efficacy, safety along with BDNF levels. In the fluoxetine group, HAM-D scores at the start of treatment was 19±4.09 which significantly (p<0.05) reduced to 9.24±3.98 at 12 weeks. In the desvenlafaxine group, HAM-D scores at the start of treatment was 18±3.75 which significantly (p<0.05) reduced to 10±3.75 at 12 weeks. The BDNF levels in the fluoxetine group were 775.32±30.38pg/ml at the start of treatment which significantly (p<0.05) increased to 850.3±24.92pg/ml at 12 weeks. The BDNF levels in the desvenlafaxine group were 760.5±28.53pg/ml at the start of treatment which significantly (p<0.05) increased to 845.8±32.82pg/ml at 12 weeks. Both the antidepressants were found to be safe and well tolerated. The efficacy and the safety profile of desvenlafaxine is comparable to fluoxetine in patients of MDD. BDNF levels were significantly increased post-treatment with both the antidepressive agents. Whether BDNF may have a prognostic value in predicting treatment response to antidepressant drugs needs to be investigated in a larger patient population.

Antimalarial chemotherapy: orally curative artemisinin-derived trioxane dimer esters

Eight new artemisinin-derived trioxane dimer esters 5 have been prepared and tested for antimalarial efficacy in malaria-infected mice. At a single oral dose of only 6mg/kg combined with 18mg/kg of mefloquine, each of the dimer esters 5 outperformed the antimalarial drug artemether (2). The most efficacious dimer, dichlorobenzoate ester 5h, prolonged mouse survival past day 30 of infection with three of the four mice in this group having no detectable parasitemia and appearing and acting healthy on day 30.

A sensitive enhanced chemiluminescent-ELISA for the detection of Plasmodium falciparum circumsporozoite antigen in midguts of Anopheles stephensi mosquitoes

Efforts to develop a successful malaria vaccine are hampered due to lack of assays that are predictive of protective immunity without conducting large clinical studies. The effect of experimental vaccines and drugs on malaria transmission is yet more difficult to measure. Knowledge on the Plasmodium infection rate in mosquito populations will aid the measurement of effects from intervention measures for malaria control. Here, we report the development of a chemiluminescent sandwich ELISA (ECL-ELISA) that can detect Plasmodium falciparum circumsporozoite protein (Pf CSP) produced in recombinant form at concentrations of 4.4pg and in P. falciparum sporozoites (Pf SPZ) derived from mosquito salivary glands at levels corresponding to 5 Pf SPZ. Most importantly, we demonstrate reliable Pf CSP-based detection of 0.056day 8 P. falciparum oocysts developing inside mosquito midguts in whole mosquito lysates. Cumulatively, the ECL-ELISA is 47× more sensitive for the detection of Pf CSP than a colorimetric ELISA while greatly simplifying sample preparation, obviating the need for cumbersome midgut dissections and allowing high throughput screening of Plasmodium infection in mosquito populations. The ECL-ELISA may also have broader application in diagnosis of infectious diseases and the prognostic value in cancer and other diseases such as auto-immunity and genetic disorders based on antigen detection, or quality validation of biological vaccine components.

Gametocytocidal screen identifies novel chemical classes with Plasmodium falciparum transmission blocking activity

Discovery of transmission blocking compounds is an important intervention strategy necessary to eliminate and eradicate malaria. To date only a small number of drugs that inhibit gametocyte development and thereby transmission from the mosquito to the human host exist. This limitation is largely due to a lack of screening assays easily adaptable to high throughput because of multiple incubation steps or the requirement for high gametocytemia. Here we report the discovery of new compounds with gametocytocidal activity using a simple and robust SYBR Green I- based DNA assay. Our assay utilizes the exflagellation step in male gametocytes and a background suppressor, which masks the staining of dead cells to achieve healthy signal to noise ratio by increasing signal of viable parasites and subtracting signal from dead parasites. By determining the contribution of exflagellation to fluorescent signal and using appropriate cutoff values, we were able to screen for gametocytocidal compounds. After assay validation and optimization, we screened an FDA approved drug library of approximately 1500 compounds, as well as the 400 compound MMV malaria box and identified 44 gametocytocidal compounds with sub to low micromolar IC₅₀s. Major classes of compounds with gametocytocidal activity included quaternary ammonium compounds with structural similarity to choline, acridine-like compounds similar to quinacrine and pyronaridine, as well as antidepressant, antineoplastic, and anthelminthic compounds. Top drug candidates showed near complete transmission blocking in membrane feeding assays. This assay is simple, reproducible and demonstrated robust Z-factor values at low gametocytemia levels, making it amenable to HTS for identification of novel and potent gametocytocidal compounds.

Model system to define pharmacokinetic requirements for antimalarial drug efficacy

Malaria presents a tremendous public health burden, and new therapies are needed. Massive compound libraries screened against Plasmodium falciparum have yielded thousands of lead compounds, resulting in an acute need for rational criteria to select the best candidates for development. We reasoned that, akin to antibacterials, antimalarials might have an essential pharmacokinetic requirement for efficacy: action governed either by total exposure or peak concentration (AUC/CMAX), or by duration above a defined minimum concentration [time above minimum inhibitory concentration (TMIC)]. We devised an in vitro system for P. falciparum, capable of mimicking the dynamic fluctuations of a drug in vivo. Using this apparatus, we find that chloroquine is TMIC-dependent, whereas the efficacy of artemisinin is driven by CMAX. The latter was confirmed in a mouse model of malaria. These characteristics can explain the clinical success of two antimalarial drugs with widely different kinetics in humans. Chloroquine, which persists for weeks, is ideally suited for its TMIC mechanism, whereas great efficacy despite short exposure (t1/2 in blood 3 hours or less) is attained by CMAX-driven artemisinins. This validated preclinical model system can be used to select those antimalarial lead compounds whose CMAX or TMIC requirement for efficacy matches pharmacokinetics obtained in vivo. The apparatus can also be used to explore the kinetic dependence of other pharmacodynamic endpoints in parasites.

Antimalarial chemotherapy: artemisinin-derived dimer carbonates and thiocarbonates

Several 2-carbon-linked trioxane dimer secondary alcohol carbonates 14 and thiocarbonates 15, combined with mefloquine and administered in a low single oral dose, prolonged the survival times of malaria-infected mice much more effectively than the popular monomeric antimalarial drug artemether plus mefloquine. Three dimer carbonates 14 and one dimer thiocarbonate 15 partially cured malaria-infected mice.

The survival times of malaria-infected mice are prolonged more by several new two-carbon-linked artemisinin-derived dimer carbamates than by the trioxane antimalarial drug artemether

Sixteen new artemisinin-derived 2-carbon-linked trioxane dimers were prepared to study chemical structure/antimalarial activity relationships (SAR). Administering a very low single oral dose of only 5mg/kg of dimer secondary alcohol 6a or 6b plus 15 mg/kg of mefloquine hydrochloride prolonged the lives of Plasmodium berghei-infected mice to an average of 25 days after infection. This ACT chemotherapy result is of high medicinal significance because the antimalarial efficacy of the popular trioxane drug artemether (2) plus mefloquine under the same conditions was significantly lower (only 20 day average survival). NH-aryl carbamate derivatives 7e, 7i, and 7j of 2-carbon-linked dimer alcohol 6b also significantly outperformed artemether (2) in prolonging the survival times (25-27 days) of malaria-infected mice.

Study of rumen metagenome community using qPCR under different diets

The aim of this study was to detect the major bacteria present in rumen microbiota. Here, we performed qPCR based absolute quantitation of selected rumen microbes in rumen fluid of river buffalo adapted to varying proportion of concentrate to roughage diets. Animals were adapted to roughage-to-concentrate ratio in the proportion of 100:00 (T1), 75:25 (T2), 50:50 (T3) and 25:75 (T4) respectively for 30 days. At the end of each treatment, rumen fluid was collected at 0 h and 2 h after feeding. It was found that among fibrolytic bacteria Ruminococcus flavefaciens (2.22 × 10(8) copies/ml) were highest in T2 group and followed by 1.11 × 10(8) copies/ml for Fibrobacter succinogenes (T2), 2.56 × 10(7) copies/ml for Prevotella ruminicola (T1) and 1.25 × 10(7) copies/ml for Ruminococcus albus (T4). In non-fibrolytic bacteria, the Selenomonas ruminantium (2.62 × 10(7) copies/ml) was predominant in group T3 and followed by Treponema bryantii (2.52 × 10(7)copies/ml) in group T1, Ruminobacter amylophilus (1.31 × 10(7)copies/ml) in group T1 and Anaerovibrio lipolytica (2.58 × 10(6) copies/ml) in group T4. It is most notable that R. flavefaciens were the highest in population in the rumen of Surti buffalo fed wheat straw as roughage source.

Genetic polymorphisms in Cytochrome P 4501B1 and susceptibility to idiopathic preterm labor in North Indian population

OBJECTIVE

The etiology of preterm labor (PTL) is still unknown, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We investigated the relation between PTL and polymorphisms in Cytochrome P4501B1 (CYP1B1) gene, which is involved in the metabolism of a wide range of environmental toxins and hormones.

DESIGN AND METHODS

Three hundred (n=300) cases of PTL and equal number of subjects of full term labor (FTL), after excluding all the known risk factors for PTL were included in the study. A two step allele specific PCR was performed for polymorphic analysis of CYP1B1 gene.

RESULTS

The homozygous variant genotype of CYP1B1*2 (OR=2.97, 95%CI=1.08-8.08, p=0.033) and heterozygous variant of CYP1B1*3 (OR=2.57, 95%CI=1.88-3.63, p=0.001), and CYP1B1*7 (OR=2.59, 95%CI=1.85-3.62, p=0.001) were found to be significantly higher in PTL cases as compared to FTL.

CONCLUSIONS

The present study demonstrates the possible association of homozygous variant of CYP1B1*2 and heterozygous variant of CYP1B1*3 and CYP1B1*7 genes with the increased risk of PTL.

Characterization of smallholder pig production system: productive and reproductive performances of local and crossbred pigs in Sikkim Himalayan region

The present study was conducted to know the smallholder pig production system in tribal areas of Sikkim State, India. Two hundred tribal farmers were selected randomly from the North and East District of the state. Information on socio-economic characteristics of farmers (gender, occupation, educational status, and farming experience), management practices, disease prevalence, and economics in pig production was collected. The study recorded the mean land holding as 1.2 ± 0.8 ha, and the number of pigs per farm was 5.0 ± 0.28. Pigs were mainly kept as a source of income, and 70 % of farmers reared crossbreed pigs. Ninety percent (90 %) of respondents practiced the intensive system of management whereby kitchen wastes along with cooked mixture comprising maize bhusa, mustard oil cake, pseudostem of banana, tuber, stem, and plant leaves were used to feed their animals. About 40.5 % of farmers procured their breeding stock from government farms that had good records and utilized veterinary services like timely vaccination and deworming. The diseases prevalent in the study area were swine fever, diarrhea, helminthoses, sarcoptic mange, pneumonia, etc. The litter sizes at birth (local, 4.3 ± 0.45; crossbreed, 7.2 ± 0.33), at weaning (local, 2.79 ± 0.24; crossbreed, 6.1 ± 0.21), and age at first farrowing (local, 365.39 ± 7.96 days; crossbreed, 337.24 ± 8.79 days) were recorded. Production costs of meat extracted from local and crossbred pigs were 1.08 $/kg and 0.86 $/kg, respectively.

Primary T-cell lymphoma of liver

Primary hepatic lymphoma (PHL) is rare and represents approximately 0.016% of all cases of non-Hodgkin's lymphoma (NHL). The majority of these are B-cell NHL of diffuse large B-cell type. Primary T-cell lymphoma constitutes approximately 5-10% of all PHLs arising in the liver, 90% being B-cell type. Peripheral T-cell lymphoma, γδ hepatosplenic T-cell lymphoma and αβ hepatosplenic T-cell lymphoma are the common T-cell lymphomas involving hepatic parenchyma. We encountered a case presenting with gross hepatomegaly extending beyond umbilicus, mild ascites, pedal oedema, icterus and dyspnoea. Haemogram showed moderate anaemia with counts. Bone marrow aspiration showed erythroid hyperplasia with dimorphic anaemia. There was no evidence of atypical lymphoid cells in peripheral blood of bone marrow. We present a rare case of primary T-cell lymphoma presenting as primary liver involvement without splenomegaly, lymphadenopathy, bone marrow or peripheral blood involvement.

Experimental evaluation of antidepressant effect of Vacha (Acorus calamus) in animal models of depression

Depression is a common diagnosis throughout India. It is one of the major sequelae of modern lifestyle which is full of stress. Several drugs and therapies have been tried but a safe and effective treatment of depressive illness is yet not fully established. The main objective of this experimental study on animal models is to evaluate the antidepressant action of plant drug Vacha (Acorus calamus). The behavioral study was conducted and at the same time 5-HT receptor involvement was evaluated. The experimental study was done in rats to evaluate their Open Field Behavior (OFB), High Plus Maze (HPM) activity and 5-hydroxytryptamine (5-HT) receptor syndrome, before and after feeding Vacha. Concurrent Vacha administration in the depression model prevented the development of behavioral deficit in ambulation and rearing due to stress. Similarly, in High Plus Maze Test (HPMT), exploratory activity of rat was restored with Vacha administration. In adopted model of depression, when the animal was subjected to Vacha administration, the behavioural deficit was prevented very well as compared to stressed group. While eliciting the 5-HT syndrome, only two components out of five were influenced by Vacha, indicating that Vacha does not sensitize postsynaptic 5-HT1A receptors, which explains the behavioral deficit prevention in stressed rat group. Vacha definitely has antidepressant effects in animal model of depression.

Malaria-infected mice live until at least day 30 after a new artemisinin-derived thioacetal thiocarbonate combined with mefloquine are administered together in a single, low, oral dose

In only three steps and in 21-67% overall yields from the natural trioxane artemisinin, a series of 21 new trioxane C-10 thioacetals was prepared. Upon receiving a single oral dose of only 6 mg/kg of the monomeric trioxane 12c combined with 18 mg/kg of mefloquine hydrochloride, Plasmodium berghei-infected mice survived on average 29.8 days after infection. Two of the four mice in this group had no parasites detectable in their blood on day 30 after infection, and they behaved normally and appeared healthy. One of the mice had 11% blood parasitemia on day 30, and one mouse in this group died on day 29. Of high medicinal importance, the efficacy of this ACT chemotherapy is much better than (almost double) the efficacy under the same conditions using as a positive control the popular trioxane drug artemether plus mefloquine hydrochloride (average survival time of only 16.5 days).

Balancing efficacy and bleeding risk in the prevention of stroke due to atrial fibrillation with newer oral anticoagulants

With the evaluation and approval of newer oral anticoagulants such as the factor IIa inhibitor, dabigatran etexilate and the factor Xa inhibitors, rivaroxaban and apixaban, strategies for stroke prevention in atrial fibrillation need a thorough re-evaluation of current options. Clinicians are naturally excited about the imminent introduction of these newer drugs that do not need international normalized ratio (INR) monitoring, besides having no drug-food and minimal drug-drug interactions. However, as with all new drugs, it is always prudent to use these judiciously so that they stay in our therapeutic armamentarium for a long time. More than 56 years after the introduction of warfarin we now have three drugs, viz., dabigatran 150 mg bid, rivaroxaban 20 mg od, and apixaban 5 mg bid which were effective in comparison with warfarin in reducing the risk of stroke and bleeding in the landmark trials, RE-LY, ROCKET-AF, and ARISTOTLE respectively. There is a thin dividing line between physiological hemostasis and pathological thrombosis. Routine INR monitoring may not be required but in special situations, such as prior to major surgery, overdose, non-compliance or stroke while on the anticoagulant, one may wish to know whether there are any laboratory measures of efficacy or means of reversal of over anticoagulation. Similar questions may be raised about other situations such as renal dysfunction, cardioversion, ablation procedures, post-stenting, or switch to and from warfarin, heparin or LMWH? This document is an attempt to address these concerns based on available evidence and give physicians a perspective and practice guidelines on how best to use these agents, both old and new, for optimal patient outcomes, maximizing efficacy and minimizing risk.

Targeting strategies for Human immunodeficiency virus: a combinatorial approach

The battle between human and the Human immunodeficiency virus (HIV) is on, with both of them rapidly improving their attacking and defense strategies. Many therapeutic agents for HIV infection have been designed and developed, However there are various aspects, like novel targets against HIV, which are yet to be unfolded with a goal of designing and developing novel drug molecules against HIV. This article reviews the current status and innovative new options for antiretroviral therapy for HIV and also discusses the various mechanisms of action for each class of drugs, and the problems yet to be solved with respect to HIV as a target for improvised treatment against AIDS.

Development and characterization of cell culture systems from Puntius (Tor) chelynoides (McClelland)

Puntius (Tor) chelynoides, commonly known as dark mahseer, is a commercially important coldwater fish species which inhabits fast-flowing hill-streams of India and Nepal. Cell culture systems were developed from eye, fin, heart and swim bladder tissues of P. chelynoides using explant method. The cell culture system developed from eye has been maintained towards a continuous cell line designated as PCE. The cells were grown in 25cm(2) tissue culture flasks with Leibovitz' L-15 media supplemented with 20 % fetal bovine serum (FBS) at 24°C. The PCE cell line consists of predominantly fibroblast-like cells and showed high plating efficiency. The monolayer formed from the fin and heart explants were comprised of epithelial as well as fibroblast-like cells, a prominent and rhythmic heartbeat was also observed in heart explants. Monolayer formed from swim bladder explants showed the morphology of fibroblast-like cells. All the cells from different tissues are able to grow at an optimum temperature of 24°C and growth rate increased as the FBS concentration increased. The PCE cell line was characterized using amplification of mitochondrial cytochrome oxidase subunit I (COI) & 16S rRNA genes which confirmed that the cell line originated from P. chelynoides. Cytogenetic analysis of PCE cell line and cells from fin revealed a diploid count of 100 chromosomes. Upon transfection with pEGFP-C1 plasmid, bright fluorescent signals were observed, suggesting that this cell line can be used for transgenic and genetic manipulation studies. Further, genotoxicity assessment of PCE cells illustrated the utility of this cell line as an in vitro model for aquatic toxicological studies. The PCE cell line was successfully cryopreserved and revived at different passage levels. The cell line and culture systems are being maintained to develop continuous cell lines for further studies.

Prevalence and characterization of thrombocytopenia in pregnancy in Indian women

To find the prevalence and causes of thrombocytopenia during pregnancy. An analytical prospective observational study was conducted in Department of Obstetrics & Gynecology, CSMMU, Lucknow. 1079 antenatal women screened for thrombocytopenia and investigated for cause and management strategies and fetomaternal outcome were recorded. Prevalence of thrombocytopenia was 8.8%. Gestational thrombocytopenia was seen in 64.2%, obstetric in 22.1% and medical in 13.68% cases. Mean platelet count in controls was lower with a significant fall (P < 0.001) in the platelet count as pregnancy advanced. Hypertensive and hepatic disorders were the most common obstetric causes of thrombocytopenia. Mode of delivery was not affected by thrombocytopenia. Maternal morbidity and mortality was seen only in medical and obstetric thrombocytopenia. The low platelet counts and declining trend with increasing gestational age predispose Indian women to risk of thrombocytopenia and a routine platelet count is suggested.

Effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in mice exposed to cocaine

OBJECTIVE

To investigate the effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in experimental animals exposed to cocaine.

MATERIALS AND METHODS

Mice were used in this study and were divided randomly into different groups of six animals each. They were either treated with intraperitoneal injection of saline or cocaine hydrochloride or an oral feeding of oil of Ocimum sanctum, ascorbic acid or verapamil, or both (ascorbic acid and verapamil), and were evaluated for a respiratory burst of macrophages, superoxide and nitric oxide (NO) production, estimation of TNF-alpha in the serum and supernatant of cultured macrophages, estimation of lipid peroxidation (malondialdehyde- MDA) in the serum, and superoxide dismutase activity in the erythrocytes.

RESULTS

Unstimulated respiratory burst as well as superoxide production was enhanced on treatment with cocaine and all the three drugs were found to attenuate this enhancement. The bactericidal capacity of macrophages decreased significantly on chronic cocaine exposure, as it was associated with decreased respiratory burst and superoxide production. There was a significant decrease in NO production by macrophages on chronic cocaine exposure and all the test drugs were found to restore nitrite formation to a normal level. There was an increase in the malonylodialdehyde (MDA) level and decrease in the superoxide dismutase level on chronic cocaine exposure, and all the three drugs effectively decreased the MDA level and increased superoxide dismutase level. There was an increase in serum TNF-alpha on chronic cocaine exposure, which was decreased significantly by ascorbic acid and verapamil.

CONCLUSION

O. sanctum, ascorbic acid, and verapamil were equally effective in improving the macrophage function and reducing oxidative stress. These findings suggested that O. sanctum, ascorbic acid, and verapamil attenuated acute and chronic cocaine-mediated effects.

Methanogen diversity in the rumen of Indian Surti buffalo (Bubalus bubalis), assessed by 16S rDNA analysis

The methanogenic communities in buffalo rumen were characterized using a culture-independent approach of a pooled sample of rumen fluid from three adult Surti buffaloes. Buffalo rumen is likely to include species of various methanogens, so 16S rDNA sequences were amplified and cloned from the sample. A total of 171 clones were sequenced to examine 16S rDNA sequence similarity. About 52.63% sequences (90 clones) had ≥ 90% similarity, whereas, 46.78% of the sequences (81 clones) were 75-89% similar to 16S rDNA database sequences, respectively. Phylogenetic analyses were also used to infer the makeup of methanogenic communities in the rumen of Surti buffalo. As a result, we distinguished 23 operational taxonomic units (OTUs) based on unique 16S rDNA sequences: 12 OTUs (52.17%) affiliated to Methanomicrobiales order, 10 OTUs (43.47%) of the order Methanobacteriales and one OTU (4.34%) of Methanosarcina barkeri like clone, respectively. In addition, the population of Methanomicrobiales and Methabacteriales orders were also observed, accounting 4% and 2.17% of total archea. This study has revealed the largest assortment of hydrogenotrophic methanogens phylotypes ever identified from rumen of Surti buffaloes.

An atypical case of dengue haemorrhagic fever presenting as quadriparesis due to compressive myelopathy

Dengue haemorrhagic fever is a serious presentation of dengue viral infection. Case reports of cerebral haemorrhage due to dengue are rare. The authors report a rare case of dengue haemorrhagic fever presenting with fever and acute onset progressive quadriparesis of the upper motor neuron type. Rare cases of quadriparesis in dengue fever have been reported in the literature due to myositis, Guillain-Barre syndrome, myelitis and hypokalaemia. This case on investigations was found to have extramedullary compression due to haematoma in the cervical region as the cause of quadriparesis.

Bacterial diversity in the rumen of Indian Surti buffalo (Bubalus bubalis), assessed by 16S rDNA analysis

Bacterial communities in buffalo rumen were characterized using a culture-independent approach for a pooled sample of rumen fluid from 3 adult Surti buffaloes. Buffalo rumen is likely to include species of various bacterial phyla, so 16S rDNA sequences were amplified and cloned from the sample. A total of 191 clones were sequenced and similarities to known 16S rDNA sequences were examined. About 62.82% sequences (120 clones) had >90% similarity to the 16S rDNA database sequences. Furthermore, about 34.03% of the sequences (65 clones) were 85-89% similar to 16S rDNA database sequences. For the remaining 3.14%; the similarity was lower than 85% Phylogenetic analyses were also used to infer the makeup of bacterial communities in the rumen of Surti buffalo. As a result, we distinguished 42 operational taxonomic units (OTUs) based on unique 16S r DNA sequences: 19 OTUs affiliated to an unidentified group (45.23% of total OTUs), 11 OTUs of the phylum Firmicutes, also known as the low G+C group (26.19%), 7 OTUs of the Cytophaga-Flexibacter-Bacteroides phylum (16.66%), 4 OTUs of Spirochaetes (9.52%), and 1 OTU of Actinobacteria (2.38%). These include 10 single-clone OTUs, so Good's coverage (94.76%) of 16S rRNA libraries indicated that sequences identified in the libraries represent the majority of bacterial diversity present in rumen.

Profile of CD4 counts and symptoms in HIV positive patients on and not on antiretroviral therapy

This communication pertains to a study on analysis of the profile of CD4 counts and symptoms in HIV infected adult subjects on and not on antiretroviral therapy. Clinical symptoms in HIV infected patients attending a tertiary care hospital in north India were recorded by direct questioning. Differences in distribution of categorical variables were analyzed using chi-square test. A p-value < 0.05 was considered statistically significant. 317 enrolled HIV positive patients, 271/317 (85.5%) patients were symptomatic. The common symptoms were weakness (65.6%), bodyache and joint pain (63.4%), lethargy and fatigue (62.5%), prolonged fever (53.3%), weight loss (47.6%), cough (44.5%), loss of appetite (44.2%) and chronic diarrhoea (40.1%). Most symptoms were found significantly less frequently in patients on antiretroviral therapy (ART). High CD4+ T-cell counts were negatively associated with symptoms. The overall proportion of symptomatic patients was significantly higher than the number with an etiologically documented opportunistic infections (32.5%). Pulmonary tuberculosis (30.9%) was the most frequently documented opportunistic infection. Antiretroviral therapy appears to be beneficial in reducing symptoms in HIV positive patients. Affordable high quality laboratory diagnostic facilities for the diagnosis of opportunistic infections under the public health program will help to obtain an accurate picture of the range of opportunistic infections in HIV patients in India.

Total Leukocyte Counts and the Requirement of Dose Reduction due to Cytopenias as Prognostic Indicators Affecting Response to Imatinib in Chronic Myeloid Leukemia

Imatinib is a tyrosine kinase inhibitor and is considered the first line of non stem cell transplantation treatment for patients diagnosed with CML. We evaluated the response rates and adverse reactions to Imatinib in our patients and tried to identify factors which affected the response to Imatinib. Eighty-four patients were diagnosed on the basis of clinical and haematological variables with confirmation by FISH, detecting Philadelphia chromosome or bcr-abl translocation and were then started on oral capsule Imatinib. A complete haematological response was seen in 78.04% patients, while complete cytogenetic response (CCR) was seen in 12.2% of patients and major cytogenetic response (MCR) was seen in 64.63% of patients. It was found that that a greater total leukocyte count (TLC) on presentation had a negative correlation with cytogenetic response. Cytopenias were seen in 36 patients (43.82%). 34.9% of patients having CCR/MCR required dose reduction while 73.6% of patients not achieving CCR/MCR required dose reduction. This was a significant difference, confirmed on statistical analysis (P < 0.05; P = 0.019), establishing the negative prognostic value of dose reduction due to cytopenias.