An oxo(corrolato)chromium(V) complex selectively kills cancer cells by inducing DNA damage.

An oxo(corrolato)chromium(v) complex selectively kills leukemia cells. However, this complex did not induce cell death in primary non-cancer cells. It has been observed that oxo(corrolato)chromium(v) complex induced cell death is associated with DNA damage. Interestingly, the DNA in primary cells largely remained unaffected. DNA isolated from normal and cancerous cell lines also follows similar trends. A chemical reductant, DTT, was used to probe the mechanism of DNA damage. However, it does not show any additive effect on DNA damage.

Prevalence and transmission potential of Wolbachia in Aedes albopictus population circulating in endemic coastal districts of Odisha, India.

Wolbachia, known for its reproductive manipulation capabilities in insects, are being implemented to control dengue and chikungunya. To understand Wolbachia biology and its utility as a bio-control for vector mosquito's populations, we investigated its dissemination pattern in field in collected Ae. albopictus along with its maternal transmission efficacy over generations in regions of endemic dengue (DENV) transmission. Field collected Ae. albopictus were subjected to PCR for Wolbachia screening. Overall mean Wolbachia infection frequency in Ae. albopictus was found out to be 87.3% wherein a trend was observed in the pattern of maternal transmission across generations. χ2 for trend revealed a significant variation between Wolbachia infections and non-infections in Ae. albopictus generations. Linear regression analysis revealed the involvement of a strong negative correlation, implying that overall Wolbachia infection tends to decrease in places with high dengue cases.The reduction in Wolbachia infection frequency may be attributed to several environmental factors with the probability of being the cause for endemicity of dengue in the studied areas.This study reports on the transmission efficacy of naturally occurring Wolbachia in successive generations of Ae. albopictus and its correlation with dengue cases in clusters of Odisha, India. Studying the transmission trend of Wolbachia along with transovarial transmission of DENV might be indicative towards the interplay of Wolbachia infection in presence/absence of DENV.

Implementation of molecular method in routine malaria diagnosis and entomological studies.

BACKGROUND & OBJECTIVES: Molecular methods for malaria vector species and parasite identification have received great attention in recent years. Accurate and precise identification of the target species has direct medical and practical implications, such as in malaria diagnosis and vector dynamics study. Translation of molecular techniques will help in evaluation of epidemiological and entomological profile of malaria even in highly inaccessible areas where there is lack of an expert microscopist or entomologist. METHODS: In the present study, we have developed a simple yet accurate molecular tool for malaria diagnosis as well as for malaria vector studies. We have standardized, simplified and improvised the DNA isolation (using Chelex; a cationic exchanger), its storage and multiplex PCR for parasite detection from dried blood spot (DBS) filter paper as well as malaria vector identification and infection status study. RESULTS: The chelex-PCR based molecular method was highly sensitive (sensitivity >90%) and specific (specificity >80%) for parasite detection as well as vector species identification. This method has proven readily adaptable for use in the clinical diagnostic/research laboratory for epidemiological investigation and vector dynamics study that can challenge the conventional gold standard approach such as microscopy/ morphological methods not only in response to accuracy but also in relation to cost, time and technical expertise. INTERPRETATION & CONCLUSION: Transfer of this molecular technology from laboratory to field condition is highly essential for its availability to the common public rather than being restricted to only academic research. This can be achieved by implementation of the technology in terms of conducting mass training and awareness programs in various resource-limited endemic zones for the purpose of malaria elimination.

Vector dynamics predicts transmission dynamics: a simple, realistic and sensible approach for measuring malaria endemicity.

Entomological indicators such as vector density, distribution, biology and bionomics and their vectorial attributes are important parameters for measuring the pattern and intensity of malaria transmission. Although published articles provide evidence for the existence of associations between entomological indices and malaria transmission dynamics, none of them is able to establish a strong correlation. In order to address this issue, the present study aims to assess how malaria transmission is influenced and can be predicted by local major vector dynamics. We carried out an entomological assessment of major Anopheline vector abundance, habit/habitat, resting and feeding behavior, infectivity rates, and other entomological parameters. Results suggest that malaria transmission was correlated with a vector control intervention and non-intervention scenario in a high endemic region of Kalahandi district of Odisha, India. Amongst all indices, infective anthropophagic vectors established a strong positive correlation with malaria morbidity in comparison to infective or anthropophagic vector species during both the study periods. Though other entomological parameters influenced the transmission intensity, little quantifiable association was detected among study sites. This study provides strong baseline evidence of an association between entomological indices and malaria transmission dynamics, which could be used as an early warning system for outbreak prediction.

Wolbachia Population in Vectors and Non-vectors: A Sustainable Approach Towards Dengue Control.

Wolbachia is gram negative obligate endosymbiont known for reproductive manipulation in the host. It is important to study the presence of natural Wolbachia in mosquitoes which can later help in understanding the effect of transfected strain on indigenous strain. With this view, the present study is undertaken to focus on the prevalence, diversity, infection frequencies, phylogeny and density of indigenous Wolbachia strains in wild mosquito species of Odisha. Our study confirms Wolbachia presence in Ae. albopictus, Cx. quinquefasciatus, Cx. vishnui, Cx. gelidus, Ar. subalbatus, Mn. uniformis, and Mn. indiana. Wolbachia in the above mosquitoes were separated into two supergroups (A and B). Ae. albopictus, the major vector of dengue and chikungungunya had both super-infection and mono-infection. The ovaries of Ae. albopictus were highest in density of Wolbachia as compared to midguts or salivary glands. wAlBA and wAlbB density were variable in mosquitoes of F1 generation for both the sex and at different age. We also found that Wolbachia super-infection in females tends to increase whereas wAlbA density reduced completely as compared to wAlbB in males when they grew old. Giemsa stained squashed ovaries revealed pink pleomorphic Wolbachia cells with different shapes and forms. This study is unique in its kind covering the major aspects of the endosymbiont Wolbachia and focusing on its potential as a biocontrol agent in arboviral outbreaks. Knowledge on potential of the indigenous strain and interactions between Wolbachia and viruses can be utilized further to reduce the global burden of vector borne diseases.

Comparative analysis of three methods from dried blood spots for expeditious DNA extraction from mosquitoes; suitable for PCR based techniques.

The objective of this work was to compare the quality, purity and quantity of DNA isolated from dried blood spots (DBS) by three methods (Chelex-100, QIAamp DNA mini kit, and TE (Tris EDTA)-Buffer). Sample collection was performed in six districts in Odisha, India and screened for cases of clinical malaria and dengue and vector density. Mosquito abdomens were spotted on Whatman 3MM (MERCK) Filter paper and dried for 10 min at room temperature. DNA was isolated from DBS using three methods (Chelex-100, QIAamp DNA mini kit, and TE-Buffer), and PCR was used to determine the feeding behaviours of vector mosquitoes. DNA was quantified using a UV-spectrophotometer, and q-PCR was used to determine the target gene copy number to compare the methods. The QIAamp DNA mini kit method was used as the reference method. The yield and purity of DNA extracted with Chelex-100 and TE were 14-72 ng/µl and 1.51-1.85 and 9-50 ng/µl and 1.68-2.1, respectively. DNA extracted using the Chelex-100 method was stored for over 1 month at - 20 °C and was suitable for later use. The Chelex-100 method had a sensitivity of 99.5% and specificity of 78%. A Bland-Altman plot suggested that the Chelex-100 method was similar to the QIAamp DNA mini kit method for determining the feeding behaviours of vector mosquitoes. The Chelex-100 method is simple, cost-effective, and safe and requires minimal time for DNA extraction from dried blood spots. In malaria and dengue research, detecting the feeding behaviours from mosquito DNA from dried blood spots on filter paper by PCR is an easy, minimally invasive and inexpensive molecular technique that can be performed in remote areas.

Can a non-invasive urine-based test become the next-generation diagnostic tool for malaria?

This mini review summarises the non-invasive urine-based diagnostic approaches that have been used to diagnose malaria. Amongst all urine-based diagnosis methods, commercially available Rapid Diagnostic kit/strip is most likely to be suitable for malaria detection in a cost-effective, time-consuming and user-friendly manner. With further improvement in sensitivity, specificity and accuracy, this technique may become a useful next-generation gold standard malaria diagnostic tool in resource-limited regions and in areas where invasive blood tests are restricted.

Epidemiological profile of malaria among various socio-demographic groups in a western district of Odisha, India.

A retrospective analysis of malaria incidence, patterns and trends in Bargarh, a western district of Odisha, India, over five consecutive years (2012 to 2016) among various socio-demographic components was established from the National Vector Borne Disease Control Programme (NVBDCP), Bargarh, as well as from district survey reports. The increasing trend in malariometric indices such as the Annual Blood Examination Rate (ABER), the Annual Parasite index (API) as well as the Total Positive Rate (TPR) reveals a better surveillance activity but an alarming situation for malaria. The trend for P. falciparum and P. vivax infection is found to be zigzagging or fluctuating for the five years in question, with the preponderance of P. falciparum infection. Malaria in Bargarh district is age-specific where there is a strong positive correlation between the age factor and malaria morbidity, but it is gender-blind. The incidence of malaria is increasing among deprived communities as well as pregnant women in the district. The community perception study reveals the knowledge level regarding cause, prevention and treatment for malaria, which is lower among deprived communities than more progressive communities. The overall epidemiological study highlights the dynamics of disease transmission among various demographic members in Bargarh district, whilst evaluating awareness of current malaria endemicity.

Induction of apoptosis by Fe(salen)Cl through caspase-dependent pathway specifically in tumor cells.

Iron-based compounds possess the capability of inducing cell death due to their reactivity with oxidant molecules, but their specificity towards cancer cells and the mechanism of action are hitherto less investigated. A Fe(salen)Cl derivative has been synthesized that remains active in monomer form. The efficacy of this compound as an anti-tumor agent has been investigated in mouse and human leukemia cell lines. Fe(salen)Cl induces cell death specifically in tumor cells and not in primary cells. Mouse and human T-cell leukemia cell lines, EL4 and Jurkat cells are found to be susceptible to Fe(salen)Cl and undergo apoptosis, but normal mouse spleen cells and human peripheral blood mononuclear cells (PBMC) remain largely unaffected by Fe(salen)Cl. Fe(salen)Cl treated tumor cells show significantly higher expression level of cytochrome c that might have triggered the cascade of reactions leading to apoptosis in cancer cells. A significant loss of mitochondrial membrane potential upon Fe(salen)Cl treatment suggests that Fe(salen)Cl induces apoptosis by disrupting mitochondrial membrane potential and homeostasis, leading to cytotoxity. We also established that apoptosis in the Fe(salen)Cl-treated tumor cells is mediated through caspase-dependent pathway. This is the first report demonstrating that Fe(salen)Cl can specifically target the tumor cells, leaving the primary cells least affected, indicating an excellent potential for this compound to emerge as a next-generation anti-tumor drug.