Protein kinase PfPK2 mediated signalling is critical for host erythrocyte invasion by malaria parasite.

Signalling pathways in malaria parasite remain poorly defined and major reason for this is the lack of understanding of the function of majority of parasite protein kinases and phosphatases in parasite signalling and its biology. In the present study, we have elucidated the function of Protein Kinase 2 (PfPK2), which is known to be indispensable for the survival of human malaria parasite Plasmodium falciparum. We demonstrate that it is involved in the invasion of host erythrocytes, which is critical for establishing infection. In addition, PfPK2 may also be involved in the maturation of the parasite post-invasion. PfPK2 regulates the release of microneme proteins like Apical Membrane Antigen 1 (AMA1), which facilitates the formation of Tight Junction between the merozoite and host erythrocyte- a key step in the process of invasion. Comparative phosphoproteomics studies revealed that PfPK2 may be involved in regulation of several key proteins involved in invasion and signalling. Furthermore, PfPK2 regulates the generation of cGMP and the release of calcium in the parasite, which are key second messengers for the process of invasion. These and other studies have shed light on a novel signalling pathway in which PfPK2 acts as an upstream regulator of important cGMP-calcium signalling, which plays an important role in parasite invasion.

Seroprevalence & changing trends of transfusion-transmitted infections amongst blood donors in a Regional Blood Transfusion Centre in north India.

Background & objectives: Transfusion-transmitted infections (TTIs) are the major problem associated with blood transfusion. Accurate estimates of risk of TTIs are essential for monitoring the safety of blood supply. The present study was undertaken to determine the percentage of voluntary donors (VDs) and replacement donors (RDs) and also, to estimate and compare the seroprevalence and changing trends of TTIs amongst VDs and RDs in a regional blood transfusion centre in north India. Methods: This retrospective study was based on the records of all voluntary and replacement donations which were collected from January 2008 to December 2014 in a Regional Blood Transfusion Centre placed in a tertiary care hospital in Delhi, India. Results: Of the total 220,482 donations, 163,540 (74.17%) were voluntary and 56,942 (25.83%) were replacement donation. The overall seroprevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), syphilis and malaria were 0.32, 1.61, 0.73, 1.62 and 0.06 per cent, respectively. Furthermore, the TTIs were more frequently encountered in RDs in comparison to VDs. Interpretation & conclusions: The increase in public awareness regarding voluntary blood donation, meticulous donor screening, counselling and use of highly sensitive tests can help in reducing the risk of TTIs.

Lupus anticoagulants and anticardiolipin antibodies in Indian women with spontaneous, recurrent fetal loss.

Spontaneous and recurrent pregnancy loss are common complications of pregnancy resulting from varied causes including antiphospholipid syndrome (APS). Treatment of women with APS increases the chance of a subsequent successful pregnancy. The study aimed to find the prevalence of lupus anticoagulants (LA) and anticardiolipin antibodies (ACAs) in women with spontaneous/recurrent fetal loss and compare with women with normal obstetric history. Hundred women with spontaneous/recurrent fetal loss and 50 healthy pregnant controls were tested for LA by complete blood counts, Prothrombin time, Activated partial thromboplastin time (APTT), LA sensitive APTT and dilute Russell viper venom time (dRVVT) (screening and confirmatory) and ACAs (ELISA). LA was detected in 15 % patients using dRVVT confirmatory test and ACA in 5 %, all controls being negative. Twenty one % patients were detected by LA sensitive APTT (sensitivity 92.9 %, specificity 100 %) and 100 % with dRVVT screening test (sensitivity 98.8 %, specificity 100 %). We recommend that screening for antiphospholipid antibodies must be done in women with spontaneous/recurrent foetal loss even in the absence of other clinical manifestations using a combination of tests.