Publications by authors named "Amrita Samanta"

Article Synopsis
  • Computational tools are increasingly used to identify biological targets of natural products with anticancer effects, particularly the natural product piperlongumine (PL), which interacts with the hTRPV2 channel.
  • Cryo-electron microscopy revealed how PL binds to an allosteric pocket of the rat TRPV2 channel, showcasing a novel anticancer mechanism against glioblastoma (GBM), where the hTRPV2 channel is overexpressed.
  • Research demonstrated that downregulating hTRPV2 decreases sensitivity to PL, and treating GBM in mouse models with PL formulated in a scaffold significantly reduced tumor growth and improved survival, suggesting a new approach for cancer treatment.
View Article and Find Full Text PDF

Transient receptor potential vanilloid 2 (TRPV2) plays a critical role in neuronal development, cardiac function, immunity, and cancer. Cannabidiol (CBD), the non-psychotropic therapeutically active ingredient of , is an activator of TRPV2 and also modulates other transient receptor potential (TRP) channels. Here, we determined structures of the full-length rat TRPV2 channel in apo and CBD-bound states in nanodiscs by cryo-electron microscopy.

View Article and Find Full Text PDF

Objective: To determine whether vaginal application of 40 mg isosorbide-5-mononitrate (ISMN) has a comparable cervical ripening efficacy to and lesser side effects than 400 µg misoprostol in women scheduled for the first trimester induced abortion using a manual vacuum aspirator (MVA).

Methods: We conducted a prospective randomized open-label study in 70 women at 6-12 weeks of pregnancy at the R G Kar Medical College and Hospital, Kolkata, India, over a period of two years from 2015 to 2017. Forty milligrams of ISMN and 400 µg misoprostol were vaginally applied for cervical priming.

View Article and Find Full Text PDF

Cryo electron microscopy (cryo-EM) is a powerful technique that can be used to elucidate the structural architecture of a protein molecule in a physiologically relevant environment. In this method, purified protein is frozen in its aqueous buffer in a thin layer of vitreous ice in which the biological macromolecules are embedded in various orientations. Images of this frozen sample are collected with an electron microscope, and the data is processed using different software algorithms resulting in high-resolution structures of the protein.

View Article and Find Full Text PDF
Article Synopsis
  • TRPV5 is a calcium channel that plays a key role in calcium reabsorption, and this study explores how two natural modulators, PI(4,5)P and calmodulin (CaM), interact with it.
  • The research utilized cryo-electron microscopy to visualize the structure of TRPV5 when bound to PI(4,5)P and CaM, revealing how PI(4,5)P opens the channel and CaM inhibits it.
  • Understanding these interactions enhances our knowledge of TRPV5's modulation, which could be beneficial for future drug development.
View Article and Find Full Text PDF

Pain, though serving the beneficial function of provoking a response to dangerous situations, is an unpleasant sensory and emotional experience. Transient receptor potential ankyrin 1 (TRPA1) is a member of the transient receptor potential (TRP) cation channel family and is localized in "nociceptors," where it plays a key role in the transduction of chemical, inflammatory, and neuropathic pain. TRPA1 is a Ca-permeable, nonselective cation channel that is activated by a large variety of structurally unrelated electrophilic and nonelectrophilic chemical compounds.

View Article and Find Full Text PDF

Transient Receptor Potential (TRP) channels are evolutionarily conserved integral membrane proteins. The mammalian TRP superfamily of ion channels consists of 28 cation permeable channels that are grouped into six subfamilies based on sequence homology (Fig. 6.

View Article and Find Full Text PDF

Serotonin receptors (5-HTR) directly regulate gut movement, and drugs that inhibit 5-HTR function are used to control emetic reflexes associated with gastrointestinal pathologies and cancer therapies. The 5-HTR function involves a finely tuned orchestration of three domain movements that include the ligand-binding domain, the pore domain, and the intracellular domain. Here, we present the structure from the full-length 5-HTR channel in the apo-state determined by single-particle cryo-electron microscopy at a nominal resolution of 4.

View Article and Find Full Text PDF
Article Synopsis
  • The TRPV5 channel is a key player in calcium absorption in the kidney, found mainly in tubular epithelial cells.
  • Recent cryo-EM studies reveal its structure in complex with the inhibitor econazole, showing the inhibitor binds in a hydrophobic pocket similar to other TRP channels.
  • This structure indicates that econazole locks TRPV5 in a closed state, preventing calcium flow, and offers insights into how small molecules can inhibit TRPV channels.
View Article and Find Full Text PDF

Transient receptor potential (TRP) proteins form a superfamily Ca(2+)-permeable cation channels regulated by a range of chemical and physical stimuli. Structural analysis of a 'minimal' TRP vanilloid subtype 1 (TRPV1) elucidated a mechanism of channel activation by agonists through changes in its outer pore region. Though homologous to TRPV1, other TRPV channels (TRPV2-6) are insensitive to TRPV1 activators including heat and vanilloids.

View Article and Find Full Text PDF

Background: Annual mass drug administration (MDA) with diethyl carbamazine (DEC) and Albendazole is the most cost-effective strategy to control lymphatic filariasis (LF).

Materials And Methods: The aim of the present study was to assess the coverage and the compliance of MDA, to elicit factors that influenced compliance, to document side-effects reported and to assess the awareness of the community regarding the disease and MDA program in Bankura district, West Bengal after 2012 round of MDA. Multistage cluster sampling method was adopted.

View Article and Find Full Text PDF

Objectives: To assess the knowledge of interns on standard precautions and post-exposure prophylaxis for HIV, and identify the gap between knowledge and practice relating to standard precautions, as well as determining the perceived barriers against adherence to standard precautions.

Methods: The study was conducted on 130 interns of 2010-11 batch from a government-run medical college in Kolkata, India. All participants completed a self-administered questionnaire with items relating to basic components of standard precautions and post-exposure prophylaxis for HIV.

View Article and Find Full Text PDF

Background & Objectives: Prevention of parent-to-child transmission (PPTCT) services are an integral part of National AIDS Control Programme and their critical appraisal is necessary for improving quality care. The present study was conducted to evaluate the performance of PPTCT services in West Bengal during April, 2008 - March 2009 and April 2009 - March 2010 and identify gaps in service delivery for making suitable recommendations.

Methods: Data were collected from the Computerized Management Information System and validated by cross-checking records at each district.

View Article and Find Full Text PDF

A cross-sectional study was conducted among 199 (104 urban, 95 rural) male students of classes VIII and IX, of two schools, in urban and rural areas of West Bengal to compare the prevalence of protective factors, mental health issues, and violence among the urban and rural adolescents using a self-administered questionnaire. Higher proportion of urban students than rural (67.3% vs.

View Article and Find Full Text PDF

Globally, alcohol-abuse is a major cause of mortality and morbidity. Consumption of alcohol has increased in India in the recent decades. It is imperative to know the patterns of alcohol consumption among different types of consumers to launch a well-planned nationwide programme for the prevention and control of this devastating social pathology.

View Article and Find Full Text PDF

A community-based, descriptive, cross-sectional study was conducted in Purushottampur village of the Singur block, Hooghly, using a pre-tested, semi-structured questionnaire, to find out the prevalence of RTI / STI symptomatics among the general population aged 15 to 49 years, and to assess their profiles and health-seeking behaviors. Prevalence of (Reproductive tract infection) RTI / STI (Sexually transmitted infections) symptoms in the last 12 months was found to be 13.9 and 13.

View Article and Find Full Text PDF