Investigation of NH3 as a selective thyroid hormone receptor modulator in larval zebrafish (Danio rerio)

Thyroid hormones (THs) are essential for normal vertebrate development and diverse environmental chemicals are hypothesized to cause developmental toxicity by disrupting TH-mediated signaling. The larval zebrafish (Danio rerio) is an emerging in vivo model of developmental TH disruption; however, the effects of TR antagonism have not yet been studied in zebrafish. NH3, generally considered a potent and specific thyroid hormone receptor (TR) antagonist, has been used in rodents and Xenopus laevis to characterize phenotypes of TR antagonism. The objective of this study is to determine the effects of NH3 on endpoints previously determined to be TH-sensitive in larval zebrafish, specifically teratology and mortality, photomotor behavior, and mRNA expression of TH signaling genes. Zebrafish embryos were exposed to NH3 via static waterborne exposure at concentrations ranging from 0.001 to 10 μM beginning at 6 h post-fertilization (hpf) through 5 days post fertilization (dpf). Significant mortality and teratogenesis was observed at 3, 4, and 5 dpf in zebrafish exposed to NH3 at 10 μM. At concentrations that did not cause significant mortality, NH3 did not exert a consistent antagonistic effect on photomotor behavior assays or mRNA expression when administered alone or in the presence of exogenous T4. Rather, depending on the NH3 concentration and larval age NH3 decreased or increased swimming triggered by transition from light to dark. Similarly, inconsistent antagonistic and agonistic effects on mRNA expression of TH signaling genes were noted following treatment with NH3 alone. NH3 did inhibit T4 (30 nM)-induced gene expression; however, this was only consistently observed at a concentration of NH3 (10 μM) that also caused significant mortality. Collectively, these results suggest that NH3 does not act solely as a TR antagonist in larval zebrafish, but instead exhibits complex modulatory effects on TR activity. These data support the hypothesis that NH3 is a selective thyroid hormone receptor modulator. Further studies of NH3 interactions with the zebrafish thyroid hormone receptor are required to characterize the activity of NH3 in target tissues of the larval zebrafish at the molecular level, highlighting the importance of characterizing NH3 effects in specific models of TH-disruption to better interpret its actions in mechanistic screens of environmental chemicals for TH action.

Kv1.3 modulates neuroinflammation and neurodegeneration in Parkinson's disease

Characterization of the key cellular targets contributing to sustained microglial activation in neurodegenerative diseases, including Parkinson's disease (PD), and optimal modulation of these targets can provide potential treatments to halt disease progression. Here, we demonstrated that microglial Kv1.3, a voltage-gated potassium channel, was transcriptionally upregulated in response to aggregated α-synuclein (αSynAgg) stimulation in primary microglial cultures and animal models of PD, as well as in postmortem human PD brains. Patch-clamp electrophysiological studies confirmed that the observed Kv1.3 upregulation translated to increased Kv1.3 channel activity. The kinase Fyn, a risk factor for PD, modulated transcriptional upregulation and posttranslational modification of microglial Kv1.3. Multiple state-of-the-art analyses, including Duolink proximity ligation assay imaging, revealed that Fyn directly bound to Kv1.3 and posttranslationally modified its channel activity. Furthermore, we demonstrated the functional relevance of Kv1.3 in augmenting the neuroinflammatory response by using Kv1.3-KO primary microglia and the Kv1.3-specific small-molecule inhibitor PAP-1, thus highlighting the importance of Kv1.3 in neuroinflammation. Administration of PAP-1 significantly inhibited neurodegeneration and neuroinflammation in multiple animal models of PD. Collectively, our results imply that Fyn-dependent regulation of Kv1.3 channels plays an obligatory role in accentuating the neuroinflammatory response in PD and identify Kv1.3 as a potential therapeutic target for PD.

A facile, sensitive and rapid sensing platform based on CoZnO for detection of fipronil; an environmental toxin

A sensitive detection of extremely toxic phenylpyrazole insecticide, 'Fipronil' is presented. Currently, the advancement of approaches for the detection of insecticides at low concentrations with less time is important for environmental safety assurance. Considering this fact, an effort has been made to develop an electrospun CoZnO nanofiber (NF) based label-free electrochemical system for the detection of fipronil. The CoZnO NF were characterized using different techniques including field emission scanning electron microscopy (FE-SEM), Energy Dispersive X-Ray Analysis (EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Raman Spectroscopy. Based on the experimental results, the proposed platform displayed a linear response for fipronil in the attogram/mL range despite the multiple interfering agents. The sensitivity of the device was found to be 3.99 Kῼ (g/ml)^-1 cm^-2. Limit of detection (LOD) and limit of quantification (LOQ) were calculated and found to be 112 ag mL^-1 and 340 ag mL^-1 respectively. Further, this proposed sensor will be implemented in the fields for the rapid and proficient detection of the real samples.

New capsaicin analogs as molecular rulers to define the permissive conformation of the mouse TRPV1 ligand-binding pocket

The capsaicin receptor TRPV1 is an outstanding representative of ligand-gated ion channels in ligand selectivity and sensitivity. However, molecular interactions that stabilize the ligand-binding pocket in its permissive conformation, and how many permissive conformations the ligand-binding pocket may adopt, remain unclear. To answer these questions, we designed a pair of novel capsaicin analogs to increase or decrease the ligand size by about 1.5 Å without altering ligand chemistry. Together with capsaicin, these ligands form a set of molecular rulers for investigating ligand-induced conformational changes. Computational modeling and functional tests revealed that structurally these ligands alternate between drastically different binding poses but stabilize the ligand-binding pocket in nearly identical permissive conformations; functionally, they all yielded a stable open state despite varying potencies. Our study suggests the existence of an optimal ligand-binding pocket conformation for capsaicin-mediated TRPV1 activation gating, and reveals multiple ligand-channel interactions that stabilize this permissive conformation.

A coded aperture microscope for X-ray fluorescence full-field imaging

The design and construction of an instrument for full-field imaging of the X-ray fluorescence emitted by a fully illuminated sample are presented. The aim is to produce an X-ray microscope with a few micrometers spatial resolution, which does not need to scan the sample. Since the fluorescence from a spatially inhomogeneous sample may contain many fluorescence lines, the optic which will provide the magnification of the emissions must be achromatic, i.e. its optical properties must be energy-independent. The only optics which fulfill this requirement in the X-ray regime are mirrors and pinholes. The throughput of a simple pinhole is very low, so the concept of coded apertures is an attractive extension which improves the throughput by having many pinholes, and retains the achromatic property. Modified uniformly redundant arrays (MURAs) with 10 µm openings and 50% open area have been fabricated using gold in a lithographic technique, fabricated on a 1 µm-thick silicon nitride membrane. The gold is 25 µm thick, offering good contrast up to 20 keV. The silicon nitride is transparent down into the soft X-ray region. MURAs with various orders, from 19 up to 73, as well as their respective negative (a mask where open and closed positions are inversed compared with the original mask), have been made. Having both signs of mask will reduce near-field artifacts and make it possible to correct for any lack of contrast.

Questionnaire based counselling: A tool to identify stress precipitating factors and thereby upgrading the performance of a new medical Entrant in department of anatomy

Background and Aims:

Vast first MBBS course has been posing great problems for a fresh entrant in medical college. A student is merely 18-19 years when he gains entry to a medical college in India. Multiple problems pile up for him at the very onset of his academic year in Department of Anatomy. The present study aimed to identify various stress factors and further assess the effect of counselling/mentorship programme on solving such issues.

Materials and Methods:

A pre-validated, predesigned questionnaire was administered to hundred first year medical students. They were individually counselled with various faculty persons. Based on the questionnaire given, the results were analysed.

Results:

45% of the students were sure that their language problem was solved after the session. 48% students accepted that they did have some adjustment problems, which were solved then. 30% expressed that some of their personal problems were also solved. 54% were now able to manage their time judiciously. 64% opined that counselling helped to plan their studies well. 52% students admitted that counselling improved their performance in theory. 46% expressed that counselling also helped to improve their performance in practicals. 65% told us that their skills both in theory and practical had improved after the session. 39% consented that counselling relieved them of anxiety. 67% recognised that their knowledge in the subject of anatomy had increased. 75% were of the view that similar sessions should be conducted more frequently. 40% preferred to express their views in their regional language. 85% students advised us to carry forward these sessions to the next batches.

Conclusion:

Our study highlights the need for counselling to solve multifaceted adjustment problems.

Swimming statistics of cargo-loaded single bacteria

Burgeoning interest in the area of bacteria-powered micro robotic systems prompted us to study the dynamics of cargo transport by single bacteria. In this paper, we have studied the swimming behaviour of oil-droplets attached as cargo to the cell bodies of single bacteria. The oil-droplet loaded bacteria exhibit super-diffusive motion which is characterised by a high degree of directional persistence. Interestingly, bacteria could navigate with cargo size as large as 8 μm resulting in an increased rotational drag of more than 2 orders when compared to the free bacteria. The directional change of cargo loaded bacterial trajectories seems to be enhanced by steric hindrance from other oil-droplets present in the environment.

Assessment of newly introduced foundation course for medical undergraduates: students' vs faculty's perspective

Background and Objectives:

In compliance with MCI's recommendation, a month-long Foundation Course was conducted in our institution in Aug’19. The present study was conducted to seek the opinion of the students and faculty regarding relevance of the topics included in the course to enable revisions to be made in designing the course for the subsequent sessions, to make it more effective and student-oriented.

Methods:

A questionnaire-based cross-sectional study was conducted to seek the opinion of 100 students who underwent the Foundation Course and 35 faculty members who were involved in teaching the topics allotted.

Results:

Positive feedback was recorded from63% of the students and 69% of the faculty regarding the overall experience of the course. Among the different modules, Skills module was voted as relevant by majority (73%) of students, whereas a module on Enhancement of Language and Computer Skills was found relevant to the course by a mere 52% students. In contrast, module on Sports and Extracurricular activities was adjudged as most relevant while as module on Enhancement of Language and Computer Skills got the least positive feedback (81.43% vs. 60.36%, respectively) from the faculty.

Interpretation and Conclusions:

Foundation Course recommended by MCI for MBBS students at the entry level is a welcome step. This can further be made more beneficial by making necessary modifications in the planning of the course in light of suggestions received from the participants.

Detection of recent infection of Japanese encephalitis virus in swine population using IgM ELISA: A suitable sentinel to predict infection in humans

Japanese encephalitis (JE) is a mosquito-borne flaviviral zoonotic disease and is one of the major causes of encephalitis in children. Swine, being an amplifier host of Japanese encephalitis virus (JEV), play an important role in its epidemiology. Therefore, early detection of either JEV or antibodies against JEV in swine is a feasible alternative for initiating necessary measures to prevent the spread of infection to humans. Since IgM antibodies appear early in swine sera, recombinant NS1 protein based indirect IgM ELISA was developed in the present study with the objective to know the recent infection of swine population with JEV. The relative diagnostic sensitivity and specificity of the developed ELISA was 95.34% and 98.6%, respectively. The developed ELISA was found to have excellent reproducibility on inter-laboratory and inter-institutional validation studies. A total of 3,027 field swine sera samples were screened using the developed ELISA and 488 samples were found positive for IgM against JEV with an overall sero-positivity of 16.12% in swine population of India. The highest sero-positivity was observed in swine population of Eastern zone of India which coincided with the maximum number of human JE cases reported from this zone during the same period. Further, antibody kinetics study revealed that the IgM antibodies against NS1 protein of JEV started appearing in swine sera at day 5 and disappeared completely by day 40. The IgG antibodies started appearing at day 7, and remained for more than 365 days indicating the suitability of IgM ELISA to know the recent infection of JEV. The developed IgM ELISA can be readily incorporated into surveillance programs for detection of JEV activity in swine population so that outbreaks in humans can be prevented by taking suitable preventive measures.

Promoting Antenatal Care: Identifying Policy Levers in Indian Context

Background

The growing body of literature associates Antenatal Care (ANC) with early detection and prevention of maternal complications which in turn reduce the likelihood of maternal and infant death. Studies report that only about 40% of pregnant women in developing countries have attended four ANC visits. This situation mandates identifying policy levers for promoting ANC visits.

Methods

The study uses data from the Demographic and Health Survey (DHS) India (2015-16). We analyze a sample of about 100,000 women in the age group of 15-49 years who gave birth in three years preceding the survey. Using the theory of health seeking behaviour we propose a conceptual model to understand the a) Predisposing factors; b) Enabling factors and c) Need factors affecting the ANC visits in Indian context.

Results

17 % women in our sample never went for ANC. 46 % women in our sample went for at least four ANC visits. SEM analysis suggests that our structural model fits well with the sample data (RMSEA: 0.05; TFI: 0.93; SRMR: 0.038). Higher age, lower parity, higher awareness and higher levels of education significantly predisposes women to go for ANC visits. The significant (95% CI) enablers include higher socio-economic status, meeting with Community Health Worker (CHW) and enrolment in government sponsored nutrition support program. While health system barriers and personal barriers act as disablers. Bad obstetric history and health issues during pregnancy are significant need factors. Our analysis suggests that meeting CHWs increases ANC visits by 1.8 units and enrolment in nutrition support programme increases ANC visits by 1.4 units.

Conclusions

CHW and nutrition support programme are significant policy levers to promote ANC care and reduce maternal and child morbidity and mortality. Antenatal care services must be included under universal health coverage domain to reduce financial barriers for women of low socio-economic strata

Key messages

Involvement of Community Health workers in the promotion of maternal and child health care is a cost-effective strategy. Nutrition support programmes through Anganwadi centres help advance maternal and child health care by promoting ANC care.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Expression of MTNR1A, steroid (ERα, ERβ, and PR) receptor gene transcripts, and the concentration of melatonin and steroid hormones in the ovarian follicles of buffalo

High ambient temperature exhibits a retrograde effect on buffalo reproduction because of heat stress. Moreover, melatonin is known to regulate reproductive changes in seasonally reproductive animals by binding to high affinity, G protein-coupled receptors. The MTNR1A gene is a prime receptor, mediating the effect of melatonin at the neuroendocrine level to control seasonal reproduction. In sheep, the role of melatonin is well known; however, studies have not been conducted in buffalo to determine its effect during favorable and unfavorable breeding seasons. Therefore, the present study aimed to (1) determine the expression of MTNR1A, ERα, ERβ, and PR gene transcripts in the ovarian follicles of buffalo during the summer and winter seasons and (2) analyze melatonin, 17β-estradiol, and progesterone concentrations in the follicular fluid of buffalo during both seasons. Murrah buffalo ovaries were collected during both the summer (May-June) and winter (December-January) seasons. All visible ovarian follicles were allocated into one of three groups: (1) small (8-9.9 mm); (2) medium (10-11.9 mm); and (3) large (12-14 mm). Follicular fluid was aspirated from each group of follicles for hormone analyses. The granulosa cells were processed for RNA extraction. Furthermore, they were subjected to real-time quantitative PCR to analyze the expression (relative quantification) of MTNR1A, ERα, ERβ, and PR in each follicular group. The expression of MTNR1A gene transcript decreased with the increasing size of the follicle and intrafollicular melatonin concentration. Expression of ERα and PR remained unaffected by the season and was similar (P > 0.05) in all groups. Expression of ERβ was higher (P < 0.05) in summer than winter; nevertheless, small-sized follicles from the summer exhibited higher (P < 0.05) expressions than medium- and large-sized follicles. The overall intrafollicular melatonin concentration was positively correlated (P < 0.05) with 17β-estradiol and progesterone concentrations. In conclusion, the decreased expression of MTNR1A and increased concentration of intrafollicular melatonin with the increasing size of the follicle indicates a probable role in folliculogenesis and ovulation in buffalo.

BiOCl/WS2 hybrid nanosheet (2D/2D) heterojunctions for visible-light-driven photocatalytic degradation of organic/inorganic water pollutants

This report presents the superior visible-light-driven photocatalytic response of novel 2D/2D BiOCl/WS₂ (BW _X ) hybrid nanosheet heterojunctions prepared by a simple solution based sonochemical technique. These BW _X hybrid nanosheets are composed of 2D transition metal dichalcogenide material WS₂ and BiOCl nanosheets. The comparative study of photocatalytic activity of BiOCl and BiOCl/WS₂ hybrid nanosheets is carried out via photodegradation of Malachite Green (MG) and photoreduction of heavy metal ion Cr(vi) under visible light irradiation. The quantum efficiency of the samples is estimated in terms of the incident photon to electron conversion efficiency (IPCE) measurements. Nearly 98.4% of the MG degradation was achieved over BiOCl/WS₂ (2%) photocatalyst in 45 min of irradiation. BiOCl/WS₂ (2%) hybrid nanosheet catalyst showed the highest external quantum efficiency (EQE) in both the UV and visible regimes. This accomplishment demonstrated the promise of commercial application of the 2D/2D BiOCl/WS₂ (2%) hybrid nanosheet photocatalyst.

Scrub typhus in patients with acute febrile illness: a 5-year study from India

BACKGROUND

Scrub typhus was once thought to be a disease of rural origin and was confined to specific pockets in South Asia. Early diagnosis and treatment is extremely important as it is associated with high mortality if left untreated.

AIM

To delineate the clinical and molecular epidemiology of scrub typhus in patients presenting with acute febrile illness from various parts of India.

METHODS

During the study period of 5 years (October 2013 to October 2018), a total of 1742 patients with acute febrile illness <15 days were enrolled after taking informed consent. Patients were diagnosed using IgM Enzyme-linked immunosorbent assay (ELISA) based on the pre-determined region specific cut offs. Patients with positive IgM ELISA were also subjected to IgM Immunofluorescence assay and nested polymerase chain reaction (PCR) assay. The demographic and relevant clinical details of the patients were documented and analyzed.

RESULTS

A total of 210 (12.1%) patients were diagnosed with scrub typhus. Of these, nested PCR was positive in only 85 patients. Sequencing and phylogenetic analysis showed that the predominant circulating genotypes were Gilliam and Karp. On multivariate analysis, acute respiratory distress syndrome, myocarditis, encephalitis/encephalopathy, jaundice and splenomegaly were significantly more common in those patients who were diagnosed with scrub typhus. A total of 14 patients diagnosed with scrub typhus succumbed to the illness.

CONCLUSION

Patients with fever, headache, pulmonary manifestations, CNS manifestations, myocarditis, transaminitis or thrombocytopenia presenting in the monsoon and post-monsoon season should be evaluated for scrub typhus irrespective of the geographical location in India.