Visualizing the invisible: novel approaches to visualizing bacterial proteins and host-pathogen interactions

Host-pathogen interactions play a critical role in infectious diseases, and understanding the underlying mechanisms is vital for developing effective therapeutic strategies. The visualization and characterization of bacterial proteins within host cells is key to unraveling the dynamics of these interactions. Various protein labeling strategies have emerged as powerful tools for studying host-pathogen interactions, enabling the tracking, localization, and functional analysis of bacterial proteins in real-time. However, the labeling and localization of Salmonella secreted type III secretion system (T3SS) effectors in host cells poses technical challenges. Conventional methods disrupt effector stoichiometry and often result in non-specific staining. Bulky fluorescent protein fusions interfere with effector secretion, while other tagging systems such as 4Cys-FLaSH/Split-GFP suffer from low labeling specificity and a poor signal-to-noise ratio. Recent advances in state-of-the-art techniques have augmented the existing toolkit for monitoring the translocation and dynamics of bacterial effectors. This comprehensive review delves into the bacterial protein labeling strategies and their application in imaging host-pathogen interactions. Lastly, we explore the obstacles faced and potential pathways forward in the realm of protein labeling strategies for visualizing interactions between hosts and pathogens.

A review of digital PET-CT technology: Comparing performance parameters in SiPM integrated digital PET-CT systems

OBJECTIVE

The objective of this study was to perform a narrative review of digital Positron emission tomography-computed tomography (PET-CT) scanners, focussing on the current development in the technology of optimized crystal size and design, the time of flight (ToF) resolution, sensitivity, and axial field of view (AFOV).

KEY FINDINGS

It was observed that significant developments were carried out on the optimization of scintillation crystal size which results in the improvement of spatial resolution. such developments include the upgrade in the AFOV after the integration of SiPM technology, which results in dynamic parametric imaging acquisition in PET and sensitivity boost. The improvement in ToF resolution and the better ToF resolution values, which result in a boost in adequate sensitivity and signal-to-noise ratio (SNR). Other upgrades include the use of the smallest crystal size of 2.76 × 2.76 mm, and the use of the lowest ToF resolution of 214 ps. The use of the largest AFOV of 194 cm with the highest observed NEMA sensitivity of 225 cps/kBq for the total body PET-CT system.

CONCLUSION

Digital PET-CT systems offer various advantages such as a reduction in radiation dose from injected radiopharmaceuticals doses and the overall PET acquisition time with an improved diagnostic certainty. This is because of the better performance of the SiPM detector. Digital PET-CT also has added benefits of the dynamic acquisition and Patlak modeling capabilities into routine clinical practice with the advancement in higher AFOV PET systems.

IMPLICATION

This will help the users choose the best system during the evaluation of the PET-CT for purchase in clinical and research applications. This review will further help in teaching the latest technology and developments in PET-CT systems.

IGF-1 stabilizes goat sperm mitochondrial transmembrane potential and reduces dna fragmentation

BACKGROUND

Antioxidant present in sperm cells protects them from oxidative damage. However, sperm are more susceptible to peroxidative damages due to the loss of these enzymes during cryopreservation and their survival and fertility may be compromised. Insulin like growth factor-1 (IGF-1) has an antioxidant effect and could maintain sperm motility.

OBJECTIVE

To improve seminal parameters, mitochondrial membrane potential (MMP), oxidative status and DNA integrity of buck semen after freeze-thawing by fortification of goat semen diluent with various concentrations of IGF-1.

MATERIALS AND METHODS

Fifty ejaculates were collected and were extended with tris- citric acid- fructose diluent with 10% egg yolk and 6% glycerol with sperm concentrations of 1×108 mL-1. Post-cryopreserved sperm were assessed for motility and a range of other functional parameters.

RESULTS

In post-thaw semen sperm motility, live sperm count, acrosome integrity, hypo-osmotic swelling positive spermatozoa, malondialdehyde (MDA), protein carbonyl content (PCC), TUNEL positive sperm differed significantly (P<0.05) with the various concentrations of IGF-1 used. Sperm functional parameters post-thawing were significantly (P<0.05) better in 250 ng/mL IGF-1. IGF-1 protects against lipid peroxidation by lowering MDA and PCC production, thus reducing the harmful effect of reactive oxygen species. The kidding percentage using the artificial insemination technique was significantly higher ( i.e., 40%) in the group supplemented with 250 ng/mL of IGF-1 than in the non-supplemented group (i.e., 30%).

CONCLUSION

IGF-1 may be used to improve post-thaw semen quality and fertility as measured by actual kidding rate. Doi.org/10.54680/fr23610110312.

Technical and clinical assessment of latest technology SiPM integrated digital PETCT scanner

OBJECTIVE

The aim of this study was to conduct a technical and clinical evaluation of a Silicon Photomultiplier (SiPM) integrated digital Positron Emission Tomography - Computed Tomography (PETCT) Scanner using National Electrical Manufacturers Association (NEMA) NU 2- 2018 standards.

METHODS

System sensitivity was measured by using a NEMA sensitivity phantom. Scatter fraction, count-rate performance, accuracy of count loss, and timing resolution were all computed. Clinical images were acquired and image quality was assessed and compared with published studies.

RESULTS

At 1 cm, tangential, radial, and axial spatial resolutions were 3.02 mm, 3.02 mm, and 2.73 mm at full width half maximum (FWHM), respectively. Sensitivity at centre and 10 cm was 10.359 cps/kBq and 9.741 cps/kBq, respectively. The timing resolution was measured at 372 ps.

CONCLUSION

The digital PETCT exhibits a high-spatial resolution and a superior timing resolution, which advances the diagnostic ability to detect small lesions and boosts the diagnostic confidence.

IMPLICATIONS FOR PRACTICE

Increases clinical relevance by improving the ability to detect and differentiate tiny or low-contrast lesions without compromising radiopharmaceutical dose or overall scan time.

The anti-immune dengue subgenomic flaviviral RNA is present in vesicles in mosquito saliva and is associated with increased infectivity

Mosquito transmission of dengue viruses to humans starts with infection of skin resident cells at the biting site. There is great interest in identifying transmission-enhancing factors in mosquito saliva in order to counteract them. Here we report the discovery of high levels of the anti-immune subgenomic flaviviral RNA (sfRNA) in dengue virus 2-infected mosquito saliva. We established that sfRNA is present in saliva using three different methods: northern blot, RT-qPCR and RNA sequencing. We next show that salivary sfRNA is protected in detergent-sensitive compartments, likely extracellular vesicles. In support of this hypothesis, we visualized viral RNAs in vesicles in mosquito saliva and noted a marked enrichment of signal from 3'UTR sequences, which is consistent with the presence of sfRNA. Furthermore, we show that incubation with mosquito saliva containing higher sfRNA levels results in higher virus infectivity in a human hepatoma cell line and human primary dermal fibroblasts. Transfection of 3'UTR RNA prior to DENV2 infection inhibited type I and III interferon induction and signaling, and enhanced viral replication. Therefore, we posit that sfRNA present in salivary extracellular vesicles is delivered to cells at the biting site to inhibit innate immunity and enhance dengue virus transmission.

Super-Resolution Imaging of Bacterial Secreted Proteins Using Genetic Code Expansion

Type three secretion systems (T3SSs) enable gram-negative bacteria to inject a battery of effector proteins directly into the cytosol of eukaryotic host cells. Upon entry, the injected effector proteins cooperatively modulate eukaryotic signaling pathways and reprogram cellular functions, enabling bacterial entry and survival. Monitoring and localizing these secreted effector proteins in the context of infections provides a footprint for defining the dynamic interface of host-pathogen interactions. However, labeling and imaging bacterial proteins in host cells without disrupting their structure/function is technically challenging. Constructing fluorescent fusion proteins does not resolve this problem, because the fusion proteins jam the secretory apparatus and thus are not secreted. To overcome these obstacles, we recently employed a method for site-specific fluorescent labeling of bacterial secreted effectors, as well as other difficult-to-label proteins, using genetic code expansion (GCE). This paper provides a complete step-by-step protocol to label Salmonella secreted effectors using GCE site-specifically, followed by directions for imaging the subcellular localization of secreted proteins in HeLa cells using direct stochastic optical reconstruction microscopy (dSTORM) Recent findings suggest that the incorporation of non-canonical amino acids (ncAAs) via GCE, followed by bio-orthogonal labeling with tetrazine-containing dyes, is a viable technique for selective labeling and visualization of bacterial secreted proteins and subsequent image analysis in the host. The goal of this article is to provide a straightforward and clear protocol that can be employed by investigators interested in conducting super-resolution imaging using GCE to study various biological processes in bacteria and viruses, as well as host-pathogen interactions.

Constraints on Sub-GeV Dark Matter-Electron Scattering from the CDEX-10 Experiment

We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4  kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80  MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90  MeV/c^{2} with heavy mediators and m_{χ} larger than 100  MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.

Exotic Dark Matter Search with the CDEX-10 Experiment at China's Jinping Underground Laboratory

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46}  cm^{2} (90% C.L.) at DM mass of 10  MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14  MeV/c^{2} for the massless dark photon and bound DM final state, respectively.

Genetic and population diversity of Toxocara cati (Schrank, 1788) Brumpt, 1927, on the basis of the internal transcribed spacer (ITS) region

The present investigation was aimed to study the sequence, phylogenetic and haplotype analyses of Toxocara cati based on the ITS region, along with the genetic diversity, demographic history and population-genetic structure. The maximum likelihood tree based on Kimura 2-parameter model was constructed using the complete ITS region of all the nucleotide sequences (n = 57) of Toxocara spp. and other related ascarid worms available in the GenBank™. It placed all the sequences of T. cati into four major clades designated as T. cati genotypes 1-4 (TcG1-G4). A total of 66 signature nucleotides were identified in the ITS region between genotypes. The median-joining haplotype network displayed a total of 24 haplotypes, with China exhibiting the highest number of haplotypes (h = 20) followed by India (h = 4), and Japan and Russia (h = 1). It indicated a clear distinction between all the four genotypes. The pairwise F_ST values between all the genotypes indicated huge genetic differentiation (> 0.25) between different T. cati genotypes. Moreover, the gene flow (Nm) between T. cati genotypes was very low. Results of AMOVA revealed higher genetic variation between genotypes (92.82%) as compared to the variation within genotypes (7.18%). The neutrality indices and mismatch distributions for the G1-G4 genotypes, Indian isolates and the overall dataset of T. cati indicated either a constant population size or a slight population increase. The geographical distribution of all the genotypes of T. cati is also reported. This is the first report of genotyping of T. cati on the basis of the ITS region.

Association between mental health and executive dysfunction and the moderating effect of urban-rural subpopulation in general adolescents from Shangrao, China: a population-based cross-sectional study

OBJECTIVES

To examine the association between mental health and executive dysfunction in general adolescents, and to identify whether home residence and school location would moderate that association.

DESIGN

A population-based cross-sectional study.

SETTING

A subsample of the Shanghai Children's Health, Education, and Lifestyle Evaluation-Adolescents project. 16 sampled schools in Shangrao city located in downstream Yangtze River in southeast China (December 2018).

PARTICIPANTS

1895 adolescents (48.8% male) which were divided into three subpopulations: (A) adolescents who have urban hukou (ie, household registration in China) and attend urban schools (UU, n=292); (B) adolescents who have rural hukou and attend urban schools (RU, n=819) and (C) adolescents who have rural hukou and attend rural schools (RR, n=784).

MEASURES

The Depression Anxiety and Stress Scale-21 was used to assess adolescent mental health symptoms, and the Behaviour Rating Inventory of Executive Function (parent form) was applied to measure adolescent executive dysfunction in nature setting.

RESULTS

Mental health symptoms were common (depression: 25.2%, anxiety: 53.0%, stress: 19.7%) in our sample, and the prevalence rates were lower among UU adolescents than those among the RR and RU, with intersubgroup differences in screen exposure time explaining most of the variance. We found the three types of symptoms were strongly associated with executive dysfunction in general adolescents. We also observed a marginal moderating effect of urban-rural subgroup on the associations: UU adolescents with depression (OR 6.74, 95% CI 3.75 to 12.12) and anxiety (OR 5.56, 95% CI 1.86 to 16.66) had a higher executive dysfunction risk when compared with RR youths with depression (OR 1.93, 95% CI 0.91 to 4.12) and anxiety (OR 1.80, 95% CI 1.39 to 2.33), respectively.

CONCLUSIONS

Rural adolescents experienced more mental health symptoms, whereas urban individuals with mental health problems had a higher executive dysfunction risk.

Prevalence of incidental and total human immunodeficiency virus, hepatitis B and hepatitis C seropositivity among patients posted for cataract surgery at a tertiary care center in India

Purpose:

To study the prevalence of human immunodeficiency virus (HIV), hepatitis B (HBV), and hepatitis C (HCV) viral seropositive among the patients posted for cataract surgery at a tertiary care center in north India.

Methods:

It was a cross-sectional study done for 30 months duration. All the patients posted for cataract surgery underwent comprehensive ophthalmic evaluation followed by routine hematological workup, including viral markers for HIV, Hepatitis B surface antigen (HBsAg), and anti-HCV. Data were analyzed by the Statistical Package for Social Science (SPSS Version 20).

Results:

A total of 7,316 individuals underwent cataract surgery from Jan 2016 to August 2018, 4,073/7,316 (55.7%) were males. The prevalence for HIV was 58/7,316 (0.8%), HBsAg was 151/7,316 (2.1%), and HCV was 11/7,316 (0.1%); 28/58 (48.3%) HIV positives were unaware of their seropositivity till testing, as were 37/151 (24.5%) of HBsAg positives, and 4/11 (36.4%) HCV positives. There was a significant relationship between the mean age in the patients with HIV (P = 0.002) and anti-HCV (P = 0.045). A majority of the seropositive patients were found to be illiterate (45.6%), followed by educated up to high school level (29.1%), and graduate (25.0%).

Conclusion:

Viral seropositivity was significant among the patients posted for cataract surgery. The eye care providers could refer these patients for counseling and further management for the patient’s and their caretaker’s benefit.

Super-resolution imaging of bacterial pathogens and visualization of their secreted effectors

Recent advances in super-resolution imaging techniques, together with new fluorescent probes have enhanced our understanding of bacterial pathogenesis and their interplay within the host. In this review, we provide an overview of what these techniques have taught us about the bacterial lifestyle, the nucleoid organization, its complex protein secretion systems, as well as the secreted virulence factors.

Expression of the developmental important candidate genes in oocytes, embryos, embryonic stem cells, cumulus cells, and fibroblast cells of buffalo (Bubalus bubalis)

The present study was undertaken to study the expression of the developmental important gene transcripts in immature oocytes, mature oocytes, different stages of IVF produced embryos, embryonic stem (ES), cumulus (BCC), fetal fibroblast (BFF), newborn fibroblast (NBF) and adult fibroblast (BAF) cells of buffalo by semi-quantitative RT-PCR. The expression of GLUT1, HSP70.1, POL A Polymerase, GDF9, BMP15, and SURVIVIN transcripts was found in immature oocytes, mature oocytes, 2-cell, 4-cell, 8-16 cell, morula, and the blastocyst. Interestingly, the CX43 expression was found in oocytes, embryos, and other cell types, but it was not detected in the blastocyst. However, the IFNT expression was found in the blastocyst only, but not in other cells. The buffalo ES cells showed the expression of intracellular and cell surface markers (NANOG, OCT4, SOX2, FOXD3, SSEA-3, SSEA-4, TRA-1-60, and TRA-1-81) and alkaline phosphatase activity. Two ES cell lines (S-line and M-line-II) were continued to survive up to 98th passages (~630 days) and 97th passages (~624 days), respectively. It was interesting to note that GLUT1, CX43, HSP70.1, POL A Polymerase, GDF9, BMP15, and SURVIVIN transcripts (except the IFNT) were expressed in buffalo ES, BCC, BFF, NBF and BAF cells. This is the first preliminary report that the buffalo ES, BCC, BFF, NBF, and BAF cells expressed the several developmental important candidate genes. It is concluded that the expression of the major developmental important genes was not only expressed in the oocytes and embryos but also expressed in the ES, BCC, BFF, NBF, and BAF cells of buffalo.

Differential gene expression in liver of colored broiler chicken divergently selected for residual feed intake

Feed constitutes about 60-70% of the total cost of poultry production. So maximizing the feed efficiency will reduce production cost. The rapid growth in the juvenile period is essential to achieve higher body weight. Therefore, identifying the genes and pathways involved in rapid growth at an early age with a lesser requirement of feed is of utmost importance to further economize the broiler production. The efficiency of feed utilization was measured using RFI (residual feed intake). The present study aimed to estimate the RFI (0-5 week) in a population of indigenously developed colored broiler sire line chicken as well as identifying the differentially expressed genes influencing RFI in high and low RFI groups. The liver samples of high and low RFI broiler chicken aged 35 days were used for microarray analysis. A total of 2798 differentially expressed genes (DEGs) were identified, out of which 913 genes were downregulated and 1885 were upregulated. The fold change varied from - 475.17 to 552.94. A subset of genes was confirmed by qRT-PCR, and outcomes were matched well with microarray data. In the functional annotation study of DEGs, the highest significant GO (Gene Ontology) terms in the biological process included protein transport, protein localization, regulation of apoptosis, and mitochondrial transport. Gene network analysis of these DEGs plays an important role to understand the interaction among genes. Study of the important genes which were differentially expressed and the related molecular pathways in this population may hold the potential for future breeding strategies for augmenting feed efficiency.

Genetic code expansion enables visualization of Salmonella type three secretion system components and secreted effectors

Type three secretion systems enable bacterial pathogens to inject effectors into the cytosol of eukaryotic hosts to reprogram cellular functions. It is technically challenging to label effectors and the secretion machinery without disrupting their structure/function. Herein, we present a new approach for labeling and visualization of previously intractable targets. Using genetic code expansion, we site-specifically labeled SsaP, the substrate specificity switch, and SifA, a here-to-fore unlabeled secreted effector. SsaP was secreted at later infection times; SsaP labeling demonstrated the stochasticity of injectisome and effector expression. SifA was labeled after secretion into host cells via fluorescent unnatural amino acids or non-fluorescent labels and a subsequent click reaction. We demonstrate the superiority of imaging after genetic code expansion compared to small molecule tags. It provides an alternative for labeling proteins that do not tolerate N- or C-terminal tags or fluorophores and thus is widely applicable to other secreted effectors and small proteins.

Status of Beta Defensin-1 and its Effect on Post-thaw Semen Fertility Gene Expression in Indian Goat Breed

BACKGROUND

Defensins are antimicrobial peptides and uniformly spans the entire sperm surface and is not exclusive to a specific domain. Goat β-defensin-1 helps in initiation of motility and capacitation of sperm.

OBJECTIVE

To know the status of β-defensin-1 in blood, semen and its effect on post thaw fertility gene expression in Indian goat breeds.

MATERIALS AND METHODS

Semen was extended and divided for estimation of β-defensin-1 and cryopreserved having different concentrations of β-defensin-1.

RESULTS

Bet defensin-1 concentration (pg/mL) in neat semen, sperm pellet and seminal plasma was significantly higher (P< 0.05) in goat breed Barbari followed by Jamunapari and Jakhrana. β-defensing-1 was also high in Jakhrana blood followed by Barbari and Jamunapari. The post thaw motility, live sperm, acrosome intactness and hypo osmotic swelled sperms were significantly higher (P< 0.05) with 10 ng/mL β-defensin in the semen dilutor.

CONCLUSION

Beta defensin (10 ng/mL) in semen dilutor may be used as immuno-modulator to get better post thaw quality suitable for artificial insemination.

Association of TYRP1 with hypoxia and its correlation with patient outcome in uveal melanoma

PURPOSE

Molecular mechanisms of uveal melanoma development in association with high pigmentation are unclear. Tyrosinase Related Protein (TYRP1) is not only one of the important melanogenesis marker that contributes to melanin synthesis, but can also prevents the melanocyte death. The induction of melanogenesis leads to induction of HIF-1α which can affect the behavior of melanoma cells and its surrounding environment. The aim of our study was to determine the expression of TYRP1 and HIF-1α at the protein and RNA level and determine its prognostic significance.

METHODS

In the present study, the expression of TYRP1 and HIF-1α was investigated on 61 formalin-fixed paraffin-embedded choroidal melanoma samples by immunohistochemistry. Fresh 50 samples were validated by real-time PCR. Results were correlated with clinicopathological parameters and Kaplan-Meier was performed to determine the prognostic significance.

RESULTS

High immunoexpression of TYRP1 and HIF-1α was present in 61 and 54% of patients, respectively. Both TYRP1 and HIF-1α correlated well with high pigmentation and BAP1 (BRCA1 Associated Protein-1) loss (p < 0.05) at IHC level as well as transcriptional level. There was reduced metastatic free survival in patients with necrosis and this was statistically significant (p = 0.010).

CONCLUSION

Our findings indicate that TYRP1 can be used as a potential biomarker in the development of targeted therapy in UM. Further studies on melanogenesis markers associated with TYRP1 could provide us a better understanding in this field.

Controlling the aqueous growth of urea crystals with different growth inhibitors: a molecular-scale study

Molecular scale understanding of the mechanism of solution-mediated nucleation and the growth of crystalline materials in the presence of growth inhibitors together with the process parameters continues to attract the interest of the scientific community though much headway has been made in recent years. Growth inhibitors can be added to solution of a crystallizing parent molecule to alter the rate of growth of different crystal faces, size and shape of the crystalline materials. In this work, we investigated the effects of a number of shape-controlling inhibitors, such as acetone, biuret and biurea, on the growth kinetics of the various faces of aqueous-grown urea crystals as a means to predictably control the crystal growth morphology. We combined the adsorption energy landscape of various auxiliaries with the kinetics of the molecular growth processes to develop an analytical model to compute the rate of growth as a function of supersaturation and the additive concentration. The model relates the kinetic and thermodynamic aspects of the adsorption of the solute, solvent and additive to provide a quantitative description of the crystal growth. Ab initio periodic dispersion-corrected density functional theory using the hybrid exchange-correlation functional was employed to determine the interfacial structure of the adsorption of various auxiliaries at crystalline surfaces. The calculated adsorption energies of different auxiliaries were employed to examine the role played by these auxiliaries during the aqueous crystallization of urea crystals containing small amounts of additives. Our results showed that the growth of (110), (111) and (1̄1̄1̄) faces were nearly unaltered by the addition of moderate amounts of acetone as it has lower adsorption energies with the surfaces of these faces. Nevertheless, the presence of acetone in the solution reasonably impeded the growth of the (001) face. The addition of biuret or biurea in the solution led to a higher adsorption energy at (001) and (111) faces. Consequently, the low concentration of these additives severely obstructed the growth of (001) and (111) faces as most of the adsorption sites were occupied by these additives. On the other hand, these additives were weakly adsorbed at the (110) face and, hence, the growth of the (110) face largely remained unaltered. Moreover, unlike biuret, biurea considerably inhibited the growth of the (1̄1̄1̄) face. Our results are in agreement with the experimental and computational results reported in the literature.

Comparative evaluation of DTT treated ABO isoagglutinin titres performed by two methods with solid phase red cell adhesion (SPRCA) titres

BACKGROUND AND AIMS

Measurement of actual concentration of IgG requires methods like treatment of serum with dithiothreitol (DTT). This study was aimed at comparing of DTT treated ABO titres performed by conventional test tube technique (CTT) and column agglutination technique (CAT) with HA/SPRCA.

MATERIALS AND METHODS

This was a prospective, observational study conducted from October 2019 to March 2020. All consecutive A, B and O group donors who gave consent for participation were included. All samples were tested by CTT and CAT before and after DTT treatment (pCTT, pCAT) and with HA/SPRCA.

RESULTS

A total of 300 donors were included; 100 each from A, B and O blood group donors. Group O titres were higher than group A/B titres. Group O titres were highest when performed by pCAT, followed by pCTT and lowest by HA/SPRCA. Group A/B titres were highest when performed by HA/SPRCA, followed by pCAT and pCTT for anti-A and highest when performed by pCAT, followed by HA/SPRCA and lowest by pCTT for anti-B.

CONCLUSION

Results obtained by pCAT were closer to results obtained by pCTT, whereas those obtained by HA/SPRCA were variable. SPRCA offers the advantage of automation, no inter-observer variation and less time consumption because IgM interference is not observed with SPRCA, thus providing an alternative to pCTT. However, these methods cannot be used interchangeably and to discern the most suitable method, a clinical impact of these results needs to be studied.

Effects of treatment with a microRNA mimic or inhibitor on the developmental competence, quality, epigenetic status and gene expression of buffalo (Bubalus bubalis) somatic cell nuclear transfer embryos

Expression levels of 13 microRNAs (miRNAs) were compared between buffalo blastocysts produced by somatic cell nuclear transfer through hand-made cloning and IVF to improve cloning efficiency. Expression of miR-22, miR-145, miR-374a and miR-30c was higher, whereas that of miR-29b, miR-101, miR-302b, miR-34a, miR-21 and miR-25 was lower, in nuclear transferred (NT) than IVF embryos; the expression of miR-200b, miR-26a and miR-128 was similar between the two groups. Based on these, miR-145, which is involved in the regulation of pluripotency, was selected for further investigation of NT embryos. miR-145 expression was lowest at the 2-cell stage, increased through the 4-cell stage and was highest at the 8-cell or morula stage in a pattern that was similar between NT and IVF embryos. miR-145 expression was higher in NT than IVF embryos at all stages examined. Treatment of reconstructed embryos 1h after electrofusion with an inhibitor of miR-145 for 1h decreased the apoptotic index and increased the blastocyst rate, total cell number, ratio of cells in the inner cell mass to trophectoderm, global levels of acetylation of histone 3 at lysine 18 and expression of Krueppel-like factor 4 (KLF4), octamer-binding transcription factor 4 (OCT4) and SRY (sex determining region Y)-box 2 (SOX2) in blastocysts. Treatment with an miR-145 mimic had the opposite effects. In conclusion, treatment of NT embryos with an miR-145 inhibitor improves the developmental competence and quality, and increases histone acetylation and expression of pluripotency-related genes.

Variations in the central corneal thickness during the menstrual cycle in Indian women

Purpose:

To determine the changes in central corneal thickness (CCT) during the menstrual cycle in Indian women.

Methods:

A prospective observational clinical study at a tertiary care center between December 2015 and December 2018. One hundred and twenty sixty women between 18 and 45 years were included. The CCT was measured using an ultrasound pachymeter at three specific timelines of the menstrual cycle: at the beginning (1^st to 3^rd day), during ovulation time (14^th to 16^th day), and at the end of the cycle (28^th to 33^rd day). Phases of the cycle were confirmed by the urine luteinizing hormone level.

Results:

The mean CCT of both eyes was 541.76 ± 4.21 μm, 559.21 ± 4.50 μm, and 544.52 ± 8.06 μm at the beginning, mid, and end of cycle, respectively. The mean CCT of the right eye was 541.68 ± 4.15 μm, 559.08 ± 4.50 μm, and 544.44 ± 8.06 μm and of the left eye was 541.84 ± 4.27 μm, 559.35 ± 4.50 μm, and 544.61 ± 8.06 μm at the beginning, mid, and end of cycle, respectively.

Conclusion:

The CCT value was significantly (P < 0.001) higher during ovulation compared to the beginning and end of the menstrual cycle. Our study recommends adding menstrual history in the workup of women undergoing refractive surgery as physiological variations in the CCT may result in unexpected surgical outcomes.

Effect of Dickkopf-1 and colony stimulating factor-2 on the developmental competence, quality, gene expression and live birth rate of buffalo (Bubalus bubalis) embryos produced by hand-made cloning

A functional canonical WNT signaling pathway exists in preimplantation embryos and inhibits embryonic development. Recent studies suggest that this pathway is over-expressed in nuclear transferred (NT), compared to IVF embryos. The present study investigated the effects of Dickkopf-1 (DKK1), an inhibitor of canonical WNT signaling pathway and colony stimulating factor-2 (CSF2), an embryokine, on the developmental competence, quality, gene expression and live birth rate of NT buffalo embryos produced by Hand-made cloning (HMC). Following supplementation of the in vitro culture medium on day 5 with DKK1 (100 ng/mL), CSF2 (10 ng/mL), DKK1+CSF2 or no supplementation (control), the blastocyst rate was higher (P < 0.05) with DKK1 and DKK1+CSF2 (42.6 ± 1.4% and 46.6 ± 0.9%, respectively) than with CSF2 or controls (40.6 ± 1.3% and 39.0 ± 1.3%, respectively). The apoptotic index of the blastocysts was lower (P < 0.05) for DKK1, CSF2 and DKK1+CSF2 groups (3.44 ± 0.14, 3.39 ± 0.11 and 3.11 ± 0.22, respectively) compared to controls (6.64 ± 0.25), and was similar to that of the IVF blastocysts (3.67 ± 0.18). Although the total cell number was similar for the DKK1, CSF2, DKK1+CSF2 and control groups (200.4 ± 3.05, 196.4 ± 3.73, 204.7 ± 3.71 and 205 ± 4.03, respectively), the inner cell mass:trophectoderm cell number ratio of DKK1, CSF2 and DKK1+CSF2 groups (0.21 ± 0.01, 0.17 ± 0.01 and 0.22 ± 0.02, respectively) was higher (P < 0.05) than controls (0.13 ± 0.01) and was similar to that of IVF blastocysts (0.19 ± 0.01). Treatment with DKK1 or CSF2 or both increased (P < 0.05) the expression level of OCT4, NANOG,SOX2, GATA6, BCL2, PTEN, P53, FGF4, GLUT1 and IFN-τ, and decreased that of C-MYC, CDX2, CASPASE, DNMT3a, TCF7 and LEF1 in blastocysts, compared to controls. Transfer of DKK1-treated embryos to 13 recipients resulted in 4 pregnancies (30.8%; 2 live births, one abortion and one currently at 9 months of pregnancy) whereas, transfer of DKK1+CSF2-treated embryos to 16 recipients, resulted in 4 pregnancies (25.0%), all of which resulted in live births. No pregnancy was obtained after transfer of control and CSF-treated embryos to 12 and 16 recipients, respectively. These results suggest that DKK1 treatment of NT embryos increases the blastocyst, conception and live birth rate, and improves their quality whereas, CSF2 treatment, does not affect the blastocyst, conception and live birth rate despite improvement in embryo quality.

Constitutive expression of c-REL in uveal melanoma patients: correlation with clinicopathological parameters and patient outcome

PURPOSE

Uveal melanoma (UM) is the most common intraocular cancer with a high mortality rate that requires new research in the field of prevention and treatment. c-REL is a member of the nuclear factor κB (NF-κB) transcription factor family and an emerging regulator of tumorigenesis. Therefore, the objective of the study is to evaluate the constitutive expression of c-REL in uveal melanoma patients and its prognostic significance.

METHODS

Detection of c-REL expression was carried out by immunohistochemistry in all 75 patients, and qRT-PCR performed on 58 fresh cases of uveal melanoma along with IL-6 status. Immunoblot was performed to validate immunohistochemistry results. Expression of c-REL protein correlated with clinicopathological parameters and overall survival of patients.

RESULTS

Immunohistochemistry results revealed nuclear expression of the c-REL protein (56%) in our cases. Out of 75 cases, 31 cases showed nuclear expression, and 11 cases had cytoplasmic expression. qRT-PCR showed upregulation of the REL gene in 56.89% cases at the transcriptional level. There was a statistically significant difference in the overall survival of patients with c-REL nuclear immunopositivity (p = 0.0048). On multivariate analysis, scleral invasion and c-REL nuclear expression found to be an independent prognostic factor (p < 0.05) CONCLUSIONS: To the best of our knowledge, this was the first study reporting the expression of the c-REL protein in uveal melanoma. Strong nuclear immunoexpression of c-Rel suggests NFκB pathway activation which might be involved in the progression of the disease. Differential expression of c-REL protein may be used as an attractive target for the development of anticancer strategies.

Lethal Morel-Lavallée lesion: A forensic radiology-pathology correlation

Morel Lavallée lesion or closed degloving injury is normally associated with severe trauma and occurs when the skin and subcutaneous fatty tissue traumatically and abruptly separated from the underlying fascia thus creating a potential space filled with fluid. MVA is the commonest etiology but large or lethal Morel Lavallée is extremely rare. A 35 years old, female pillion rider was involved in a motor vehicle accident and sustained injuries to the left pelvis and thigh. Emergency laparotomy and intra-op abdominal and bilateral lower limb arteriogram revealed no significant finding. Her general condition and vital signs continued to deteriorate despite aggressive resuscitation and eventually died. Post-Mortem Computed Tomography and Post-Mortem Computed Tomography Angiogram was performed and revealed a large cavity in the left thigh suggestive of a lethal Morel Lavallée lesion. Findings were confirmed by conventional autopsy.

Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300  eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0  keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200  eV/c^{2}.

Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6  GeV/c^{2} among WIMP AM measurements to date.

Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35}  cm^{2} for TI analysis at m_{χ}∼50-180  MeV/c^{2}, and 3×10^{-32}∼9×10^{-38}  cm^{2} for AM analysis at m_{χ}∼75  MeV/c^{2}-3.0  GeV/c^{2}.

Successful transplantation of transfected enriched buffalo (Bubalus bubalis) spermatogonial stem cells to homologous recipients

Genetic modification of spermatogonial stem cells (SSCs) is an alternative method to pronuclear microinjection and somatic cell nuclear transfer for transgenesis in large animals. In the present study, we optimized the process of homologous SSC transplantation in the water buffalo (Bubalus bubalis) using transfected enriched SSCs generated by a non-viral transfection approach. Firstly, the SSC enrichment efficiencies of extracellular matrix components viz. collagen, gelatin, and Datura stramonium agglutinin (DSA) lectin were determined either individually or in combination with Percoll density gradient centrifugation. The highest enrichment was achieved after differential plating with DSA lectin followed by Percoll density gradient centrifugation. Nucleofection showed greater transfection efficiency (68.55 ± 4.56%, P < 0.05) for enriched SSCs in comparison to fugene HD (6.7 ± 0.25%) and lipofectamine 3000 (15.57 ± 0.74%). The transfected enriched SSCs were transplanted into buffalo males under the ultrasound guidance and testis was removed by castration after 7-8 weeks of transplantation. Persistence and localization of donor cells within recipient seminiferous tubules was confirmed using fluorescent microscopy. Further confirmation was done by flow cytometric evaluation of GFP expressing cells among those isolated from two-step enzymatic digestion of recipient testicular parenchyma. In conclusion, we demonstrated for the first time, generation of buffalo transfected enriched SSCs and their successful homologous transplantation in buffaloes. This study represents the first step towards genetic modifications in buffaloes using SSC transplantation technique.

Health risks from PAHs and potentially toxic elements in street dust of a coal mining area in India

Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) (Ba, Zn, Pb, Cu, Cr, Ni, As, Co) were determined in the road dusts of a coal mining area (Dhanbad, India) to assess their content and potential human health risks. Dust samples were collected from sign boards of the heavy traffic road connecting Dhanbad and Sindri. The total PAHs (∑PAHs, all values in mg/kg) content in the road dust samples varied from 3.98 to 13.1, with carcinogenic PAHs content of 14.8-34.4% of the ∑PAHs. Phenanthrene (2.72), fluorene (0.715) and pyrene (0.575) are the major PAHs. Principal component analysis revealed that these PAHs are probably originated from pyrogenic (coal combustion and traffic emission) and petrogenic (coal dust, tyre and road particles) sources. Among the PTEs, the mean content was higher for Ba (293 mg/kg) followed by Zn (224), Pb (128), Cu (52.6), Cr (45.2), Ni (22.0), As (17.5) and Co (8.11). The overall pollution load index varied from 0.43 to 1.0. Source analysis showed that PTEs in the road dust of the study site were derived from traffic emission (Zn, Fe, Mn, Co and Pb), coal dust (Cr, As and Ni) and soil (K, Mg, Ba, Sr and Ca). In general, the PTEs are lower, but the PAHs contents were elevated in the road dust samples. Although the exposure risks from PTEs are low, the risk to children (expressed as hazardous quotient) for As and Pb is near to the permissible limit of 1.0. Cancer risk from PAHs for adult (4.8 × 10^-6) and child (5.3 × 10^-6) has exceeded the acceptable limit of 10^-6.

Relationship of foetal number and parity in Barbari goats to plasma profile of caprine pregnancy-associated glycoprotein (caPAG) during gestation and the early postpartum period

This study was conducted to characterise pregnancy-associated glycoprotein (caPAG) in peripheral plasma during gestation and postpartum periods of nulliparous and multiparous does with one or two foetuses using a caPAG specific two-step sandwich ELISA system. Earliest time-points for detection of pregnancy and foetal number with appropriate cut-off values were identified. Plasma samples from 15 pregnant (multiparous: n = 8; nulliparous: n = 7; during pregnancy and postpartum period) and six non-pregnant (during oestrous cycle) goats were collected and analysed. Mean caPAG concentration was greater than the threshold for pregnancy detection (S-N = 0.40) on d22, peaked on d45 and remained unchanged until parturition. From d45 until parturition, caPAG concentration in multiparous does with two foetuses was 1.4 to 1.8 fold greater (P < 0.001) than those with one foetus. For the ELISA, 0.83 (S-N) was the most appropriate cut-off to differentiate does with two from those with a single foetus with an overall sensitivity and accuracy of 88.9% and 84.7%, respectively. Circulating caPAG concentration in multiparous goats was greater (P < 0.05) compared with nulliparous goats during the early pregnancy and postpartum periods. After parturition, caPAG concentrations markedly decreased and were basal within 14 days postpartum. In conclusion, using the caPAG specific ELISA, results indicated there were unique gestational and postpartum profiles for caPAG concentrations that are affected by number of foetuses and parity of the doe. The marked decrease in concentration of caPAG following parturition indicates there would not be compromising of the detection of subsequent pregnancies in goats using this technique.

Comparative analysis of buffalo (Bubalus bubalis) non-transgenic and transgenic embryos containing human insulin gene, produced by SCNT

Somatic cell nuclear transfer (SCNT), using transgenic donor cells, is a highly efficient method for producing transgenic embryos. We compared the developmental competence, quality and gene expression of transgenic embryos produced by Hand-made cloning from buffalo fetal fibroblasts (BFFs) containing human insulin gene, with non-transgenic embryos produced from BFFs (Controls). The expression vector (pAcISUBC), constructed by inserting human insulin gene between DNA fragments containing mammary gland-specific buffalo β-lactoglobulin (buBLG) promoter and terminator buBLG 3'UTR regions into pAcGFP-N1 vector, was used for obtaining the 11 kb insert for transfection of BFFs by nucleofection. Presence of the transgene in embryos was confirmed by examining GFP expression by RT-PCR and immunofluorescence. The blastocyst rate was lower (P < 0.05) for transgenic embryos than for controls (35.7 ± 1.8% vs 48.7 ± 2.4%). The apoptotic index was higher (P < 0.05) for transgenic than for control blastocysts which, in turn, was higher (P < 0.05) than for IVF counterparts (6.9 ± 0.9, 3.8 ± 0.5 and 1.8 ± 0.3, respectively). The total cell number was similar for transgenic and non-transgenic blastocysts (143.2 ± 17.0 and 137.2 ± 7.6, respectively). The expression level of pro-apoptotic genes BAX and BID but not that of CASP3 and CASP9, and cell cycle check point control-related gene P53 was higher (P < 0.05), and that of development- (IGF-1R and G6PD) and pluripotency-related gene NANOG was lower (P < 0.05) in transgenic than in control embryos. The expression level of epigenetic-related genes DNMT1, DNMT3a and HDAC1 and pluripotency-related gene OCT4 was similar in the two groups. The expression level of BAX, BID, CASP9, P53, DNMT1 and DNMT3a was higher (P < 0.05) and that of OCT4, NANOG IGF-1R and G6PD was lower (P < 0.05) in cloned transgenic than in IVF blastocysts whereas, that of CASP3 and HDAC1 was similar between the two groups. In conclusion, these results suggest that transgenic embryos produced by SCNT have lower developmental competence and quality, and altered gene expression compared to non-transgenic embryos.

Single cell, super-resolution imaging reveals an acid pH-dependent conformational switch in SsrB regulates SPI-2

After Salmonella is phagocytosed, it resides in an acidic vacuole. Its cytoplasm acidifies to pH 5.6; acidification activates pathogenicity island 2 (SPI-2). SPI-2 encodes a type three secretion system whose effectors modify the vacuole, driving endosomal tubulation. Using super-resolution imaging in single bacterial cells, we show that low pH induces expression of the SPI-2 SsrA/B signaling system. Single particle tracking, atomic force microscopy, and single molecule unzipping assays identified pH-dependent stimulation of DNA binding by SsrB. A so-called phosphomimetic form (D56E) was unable to bind to DNA in live cells. Acid-dependent DNA binding was not intrinsic to regulators, as PhoP and OmpR binding was not pH-sensitive. The low level of SPI-2 injectisomes observed in single cells is not due to fluctuating SsrB levels. This work highlights the surprising role that acid pH plays in virulence and intracellular lifestyles of Salmonella; modifying acid survival pathways represents a target for inhibiting Salmonella.

Calcium ionophore enhanced developmental competence and apoptotic dynamics of goat parthenogenetic embryos produced in vitro

Parthenogenetically developed embryos are efficient sources of in vitro embryo production, having less ethical issue and being useful for investigating culture conditions/treatments, early developmental, genomic studies, and homonymous source of stem cells. Keeping its advantages in mind, we aimed to study the effects of different activating agents on embryo production and its quality and gene expression. In the present study, 1348 immature oocytes recovered were parthenogenetically developed to embryos. Usable-quality immature oocytes were collected by puncturing the surface follicles and matured in in vitro maturation (IVM) medium for 27 h in a humidified 5% CO₂ incubator at 38.5°C. The matured oocytes were parthenogenetically activated by exposure to 5 μM calcium ionophore for 5 min or 7% ethanol for 7 min sequentially followed by 4 h incubation in 2 mM 6-DMAP and then in vitro cultured (IVC) in RVCL/G-2 medium for 8 days. Matured oocytes were activated by calcium ionophore, the cleavage rate observed was 76.67 ± 3.47%, and further they developed into 4-cell, 8-16-cell, morula, blastocyst, and hatched blastocyst with 85.30 ± 1.57%, 70.60 ± 2.00%, 45.05 ± 2.66%, 22.89 ± 2.40%, and 5.70 ± 1.97%, respectively. Whereas ethanol-activated oocytes showed cleavage rate of 87.60 ± 1.70% and further culture developed into 4-cell, 8-16 cell, morula, blastocyst, and hatched blastocyst with 86.14 ± 1.03%, 71.56 ± 2.21%, 40.90 ± 2.45%, 19.02 ± 1.26%, and 2.22 ± 0.38%, respectively. Blastocyst developed from calcium ionophore-activated oocytes showed significantly (P < 0.05) higher total cell number (282.25 ± 27.02 vs 206.00 ± 40.46) and a lower apoptotic index (2.42 ± 0.46 vs 4.07 ± 1.44) than blastocyst developed from ethanol-activated oocytes. The relative expression of anti-apoptotic genes (BCL2, BCL2A1, MCL) at different stages of embryos produced by either calcium ionophore or ethanol activation was found to be increased in earlier stages and decreased in later stages of embryonic development. Similarly, when these embryos were subjected to pro-apoptotic genes (BAX, BAD, BAK), expression was found to be slightly higher in blastocysts than other stages. This study shows that calcium ionophore-activated blastocysts were developmentally more competent than the ethanol-activated blastocysts.

Critical Incidents in a Multidisciplinary Intensive Care Unit

We aimed to determine the type and frequency of critical incidents in a multidisciplinary intensive care unit, to determine outcomes consequent to these incidents and to devise corrective strategies.

Prospectively collected data on critical incidents during a 33-month period were analysed. In all, 1918 patients were admitted to the unit during the study period. Each incident was analysed in detail. A system-based corrective strategy was sought for and implemented as appropriate.

In these patients, 280 critical incidents were reported during the study period, resulting in 3.4 incidents per 100 patient days. Airway-related incidents were the most frequent (32.8%) followed by line-related (21.8%) and drug-related (15%) incidents. Thirty-two incidents (11.4%) led to adverse outcomes. There were four deaths that occurred as a direct consequence of or contributed to by the incident, all due to airway-related incidents. A major physiological change occurred in 3.6% of incidents, while 6.4% of incidents resulted in a minor physiological change. Critical incidents were common in our multidisciplinary ICU, although adverse outcomes were rare.

Dietary supplementation of vitamin C: an effective measure for protection against UV-B irradiation using fish as a model organism

The development of UV-B protective mechanisms in aquacultural species is essential for the sustainable production of healthy aqua crop. Freshwater carp Catla catla larvae (13.5 ± 1.12 mg) were fed with a diet containing 0.5% vitamin C (D1) and a control diet (D2) for 40 days. Each group was exposed to two doses of UV-B irradiation: 360 (5 min, D1_{5 min} and D2_{5 min}) and 720 mJ cm^-2 (10 min, D1_{10 min} and D2_{10 min}) for 15 days. Significantly (p < 0.05) higher survival and average weight were recorded in D1 compared to D2 exposed to the same dose. Also, significantly (p < 0.001) higher nitric oxide synthase and lower thiobarbituric acid reactive substances and heat shock protein 70 levels were recorded in D1_{5 min} compared to the other groups. A direct relationship was found between the dose of UV-B and DNA fragmentation in muscles. DNA damage indices such as tail DNA, tail extent moment and olive tail moment were significantly (p < 0.01) lower in D1_{5 min}. Thus, supplementation of vitamin C in the diet provides UV-B protection to larvae.

Role of Ser65, His148 and Thr203 in the Organic Solvent-dependent Spectral Shift in Green Fluorescent Protein

The photophysics of green fluorescent protein (GFP) is remarkable because of its exceptional property of excited state proton transfer (ESPT) and the presence of a functional proton wire. Another interesting property of wild-type GFP is that its absorption and fluorescence excitation spectra are sensitive to the presence of polar organic solvents even at very low concentrations. Here, we use a combination of methodologies including site-specific mutagenesis, absorption spectroscopy, steady-state and time-resolved fluorescence measurements and all-atom molecular dynamics simulations in explicit solvent, to uncover the mechanism behind the unique spectral sensitivity of GFP toward organic solvents. Based on the evidences provided herein, we suggest that organic solvent-induced changes in the proton wire prevent ground state movement of a proton through the wire and thus bring about the spectral changes observed. The present study can not only help to understand the mechanism of proton transfer by further dissecting the intricate steps in GFP photophysics but also encourages to develop GFP-based organic solvent biosensors.

Genetic analysis of growth parameters and survival potential of Jamunapari goats in semiarid tropics

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The estimates of heritability for body weight from birth to 12 months age ranged from 0.10 to 0.43.

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The estimates of heritability for average daily gain (ADG) during various growth phase varied from 0.04 to 0.41.

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The heritability estimates of survival potential for post-weaning period to 12 months of age varied from 0.18 to 0.39.

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The genetic trend of body growth traits at 9 months of age and 12 months of age was positive.

Goats are adaptable to varied farming environments and contribute significantly towards sustainable livestock production and food security. Selective breeding of goats for improved performance is an important component of sustainable production. The objectives of the present study were to determine the most appropriate models of analysis for growth traits, to estimate genetic parameters, survival potential of kids from birth to 12 months of age and to estimate genetic trends for growth traits of Jamunapari kids at different ages. Genetic parameter estimates were obtained from 6590 records generated between 1982 and 2012 from 5922 animals with a pedigree covering over 13 generations. The most parsimonious model for early growth traits included permanent environmental effects due to the dam (PE) and litter effects. Similarly, the most appropriate model for early average daily gain (ADG) between birth and 3 or 6 months also included PE and litter effects. The estimates of heritability for survival from birth to 12 months of age ranged from 0.10 to 0.43. The estimates of heritability for ADG varied from 0.04 to 0.41. In general, higher estimates of heritability were observed when a sire model was fitted in the random effect. There was no genetic variation observed for survival between birth and 3 months of age. However, heritability estimates of between 0.18 and 0.39 were observed for survivability during post-weaning period to 12 months of age. The genetic trend at 9 months of age and 12 months of age was 0.144 kg 0.189 kg per year respectively. The genetic trend at all the ages was positive during the study period.

Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg×day Data of the CDEX-10 Experiment

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36}  cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5  GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2  GeV/c^{2}.

Co oxide nanostructures for electrocatalytic water-oxidation: effects of dimensionality and related properties

A facile hydrothermal synthesis route was explored to obtain various nanostructures of Co oxide for applications in electrocatalytic water-splitting. The effect of reaction time and metal precursor ions on the morphology of synthesized nanostructures was studied in detail with the aid of a scanning electron microscope. By systematic optimization of the synthesis parameters, Co oxide nanostructures with single dimensionality were obtained in the form of 0D nanoparticles (NPs), 1D nanowires (NWs), 2D nanosheets (NSs) and 3D nanocrystals (NCs). The effectiveness of the developed nanostructures towards oxygen evolution reaction (OER) was studied and a promising OER activity was recorded for all the samples. Amongst all the developed catalysts, Co(OH)2 NPs showed the lowest overpotential of 339 mV to achieve a current density of 10 mA cm-2, which is even lower than that of noble-metal oxides such as the commercial RuO2 catalyst (370 mV). The specific effect of different parameters such as BET surface area, phase, crystallographic orientation of surface lattice planes, electroactive surface area and surface active species on the OER performance was studied. It was found that the Co3O4 phase is more active for the OER, compared to the Co(OH)2 phase. However, Co(OH)2 NPs showed the best OER performance owing to their higher BET surface area, thereby underlining the significance of the catalyst surface area. The effect of the number of active surface atoms was demonstrated by estimating the electroactive surface area of all Co3O4 nanostructures. It was also shown that the formation of CoO2 species (Co(IV)) on the surface is more beneficial for the OER as compared to the formation of CoOOH species (Co(III)). Finally, the robustness of the developed Co3O4 nanostructures was established by performing a recycling test for the OER (1000 cycles) and the observed change in the catalytic activity was correlated with morphological variation.

The triple-negative (CD34-/HLA-DR-/CD11b-) profile rapidly and specifically identifies an acute promyelocytic leukemia

INTRODUCTION

The genetic testing to confirm or rule out an acute promyelocytic leukemia (APL) typically takes a minimum of 24-72 hours. Flow cytometric immunophenotyping (FCI) on the other hand provides rapid and objective information to differentiate APL from non-APL.

METHODS

FCI features, with single-tube 8-color combination using CD45, CD34, HAL-DR, CD11b, CD13, CD33, and CD117 and CD64, were compared for the 30 consecutive APL and 30 non-APL acute myeloid leukemia (AML) cases which morphologically mimicked an APL. The diagnosis was confirmed by cytogenetic or molecular genetic testing in the form of t (15:17) (q22; q21)/variant translocations or PML-RARA fusion transcript analysis.

RESULTS

The APL cells lacked CD34, HLA-DR, and CD11b in 90%, 90%, and 93.3% cases, respectively. Myeloid antigens such as CD33, CD13, CD117, and CD64 were expressed in 96.7%, 96.7%, 76.7%, and 70% cases, respectively. The dual negative profiles, CD34-/HLA-DR- or HLA-DR-/CD11b-, were noted in 90% and 93.3% cases. The triple-negative (CD34-/HLA-DR-/CD11b-) profile was noted in 90% of the cases. The sensitivity, specificity, and positive predictive value (PPV) of CD34-/HLA-DR- and HLA-DR-/CD11b- profiles for the diagnosis of APL were found to be 90%, 80% & 81.1% and 93.3%, 86.7%& 87.5%, respectively. Combining the above two profiles resulted in a triple-negative profile (CD34-, HLA-DR- and CD11b-), which had a better specificity (93.3%) and positive predictive value (93.1%), with similar sensitivity.

CONCLUSION

FCI is a rapid and reliable modality for the diagnosis of an APL. The triple-negative profile (CD34-/HLA-DR-/CD11b-) rapidly and specifically identifies an APL case.

Effect of T·T Mismatch on DNA Dynamics Probed by Minor Groove Binders: Comparison of Dynamic Stokes Shifts of Hoechst and DAPI

Recognition of DNA base mismatches and their subsequent repair by enzymes is vital for genomic stability. However, it is difficult to comprehend such a process in which enzymes sense and repair different types of mismatches with different ability. It has been suggested that the differential structural changes of mismatched bases act as cues to the repair enzymes, although the effect of such DNA structural changes on surrounding water and ion dynamics is inevitable due to strong electrostatic coupling among them. Thus, collective dynamics of DNA, water, and ions near the mismatch site is believed to be important for mismatch recognition and repair mechanism. Here we show that introduction of a T·T mismatch in the minor groove of DNA induces dispersed (collective) power-law solvation dynamics (of exponent ∼0.24), measured by monitoring the time-resolved fluorescence Stokes shifts (TRFSS) of two popular minor groove binders (Hoechst 33258 and DAPI) over five decades of time from 100 fs to 10 ns. The same ligands however sense different dynamics (power-law of exponent ∼0.15 or power-law multiplied with biexponential relaxation) in the minor groove of normal-DNA. The similar fluorescence anisotropy decays of ligands measured in normal- and T·T-DNA suggest that Stokes shift dynamics and their changes in T·T-DNA purely originate from the solvation process, and not from any internal rotational motion of probe-ligands. The dispersed power-law solvation dynamics seen in T·T-DNA indicate that the ligands do not sense any particular (exponential) relaxation specific to T·T wobbling and/or other conformational changes. This could be the reason why T·T mismatch is recognized by enzymes with lower efficiency compared to purine-pyrimidine and purine-purine mismatches.

Induced pluripotent stem cell: A headway in reprogramming with promising approach in regenerative biology

Since the embryonic stem cells have knocked the doorsteps, they have proved themselves in the field of science, research, and medicines, but the hovered restrictions confine their application in human welfare. Alternate approaches used to reprogram the cells to the pluripotent state were not up to par, but the innovation of induced pluripotent stem cells (iPSCs) paved a new hope for the researchers. Soon after the discovery, iPSCs technology is undergoing renaissance day by day, i.e., from the use of genetic material to recombinant proteins and now only chemicals are employed to convert somatic cells to iPSCs. Thus, this technique is moving straightforward and productive at an astonishing pace. Here, we provide a brief introduction to iPSCs, the mechanism and methods for their generation, their prevailing and prospective applications and the future opportunities that can be expected from them.

Purely Visible-Light-Induced Photochromism in Ag-TiO2 Nanoheterostructures

We report titania nanoheterostructures decorated with silver, exhibiting tuneable photochromic properties for the first time when stimulated only by visible white light (domestic indoor lamp), with no UV wavelengths. Photochromic materials show reversible color changes under light exposure. However, all inorganic photochromic nanoparticles (NPs) require UV light to operate. Conventionally, multicolor photochromism in Ag-TiO₂ films involves a change in color to brownish-gray during UV-light irradiation (i.e., reduction of Ag⁺ to Ag⁰) and a (re)bleaching (i.e., (re)oxidation of Ag⁰ to colorless Ag⁺) upon visible-light exposure. In this work, on the contrary, we demonstrate visible-light-induced photochromism (ranging from yellow to violet) of 1-10 mol % Ag-modified titania NPs using both spectroscopic and colorimetric CIEL*a*b* analyses. This is not a bleaching of the UV-induced color but a change in color itself under exposure to visible light, and it is shown to be a completely different mechanism-driven by the interfacial charge transfer of an electron from the valence band of TiO₂ to that of the Ag_xO clusters that surround the titania-to the usual UV-triggered photochromism reported in titania-based materials. The quantity of Ag or irradiation time dictated the magnitude and degree of tuneability of the color change, from pale yellow to dark blue, with a rapid change visible only after a few seconds, and the intensity and red shift of surface plasmon resonance induced under visible light also increased. This effect was reversible after annealing in the dark at 100 °C/15 min. Photocatalytic activity under visible light was also assessed against the abatement of nitrogen oxide pollutants, for interior use, therefore showing the coexistence of photochromism and photocatalysis-both triggered by the same wavelength-in the same material, making it a multifunctional material. Moreover, we also demonstrate and explain why X-ray photoelectron spectroscopy is an unreliable technique with such materials.

Robotics in hepatobiliary surgery-initial experience, first reported case series from India

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Utility of robotic system for heterogenous mix of hepatobiliary cases.

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Ability of robotic system to perform complex hepatobiliary cases.

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Advantages of minimal access surgery but at a higher cost.

Introduction

Robotic surgical system's ability to perform complex hepatobiliary surgeries is gaining momentum with outcomes similar to open surgery and advantages of minimal access surgery. The authors present their initial experience of a heterogenous spectrum of robotic hepatobiliary cases and the first reported case series from India.

Methods

Retrospective review of hepatobiliary cases done robotically from February 2015 to January 2016 was done.

Results

The series has ten patients; with median age of 45 years (range 15–72). Etiologies were choledochal cyst type IVa, benign lower end common bile duct stricture (biliary reconstruction group); incidental gallbladder carcinoma, hepatocellular carcinoma, recurrent pyogenic cholangitis, polycystic liver disease, hemangioma, liver metastases, hydatid cyst (resection group). Median operative duration was 510 min; one patient needed intra-operative blood transfusion and there were no conversions to open surgery. One patient developed bile leak which was managed by biliary stenting and another thrombotic thrombocytopenic purpura during post-operative period. Median length of hospital stay was 6 days with average cost of robotic surgery being $1700 USD more for major hepatectomy and $900 USD more for biliary reconstruction compared to open procedure.

Conclusion

This initial series adds to existing data on the feasibility of robotic hepatobiliary cases with inherent advantages of minimal invasive surgery, however with limitation of availability and use of devices like cavitron ultrasonic surgical aspirator (CUSA) and higher operative cost.