Size Attenuated Copper Doped Zirconia Nanoparticles Enhances In Vitro Antimicrobial Properties

Biofilm formation hinders the activity of antimicrobial drugs at the site of infections and any agent that can act on both Gram-positive and Gram-negative bacteria by inhibiting the bacterial growth and rupturing the biofilm is needed to manage infection. In the present study, we have synthesized zirconia nanoparticles (ZrO₂ NPs) and copper doped zirconia nanoparticles (Cu-ZrO₂ NPs) and characterized them using dynamic light scattering, X-ray diffractometry, and scanning electron microscopy (SEM). The size of the Cu-ZrO₂ NPs drastically reduced compared to ZrO₂ NPs, and the antimicrobial activity was studied against Gram-positive bacteria (Lactobacillus sp.) and Gram-negative bacteria (Pseudomonas aeruginosa), respectively. The synthesized Cu-ZrO₂ NPs showed superior inhibitory action against Lactobacillus sp. compared to ZrO₂ NPs, due to the negatively charged cell wall of Lactobacillus sp., which could attract readily the positively charged Cu-ZrO₂ NPs, thereby inhibiting its activity. The biocompatibility was tested using XTT assay in FL cells, and the results demonstrated that Cu-ZrO₂ NPs were nontoxic to mammalian cells. Hence, it could be proposed that the synthesized Cu-ZrO₂ NPs possess possible biomedical applications and can be used as antibacterial agents without causing toxicity in mammalian cells.

Impact of diabetes on the severity of COVID-19 infection in pregnant women - A single-center descriptive study

BACKGROUND AND AIMS

Pregnant women have significant morbidity and mortality due to COVID-19 infection. Pregnancy and diabetes are known risk factors for severe COVID 19 infection. Understanding the interactions between COVID-19 and diabetes in pregnancy is crucial in developing appropriate therapeutic approaches. India, like many other countries, has a very high prevalence of diabetes and COVID-19 infected cases. Such studies are minimal worldwide and none from India to the best of our knowledge.

MATERIALS AND METHODS

We did a retrospective cross-sectional study. 856 COVID-19 infected pregnant women were included in the study. We estimated the impact of diabetes on the severity of COVID-19 infected pregnant women and compared the outcomes with the non-diabetic group.

RESULTS

Prevalence of diabetes in pregnancy in the present study was 15.43%(n = 132/856). Prevalence of diabetes in non-severe infection was 14%(n = 115/818), severe infection was 44.73%(n = 17/38), and in maternal deaths was 75% (n = 6/8). The age-adjusted odds ratio for diabetes for severe infection was 4.492 (95% CI = 2.277-8.865, p < 0.001). COVID-19 infected pregnant women with diabetes were at higher risk for Cesarean section (78.3%) and ICU admission for newborns (14.81%) CONCLUSION: Diabetes in pregnant women is strongly associated with the severity of COVID-19 infection. The prevalence of diabetes in pregnancy increases as the severity of COVID-19 infection increases. Diabetes is associated with more adverse outcomes in mothers and newborns. It is necessary to identify pregnant women with diabetes and prioritize them in public health interventions like vaccination.

Prevalence and Risk Factors of Neonatal Covid-19 Infection: A Single-Centre Observational Study

Background

This study is to estimate the prevalence and to determine the risk factors for neonatal Covid-19 infection

Methods

Retrospective analysis of all deliveries in Covid-19-infected mothers in a tertiary care centre in North Kerala from 15 April 2020 to 15 October 2020

Results

Of the 350 Covid-19-positive pregnancies 223 delivered, two were intrauterine foetal demises. In total, 32 out of 221 newborns were Covid-19-positive (14.47%). The risk was more in vaginal delivery group (17.39%) compared to caesarean group (13.16%). The breastfeeding and rooming-in group (18.79%) had more infection than those babies who were not breastfed and separated from mother (1.78%).14 out of 86 (16.28%) babies delivered within 7 days of mothers turning negative became positive compared to 2 out of 23 (8.7%) babies delivered between 7 and 14 days of negative result (Odds ratio of 2.04). None of the babies delivered 14 days after negative result has become positive.

Conclusions

The present study shows that neonatal Covid-19 infection is not rare. The risk is greater in vaginal delivery group and those babies who are breastfed and allowed to stay with mothers. Delaying delivery more than 7 days after mother becoming negative protects the newborn from getting infection

Molecular docking studies of gyrase inhibitors: weighing earlier screening bedrock

For any antimicrobial assay, a standard drug is used to compare the bactericidal efficiency of the bioactive compound under screening. The standard drugs have different targets that may be intracellular or membrane located. The location of the target is believed to be determining the bioactivity of the drug depending on the drug's access to its target. Therefore, different drugs must have a different magnitude in exhibiting the biological effect. However, in most of the published literature about the screening of bioactive compounds on antimicrobial activity, generally, the standard drug is randomly chosen while comparing against the bioactive compound of interest. Further, the antimicrobial activity is inferred by comparing the randomly chosen standard drugs without knowing the physicochemical parameters of the standard drug and the test molecule. It is just like an unfair comparison of the impact of a bullet with the impact of an explosive in a combat scene. Computer-based strategies for structure-based drug discovery presents a valuable alternative to the costly and time-consuming process of random screening. The docking studies provide better insights into the binding mechanism of substrate and inhibitor at the molecular level. The evaluation of such a comparison of bioactive compounds against randomly selected standard drugs through a customized virtual screening pipeline showed 57% false positives, 18% true positive, 17% true negative, 8% false-negative results. This study directs for mandatory cheminformatics-based assessment of the bioactive compounds before choosing the standard drug to compare with.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-020-00064-9.

Postmenopausal hyperandrogenism of ovarian origin: A clinicopathologic study of five cases

In postmenopausal women presenting with virilization and elevated testosterone levels, laparoscopic salpingo-oophorectomy should be considered after exclusion of adrenal causes. A clinicopathological study was conducted among those women who presented with features of hyperandrogenism in our postmenopausal clinic over a period of 2 years. Relevant past medical and surgical histories were elicited. Basic hormonal evaluation and radiological imaging were done. Laparoscopic bilateral salpingo-oophorectomy was done. Six weeks postoperatively, serum testosterone was undetectable with significant clinical improvement. There was no recurrence of symptoms during the follow-up period of 2 years. Treatment of postmenopausal women with hyperandrogenism and virilization with laparoscopic bilateral salpingo-oophorectomy is effective if she has no pronounced ovarian enlargement or adrenal tumor on imaging. An extensive endocrine testing and a detailed search for metastatic disease may be unnecessary.

Position-dependent activity of CELF2 in the regulation of splicing and implications for signal-responsive regulation in T cells

CELF2 is an RNA binding protein that has been implicated in developmental and signal-dependent splicing in the heart, brain and T cells. In the heart, CELF2 expression decreases during development, while in T cells CELF2 expression increases both during development and in response to antigen-induced signaling events. Although hundreds of CELF2-responsive splicing events have been identified in both heart and T cells, the way in which CELF2 functions has not been broadly investigated. Here we use CLIP-Seq to identified physical targets of CELF2 in a cultured human T cell line. By comparing the results with known functional targets of CELF2 splicing regulation from the same cell line we demonstrate a generalizable position-dependence of CELF2 activity that is consistent with previous mechanistic studies of individual CELF2 target genes in heart and brain. Strikingly, this general position-dependence is sufficient to explain the bi-directional activity of CELF2 on 2 T cell targets recently reported. Therefore, we propose that the location of CELF2 binding around an exon is a primary predictor of CELF2 function in a broad range of cellular contexts.

Effect of super dosing of phytase on growth performance, ileal digestibility and bone characteristics in broilers fed corn-soya-based diets

A feeding trial was designed to assess the effect of super dosing of phytase in corn-soya-based diets of broiler chicken. One hundred and sixty-eight day-old broilers were selected and randomly allocated to four dietary treatment groups, with 6 replicates having 7 chicks per treatment group. Two-phased diets were used. The starter and finisher diet was fed from 0 to 3 weeks and 4 to 5 weeks of age respectively. The dietary treatments were consisted of normal phosphorus (NP) group without any phytase enzyme (4.5 g/kg available/non-phytin phosphorus (P) during starter and 4.0 g/kg during finisher phase), three low-phosphorus (LP) groups (3.2 g/kg available/non-phytin P during starter and 2.8 g/kg during finisher phase) supplemented with phytase at 500, 2500, 5000 FTU/kg diet, respectively, to full fill their phosphorus requirements. The results showed that super doses of phytase (at 2500 FTU and 5000 FTU/kg) on low-phosphorus diet improved feed intake, body weight gain, ileal digestibility (serine, aspartic acid, calcium, phosphorus), blood P levels and bone minerals such as calcium (Ca), P, magnesium (Mg) and zinc (Zn) content. It could be concluded that super doses of phytase in low-phosphorus diet were beneficial than the normal standard dose (at 500 FTU/kg) of phytase in diet of broiler chicken.

Alternative splicing networks regulated by signaling in human T cells

The formation and execution of a productive immune response requires the maturation of competent T cells and a robust change in cellular activity upon antigen challenge. Such changes in cellular function depend on regulated alterations to protein expression. Previous research has focused on defining transcriptional changes that regulate protein expression during T-cell maturation and antigen stimulation. Here, we globally analyze another critical process in gene regulation during T-cell stimulation, alternative splicing. Specifically, we use RNA-seq profiling to identify 178 exons in 168 genes that exhibit robust changes in inclusion in response to stimulation of a human T-cell line. Supporting an important role for the global coordination of alternative splicing following T-cell stimulation, these signal-responsive exons are significantly enriched in genes with functional annotations specifically related to immune response. The vast majority of these genes also exhibit differential alternative splicing between naive and activated primary T cells. Comparison of the responsiveness of splicing to various stimuli in the cultured and primary T cells further reveals at least three distinct networks of signal-induced alternative splicing events. Importantly, we find that each regulatory network is specifically associated with distinct sequence features, suggesting that they are controlled by independent regulatory mechanisms. These results thus provide a basis for elucidating mechanisms of signal pathway-specific regulation of alternative splicing during T-cell stimulation.

Dengue reporter virus particles for measuring neutralizing antibodies against each of the four dengue serotypes

The lack of reliable, high-throughput tools for characterizing anti-dengue virus (DENV) antibodies in large numbers of serum samples has been an obstacle in understanding the impact of neutralizing antibodies on disease progression and vaccine efficacy. A reporter system using pseudoinfectious DENV reporter virus particles (RVPs) was previously developed by others to facilitate the genetic manipulation and biological characterization of DENV virions. In the current study, we demonstrate the diagnostic utility of DENV RVPs for measuring neutralizing antibodies in human serum samples against all four DENV serotypes, with attention to the suitability of DENV RVPs for large-scale, long-term studies. DENV RVPs used against human sera yielded serotype-specific responses and reproducible neutralization titers that were in statistical agreement with Plaque Reduction Neutralization Test (PRNT) results. DENV RVPs were also used to measure neutralization titers against the four DENV serotypes in a panel of human sera from a clinical study of dengue patients. The high-throughput capability, stability, rapidity, and reproducibility of assays using DENV RVPs offer advantages for detecting immune responses that can be applied to large-scale clinical studies of DENV infection and vaccination.

DNA binding restricts the intrinsic conformational flexibility of methyl CpG binding protein 2 (MeCP2)

Mass spectrometry-based hydrogen/deuterium exchange (H/DX) has been used to define the polypeptide backbone dynamics of full-length methyl CpG binding protein 2 (MeCP2) when free in solution and when bound to unmethylated and methylated DNA. Essentially the entire MeCP2 polypeptide chain underwent H/DX at rates faster than could be measured (i.e. complete exchange in ≤10 s), with the exception of the methyl DNA binding domain (MBD). Even the H/DX of the MBD was rapid compared with that of a typical globular protein. Thus, there is no single tertiary structure of MeCP2. Rather, the full-length protein rapidly samples many different conformations when free in solution. When MeCP2 binds to unmethylated DNA, H/DX is slowed several orders of magnitude throughout the MBD. Binding of MeCP2 to methylated DNA led to additional minor H/DX protection, and only locally within the N-terminal portion of the MBD. H/DX also was used to examine the structural dynamics of the isolated MBD carrying three frequent mutations associated with Rett syndrome. The effects of the mutations ranged from very little (R106W) to a substantial increase in conformational sampling (F155S). Our H/DX results have yielded fine resolution mapping of the structure of full-length MeCP2 in the absence and presence of DNA, provided a biochemical basis for understanding MeCP2 function in normal cells, and predicted potential approaches for the treatment of a subset of RTT cases caused by point mutations that destabilize the MBD.

Epigenetic centromere specification directs aurora B accumulation but is insufficient to efficiently correct mitotic errors

Aurora B activity is inhibited when centromeric repeat sequences are absent, although kinetochores can still assemble.

The nearly ubiquitous presence of repetitive centromere DNA sequences across eukaryotic species is in paradoxical contrast to their apparent functional dispensability. Centromeric chromatin is spatially delineated into the kinetochore-forming array of centromere protein A (CENP-A)–containing nucleosomes and the inner centromeric heterochromatin that lacks CENP-A but recruits the aurora B kinase that is necessary for correcting erroneous attachments to the mitotic spindle. We found that the self-perpetuating network of CENPs at the foundation of the kinetochore is intact at a human neocentromere lacking repetitive α-satellite DNA. However, aurora B is inappropriately silenced as a consequence of the altered geometry of the neocentromere, thereby compromising the error correction mechanism. This suggests a model wherein the neocentromere represents a primordial inheritance locus that requires subsequent generation of a robust inner centromere compartment to enhance fidelity of chromosome transmission.

Introducing metallocene into a triazole peptide conjugate reduces its off-rate and enhances its affinity and antiviral potency for HIV-1 gp120

In this work, we identified a high affinity and potency metallocene-containing triazole peptide conjugate that suppresses the interactions of HIV-1 envelope gp120 at both its CD4 and co-receptor binding sites. The ferrocene-peptide conjugate, HNG-156, was formed by an on-resin copper-catalysed [2+3] cycloaddition reaction. Surface plasmon resonance interaction analysis revealed that, compared to a previously reported phenyl-containing triazole conjugate HNG-105 (105), peptide 156 had a higher direct binding affinity for several subtypes of HIV-1 gp120 due mainly to the decreased dissociation rate of the conjugate-gp120 complex. The ferrocene triazole conjugate bound to gp120 of both clade A (92UG037-08) and clade B (YU-2 and SF162) virus subtypes with nanomolar KD in direct binding and inhibited the binding of gp120 to soluble CD4 and to antibodies that bind to HIV-1YU-2 gp120 at both the CD4 binding site and CD4-induced binding sites. HNG-156 showed a close-to nanomolar IC50 for inhibiting cell infection by HIV-1BaL whole virus. The dual receptor site antagonist activity and potency of HNG-156 make it a promising viral envelope inhibitor lead for developing anti-HIV-1 treatments.

A recombinant allosteric lectin antagonist of HIV-1 envelope gp120 interactions

The first, critical stage of HIV-1 infection is fusion of viral and host cellular membranes initiated by a viral envelope glycoprotein gp120. We evaluated the potential to form a chimeric protein entry inhibitor that combines the action of two gp120-targeting molecules, an allosteric peptide inhibitor 12p1 and a higher affinity carbohydrate-binding protein cyanovirin (CVN). In initial mixing experiments, we demonstrated that the inhibitors do not interfere with each other and instead show functional synergy in inhibiting viral cell infection. Based on this, we created a chimera, termed L5, with 12p1 fused to the C-terminal domain of CVN through a linker of five penta-peptide repeats. L5 revealed the same broad specificity as CVN for gp120 from a variety of clades and tropisms. By comparison to CVN, the L5 chimera exhibited substantially increased inhibition of gp120 binding to receptor CD4, coreceptor surrogate mAb 17b and gp120 antibody F105. These binding inhibition effects by the chimera reflected both the high affinity of the CVN domain and the allosteric action of the 12p1 domain. The results open up the possibility to form high potency chimeras, as well as noncovalent mixtures, as leads for HIV-1 envelope antagonism that can overcome potency limits and potential virus mutational resistance for either 12p1 or CVN alone.

Broad-spectrum anti-human immunodeficiency virus (HIV) potential of a peptide HIV type 1 entry inhibitor

The AIDS epidemic continues to spread at an alarming rate worldwide, especially in developing countries. One approach to solving this problem is the generation of anti-human immunodeficiency virus (HIV) compounds with inhibition spectra broad enough to include globally prevailing forms of the virus. We have examined the HIV type 1 (HIV-1) envelope specificity of a recently identified entry inhibitor candidate, HNG-105, using surface plasmon resonance spectroscopy and pseudovirus inhibition assays. The combined results suggest that the HNG-105 molecule may be effective across the HIV-1 subtypes, and they highlight its potential as a lead for developing therapeutic and microbicidal agents to help combat the spread of AIDS.

Recombinant-protein production in insect cells utilizing a hollow-fibre bioreactor

Here, we demonstrate for the first time that the hollow-fibre bioreactor is an excellent tool for the production of Drosophila-expressed recombinant proteins. Using the example of the soluble extracellular portion of the human IL-5 (interleukin 5) receptor alpha expression in S2 (Schneider's Drosophila melanogaster cell line 2) cells, we found that it is possible to produce multi-milligram amounts of functional recombinant protein continuously for several months on a laboratory scale with minimal maintenance requirements. The insect cells grow to high density and express concentrated functional recombinant protein in a small volume, simplifying and economizing downstream purification.