Biochemical Predictors of Acute Kidney Injury in Critically Ill COVID-19 Patients.

It is estimated that 50% of patients with coronavirus disease 2019 (COVID-19) have varying degrees of renal involvement. In this clinical biomarker development research, we examined in a retrospective study design the temporal changes in biochemical laboratory parameters in relation to the development of acute kidney injury (AKI). In a sample of 399 patients admitted from May 2020 to May 2021 to a tertiary health care intensive care unit (ICU), the incidence of AKI was 27.3%, and the median time to AKI was on 7th day of ICU admission. Most common etiology of AKI was kidney hypoperfusion. Within 72 h of developmental of low blood pressure, 63.76% developed AKI. The likelihood of AKI was higher in those with elevated serum ferritin, aspartate transaminase, and thrombocytopenia (low platelet count). A cutoff value of 750.3 ng/mL [area under the ROC curve (AUC) = 0.777] for serum ferritin, and 40.05 U/L for alanine aminotransferase (AUC = 0.677) 1 day before development of AKI displayed, respectively, a sensitivity of 76.2% and 64.3%, whereas the specificity was 69.5% and 64.1%, respectively, for these two biochemical predictors. A cutoff value of platelets (152.50 × 109/L [AUC = 0.75]) measured 4 days before development of AKI, displayed 83.3% sensitivity and 16.4% specificity. Taken together, our study thoroughly examined the temporal association of various clinical and laboratory parameters with AKI and prediction models were developed as per results of the time series data. These observations in a tertiary health care setting contribute to ongoing efforts for biomarker discovery and development using routine biochemical tests so as to forecast AKI in patients with COVID-19.

Autophagy Underlies the Proteostasis Mechanisms of Artemisinin Resistance in P. falciparum Malaria.

Emerging resistance to artemisinin (ART) has become a challenge for reducing worldwide malaria mortality and morbidity. The C580Y mutation in Plasmodium falciparum Kelch13 has been identified as the major determinant for ART resistance in the background of other mutations, which include the T38I mutation in autophagy-related protein PfATG18. Increased endoplasmic reticulum phosphatidylinositol-3-phosphate (ER-PI3P) vesiculation, unfolded protein response (UPR), and oxidative stress are the proteostasis mechanisms proposed to cause ART resistance. While UPR and PI3P are known to stimulate autophagy in higher organisms to clear misfolded proteins, participation of the parasite autophagy machinery in these mechanisms of ART resistance has not yet been experimentally demonstrated. Our study establishes that ART-induced ER stress leads to increased expression of P. falciparum autophagy proteins through induction of the UPR. Furthermore, the ART-resistant K13C580Y isolate shows higher basal expression levels of autophagy proteins than those of its isogenic counterpart, and this magnifies under starvation conditions. The copresence of PfK13 with PfATG18 and PI3P on parasite hemoglobin-trafficking vesicles demonstrate interactions between the autophagy and hemoglobin endocytosis pathways proposed to be involved in ART resistance. Analysis of PfK13 mutations in 2,517 field isolates, revealing an impressive >85% coassociation between PfK13 C580Y and PfATG18 T38I, together with our experimental studies with an ART-resistant P. falciparum strain establishes that parasite autophagy underpins various mechanisms of ART resistance and is a starting point to further explore this pathway for developing antimalarials. IMPORTANCE There is an urgent need to clearly understand the mechanisms of ART resistance as it is emerging in the Greater Mekong Subregion (GMS) and other parts of the world, such as Africa. Deciphering the mechanisms of the parasite's stress response pathways of ART resistance will provide insights to identify novel drug targets for developing new antimalarial regimens.

Characteristics and outcomes of parturients with COVID-19, admitted to a critical care unit: A single-center retrospective observational study.

Background: Data on outcomes of coronavirus disease 2019 (COVID-19) in pregnancy are scarce, although they represent a unique physiological state affecting both the mother and child. We present collated data from a tertiary care center in North India, encompassing the outcome, clinical characteristics, and management of these patients. Materials and Methods: Parturients ≥ 18 years old, with COVID-19 reverse transcriptase polymerase chain reaction positive for severe acute respiratory syndrome coronavirus 2, requiring intensive care unit (ICU) admission at a tertiary care hospital were included. Data were retrospectively collected from April 2020 to November 2021. Results: In all, 26 parturients were admitted to ICU with COVID-19. Five patients were admitted during the first wave, and all were asymptomatic. Twenty-one patients presented during the second wave (March 2021 onward), among which four were asymptomatic and 17 symptomatic (all with severe pneumonia). Three patients presented in the second trimester, all with critical disease, out of which one did not survive. Two patients had twin gestation, and others were singleton pregnancies. Seven patients (27%) were primigravida, and five patients (19.2%) had more than third pregnancy. Twenty critically ill women (77%) delivered during the hospital stay. Six patients died during the second wave, and four deaths (66.7%) were because of COVID-19 acute respiratory distress syndrome (ARDS). Conclusions: The number of admissions and mortality related to COVID-19 ARDS was higher in the second wave than in the first. We report the safe use of remdesivir and tocilizumab in our patients.

Effect of head-end of bed elevation on respiratory mechanics in mechanically ventilated patients with moderate-to-severe COVID-19 ARDS - A cohort study.

Background: Head-end elevation (HEE) is known to improve oxygenation and respiratory mechanics. In ARDS, poor lung compliance limits positive pressure ventilation causing delivery of inadequate minute ventilation (MVe). We observed that, in moderate-to-severe COVID-19 ARDS, the respiratory system compliance (Crs) reduces upon elevating the head-end of the bed, and vice-versa, which can be utilized to improve ventilation and avoid respiratory acidosis.We hypothesized that increasing the degree of HEE reduces Crs. Methods: We included 20 consecutive mechanically ventilated, moderate-to-severe COVID-19 ARDS patients in this pilot study (CTRI/2021/06/034,182). The Crs, Mve and Rinsp were recorded at 0°, 10°, 20° and 30° HEE. Repeated measures ANOVA was used to determine significant differences in measurements with increasing degrees and repeated measures correlation (rmcorr) for correlation. Results: Repeated measures ANOVA showed a significant difference (p < 0.0001) between values of Crs, MVe and Rinsp. Rmcorr showed a strong negative correlation between increasing degrees and Crs and Mve (r-0.87 [95% CI -0.79 to -0.92, p < 0.0001 and r-0.77 [95% CI -0.64 to -0.85, p < 0.0001]) and a moderate negative correlation for Rinsp (r-0.67; 95% CI -0.79 to -0.50; p < 0.0001). Conclusions: Increasing degree of HEE reduces compliance in moderate-to-severe COVID-19 ARDS. Reducing HEE may optimize ventilation and mitigate ventilator induced lung injury.

Pulmonary Function, Mental and Physical Health in Recovered COVID-19 Patients Requiring Invasive Versus Non-invasive Oxygen Therapy: A Prospective Follow-Up Study Post-ICU Discharge.

Background Survivors of COVID-19 pneumonia may have residual lung injury and poor physical and mental health even after discharge. We hypothesized that COVID-19 severe acute respiratory distress syndrome (ARDS) patients needing mechanical ventilation may be at a greater risk of deterioration in pulmonary function, mental health, and quality of life (QOL). This study analyses the differences in pulmonary function, mental health, and QOL after recovery, in patients having received non-invasive oxygen therapy versus invasive mechanical ventilation during ICU stay. Methods Patients aged >18 years, who had completed 3 months post ICU discharge, with moderate to severe COVID-19 ARDS, were consecutively enrolled from May 1 to July 31, 2021. Patients were allocated into Group A - having required high flow nasal cannula (HFNC)/non-invasive ventilation (NIV) and Group B - having received invasive mechanical ventilation. Pulmonary function tests, 6-minute walk test (6-MWT), and health-related quality of life were compared. Results Of the 145 eligible patients, 31 were lost to follow-up and 21 died. Seventy-four patients were allocated into Groups A (57 patients) and B (17 patients). In Group A, abnormal forced expiratory volume in first second (FEV1), forced vital capacity (FVC), forced expiratory flow in mid-half of FVC (FEF25-75), and peak expiratory flow rate (PEFR) values were obtained in 27 (47.37%), 43 (75.44%), 11 (19.3%), and 25 (43.86%) patients, and in Group B, in 13 (76.47%), 17 (100%), 1 (5.88%), and 8 (47%) patients, respectively. No patient had abnormal FEV1/FVC. All Group B patients had a restrictive pattern in spirometry as compared to 77% in Group A. Group B had a lower arterial partial pressure of oxygen (PaO2) (p=0.0019), % predicted FVC (p<0.0001), % predicted FEV1 (p=0.001), and 6-MWT distance (p<0.001). The physical component score in the short-form survey 12 questionnaire was higher in group A, p<0.001, whereas the mental component score was comparable. Conclusions Patients requiring invasive mechanical ventilation (MV) have a greater risk of impaired pulmonary function and reduced QOL post-ICU discharge. This warrants a greater need for following these patients for better rehabilitation.

Videolaryngoscopic versus direct laryngoscopic paraglossal intubation for cleft lip/palate reconstructive surgeries: A randomised controlled trial.

BACKGROUND AND AIMS: In the cleft lip and palate, the laryngoscope blade often tends to lodge inside midline clefts, causing reduced manoeuvrability and tissue trauma. The paraglossal technique avoids the midline and offers better Cormack Lehane (CL) grades. We aimed to assess the first-pass intubation rate in performing the left paraglossal laryngoscopy with a curved-blade videolaryngoscope (VLS) versus direct laryngoscope (DLS) in children with cleft palate and evaluate the time taken for successful endotracheal intubation (TTI) and Intubation Difficulty Score (IDS) with both devices. METHODS: This randomised controlled trial included 60 patients with cleft palate, between 3 months and 6 years. Patients were randomised into group V (VLS) (n = 30) and group D (DLS) (n = 30). Left paraglossal laryngoscopy was done with VLS or DLS, and the first-pass intubation, TTI, CL grade and IDS were recorded. RESULTS: First-pass intubation (primary outcome) was successful in all cases in group V and in 29 (96%) cases in group D (P = 0.923). Amongst the secondary outcomes, the IDS of the majority in both groups was 1-4 (slight difficulty) (P = 0.98) and the mean TTI In group D was 34.6 s (SD = 19.0) (95% CI: 27.5-41.7) versus 39.8 s (SD = 5.2) (95% CI: 37.8-41.7) in group V (P = 0.151). CONCLUSIONS: There was no significant difference in the use of a VLS over a DLS in performing the left paraglossal laryngoscopy in terms of first-pass intubation rate, CL Grade, IDS and TTI. Further studies with different VLS may be done to improve the ease of this technique.

Structural Analysis of PfSec62-Autophagy Interacting Motifs (AIM) and PfAtg8 Interactions for Its Implications in RecovER-phagy in Plasmodium falciparum.

Autophagy is a degradative pathway associated with many pathological and physiological processes crucial for cell survival. During ER stress, while selective autophagy occurs via ER-phagy, the re-establishment of physiologic ER homeostasis upon resolution of a transient ER stress is mediated by recovER-phagy. Recent studies demonstrated that recovER-phagy is governed via association of Sec62 as an ER-resident autophagy receptor through its autophagy interacting motifs (AIM)/LC3-interacting region (LIR) toAtg8/LC3. Atg8 is an autophagy protein, which is central to autophagosome formation and maturation. Plasmodium falciparum Atg8 (PfAtg8) has both autophagic and non-autophagic functions critical for parasite survival. Since Plasmodium also has Sec62 in the ER membrane and is prone to ER stress due to drastic transformation during their complex intraerythrocytic cycle; hence, we initiated the studies to check whether recovER-phagy occurs in the parasite. To achieve this, a comprehensive study based on the computational approaches was carried out. This study embarks upon identification of AIM sequences in PfSec62 by carrying out peptide-protein docking simulations and comparing the interactions of these AIMs with PfAtg8, based on the molecular dynamic simulations. Detailed analysis is based on electrostatic surface complementarity, peptide-protein interaction strength, mapping of non-covalent bond interactions and rupture force calculated from steered MD simulations. Potential mean forces and unbinding free energies (ΔGdissociation) using Jarzynski's equality were also computed for the AIM/LIR motif complexes with PfAtg8/HsLC3 autophagy proteins to understand their dissociation free energy profiles and thereby their binding affinities and stability of the peptide-protein complexes. Through this study, we predict Sec62 mediated recovER-phagy in Plasmodium falciparum, which might open new avenues to explore novel drug targets for antimalarial drug discovery.

An allosteric inhibitor of Mycobacterium tuberculosis ArgJ: Implications to a novel combinatorial therapy.

The existing treatment regime against tuberculosis is not adequate, and novel therapeutic interventions are required to target Mycobacterium tuberculosis (Mtb) pathogenesis. We report Pranlukast (PRK) as a novel allosteric inhibitor of Mtb's arginine biosynthetic enzyme, Ornithine acetyltransferase (MtArgJ). PRK treatment remarkably abates the survival of free as well as macrophage-internalized Mtb, and shows enhanced efficacy in combination with standard-of-care drugs. Notably, PRK also reduces the 5-lipoxygenase (5-LO) signaling in the infected macrophages, thereby surmounting an enhanced response against intracellular pathogen. Further, treatment with PRK alone or with rifampicin leads to significant decrease in Mtb burden and tubercular granulomas in Mtb-infected mice lungs. Taken together, this study demonstrates a novel allosteric inhibitor of MtArgJ, which acts as a dual-edged sword, by targeting the intracellular bacteria as well as the bacterial pro-survival signaling in the host. PRK is highly effective against in vitro and in vivo survival of Mtb and being an FDA-approved drug, it shows a potential for development of advanced combinatorial therapy against tuberculosis.

CBR antimicrobials inhibit RNA polymerase via at least two bridge-helix cap-mediated effects on nucleotide addition.

RNA polymerase inhibitors like the CBR class that target the enzyme's complex catalytic center are attractive leads for new antimicrobials. Catalysis by RNA polymerase involves multiple rearrangements of bridge helix, trigger loop, and active-center side chains that isomerize the triphosphate of bound NTP and two Mg(2+) ions from a preinsertion state to a reactive configuration. CBR inhibitors target a crevice between the N-terminal portion of the bridge helix and a surrounding cap region within which the bridge helix is thought to rearrange during the nucleotide addition cycle. We report crystal structures of CBR inhibitor/Escherichia coli RNA polymerase complexes as well as biochemical tests that establish two distinct effects of the inhibitors on the RNA polymerase catalytic site. One effect involves inhibition of trigger-loop folding via the F loop in the cap, which affects both nucleotide addition and hydrolysis of 3'-terminal dinucleotides in certain backtracked complexes. The second effect is trigger-loop independent, affects only nucleotide addition and pyrophosphorolysis, and may involve inhibition of bridge-helix movements that facilitate reactive triphosphate alignment.

Leu432Val polymorphism in CYP1B1 as a susceptible factor towards predisposition to primary open-angle glaucoma.

PURPOSE: Defects in cytochrome P450 1B1 (CYP1B1) cause primary congenital glaucoma. However, defects in the gene have also been reported in primary open-angle glaucoma (POAG). Since POAG is primarily a complex disease, we examined the potential of coding single nucleotide polymorphisms (cSNPs) in the gene for association with the disease. METHODS: Five coding SNPs - c.514 C>G (Arg48Gly), c.727 G>T (Ala119Ser), c.1666 C>G (Leu432Val), c.1719 C>T (Asp449Asp), and c.1730 A>G (Asn453Ser) - were genotyped in 264 unrelated POAG patients and 95 controls. In addition, 542 normal individuals selected from various ethnic groups representing the Indian population were also genotyped for these cSNPs. The patterns of linkage disequilibrium between the SNPs and haplotype variations for comparison between POAG patients and controls as well as different ethnic groups of the Indian population were determined using Haploview. Allelic variants of Leu432Val were cloned by site-directed mutagenesis of normal CYP1B1 cDNA, which were used for transfection of retinal pigment epithelium (RPE) cells. The generation of reactive oxygen species (ROS) was quantified by measuring fluorescence emission by degradation of CM-H2DCFDA using a fluoremeter. RESULTS: The c.1666G allele of the Leu432Val in CYP1B1 showed a statistically significant higher representation among POAG patients compared to controls (p=0.0001; Odds ratio=6.027; 95% CI: 3.863-9.401) suggesting it to be a potential risk allele toward disease predisposition. Analysis of genotype frequencies of the polymorphism between the two groups demonstrated GG as a potential risk genotype (p=0.0001; Odds ratio=15.505; 95% CI: 5.529-43.474) for the disease. CYP1B1 Val432 was estimated to generate higher ROS in RPE cells compared to its allelic variant (Leu432; p=0.0245 for 15 min and p=0.0197 for 30 min). Comparison of haplotype diversities revealed CGGTA as the risk haplotype for the disease (p=0.0001, by Fisher's exact test). CONCLUSIONS: We report CYP1B1 c.1666G (Val432) as a susceptible allele for POAG and CGGTA as the risk haplotype for the disease. Higher ROS generation by Val432 in CYP1B1 might lead to apoptotic change that leads to glaucoma. Remarkable variation of the cSNPs observed among ethnic groups of India could provide insight for future epidemiological studies on POAG in these population groups.