Mycorrhization in trees: ecology, physiology, emerging technologies and beyond

Mycorrhization has been an integral part of plants since colonization by the early land plants. Over decades, substantial research has highlighted its potential role in improving nutritional efficiency and growth, development and survival of crop plants. However, the focus of this review is trees. Evidence have been provided to explain ecological and physiological significance of mycorrhization in trees. Advances in recent technologies (e.g., metagenomics, artificial intelligence, machine learning, agricultural drones) may open new windows to apply this knowledge in promoting tree growth in forest ecosystems. Dual mycorrhization relationships in trees and even triple relationships among trees, mycorrhizal fungi and bacteria offer an interesting physiological system to understand how plants interact with other organisms for better survival. Besides, studies indicate additional roles of mycorrhization in learning, memorizing and communication between host trees through a common mycorrhizal network (CMN). Recent observations in trees suggest that mycorrhization may even promote tolerance to multiple abiotic (e.g., drought, salt, heavy metal stress) and biotic (e.g. fungi) stresses. Due to the extent of physiological reliance, local adaptation of trees is heavily impacted by the mycorrhizal community. This knowledge opens the possibility of a non-GMO avenue to promote tree growth and development. Indeed, mycorrhization could impact growth of trees in nurserys and subsequent survival of the inoculated trees in field conditions. Future studies might integrate hyperspectral imaging and drone technologies to identify tree communities that are deficient in nitrogen and spray mycorrhizal spore formulations on them.

Health equity and gendered border blindness: an exploration of healthcare services at the international border in Rajasthan

OBJECTIVES

Citizens' access to health care and the delivery of the healthcare services is significantly affected by the spatiality of the regions and the connectedness of the elements of the healthcare system. This network of healthcare system, region and delivery of services faces myriad challenges in the borderland geography, which is characterised by accentuated military presence, poor physical infrastructure, disinterest of habitation near the border, lack of adequate, necessary and allied services such as schools and industry, social seclusion, migration etc. All these factors amalgamate to create an effect of gender-blind phenomenon as well as border-blind phenomenon. This is particularly acute for women and children.

STUDY DESIGN

A phenomenology research design has been used for the study. It encapsulates qualitative aspects of the views of those who experience marginalisation inclusive of gender-blind experiences. Marginalised women and frontline healthcare workers at the borderland were considered for the inquiry in this study. The study is a composite description of the phenomenon.

METHODS

The border districts of Rajasthan from the Radcliffe line of Rajasthan have been identified for the purpose of the study. Using narrative ethnography along with interviews, an examination was executed from health professionals and marginalised women to comprehend health care access and equity from the service provider's perspective as well as the beneficiary's perspective.

RESULTS

The study provides a range of attributions based on which it could be established that health inequities exist in bordering rural areas.

CONCLUSIONS

The study realises the geopolitical influence of the Radcliffe line, where borderlands are commonly vital to the continuum struggle between the centre and state. Yet, there remains a gap towards implementing various schemes and services due to varied reasons for access from main to far-off border areas, making the situation vulnerable from a resource deficiency point of view. The Health Equity Framework cannot meet Social Determinants of Health in borderland areas of Rajasthan.

CNS Control after First-Line Osimertinib in Patients with Metastatic EGFR-Mutant NSCLC

PURPOSE/OBJECTIVE(S)

Although osimertinib (osi) has excellent intracranial activity in EGFR-mutant metastatic non-small cell lung cancer (NSCLC), there is no consensus regarding whether to continue osi for central nervous system (CNS) control with second-line chemotherapy (chemo) at the time of systemic progression. We aimed to compare CNS outcomes after first-line osi in patients receiving second-line chemo with or without continuation of osi.

MATERIALS/METHODS

We retrospectively reviewed patients with EGFR-mutant NSCLC with brain metastases (BrM) at the time of initiating first-line osi who experienced progression and started second-line chemo. Cumulative incidence of local and distant CNS progression, and extracranial (EC) progression was calculated from time of second-line chemo initiation with death as a competing risk. Overall survival (OS) was analyzed using Kaplan-Meier.

RESULTS

We included 52 patients with a median follow up of 9.6 months (range 0.4-36.4). Median OS and CNS progression-free survival (PFS) from the time of starting second-line chemo was 12.5 months (95% CI 8.1-16.9), and 5.3 months (95% CI 3.35-7.26), respectively. The 1-year cumulative incidence of local, distant CNS progression, any CNS progression, and EC progression was 14.4% (95% CI 4.5-24.2), 42.8% (95% CI 22.8-56.8), 42.8% (95% CI 22.8-56.8) and 66.8% (95% CI 53.5-80.2), respectively. After progression on first-line osi, 25 (48.1%) and 27 patients (51.9%) continued and discontinued osi, respectively. Patients who continued osi had significantly higher BrM burden than those who did not, with 17 (68%), 3 (12%), and 5 (20%) versus 26 (96%), 0, and 1 (3.7%) patient having <10 or >11 parenchymal brain lesions, or leptomeningeal disease (LMD) at the time of second line therapy, respectively (p<0.01). In those who continued osi vs those who did not, median OS (10.8 vs 12.5 months; p = 0.37), median intracranial PFS (5.3 vs 4.8 months; p = 0.99), 1-year cumulative incidence of local (8.4% versus 20 % p = 0.26), and 1-year distant CNS progression (24.8% vs 60%; p = 0.08) was not significantly different. CNS complications such as symptomatic, hospitalizations, and steroid initiation for CNS disease, and progression of LMD were not significantly different between the two groups. Eventually, 10 patients underwent salvage RT post first-line osi and median time to salvage RT was 7.8 months (range 2-9.4). Of patients who underwent salvage RT, 2 patients (20%) had continued osi with second-line chemo. Twelve patients (44.4%) who did not continue osi eventually re-started osi for progressive disease.

CONCLUSION

Patients who continued osi had significantly higher BrM tumor burden. Despite these patients being at higher risk for CNS progression, time to CNS progression and incidence of CNS complications were not significantly different in the two cohorts. Patients who discontinued osi were more likely to undergo salvage RT. Continuation of osi may allow patients to defer salvage RT.

Operationalising targeted next-generation sequencing for routine diagnosis of drug-resistant TB

BACKGROUND

Phenotypic drug susceptibility testing (pDST) for Mycobacterium tuberculosis can take up to 8 weeks, while conventional molecular tests identify a limited set of resistance mutations. Targeted next-generation sequencing (tNGS) offers rapid results for predicting comprehensive drug resistance, and this study sought to explore its operational feasibility within a public health laboratory in Mumbai, India.

METHODS

Pulmonary samples from consenting patients testing Xpert MTB-positive were tested for drug resistance by conventional methods and using tNGS. Laboratory operational and logistical implementation experiences from study team members are shared below.

RESULTS

Of the total number of patients tested, 70% (113/161) had no history of previous TB or treatment; however, 88.2% (n = 142) had rifampicin-resistant/multidrug-resistant TB (RR/MDR-TB). There was a high concordance between resistance predictions of tNGS and pDST for most drugs, with tNGS more accurately identifying resistance overall. tNGS was integrated and adapted into the laboratory workflow; however, batching samples caused significantly longer result turnaround time, fastest at 24 days. Manual DNA extraction caused inefficiencies; thus protocol optimisations were performed. Technical expertise was required for analysis of uncharacterised mutations and interpretation of report templates. tNGS cost per sample was US$230, while for pDST this was US$119.

CONCLUSIONS

Implementation of tNGS is feasible in reference laboratories. It can rapidly identify drug resistance and should be considered as a potential alternative to pDST.

Clinical utility of target-based next-generation sequencing for drug-resistant TB

BACKGROUND: In high TB burden countries, access to drug susceptibility testing is a major bottleneck. Targeted next-generation sequencing (tNGS) is a promising technology for rapid resistance detection. This study assessed the role of tNGS for the diagnosis of drug-resistant TB (DR-TB).METHODS: A total of 161 samples from bacteriologically confirmed TB cases were subjected to tNGS using the Deeplex^® Myc-TB kit and sequenced using the MiSeq platform. These samples were also processed for conventional phenotypic DST (pDST) using 13 drugs on Mycobacteria Growth Indicator Tube and line-probe assays (MTBDRplus and MTBDRsl).RESULTS: There were 146 DR-TB and 15 drug-susceptible TB (DS-TB) samples. About 70% of patients with DR-TB had no previous TB treatment history. Overall, 88.2% had rifampicin-resistant/multidrug-resistant TB (RR/MDR-TB), 58.5% pre-extensively drug-resistant TB (pre-XDR-TB) and 9.2% had XDR-TB as defined by the WHO (2020). Around 8% (n = 13) of samples were non-culturable; however, identified 8 were resistant to first and second-line drugs using tNGS. Resistance frequency was similar across methods, with discordance in drugs less reliable using pDST or with limited mutational representation within databases. Sensitivities were aligned with literature reports for most drugs. We observed 10% heteroresistance, while 75% of strains were of Lineages 2 and 3.CONCLUSIONS: Programme data supported tNGS in the diagnosis of DR-TB for early treatment using individualised regimens.

Kidney Organoids Generated Using an Allelic Series of NPHS2 Point Variants Reveal Distinct Intracellular Podocin Mistrafficking

BACKGROUND

NPHS2 variants are the most common cause of steroid-resistant nephrotic syndrome in children >1 month old. Missense NPHS2 variants were reported to cause mistrafficking of the encoded protein, PODOCIN, but this conclusion was on the basis of overexpression in some nonpodocyte cell lines.

METHODS

We generated a series of human induced pluripotent stem cell (iPSC) lines bearing pathogenic missense variants of NPHS2 , encoding the protein changes p.G92C, p.P118L, p.R138Q, p.R168H, and p.R291W, and control lines. iPSC lines were also generated from a patient with steroid-resistant nephrotic syndrome (p.R168H homozygote) and a healthy heterozygous parent. All lines were differentiated into kidney organoids. Immunofluorescence assessed PODOCIN expression and subcellular localization. Podocytes were transcriptionally profiled and PODOCIN-NEPHRIN interaction interrogated.

RESULTS

All variant lines revealed reduced levels of PODOCIN protein in the absence of reduced transcription. Although wild-type PODOCIN localized to the membrane, distinct variant proteins displayed unique patterns of subcellular protein trafficking, some unreported. P118L and R138Q were preferentially retained in the endoplasmic reticulum (ER); R168H and R291W accumulated in the Golgi. Podocyte profiling demonstrated minimal disease-associated transcriptional change. All variants displayed podocyte-specific apoptosis, which was not linked to ER stress. NEPHRIN-PODOCIN colocalization elucidated the variant-specific effect on NEPHRIN association and hence NEPHRIN trafficking.

CONCLUSIONS

Specific variants of endogenous NPHS2 result in distinct subcellular PODOCIN localization within organoid podocytes. Understanding the effect of each variant on protein levels and localization and the effect on NEPHRIN provides additional insight into the pathobiology of NPHS2 variants.

PODCAST

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2023_01_05_JASN2022060707.mp3.

Ethnic heterogeneity in body composition patterning and CVD risk factors: a multi-ethnic study of Asian Indian Tribes

BACKGROUND

Indian subcontinent exhibits considerable degree of ethnic heterogeneity in cardiovascular disease (CVD) risks. Given the importance of ethnicity, the present multi-ethnic study was conducted to find out the differences in body composition patterning and its influence on CVD risk variables.

OBJECTIVE

Owing to considerable ethnic heterogeneity among Asian Indians the study was performed to determine the association of variability between body composition and CVD risk factors at the micro-level among different tribes by sex, province, and generation.

METHODS

Nine tribes from three different states (provinces) were considered. Anthropometric measurements, body composition, adiposity, blood pressure, and fasting blood glucose was measured using standard technique. Body composition was measured using BIA method by means of body fat monitor. Mean differences of the body composition measures were analysed by ANOVA. Stepwise multiple regressions were done with CVD risk variables as dependent and body composition profiles as independent variables to find out the significant predictors. Those were then loaded for principal component factor analyses (PCFA).

RESULTS

Tribal subjects of both sexes and from both younger and older generations in Gujarat had significantly higher percentage body fat, subcutaneous fat-whole body, and subcutaneous fat-trunk as compared to tribal subjects of Odisha, and West Bengal, as well as significantly lower skeletal mass-whole body and skeletal mass-trunk. PCFA showed two components: (i) percentage body fat with muscle mass; and (ii) visceral fat with resting metabolism. These two components cumulatively explained 80-90% of the total variance associated with CVD risk variables, across the nine tribes.

CONCLUSION

Tribal subjects of Gujarat had higher CVD risks with significantly higher fat mass and lower muscle mass followed by the tribal subjects of Odisha, and West Bengal respectively. The younger generation are equally at risk as their older counterparts. The CVD risks are developing at a much faster rate resulting in a serious public health threat, even in traditional societies. Body composition measures could be considered as a better non-invasive technique for early intervention and proper risk management among the Asian Indians in general and tribal populations in particular.

UK multi-centre retrospective study of the learning curve and relative performance of the rhythmia high density mapping system for atrial ablation

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): University Hospital Southampton

Background

Rhythmia HDx® is a novel ultra-high density electroanatomical mapping system using an innovative 64 electrode basket catheter. A learning curve is a recognised phenomenon for any new technology and was examined in this study.

Purpose

Comparison of performance, long-term success, and complications using Rhythmia for atrial ablation in the UK.

Methods

Retrospective data collection from three centres across the UK from the introduction of Rhythmia. Patients were matched with controls who had undergone ablation using the well-established Carto3 mapping system. Assessed were: fluoroscopy, radiofrequency ablation and procedure times; acute and long term success, and complications.

Results

253 study patients with 253 controls were included. Significant correlations existed between procedural efficiency metrics and centre experience for de novo atrial fibrillation (AF) ablation (procedure time, Spearman’s ρ = -0.624; ablation time, ρ = -0.795), and de novo atrial flutter (AFlut) ablation (ablation time, ρ = -0.566; fluoroscopy time, ρ = -0.520). No such correlations existed for redo AF, redo AFlut, de novo atrial tachycardia (AT), or redo AT cases. For de novo AF and AFlut, procedural efficiency metrics were significantly improved after 10 procedures in each centre, (procedure time [AF only, p = 0.001], ablation time [AF, p &lt; 0.0005; AFlut p &lt; 0.0005] and fluoroscopy time [AFlut only, p = 0.0022]), and became comparable to controls (Figures 1 and 2). Acute success and long-term success did not see significant improvement with experience but were comparable to the control group. There was no relationship between experience and complications, which were comparable to Carto3 (3.6% in both groups).

Conclusion

A short learning curve exists with the use of Rhythmia HDx for standardised procedures (de novo AF / AFlut). Procedural performance improves and becomes comparable to Carto3 following 10 cases at each centre. Clinical outcomes at 6 and 12 months, and complications are not affected by this learning curve and remain comparable with controls.

Eruptive keratoacanthomas associated with dupilumab therapy

We would like to present the case of eruptive keratoacanthomas associated with dupilumab therapy, which occurred in an 85-year-old woman receiving biologic therapy for the treatment of atopic dermatitis. With the increasing prevalence of Dupilumab usage, this is an important potential complication of which clinicians should be aware.

Irreversibility Analysis of 3D Magnetohydrodynamic Casson Nanofluid Flow Past Through Two Bi-Directional Stretching Surfaces with Nonlinear Radiation

Application of the nanoparticles with different non-Newtonian base fluid has huge application in the industries where the heat generation or energy transform takes place and many such applications are designing the advanced energy system at high temperature, aerodynamics, energy extraction etc. In the present study, we have analyzed irreversibility for a 3-dimensional MHD, incompressible, electrically conducting Casson nanofluid flow through the two horizontal stretching surfaces. To make it more practical and broad, the flow field has been incorporated with porosity, suction/injection, non-linear radiation with fall velocity with convective heating conditions at the boundaries and entropy generation which is an important physical phenomenon in thermodynamics. Influence of imperative parameters of the flow field and physical parameters have discussed with the entropy generation. In a limiting case, a comparison made. It is observed that the suction phenomena boost up the local Nusselt and Sherwood number at the surface while restricted the skin friction. The non-Newtonian rheology (as Casson number) restricted the skin friction and the same phenomena observed for the local heat and mass transfer. The entropy boosts up with the enhancement of the magnetic parameter, temperature ratio and Brinkman number. Further nanoparticle concentration improve the thermal conductivity leads an improvement in the efficiency of the heat transfer takes place. With the augment in thermal radiation, magnetic parameter and Brinkman number, the entropy generation of the systems gets accelerated.