Ambulatory blood pressure monitoring in pheochromocytoma - paraganglioma: A single center experience

CONTEXT/AIMS

Pheochromocytoma and paraganglioma (PPGL) are rare tumors, and data on ambulatory blood pressure monitoring (ABPM) in these patients and the effect of blocking on ABPM parameters is limited. We aimed to describe ABPM parameters in a cohort of PPGL at our center in western India.

METHODS

Retrospective study of patients with PPGL whose ABPM data was available. Demographic details, secretory status, and ABPM data were retrieved. Coefficient of variability (CV) was calculated as standard deviation/mean in percentage.

RESULTS

In the 39 included patients, mean age at presentation was 39.3 ± 14.2 yr; 20 (51.3%) were males, 25 (64.1%) hypertensive, and mean tumor diameter was 5.3 cm. In 18 patients whose baseline ABPM was done without medications, those with nocturnal blood pressure dipping (6/18, 33%) had higher serum metanephrines (median 313.2 vs. 34.7 pg/ml, P = 0.028). Despite normal office blood pressure (BP), 8.9% of systolic BP readings were >140 mmHg, and 1.2% were >160 mmHg. Among 29 patients with both pre and post-block ABPM, mean BP (systolic 121.6 vs. 132.5 mmHg, P = 0.014; diastolic 68.9 vs. 76.4 mmHg, P = 0.005) and percentage of BP readings above 140 mmHg (median 9.4% vs. 24.4%, P = 0.016) were significantly lowered after the preoperative blockade in hypertensive ( n = 19) patients, whereas CV was similar. The post-blockade ABPM characteristics were similar in patients blocked with amlodipine or prazosin.

CONCLUSION

ABPM provides additional information about BP characteristics in PPGL. The preoperative blocking decreases the magnitude of BP excursions but does not affect BP variability.

Significant enhancement in the cold emission characteristics of chemically synthesized super-hydrophobic zinc oxide rods by nickel doping

The current article presents a huge enhancement in the field emission characteristics of zinc oxide (ZnO) micro/nanorods by nickel doping. The synthesis of pure and nickel-doped zinc oxide (ZnO) micro/nanorods was done by a simple low-temperature chemical method. Both the as-prepared pure and doped samples were analyzed by X-ray diffraction and electron microscopy to confirm the proper phase formation and the developed microstructure. UV-vis transmittance spectra helped in determining the band gap of the samples. Fourier-Transform Infrared Spectroscopy (FTIR) spectra showed the different bonds present in the sample, whereas X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of nickel in the doped sample. Photoluminescence (PL) spectra showed that after doping, the band-to-band transition was affected, whereas defect-induced transition had increased significantly. After the nickel doping, contact angle measurement revealed a significant decrease in the sample's surface energy, leading to a remarkably high water contact angle (within the superhydrophobic region). Simulation through ANSYS suggested that the doped sample has the potential to function as an efficient cold emitter, which was also verified experimentally. The cold emission characteristics of the doped sample showed a significant improvement, with the turn-on field (corresponding to J = 1 μA cm-2) reduced from 5.34 to 2.84 V μm-1. The enhancement factor for the doped sample reached 3426, approximately 1.5 times higher compared to pure ZnO. Efforts have been made to explain the results, given the favorable band bending as well as the increased number of effective emission sites.

Controlled E. coli Aggregation Mediated by DNA and XNA Hybridization

Chemical cell surface modification is a fast-growing field of research, due to its enormous potential in tissue engineering, cell-based immunotherapy, and regenerative medicine. However, engineering of bacterial tissues by chemical cell surface modification has been vastly underexplored and the identification of suitable molecular handles is in dire need. We present here, an orthogonal nucleic acid-protein conjugation strategy to promote artificial bacterial aggregation. This system gathers the high selectivity and stability of linkage to a protein Tag expressed at the cell surface and the modularity and reversibility of aggregation due to oligonucleotide hybridization. For the first time, XNA (xeno nucleic acids in the form of 1,5-anhydrohexitol nucleic acids) were immobilized via covalent, SNAP-tag-mediated interactions on cell surfaces to induce bacterial aggregation.

Projected mid-century rainfall erosivity under climate change over the southeastern United States

Recent observations and climate change projections indicate that changes in rainfall energy, intensity, duration, and frequency, which determine the erosive power of rainfall, will amplify erosion rates around the world. However, the magnitude and scope of these future changes in erosive power of rainfall remain largely unknown, particularly at finer-resolutions and local scales. Due to a lack of available projected future sub-hourly climate data, previous studies relied on aggregates (hourly, daily) rainfall data. The erosivity for the southeastern United States in this study was calculated using the RUSLE2 erosivity calculation method without data limitation and a recently published 15-min precipitation dataset. This precipitation data was derived from five NA-CORDEX climate models' precipitation products under the Representative Concentration Pathway (RCP) 8.5 scenario. In this dataset, hourly climate projections of precipitation were bias-corrected and temporally downscaled to 15-min resolution for 187 locations with collocated 15-min precipitation observations. Precipitation, erosivity (R-factor), and erosivity density (ED) estimations were provided for historical (1970-1999) and future (2030-2059) time periods. Ensemble results for projected values (as compared to historical values) showed increase in precipitation, erosivity, and erosivity density by 14 %, 47 %, and 29 %, respectively. The future ensemble model showed an average annual R-factor of 11,237±1299 MJ mm ha^-1h^-1yr^-1. These findings suggest that changes in rainfall intensity, rather than precipitation amount, may be driving the change in erosivity. However, the bias correction and downscaling limitations inherent in the original precipitation dataset and this study's analyses obscured this particular result. In general, coastal and mountainous regions are expected to experience the greatest absolute increase in erosivity, while other inland areas are expected to experience the greatest relative change. This study offers a novel examination of projected future precipitation characteristics in terms of erosivity and potential future erosion.

Temporal disaggregation of hourly precipitation under changing climate over the Southeast United States

Climate change impacts on precipitation characteristics will alter the hydrologic characteristics, such as peak flows, time to peak, and erosion potential of watersheds. However, many of the currently available climate change datasets are provided at temporal and spatial resolutions that are inadequate to quantify projected changes in hydrologic characteristics of a watershed. Therefore, it is critical to temporally disaggregate coarse-resolution precipitation data to finer resolutions for studies sensitive to precipitation characteristics. In this study, we generated novel 15-minute precipitation datasets from hourly precipitation datasets obtained from five NA-CORDEX downscaled climate models under RCP 8.5 scenario for the historical (1970–1999) and projected (2030–2059) years over the Southeast United States using a modified version of the stochastic method. The results showed conservation of mass of the precipitation inputs. Furthermore, the probability of zero precipitation, variance of precipitation, and maximum precipitation in the disaggregated data matched well with the observed precipitation characteristics. The generated 15-minute precipitation data can be used in all scientific studies that require precipitation data at that resolution.

Measurement(s)	Precipitation
Technology Type(s)	weather station, stochastic
Sample Characteristic - Environment	Climate system
Sample Characteristic - Location	Southeast United States

Improved forest dynamics leads to better hydrological predictions in watershed modeling

This study explored how the characterization of forest processes in hydrologic models affects watershed hydrological responses. To that end, we applied the widely used Soil and Water Assessment Tool (SWAT) model to two forested watersheds in the southeastern United States. Although forests can cover a large portion of watersheds, tree attributes such as leaf area index (LAI), biomass accumulation, and processes such as evapotranspiration (ET) are rarely calibrated in hydrological modeling studies. The advent of freely and readily available remote-sensing data, combined with field observations from forestry studies and published literature, allowed us to develop an improved forest parameterization for SWAT. We tested our proposed parameterization at the watershed scale in Florida and Georgia and compared simulated LAI, biomass, and ET with the default model settings. Our results showed major improvements in predicted monthly LAI and ET based on MODIS reference data (NSE > 0.6). Simulated forest biomass also showed better agreement with the USDA forest biomass gridded data. Through a series of modeling experiments, we isolated the benefits of LAI, biomass, and ET in predicting streamflow and baseflow at the watershed level. The combined benefits of improved LAI, biomass, and ET predictions yielded the most optimal model configuration where terrestrial and in-stream processes were simulated reasonably well. We performed automated model calibration using two calibration strategies. In the first calibration scheme (M₀), SWAT was calibrated for daily streamflow without adjusting LAI, biomass, and ET. In the second calibration scheme (M_LAI+BM+ET), previously calibrated parameters constraining LAI, biomass, and ET were incorporated into the model and daily streamflow was recalibrated. The M_LAI+BM+ET model showed superior performance and reduced uncertainties in predicting daily streamflow, with NSE values ranging from 0.52 to 0.8. Our findings highlight the importance of accurately representing forest dynamics in hydrological models.

Improving the representation of forests in hydrological models

Forests play a critical role in the hydrologic cycle, impacting the surface and groundwater dynamics of watersheds through transpiration, interception, shading, and modification of the atmospheric boundary layer. It is therefore critical that forest dynamics are adequately represented in watershed models, such as the widely applied Soil and Water Assessment Tool (SWAT). SWAT's default parameterization generally produces unrealistic forest growth predictions, which we address here through an improved representation of forest dynamics using species-specific re-parameterizations. We applied this methodology to the two dominant pine species in the southeastern U.S., loblolly pine (Pinus taeda L.) and slash pine (Pinus elliotti). Specifically, we replaced unrealistic parameter values related to tree growth with physically meaningful parameters derived from publicly available remote-sensing products, field measurements, published literature, and expert knowledge. Outputs of the default and re-parameterized models were compared at four pine plantation sites across a range of management, soil, and climate conditions. Results were validated against MODIS-derived leaf area index (LAI) and evapotranspiration (ET), as well as field observations of total biomass. The re-parameterized model outperformed the default model in simulating LAI, biomass accumulation, and ET at all sites. The two parametrizations also resulted in substantially different mean annual water budgets for all sites, with reductions in water yield ranging from 13 to 45% under the new parameterization, highlighting the importance of properly parameterizing forest dynamics in watershed models. Importantly, our re-parameterization methodology does not require alteration to the SWAT code, allowing it to be readily adapted and applied in ongoing and future watershed modeling studies.

Improved agricultural Water management in data-scarce semi-arid watersheds: Value of integrating remotely sensed leaf area index in hydrological modeling

In watersheds located in semi-arid regions, vegetation dynamics, evapotranspiration (ET), and associated water and energy balances collectively play a major role in controlling hydrological regimes and crop yield. As such, it is challenging to predict the complex hydrological processes and biophysical dynamics. This challenge increases in areas with limited data availability. The key objective of this study was to evaluate the direct integration of remotely sensed Leaf Area Index (LAI) data into a hydrological model to improve streamflow, ET, and crop yield estimates. We also demonstrated how an improved model integrated with remotely sensed LAI data can inform water managers by predicting water productivity (WP) under different irrigation schemes. We took agricultural-dominated San Joaquin Watershed in California, United States, as our testbed and integrated the Moderate Resolution Imaging Spectroradiometer (MODIS) 500-m resolution 4-day total LAI data into the SWAT (Soil and Water Assessment Tool) model. Results showed that, compared to conventional SWAT model that relies on semi-empirical equations and user inputs for simulating biophysical processes, direct LAI integration into SWAT model (SWAT-LAI) notably captured the actual vegetation dynamics and improved ET and crop yield estimations. The WP simulated by the improved SWAT-LAI model for almond and grape yields varied within a range from 0.363 to 3.81 kg/m³ and 0.32 to 4.76 kg/m³ across different irrigation applications. The outcomes of this study showed that deficit irrigation application could be a viable option in water stressed regions, since it can save a substantial amount of irrigation water and maintain the higher water productivity required for both almond and grape yield production. This study shows an evidence of how remotely sensed data integrated into hydrological models can serve as a decision support tool by providing quantitative information on crop water use and crop production.

AB0694 IS THERE ANY HETEROGENEITY OF SPONDYLOARTHRITIS DISEASE MANIFESTATIONS BETWEEN TWO ETHNIC SUBGROUPS?:A MULTICENTRE INTERNATIONAL COMPARATIVE STUDY BETWEEN INDIA AND UK

Background:

Pathogenesis of Spondyloarthritis (SpA) multifactorial and remains unclear. Various hypothesis have been postulated genetics, HLAB27, IL17, Gut microbiome and Biomechanical stress. Many of these factors can be attributed to ethnic background and environment. HLAB27 accounts for 20–25 % of total heritability and 40% of genetic risk while <10% of HLA-B27 carriers in general population develop SpA1. Higher faecal calprotectin levels in SpA compared to control point towards microscopic gut inflammation2. Thus dietary habits and geographical factors can influence pathogenesis of disease. We looked in clinical manifestations of SpA patients of two very different ethnic background Caucasians and Indians from UK and India to shed more light in understanding the disease

Objectives:

To study any differences in the clinical manifestations of SpA patients of two ethnic groups

To compare outcome measure (BASDAI and ASDAS) between Caucasians and Indians

To study the difference in disease activity between Indian patients and British Asians

Methods:

Multicentre observation study where data of SpA patients attending rheumatology clinics from two major teaching hospitals collected. In India data collected from Sheth VS Hospital and NHL Medical College, Gujarat and in United Kingdom from University Hospitals Leicester, NHS trust. Leicester has a multi-ethnic demography wherein almost 30%3of population is of south Asian ethnicity, making this study unique.

Baseline demographic and clinical data was collected. Clinical and outcome measures compared to see any heterogeneity in disease manifestations. SPSS software used

Results:

Total 200 patients analysed with 148 Indians and 52 Caucasians. The Indian cohort was subdivided into British Asians (second generation Indians) and those form Gujarat, India

We found Indian subgroups were younger with shorter disease duration. Comparison in Table 1

Table 1.CaucasianIndianPAge45.9±1231±12<0.001M:F34:193:10.74TDI years9.6 ±5.93.5± 5.2<0.001BASDAI4.05±2.173.1±1.70.002ASDAS2±0.82.4±1.20.02CRP12.8±23.624±12<0.001HLAB2767%26%<0.001Uveitis25%12%0.02IBP78%90%0.03Enthesitis21%60%<0.001Peripheral Arthritis19%36%0.02Dactylitis2%10%0.07Psoriasis10%20%0.1IBD2%5%0.35Comparing British Asians to Indians, Gujarat no significant difference in clinical parameters. (Table 2)British AsianIndianPBASDAI5.16±2.763.1±1.70.006ASDAS2.53±1.32.4±1.20.74CRP15.2 ±15.424±12<0.001

Conclusion:

We found Caucasians had more HLAB27 positivity and extra-articular manifestation of uveitis however the Indian population has more enthesitis and peripheral arthritis. Enthesitis is initiated during a mechano-sensation and the cultural difference including style of footwear could probably be one of the factors explaining our findings inflammatory back pain has been reported to be higher in Indians compared to Caucasians which could be due to life style

The fact that ASDAS CRP behaves similarly in Indian patients across the two countries and is more when compared to Caucasians might point towards overall higher burden of disease in Indian population

To our knowledge this is a first study comparing clinical manifestations of SpA between Indians and Caucasians

References:

[1]Brown MAet al. Susceptibility to ankylosing spondylitis in twins: the role of genes, HLAand environment.Arthritis Rheum 1997;40: 1823–8

[2]J Simione, et al. Fecal Calprotectin, GutInflammation and SpA Archives of Medical Research. 2019;50:41-46

[3]http://www.ons.gov.uk/census

Disclosure of Interests:

Nibha Jain: None declared, Sapan Pandya: None declared, Puja Srivastava: None declared, Prashant Chotalia: None declared, Arumugam Moorthy Speakers bureau: Abbvie, Novartis,UCB,MSD

N8-Glycosylated 8-Azapurine and Methylated Purine Nucleobases: Synthesis and Study of Base Pairing Properties

In this report, we present the synthesis of N⁸-glycosylated 8-aza-2-methylhypoxanthine and 8-aza-6-thiohypoxanthine 2'-deoxynucleosides as well as methylated 2'-deoxynebularine derivatives. In vitro base pairing properties between each modified and canonical nucleobase were studied. As demonstrated by T_m, incorporation of the modified bases in DNA resulted, with few exceptions, in low stability of duplexes. Modified bases studied in this report are preferentially recognized by T (for N⁸-glycosylated 8-aza-2-methylhypoxanthine and methylated purines) and G (N⁸-glycosylated 8-aza-2-methylhypoxanthine). The base pair formed between N⁸-glycosylated 8-aza-6-thiohypoxanthine and N⁹-glycosylated 2-methyl-6-thiohypoxanthine (X2:X6) showed, to some extent, an orthogonal interaction. Based on T_m studies, the only potential self-pairing system is formed by the N⁸-glycosylated 8-aza-6-thiohypoxanthine nucleoside (X2) but only in the absence of canonical G and T. This study indicated that the canonical thymine base is the preferential base partner of methylated purine bases.

P2448Evolution of clinical quality activities within a national echocardiography database: seven-year trends from the GenesisCare Outcomes Registry

Introduction

Despite rapid technologic advances and sustained growth, less attention has been focused on quality in imaging than in other areas of cardiovascular medicine. To address this deficit, the ACC proposed additional areas of effort such as data standardisation, structured reporting identifying key data elements and imaging registries. We explored these changes within a large multi-centre Australian registry.

Methods

From 2010–2014 we introduced direct online entry of echocardiographic studies into an electronic database, selection and auditing of key data elements and quality improvement pathways to maximise completeness of data acquisition and reporting across 4 states. We compared completeness of key data elements (AV peak velocity, EF, E/E', LA area, rhythm, RVSP) by time and state using de-identified data.

Results

464,688 echocardiographic procedures were captured from 2011 to 2018.

Data completeness improved significantly from 2011 to 2018 (72.0±26.8 vs 88.2±13.5%, p=0.02). Inter-practice variability fell from 2011 to 2018 for both EF and E/E', p<0.002

Conclusion

Identification, systematic capture and auditing of key echo data elements can significantly improve the quality and reduce inter-practice variability of echo data. Developing a national database allows rapid adoption of local quality improvements.

Acknowledgement/Funding

None

P6309Impaired secretion of clusterin in pericardial fluid of diabetics, a deleterious outcome for the cardiac micro-vasculature

Background

Extracellular vesicles are vital mediators of cell-to-cell communications. We previously demonstrated that in the adult heart, exosomes released in the pericardial fluid (PF) have the functional capability to induce cell survival and angiogenesis in recipient endothelial cells. It has previously been shown that PF exosomes from patients with an existing myocardial infarction (MI) contain clusterin (CLU). Remarkably, secreted CLU is cardio-protective as evidenced by enhanced arteriogenesis and reduced apoptosis in animal models of MI. We hypothesize that type 2 Diabetes Mellitus (T2DM) along with ischemic heart disease (IHD) alters PF EV content impairing its reparative angiogenic potential.

Aim

To investigate the role of T2DM in modulating human PF exosomal content and its vascular action.

Methods and results

PF samples were collected from 3 different groups of patients (N=3): 1) Ischemic heart disease (IHD) with or 2) without T2DM, and 3) non-ischaemic, non-diabetic controls operated for mitral valve repair.

The impact of PF exosomes on human coronary microvascular ECs (HCMECs) was evaluated by cell based functional assays for measuring apoptosis, proliferation and angiogenesis. Interestingly, unlike PF exosomes from control patients, PF exosomes from DM patients with IHD promoted EC apoptosis and impaired angiogenesis.

To investigate the effect of T2DM on PF content, we performed high throughput proteomic and metabolomic analysis of whole PF and PF EVs. We identified proteins and metabolites that were differentially expressed under T2DM condition by using the R package Limma. Employing a network approach, protein and metabolic data were integrated by using our newly developed inhouse R package Metabosignal. This networks approach revealed an interesting interaction circuit involving protein CLU. The T2DM-associated reduction of CLU level in the PF, identified from the “omics” analyses was confirmed by ELISA (n=8 patients per group).

To examine the effects of DM and ischemia on CLU intracellular expression and secretion, HCMECs were exposed to high D-glucose (HG, 25 mM) and hypoxia (1%O2). In line with our PF data, HCMECs exposed to HG and hypoxia showed lower levels of both CLU mRNA and secreted CLU (ELISA). Importantly, recombinant CLU (rCLU) treatment on HCMECs rescued their angiogenic potential, induced cell proliferation and protected them from apoptosis under both HG and hypoxia conditions. In addition, silencing of endogenous levels of CLU in HCMECs impaired angiogenesis, suggesting that CLU might be an inherent component of the angiogenesis machinery in ECs.

Conclusions

This study suggests that DM reduces the level of secreted CLU in the PF, depriving myocardial micro-vessels of this protective and regenerative mediator. Restoring diminished CLU levels in the diabetic heart could be a possible therapeutic approach for contrasting diabetic micro-angiopathy.

Acknowledgement/Funding

British Heart Foundation Program Grant

P3465Inducible left ventricular outflow tract obstruction is associated with a higher incidence of perioperative cardiac arrest in liver transplantation

Background

Inducible left ventricular outflow tract obstruction (LVOTO) is not infrequently encountered in liver transplant (LT) candidates undergoing cardiac workup. While the impact of LVOTO on adverse cardiovascular haemodynamics is well reported, it is unclear whether it predisposes to perioperative cardiovascular complications following LT.

Purpose

To investigate the effect of inducible left ventricular outflow tract obstruction on perioperative cardiovascular complications in a modern cohort of liver transplant patients.

Methods

Consecutive patients undergoing dobutamine stress echocardiography (DSE) were evaluated from a quaternary LT centre between 2010 and 2017. Inducible LVOTO was defined as LVOT gradient ≥36mmHg. Perioperative major adverse cardiovascular events (MACE) at 30 days and all-cause death were recorded from a prospectively maintained transplantation database and augmented by electronic medical record review.

Results

We evaluated 560 patients who underwent DSE as part of a workup for LT. Of these, 319 progressed to transplant. Inducible LVOTO was observed in 68 patients (21.3%). A higher baseline cardiac output (7.7 L/min vs 7.0 L/min, p=0.002) predicted for development of inducible LVOTO. Seventy-seven patients (4.1%) experienced a MACE including five deaths, 19 cases of heart failure, 11 cardiac arrests, 10 acute coronary syndromes and 46 cases of arrhythmias (VT/AF). Overall MACE occurred in 17/68 patients (25.0%) with LVOTO and 60/251 patients (23.9%) without LVOTO (p=0.85). However, there was a significantly increased risk of resuscitated perioperative cardiac arrest in patients with LVOTO (7.4% vs 2.4%, p=0.04). Patients with LVOTO also required significantly greater volumes of fluid intra-operatively (8.37L vs. 6.71L, p=0.043).

Cardiac Arrest in LT Patients with LVOTO

Conclusions

Inducible LVOTO is a frequent finding occurring in 21.3% of LT candidates. Despite higher intraoperative fluid resuscitation, LVOTO increased the risk of a perioperative cardiac arrest. Further studies are required to confirm these findings and to assess whether patients with LVOTO undergoing liver transplantation may benefit from heightened perioperative surveillance.

Massive Spontaneous Hemothorax as a Complication of Apixaban Treatment

INTRODUCTION

Hemothorax is usually related to chest or iatrogenic trauma from procedures such as central lines and thoracentesis. Spontaneous hemothorax is defined as pleural fluid hematocrit greater than 50% of serum hematocrit in absence of natural or iatrogenic trauma affecting the lung or pleural space. Coagulopathy secondary to anticoagulant use has been associated with spontaneous hemothorax. We present a case of spontaneous hemothorax in a patient taking apixaban for venous thromboembolism disease. To our knowledge, this is the first case report of apixaban as a cause of spontaneous hemothorax.

CASE PRESENTATION

A 56-year-old woman with end-stage renal disease (ESRD) was diagnosed with upper extremity deep vein thrombosis (DVT) one month prior to presentation and was started on apixaban presented with dyspnea and left-sided pleuritic chest pain for two weeks. She was found to have left-sided large pleural effusion which was diagnosed as hemothorax. Other etiologies for spontaneous hemothorax were excluded and drainage by 12-French pigtail catheter achieved total resolution of hemothorax in three days.

DISCUSSION

Apixaban is a DOAC used to prevent stroke or thromboembolic events in patients with nonvalvular atrial fibrillation and to prevent recurrent venous thromboembolic disease. Events such as gastrointestinal, intracranial, and soft tissue bleeding have been well-documented. However, bleeding manifestation as hemothorax is seldom reported. Our patient presented with isolated left-sided large pleural effusion which was diagnosed as spontaneous hemothorax. 12-Fr pigtail catheter drainage was effective in the management of our patient and provided total resolution in three days.

CONCLUSION

Spontaneous hemothorax is a rare complication of anticoagulant therapy and might not exhibit the usual radiological signs of traumatic hemothorax. Health care providers should have high index of suspicion for spontaneous hemothorax when evaluating new pleural effusion in patients receiving DOACs therapy. Drainage by small bore pigtail catheter might be as effective as larger chest tubes.

Outcomes in juvenile onset lupus: single center cohort from a developing country

Introduction

About 10–20% of systemic lupus erythematosus (SLE) patients have onset in childhood and have more severe organ involvement. Survival of juvenile SLE patients is improving worldwide. Long-term data of childhood onset SLE from developing countries is scarce.

Methods

Clinical and laboratory data at initial presentation and follow-up visits were retrieved from clinic files, hospital information system and personal interviews. Treatment received, complications, flares, outcomes and death were recorded. Survival was calculated using Kaplan–Meier survival curves and regression analysis was done for predictors of mortality.

Results

Children with SLE ( n = 273, 250 girls) had a median age at onset of 14 years and duration of illness prior to diagnosis at our hospital of 1 year. Fever and arthritis were the most common presenting manifestations. Renal disease was seen in 60.5% and central nervous system (CNS) disease in 29%. The median follow-up period in 248 patients was 3.5 years. Fourteen children died, and 10 of these had active disease at the time of death. The mean actuarial survival was 24.5 years and survival rates at 1, 5 and 10 years were 97.9%, 95% and 89% respectively. Fever, CNS disease, anti-dsDNA levels and serious infections predicted death on univariate and multivariate analysis. Infections were seen in 72 children (26.3%), and 38 of these infections were serious. One-third of the patients had damage on the last follow-up. Flares were seen in 120 children, the majority being major flares.

Conclusion

Outcomes of pediatric SLE in North Indian children are similar to those seen in developed countries. Infections pose a major challenge in these patients.

Mutant Variants of the Substrate-Binding Protein DppA from Escherichia coli Enhance Growth on Nonstandard γ-Glutamyl Amide-Containing Peptides

The import of nonnatural molecules is a recurring problem in fundamental and applied aspects of microbiology. The dipeptide permease (Dpp) of Escherichia coli is an ABC-type multicomponent transporter system located in the cytoplasmic membrane, which is capable of transporting a wide range of di- and tripeptides with structurally and chemically diverse amino acid side chains into the cell. Given this low degree of specificity, Dpp was previously used as an entry gate to deliver natural and nonnatural cargo molecules into the cell by attaching them to amino acid side chains of peptides, in particular, the γ-carboxyl group of glutamate residues. However, the binding affinity of the substrate-binding protein dipeptide permease A (DppA), which is responsible for the initial binding of peptides in the periplasmic space, is significantly higher for peptides consisting of standard amino acids than for peptides containing side-chain modifications. Here, we used adaptive laboratory evolution to identify strains that utilize dipeptides containing γ-substituted glutamate residues more efficiently and linked this phenotype to different mutations in DppA. In vitro characterization of these mutants by thermal denaturation midpoint shift assays and isothermal titration calorimetry revealed significantly higher binding affinities of these variants toward peptides containing γ-glutamyl amides, presumably resulting in improved uptake and therefore faster growth in media supplemented with these nonstandard peptides.IMPORTANCE Fundamental and synthetic biology frequently suffer from insufficient delivery of unnatural building blocks or substrates for metabolic pathways into bacterial cells. The use of peptide-based transport vectors represents an established strategy to enable the uptake of such molecules as a cargo. We expand the scope of peptide-based uptake and characterize in detail the obtained DppA mutant variants. Furthermore, we highlight the potential of adaptive laboratory evolution to identify beneficial insertion mutations that are unlikely to be identified with existing directed evolution strategies.

Secretome of Differentiated PC12 Cells Restores the Monocrotophos-Induced Damages in Human Mesenchymal Stem Cells and SHSY-5Y Cells: Role of Autophagy and Mitochondrial Dynamics

A perturbed cellular homeostasis is a key factor associated with xenobiotic exposure resulting in various ailments. The local cellular microenvironment enriched with secretory components aids in cell-cell communication that restores this homeostasis. Deciphering the underlying mechanism behind this restorative potential of secretome could serve as a possible solution to many health hazards. We, therefore, explored the protective efficacy of the secretome of differentiated PC12 cells with emphasis on induction of autophagy and mitochondrial biogenesis. Monocrotophos (MCP), a widely used neurotoxic organophosphate, was used as the test compound at sublethal concentration. The conditioned medium (CM) of differentiated PC12 cells comprising of their secretome restored the cell viability, oxidative stress and apoptotic cell death in MCP-challenged human mesenchymal stem cells and SHSY-5Y, a human neuroblastoma cell line. Delving further to identify the underlying mechanism of this restorative effect we observed a marked increase in the expression of autophagy markers LC3, Beclin-1, Atg5 and Atg7. Exposure to autophagy inhibitor, 3-methyladenine, led to a reduced expression of these markers with a concomitant increase in the expression of pro-apoptotic caspase-3. Besides that, the increased mitochondrial fission in MCP-exposed cells was balanced with increased fusion in the presence of CM facilitated by AMPK/SIRT1/PGC-1α signaling cascade. Mitochondrial dysfunctions are strongly associated with autophagy activation and as per our findings, cellular secretome too induces autophagy. Therefore, connecting these three potential apices can be a major breakthrough in repair and rescue of xenobiotic-damaged tissues and cells.

Synthesis and antiviral evaluation of cyclopentyl nucleoside phosphonates

The synthesis of both 2'-hydroxy-3'-deoxy and 2'-deoxy-3'-hydroxy cyclopentyl nucleoside phosphonates with the natural nucleobases adenine, thymine, cytosine and guanine from a single precursor has been performed. The guanine containing analogues showed antiviral activity. Especially the 3'-deoxy congener 23 was active, displaying an EC₅₀ of 5.35 μM against TK⁺ VZV strain and an EC₅₀ of 8.83 μM against TK^- VZV strain, besides lacking cytotoxicity. However, the application of phosphonodiamidate prodrug strategy did not lead to a boost in antiviral activity.

Effect of immobilisation on production of rapamycin by Streptomyces hygroscopicus

Numerous antibiotics as secondary metabolites have been isolated from microbes specifically Streptomyces sp. Rapamycin is one of these, which exhibits many roles as immunosuppressant, antifungal antibiotic, anti-tumour etc. Constant thrust has been put by many researchers to improve the production of rapamycin by Streptomyces hygroscopicus. Past research show that whole cell immobilisation is a useful strategy for antibiotic production with economical advantage. This study is another attempt in this direction which involves immobilisation of producer organism on various supports such as polyutherane foam, sintered beads, glass beads and foam peanuts. These support materials have been selected based on their availability and were pre-treated chemically to improve their adsorption capacity. Comparative profiles have been studied to identify the most suited support for the growth of Streptomyces sp. Variation of biomass immobilisation on various support materials with respect to time in batch culture was studied. Cell release study for the carriers was carried out in production medium to evaluate the performance of beads. Also, scanning electron microscopy (SEM) has been employed for visualisation and analysis of immobilised biomass and measurement of pore size. This study aims to determine a suitable support for immobilisation of Streptomyces hygroscopicus which could be used for rapamycin production in batch and continuous mode.

A novel heterozygous missense mutation in uromodulin gene in an Indian family with familial juvenile hyperuricemic nephropathy

Familial juvenile hyperuricemic nephropathy (FJHN), characterized by early-onset hyperuricemia, reduced fractional excretion of uric acid, and chronic renal failure is caused due to mutation in uromodulin (UMOD) gene. We identified a novel mutation in a family with multiple members affected with FJHN. Ten coding exons of UMOD gene in three family members with clinical and biochemical features of FJHN and one unaffected family member were sequenced, and sequence variants were analyzed for the pathogenicity by bioinformatics studies. A heterozygous novel missense mutation (c. 949 T >G) in exon 5 leading to the replacement of cysteine by glycine at position 317 was identified in all three affected family members. This mutation has not been reported earlier in Human Gene Mutation Database, Human Genome Variation, Clinvar, and 1000 Genome. The mutation lies in the cysteine-rich 2 domain of the protein, and the affected residue is evolutionary conserved in other species. To our knowledge, this is the first report of the identification of UMOD mutation in an Indian family.

Incorporation of Amino Acids with Long-Chain Terminal Olefins into Proteins

The increasing need for site-specific protein decorations that mimic natural posttranslational modifications requires access to a variety of noncanonical amino acids with moieties enabling bioorthogonal conjugation chemistry. Here we present the incorporation of long-chain olefinic amino acids into model proteins with rational variants of pyrrolysyl-tRNA synthetase (PylRS). Nε-heptenoyl lysine was incorporated for the first time using the known promiscuous variant PylRS(Y306A/Y384F), and Nε-pentenoyl lysine was incorporated in significant yields with the novel variant PylRS(C348A/Y384F). This is the only example of rational modification at position C348 to enlarge the enzyme's binding pocket. Furthermore, we demonstrate the feasibility of our chosen amino acids in the thiol-ene conjugation reaction with a thiolated polysaccharide.

Unraveling The Origin of Enhanced Field Emission from Irradiated FeCo-SiO2 Nanocomposites: A Combined Experimental and First-Principles Based Study

This work is driven by the vision of engineering planar field emitters with ferromagnetic metal-insulator nanocomposite thin films, using swift heavy ion (SHI) irradiation method. FeCo nanoparticles inside SiO2 matrix, when subjected to SHI get elongated. Using this, we demonstrate here a planar field emitter with maximum current density of 550 μA/cm(2) at an applied field of 15 V/μm. The film, irradiated with 5 × 10(13) ions/cm(2) fluence (5e13) of 120 MeV Au(9+) ions, shows very high electron emitting quantum efficiency in comparison to its unirradiated counterpart. Surface enhanced Raman spectroscopy analysis of unirradiated and 5e13 films further confirms that the field emission (FE) enhancement is not only due to surface protrusions but also depends on the properties of entire matrix. We find experimental evidence of enhanced valence band density of states (VB DOS) for 5e13 film from XPS, which is verified in the electronic structure of a model FeCo cluster from first-principles based calculations combining density functional theory (DFT) and molecular dynamics (MD) simulations. The MD temperature is selected from the lattice temperature profile inside nanoparticles as deduced from thermal spike model. Increasing the irradiation fluence beyond 5e13, results in reduced VB DOS and melting of surface protrusions, thus causing reduction of FE current density. We finally conclude from theoretical analysis that change in fluence alters the co-ordination chemistry followed by the charge distribution and spin alignment, which influence the VB DOS and concurrent FE as evident from our experiment.