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.

Biostimulation of jarosite and iron oxide-bearing mine waste enhances subsequent metal recovery

Novel resource recovery technologies are required for metals-bearing hazardous wastes in order to achieve circular economy outcomes and industrial symbiosis. Iron oxide and co-occurring hydroxysulphate-bearing wastes are globally abundant and often contain other elements of value. This work addresses the biostimulation of indigenous microbial communities within an iron oxide/ hydroxysulphate-bearing waste and its effect on the subsequent recoverability of metals by hydrochloric, sulphuric, citric acids, and EDTA. Laboratory-scale flow-through column reactors were used to examine the effect of using glycerol (10% w/w) to stimulate the in situ microbial community in an iron oxide/ hydroxysulphate-bearing mine waste. The effects on the evolution of leachate chemistry, changes in microbiological community, and subsequent hydrometallurgical extractability of metals were studied. Results demonstrated increased leachability and selectivity of Pb, Cu, and Zn relative to iron after biostimulation with a total of 0.027 kg of glycerol per kg of waste. Biostimulation, which can be readily applied in situ, potentially opens new routes to metal recovery from globally abundant waste streams that contain jarosite and iron oxides.

Towards passive bioremediation of dye-bearing effluents using hydrous ferric oxide wastes: Mechanisms, products and microbiology

A novel, circular economy-inspired approach for the "passive" (non-powered and reagent-free) treatment of dye-bearing effluent is presented. The treatment utilises the biogeochemical interaction of dye-bearing wastewater with hydrous ferric oxide (HFO) bearing sludges. The work presented demonstrates for the first time the reuse of HFO-rich waste sludges from potable water and mine water treatment. The waste was used directly without modification or reagent addition, as media/substrate in simple flow-through reactors for the decolourisation and biodegradation of methyl orange (MO) and mixed dyes textile effluent. Three phases of exploratory proof of concept work were undertaken. Columns containing HFO sludges were challenged with solution of MO, and MO amended with glycerol (Phase I), MO in a synthetic textile effluent recipe (Phase II), and real mixed textile effluent containing a mixture of dyes (Phase III). After an initial lag period extensive decolourisation of dye was observed in all cases at rates comparable with pure strains and engineered bioreactor processes, with evidence of biodegradation beyond simple cleavage of the mono azo chromophore and mineralisation. The microbiology of the initial sludge samples in both cases exhibited a diverse range of iron oxidising and reducing bacteria. However, post experiment the microbiology of sludge evolved from being dominated by Proteobacteria to being dominated by Firmicutes. Distinct changes in the microbial community structure were observed in post-treatment MWTS and WTWS where genera capable of iron and sulphate reduction and/or aromatic amine degradation were identified. Average nitrogen removal rates for the columns ranged from 27.8 to 194 g/m³/day which is higher than engineered sequential anaerobic-aerobic bioreactor. Postulated mechanisms for the fast anaerobic decolourisation, biodegradation, and mineralisation of the dyes (as well nitrogen transformations) include various direct and indirect enzymatic and metabolic reactions, as well as reductive attack by continuously regenerated reductants such as Fe(II), HFO bound Fe(II), FeS, and HS^-. The ability of iron reducers to degrade aromatic rings is also considered important in the further biodegradation and complete mineralisation of organic carbon. The study reveals that abundant and ubiquitous HFO-rich waste sludges, can be used without amendment, as a substrate in simple flow-through bioremediation system for the decolourisation and partial biodegradation of dyes in textile effluent.

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

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.

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.

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.

Fluorescent Lead(IV) Sulfide Nanoparticles Synthesized by Idiomarina sp. Strain PR58-8 for Bioimaging Applications

The fabrication of nanoparticles by microorganisms presents a "green" method for generating biocompatible nanomaterials. We discovered the intracellular biosynthesis of fluorescent lead(IV) sulfide nanoparticles by the moderate halophile, Idiomarina sp. strain PR58-8. The bacterium tolerated up to 8 mM Pb(NO3)2 during growth. Non-protein thiols dose-dependently increased in response to metal exposure, which suggests they are involved in the growth of PbS2 crystals and lead detoxification. Using X-ray diffraction, transmission electron microscopy (TEM), high-resolution TEM, and energy dispersive analysis of X-rays, the nanoparticles were characterized as spherical β-PbS2 nanoparticles (PbS2NPs) with a tetragonal crystal lattice, a crystallite domain size of 2.38 nm, and an interplanar distance of 0.318 nm. A narrow symmetric emission spectrum with a Gaussian distribution and an emission maximum at 386 nm was obtained when the particles were excited at 570 nm. The PbS2NPs exhibited a large Stokes' shift (8,362 cm-1) and a relatively high quantum yield (67%). These properties, along with fluorescence that was maintained in various microenvironments and their biocompatibility, make these nanoparticles excellent candidates for bioimaging. The particles were internalized by HeLa cells and evenly distributed within the cytoplasm, exhibiting their potential for in situ bioimaging applications. The "as-synthesized" lead(IV) sulfide nanoparticles may provide expanded opportunities for targeted bioimaging via modifying the surface of the particles.IMPORTANCE This article reports the intracellular synthesis of fluorescent lead(IV) sulfide nanoparticles (PbS2NPs) by a microorganism. All previous reports on the microbial synthesis of lead-based nanoparticles are on lead(II) sulfide that exhibits near-infrared fluorescence, requiring expensive instrumentation for bioimaging. Bioimaging using PbS2NPs can be achieved using routine epifluorescence microscopes, as it fluoresces in the visible range. The research on PbS2 nanoparticles to date is on their chemical synthesis employing toxic precursors, extreme pH, pressure, and temperature, resulting in cytotoxic products. In this context, the synthesis of PbS2 nanoparticles by Idiomarina sp. strain PR58-8, described in this work, occurs at ambient temperature and pressure and results in the generation of biocompatible nanoparticles with no hazardous by-products. The excellent fluorescence properties that these particles exhibit, as well as their abilities to easily penetrate the cells and evenly distribute within the cytoplasm, make them exceptional candidates for bioimaging applications. This study demonstrated the synthesis and fluorescence bioimaging application of microbially synthesized PbS2 nanoparticles.

Biomarkers of Ionizing Radiation Exposure: A Multiparametric Approach

Humans are exposed to ionizing radiation not only through background radiation but also through the ubiquitous presence of devices and sources that generate radiation. With the expanded use of radiation in day-to-day life, the chances of accidents or misuse only increase. Therefore, a thorough understanding of the dynamic effects of radiation exposure on biological entities is necessary. The biological effects of radiation exposure on human cells depend on much variability such as level of exposure, dose rate, and the physiological state of the cells. During potential scenarios of a large-scale radiological event which results in mass casualties, dose estimates are essential to assign medical attention according to individual needs. Many attempts have been made to identify biomarkers which can be used for high throughput biodosimetry screening. In this study, we compare the results of different biodosimetry methods on the same irradiated cells to assess the suitability of current biomarkers and push forward the idea of employing a multiparametric approach to achieve an accurate dose and risk estimation.

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.

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.

Outcome of lupus nephritis in childhood onset SLE in North and Central India: single-centre experience over 25 years

INTRODUCTION

Childhood SLE (cSLE) has a higher prevalence of lupus nephritis (LN), and there are ethnic variations in response to treatment as well as outcome of LN. There are limited data on long-term outcome of LN in cSLE from the Indian subcontinent.

METHODS

Retrospective analysis of case records of patients with cSLE (satisfying revised American College of Rheumatology (ACR) 1997 criteria for diagnosis) and age of onset <18 years was conducted from 1989 to 2013. Data on clinical features, renal involvement and biopsy findings, treatment, renal outcome, damage accrual and mortality were collected. End-stage renal disease (ESRD) was defined as the need for renal replacement therapy. Actuarial ESRD-free survival was studied as the primary outcome measure using Kaplan-Meier analysis.

RESULTS

Among 205 children with cSLE, 134 (121 girls) had evidence of LN. The mean age at disease onset was 13.7 ± 3.5 years and the mean disease duration at presentation was 1.9 ± 2.5 years. Kidney biopsy was available for 92 patients, and histology included: 13 (14.2%) Class II, 24 (26%) Class III, 43 (46.7%) Class IV and 12 (13.1%) Class V LN. The mean follow-up period was 6.75 ± 5.7 years. At last visit, 81 (60.4%) children were in complete remission, 28 (20.9%) were in partial remission, 15 (11.2%) still had active nephritis and 10 (7.4%) had progressed to ESRD. Almost two-thirds (62.9%) of patients experienced lupus flares, and mean flare rate was 0.09 flares/patient follow-up year. Fifty-six (43.8%) children accrued damage and the mean Systemic Lupus International Collaborating Clinics (SLICC)/ACR damage score was 0.79 ± 1.13. Actuarial ESRD-free survival at five, 10 and 15 years was 91.1%, 79% and 76.2%, and five-, 10- and 15-year renal survival was 93.8%, 87.1% and 84%, respectively. Although multiple factors individually predicted poor outcome (death/ESRD), only raised serum creatinine at onset (R square = 0.65, p ≤ 0.0001) and damage accrual (R square = 0.62, p ≤ 0.0001) remained significant on multivariate analysis. Eleven (8.2%) children died during the follow-up period, and infections were the leading cause of mortality.

CONCLUSIONS

Long-term outcome of LN in cSLE in our cohort was better than previous reports from India. However, a high rate of major infection still remains the leading cause of mortality.

Nanomaterial-Based Approaches for Prevention of Biofilm-Associated Infections on Medical Devices and Implants

Biofilm formation is a major problem in medical device-related infections leading to failure of implant-based therapies. Though various conventional approaches to counter biofilm formation like physical and/or mechanical removal, chemical removal, and the use of antimicrobials exist, they fail due to increased resistance of biofilms. This review discusses various nanomaterial-based approaches such as the use of metallic and metal oxide nanoparticles- and polymer-based nanocomposites, which are currently being developed for prevention and treatment of biofilms. Nanoparticles of transition metals and their oxides are toxic to microorganisms and exhibit their toxicity through the generation of reactive oxygen species at concentrations that are non-toxic to eukaryotic cells. Other approaches include the entrapment of bioactive agents in polymer/ceramic nanoparticles, for enhanced anti-biofilm activity due to the synergistic effect between them. These nanomaterial-based approaches could play an important role in control and eradication of biofilm related infections and complications associated with medical devices and implants.

Anti-bacterial TeNPs biosynthesized by haloarcheaon Halococcus salifodinae BK3

Microbial synthesis of highly structured metal sulfide and metallic nanoparticles is a benign approach of nanomaterial synthesis. Various microbes have been exploited for nanoparticle synthesis, but nanofabrication using haloarchaea is still in nascent stages. Here, we report the intracellular synthesis of hexagonal needle-shaped tellurium nanoparticles with an aspect ratio of 1:4.4, by the haloarcheon Halococcus salifodinae BK3. The isolate was able to tolerate up to 5.5 mM K2TeO3. The yield of tellurium nanoparticles was highest when the culture was exposed to 3 mM K2TeO3, even though the isolate exhibited slightly decreased growth rate as compared to the culture growing in the absence of K2TeO3. The enzyme tellurite reductase was responsible for tellurite resistance and nanoparticle synthesis in H. salifodinae BK3. These tellurium nanoparticles exhibited anti-bacterial activities against both Gram-positive and Gram-negative bacteria, with higher antibacterial activity towards Gram-negative bacteria. This is the first report on the synthesis of tellurium nanoparticles by Halophilic archaea.

Achiral, acyclic nucleic acids: synthesis and biophysical studies of a possible prebiotic polymer

The search for prebiotic, nucleic acid precursors is, at its best, a speculative undertaking.