Microfluidic viscometer by acoustic streaming transducers.

Measurement of fluid viscosity represents a huge need for many biomedical and materials processing applications. Sample fluids containing DNA, antibodies, protein-based drugs, and even cells have become important therapeutic options. The physical properties, including viscosity, of these biologics are critical factors in the optimization of the biomanufacturing processes and delivery of therapeutics to patients.

N-Detected TROSY NMR experiments to study large disordered proteins in high-field magnets.

Intrinsically disordered regions (IDRs) of proteins are critical in the regulation of biological processes but difficult to study structurally. Nuclear magnetic resonance (NMR) is uniquely equipped to provide structural information on IDRs at atomic resolution; however, existing NMR methods often pose a challenge for large molecular weight IDRs. Resonance assignment of IDRs using N-detection was previously demonstrated and shown to overcome some of these limitations.

Clinical Profile of Coronavirus Disease 2019 Comparing the First and Second Waves: A Single-Center Study from North India.

Background And Objectives: Severe acute respiratory syndrome coronavirus 2, caused by the novel coronavirus disease 2019 (COVID-19), led to a devastating pandemic that hit majority of the countries globally in a wave-like pattern. The characteristics of the disease varied in different geographical areas and different populations. This study highlights the epidemiological and clinical characteristics of COVID-19 during two major waves in North India.

Various Factors that are Causing Difference in Prevalence of Coronary Risk Factors among Siblings.

Background And Aim: Coronary artery disease (CAD) is one of the predominant types of cardiovascular disease (CVD). The aim of present study was to study various factors that are causing difference in prevalence of coronary risk factors among siblings.

Materials And Methods: This cross-sectional study was conducted in Dayanand Medical College and Hospital, among the healthy individuals (not known CAD) attending regular health care outpatient department (OPD) and their siblings over a period of 1½ years.

Diabetes Mellitus Increases the Risk of Significant Hepatic Fibrosis in Patients With Non-alcoholic Fatty Liver Disease.

Background: Diabetes mellitus is associated with an increased risk of development of non-alcoholic fatty liver disease (NAFLD). However, the risk posed by diabetes mellitus in progression of liver disease is uncertain. This study compared the severity of hepatic fibrosis in patients with NAFLD with and without diabetes mellitus.

Anemia and Nutritional Status in Tuberculosis Patients.

Introduction: Anemia is a common complication of pulmonary tuberculosis (TB). Nutritional deficiency and malabsorption syndrome can deepen the severity of anemia. The aim of the present study was to study anemia and nutritional status in patients with TB at a tertiary care center.

Local Deuteration Enables NMR Observation of Methyl Groups in Proteins from Eukaryotic and Cell-Free Expression Systems.

Therapeutically relevant proteins such as GPCRs, antibodies and kinases face clear limitations in NMR studies due to the challenges in site-specific isotope labeling and deuteration in eukaryotic expression systems. Here we describe an efficient and simple method to observe the methyl groups of leucine residues in proteins expressed in bacterial, eukaryotic or cell-free expression systems without modification of the expression protocol. The method relies on simple stereo-selective C-labeling and deuteration of leucine that alleviates the need for additional deuteration of the protein.

Alkyne-Bridged α-Conotoxin Vc1.1 Potently Reverses Mechanical Allodynia in Neuropathic Pain Models.

Several -derived venom peptides are promising lead compounds for the management of neuropathic pain, with α-conotoxins being of particular interest. Modification of the interlocked disulfide framework of α-conotoxin Vc1.1 has been achieved using on-resin alkyne metathesis.

Chemoradiation in locally advanced Ca Cx: Effect on NGAL levels.

Introduction: Neutrophil gelatinase-associated lipocalin (NGAL) has been reported to be unregulated in many cancers and to suppress tumor suppressor genes like p53 leading to cell proliferation. Studies to report its relationship with carcinoma cervix (Ca Cx) are still scant.

Materials And Methods: Serum NGAL levels were analyzed in 30 patients of histopathologically proven locally advanced Ca Cx at the time of diagnosis and 3 weeks after standard chemoradiation by enzyme-linked immunosorbent assay.

Aromatic F-C TROSY: a background-free approach to probe biomolecular structure, function, and dynamics.

Atomic-level information about the structure and dynamics of biomolecules is critical for an understanding of their function. Nuclear magnetic resonance (NMR) spectroscopy provides unique insights into the dynamic nature of biomolecules and their interactions, capturing transient conformers and their features. However, relaxation-induced line broadening and signal overlap make it challenging to apply NMR spectroscopy to large biological systems.

Hypocalcemia Presenting as Life Threatening Torsades de Pointes with Prolongation of QTc Interval.

Torsades de pointes with prolonged QTc interval is a form of ventricular tachycardia. Many predisposing factors have been identified and hypocalcemia is among the rare ones. Our case illustrates that though rare, hypocalcemia might manifest as torsades de pointes with prolongation of QTc interval.

N detection harnesses the slow relaxation property of nitrogen: Delivering enhanced resolution for intrinsically disordered proteins.

Studies over the past decade have highlighted the functional significance of intrinsically disordered proteins (IDPs). Due to conformational heterogeneity and inherent dynamics, structural studies of IDPs have relied mostly on NMR spectroscopy, despite IDPs having characteristics that make them challenging to study using traditional H-detected biomolecular NMR techniques. Here, we develop a suite of 3D N-detected experiments that take advantage of the slower transverse relaxation property of N nuclei, the associated narrower linewidth, and the greater chemical shift dispersion compared with those of H and C resonances.

8-Mercaptoguanine Derivatives as Inhibitors of Dihydropteroate Synthase.

Dihydropteroate synthase (DHPS) is an enzyme of the folate biosynthesis pathway, which catalyzes the formation of 7,8-dihydropteroate (DHPt) from 6-hydroxymethyl-7,8-dihydropterin pyrophosphate (DHPPP) and para-aminobenzoic acid (pABA). DHPS is the long-standing target of the sulfonamide class of antibiotics that compete with pABA. In the wake of sulfa drug resistance, targeting the structurally rigid (and more conserved) pterin site has been proposed as an alternate strategy to inhibit DHPS in wild-type and sulfa drug resistant strains.

Distribution and kinetics of the Kv1.3-blocking peptide HsTX1[R14A] in experimental rats.

The peptide HsTX1[R14A] is a potent and selective blocker of the voltage-gated potassium channel Kv1.3, which is a highly promising target for the treatment of autoimmune diseases and other conditions. In order to assess the biodistribution of this peptide, it was conjugated with NOTA and radiolabelled with copper-64.

Reinvestigation of the biological activity of d-allo-ShK protein.

ShK toxin from the sea anemone is a 35-residue protein that binds to the Kv1.3 ion channel with high affinity. Recently we determined the X-ray structure of ShK toxin by racemic crystallography, in the course of which we discovered that d-ShK has a near-background IC value ∼50,000 times lower than that of the l-ShK toxin.

Structure and activity of contryphan-Vc2: Importance of the d-amino acid residue.

In natural proteins and peptides, amino acids exist almost invariably as l-isomers. There are, however, several examples of naturally-occurring peptides containing d-amino acids. In this study we investigated the role of a naturally-occurring d-amino acid in a small peptide identified in the transcriptome of a marine cone snail.

Stereoselective synthesis and structural elucidation of dicarba peptides.

A facile stereoselective synthesis of cis and trans unsaturated dicarba peptides has been established using preformed diaminosuberic acid derivatives as bridging units. In addition, characteristic spectral differences in the (13)C-NMR spectra of the cis- and trans-isomers show that the chemical shift of carbons in the Δ4,5-diaminosuberic acid residue can be used to assign stereochemistry in unsaturated dicarba peptides formed from ring closing metathesis of linear peptide sequences.

Structural Basis for the Inhibition of Voltage-gated Sodium Channels by Conotoxin μO§-GVIIJ.

Cone snail toxins are well known blockers of voltage-gated sodium channels, a property that is of broad interest in biology and therapeutically in treating neuropathic pain and neurological disorders. Although most conotoxin channel blockers function by direct binding to a channel and disrupting its normal ion movement, conotoxin μO§-GVIIJ channel blocking is unique, using both favorable binding interactions with the channel and a direct tether via an intermolecular disulfide bond. Disulfide exchange is possible because conotoxin μO§-GVIIJ contains anS-cysteinylated Cys-24 residue that is capable of exchanging with a free cysteine thiol on the channel surface.

A Naturally Occurring Peptide with an Elementary Single Disulfide-Directed β-Hairpin Fold.

Certain peptide folds, owing to a combination of intrinsic stability and resilience to amino acid substitutions, are particularly effective for the display of diverse functional groups. Such "privileged scaffolds" are valuable as starting points for the engineering of new bioactive molecules. We have identified a precursor peptide expressed in the venom gland of the marine snail Conus victoriae, which appears to belong to a hitherto undescribed class of molluscan neuropeptides.

Installation of a Rigid EDTA-Like Motif into a Protein α-Helix for Paramagnetic NMR Spectroscopy with Cobalt(II) Ions.

Coupling two copies of an iminodiacetic acid-cysteine hybrid ligand to a pair of cysteine residues positioned in an i, i+4 arrangement within a protein α-helix leads to generation of an EDTA-like metal ion-binding motif. Rigid binding of a Co(II) ion by this motif produces pseudo-contact shifts suitable for paramagnetic NMR structural studies.

N-Terminally extended analogues of the K⁺ channel toxin from Stichodactyla helianthus as potent and selective blockers of the voltage-gated potassium channel Kv1.3.

The voltage-gated potassium channel Kv1.3 is an important target for the treatment of autoimmune diseases and asthma. Blockade of Kv1.

Elevated baseline plasma phospholipid protein (PLTP) levels are an independent predictor of long-term all-cause mortality in patients with diabetes mellitus and known or suspected coronary artery disease.

Objectives: To investigate the long-term prognostic significance of baseline plasma PLTP levels in a group of well-characterized male patients with diabetes mellitus and known or suspected coronary artery disease referred for coronary angiography.

Background: PLTP is a plasma protein that mediates the net transfer and exchange of phospholipids between lipoproteins. It has been implicated in the pathogenesis of atherosclerosis and elevated plasma levels have been reported in patients with diabetes mellitus.

Development of highly selective Kv1.3-blocking peptides based on the sea anemone peptide ShK.

ShK, from the sea anemone Stichodactyla helianthus, is a 35-residue disulfide-rich peptide that blocks the voltage-gated potassium channel Kv1.3 at ca. 10 pM and the related channel Kv1.