Investigation of dynamic solution interactions between NET-1 and UNC-5B by multi-wavelength analytical ultracentrifugation.

NET-1 is a key chemotropic ligand that signals commissural axon migration and change in direction. NET-1 and its receptor UNC-5B switch axon growth cones from attraction to repulsion. The biophysical properties of the NET-1 + UNC-5B complex have been poorly characterized. Using multi-wavelength-AUC by adding a fluorophore to UNC-5B, we were able to separate the UNC-5B sedimentation from NET-1. Using both multi-wavelength- and single-wavelength AUC, we investigated NET-1 and UNC-5B hydrodynamic parameters and complex formation. The sedimentation velocity experiments show that NET-1 exists in a monomer-dimer equilibrium. A close study of the association shows that NET-1 forms a pH-sensitive dimer that interacts in an anti-parallel orientation. UNC-5B can form equimolar NET-1 + UNC-5B heterocomplexes with both monomeric and dimeric NET-1.

Fluorescence by self-assembly: autofluorescent peptide vesicles and fibers.

A series of oxidized cysteinyl peptides ([P-Cys-X-OMe]2; P = Boc or H; X = Trp or Glu) showed vesicular and fibrillar assemblies. The anatomy of the self-assembled vesicles from the water-soluble cystine peptide [Cys-Trp-OMe]2 (1a) has been investigated by using various fluorescent probes such as ammonium 8-anilinonaphthalene-1-sulfonate, Nile Red and pyrene. The morphological characterization was carried out by fluorescence lifetime imaging microscopy (FLIM) and super resolution-structured illumination microscopy (SR-SIM) utilizing the autofluorescence of the vesicles stemming from the self-assembly. The self-assembled structures are also observed in solution as evident from the quantitative phase images obtained using a dual-mode digital holographic microscope (DHM) system. Present investigations show that the self-assembly is enthalpy- and entropy-driven in the aqueous medium. Based on the CD spectral studies, we proposed that 1a organizes into vesicles through the sequestration of indole units. We observed that the solutions of dipeptides 1a-b exhibit autofluorescence in the blue region upon excitation at a wavelength >350 nm. Detailed spectroscopic studies on the peptides lacking tryptophan 2a-b unequivocally showed that the autofluorescence stems exclusively from peptide aggregation. Our experimental results with appropriate controls revealed that the clustering of carbonyl chromophores is central to autofluorescence. Autofluorescence was also used to probe the vesicle formation without using any external fluorescent probe. To the best of our knowledge, this is the first report on autofluorescent vesicles formed by the spontaneous association of dipeptides. We also found that the vesicles formed by 1a can act as a host for guests like C60. The biocompatibility and biodegradability of these peptides along with the autofluorescent nature and guest binding ability of peptide-based vesicles offer numerous applications in the biomedical area.

Repositioning the existing drugs for neuroinflammation: a fusion of computational approach and biological validation to counter the Parkinson's disease progression.

Parkinson's disease is caused by the deficiency of striatal dopamine and the accumulation of aggregated α-synuclein in the substantia nigra pars compacta (SNpc). Neuroinflammation associated with oxidative stress is a key factor contributing to the death of dopaminergic neurons in SNpc and advancement of Parkinson's disease. Two molecular targets, i.e., nuclear factor kappa-light-chain-enhancer (NF-kB) and α-synuclein play a substantial role in neuroinflammation progression. Therefore, the compounds targeting these neuroinflammatory targets hold a great potential to combat Parkinson's disease. Thereby, in this study, molecular docking and Connectivity Map (CMap) based gene expression profiling was utilized to reposition the approved drugs as neuroprotective agents for Parkinson's disease. With in silico screening, two drugs namely theophylline and propylthiouracil were selected for anti-neuroinflammatory activity evaluation in in vivo models of chronic neuroinflammation. The neuroinflammatory effect of the identified compounds was confirmed by quantifying the expression of three important neuroinflammatory mediators, i.e. IL-6, TNF-alpha, and IL-1 beta on brain tissue using ELISA assay. The ELISA experiment demonstrated that both compounds significantly decreased the expression of neuroinflammatory mediators, highlighting the compounds' potential in neuroinflammation management. Furthermore, the drug and disease interaction network of the two identified drugs and diseases (neuroinflammation and Parkinson's disease) suggested that the two drugs might interact with various targets namely adenosine receptors, Poly [ADP-ribose] polymerase-1, myeloperoxidase (MPO) and thyroid peroxidase through multiple pathways associated with neuroinflammation and Parkinson's disease. Computational studies suggest that a particular drug may be effective in managing Parkinson's disease associated with neuroinflammation. However, further research is needed to confirm this in biological experiments.

Neglected extensive Aspergillus osteomyelitis of the pelvis, femur, and vertebra in an immunocompetent patient: A case report.

De novo Aspergillus infections of the appendicular skeleton are rare. A 72-year-old female presented with pain and deformity in her left lower limb and an inability to bear weight that had persisted for the last six months. A femur biopsy confirmed the diagnosis of extensive Aspergillus osteomyelitis, and the patient was treated with amphotericin B and oral voriconazole. The patient died of COVID-19 after 2.5 months of treatment. A diagnosis of Aspergillus osteomyelitis may be delayed because of its varied clinical presentation. To the best of our knowledge, this is the first known case of de novo neglected and extensive (multisite, multibone) Aspergillus osteomyelitis in an immunocompetent patient. This case highlights the importance of awareness in patients and treating physicians of this rare infection and its early diagnosis to prevent extensive spread.

Association between Long Term Exposure to Air Pollution, Impaired Fasting Glucose, Impaired Glucose Tolerance and Prevalence of Diabetes.

Air pollution exposure have been shown to adversely impact health through a number of biological pathways, and is also associated with glucose metabolism. There are few studies that evaluated the associations between air pollution and fasting blood sugar and HbA1C levels. But no such study occurred in Indian population. Hence to address this knowledge gap, we investigated the associations between air borne fine particulate matter (PM10, PM2.5), nitrogen di-oxide and glucose metabolism in a tertiary care center in north western rajasthan. MATERIAL: We performed cross-sectional analysis in 3457 participants between 30 to 70 years of age group from five different urban and rural areas of Bikaner district. Air pollution concentration of multiple air pollutants (PM10, PM2.5andNitogen dioxide) were estimated by ambient air quality standard method by respiratory dust sampler. Diabetes was defined based on self reported diagnosis, medication prescription, oral glucose tolerance test and HbA1C. We adjusted for potential confounders including socio-economic status, smoking habits, alcohol consumtion, physical activity and Body Mass Index (BMI) by using logistic regression method. OBSERVATION: After adjustment for potential confounders, air pollutants PM10, NO2, except PM2.5 were associated with diabetes prevalence. The prevalence of diabetes was 8.93% and the mean HbA1C was 8.67±1.16, where as the concentration of PM10 was 156.12 mcg/m3, NO2 was 5.43 mcg/m3 and PM2.5 was 25.36 mcg/m3. The prevalence of IFG, IGT and diabetes increases with increased concentration of air pollutants. By applying Pearson's co-relation for air pollutants the 'r' value of PM10was 0.163, p value < 0.001, for PM2.5 'r' value was 0.001 and p value 0.965, for NO2 'r' value was 0.149 and p value was 0.001 respectively. By applying step wise logistic regression analysis, air pollutants PM10 (Odd Ratio 0.002, 95% CI 0.002;0.003) and by adding duration of exposure to air pollutants (Odd ratio 0.003,95%CI 0.001,0.005) by adding PM2.5 air pollutant (odd ratio 0.028,95%CI -0.042,-0.015) and by adding NO2 (odd ratio 0.140,95% CI 0.104,0.175). CONCLUSION: long term air pollution exposure was associated with impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and prevalence of diabetes mellitus (DM). This study can be used as a good evidence that air pollution is an important and manageable risk factor for diabetes hence awareness about air pollution in the society and at government level is much needed.

Homogenous overexpression of the extracellular matrix protein Netrin-1 in a hollow fiber bioreactor.

The production of recombinant proteins for functional and biophysical studies, especially in the field of structural determination, still represents a challenge as high quality and quantities are needed to adequately perform experiments. This is in part solved by optimizing protein constructs and expression conditions to maximize the yields in regular flask expression systems. Still, work flow and effort can be substantial with no guarantee to obtain improvements. This study presents a combination of workflows that can be used to dramatically increase protein production and improve processing results, specifically for the extracellular matrix protein Netrin-1. This proteoglycan is an axon guidance cue which interacts with various receptors to initiate downstream signaling cascades affecting cell differentiation, proliferation, metabolism, and survival. We were able to produce large glycoprotein quantities in mammalian cells, which were engineered for protein overexpression and secretion into the media using the controlled environment provided by a hollow fiber bioreactor. Close monitoring of the internal bioreactor conditions allowed for stable production over an extended period of time. In addition to this, Netrin-1 concentrations were monitored in expression media through biolayer interferometry which allowed us to increase Netrin-1 media concentrations tenfold over our current flask systems while preserving excellent protein quality and in solution behavior. Our particular combination of genetic engineering, cell culture system, protein purification, and biophysical characterization permitted us to establish an efficient and continuous production of high-quality protein suitable for structural biology studies that can be translated to various biological systems. KEY POINTS: • Hollow fiber bioreactor produces substantial yields of homogenous Netrin-1 • Biolayer interferometry allows target protein quantitation in expression media • High production yields in the bioreactor do not impair Netrin-1 proteoglycan quality.

Diagnostic and Prognostic Role of Neutrophil-to-Lymphocyte Ratio in Early and Late Phase of Sepsis.

OBJECTIVE: Early diagnosis of sepsis is necessary to decrease morbidity and mortality. This study aims to evaluate neutrophil-to-lymphocyte ratio (NLR) as diagnostic and prognostic of early and late phase of sepsis. METHODS: It was a prospective, observational study, conducted in Intensive Care and High Dependency Unit (Daycare) of the Department of Pulmonary and Critical Care Medicine (tertiary care center), Rohtak, from January 2017 to December 2017. A total of 56 cases of newly diagnosed cases of sepsis were included in the study and 20 healthy adults were taken as controls. Daily NLR was calculated in cases till the primary outcome. RESULTS: The results suggested that NLR seems to have promising role as diagnostic and prognostic marker (with P = 0.001 and P = 0.045, respectively) in sepsis. CONCLUSION: The study suggests that NLR can be a useful diagnostic and prognostic marker in sepsis.

Room-Temperature Oligomeric Discotic Nematic Liquid Crystals over a Wide Temperature Range: Structure-Property Relationships.

The design and synthesis of three room-temperature discotic nematic (ND ) liquid crystals (LCs) is presented. The LC consists of an azobenzene core attached to which are four pentaalkynylbenzene (PA) units through flexible alkyl spacers. The presence of a short azo linking group provides more disorder in the system, thereby reducing the packing efficiency among the PA units and resulting into the formation of a room-temperature ND phase over a wide temperature range. Dielectric constant and birefringence studies were performed to gain further insights into the physical properties of the mesophase.

Enhanced fluorescence of aqueous BODIPY by interaction with cavitand cucurbit[7]uril.

One cationic BODIPY chromophore was synthesized and its complexation behaviour with the macrocyclic host cucurbit[7]uril (CB[7]) was studied using different spectroscopy techniques such as UV-vis absorption, steady-state and time-resolved fluorescence, 1H NMR as well as DFT based quantum calculations. The dye showed formation of a 1 : 1 dye-CB[7] complex with improvement in the fluorescence intensity. These new results of the formation of moderate association of aqueous BODIPYs with the nontoxic host CB[7] may lead to promising applications of the dye molecule as a sensitive and efficient off-on mode fluorescent probe in chemical and biological studies.

Fusion of Structure and Ligand Based Methods for Identification of Novel CDK2 Inhibitors.

Cyclin dependent kinases play a central role in cell cycle regulation which makes them a promising target with multifarious therapeutic potential. CDK2 regulates various events of the eukaryotic cell division cycle, and the pharmacological evidence indicates that overexpression of CDK2 causes abnormal cell-cycle regulation, which is directly associated with hyperproliferation of cancer cells. Therefore, CDK2 is regarded as a potential target molecule for anticancer medication. Thus, to decline CDK2 activity by potential lead compounds has proved to be an effective treatment for cancer. The availability of a large number of X-ray crystal structures and known inhibitors of CDK2 provides a gateway to perform efficient computational studies on this target. With the aim to identify new chemical entities from commercial libraries, with increased inhibitory potency for CDK2, ligand and structure based computational drug designing approaches were applied. A druglike library of 50,000 compounds from ChemDiv and ChemBridge databases was screened against CDK2, and 110 compounds were identified using the parallel application of these models. On in vitro evaluation of 40 compounds, seven compounds were found to have more than 50% inhibition at 10 µM. MD studies of the hits revealed the stability of these inhibitors and pivotal role of Glu81 and Leu83 for binding with CDK2. The overall study resulted in the identification of four new chemical entities possessing CDK2 inhibitory activity.

Comparative evaluation of esthetic changes in nonpitted fluorosis stains when treated with resin infiltration, in-office bleaching, and combination therapies.

OBJECTIVES: Dental fluorosis leads to esthetic deviation and varies from nonpitted white opacities, dark brown stains to pitting or structural breakdown of enamel surface. Treatment for fluorosis depends on the severity of condition and includes both noninvasive methods and invasive methods. Recently resin infiltration has been proposed as an alternative treatment for nonpitted fluorosis. This study was done to evaluate the esthetic changes in nonpitted fluorosis stains when treated with resin infiltration, in-office bleaching and combination therapies. MATERIALS AND METHODS: The present study is a randomized, single blinded controlled trial with four parallel arms with 1:1 allocation ratio. The intervention arms included bleaching with 35% hydrogen peroxide, resin infiltration, resin infiltration with increased infiltration time and a combination approach of bleaching and infiltration. Immediate esthetic changes were evaluated for two parameters including, 'Change in esthetics' and 'Improvement in opacities/stains' using a VAS scale by two independent observers. Kruskal-Wallis test and Mann-Whitney U-test were done for intergroup comparisons. RESULTS: Best results for both the parameters were observed among patients treated with resin infiltration with increased infiltration time. Mann-Whitney U test revealed significantly better results for resin infiltration groups (alone or combination with bleaching) as compared to bleaching alone (P < .001). CONCLUSIONS: Resin infiltration procedure with tailored etching times and increased infiltration time exhibited best results in terms of change in esthetics and improvement in stains. CLINICAL SIGNIFICANCE: White and brown opacities due to fluorosis have always been a concern for esthetics. In our study, resin infiltration technique with tailored etching times and increased infiltration time exhibited best immediate esthetic improvement for nonpitted fluorotic opacities and stains. These esthetic outcomes reaffirm the applicability of RI technique for nonpitted fluorosis, which was originally advocated only for white spot lesions due to early caries. This will in turn help the dentists to plan the esthetic management of nonpitted fluorosis in a micro-invasive manner.

Effect of ingredients on the quality characteristics of gluten free snacks.

Grain-based fabricated snacks from non-wheat grains (amaranth, finger millet, sorghum and black gram) were used to prepare puffed snacks employing the method of hot air toasting. The functional characteristics and sensory attributes of the snack were determined by varying the moisture content and time of toasting. The quality attributes of the snacks like the instrumental color parameters, peak force and puff thickness of the snack correlated well with the sensory attributes (appearance/color, texture and overall acceptability). A snack made from amaranth showed a bright reddish brown colour at a moisture content of 20-40%; the product had a good puffing and high overall acceptability. The moisture content of all the snacks was around 3% and had a fat content of 1-2%; protein and dietary fiber contents were in the ranges of 22-23 and 10-11%, respectively. The principal component analysis (PCA) accounted for a total of 89.6% variation. The PCA biplot showed that sensory appearance, sensory texture and sensory overall acceptability were closely related to the puff thickness. The microstructure of the snack indicated the presence of air cells to offer a porous structure. On toasting, the flakes increased their thickness creating a porous microstructure such that the toasted snacks were crispy having a brittle texture. Popped sorghum and gelatinized starch added doughs exhibited good puffing when toasted at 20-30% moisture content while popped amaranth samples required higher moisture content (30-40%). The grain based gluten-free snacks with improved sensory and nutritional characteristics can be prepared by using different ingredients.

Bay-Annulated Perylene Tetraesters: A New Class of Discotic Liquid Crystals.

Selenium-annulated perylene tetraesters that stabilize the hexagonal columnar phase have been synthesized and characterized, and their thermal and photophysical behavior has been determined. The mesophase range decreased with an increase in chain length. A comparative account of the structure-property relationships of this series of compounds with respect to parent perylene tetraesters, N- and S-annulated perylene tetraesters, in terms of their thermal, photophysical and electrochemical behavior is provided. The bay-annulation of perylene tetraesters is a good option to modify the thermal and photophysical properties of perylene derivatives and it can provide a new avenue for the synthesis of several technologically important self-assembling perylene derivatives.

Triphenylene-Based Room-Temperature Discotic Liquid Crystals: A New Class of Blue-Light-Emitting Materials with Long-Range Columnar Self-Assembly.

A straightforward synthesis of multialkynylbenzene-bridged triphenylene-based dyad systems (via flexible alkyl spacers) that self-organize into room-temperature columnar structures over a long range is reported. The compounds with spacer lengths (n) of 8 and 10 exhibit a columnar rectangular mesophase whereas a compound with n = 6 shows a columnar rectangular plastic phase. Interestingly, the later compound (n = 6) shows the formation of well-nucleated spherulites of about several hundred micrometers that suggest the existence of a long-range uniform self-assembly of columns. All of these compounds show blue luminescence in solution and in the thin-film state under long-wavelength (365 nm) UV light. These compounds fulfill the described demands such as long-range columnar self-assembly at room temperature, a good yield with high purity, and blue-light emitters under the neat condition for possible potential applications in semiconductor devices. They also match the criteria of facile processing from the isotropic state because of their low isotropization temperature. This new class of materials is promising, considering the emissive nature and stabilization of the columnar mesophase at ambient temperature.

Liquid-Crystalline Star-Shaped Supergelator Exhibiting Aggregation-Induced Blue Light Emission.

A family of closely related star-shaped stilbene-based molecules containing an amide linkage are synthesized, and their self-assembly in liquid-crystalline and gel states was investigated. The number and position of the peripheral alkyl tails were systematically varied to understand the structure-property relation. Interestingly, one of the molecules with seven peripheral chains was bimesomorphic, exhibiting columnar hexagonal and columnar rectangular phases, whereas the rest of them stabilized the room-temperature columnar hexagonal phase. The self-assembly of these molecules in liquid-crystalline and organogel states is extremely sensitive to the position and number of alkoxy tails in the periphery. Two of the compounds with six and seven peripheral tails exhibited supergelation behavior in long-chain hydrocarbon solvents. One of these compounds with seven alkyl chains was investigated further, and it has shown higher stability and moldability in the gel state. The xerogel of the same compound was characterized with the help of extensive microscopic and X-ray diffraction studies. The nanofibers in the xerogel are found to consist of molecules arranged in a lamellar fashion. Furthermore, this compound shows very weak emission in solution but an aggregation-induced emission property in the gel state. Considering the dearth of solid-state blue-light-emitting organic materials, this molecular design is promising where the self-assembly and emission in the aggregated state can be preserved. The nonsymmetric design lowers the phase-transition temperatures.The presence of an amide bond helps to stabilize columnar packing over a long range because of its polarity and intermolecular hydrogen bonding in addition to promoting organogelation.

Benzothiazole Derivative as a Novel Mycobacterium tuberculosis Shikimate Kinase Inhibitor: Identification and Elucidation of Its Allosteric Mode of Inhibition.

Mycobacterium tuberculosis shikimate kinase (Mtb-SK) is a key enzyme involved in the biosynthesis of aromatic amino acids through the shikimate pathway. Since it is proven to be essential for the survival of the microbe and is absent from mammals, it is a promising target for anti-TB drug discovery. In this study, a combined approach of in silico similarity search and pharmacophore building using already reported inhibitors was used to screen a procured library of 20,000 compounds of the commercially available ChemBridge database. From the in silico screening, 15 hits were identified, and these hits were evaluated in vitro for Mtb-SK enzyme inhibition. Two compounds presented significant enzyme inhibition with IC50 values of 10.69 ± 0.9 and 46.22 ± 1.2 µM. The best hit was then evaluated for the in vitro mode of inhibition where it came out to be an uncompetitive and noncompetitive inhibitor with respect to shikimate (SKM) and ATP, respectively, suggesting its binding at an allosteric site. Potential binding sites of Mtb-SK were identified which confirmed the presence of an allosteric binding pocket apart from the ATP and SKM binding sites. The docking simulations were performed at this pocket in order to find the mode of binding of the best hit in the presence of substrates and the products of the enzymatic reaction. Molecular dynamics (MD) simulations elucidated the probability of inhibitor binding at the allosteric site in the presence of ADP and shikimate-3-phosphate (S-3-P), that is, after the formation of products of the reaction. The inhibitor binding may prevent the release of the product from Mtb-SK, thereby inhibiting its activity. The binding stability and the key residue interactions of the inhibitor to this product complex were also revealed by the MD simulations. Residues ARG43, ILE45, and PHE57 were identified as crucial that were involved in interactions with the best hit. This is the first report of an allosteric binding site of Mtb-SK, which could largely address the selectivity issue associated with kinase inhibitors.

Perylo[1,12-b,c,d] Thiophene Tetraesters: A New Class of Luminescent Columnar Liquid Crystals.

Perylo[1,12-b,c,d] thiophene tetraesters exhibiting wide-range hexagonal columnar phase have been synthesized. These compounds also exhibit good homeotropic alignment in the liquid-crystalline phase which is very important for the device fabrication. These compounds showed sky-blue luminescence in solution under the long-wavelength UV light. With high solubility and high quantum yield these compounds can serve as standards to measure quantum yields of unknown samples. This new class of materials is promising, considering the emissive nature and stabilization of hexagonal columnar mesophase over a wide thermal range and ease of synthesis.

High laser efficiency and photostability of pyrromethene dyes mediated by nonpolar solvent.

Many pyrromethene (PM) dyes have been shown to outperform established rhodamine dyes in terms of laser efficiency in the green-yellow spectral region, but their rapid photochemical degradation in commonly used ethanol or methanol solvents continues to limit its use in high average power liquid dye lasers. A comparative study on narrowband laser efficiency and photostability of commercially available PM567 and PM597 dyes, using nonpolar n-heptane and 1,4-dioxane and polar ethanol solvents, was carried out by a constructed pulsed dye laser, pumped by the second harmonic (532 nm) radiation of a Q-switched Nd:YAG laser. Interestingly, both nonpolar solvents showed a significantly higher laser photostability (∼100 times) as well as peak efficiency (∼5%) of these PM dyes in comparison to ethanol. The different photostability of the PM dyes was rationalized by determining their triplet-state spectra and capability to generate reactive singlet oxygen (O21) by energy transfer to dissolved oxygen in these solvents using pulse radiolysis. Heptane is identified as a promising solvent for these PM dyes for use in high average power dye lasers, pumped by copper vapor lasers or diode-pumped solid-state green lasers.

Trisomy chromosome 6 as a sole cytogenetic abnormality in acute myeloid leukemia.

Identification of cytogenetic abnormalities plays an important role in the diagnosis and prognosis of leukemias. Isolated trisomy 6 is a rare abnormality, the prognostic significance of which is not well established. We report one case of acute myeloid leukemia (AML-M5 variant) with trisomy 6 as the sole cytogenetic abnormality. Previously, trisomy 6 has been reported in aplastic anemia, myelodysplastic syndrome, and AML, usually associated with hypocellular marrow. However, our patient had a very short history and hypercellular marrow infiltrated with blasts. We report this case due to the rarity of the condition. More studies are required to ascertain the role of trisomy 6 in the development of leukemia as well as in prognosis.

Low grade endometrial stromal sarcoma: a case report.

Endometrial stromal sarcoma (ESS) is a rare malignant tumor of the endometrium, occurring in the age group of 40-50 years. We report a case of low-grade ESS in a 39-year-old woman, presenting as rapid enlargement of a uterine fibroid polyp associated with irregular and excessive vaginal bleeding. Polypectomy followed by pan hysterectomy was performed. Histopathological examination and immunohistochemistry confirmed LGESS. As the tumor is rarely encountered, management protocols are still questionable. In our case, we tried a different post-surgical protocol and the patient is being closely followed up. Although rare, ESS should be considered in the differential diagnosis of all women who present with a rapid enlargement of a uterine leiomyoma.