New insights into the therapeutic approaches for the treatment of tauopathies.

Tauopathies are a group of neurological disorders, including Alzheimer's disease and frontotemporal dementia, which involve progressive neurodegeneration, cognitive deficits, and aberrant tau protein accumulation. The development of tauopathies cannot currently be stopped or slowed down by treatment measures. Given the significant contribution of tau burden in primary tauopathies and the strong association between pathogenic tau accumulation and cognitive deficits, there has been a lot of interest in creating therapies that can alleviate tau pathology and render neuroprotective effects. Recently, small molecules, immunotherapies, and gene therapy have been used to reduce the pathological tau burden and prevent neurodegeneration in animal models of tauopathies. However, the major pitfall of the current therapeutic approach is the difficulty of drugs and gene-targeting modalities to cross the blood-brain barrier and their unintended side effects. In this review, the current therapeutic strategies used for tauopathies including the use of oligonucleotide-based gene therapy approaches that have shown a promising result for the treatment of tauopathies and Alzheimer's disease in preclinical animal models, have been discussed.

Treatment recalcitrant cases of tinea corporis/cruris caused by T. mentagrophytes - interdigitale complex with mutations in ERG11 ERG 3, ERG4, MDR1 MFS genes & SQLE and their potential implications.

BACKGROUND: Recalcitrant dermatophyte infections are being reported from various parts of the world due to varied causes including strain variation, steroid misuse, SQLE mutations, and variable quality of itraconazole pellet formulations. The oral drug preferred in endemic areas is itraconazole, to which MIC levels remain low, and clinical failures to itraconazole reported defy a sound scientific explanation. OBJECTIVES: The objective of the study was to conduct a proteomic and genomic analysis on isolates from therapeutically recalcitrant case with isolation of gene mutations and enzymatic abnormalities to explain azole failures. METHODS: Trichophyton mentagrophyte interdigitale complex strains were isolated from seven clinically non-responding tinea corporis/cruris patients, who had failed a sequential course of 6 weeks of terbinafine 250 mg QD and itraconazole 100 mg BID. After AFST 1 strain, KA01 with high MIC to most drugs was characterized using whole genome sequencing, comparative proteomic profiling, and total sterol quantification. RESULTS: Sterol quantification showed that the standard strain of Trichophyton mentagrophytes (MTCC-7687) had half the ergosterol content than the resistant KA01 strain. Genomic analysis revealed mutations in SQLE, ERG4, ERG11, MDR1, MFS genes, and a novel ERG3 mutation. Proteomic analysis established the aberrant expression of acetyl Co-A transferase in the resistant strain and upregulation of thioredoxin reductase and peroxiredoxin. CONCLUSION: Our findings demonstrate possible reasons for multidrug resistance in the prevalent strain with mutations in genes that predict terbinafine (SQLE) and azole actions (ERG4, ERG11, ERG3) apart from efflux pumps (MDR1, MFS) that can explain multidrug clinical failures.

Chiral Control of Gas-Phase Molecules using Microwave Pulses.

Microwave three-wave mixing has emerged as a novel approach for studying chiral molecules in the gas phase. This technique employs resonant microwave pulses and is a non-linear and coherent approach. It serves as a robust method to differentiate between the enantiomers of chiral molecules and to determine the enantiomeric excess, even in complex chiral mixtures. Besides such analytical applications, the use of tailored microwave pulses allows us to control and manipulate chirality at the molecular level. Here, an overview of some recent developments in the area of microwave three-wave mixing and its extension to enantiomer-selective population transfer is provided. The latter is an important step towards enantiomer separation-in energy and finally in space. In the last section, we present new experimental results on how to improve enantiomer-selective population transfer to achieve an enantiomeric excess of about 40 % in the rotational level of interest using microwave pulses alone.

Inducing transient enantiomeric excess in a molecular quantum racemic mixture with microwave fields.

Chiral molecules with low enantiomer interconversion barriers racemize even at cryogenic temperatures due to quantum tunneling, forming a racemic mixture that is impossible to separate using conventional chemical methods. Here we both experimentally and theoretically demonstrate a method to create and probe a state-specific enantiomeric enrichment for such molecular systems. The coherent, non-linear, and resonant approach is based on a microwave six-wave mixing scheme and consists of five phase-controlled microwave pulses. The first three pulses induce a chiral wavepacket in a chosen rotational state, while the consecutive two pulses induce a polarization for a particular rotational transition (listen transition) with a magnitude proportional to the enantiomeric excess created. The experiments are performed with the transiently chiral molecule benzyl alcohol, where a chiral molecular response was successfully obtained. This signal demonstrates that enantiomeric excess can be induced in a quantum racemic mixture of a transiently chiral molecule using the developed microwave six-wave mixing scheme, which is an important step towards controlling non-rigid chiral molecular systems.

The many forms of alpha-methoxy phenylacetic acid in the gas phase: flexibility, internal dynamics, and their intramolecular interactions.

We present a rotational spectroscopy study of alpha-methoxy phenylacetic acid in the gas phase. This acid is a derivative of mandelic acid and is used in various organic reactions. The conformational landscape of alpha-methoxy phenylacetic acid was explored to gain insight into its intramolecular dynamics. A rich rotational spectrum was obtained using chirped-pulse Fourier transform microwave spectroscopy in the 2-8 GHz range. Five conformers out of six calculated low-energy forms were identified in the spectrum, and the assignment of the 13C singly substituted isotopologues for the lowest-energy conformer led to its accurate structure determination. Splitting patterns were analyzed and attributed to the internal rotation of a methyl top. The analysis of the non-covalent interactions within the molecule highlights the subtle balance in the stabilization of the different conformers. We thus provide high-level structural and intramolecular dynamics information that is also used to benchmark the performance of quantum-chemical calculations.

A potent antibiotic-loaded bone-cement implant against staphylococcal bone infections.

New antibiotics should ideally exhibit activity against drug-resistant bacteria, delay the development of bacterial resistance to them and be suitable for local delivery at desired sites of infection. Here, we report the rational design, via molecular-docking simulations, of a library of 17 candidate antibiotics against bone infection by wild-type and mutated bacterial targets. We screened this library for activity against multidrug-resistant clinical isolates and identified an antibiotic that exhibits potent activity against resistant strains and the formation of biofilms, decreases the chances of bacterial resistance and is compatible with local delivery via a bone-cement matrix. The antibiotic-loaded bone cement exhibited greater efficacy than currently used antibiotic-loaded bone cements against staphylococcal bone infections in rats. Potent and locally delivered antibiotic-eluting polymers may help address antimicrobial resistance.

Efficacy of 2% Rebamipide Suspension for Vernal Keratoconjunctivitis: A Clinical Comparison with Topical Immune Modulators Cyclosporine and Tacrolimus.

PURPOSE: To compare the efficacy of 2% rebamipide suspension with topical cyclosporine and tacrolimus for managing vernal keratoconjunctivitis (VKC). METHODS: In this prospective, interventional study, 38 patients with moderate to severe VKC were allocated to receive either 2% rebamipide in one eye and 0.03% tacrolimus ointment in the contralateral eye (n = 19) or 2% rebamipide in one eye and 0.05% cyclosporine in the contralateral eye (n = 19) for 12 weeks. Ten ocular signs and 7 symptoms were graded on a scale of 0-3 each for each eye at every visit. RESULTS: Total sign and symptom scores reduced significantly in all 4 subgroups (all p's <0.05) at 12 weeks. Reduction of mean sign scores between rebamipide and tacrolimus (- 4.67 ± 4.63 and - 2.80 ± 3.18 respectively) and between rebamipide and cyclosporine (-6.00 ± 3.74 and -5.42 ± 3.68 respectively) was comparable. Reduction in symptom scores was also comparable between subgroups. CONCLUSION: Our findings suggest that efficacy of topical rebamipide is comparable to topical cyclosporine and tacrolimus for managing moderate to severe VKC and it merits further evaluation as a novel steroid sparing alternative for this disorder.

Long-term efficacy and safety of imiquimod 5% and fluorouracil 1% creams in medical monotherapy of complex eyelid basal cell carcinomas.

PURPOSE: To study the long-term efficacy and safety of local application of imiquimod 5% and fluorouracil 1% creams in complex eyelid basal cell carcinomas (BCCs). METHODS: A retrospective, non-comparative study in biopsy-proven, complex (involving canthi or >50% of eyelid length) eyelid BCC patients who were medically unfit for surgical procedures. All patients were medically treated with either of the creams using fixed-dose regimens for a minimum of 3 months. All received oral vitamin C 500 mg QID for 3 months as an adjunct for collagen healing. A minimum of "post-treatment" follow-up of 12 months was observed. RESULTS: Of total 30 patients, imiquimod 5% and fluorouracil 1% were used in 16 and 14 patients, respectively. The mean age of our patients was 70.5 years. The co-morbidities included - severe coronary artery disease using blood-thinners (n = 19), poorly controlled diabetes (n = 12), poorly controlled hypertension (n = 6), on nebulization (n = 3), and tuberculosis with pulmonary fibrosis (n = 2). Complete clinical tumor resolution was noted in 10 and 8 patients over 12 and 16.5 weeks, respectively, in imiquimod and fluorouracil groups. Periocular skin erythema, chemical conjunctivitis, and skin depigmentation were seen in all the patients of imiquimod group. On the other hand, the local side-effect profile in fluorouracil patients was limited. CONCLUSION: The medical treatment of complex eyelid BCC is a useful alternative to surgery in the elderly with significant co-morbidities. It provides a promising long-term relief with a tolerable side-effect profile. A prospective, randomized, double-blinded trial would provide stronger evidence for the efficacy of these drugs.

Antibiofilm activity of Fmoc-phenylalanine against Gram-positive and Gram-negative bacterial biofilms.

Biofilm associated infections are the major contributor of mortality, morbidity and financial burden in patients with a bacterial infection. About 65% of all bacterial infections are associated with the information of bacterial biofilms. Bacterial biofilms not only reduce the efficacy of antibacterial treatment but also increases the threat of developing antibacterial resistance. Recently, our group has discovered the antibacterial activity of Fmoc-phenylalanine (Fmoc-F) and other Fmoc-amino acids (Fmoc-AA). Fmoc-F and other Fmoc-AA showed antibacterial activity due to their surfactant properties. Surfactants are known to eradicate biofilm and enhance antimicrobial activity in biofilm. Thus, in the present study, we evaluated the anti-biofilm activity of Fmoc-F against clinically relevant bacteria. We found that Fmoc-F not only inhibits the biofilm formation in Staphylococcus aureus and Pseudomonas aeruginosa, but also eradicates the already formed biofilms over the surface. Further, Fmoc-F coated glass surface resists S. aureus and P. aeruginosa biofilm formation and attachment, when biofilm is grown over the surface. The mechanistic investigation suggests that Fmoc-F reduces the extracellular matrix (ECM) components such as proteins, carbohydrates and eDNA in the biofilm and affect its stability via direct interactions with ECM components and/ or indirectly through reducing bacterial cell population. Finally, we showed that Fmoc-F treatment in combination with vancomycin and ampicillin synergistically inhibit biofilm formation. Overall, the study demonstrates the potential application of Fmoc-F and other Fmoc-AA molecules individually as well as in combination as anti-biofilm coating material for treating biofilm associated infections.

Repurposing of thalidomide and its derivatives for the treatment of SARS-coV-2 infections: Hints on molecular action.

AIMS: The SARS-coV-2 pandemic continues to cause an unprecedented global destabilization requiring urgent attention towards drug and vaccine development. Thalidomide, a drug with known anti-inflammatory and immunomodulatory effects has been indicated to be effective in treating a SARS-coV-2 pneumonia patient. Here, we study the possible mechanisms through which thalidomide might affect coronavirus disease-19 (COVID-19). METHODS: The present study explores the possibility of repurposing thalidomide for the treatment of SARS-coV-2 pneumonia by reanalysing transcriptomes of SARS-coV-2 infected tissues with thalidomide and lenalidomide induced transcriptomic changes in transformed lung and haematopoietic models as procured from databases, and further comparing them with the transcriptome of primary endothelial cells. RESULTS: Thalidomide and lenalidomide exhibited pleiotropic effects affecting a range of biological processes including inflammation, immune response, angiogenesis, MAPK signalling, NOD-like receptor signalling, Toll-like receptor signalling, leucocyte differentiation and innate immunity, the processes that are aberrantly regulated in severe COVID-19 patients. CONCLUSION: The present study indicates thalidomide analogues as a better fit for treating severe cases of novel viral infections, healing the damaged network by compensating the impairment caused by the COVID-19.

Mechanistic Insight Into the Antifungal Effects of a Fatty Acid Derivative Against Drug-Resistant Fungal Infections.

The prevalence of drug-resistant pathogenic fungi is a major global health challenge. There is an urgent need for novel drugs that can exert a potent antifungal activity and overcome resistance. Newly discovered anti-fungal properties of existing compounds can potentially offer a rapid solution to address this persistent threat. We rationalized that structures which disrupt the fungal cell membrane could address the above unmet need. As fatty acids underpin the formation and stability of cell membranes, we used computational simulations to evaluate the interactions between selected short chain fatty acids and a model cell membrane. Here, we report that caprylic acid could penetrate and perturb the membrane in silico. Based on the in silico findings, we identified a derivative of this fatty acid that disrupts fungal membranes as detected using steady-state fluorescence anisotropy. We show that this fatty acid derivative is potent against a variety of fungal pathogens like Candida and Trichophyton. We further demonstrated the ability of this fatty acid derivative to potentiate some azoles in vitro and enhance the efficacy of antifungal formulations in vivo. Our data suggests the emergence of a novel therapy for effective disease management and overcoming anti-fungal drug resistance.

Newly Developed Anti-Dandruff Regimen, VB-3222, Delivers Enhanced Sensorial and Effective Therapeutic Benefits Against Moderate Adherent Dandruff.

BACKGROUND: Uninhibited proliferation of Malassezia spp., enhanced sebaceous gland activity and individual sensitivity are three prime etiological factors behind dandruff. For many dandruff sufferers, existing anti-dandruff products start yielding unsatisfactory results after a few cycles of use. This observation made us explore the physical and biological environment of the host and exploit the specific type of lipid dependence of Malassezia spp. for their survival. A shampoo formulation (product code VB-3222) was developed to address the shortcomings of existing therapy. PURPOSE: Evaluating efficacy of VB-3222 in comparison to marketed products through  in vitro assays and subsequently demonstrating its advantages in a clinical study. METHODS: VB-3222 was developed with a derivative of medium chain fatty acid (MCFA) and zinc pyrithione and compared against marketed comparators by in vitro time kill assay. Subsequently, VB-3222 shampoo was tested in a 21-day clinical trial on 25 moderate dandruff subjects to evaluate local safety and efficacy. RESULTS: VB-3222 in all in vitro cases demonstrated significantly better fungicidal activity than its marketed comparators. In the clinical trial, VB-3222 was well tolerated in all subjects and imparted consistent reduction of the ASFS (adherent scalp flaking score) and the pruritus score. At days 7 and 21, 55% and 90% reduction in the ASFS in comparison to treatment initiation and 50% and 95.5% reduction in the pruritus score were observed. CONCLUSION: The increased efficacy of VB-3222 over comparator products in vitro, and the dramatic reduction (>90%) in ASFS and pruritis in subjects within 21 days of use with excellent tolerability and sensorial profile, positions VB-3222 as the new generation treatment for adherent dandruff. CLINICAL TRIAL REGISTRATION NO: CTRI/2018/05/013567.

Probing the adsorption of nonionic micelles on different-sized nanoparticles by scattering techniques.

The interaction of nanoparticles with surfactants is extensively used in a wide range of applications from enhancing colloidal stability to phase separation processes as well as in the synthesis of noble functional materials. The interaction is highly specific depending on the charged nature of the surfactant. In the case of nonionic surfactants, the micelles adsorb on the surface of nanoparticles. The adsorption of nonionic surfactant C12E10 as a function of surfactant concentration for two different sizes of anionic silica nanoparticles (16 and 27 nm) has been examined using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). SANS measurements have been carried out under different contrast-matched conditions, where nanoparticles, as well as surfactant micelles, have been contrast-matched to the solvent. The adsorption of micelles is determined from the contrast-matched condition of silica nanoparticles with the solvent. SANS data under surfactant contrast-matched condition suggest that there is no modification in the structure and/or interaction of the silica nanoparticles in presence of nonionic micelles. The adsorption of micelles on nanoparticles is found to follow an exponential behavior with respect to the surfactant concentration. These results are consistent with the variation of hydrodynamic size of nanoparticle-surfactant system in DLS. The study on different-sized nanoparticles shows that the lower curvature enhances the packing fraction whereas the loss of surface-to-volume ratio suppresses the fraction of adsorbed micelles with the increase in the nanoparticle size. The adsorption coefficient has higher value for the larger size of the nanoparticles. In the mixed system of two sizes of nanoparticles, no preferential selectivity of micelle adsorption is observed.

A Rationally Designed Multifunctional Antibiotic for the Treatment of Drug-Resistant Acne.

Acne is a multifactorial skin disease, underpinned by colonization of Propionibacterium acnes and inflammation. The emergence of resistant P. acnes strains has affected the current acne treatment algorithm. This setback served as an impetus for rationally designing a library of next-generation antibiotics that exhibit a bactericidal effect on resistant P. acnes and exert an immunomodulatory function to reduce inflammation. In silico screening showed that one of the molecules, VCD-004, exhibits improved mode of binding to bacterial DNA gyrase. VCD-004 shows high potency against clinical isolates of resistant P. acnes and excellent efficacy in vivo. Furthermore, VCD-004 exhibits a superior mutant prevention index, suggesting that it impedes the development of resistance better than clindamycin. Additionally, it shows optimal skin penetration and has a potent anti-inflammatory effect via reduction of proinflammatory cytokines (IL-6) independent of its antibacterial action. VCD-004 affects P. acnes-induced nuclear accumulation of NF-κB in THP-1 cells. The in vitro viability of human keratinocytes in the presence of VCD-004 indicates a desirable therapeutic window for topical use. Such rationally designed bactericidal and immunomodulatory dual pharmacophore-based lipophilic molecule(s) can emerge as the next-generation topical therapy for acne with underlying resistant P. acnes etiology.

An improved method suitable for isolation of high-quality metagenomic DNA from diverse soils.

Standardization of metagenomic DNA extraction protocol is a pre-requisite for a successful metagenomic study aiming to screen and exploit the variety of microorganisms inhabiting a particular soil environment. Six methods reported earlier were used for isolation of metagenomic DNA in the present study. These methods suffered with regard to either poor yield or quality of DNA. Therefore, we developed an improved method for isolation of high-molecular weight and good quality metagenomic DNA from different soil samples. Our protocol combines the enzymatic (lysozyme and proteinase K) and chemical (CTAB and CaCl2) strategies to ensure efficient cell lysis and use of PEG and isopropanol for precipitation of humic impurities-free DNA. Our improved method gave high yield of good quality metagenomic DNA from diverse soils collected from garden, domestic waste dumping site, cellulose waste dumping site, sewage site, and tannery waste site. The good quality of the metagenomic DNA was evident by spectrophotometry data, PCR amplification of 16S rRNA gene and restriction digestion.

Attitude, complications, ability of fasting and glycemic control in fasting Ramadan by children and adolescents with type 1 diabetes mellitus.

OBJECTIVES: Sick individuals and children are exempted from fasting Ramadan. Fasting by type 1 diabetes patients might predispose to acute complications. There are no guidelines on fasting safety or its impact on diabetes control in children and adolescents. We aim to assess patients' attitude towards fasting, frequency of complications and impact on glycemic control in children with type 1 diabetes. RESEARCH DESIGN & METHODS: 65 children with type 1 diabetes were enrolled. The study involved 2 hospital visits. Questionnaires were filled in each visit and HbA1c was recorded. Log books indicating symptomatic hypoglycemia and hyperglycemia leading to breaking fast were obtained. RESULTS: Majority of subjects were willing to fast and 75% were encouraged by parents to do. 57% and 26% fasted more than half and all through the month respectively. 52% had, at least, one episode of hypoglycemia and 29% had hyperglycemia with one episode of ketoacidosis. All patients broke fast in response to symptomatic hypoglycemia/hyperglycemia. There was no significant difference between the frequency of complications in the pump or the Multiple Daily Injection (MDI) groups. Mean HbA1c increased from 70mmol/mol to 73mmol/mol. The difference was not statistically significant. CONCLUSION: Children and adolescents with type 1 diabetes are keen to fast Ramadan and they are able to fast a significant number of days. Hypoglycemia and hyperglycemia are not uncommon with no difference between Pump or in MDI users. Breaking fast on occurrence of complications makes fasting safe. Glycemic control might deteriorate during the month and the following Eid.