An Indian effort towards affordable drugs: "generic to designer drugs"

This review discusses the progress of India from being one of the largest producers of generics to its coming of age and initiating novel drug development programs such as the Open Source Drug Discovery for tuberculosis. A few groups have also begun to emerge which focus their research on rational or structure based drug design. We discuss here some of the ongoing efforts in drug discovery in India primarily in national research institutions and academia

Three-dimensional structure of Mycobacterium tuberculosis chaperonin-10 reveals a partially stable conformation of its mobile loop

The 60 kDa and 10 kDa chaperonins form a unique multimeric complex that mediates several intracellular protein-folding reactions. The 10 kDa chaperonins interact with the 60 kDa chaperonins through a 17-residue long mobile loop which is believed to be highly flexible in the uncomplexed chaperonin-10 but adopts a well ordered conformation upon complex formation with chaperonin-60. We have now solved the three-dimensional structure of Mycobacterium tuberculosis chaperonin-10 and report here a partially stable conformation for its mobile loop. Evolutionary arguments and supporting experimental observations suggest additional conformational rearrangements for chaperonin-10s when associating with chaperonin-60

A Dual-Plasmid-Based CRISPR/Cas9-Mediated Strategy Enables Targeted Editing of pH Regulatory Gene pacC in a Clinical Isolate of Trichophyton rubrum

Trichophyton rubrum is the most prevalent causative agent responsible for 80–90% of all known superficial fungal infections in humans, worldwide. Limited available methods for genetic manipulations have been one of the major bottlenecks in understanding relevant molecular mechanisms of disease pathogenesis in T. rubrum. Here, a dual-plasmid-based CRISPR/Cas9 strategy to edit pH regulatory transcription factor, pacC, of a clinical isolate of T. rubrum by non-homologous end joining (NHEJ) repair is presented. A cas9–eGFP fusion that aids pre-screening of primary transformants through detection of GFP fluorescence is expressed from one plasmid while target-specific sgRNA from the other brings about mutagenesis of pacC with an overall efficiency of 33.8–37.3%. The mutants had reduced transcript levels of pacC at both acidic and alkaline pH with several morphological abnormalities. We believe this dual-plasmid-based CRISPR/Cas9 strategy will aid functional genomics studies, especially in non-lab-adapted clinical strains of T. rubrum

Physical Properties of Intact Proteins May Predict Allergenicity or Lack Thereof

Background: Predicting the allergenicity of proteins is challenging. We considered the possibility that the properties of the intact protein that may alter the likelihood of being taken up by antigen presenting cells, may be useful adjuncts in predicting allergens and non-allergens in silico. It has been shown that negatively charged acidic proteins are preferentially processed by dendritic cells. Methodology: Datasets (aeroallergen, food-allergen and non-allergen) for in-silico study were obtained from public databases. Isoelectric point (pI), net charge, and electrostatic potential (EP) were calculated from the protein sequence (for pI and net charge) or predicted structure (for EP). Result: Allergens and non allergens differed significantly in pI, net charge, and EP (p,0.0001). Cluster analysis based on these parameters resulted in well defined clusters. Non-allergens were characterized by neutral to basic pI (mean6SE, 7.660.16) and positive charge. In contrast allergens were acidic (5.760.15) and negatively charged. Surface electrostatic potentials calculated from predicted structures were mostly negative for allergens and mostly positive for non-allergens. The classification accuracy for non-allergens was superior to that for allergens. Thus neutral to basic pI, positive charge, and positive electrostatic potentials characterize non-allergens, and seem rare in allergens (p,0.0001). It may be possible t

Keratoglobus: An experience at a tertiary eye care center in India

Context: This study was carried out as a part of an internal audit and is the largest series of patients having keratoglobus, published in the literature. Poor visual acuity of the patients indicates the blinding nature of the disease. Aims: We report our experience with patients having keratoglobus at a tertiary eye care center in India. Settings and Design : Retrospective study. Materials and Methods: We analyzed adults and pediatric patients (20/40 in 6/42 (14.3%) pediatric eyes and 15/53 (28.30%) adults. Visual acuity ranging from counting of fingers to no light perception was noted in 20/53 (37.74%) adults and 21/42 (50%) pediatric patients; 13/20 (65%) with blue sclera and 8/22 eyes (36.37%) without blue sclera. Vernal keratoconjunctivitis was present in one pediatric patient. Choroidal osteoma, retinitis pigmentosa, and retinal detachment were present in adults. Surgeries performed were corneal tear repair (5 eyes), tissue adhesive application (2 eyes), descematopexy (4 eyes) and penetrating keratoplasty (PK - 8 eyes: Three had post-PK glaucoma, graft failure-one eye, 4 patients wore scleral lens - prosthetic replacement of the ocular surface ecosystem). Conclusions: About 50% of pediatric eyes (65% having blue sclera) had no functional vision. Trivial trauma was responsible for corneal rupture indicating need for protective glasses. About 50% patients had post-PK glaucoma though grafts were clear

Exploring the Potential of <em>Calotropis procera</em> in Pharmacological Approaches

Medicinal plants have been a source of treatments for many ailments for thousands of years. The WHO estimates that 80% of worldwide population use traditional medicines to treat common health issues. Plant derived bioactive substances constitute 50% of Western medications. The increase in incidents of emerging medical challenges, including post-COVID syndrome, rising multidrug-resistant (MDR), and many more, has raised annual fatalities. To address these issues, novel medications and strategic approaches are urgently required. Designing novel drugs relies on exploring medicinal plants, which have great scope in combating diseases. Calotropis procera is a medicinal plant belongs to Apocynaceae family and subfamily Asclepiadoideae that have been exploring for developing novel drugs. C. procera consists of numerous phytochemicals including flavonoids, terpenoids, cardenolides, steroids and oxypregnanes. Therefore, its phytoconstituents have been used to treat a variety of conditions including cancer, asthma, epilepsy and snake bite. C. procera is reported to have anti-inflammatory, anti-tumor, anthelmintic, antibacterial, antinociceptive and antimalarial properties. Roots, leaves and flower of C. procera have been used in wide range of ethnomedicinal and pharmacological actions including leukoderma, malaria and eczema. Recent ongoing techniques including computational tools using the phytoconstituents of C. procera against various diseases will open up avenues for developing novel drugs

Phototherapeutic keratectomy for recurrent granular dystrophy in postpenetrating keratoplasty eyes

Purpose: The purpose is to assess the clinical and visual outcome after phototherapeutic keratectomy (PTK) procedure in eyes with prior penetrating keratoplasty (PKP) for granular corneal dystrophy (GCD) and the time of performance of repeat PTK for recurrence. Methods: PTK was performed for visually significant recurrence: A reduction in best-corrected visual acuity (BCVA) by >2 lines over BCVA before recurrence was considered as visually significant recurrence. Three eyes had amniotic membrane patch performed with PTK. The main outcome measures were a recurrence of GCD, clinical course, and visual outcome. Intervals between repeat PTK procedures were noted. Results: Six patients (n = 10 eyes; males: 4, mean age 39 ± 13.97 years) underwent PTK. The mean pachymetry before first PTK was 527.1 ± 34 microns. The mean duration between PKP and first PTK was 85.1 months (range: 37–108 months). Two and three PTK procedures were done for seven and five eyes, respectively. Mean duration between first and second and second and third PTK was 62.12 ± 34.41 and 42.8 ± 13.54 months respectively. The average cut depth was 43.66 ± 19.57, 75 ± 43.30 and 39 ± 19.79 microns after the first, second and third PTK procedures, respectively. All eyes had a corneal haze. Pre first PTK mean BCVA was 20/200 and improved significantly after the first two PTK procedures to 20/40 and after the third PTK procedure to 20/32 (P < 0.001). Five eyes had hyperopia. One acute graft rejection was managed successfully at 5 months with medical therapy. Conclusion: Multiple PTK procedures can be performed safely with improved visual acuity in grafts without compromising graft survival

Integration Host Factor of <i>Mycobacterium tuberculosis</i>, mIHF, Compacts DNA by a Bending Mechanism

<div><p>The bacterial chromosomal DNA is folded into a compact structure called as ‘nucleoid’ so that the bacterial genome can be accommodated inside the cell. The shape and size of the nucleoid are determined by several factors including DNA supercoiling, macromolecular crowding and nucleoid associated proteins (NAPs). NAPs bind to different sites of the genome in sequence specific or non-sequence specific manner and play an important role in DNA compaction as well as regulation. Until recently, few NAPs have been discovered in mycobacteria owing to poor sequence similarities with other histone-like proteins of eubacteria. Several putative NAPs have now been identified in Mycobacteria on the basis of enriched basic residues or histone-like “PAKK” motifs. Here, we investigate mycobacterial Integration Host Factor (mIHF) for its architectural roles as a NAP using atomic force microscopy and DNA compaction experiments. We demonstrate that mIHF binds DNA in a non-sequence specific manner and compacts it by a DNA bending mechanism. AFM experiments also indicate a dual architectural role for mIHF in DNA compaction as well as relaxation. These results suggest a convergent evolution in the mechanism of <i>E. coli</i> and mycobacterial IHF in DNA compaction.</p></div