Endophytic Microbes from Diverse Wheat Genotypes and Their Potential Biotechnological Applications in Plant Growth Promotion and Nutrient Uptake

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Endophytic microbes residing inside the tissues of plants play a significant role to enhance the growth and...     

Study of Cell Viability and Etiology of Contamination in Decalcified Bone Allograft: A Pilot Study

BackgroundBone allografts can elicit immune responses which is correlated with the presence of Human Leukocyte Antigen (HLA) and cellular DNA. It also has risk of causing occult infection arising out of contamination during its processing and storage. The presence of immunogenic materials like cells, cellular remnants and DNA in a decalcified bone allograft during different phases of processing has never been studied. Present study was conducted to explore- the cell viability using routine Hematoxylin and Eosin, presence of DNA using Feulgen staining and etiology of contamination in decalcified bone allograft during procurement, demineralization and ethanol preservation.MethodsThe harvested bones from patients undergoing hemireplacement/THR/TKR were processed to prepare decalcified bone allografts. The samples during procurement (A), HCL treatment (B) and ethanol preservation (C) were sent for histopathological analysis (number of osteocytes in the maximum density field under 40x and the cells demonstrating presence of DNA on feulgen stain) and microbiological assessment (aerobic/anaerobic/fungal cultures).ResultsHistopathological study demonstrated the presence of osteocytes and other cells like bone marrow, adipocytes, endothelial cells in the decal bone allograft. The average number of osteocytes gradually decreased from 55.47, 9.6, 0.86 in sample A, B, C, respectively. Feulgen staining confirmed the presence of DNA in osteocytes and other cells which decreased both qualitatively and quantitatively in subsequent stages of processing. Rate of contamination demonstrated at the procurement was 6.67% (Staphylococcus aureus). After treatment with HCl (demineralisation), 7.14% of non-contaminated allografts were found contaminated (Staphylococcus epidermidis). None of the remaining 13 non-contaminated allografts showed contamination after storage in ethanol. Overall 13% of the patients had positive cultures on microbiological assessment.ConclusionThe population of osteocytes in the harvested bone reduced significantly after processing with HCl and ethanol preservation. Presence of DNA, demonstrated by using Feulgen staining, was observed in bone marrow cells, adipocytes along with osteocytes which showed quantitative reduction on processing. Hence, antigenicity, conferred by cells and their DNA, reduced significantly after processing of decal bone. Contamination rate of banked decalcified allograft was 13%. Thus, culture and sensitivity tests should be carried out at each step of processing of decal bone allograft.     

How to Regulate Nonbiological Complex Drugs (NBCD) and Their Follow-on Versions: Points to Consider

The aim of this critical review is to reach a global consensus regarding the introduction of follow-on versions of nonbiological complex drugs (NBCD). A nonbiological complex drug is a medicinal product, not being a biological medicine, where the active substance is not a homo-molecular structure, but consists of different (closely related and often nanoparticulate) structures that cannot be isolated and fully quantitated, characterized and/or described by state of the art physicochemical analytical means and where the clinical meaning of the differences is not known. The composition, quality and in vivo performance of NBCD are highly dependent on manufacturing processes of both the active ingredient as well as in most cases the formulation. The challenges posed by the development of follow-on versions of NBCD are illustrated in this paper by discussing the ‘families’ of liposomes, iron–carbohydrate (‘iron–sugar’) drugs and glatiramoids. It is proposed that the same principles for the marketing authorization of copies of NBCD as for biosimilars be used: the need for animal and/or clinical data and the need to show similarity in quality, safety and efficacy. The regulatory approach of NBCD will have to take into consideration the specific characteristics of the drugs, their formulation and manufacturing process and the resulting critical attributes to achieve their desired quality, safety and efficacy. As with the biosimilars, for the NBCD product, family-specific methods should be evaluated and applied where scientifically proven, including sophisticated quality methods, pharmacodynamic markers and animal models. Concerning substitution and interchangeability of NBCD, it is also advisable to take biosimilars as an example, i.e. (1) substitution without the involvement of a healthcare professional should be discouraged to ensure traceability of the treatment of individual patients, (2) keep an individual patient on a specific treatment if the patient is doing well and only switch if unavoidable and (3) monitor the safety and efficacy of the new product if switching occurs.     

Antioxidant and Antimicrobial Potential of Natural Colouring Pigment Derived from Bixa orellana L. Seed Aril

Natural colourants with bio-potential are of great commercial demands as we are moving away from the hazardous and toxic chemical dyes. Bixa orellana L. a representative of Bixaceae is rich in bixin and nor-bixin pigments which could be explored for various applications. In the present study, extraction and characterization of bixin and its associated pigment from the aril of the B. orellana L. seeds were performed using various spectroscopic techniques. Spectroscopic analysis and Gas chromatographic profiling of the pigment were performed to understand the present pigments. Toxicity was evaluated through in silico method. The major component, bixin and nor-bixin were proved to be non-toxic, non-carcinogenic and non-mutagenic through in silico methods. The pigment was found to be a potent antioxidant as well as bactericidal against opportunistic bacteria. It was found that bixin extract was a potential antioxidant and bactericidal agent. Hence it could be used for imparting bactericidal potential for cellulosic materials like papers or textiles in biomedical applications.