A Gelatin-Based Biomimetic Scaffold Promoting Osteogenic Differentiation of Adipose-Derived Mesenchymal Stem Cells.

Background: In bone tissue engineering segment, numerous approaches have been investigated to address critically sized bone defects via 3D scaffolds, as the amount of autologous bone grafts are limited, accompanied with complications on harvesting. Moreover, the use of bone-marrow-derived stem cells is also a limiting factor owing to the invasive procedures involved and the low yield of stem cells. Hence, research is ongoing on the search for an ideal bone graft system promoting bone growth and regeneration. Purpose of the Study: This study aims to develop a unique platform for tissue development via stem cell differentiation towards an osteogenic phenotype providing optimum biological cues for cell adhesion, differentiation and proliferation using biomimetic gelatin-based scaffolds. The use of adipose-derived mesenchymal stem cells in this study also offers an ideal approach for the development of an autologous bone graft. Methods: A gelatin-vinyl acetate-based 3D scaffold system incorporating Bioglass was developed and the osteogenic differentiation of adipose-derived mesenchymal stem cells (ADMSCs) on the highly porous freeze-dried gelatin-vinyl acetate/ Bioglass scaffold (GB) system was analyzed. The physicochemical properties, cell proliferation and viability were investigated by seeding rat adipose tissue-derived mesenchymal stem cells (ADSCs) onto the scaffolds. The osteogenic differentiation potential of the ADMSC seeded GeVAc/bioglass system was assessed using calcium deposition assay and bone-related protein and genes and comparing with the 3D Gelatin vinyl acetate coppolymer (GeVAc) constructs. Results and Conclusion: According to the findings, the 3D porous GeVAc/bioglass scaffold can be considered as a promising matrix for bone tissue regeneration and the 3D architecture supports the differentiation of the ADMSCs into osteoblast cells and enhances the production of mineralized bone matrix.

Pluronic F127 composite hydrogel for the repair of contraction suppressed full-thickness skin wounds in a rabbit model.

Hydrogels are commonly used as carriers for cell delivery due to their similarities to the extracellular matrix. A contraction-suppressed full-thickness wound model was used to evaluate the therapeutic potential of Pluronic F127 (PF127) hydrogel loaded with adipose-derived stromal vascular fraction (AdSVF), mesenchymal stem cells (AdMSC), and conditioned media (AdMSC-CM) for the repair of wounds in a rabbit model. The experimental study was conducted on forty-eight healthy adult New Zealand white rabbits randomly divided into eight groups with six animals each and treated with AdSVF, AdMSC, and AdMSC-CM as an injectable or topical preparation. The healing potential of different adipose-derived cell-based and cell-free therapeutics was evaluated based on percentage wound healing, period of epithelialization, epidermal thickness, scar evaluation, histopathology analysis, histochemical evaluation, immunohistochemistry (collagen type I), and hydroxyproline assay by comparing with the positive and negative control. Collagen density analysis using different staining methods, immunohistochemistry, and hydroxyproline assay consistently showed that delivering AdMSC and AdMSC-CM in PF127 hydrogel enhanced epithelialization, collagen production, and organization, contributing to improved tissue strength and quality. Even though allogeneic AdSVF was found to promote wound healing in rabbits, it has a lower potential than AdMSC and AdMSC-CM. The wound healing potential of AdMSC and AdMSC-CM was enhanced when loaded in PF127 hydrogel and applied topically. Even though wounds treated with AdMSC outperformed AdMSC-CM, a significant difference in the healing quality was not observed in most instances, indicating almost similar therapeutic potential. The findings indicate that the wound healing potential of AdMSC and AdMSC-CM was enhanced when loaded in PF127 hydrogel and applied topically. These treatments promoted collagen production, tissue organization, and epidermal regeneration, ultimately improving overall healing outcomes.

Operator impact assessment on qualitative and quantitative parameters of canine platelet-rich plasma.

Platelet-rich plasma (PRP) has emerged as a cornerstone in veterinary regenerative medicine. The present study evaluated the impact of the operator on the qualitative and quantitative features of non-activated PRP derived from canine whole blood. Blood was collected in anticoagulant acid citrate dextrose from twelve healthy adult dogs and PRP was prepared according to the double-spin method. Both operators followed an identical protocol and utilized the same equipment for PRP preparation from the pooled blood samples. The resulting PRP underwent characterization, classification and coding based on minimum reporting standards. The consistency and internal reliability of different parameters were also assessed using the intraclass correlation coefficient and Cronbach's alpha values. Variables such as white blood cell (WBC) concentration, relative WBC composition and mean platelet volume (MPV) showed poor reliability, and WBC concentration and MPV also had unacceptable internal consistency. Significant differences were observed in several qualitative and quantitative parameters of the prepared PRP, highlighting the influence of the operator even when the same protocol and equipment were used. Our study has direct implications to regenerative medicine, reinforcing the urgency to set minimum requirements for reporting PRP in research studies.

Minimal criteria for reporting mesenchymal stem cells in veterinary regenerative medicine.

The widespread application of mesenchymal stem cells (MSCs) in veterinary regenerative medicine highlights their promising therapeutic potential. However, the lack of standardized characterization and reporting practices across studies poses a significant challenge, compromising the assessment of their safety and efficacy. While criteria established for human MSCs serve as a foundation, the unique characteristics of animal-derived MSCs warrant updated guidelines tailored to veterinary medicine. A recent position statement outlining minimal reporting criteria for MSCs in veterinary research reflects efforts to address this need, aiming to enhance research quality and reproducibility. Standardized reporting criteria ensure transparency, facilitate evidence synthesis, and promote best practices adoption in MSC isolation, characterization, and administration. Adherence to minimal reporting criteria is crucial for maintaining scientific rigor and advancing the field of veterinary regenerative medicine. Ongoing collaboration among stakeholders is essential for effective implementation and adherence to updated guidelines, fostering excellence and innovation in MSC-based therapies for animal patients.

Mesenchymal stem cells for cartilage regeneration: Insights into molecular mechanism and therapeutic strategies.

The use of mesenchymal stem cells (MSCs) in cartilage regeneration has gained significant attention in regenerative medicine. This paper reviews the molecular mechanisms underlying MSC-based cartilage regeneration and explores various therapeutic strategies to enhance the efficacy of MSCs in this context. MSCs exhibit multipotent capabilities and can differentiate into various cell lineages under specific microenvironmental cues. Chondrogenic differentiation, a complex process involving signaling pathways, transcription factors, and growth factors, plays a pivotal role in the successful regeneration of cartilage tissue. The chondrogenic differentiation of MSCs is tightly regulated by growth factors and signaling pathways such as TGF-ß, BMP, Wnt/ß-catenin, RhoA/ROCK, NOTCH, and IHH (Indian hedgehog). Understanding the intricate balance between these pathways is crucial for directing lineage-specific differentiation and preventing undesirable chondrocyte hypertrophy. Additionally, paracrine effects of MSCs, mediated by the secretion of bioactive factors, contribute significantly to immunomodulation, recruitment of endogenous stem cells, and maintenance of chondrocyte phenotype. Pre-treatment strategies utilized to potentiate MSCs, such as hypoxic conditions, low-intensity ultrasound, kartogenin treatment, and gene editing, are also discussed for their potential to enhance MSC survival, differentiation, and paracrine effects. In conclusion, this paper provides a comprehensive overview of the molecular mechanisms involved in MSC-based cartilage regeneration and outlines promising therapeutic strategies. The insights presented contribute to the ongoing efforts in optimizing MSC-based therapies for effective cartilage repair.

FDA Approval Summary: Dabrafenib in Combination with Trametinib for BRAFV600E Mutation-Positive Low-Grade Glioma.

On March 16, 2023, the FDA approved dabrafenib in combination with trametinib (Tafinlar, Mekinist; Novartis Pharmaceuticals Corporation) for the treatment of pediatric patients with low-grade glioma (LGG) with a BRAFV600E mutation who require systemic therapy. FDA also approved oral formulations of both drugs suitable for patients who cannot swallow pills. This approval was based on the LGG cohort from study CDRB436G2201 (NCT02684058), a multicenter, open-label trial in which pediatric patients with LGG with a BRAFV600E mutation were randomly assigned 2:1 to dabrafenib plus trametinib (D+T) or carboplatin plus vincristine (C+V). The overall response rate (ORR) by independent review based on Response Assessment in Neuro-oncology LGG (2017) criteria was assessed in 110 patients randomly assigned to D+T (n = 73) or C+V (n = 37). ORR was 47% [95% confidence interval (CI), 35-59] in the D+T arm and 11% (95% CI, 3.0-25) in the C+V arm. Duration of response (DOR) was 23.7 months (95% CI, 14.5-NE) in the D+T arm and not estimable (95% CI, 6.6- NE) in the C+V arm. Progression-free survival (PFS) was 20.1 months (95% CI: 12.8, NE) and 7.4 months (95% CI, 3.6- 11.8) [HR, 0.31 (95% CI, 0.17-0.55); P < 0.001] in the D+T and C+V arms, respectively. The most common (>20%) adverse reactions were pyrexia, rash, headache, vomiting, musculoskeletal pain, fatigue, diarrhea, dry skin, nausea, hemorrhage, abdominal pain, and dermatitis acneiform. This represents the first FDA approval of a systemic therapy for the first-line treatment of pediatric patients with LGG with a BRAFV600E mutation.

Therapeutic applications of canine platelets and their derivatives: a narrative review.

Platelets contain a multitude of growth factors and play a crucial role in physiological processes such as thrombogenesis, tissue repair, and angiogenesis. As a result, platelet-derived products have significant potential for efficient utilization in the realm of regenerative medicine due to their therapeutic and biological attributes. Numerous studies have already substantiated the therapeutic viability of platelets in various canine ailments. The existing literature indicates a substantial surge in the clinical application of canine platelets, positioning platelet-derived products as a viable alternative to conventional therapeutic agents. Platelet concentrates, including platelet-rich plasma and platelet-rich fibrin are commonly used as a therapeutic modality in clinical cases. These therapeutic derivatives exhibit effectiveness in tissue regeneration and can serve as complementary therapies. Notably, they offer a cost-effective and easily accessible therapeutic option, which has demonstrated its benefits in chronic inflammatory disorders such as osteoarthritis and tendinitis, ophthalmic conditions, wound healing, and mandibular injuries in canine patients. The broad spectrum of therapeutic effects displayed by platelets is providing researchers with novel perspectives for crafting therapeutic models in future investigations. This review centers on exploring the therapeutic potential of canine platelets across diverse disorders. Further exploration into platelet products, encompassing their preparation and applicability in canine medicine, is imperative. These inquiries hold the promise of unveiling fresh horizons for the domain of regenerative medicine.

ChatGPT and artificial hallucinations in stem cell research: assessing the accuracy of generated references - a preliminary study.

Stem cell research has the transformative potential to revolutionize medicine. Language models like ChatGPT, which use artificial intelligence (AI) and natural language processing, generate human-like text that can aid researchers. However, it is vital to ensure the accuracy and reliability of AI-generated references. This study assesses Chat Generative Pre-Trained Transformer (ChatGPT)'s utility in stem cell research and evaluates the accuracy of its references. Of the 86 references analyzed, 15.12% were fabricated and 9.30% were erroneous. These errors were due to limitations such as no real-time internet access and reliance on preexisting data. Artificial hallucinations were also observed, where the text seems plausible but deviates from fact. Monitoring, diverse training, and expanding knowledge cut-off can help to reduce fabricated references and hallucinations. Researchers must verify references and consider the limitations of AI models. Further research is needed to enhance the accuracy of such language models. Despite these challenges, ChatGPT has the potential to be a valuable tool for stem cell research. It can help researchers to stay up-to-date on the latest developments in the field and to find relevant information.

Evaluation of bone marrow-derived mesenchymal stem cells with eggshell membrane for full-thickness wound healing in a rabbit model.

Biomaterials capable of managing wounds should have essential features like providing a natural microenvironment for wound healing and as support material for stimulating tissue growth. Eggshell membrane (ESM) is a highly produced global waste due to increased egg consumption. The unique and fascinating properties of ESM allow their potential application in tissue regeneration. The wound healing capacity of bone marrow-derived mesenchymal stem cells (BM-MSCs), ESM, and their combination in rabbits with full-thickness skin defect (2 × 2 cm2) was evaluated. Twenty-five clinically healthy New Zealand White rabbits were divided into five groups of five animals each, with group A receiving no treatment (control group), group B receiving only fibrin glue (FG), group C receiving FG and ESM as a dressing, group D receiving FG and BM-MSCs, and group E receiving a combination of FG, ESM, and BM-MSCs. Wound healing was assessed using clinical, macroscopical, photographic, histological, histochemical, hematological, and biochemical analysis. Macroscopic examination of wounds revealed that healing was exceptional in group E, followed by groups D and C, compared to the control group. Histopathological findings revealed improved quality and a faster rate of healing in group E compared to groups A and B. In addition, healing in group B treated with topical FG alone was nearly identical to that in control group A. However, groups C and D showed improved and faster recovery than control groups A and B. The macroscopic, photographic, histological, and histochemical evaluations revealed that the combined use of BM-MSCs, ESM, and FG had superior and faster healing than the other groups.

First-Principles Insights into the Relative Stability, Physical Properties, and Chemical Properties of MoSe2.

A fascinating transition-metal dichalcogenide (TMDC) compound, MoSe2, has attracted a lot of interest in electrochemical, photocatalytic, and optoelectronic systems. However, detailed studies on the structural stability of the various MoSe2 polymorphs are still lacking. For the first time, the relative stability of 11 different MoSe2 polymorphs (1H, 2H, 3Ha, 3Hb, 2T, 4T, 2R1, 1T1, 1T2, 3T, and 2R2) is proposed, and a detailed analysis of these polymorphs is carried out by employing the first-principles calculations based on density functional theory (DFT). We computed the physical properties of the polymorphs such as band structure, phonon, and elastic constants to examine the viability for real-world applications. The electronic properties of the involved polymorphs were calculated by employing the hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE06). The energy band gap of the polymorphs (1H, 2H, 3Ha, 3Hb, 2T, 4T, and 2R1) is in the range of 1.6-1.8 eV, coinciding with the experimental value for the polymorph 2H. The covalent bonding nature of MoSe2 is analyzed from the charge density, charge transfer, and electron localization function. Among the 11 polymorphs, 1H, 2H, 2T, and 3Hb polymorphs are predicted as stable polymorphs based on the calculation of the mechanical and dynamical properties. Even though the 4T and 3Ha polymorphs' phonons are stable, they are mechanically unstable; hence, they are considered to be under a metastable condition. Additionally, we computed the direction-dependent elastic moduli and isotropic factors for both mechanically and dynamically stable polymorphs. Stable polymorphs are analyzed spectroscopically using IR and Raman spectra. The thermal stability of the polymorphs is also studied.

Regulatory utility of physiologically-based pharmacokinetic modeling to support alternative bioequivalence approaches and risk assessment: A workshop summary report.

This report summarizes the proceedings for day 2 sessions 1 and 3 of the 2-day public workshop entitled "Regulatory Utility of Mechanistic Modeling to Support Alternative Bioequivalence Approaches," a jointly sponsored workshop by the US Food and Drug Administration (FDA) and the Center for Research on Complex Generics (CRCG). The aims of this workshop were: (1) to discuss how mechanistic modeling, including physiologically-based pharmacokinetic (PBPK) modeling and simulation, can support product development, and regulatory submissions; (2) to share the current state of mechanistic modeling for bioequivalence (BE) assessment through case studies; (3) to establish a consensus on best practices for using PBPK modeling for BE assessment to help drive further investment by the generic drug industry into mechanistic modeling and simulation; and (4) to introduce the concept of a Model Master File to improve model-sharing. The theme of day 2 covered PBPK absorption model for oral products as an alternative BE approach and a tool for supporting risk assessment and biowaiver (session 1), oral PBPK for evaluating the impact of food on BE (session 2), successful cases, and challenges for oral PBPK (session 3). This report summarizes the topics of the presentations of day 2 sessions 1 and session 3 from FDA, academia, and pharmaceutical industry, including the current status of oral PBPK, case examples as well as the challenges and opportunities in this area. In addition, panel discussions on the utility of oral PBPK in both new drugs and generic drugs from regulatory and industry perspective are also summarized.

Examining the role of nickel and NiTi nanoparticles promoting inflammation and angiogenesis.

Nickel titanium (NiTi, or Nitinol) alloy is used in several biomedical applications, including cardiac, peripheral vascular, and fallopian tube stents. There are significant biocompatibility issues of metallic implants to nickel ions and nano-/micro-sized alloy particles. Our laboratories have recently shown that microscale CoCr wear particles from metal-on-metal hips crosslink with the innate immune signaling Toll-like receptor 4 (TLR4), prompting downstream signaling that results in interleukin (IL)-1ß and IL-8 gene expression. In vivo, NiTi alloy can also generate wear particles on the nanoscale (NP) that have thus far not been studied for their potential to induce inflammation and angiogenesis that can, in turn, contribute to implant (e.g. stent) failure. Earlier studies by others demonstrated that nickel could induce contact hypersensitivity by crosslinking the human, but not the mouse, TLR4. In the present work, it is demonstrated that NiCl2 ions and NiTi nanoparticles induce pro-inflammatory and pro-angiogenic cytokine/chemokine expression in human endothelial and monocyte cell lines in vitro. These observations prompt concerns about potential mechanisms for stent failure. The data here showed a direct correlation between intracellular uptake of Ni2+ and generation of reactive oxygen species. To determine a role for nickel and NiTi nanoparticles in inducing angiogenesis in vivo, 1-cm silicone angioreactors were implanted subcutaneously into athymic (T-cell-deficient) nude mice. The angioreactors contained Matrigel (a gelatinous protein mixture that resembles extracellular matrix) in addition to one of the following: PBS (negative control), VEGF/FGF-2 (positive control), NiCl2, or NiTi NP. The implantation of angioreactors represents a potential tool for quantification of angiogenic potentials of medical device-derived particles and ions in vivo. By this approach, NiTi NP were found to be markedly angiogenic, while Ni2+ was less-so. The angioreactors may provide a powerful tool to examine if debris shed from medical devices may promote untoward biological effects.

Drosophila Evolution over Space and Time (DEST): A New Population Genomics Resource.

Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome data sets from natural populations of this species have been published over the last years. A major challenge is the integration of disparate data sets, often generated using different sequencing technologies and bioinformatic pipelines, which hampers our ability to address questions about the evolution of this species. Here we address these issues by developing a bioinformatics pipeline that maps pooled sequencing (Pool-Seq) reads from D. melanogaster to a hologenome consisting of fly and symbiont genomes and estimates allele frequencies using either a heuristic (PoolSNP) or a probabilistic variant caller (SNAPE-pooled). We use this pipeline to generate the largest data repository of genomic data available for D. melanogaster to date, encompassing 271 previously published and unpublished population samples from over 100 locations in >20 countries on four continents. Several of these locations have been sampled at different seasons across multiple years. This data set, which we call Drosophila Evolution over Space and Time (DEST), is coupled with sampling and environmental metadata. A web-based genome browser and web portal provide easy access to the SNP data set. We further provide guidelines on how to use Pool-Seq data for model-based demographic inference. Our aim is to provide this scalable platform as a community resource which can be easily extended via future efforts for an even more extensive cosmopolitan data set. Our resource will enable population geneticists to analyze spatiotemporal genetic patterns and evolutionary dynamics of D. melanogaster populations in unprecedented detail.

Development of a novel atrophic non-union model in rabbits: A preliminary study.

BACKGROUND AND AIM: The currently available atrophic non-union models rely on wide segmental excision of bone diaphysis to impede the process of healing but lack resemblance to the clinical scenario. The present study focused on developing an in vivo model of atrophic non-union fracture in rabbit radius that can replicate the clinical scenario. MATERIALS AND METHODS: The atrophic non-union fracture model was developed by creating a 10 mm segmental bone defect in the radial diaphysis of five adult New Zealand White rabbits. The periosteum (2 mm) of the cut bone ends was cauterized using electrocautery to induce atrophy. Atrophic non-union was confirmed using radiographic and histologic evaluations on 30th postoperative day. RESULTS: The radiographic signs of healing were completely absent in all the rabbits on 30th postoperative day, indicating inert bone ends. Histological findings further confirmed the presence of inert bone ends, indicating the development of atrophic non-union. CONCLUSION: The combination of the segmental bone defect, electrocautery induced thermal damage of bone end periosteum, and delayed treatment can induce the development of atrophic non-union fracture model in rabbits that can replicate the clinical scenario.

Classification and coding of platelet-rich plasma derived from New Zealand white rabbits for tissue engineering and regenerative medicine applications.

BACKGROUND AND OBJECTIVE: Platelet-rich plasma (PRP) is a category of platelet concentrate that has been widely used as a therapeutic modality in musculoskeletal medicine. The present study was conducted to classify and code the non-activated platelet-rich plasma (nPRP) derived from New Zealand white rabbits for tissue engineering and other regenerative medicine applications. METHODS: PRP was prepared from the whole blood by double centrifugation protocol using a laboratory centrifuge. The prepared nPRP was characterized using the parameters such as platelet dose, the relative composition of platelets, WBC, and RBC. The production protocol was described using the parameters such as platelet enrichment factor, factor increase in WBC concentration, platelet capture efficiency, WBC-reducing efficiency, and RBC-reducing efficiency. The nPRP was also classified and coded using the most recent and universally accepted classification and coding systems. RESULTS: The non-activated leukocyte-poor red cell-rich PRP had an average platelet count of 1875.75 × 109/L, which is higher than the basal platelet concentration in the whole blood. Furthermore, the protocol used in this study has a mean platelet capture efficiency of 47.43 ± 6.42%. CONCLUSION: The protocol described in this study can be used to prepare non-activated leukocyte-poor red cell-rich PRP (Red-PRP IC1) from rabbits that can be coded as 318-00-00.

An efficient medical image encryption using hybrid DNA computing and chaos in transform domain.

In this growing era, a massive amount of digital electronic health records (EHRs) are transferred through the open network. EHRs are at risk of a myriad of security threats, to overcome such threats, encryption is a reliable technique to secure data. This paper addresses an encryption algorithm based on integer wavelet transform (IWT) blended with deoxyribo nucleic acid (DNA) and chaos to secure the digital medical images. The proposed work comprises of two phases, i.e. a two-stage shuffling phase and diffusion phase. The first stage of shuffling starts with initial block confusion followed by row and column shuffling of pixels as the second stage. The pixels of the shuffled image are circularly shifted bitwise at the first stage of diffusion to enhance the security of the system against differential attack. The second stage of diffusion operation is based on DNA coding and DNA XOR operations. The experimental analyses have been carried out with 100 DICOM test images of 16-bit depth to evaluate the strength of the algorithm against statistical and differential attacks. By the results, the maximum entropy has been obtained an average of 15.79, NPCR of 99.99, UACI of 33.31, and larger keyspace of 10140, which infer that our technique overwhelms various other state-of-the-art techniques.

A robust medical image encryption in dual domain: chaos-DNA-IWT combined approach.

Today's technological era, the booming desire for e-healthcare has inflated the attention towards the security of data from cyber attacks. As the digital medical images are transferred over the public network, there is a demand to shield an adequate level of protection. One of the prominent techniques is encryption which secures the medical images. This paper recommends a DICOM image encryption based upon chaotic attractors on frequency domain by integer wavelet transform (IWT) and fused with deoxyribonucleic acid (DNA) sequence on the spatial domain. The proposed algorithm uses a chaotic 3D Lorenz attractor and logistic map to generate pseudo-random keys for encryption. The algorithm involves subsequent stages, i.e. permutation, substitution, encoding, complementary and decoding. To endorse the resistance of the proposed algorithm, various analyses have been examined for 256 × 256 DICOM images by achieving an average entropy of 7.99, larger keyspace of 10238 and non-zero correlation. The overall results confirm that the proposed algorithm is robust against the brute force attacks. Graphical abstract.

Discordance in Xpert® MTB/RIF assay results among low bacterial load clinical specimens in Bangladesh.

BACKGROUND: The Xpert® MTB/RIF assay detects Mycobacterium tuberculosis (MTB) and rifampicin (RIF) resistance. RIF-resistant (RIF-R) MTB cases detected using Xpert on sputum specimens at three private-sector TB screening centres in Dhaka, Bangladesh, were subjected to consecutive confirmatory Xpert testing, the results of which were MTB-positive/RIF-susceptible, MTB-positive/RIF-indeterminate or MTB-negative. OBJECTIVE: To assess the possible causes of discordant MTB and RIF-R results. METHODS: Discordant confirmatory Xpert test results were subjected to further investigations using the GenoType® MTBDRplus assay, culture and rpoB gene sequencing. RESULTS: The confirmatory Xpert test was performed on a remnant or a second specimen collected from individuals with an initial RIF-R result (n = 69); 22 (32%) results were discordant, 20 of which had an 'MTB detected-very low' result. Further investigations were mostly concordant with the confirmatory Xpert test. Average variability in paired cycle threshold (Ct) values were higher in 'MTB detected-very low' results vs. specimens with low, medium or high detected MTB results (P < 0.05); discordant results were mostly observed in specimens with 'MTB detected-very low' (20/22). CONCLUSIONS: Repeating the Xpert test and comparing with other available tests should be considered in case of 'MTB detected-very low, RIF resistance detected' results on Xpert.

Effects of patchouli and cinnamon essential oils on biofilm and hyphae formation by Candida species.

The prevalence and fatality rates with biofilm-associated candidal infections have remained a challenge to the medical fraternity despite major advances in the field of antifungal therapy. Traditionally, essential oils (EOs) from the aromatic plants have been found to be excellent therapeutic agents to treat fungal ailments. The present study explores the antivirulent and antibiofilm effects of under explored leaf EOs of Indian patchouli EO extracted from Pogostemon heyneanus (PH), Indian cassia from Cinnamomum tamala (CT) and camphor EO from C. camphora (CC) against Candida species. The EOs were investigated for its efficacy to disrupt the young and preformed Candida spp. biofilms and to inhibit the yeast to hyphal transition, a hallmark virulent trait of C. albicans. The ability of these EOs to inhibit metabolically active cells was assessed through XTT assay. Of these three EOs, CT EO showed enhanced biofilm inhibition than others and hence it was further selected to study its biomass inhibition potential and exopolysaccharide layer disruption ability. The CT EO reduced the biomass of the preformed biofilms of all three Candida strains, which was supported by confocal microscopy. It also disrupted the exopolysaccharide layer of the Candida strains as shown by scanning electron microscopy. The present findings validate the effectiveness of EOs against the virulence of Candida spp. and emphasize the pharmaceutical potential of several native but yet unexplored wild aromatic plants in the prospect of therapeutic application.