Global adoption of 6-month drug-resistant TB regimens: Projected uptake by 2026

BACKGROUND

The WHO has issued a call to action urging countries to accelerate the rollout of new WHO-recommended shorter all-oral treatment regimens for drug-resistant TB (DR-TB), which remains a public-health crisis. The all-oral, 6-month BPaL/M regimen comprises 3-4 drugs: pretomanid used in combination with bedaquiline and linezolid, with or without moxifloxacin. This regimen has been recommended by the WHO for use in DR-TB patients instead of ≥9-month (up to 24-month) regimens. This study aims to project this regimen's use, along with its components bedaquiline, pretomanid and linezolid, and other treatments for DR-TB globally through 2026. It is intended to guide global health stakeholders in planning and budgeting for DR-TB interventions. Projected usage could help estimate cost of the individual components of DR-TB regimens over time.

METHODS

Semi-structured interviews were conducted with national TB programme participants in key countries to gather intelligence on established plans and targets for use of various DR-TB treatment regimens from 2023 to 2026. These data informed development of projections for the global use of regimens and drugs.

RESULTS

Consistent global growth in the use of shorter regimens in DR-TB treatment was shown: BPaLM reaching 126,792 patients, BPaL reaching 43,716 patients, and the 9-11-month all-oral bedaquiline-based regimen reaching 13,119 patients by 2026. By 2026, the longer all-oral regimen is projected to be used by 19,262 patients, and individualised treatment regimens by 15,344 patients.

CONCLUSION

The study shows BPaL/M will be used in majority of DR-TB patients by 2024, reaching 78% by 2026. However, national efforts to scale-up, case-finding, monitoring, drug-susceptibility testing, and implementation of new treatments will be essential for ensuring they are accessible to all eligible patients in the coming years and goals for ending TB are met. There is an urgent need to engage communities in capacity building and demand generation.

Effect of Honokiol on culture time and survival of Alzheimer's disease iPSC-derived neurons

Introduction

Patient-derived induced pluripotent stem cells (iPSCs) have been widely used as disease models to test new therapeutic strategies. Moreover, the regenerative potential of stem cells can be improved with the use of biologically active compounds. Our study was designed to explore the effect of honokiol, a small polyphenol molecule extracted from Magnolia officinalis, on the survival and culture time of iPSC-derived neurons from a sporadic Alzheimer's disease (AD) patient. This study aimed to generate iPSCs from peripheral blood mononuclear cells (PBMCs) of an AD patient using episomal plasmids with a nucleofector system and differentiate them into neurons. These iPSC-derived neurons were used to investigate the effect of honokiol extracted from M. officinalis on their survival and long-term cultures.

Methods

IPSCs were generated from PBMCs of an AD patient by introducing Oct-3/4, Sox2, Klf4, L-Myc, and Lin28 using NucleofectorTM Technology. Differentiation of neurons derived from iPSCs was carried out using inducers and recognized by biomarkers. The viability of iPSC-derived neurons with the addition of honokiol extracted from the bark of M. officinalis was determined by the MTT analytical kit.

Results

IPSCs were generated by reprogramming AD patient-derived PBMCs and subsequently converted into neurons. The survival and growth of iPSC-derived neurons were significantly enhanced by adding honokiol in the experiment conditions.

Conclusion

AD iPSC-derived neurons had a high viability rate when cultured in the presence of honokiol. These results have shown that AD iPSC-derived neurons can be an excellent model for screening neurotrophic agents and improving the conditions for long-term cultures of human iPSC-derived neurons. Honokiol proves to be a potential candidate for cellular therapeutics against neurodegenerative disorders.

Green synthesis of a photocatalyst Ag/TiO2 nanocomposite using Cleistocalyx operculatus leaf extract for degradation of organic dyes

Green synthesis has emerged as a sustainable approach for the fabrication of nanomaterials in the last few decades. Leaf extracts have been considered low-cost and highly efficient reactants for the synthesis of nanoparticles. In this study, an aqueous extract of Cleistocalyx operculatus leaves was employed as a reductant to synthesize Ag/TiO₂ nanocomposites. The morphology, structure, and interface interaction of the Ag/TiO₂ nanocomposites were investigated by (i) X-ray diffraction (XRD) to determine the crystallinity, (ii) scanning electron microscopy (SEM) to determine the morphologies, (iii) energy dispersive X-ray spectroscopy (EDX) to determine the elemental composition and distribution, and (iv) diffuse reflectance spectroscopy (DRS) to understand the optical properties. The results showed that Ag nanoparticles (AgNPs) with particle sizes of 20-40 nm homogeneously covered the surface of the TiO₂ nanoparticles. The green-synthesized Ag/TiO₂ nanocomposite also exhibited an excellent photodegradation ability for Rhodamine B with a removal percentage up to 91.4% after 180 min of photocatalytic reaction.

In vitro osteogenic activities of sulfated derivative of polysaccharide extracted from Tamarindus indica L

Osteoporosis, one of the most serious public health concerns caused by an imbalance between bone resorption and bone formation, has a major impact on the population. Therefore, finding the effective osteogenic compounds for the treatment of osteoporosis is a promising research approach. In our study, tamarind (Tamarindus indica L.) seed polysaccharide (TSP) extracted from tamarind seed was subjected to synthesize its sulfate derivatives. The ¹H NMR, FT-IR, SEM, monosaccharide compositions and elemental analysis data revealed that tamarind seed polysaccharide sulfate (TSPS) was successfully prepared. As the result, TSPS showed potent effects on inducing osteoblast differentiation via increasing alkaline phosphatase (ALP) activity up to 20% after 10 days and bone mineralization approximately 58% after four weeks at concentration of 20 μg/mL, whereas no statistically increase for both ALP activity and bone mineralization was observed in TSP treatment. Furthermore, TSPS enhanced expression of several marker genes in bone formation. Overall, the obtained data provided novelty on osteogenic compounds originated from TSP of T. indica, as well as scientific fundamentals on drug development and bone tissue engineering for the treatment of osteoporosis and other bone-related diseases.

Hypoglycemic activity of the ethyl acetate extract from Smilax glabra Roxb in mice: Biochemical and histopathological studies

Objectives

This research was carried out to investigate the hypoglycemic activity of the ethyl acetate (EtOAc) extract from the roots of Smilax glabra Roxb, which strongly exhibit inhibitory activity against α-glucosidase and α-amylase on in vivo type 2 diabetic model.

Materials and Methods

Column chromatography combined with crystallization was used to isolate the active fraction and compounds. Chemical structures of the compounds were determined based on the analysis of the spectroscopic data and comparison with the literature data. The α-glucosidase inhibitory activity (AGI) and the α-amylase inhibitory activity (AAI) were determined quantitatively spectrophotometrically using p-nitrophenyl α-D-glucopyranoside and soluble starch as substrates, respectively. The hypoglycemic activity was examined by evaluating its effects on glucose and insulin levels, insulin resistance, and histopathology of the pancreatic islets and livers in diabetic induced mice administrated with nicotinamide-streptozotocin.

Results

The EtOAc extract and the bioactive compounds astilbin and 5-O-caffeoylshikimic acid in the extract were isolated and confirmed in structures, AGI, and AAI. The treatment at the doses of 500 and 1000 µg/kg of body weight reduced blood glucose levels down to the physiological level of the physical controls in the diabetic mice after two weeks (P<0.05). Moreover, the treatment improved insulin sensitivity. Histopathology analysis showed recovering effects in the size of the pancreatic islets and no damaging effects on the liver after treatment compared with the control group.

Conclusion

Our data suggest that the EtOAc extract possesses hypoglycemic activity and has an antidiabetic potential for therapeutic applications.

Collective almost synchronization-based model to extract and predict features of EEG signals

Understanding the brain is important in the fields of science, medicine, and engineering. A promising approach to better understand the brain is through computing models. These models were adjusted to reproduce data collected from the brain. One of the most commonly used types of data in neuroscience comes from electroencephalography (EEG), which records the tiny voltages generated when neurons in the brain are activated. In this study, we propose a model based on complex networks of weakly connected dynamical systems (Hindmarsh–Rose neurons or Kuramoto oscillators), set to operate in a dynamic regime recognized as Collective Almost Synchronization (CAS). Our model not only successfully reproduces EEG data from both healthy and epileptic EEG signals, but it also predicts EEG features, the Hurst exponent, and the power spectrum. The proposed model is able to forecast EEG signals 5.76 s in the future. The average forecasting error was 9.22%. The random Kuramoto model produced the outstanding result for forecasting seizure EEG with an error of 11.21%.

Monitoring ADP/ATP ratio in yeast cells using the fluorescent-protein reporter PercevalHR

PercevalHR (Perceval High Resolution) is an artificially designed fluorescent protein, which changes its excitation spectrum based on the ADP/ATP ratio of the environment. Here we demonstrated that PercevalHR can be used for monitoring energy status of Saccharomyces cerevisiae cells, which are affected by diauxic shift and mitochondria inhibition, in a non-invasive and non-destructive manner.

α-Mangostin disrupts the development of Streptococcus mutans biofilms and facilitates its mechanical removal

α-Mangostin (αMG) has been reported to be an effective antimicrobial agent against planktonic cells of Streptococcus mutans, a biofilm-forming and acid-producing cariogenic organism. However, its anti-biofilm activity remains to be determined. We examined whether αMG, a xanthone purified from Garcinia mangostana L grown in Vietnam, disrupts the development, acidogenicity, and/or the mechanical stability of S. mutans biofilms. Treatment regimens simulating those experienced clinically (twice-daily, 60 s exposure each) were used to assess the bioactivity of αMG using a saliva-coated hydroxyapatite (sHA) biofilm model. Topical applications of early-formed biofilms with αMG (150 µM) effectively reduced further biomass accumulation and disrupted the 3D architecture of S. mutans biofilms. Biofilms treated with αMG had lower amounts of extracellular insoluble and intracellular iodophilic polysaccharides (30-45%) than those treated with vehicle control (P<0.05), while the number of viable bacterial counts was unaffected. Furthermore, αMG treatments significantly compromised the mechanical stability of the biofilm, facilitating its removal from the sHA surface when subjected to a constant shear stress of 0.809 N/m2 (>3-fold biofilm detachment from sHA vs. vehicle-treated biofilms; P<0.05). Moreover, acid production by S. mutans biofilms was disrupted following αMG treatments (vs. vehicle-control, P<0.05). The activity of enzymes associated with glucan synthesis, acid production, and acid tolerance (glucosyltransferases B and C, phosphotransferase-PTS system, and F1F0-ATPase) were significantly inhibited by αMG. The expression of manL, encoding a key component of the mannose PTS, and gtfB were slightly repressed by αMG treatment (P<0.05), while the expression of atpD (encoding F-ATPase) and gtfC genes was unaffected. Hence, this study reveals that brief exposures to αMG can disrupt the development and structural integrity of S. mutans biofilms, at least in part via inhibition of key enzymatic systems associated with exopolysaccharide synthesis and acidogenicity. αMG could be an effective anti-virulence additive for the control and/or removal of cariogenic biofilms.

Antimicrobial actions of benzimidazoles against oral streptococci

BACKGROUND/AIM

Benzimidazoles, such as lansoprazole and omeprazole, are used extensively as proton-pump inhibitors to control stomach acid secretion and also have antimicrobial actions against Helicobacter pylori. Our objective was to determine whether they are potentially useful antimicrobials against oral bacteria.

METHODS

Streptococcus mutans was our main test organism. It was grown in suspension cultures and biofilms. Standard physiologic assays were used to assess inhibitory actions of benzimidazoles.

RESULTS

Benzimidazoles inhibited acid production by S. mutans in suspensions or biofilms. In pH-drop experiments, lansoprazole at a level of only 0.025 mm irreversibly inhibited acid production from glycolysis. Cell uptake of lansoprazole was found to be very pH sensitive and occurred mainly at pH values below about 5, indicating that the protonated form was taken up. Lansoprazole inhibition of glycolysis could be blocked by 2-mercaptoethanol, which suggests that disulfide bonds form between benzimidazoles and protein targets. Identified targets for benzimidazole inhibition included the phosphoenolpyruvate : sugar phosphotransferase system, the glycolytic enzymes aldolase, glyceraldehyde-3-phosphate dehydrogenase, and lactic dehydrogenase, and enzymes such as urease and arginine deiminase. Lansoprazole increased proton permeabilities of S. mutans cells but did not inhibit F-ATPases. Although cells in biofilms were somewhat less sensitive to the agents than those in suspensions, biofilm glycolysis was still markedly inhibited by 0.1 mm lansoprazole. Benzimidazoles are bactericidal, and the oral anaerobes Fusobacterium nucleatum and Prevotella intermedia were more sensitive to killing than was S. mutans.

CONCLUSION

Benzimidazoles appear to be useful inhibitors of oral bacteria in acid environments such as progressing caries lesions.

Fluoride and organic weak acids as respiration inhibitors for oral streptococci in acidified environments

Oxygen metabolism (respiration) of Streptococcus mutans GS-5 involving NADH oxidases, mainly of the H(2)O-producing type, was found to be acid sensitive, as was NADH oxidase activity of cell extracts. Respiration of intact cells in acidified media was also highly sensitive to fluoride, with a 50% inhibitory concentration of about 0.02 mM at pH 4. In contrast, NADH oxidases in cell extracts were fluoride insensitive. Fluoride inhibition of respiration of intact cells was related to weak-acid effects leading to enhanced proton permeability of cells, cytoplasmic acidification and resultant acid inhibition of NADH oxidases and glycolysis. Organic weak acids, such as indomethacin and benzoate, were also effective inhibitors. H(2)O(2) production by intact cells of Streptococcus sanguis NCTC 10904, a peroxide producer, was similarly inhibited by fluoride or organic weak acids in acidified media. Thus, weak acids act as respiratory inhibitors for oral streptococci indirectly by acidifying the cytoplasm rather than acting as direct inhibitors of NADH oxidases.