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1.
Nature ; 603(7900): 315-320, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35197633

RESUMO

Colibactin is a chemically unstable small-molecule genotoxin that is produced by several different bacteria, including members of the human gut microbiome1,2. Although the biological activity of colibactin has been extensively investigated in mammalian systems3, little is known about its effects on other microorganisms. Here we show that colibactin targets bacteria that contain prophages, and induces lytic development through the bacterial SOS response. DNA, added exogenously, protects bacteria from colibactin, as does expressing a colibactin resistance protein (ClbS) in non-colibactin-producing cells. The prophage-inducing effects that we observe apply broadly across different phage-bacteria systems and in complex communities. Finally, we identify bacteria that have colibactin resistance genes but lack colibactin biosynthetic genes. Many of these bacteria are infected with predicted prophages, and we show that the expression of their ClbS homologues provides immunity from colibactin-triggered induction. Our study reveals a mechanism by which colibactin production could affect microbiomes and highlights a role for microbial natural products in influencing population-level events such as phage outbreaks.


Assuntos
Bactérias , Toxinas Bacterianas , Peptídeos , Policetídeos , Prófagos , Ativação Viral , Bactérias/efeitos dos fármacos , Bactérias/virologia , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/farmacologia , Bacteriólise/efeitos dos fármacos , Interações Microbianas/efeitos dos fármacos , Peptídeos/metabolismo , Peptídeos/farmacologia , Policetídeos/metabolismo , Policetídeos/farmacologia , Prófagos/efeitos dos fármacos , Prófagos/fisiologia , Resposta SOS em Genética/efeitos dos fármacos , Ativação Viral/efeitos dos fármacos
2.
J Biomed Sci ; 31(1): 65, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943128

RESUMO

BACKGROUND: Enterovirus 71 (EV-A71) causes Hand, Foot and Mouth Disease (HFMD) in children and has been associated with neurological complications. The molecular mechanisms involved in EV-A71 pathogenesis have remained elusive. METHODS: A siRNA screen in EV-A71 infected-motor neurons was performed targeting 112 genes involved in intracellular membrane trafficking, followed by validation of the top four hits using deconvoluted siRNA. Downstream approaches including viral entry by-pass, intracellular viral genome quantification by qPCR, Western blot analyses, and Luciferase reporter assays allowed determine the stage of the infection cycle the top candidate, RAB11A was involved in. Proximity ligation assay, co-immunoprecipitation and multiplex confocal imaging were employed to study interactions between viral components and RAB11A. Dominant negative and constitutively active RAB11A constructs were used to determine the importance of the protein's GTPase activity during EV-A71 infection. Mass spectrometry and protein interaction analyses were employed for the identification of RAB11A's host interacting partners during infection. RESULTS: Small GTPase RAB11A was identified as a novel pro-viral host factor during EV-A71 infection. RAB11A and RAB11B isoforms were interchangeably exploited by strains from major EV-A71 genogroups and by Coxsackievirus A16, another major causative agent of HFMD. We showed that RAB11A was not involved in viral entry, IRES-mediated protein translation, viral genome replication, and virus exit. RAB11A co-localized with replication organelles where it interacted with structural and non-structural viral components. Over-expression of dominant negative (S25N; GDP-bound) and constitutively active (Q70L; GTP-bound) RAB11A mutants had no effect on EV-A71 infection outcome, ruling out RAB11A's involvement in intracellular trafficking of viral or host components. Instead, decreased ratio of intracellular mature viral particles to viral RNA copies and increased VP0:VP2 ratio in siRAB11-treated cells supported a role in provirion maturation hallmarked by VP0 cleavage into VP2 and VP4. Finally, chaperones, not trafficking and transporter proteins, were found to be RAB11A's top interacting partners during EV-A71 infection. Among which, CCT8 subunit from the chaperone complex TRiC/CCT was further validated and shown to interact with viral structural proteins specifically, representing yet another novel pro-viral host factor during EV-A71 infection. CONCLUSIONS: This study describes a novel, unconventional role for RAB11A during viral infection where it participates in the complex process of virus morphogenesis by recruiting essential chaperone proteins.


Assuntos
Enterovirus Humano A , Proteínas rab de Ligação ao GTP , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab de Ligação ao GTP/genética , Enterovirus Humano A/genética , Enterovirus Humano A/fisiologia , Enterovirus Humano A/metabolismo , Humanos , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Replicação Viral
3.
Gut ; 72(9): 1651-1663, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36918265

RESUMO

OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer mortality, with ARID1A being the second most frequently mutated driver gene in GC. We sought to decipher ARID1A-specific GC regulatory networks and examine therapeutic vulnerabilities arising from ARID1A loss. DESIGN: Genomic profiling of GC patients including a Singapore cohort (>200 patients) was performed to derive mutational signatures of ARID1A inactivation across molecular subtypes. Single-cell transcriptomic profiles of ARID1A-mutated GCs were analysed to examine tumour microenvironmental changes arising from ARID1A loss. Genome-wide ARID1A binding and chromatin profiles (H3K27ac, H3K4me3, H3K4me1, ATAC-seq) were generated to identify gastric-specific epigenetic landscapes regulated by ARID1A. Distinct cancer hallmarks of ARID1A-mutated GCs were converged at the genomic, single-cell and epigenomic level, and targeted by pharmacological inhibition. RESULTS: We observed prevalent ARID1A inactivation across GC molecular subtypes, with distinct mutational signatures and linked to a NFKB-driven proinflammatory tumour microenvironment. ARID1A-depletion caused loss of H3K27ac activation signals at ARID1A-occupied distal enhancers, but unexpectedly gain of H3K27ac at ARID1A-occupied promoters in genes such as NFKB1 and NFKB2. Promoter activation in ARID1A-mutated GCs was associated with enhanced gene expression, increased BRD4 binding, and reduced HDAC1 and CTCF occupancy. Combined targeting of promoter activation and tumour inflammation via bromodomain and NFKB inhibitors confirmed therapeutic synergy specific to ARID1A-genomic status. CONCLUSION: Our results suggest a therapeutic strategy for ARID1A-mutated GCs targeting both tumour-intrinsic (BRD4-assocatiated promoter activation) and extrinsic (NFKB immunomodulation) cancer phenotypes.


Assuntos
Neoplasias Gástricas , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/terapia , Neoplasias Gástricas/patologia , Proteínas Nucleares/genética , Epigenômica , Mutação , Microambiente Tumoral/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ciclo Celular/genética
4.
J Med Virol ; 95(1): e28258, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36305052

RESUMO

Waning antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the emergence of variants of concern highlight the need for booster vaccinations. This is particularly important for the elderly population, who are at a higher risk of developing severe coronavirus disease 2019 (COVID-19) disease. While studies have shown increased antibody responses following booster vaccination, understanding the changes in T and B cell compartments induced by a third vaccine dose remains limited. We analyzed the humoral and cellular responses in subjects who received either a homologous messenger RNA(mRNA) booster vaccine (BNT162b2 + BNT162b2 + BNT162b2; ''BBB") or a heterologous mRNA booster vaccine (BNT162b2 + BNT162b2 + mRNA-1273; ''BBM") at Day 0 (prebooster), Day 7, and Day 28 (postbooster). Compared with BBB, elderly individuals (≥60 years old) who received the BBM vaccination regimen display higher levels of neutralizing antibodies against the Wuhan and Delta strains along with a higher boost in immunoglobulin G memory B cells, particularly against the Omicron variant. Circulating T helper type 1(Th1), Th2, Th17, and T follicular helper responses were also increased in elderly individuals given the BBM regimen. While mRNA vaccines increase antibody, T cell, and B cell responses against SARS-CoV-2 1 month after receiving the third dose booster, the efficacy of the booster vaccine strategies may vary depending on age group and regimen combination.


Assuntos
COVID-19 , SARS-CoV-2 , Idoso , Humanos , Pessoa de Meia-Idade , SARS-CoV-2/genética , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas de mRNA , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinação
5.
J Foot Ankle Surg ; 62(3): 505-510, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36690511

RESUMO

No previous studies have evaluated the intra- and interobserver reliability between the Weber, Lauge-Hansen and AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification systems under time constraints. This study compares the interobserver and intraobserver reliability of the aforementioned classification systems under simulated time constraints. Anteroposterior and lateral radiographs of ankle malleolar fractures from 80 consecutive patients from 2015 to 2016 were classified by 2 independent observers according to Weber, Lauge-Hansen and AO/OTA. Classifications were conducted over 4 successive weeks under timed (25-seconds) and untimed conditions, with 1-week gaps between each classification. Cohen's kappa and percentage agreement were calculated. Cohen's kappa for interobserver agreement ranged 0.67 to 0.67 and 0.59 to 0.73 for untimed and timed classifications for Weber; 0.38 to 0.47 and 0.44 to 0.50 for Lauge-Hansen; 0.28 to 0.49 and 0.13 to 0.37 for AO/OTA. Intraobserver agreement ranged from 0.83 to 0.85 and 0.78 to 0.79 for untimed and timed classifications for Weber; 0.46 to 0.65 and 0.59 to 0.73 for Lauge-Hansen; 0.42 to 0.63 and 0.40 to 0.51 for AO/OTA. Based on the Landis and Koch's benchmark scale, there was substantial agreement in the inter- and intraobserver variables for Weber; moderate agreement in inter- and intraobserver variables for Lauge-Hansen; fair and moderate agreement in inter- and intraobserver variables respectively for AO/OTA. Interobserver and intraobserver reliability was the most substantial for Weber, followed by Lauge-Hansen and AO/OTA. Time constraint did not have a statistically significant effect on the reliability of classifications. We recommend concurrent usage of the Weber and Lauge-Hansen system, since they demonstrate the greatest reliability and reproducibility, and confer better understanding of the fracture type, respectively.


Assuntos
Fraturas do Tornozelo , Humanos , Fraturas do Tornozelo/diagnóstico por imagem , Reprodutibilidade dos Testes , Variações Dependentes do Observador , Radiografia , Articulação do Tornozelo/diagnóstico por imagem
6.
World J Surg ; 46(11): 2778-2787, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35989371

RESUMO

BACKGROUND: An updated systematic review and meta-analysis was conducted to compare radiofrequency ablation (RFA) versus repeat hepatectomy (RH) for patients with recurrent hepatocellular carcinoma (rHCC) after a previous liver resection. METHODS: PubMed, EMBASE, and Cochrane databases were searched from inception to October 2021 for randomized controlled trials and propensity-score matched studies. Individual participant survival data of disease-free survival (DFS) and overall survival (OS) were extracted and reconstructed followed by one-stage and two-stage meta-analysis. Secondary outcomes were major complications and length of hospital stay (LOHS). RESULTS: A total of seven studies (1317 patients) were analysed. In both one-stage and two-stage meta-analysis, there was no significant difference in OS between the RFA and RH cohorts (Hazard Ratio (HR) 1.15, 95% CI 0.98-1.36, P = 0.094 and HR 1.12, 95% CI 0.77-1.64, P = 0.474 respectively), while the RFA group had a higher hazard rate of disease recurrence compared to the RH group (HR 1.30, 95% CI 1.13-1.50, P < 0.001 and HR 1.31, 95% CI 1.09-1.57, P = 0.013, respectively). RFA was associated with fewer major complications and shorter LOHS versus RH (Odds Ratio 0.34, 95% CI 0.15-0.76, P = 0.009 and Weighted Mean Difference - 4.78, 95% CI - 6.30 to - 3.26, P < 0.001, respectively). CONCLUSIONS: RH may be associated with superior DFS for rHCC, at the expense of higher morbidity rate and longer LOHS. However, OS is comparable between both modalities. As such, these techniques may be utilized as complementary strategies depending on individual patient and disease factors. Large-scale, randomized, prospective studies are required to corroborate these findings.


Assuntos
Carcinoma Hepatocelular , Ablação por Cateter , Neoplasias Hepáticas , Ablação por Radiofrequência , Ablação por Cateter/métodos , Hepatectomia/métodos , Humanos , Recidiva Local de Neoplasia/patologia , Ablação por Radiofrequência/métodos , Resultado do Tratamento
7.
Appl Opt ; 59(31): 9690-9697, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33175805

RESUMO

The ECO-BB (Sea Bird Scientific) is a popular instrument used by water optics researchers to measure the backscattering coefficient of waters in the visible to near-infrared wavelengths. The ECO-BB is calibrated by default for oceanic waters where the backscattering coefficient is typically low. In inland and coastal waters however, there is a tendency for the ECO-BB to reach saturation due to the high number of suspended particles. In the paper, a simple method is presented to extend the range of the ECO-BB instrument in such waters using a nephelometric turbidimeter. The method was first tested on powdered calcium carbonate in pure freshwater, followed by collected water samples from the Singapore Straits and the Lupar River in Sarawak. All three tests confirm the correlation between the ECO-BB and turbidimeter and show that the turbidimeter is a good proxy for backscattering coefficient measurements in turbid waters.

8.
Appl Opt ; 58(10): 2671-2677, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31045069

RESUMO

In ocean-color remote sensing, subsurface remote-sensing reflectance (r r s ) of optically deep waters can be linked to its absorption (a) and backscattering coefficients (b b ) by various models. The use of such models allows for quick calculations r r s from such coefficients, eliminating the need to solve the radiative transfer equation. In particular, r r s can be expressed as a function of bb/(a+bb). HydroLight and Monte Carlo simulations showed that commonly used models underestimate r r s in waters with high suspended sediment loads. Monte Carlo simulations confirmed that this issue is due to a sharp increase in multiple scattering events at high turbidity levels. A quartic polynomial model is derived relating r r s and inherent optical properties (IOPs) for waters of any turbidity, to avoid significant errors in waters of high turbidity.

10.
Neuroimage ; 128: 1-10, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26746580

RESUMO

Gratitude is a common aspect of social interaction, yet relatively little is known about the neural bases of gratitude expression, nor how gratitude expression may lead to longer-term effects on brain activity. To address these twin issues, we recruited subjects who coincidentally were entering psychotherapy for depression and/or anxiety. One group participated in a gratitude writing intervention, which required them to write letters expressing gratitude. The therapy-as-usual control group did not perform a writing intervention. After three months, subjects performed a "Pay It Forward" task in the fMRI scanner. In the task, subjects were repeatedly endowed with a monetary gift and then asked to pass it on to a charitable cause to the extent they felt grateful for the gift. Operationalizing gratitude as monetary gifts allowed us to engage the subjects and quantify the gratitude expression for subsequent analyses. We measured brain activity and found regions where activity correlated with self-reported gratitude experience during the task, even including related constructs such as guilt motivation and desire to help as statistical controls. These were mostly distinct from brain regions activated by empathy or theory of mind. Also, our between groups cross-sectional study found that a simple gratitude writing intervention was associated with significantly greater and lasting neural sensitivity to gratitude - subjects who participated in gratitude letter writing showed both behavioral increases in gratitude and significantly greater neural modulation by gratitude in the medial prefrontal cortex three months later.


Assuntos
Encéfalo/fisiologia , Emoções/fisiologia , Relações Interpessoais , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
11.
J Cachexia Sarcopenia Muscle ; 15(5): 1850-1857, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38925534

RESUMO

BACKGROUND: Accurate preoperative risk assessment for major colorectal cancer (CRC) surgery remains challenging. Body composition (BC) and cardiopulmonary exercise testing (CPET) can be used to evaluate risk. The relationship between BC and CPET in patients undergoing curative CRC surgery is unclear. METHODS: Consecutive patients undergoing CPET prior to CRC surgery between 2010 and 2020 were identified between two different UK hospitals. Body composition phenotypes such as sarcopenia, myosteatosis, and visceral obesity were defined using widely accepted thresholds using preoperative single axial slice CT image at L3 vertebrae. Relationships between clinicopathological, BC, and CPET variables were investigated using linear regression analysis. RESULTS: Two hundred eighteen patients with stage I-III CRC were included. The prevalence of sarcopenia, myosteatosis, and visceral obesity was 62%, 33%, and 64%, respectively. The median oxygen uptake at anaerobic threshold (VO2 at AT) was 12.2 mL/kg/min (IQR 10.6-14.2), and oxygen uptake at peak exercise (VO2 peak) was 18.8 mL/kg/min (IQR 15.4-23). On univariate linear regression analysis, male sex (P < 0.001) was positively associated with VO2 at AT. While ASA grade (P < 0.001) and BMI (P = 0.007) were negatively associated with VO2 at AT, on multivariate linear regression analysis, these variables remained significant (P < 0.05). On univariate linear regression analysis, male sex (P < 0.001) was positively associated with VO2 peak, whereas age (P < 0.001), ASA grade (P < 0.001), BMI (P = 0.003), sarcopenia (P = 0.015), and myosteatosis (P < 0.001) were negatively associated with VO2 peak. On multivariate linear regression analysis age (P < 0.001), ASA grade (P < 0.001), BMI (P < 0.001), and sarcopenia (P = 0.006) were independently and negatively associated with VO2 peak. CONCLUSIONS: The novel finding that sarcopenia is independently associated with reduced VO2 peak performance in CPET supports the supposition that reduced muscle mass relates to poor physical function in CRC patients. Further work should be undertaken to assess whether sarcopenia diagnosed on CT can act as suitable surrogate for CPET to further enhance personalized risk stratification.


Assuntos
Neoplasias Colorretais , Aptidão Física , Sarcopenia , Humanos , Sarcopenia/etiologia , Masculino , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/complicações , Feminino , Idoso , Pessoa de Meia-Idade , Composição Corporal
12.
bioRxiv ; 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38352618

RESUMO

Colibactin is a secondary metabolite produced by bacteria present in the human gut and is implicated in the progression of colorectal cancer and inflammatory bowel disease. This genotoxin alkylates deoxyadenosines on opposite strands of host cell DNA to produce DNA interstrand cross-links (ICLs) that block DNA replication. While cells have evolved multiple mechanisms to resolve ("unhook") ICLs encountered by the replication machinery, little is known about which of these pathways promote resistance to colibactin-induced ICLs. Here, we use Xenopus egg extracts to investigate replication-coupled repair of plasmids engineered to contain site-specific colibactin-ICLs. We show that replication fork stalling at a colibactin-ICL leads to replisome disassembly and activation of the Fanconi anemia ICL repair pathway, which unhooks the colibactin-ICL through nucleolytic incisions. These incisions generate a DNA double-strand break intermediate in one sister chromatid, which can be repaired by homologous recombination, and a monoadduct ("ICL remnant") in the other. Our data indicate that translesion synthesis past the colibactin-ICL remnant depends on Polη and a Polκ-REV1-Polζ polymerase complex. Although translesion synthesis past colibactin-induced DNA damage is frequently error-free, it can introduce T>N point mutations that partially recapitulate the mutation signature associated with colibactin exposure in vivo. Taken together, our work provides a biochemical framework for understanding how cells tolerate a naturally-occurring and clinically-relevant ICL.

13.
Commun Chem ; 7(1): 7, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38182798

RESUMO

Halogenation of pyrrole requires strong electrophilic reagents and often leads to undesired polyhalogenated products. Biocatalytic halogenation is a highly attractive approach given its chemoselectivity and benign reaction conditions. While there are several reports of enzymatic phenol and indole halogenation in organic synthesis, corresponding reports on enzymatic pyrrole halogenation have been lacking. Here we describe the in vitro functional and structural characterization of PrnC, a flavin-dependent halogenase that can act on free-standing pyrroles. Computational modeling and site mutagenesis studies identified three key residues in the catalytic pocket. A moderate resolution map using single-particle cryogenic electron microscopy reveals PrnC to be a dimer. This native PrnC can halogenate a library of structurally diverse pyrrolic heterocycles in a site-selective manner and be applied in the chemoenzymatic synthesis of a chlorinated analog of the agrochemical fungicide Fludioxonil.

14.
Int J Radiat Biol ; 100(3): 445-452, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38166555

RESUMO

PURPOSE: Evaluate the structural damage and the changes in the photosynthesis and transpiration rates of aquatic lirium leaves caused by ultrasound (US) irradiation in search of environmentally friendly methodologies for the control of this weed. MATERIALS AND METHODS: Aquatic lirium plants were extracted from Xochimilco water canals in Mexico City. A part of the group of plants was selected for irradiation, and the rest formed the control group. The irradiation plants group was exposed to US irradiation of 17 kHz frequency and 30 W × 4 output power for 2 h, at noon and 25 °C room temperature. The structural analysis was done with a MOTICAM 1 digital camera, 800 × 600 pixels, incorporated into the MOTIC PSM-1000 optical microscope and edited with Motic Images Plus 2.0 ML software. The total stomata density and the damaged stomata density were determined by dividing the numbers of total and damaged stomata by the visual field area (67,917 mm2), respectively. The leaves' photosynthesis and transpiration rates were measured using an LI-6400XT Portable Photosynthesis System. RESULTS: Significant damage was observed in the stomata and epidermal cells, finding that the average ratio between the damaged and total stomata densities as a function of time (days) showed an exponential increase described by a Box-Lucas equation with a saturation value near unity and a maximum rate of change of the density of damaged stomata on zero-day (immediately after irradiation), decreasing as the days go by. The transpiration rate showed a sudden increase during the first hour after irradiation, reaching a maximum of 36% of its value before irradiation. It then quickly fell during the next 6 days and more slowly until the 21st day, decreasing 79.9% of its value before irradiation. The photosynthetic rate showed similar behavior with a 37.7% maximum increment and a 73.6% minimum decrease of its value before irradiation. CONCLUSIONS: The results of structural stomata damage on the ultrasound-irradiated aquatic lirium leaves are consistent with an excessive ultrasound stimulation on stomata's mechanical operation by guard cells that produce the measured significant increase of the photosynthetic and transpiration rates during the first hour after irradiation. The initial high evaporation could alter the water potential gradient, with a possible generation of tensions in the xylem that could cause embolism in their conduits. The loss of xylem conductivity or hydraulic failure would be consistent with the observed significant fall in the photosynthesis and transpiration rates of the aquatic lirium leaves after its sudden rise in the first hour after irradiation.


Assuntos
Estômatos de Plantas , Transpiração Vegetal , Estômatos de Plantas/fisiologia , Transpiração Vegetal/fisiologia , Fotossíntese , Folhas de Planta , Água
15.
Food Sci Nutr ; 11(9): 5364-5378, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37701201

RESUMO

Coffea liberica, commonly known as Liberica coffee, is a kind of coffee that originated in Liberia, a West African country. It is considered a less-known coffee bean variety, which accounts for less than 2% of commercially produced coffee worldwide. In this study, the influences of optimization of microwave-assisted extraction (MAE) on the total phenolic content (TPC), total flavonoid content (TFC), and total carbohydrate content (TCC) of bioactive compounds extracted from Sarawak Liberica sp. coffee pulp were studied. Response surface methodology was adopted with a face-centered central composite design to generate 34 responses by taking three microwave parameters into consideration, microwave power (watt), time of irradiation (second), and solvent-to-feed ratio as independent variables. As a result, the findings revealed that optimum extraction conditions were conducted as follows: microwave power of 700 W, time of irradiation of 180 s, and solvent-to-feed ratio of 86.644:1. While under optimal extraction conditions, MAE outperformed conventional maceration extraction in terms of extraction efficiency and had no significant difference (p < .05) with Soxhlet extraction on the extraction of TPC (12.94 ± 2.25 mg GAE/g), TFC (9.84 ± 0.38 mg QE/g), and TCC (876.50 ± 64.15 mg GE/g). Present work advances the usage of Sarawak Liberica sp. coffee for the development of functional products and aids in reducing environmental pollution by utilization of coffee pulp waste.

16.
Arthrosc Sports Med Rehabil ; 5(5): 100775, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37583621

RESUMO

Purpose: This study aims to compare the outcomes of fixed-loop device (FLD) vs adjustable-loop device (ALD) graft fixation with up to 2-year follow-up in patients undergoing primary anterior cruciate ligament reconstruction (ACLR) in a predominantly Asian setting. Methods: Prospectively collected outcome measures as well as clinical records of patients who underwent primary ACLR using either FLD or ALD fixation of hamstring tendon autograft performed by a single surgeon were reviewed. The surgeon in this study used a fixed-loop device from 2018 to 2019 and then changed to adjustable loop from 2019 to 2020. Suspensory fixation was performed on the femoral side, and aperture (interference screw) fixation was performed on the tibial side. Outcome measures included knee range of motion, KT-1000 arthrometer testing, Lysholm knee score, and Tegner activity scale. Patients were assessed preoperatively and postoperatively at regular intervals of 6, 12, and 24 months. Results: A total of 105 patients were identified. Forty-six were excluded due to incomplete follow-up data, so 59 patients with full 2-year follow-up were included in the final study group. Both groups (FLD vs ALD) were similar in demographics except for age (P = .042). Out of 105, there were 59 patients remaining in the study group with 2-year follow-up data. No significant differences were observed between the 2 groups at all respective testing intervals. Conclusions: FLDs and ALDs for suspensory fixation of hamstring tendon autograft in ACLR had similar clinical outcomes with a minimum of 2-year follow up. There is no evidence of graft loosening from loop lengthening. Level of Evidence: Level III, retrospective comparative trial.

17.
J Pediatr Orthop B ; 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37669155

RESUMO

To investigate the efficacy of cryotherapy in relieving postoperative pain and restoring knee range-of-motion (ROM) after paediatric anterior cruciate ligament reconstruction (ACLR). Patients undergoing primary ACLR were randomised into cryotherapy or non-cryotherapy groups. Those receiving cryotherapy were subjected to a standardised icing protocol. Icing schedules were used to assess compliance. Standard postoperative rehabilitation protocol was followed for both groups. Outcome measurements were visual analogue scale at rest and movement and knee ROM. Patients were assessed on postoperative day 1 (POD1), 1, 4 and 6 weeks. Twenty-one out of 42 patients received cryotherapy. Both groups were similar in demographics, surgical technique and use of intraoperative anaesthesia. Patients in the cryotherapy group reported lower overall mean pain scores throughout the study duration at rest (0.61 ±â€…1.70, 95% CI = 0.23-0.99 vs. 1.06 ±â€…2.03, 95% CI = 0.60-1.53) and on movement (2.19 ±â€…2.68, 95% CI = 1.59-2.79 vs. 3.13 ±â€…2.75, 95% CI = 2.51-3.75; P = 0.032). Knee flexion in the cryotherapy group showed better recovery of knee flexion from week 4 onwards. Improvement of knee flexion from POD1 is statistically significant at week 6 (98.7 ±â€…19.1°, 95% CI = 89.5-107.9 vs. 65.4 ±â€…49.9°, 95% CI = 42.7-88.1; P = 0.010) and overall mean (71.2 ±â€…35.9°, 95% CI = 61.2-81.1 vs. 45.3 ±â€…55.5°, 95% CI = 30.4-60.2; P = 0.005). The cryotherapy group reported statistically significant better degree of overall mean knee extension (1.2 ±â€…3.3°, 95% CI = 0.5-2.0 vs. 2.6 ±â€…4.6°, 95% CI = 1.6-3.7; P = 0.032). The use of cryotherapy in postoperative ACLR recovery in paediatrics is a simple yet effective measure resulting in short-term pain relief and improvement in knee flexion.

18.
Biomolecules ; 13(7)2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37509117

RESUMO

RadH is one of the flavin-dependent halogenases that has previously exhibited promising catalytic activity towards hydroxycoumarin, hydroxyisoquinoline, and phenolic derivatives. Here, we evaluated new functional homologs of RadH and expanded its specificities for the halogenation of non-tryptophan-derived, heterocyclic scaffolds. Our investigation revealed that RadH could effectively halogenate hydroxyquinoline and hydroxybenzothiophene. Assay optimization studies revealed the need to balance the various co-factor concentrations and where a GDHi co-factor recycling system most significantly improves the conversion and efficiency of the reaction. A crystal structure of RadH was also obtained with a resolution of 2.4 Å, and docking studies were conducted to pinpoint the binding and catalytic sites for substrates.


Assuntos
Halogenação , Oxirredutases , Oxirredutases/metabolismo , Domínio Catalítico , Flavinas/química , Flavinas/metabolismo
19.
Singapore Med J ; 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37675681

RESUMO

Introduction: The most recent local study on the incidence of histological subtypes of all brain and spinal tumours treated surgically was published in 2000. In view of the outdated data, we investigated the presenting characteristics, histological subtypes and outcomes of adult patients who underwent surgery for brain or spinal tumours at our institution. Methods: A single-centre retrospective review of 501 patients who underwent surgery for brain or spinal tumours from 2016 to 2020 was conducted. The inclusion criteria were (a) patients who had a brain or spinal tumour that was histologically verified and (b) patients who were aged 18 years and above at the time of surgery. Results: Four hundred and thirty-five patients (86.8%) had brain tumours and 66 patients (13.2%) had spinal tumours. Patients with brain tumours frequently presented with cranial nerve palsy, headache and weakness, while patients with spinal tumours frequently presented with weakness, numbness and back pain. Overall, the most common histological types of brain and spinal tumours were metastases, meningiomas and tumours of the sellar region. The most common complications after surgery were cerebrospinal fluid leak, diabetes insipidus and urinary tract infection. In addition, 15.2% of the brain tumours and 13.6% of the spinal tumours recurred, while 25.7% of patients with brain tumours and 18.2% of patients with spinal tumours died. High-grade gliomas and metastases had the poorest survival and highest recurrence rates. Conclusion: This study serves as a comprehensive update of the epidemiology of brain and spinal tumours and could help guide further studies on brain and spinal tumours.

20.
Antiviral Res ; 220: 105739, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37944824

RESUMO

With approximately 3.8 billion people at risk of infection in tropical and sub-tropical regions, Dengue ranks among the top ten threats worldwide. Despite the potential for severe disease manifestation and the economic burden it places on endemic countries, there is a lack of approved antiviral agents to effectively treat the infection. Flavonoids, including baicalein, have garnered attention for their antimicrobial properties. In this study, we took a rational and iterative approach to develop a series of baicalein derivatives with improved antiviral activity against Dengue virus (DENV). Compound 11064 emerged as a promising lead candidate, exhibiting antiviral activity against the four DENV serotypes and representative strains of Zika virus (ZIKV) in vitro, with attractive selectivity indices. Mechanistic studies revealed that Compound 11064 did not prevent DENV attachment at the cell surface, nor viral RNA synthesis and viral protein translation. Instead, the drug was found to impair the post-receptor binding entry steps (endocytosis and/or uncoating), as well as the late stage of DENV infection cycle, including virus assembly/maturation and/or exocytosis. The inability to raise DENV resistant mutants, combined with significant antiviral activity against an unrelated RNA virus (Enterovirus-A71) suggested that Compound 11064 targets the host rather than a viral protein, further supporting its broad-spectrum antiviral potential. Overall, Compound 11064 represents a promising antiviral candidate for the treatment of Dengue and Zika.


Assuntos
Vírus da Dengue , Dengue , Flavivirus , Infecção por Zika virus , Zika virus , Humanos , Infecção por Zika virus/tratamento farmacológico , Antivirais/uso terapêutico , Dengue/tratamento farmacológico
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