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1.
BMC Musculoskelet Disord ; 25(1): 506, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943135

RESUMO

BACKGROUND: Functional assessments are crucial to evaluate treatment outcomes in clinical and animal studies on rotator cuff injuries. While gait analysis is commonly used to assess animal models of rotator cuff tears, it is less relevant for human patients as the human shoulder is typically assessed in a non-weight-bearing condition. The present study introduces the skilled reaching test as a shoulder functional assessment tool for rats, which allows for evaluation without weight bearing. METHODS: In the control group, 8 male Sprague-Dawley rats received rotator cuff tear surgery without repair. In the rotator cuff repair group, 20 rats received rotator cuff repair at 4 weeks post rotator cuff tear. For the skilled reaching test, rats were trained to extend their forelimbs to fetch food pellets, and the number of trials, number of attempts and the success rate were recorded. The gait analysis and skilled reaching test were performed at baseline, 4 weeks post-tear, 1, 2, 4, and 8 weeks post-repair. The repeated measures analysis of variance was used to evaluate the effects of time on the shoulder function. The significance level was set at 0.05. RESULTS: The skilled reaching test required 216 h to conduct, while the gait analysis took 44 h. In the rotator cuff repair group, gait performance significantly deteriorated at 1 week post-repair and restored to 4 weeks post-tear levels at 4 weeks post-repair. Regarding the skilled reaching test, the number of attempts, number of trials and the success rate decreased at 1 week post-repair. Subsequently, there was a brief rebound in performance observed at 2 weeks post-repair, followed by a continued decline in the number of attempts and trials. By 8 weeks post-repair, only the success rate had restored to levels similar to those observed at 4 weeks post-tear. CONCLUSION: The skilled reaching test can detect functional deficiencies following rotator cuff tear and repair, while it requires high time and labour costs.


Assuntos
Modelos Animais de Doenças , Ratos Sprague-Dawley , Lesões do Manguito Rotador , Animais , Lesões do Manguito Rotador/cirurgia , Lesões do Manguito Rotador/fisiopatologia , Lesões do Manguito Rotador/diagnóstico , Projetos Piloto , Masculino , Ratos , Análise da Marcha/métodos , Manguito Rotador/cirurgia , Manguito Rotador/fisiopatologia , Marcha/fisiologia , Recuperação de Função Fisiológica
2.
Opt Express ; 31(11): 17547-17556, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37381485

RESUMO

Terahertz (THz) filters with high transmission coefficient (T) in the passband and frequency selectivity are critical in numerous applications such as astronomical detection and next-generation wireless communication. Freestanding bandpass filters eliminate the Fabry-Pérot effect of substrate, thus providing a promising choice for cascaded THz metasurfaces. However, the freestanding bandpass filters (BPFs) using the traditional fabrication process are costly and fragile. Here, we demonstrate a methodology to fabricate THz BPFs using aluminum (Al) foils. We designed a series of filters with center frequencies below 2 THz and manufacture them on 2-inch Al foils with various thicknesses. By optimizing the geometry, T of the filter at the center frequency is over 92%, and the relative full-width half maxima (FWHM) is as narrow as 9%. The responses of BPFs show that "cross-shaped" structures are insensitive to the polarization direction. The simple and low-cost fabrication process of the freestanding BPFs promise their widespread applications in THz systems.

3.
Inorg Chem ; 62(39): 16038-16046, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37721422

RESUMO

As the demand for fuel continues to increase, the development of energy devices with excellent performance is crucial. Supercapacitors (SCs) are attracting attention for their advantages of high specific energy and a long cycle life. At present, the development of high-performance electrode materials is the main point for research and development of SCs. Transition metal sulfides have the advantages of a large interlayer space and high theoretical capacity, making them promising electrode materials. Herein, we reported a series of ultrathin mesoporous iron family element (Fe, Co, Ni) molybdenum disulfide (MxMo1-xS2/C, M = Fe, Co, and Ni) by a template method. The original monolayer mesoporous structure of MoS2/C was maintained, and accumulation and agglomeration of MoS2/C were avoided. Based on our investigations, the best performance was that of CoxMo1-xS2/C nanohybrids. Furthermore, the concentrations of Co and Mo ions were modulated to obtain the best performance, in which Mo and Co ions were released at 1:1, 1:2, and 1:3 ratios and they were named CoxMo1-xS2/C-1, CoxMo1-xS2/C-2, and CoxMo1-xS2/C-3, respectively. Overall, these materials represent a significant improvement and show promise as high-performance SC electrode materials due to their enhanced capacitance and stability. At a current density of 0.5 A g-1, CoxMo1-xS2/C-2 has the optimal specific capacitance of 184 F g-1. CoxMo1-xS2/C-2 as an SC electrode exhibited better reversible capacity and cycling stability than MoS2/C, which is an improvement over MoS2/C regarding reversible capacity and cycling stability.

4.
Int J Mol Sci ; 23(7)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35408931

RESUMO

Both acute and chronic tendon injuries are disabling sports medicine problems with no effective treatment at present. Sustained oxidative stress has been suggested as the major factor contributing to fibrosis and adhesion after acute tendon injury as well as pathological changes of degenerative tendinopathy. Numerous in vitro and in vivo studies have shown that the inhibition of oxidative stress can promote the tenogenic differentiation of tendon stem/progenitor cells, reduce tissue fibrosis and augment tendon repair. This review aims to systematically review the literature and summarize the clinical and pre-clinical evidence about the potential relationship of oxidative stress and tendon disorders. The literature in PubMed was searched using appropriate keywords. A total of 81 original pre-clinical and clinical articles directly related to the effects of oxidative stress and the activators or inhibitors of oxidative stress on the tendon were reviewed and included in this review article. The potential sources and mechanisms of oxidative stress in these debilitating tendon disorders is summarized. The anti-oxidative therapies that have been examined in the clinical and pre-clinical settings to reduce tendon fibrosis and adhesion or promote healing in tendinopathy are reviewed. The future research direction is also discussed.


Assuntos
Tendinopatia , Traumatismos dos Tendões , Fibrose , Humanos , Estresse Oxidativo , Tendinopatia/tratamento farmacológico , Tendinopatia/patologia , Traumatismos dos Tendões/patologia , Tendões
5.
Matern Child Nutr ; 18(1): e13289, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34816596

RESUMO

In China, the prevalence of undernutrition among children under 5 years of age has declined significantly during recent decades. However, noticeable gaps exist between rural and urban areas. Since 2012, a government-funded nutrition programme, Ying Yang Bao (YYB; soybean powder-based iron-rich supplement) programme, has been implemented in poor rural areas to decrease the risk of developing anaemia among children aged 6-23 months, but there are still inadequate health care awareness, feeding knowledge and skills among caregivers. From June 2018 to December 2020, a child health counselling intervention was delivered through a home visit based on the YYB programme in Liangshan. Child health messages were given by trained village child health assistants while distributing YYB. Surveys were conducted before and after the intervention to analyse changes in child health check-up frequency, complementary feeding practice and prevalence of undernutrition. After the intervention, the proportion of children who had regular health check-ups, who were vaccinated and who met the minimum YYB consumption significantly increased from 26.0%, 81.6%, and 67.8% to 59.7%, 95.0%, and 79.2%. Increased rates of IYCF indicators (introduction of solid, semisolid, or soft foods, minimum dietary diversity and consumption of iron-rich or iron-fortified foods) were observed after the intervention. The prevalence of stunting, underweight, wasting, and anaemia significantly decreased from 26.3% to 10.8%, 13.4% to 8.7%, 14.0% to 10.5%, and 52.1% to 43.9%. This intervention can be well integrated into the YYB programme with less additional resources. Children in resource-limited areas will benefit more from a comprehensive nutritional package, including food supplements and child health education.


Assuntos
Serviços de Saúde da Criança , Saúde da Criança , Aconselhamento , Fenômenos Fisiológicos da Nutrição do Lactente , Desnutrição , Aceitação pelo Paciente de Cuidados de Saúde , Saúde da Criança/estatística & dados numéricos , Serviços de Saúde da Criança/estatística & dados numéricos , China/epidemiologia , Serviços de Saúde Comunitária/estatística & dados numéricos , Aconselhamento/estatística & dados numéricos , Métodos de Alimentação/estatística & dados numéricos , Humanos , Lactente , Desnutrição/complicações , Desnutrição/epidemiologia , Desnutrição/terapia , Estado Nutricional , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , População Rural
6.
Mol Cell ; 43(6): 940-9, 2011 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-21925382

RESUMO

In Escherichia coli, RNA degradation often begins with conversion of the 5'-terminal triphosphate to a monophosphate, creating a better substrate for internal cleavage by RNase E. Remarkably, no homolog of this key endonuclease is present in many bacterial species, such as Bacillus subtilis and various pathogens. Here, we report that the degradation of primary transcripts in B. subtilis can nevertheless be triggered by an analogous process to generate a short-lived, monophosphorylated intermediate. Like its E. coli counterpart, the B. subtilis RNA pyrophosphohydrolase that catalyzes this event is a Nudix protein that prefers unpaired 5' ends. However, in B. subtilis, this modification exposes transcripts to rapid 5' exonucleolytic degradation by RNase J, which is absent in E. coli but present in most bacteria lacking RNase E. This pathway, which closely resembles the mechanism by which deadenylated mRNA is degraded in eukaryotic cells, explains the stabilizing influence of 5'-terminal stem-loops in such bacteria.


Assuntos
Bacillus subtilis/genética , Estabilidade de RNA , RNA Bacteriano/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/fisiologia , Fosforilação , Pirofosfatases/genética , Pirofosfatases/fisiologia , Ribonucleases/metabolismo , Ribonucleases/fisiologia , Nudix Hidrolases
7.
Artigo em Inglês | MEDLINE | ID: mdl-38194386

RESUMO

As an effective alternative to deep neural networks, broad learning system (BLS) has attracted more attention due to its efficient and outstanding performance and shorter training process in classification and regression tasks. Nevertheless, the performance of BLS will not continue to increase, but even decrease, as the number of nodes reaches the saturation point and continues to increase. In addition, the previous research on neural networks usually ignored the reason for the good generalization of neural networks. To solve these problems, this article first proposes the Extreme Fuzzy BLS (E-FBLS), a novel cascaded fuzzy BLS, in which multiple fuzzy BLS blocks are grouped or cascaded together. Moreover, the original data is input to each FBLS block rather than the previous blocks. In addition, we use residual learning to illustrate the effectiveness of E-FBLS. From the frequency domain perspective, we also discover the existence of the frequency principle in E-FBLS, which can provide good interpretability for the generalization of the neural network. Experimental results on classical classification and regression datasets show that the accuracy of the proposed E-FBLS is superior to traditional BLS in handling classification and regression tasks. The accuracy improves when the number of blocks increases to some extent. Moreover, we verify the frequency principle of E-FBLS that E-FBLS can obtain the low-frequency components quickly, while the high-frequency components are gradually adjusted as the number of FBLS blocks increases.

8.
Clin Exp Med ; 24(1): 195, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39167309

RESUMO

OBJECTIVES: There is currently no evidence documenting the clinical characteristics and prognosis of non-high-risk patients with incidental stage T1 lung cancer (LC). The aim of this study was to investigate the clinical characteristics and prognosis of non-high-risk patients with incidental stage T1 LC. METHODS: This prospective cohort study included patients with incidental stage T1 LC who were diagnosed pathologically at the First Affiliated Hospital of Chongqing Medical University between 1st Jan 2019 and 31st Dec 2023. The follow-up time for all participants concluded on 31st Jan 2024, or upon death. All included patients were divided into non-high-risk (observation) and high-risk (control) groups based on the 2021 US preventative services task force recommendations. The primary outcomes were overall survival probability and LC-specific survival probability. The secondary outcomes were clinical characteristics, including demographic variables, histological types and TNM staging. RESULTS: We studied 1876 patients with incidental stage T1 LC. Of these, 1491 (79.48%) non-high-risk patients were included in the observation group, and the remaining 385 (20.52%) high-risk patients composed the control group. The follow-up interval was between 0 and 248 months for all participants, with a median time of 41.64 ± 23.85 months. The patients in the observation group were younger and had smaller tumors, more adenocarcinomas, and earlier disease stages than those in the control group (p ≤ 0.001). The overall survival probability (HR = 0.23, [95% CI: 0.18, 0.31], p < 0.001) and the LC-specific survival probability (HR = 0.23, [95% CI: 0.17, 0.31], p < 0.001) for the patients in the observation group were also both higher than those in the control group. The results appeared to be consistent across important subgroups. CONCLUSION: In this study, non-high-risk patients with incidental stage T1 LC were younger, had smaller tumors, had more adenocarcinomas, had a lower probability of metastasis, and had longer survival than did high-risk patients.


Assuntos
Neoplasias Pulmonares , Estadiamento de Neoplasias , Humanos , Masculino , Feminino , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/mortalidade , Estudos Prospectivos , Pessoa de Meia-Idade , Idoso , Prognóstico , Achados Incidentais , Análise de Sobrevida , Adulto , Idoso de 80 Anos ou mais , Fatores de Risco
9.
ACS Appl Mater Interfaces ; 16(35): 46145-46158, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39180482

RESUMO

After rotator cuff injuries, uncontrolled inflammation hinders tendon-bone junction regeneration and induces scar formation in situ. Therefore, precisely controlling inflammation could be a solution to accelerate tendon-bone junction regeneration. In this study, we synthesized a peptide-metal ion complex hydrogel with thermosensitive capability that can be used as a hydrogel chemical regulator. By the coordination complex between Mg2+ and BMP-12, the free and coordinated Mg2+ can be programmability released from the hydrogel. The fast release of free Mg2+ can prevent inflammation at the early stage of injuries, according to the results of RT-qPCR and immunofluorescence staining. Then, the coordinated Mg2+ was slowly released from the hydrogel and provided an anti-inflammatory environment for tendon-bone junction regeneration in the long term. Finally, the hydrogel demonstrated enhanced therapeutic effects in a rat rotator cuff tear model. Overall, the Mg2+/BMP-12 peptide-metal ion complex-based hydrogel effectively addresses the regenerative requirements of the tendon-bone junction across various stages by graded modulating inflammation.


Assuntos
Hidrogéis , Inflamação , Peptídeos , Ratos Sprague-Dawley , Tendões , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Ratos , Peptídeos/química , Peptídeos/farmacologia , Inflamação/tratamento farmacológico , Inflamação/patologia , Tendões/efeitos dos fármacos , Tendões/patologia , Magnésio/química , Magnésio/farmacologia , Regeneração/efeitos dos fármacos , Lesões do Manguito Rotador/tratamento farmacológico , Lesões do Manguito Rotador/patologia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/patologia , Masculino , Regeneração Óssea/efeitos dos fármacos
10.
Am J Sports Med ; 51(1): 66-80, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36592017

RESUMO

BACKGROUND: Stem cell sheets provide a scaffold-free option for the promotion of graft healing after anterior cruciate ligament reconstruction (ACLR). However, cell viability, stability, and potential uncontrolled actions create challenges for clinical translation. The decellularization of cell sheets may overcome these problems as studies have shown that the natural extracellular matrix of stem cells is bioactive and can promote tissue repair. HYPOTHESIS: The decellularized tendon-derived stem cell (dTDSC) sheet can promote graft healing after ACLR. STUDY DESIGN: Controlled laboratory study. METHODS: An optimized decellularization protocol was developed to decellularize the TDSC sheets. A total of 64 Sprague-Dawley rats underwent ACLR with or without the dTDSC sheet wrapping the tendon graft (n = 32/group). At 2 and 6 weeks after surgery, graft healing was assessed by micro-computed tomography, histology, and biomechanical testing. The accumulation of iNOS+ and CD206+ cells and the expression of metalloproteinase 1 (MMP-1), MMP-13, and tissue inhibitor of metalloprotease 1 (TIMP-1) were assessed by immunohistochemistry. RESULTS: The decellularization was successful, with the removal of 98.4% nucleic acid while preserving the collagenous proteins and bioactive factors. The expression of bone morphogenetic protein 2 (BMP-2) and VEGF in the dTDSC sheet was comparable with the TDSC sheet (P > .05). Micro-computed tomography showed significantly more tunnel bone formation in the dTDSC sheet group. The dTDSC sheet group demonstrated better graft osteointegration and higher integrity of graft midsubstance with significantly higher ultimate failure load (16.58 ± 7.24 vs 8.93 ± 2.45 N; P = .002) and stiffness (11.97 ± 5.21 vs 6.73 ± 2.20 N/mm; P = .027). Significantly fewer iNOS+ cells but more CD206+ cells, as well as lower MMP-1 and MMP-13 but higher TIMP-1 expression, were detected at the tendon-bone interface and graft midsubstance in the dTDSC sheet group. CONCLUSION: An optimized decellularization protocol for producing bioactive dTDSC sheets was developed. Wrapping tendon graft with a dTDSC sheet promoted graft healing after ACLR, likely via enhancing bone formation and angiogenesis by BMP-2 and VEGF, modulating macrophage polarization and MMP/TIMP expression, and physically protecting the tendon graft. CLINICAL RELEVANCE: dTDSC sheets alleviate the quality control and safety concerns of cell transplantation and can be used as a cell-free alternative for the promotion of graft healing in ACLR.


Assuntos
Reconstrução do Ligamento Cruzado Anterior , Ligamento Cruzado Anterior , Ratos , Animais , Ligamento Cruzado Anterior/cirurgia , Metaloproteinase 13 da Matriz , Ratos Sprague-Dawley , Microtomografia por Raio-X , Metaloproteinase 1 da Matriz , Inibidor Tecidual de Metaloproteinase-1 , Fator A de Crescimento do Endotélio Vascular , Tendões/cirurgia , Células-Tronco , Reconstrução do Ligamento Cruzado Anterior/métodos
11.
Am J Sports Med ; 51(2): 461-475, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36645043

RESUMO

BACKGROUND: Doxycycline (Doxy) has been shown to facilitate tendon healing by reducing on-site matrix metalloproteinase (MMP) activity, but its effect on graft healing after anterior cruciate ligament reconstruction (ACLR) has not been investigated, and the therapeutic effect of Doxy in preventing ACLR-induced posttraumatic osteoarthritis (PTOA) is unclear. HYPOTHESIS: Doxy promotes graft healing and alleviates the progression of PTOA after ACLR. STUDY DESIGN: Controlled laboratory study. METHODS: Sprague Dawley rats (n = 74; age, 12-13 weeks; male) that underwent ACLR were divided into untreated control and Doxy treatment (50 mg/kg/d orally until sacrifice) groups. At 2 and 6 weeks after surgery, graft healing was assessed by biomechanical testing, histology, immunohistochemical staining, and micro-computed tomography (µCT). The progression of PTOA was evaluated at 6 weeks by histology, the Mankin score, and immunofluorescence staining of the tibial plateau, and osteophyte formation was evaluated by µCT. Hindlimb weight distribution was evaluated at 6 weeks, and gait patterns were evaluated at 2 and 6 weeks. Intra-articular MMP activity was evaluated at 6 weeks in vivo using an MMP-activatable near-infrared fluorescent probe. RESULTS: Graft healing was enhanced by Doxy treatment, and the ultimate failure load (P = .002) and stiffness of the graft (P = .007) were significantly higher in the Doxy group at week 2. Bone mineral density and bone volume/total volume for both the tibial and the femoral tunnels at week 6 in the Doxy group were significantly higher compared with in the control group (P < .05). The overall graft healing scores were significantly higher in the Doxy group. Doxy treatment enhanced graft integration, intratunnel graft integrity, and collagen birefringence; more collagen types 1 and 10 and less MMP-13 were found at the graft-bone interface. At week 6, the Doxy group had a lower modified Mankin score (P = .033) and showed fewer MMP 13-positive chondrocytes at the articular cartilage surface (P = .002), indicating moderate joint cartilage damage. µCT revealed less osteophyte formation, and gait analysis revealed more symmetric weightbearing and gait patterns, after Doxy treatment at week 6 (P < .05). In vivo imaging with the near-infrared fluorescent probe identified significantly lower intra-articular MMP activity in the Doxy group at week 6 (P = .016). CONCLUSION: The oral administration of Doxy was able to synchronously promote graft healing and attenuate PTOA in an ACLR rat model. CLINICAL RELEVANCE: Our results indicated that Doxy, a widely used drug, is potentially beneficial to patients after ACLR.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Osteoartrite , Osteófito , Ratos , Masculino , Animais , Doxiciclina , Ratos Sprague-Dawley , Microtomografia por Raio-X , Corantes Fluorescentes , Osteoartrite/cirurgia , Colágeno , Reconstrução do Ligamento Cruzado Anterior/métodos , Lesões do Ligamento Cruzado Anterior/cirurgia
12.
J Tissue Eng Regen Med ; 16(8): 757-770, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35670621

RESUMO

Current rat model of rotator cuff (RC) tear could not mimic the suture anchor (SA) repair technique in the clinical practice. We designed a novel SA for RC repair of rats to establish a clinically relevant animal model. Small suture anchors that fit the rat shoulder were assembled. 60 rats were assigned to the transosseous (TO) repair group or SA repair group (n = 30/group). Micro-computed tomography (Micro-CT) scanning, biomechanical test and histological analysis were implemented at 2, 4, and 8-week post-repair. The failure load and stiffness in the SA group were significantly higher than those of TO group at 4-week post-repair. Micro-computed tomography analysis showed the bone mineral density and trabecular thickness of the SA group were significantly lower than those of TO group. The SA group showed a better insertion continuity at 4-week post-repair compared to TO group. No significant difference in gait parameters was found between groups. Therefore, SA repair is applicable for the rat model of RC tears. The SA repair achieved superior RC tendon healing, but more extensive initial bone damage compared to TO repair, while the shoulder function was comparable. This model could replicate the current repair technique in the clinical situation and be considered for future preclinical studies on healing enhancement for RC tears. Statement of Clinical Significance: With high clinical relevance, this model may facilitate the translation from an animal study into clinical trials.


Assuntos
Lesões do Manguito Rotador , Animais , Fenômenos Biomecânicos , Ratos , Manguito Rotador/diagnóstico por imagem , Manguito Rotador/patologia , Manguito Rotador/cirurgia , Lesões do Manguito Rotador/diagnóstico por imagem , Lesões do Manguito Rotador/patologia , Lesões do Manguito Rotador/cirurgia , Ombro/cirurgia , Âncoras de Sutura , Microtomografia por Raio-X
14.
RNA ; 15(12): 2331-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19850915

RESUMO

RNase J1, a ribonuclease with 5' exonuclease and endonuclease activities, is an important factor in Bacillus subtilis mRNA decay. A model for RNase J1 endonuclease activity in mRNA turnover has RNase J1 binding to the 5' end and tracking to a target site downstream, where it makes a decay-initiating cleavage. The upstream fragment from this cleavage is degraded by 3' exonucleases; the downstream fragment is degraded by RNase J1 5' exonuclease activity. Previously, DeltaermC mRNA was used to show 5'-end dependence of mRNA turnover. Here we used DeltaermC mRNA to probe RNase J1-dependent degradation, and the results were consistent with aspects of the model. DeltaermC mRNA showed increased stability in a mutant strain that contained a reduced level of RNase J1. In agreement with the tracking concept, insertion of a strong stem-loop structure at +65 resulted in increased stability. Weakening this stem-loop structure resulted in reversion to wild-type stability. RNA fragments containing the 3' end were detected in a strain with reduced RNase J1 expression, but were undetectable in the wild type. The 5' ends of these fragments mapped to the upstream side of predicted stem-loop structures, consistent with an impediment to RNase J1 5' exonuclease processivity. A DeltaermC mRNA deletion analysis suggested that decay-initiating endonuclease cleavage could occur at several sites near the 3' end. However, even in the absence of these sites, stability was further increased in a strain with reduced RNase J1, suggesting alternate pathways for decay that could include exonucleolytic decay from the 5' end.


Assuntos
Bacillus subtilis/enzimologia , Metiltransferases/genética , Estabilidade de RNA , RNA Mensageiro/metabolismo , Ribonucleases/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Deleção de Genes , Metiltransferases/química , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA Mensageiro/química , Ribossomos/metabolismo
15.
Artigo em Inglês | MEDLINE | ID: mdl-34094881

RESUMO

Anterior cruciate ligament reconstruction (ACLR) is a commonly performed procedure in Orthopaedic sports medicine. With advances in surgical techniques providing better positioning and fixation of the graft, subsequent graft failure to certain extent should be accounted by poor graft healing. Although different biological modulations for enhancement of graft healing have been tried in different clinical and animal studies, complete graft incorporation into bone tunnels and the "ligamentization" of the intra-articular part have not been fully achieved yet. Based on the understanding of graft healing process and its failure mechanism, the purpose of this review is to combine both the known basic science & clinical evidence, to provide a much clearer picture of the obstacle encountered in graft healing, so as to facilitate researchers on subsequent work on the enhancement of ACL graft healing.

16.
Front Bioeng Biotechnol ; 9: 756930, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35004636

RESUMO

Anterior cruciate ligament (ACL) tear is common in sports and accidents, and accounts for over 50% of all knee injuries. ACL reconstruction (ACLR) is commonly indicated to restore the knee stability, prevent anterior-posterior translation, and reduce the risk of developing post-traumatic osteoarthritis. However, the outcome of biological graft healing is not satisfactory with graft failure after ACLR. Tendon graft-to-bone tunnel healing and graft mid-substance remodeling are two key challenges of biological graft healing after ACLR. Mounting evidence supports excessive inflammation due to ACL injury and ACLR, and tendon graft-to-bone tunnel motion negatively influences these two key processes. To tackle the problem of biological graft healing, we believe that an inductive approach should be adopted, starting from the endpoint that we expected after ACLR, even though the results may not be achievable at present, followed by developing clinically practical strategies to achieve this ultimate goal. We believe that mineralization of tunnel graft and ligamentization of graft mid-substance to restore the ultrastructure and anatomy of the original ACL are the ultimate targets of ACLR. Hence, strategies that are osteoinductive, angiogenic, or anti-inflammatory should drive graft healing toward the targets. This paper reviews pre-clinical and clinical literature supporting this claim and the role of inflammation in negatively influencing graft healing. The practical considerations when developing a biological therapy to promote ACLR for future clinical translation are also discussed.

17.
Int J Biol Macromol ; 172: 19-29, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33444651

RESUMO

The treatment and repair of large bone defects remains a major therapeutic challenge in the clinical setting. Nanofiber scaffolds fabricated via the electrospinning technique have been developed as a universal method for bone regeneration due to their suitable properties. However, traditional two-dimensional (2D) nanofiber mats are usually too dense, which may prevent cell infiltration and growth, thereby restricting their application. Herein, a three-dimensional (3D) polycaprolactone nanofiber scaffold was developed, modified by biomineralization and silk fibroin coating. The scaffold possessed a parallel array of nanofiber surfaces, mimicking the parallel structure of fibrils in natural bone tissue. Furthermore, the fabricated radially or laterally interconnected macrochannels were investigated to elucidate the effect of the scaffold structure on bone regeneration. In vitro studies revealed that the scaffolds could guide cell arrangement and that the radially aligned scaffold demonstrated a stronger ability to promote cell proliferation. In vivo results showed that the radially aligned scaffold could guide tissue arrangement and remodeling and support a significantly faster regeneration rate of bone tissue. Therefore, 3D-mineralized polycaprolactone nanofiber scaffolds with radially interconnected macrochannels and aligned nanofibers are expected to be used in tissue engineering, including in the repair of bone defects, cartilage or other composite tissues.


Assuntos
Biomineralização/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Fibroínas/química , Nanofibras/química , Poliésteres/química , Alicerces Teciduais/química , Animais , Calcificação Fisiológica/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Engenharia Tecidual/métodos
18.
J Bacteriol ; 192(13): 3279-86, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20418391

RESUMO

rpsO mRNA, a small monocistronic mRNA that encodes ribosomal protein S15, was used to study aspects of mRNA decay initiation in Bacillus subtilis. Decay of rpsO mRNA in a panel of 3'-to-5' exoribonuclease mutants was analyzed using a 5'-proximal oligonucleotide probe and a series of oligonucleotide probes that were complementary to overlapping sequences starting at the 3' end. The results provided strong evidence that endonuclease cleavage in the body of the message, rather than degradation from the native 3' end, is the rate-determining step for mRNA decay. Subsequent to endonuclease cleavage, the upstream products were degraded by polynucleotide phosphorylase (PNPase), and the downstream products were degraded by the 5' exonuclease activity of RNase J1. The rpsO mRNA half-life was unchanged in a strain that had decreased RNase J1 activity and no RNase J2 activity, but it was 2.3-fold higher in a strain with decreased activity of RNase Y, a recently discovered RNase of B. subtilis encoded by the ymdA gene. Accumulation of full-length rpsO mRNA and its decay intermediates was analyzed using a construct in which the rpsO transcription unit was under control of a bacitracin-inducible promoter. The results were consistent with RNase Y-mediated initiation of decay. This is the first report of a specific mRNA whose stability is determined by RNase Y.


Assuntos
Bacillus subtilis/genética , Proteínas de Bactérias/metabolismo , Endorribonucleases/metabolismo , RNA Mensageiro/genética , Northern Blotting , Modelos Biológicos , Estabilidade de RNA/genética
19.
Pain Med ; 11(1): 127-32, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20447296

RESUMO

OBJECTIVE: We report a case of central pain successfully treated by epidural placement of spinal cord stimulator electrodes. Neuromodulation of primary afferent fibers and the underlying dorsal root entry zone provided effective analgesia whereas traditional lead placement over the dorsal columns on a prior occasion had not been effective. The rationale for this technique based on current understanding of the mechanisms of central pain and the risk/benefit considerations are discussed. CASE REPORT: A 52-year-old woman presented with a 2-year history of pain in the lateral hand secondary to a demyelinating episode in the C2-4 spinal cord secondary to multiple sclerosis. Medications, sympathetic blocks, and acupuncture had been ineffective. One year after an unsuccessful single-lead trial of spinal cord stimulation over the cervical dorsal columns, a dual-lead trial of spinal cord stimulation over the lateral cervical spinal cord and dorsal roots provided significant analgesia, prompting a successful permanent implant. OUTCOME MEASURES: Responses on the Brief Pain Inventory short form and quantitative thermosensory testing data were collected at two timepoints 16 days apart under two conditions: no stimulation and single-lead stimulation of cervical primary afferents and underlying spinal cord. RESULTS: The patient's questionnaire responses indicated significantly improved pain scores with lateral-lead neuromodulation that was associated with a reduction in her baseline heat hypoalgesia. CONCLUSIONS: Lateral-lead spinal cord stimulation may be effective for some central pain syndromes through a partial restoration of homeostatic small-fiber signaling. Neuroanatomical and physiological data in a larger population of patients will be required to predict the best responders to this therapeutic modality.


Assuntos
Terapia por Estimulação Elétrica , Espaço Epidural , Esclerose Múltipla/complicações , Dor/tratamento farmacológico , Dor/etiologia , Raízes Nervosas Espinhais , Doenças Desmielinizantes/patologia , Terapia por Estimulação Elétrica/efeitos adversos , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Esclerose Múltipla/patologia , Medição da Dor , Medula Espinal/patologia
20.
China CDC Wkly ; 2(45): 873-877, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-34594783

RESUMO

What is already known about this topic? Symptoms of malnutrition including anemia, stunting, wasting, and being underweight among children remained one of the major public health problems in poorer areas in China. More research is needed to guide interventions to improve nutrition and health among children in low-income regions. What is added by this report? The prevalences of anemia, stunting, wasting, and being underweight were 51.9%, 25.6%, 14.6%, and 9.5%, respectively, among children aged 6 to 24 months in the poorest areas of Liangshan. Associated factors were gender, age, education level and occupation of mother, breastfeeding, and caregiver knowledge. What are the implications for public health practice? Improving caregiver knowledge of nutrition and child feeding practices is crucial to address malnutrition among children. These findings can help more precisely understand the child health needs in poorer areas in order to develop effective interventions. They also provide evidence-based information to formulate child health promotion strategies in other countries with similar situations.

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