RESUMEN
BACKGROUND: Multivessel disease(MVD) is linked to a poorer prognosis, increased complications, longer hospital stays, and higher in-hospital mortality when compared to single-vessel disease(SVD).The purpose of this study is to explore the clinically relevant predictors of acute cornary syndrome (ACS) combined with MVD. METHODS: This multicenter retrospective study included 68,378 ACS patients from 240 hospitals.The clinical data were retrospectively analyzed with univariate and multivariate analyses to identify the predictive factors for MVD. RESULTS: When compared to SVD group, the MVD group showed a higher incidence of Major Adverse Cardiovascular Events(MACCEs), including all-cause death, myocardial infarction, stent thrombosis, and ischemic stroke during hospitalization, These differences were found to be statistically significant (P < 0.05) .The multivariate analysis revealed that age over 75 years (OR: 1.246, 95% CI: 1.176, 1.319), LDL/HDL ratio > 1.98 (OR: 1.245, 95% CI: 1.192, 1.302), history of heart failure (OR: 1.446, 95% CI: 1.143, 1.829), hypertension (OR: 1.274, 95% CI: 1.225, 1.325), diabetes (OR: 1.341, 95% CI: 1.278, 1.406), eGFRs < 60 ml/min·1.73m2 (OR: 1.179, 95% CI: 1.112, 1.249), family history of CAD (OR: 1.236, 95% CI: 1.108, 1.379), and high homocysteine levels (OR: 1.209, 95% CI: 1.029, 1.420) are independent predictors of MVD. The incidence of multivessel disease increased from 37.7 to 58.6% with an increase in the number of predictive factors, while the incidence of single vessel disease decreased from 62.3 to 41.4%. This trend was statistically significant (P trend < 0.001). CONCLUSIONS: MVD is strongly correlated with a range of risk factors including diabetes, hypertension, LDL/HDL ratio greater than 1.98, hyperhomocysteinemia, family history of CAD, reduced glomerular filtration rate (< 60 ml/(min·1.73m2), age over 75 years, and a history of heart failure. Furthermore, as the number of predictive factors increases, the odds ratio (OR) for patients with MVD also increases, reaching 2.344 times the OR for patients without any predictive factors.
Asunto(s)
Síndrome Coronario Agudo , Humanos , Masculino , Estudios Retrospectivos , Femenino , China/epidemiología , Anciano , Síndrome Coronario Agudo/epidemiología , Síndrome Coronario Agudo/mortalidad , Síndrome Coronario Agudo/diagnóstico , Síndrome Coronario Agudo/terapia , Persona de Mediana Edad , Factores de Riesgo , Incidencia , Medición de Riesgo , Pronóstico , Enfermedad de la Arteria Coronaria/epidemiología , Enfermedad de la Arteria Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/diagnóstico , Análisis Multivariante , Factores de Tiempo , Mortalidad HospitalariaRESUMEN
Head and neck squamous cell carcinoma (HNSCC) is the most common malignant tumor in the oral and maxillofacial regions, and long noncoding RNAs (lncRNAs) play crucial roles in the occurrence and progression of HNSCC. The lncRNA lnc-H2AFV-1 was found to be upregulated in HNSCC tissues; however, the function of lnc-H2AFV-1 in regulating HNSCC proliferation and the potential molecular mechanism is unclear. The present study evaluated the expression of lnc-H2AFV-1 in HNSCC tissues using quantitative real-time PCR (qPCR) and associated abundant lnc-H2AFV-1 expression with tumor size. Functionally, lnc-H2AFV-1 significantly promoted the proliferation of HNSCC cells in vitro and in vivo. Quantified N6-methyladenosine (m6A) RNA methylation and dot blot assays revealed that total m6A methylation in HNSCC cells was accompanied by lnc-H2AFV-1 expression. Western blotting showed that the expression of methyltransferase-like (METTL) 3 and METTL14 was consistent with that of lnc-H2AFV-1, whereas the expression of demethylase fat mass and obesity-associated (FTO) was contrary to that of lnc-H2AFV-1. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and MeRIP-qPCR revealed that lnc-H2AFV-1 overexpression led to the elevated expression and maximal m6A methylation of intraflagellar transport (IFT) 80 in HNSCC. In addition, METTL3/14 knockdown decreased IFT80 expression. Thus, our findings suggested that lnc-H2AFV-1 might be a biomarker that alters m6A modification by regulating the m6A methylases METTL3/14 and FTO and then mediating the downstream target IFT80 to promote HNSCC progression.
Asunto(s)
Neoplasias de Cabeza y Cuello , ARN Largo no Codificante , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Línea Celular Tumoral , Proliferación Celular/genética , Neoplasias de Cabeza y Cuello/genética , Humanos , Metiltransferasas/genética , Metiltransferasas/metabolismo , Pronóstico , ARN Largo no Codificante/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genéticaRESUMEN
The frequent occurrence of extreme climate events disrupts the regional water budget balance and leads to changes in the dry and wet conditions of the surface, making the water surplus and deficit more complex and variable. To explore the quantitative relationship between the spatiotemporal evolution of dry and wet conditions and meteorological factors in the Hexi Corridor under changing environmental conditions, the relative moisture index (MI) and FAO Penman-Monteith (FAO P-M) model were combined to construct a partial differential quantitative attribution model for dry and wet variations affected by climate factors in the Hexi Corridor. The results show that: (1) MI in the Hexi Corridor increased significantly (Z = 2.341) during 1960-2019, showing a wet-trend change, and the degree of drought increased from southeast to northwest in the Hexi Corridor. (2) The order of drought degree in four seasons is as follows: winter (- 0.95), spring (- 0.93), autumn (- 0.89) and summer (- 0.83). (3) The frequency of extreme drought, severe drought, moderate drought, and mild drought within 60 years of 21 meteorological stations accounted for 28.38%, 50.48%, 8.85%, and 7.38%, respectively, and the frequency above severe drought was the highest. (4) The sensitivity of meteorological factors gradually increased from northwest to southeast, and MI was the most sensitive to the change of precipitation (P), followed by net radiation (Rn), wind speed (u2), mean temperature (Tmean), relative humidity (RH) and maximum temperature (Tmax). MI was the least sensitive to the change of minimum temperature (Tmin). P is the most important meteorological variable that contributes to the increase of MI, followed by u2, Tmean, and Tmin. Rn, Tmax, and RH have the least influence, and the total contribution of the seven meteorological factors is 85.59%. Compared with the reference evapotranspiration, P is the main factor affecting the dry and wet variations in Hexi Corridor.
RESUMEN
The water ecological security pattern is a core factor. A scientific, accurate, and practical evaluation of water ecological security provides a theoretical basis for regional water ecological management. Using water resource data from five cities in the Hexi Corridor of Gansu Province (Jiuquan (JQ), Jiayuguan (JYG), Zhangye (ZY), Jinchang (JC), and Wuwei (WW)) from 2006 to 2021, a water ecological security evaluation index system based on the PSR (pressure-state-response) framework was constructed, covering 27 factors related to water resources, socio-economics, and the ecological environment. The main obstacle factors of water ecological security were identified using the obstacle degree model, and the grey GM(1,1) model was employed to predict water ecological security. Results indicated that the comprehensive assessment index of water ecology in the Hexi Corridor increased from 2006 to 2021, showing a transition from relatively unsafe (0.319) to basic safety and then to relatively safe (0.672). The pressure and response systems were the main limiting factors affecting water ecological security in the Hexi Corridor. After a slight decline in 2008, the overall spatial distribution continued to rise, with WW City and ZY City leading since 2016. ZY had a higher safety grade proportion (25%) compared to other areas in the Hexi region. The pressure system was the most significant obstacle to water ecological security after 2006. Prediction results indicated that the comprehensive evaluation index of water ecological security would continue to rise annually from 2022 to 2031, reaching a very safe level by 2025. The evaluation results provide a scientific basis for ecological security and risk decision-making in the study area.
RESUMEN
The sediment content and transport rate of rivers are crucial indicators reflecting soil erosion, water quality, and water resource management in a region. Studying changes in river sediment transport rates within a basin is essential for evaluating water quality, restoring water ecosystems, and implementing soil and water conservation measures. This study focused on the Shule River Basin and utilized various methods such as moving average, cumulative anomaly, Mann-Kendall mutation test, Mann-Kendall (M-K) trend test, Sen's slope estimation, Correlation analysis, wavelet analysis, R/S analysis, ARCGIS10.7 interpolation, non-uniformity coefficient, and concentration to analyze data from hydrologic stations at Changmapu (CMP), Panjiazhuang (PJZ), and Dangchengwan (DCW). The research examined the temporal and spatial characteristics of sediment transport rates and identified key driving factors. Findings revealed significant increases in annual sediment transport rates at CMP and PJZ by 12.227 and 4.318 kg/s (10a)-1, respectively, while DCW experienced a decrease of 0.677 kg/s (10a)-1. The sediment transport rate of the three stations had a sudden change around 1994. The average annual sediment transport rates displayed distinct cycles, with CMP, PJZ, and DCW showing cycles of 51a, 53a, and 29a respectively. Additionally, while CMP and PJZ exhibited a continuous upward trend in sediment transport rates, DCW showed a consistent decline. The annual average sediment transport rates of CMP, PJZ, and DCW were 1305.43 kg/s, 810.06 kg/s, and 247.80 kg/s, respectively. These research findings contribute to enhancing the comprehension of sediment dynamics in the arid region of northwest China and offer a theoretical basis for the restoration and management of ecological environments in similar areas in the future.
RESUMEN
Efficient water-saving irrigation techniques and appropriate nitrogen (N) application are keys to solving the problems of water scarcity and irrational fertilization in jujube cultivation. In this study, first, the effects of sand tube irrigation (STI) on surface and subsurface wetted characteristics were investigated using in-situ infiltration tests in a jujube garden. Compared with surface drip irrigation (SD), STI reduced surface wetted area by 57.4% and wetted perimeter of the surface wetted circle by 37.1% and increased subsurface maximum infiltration distance of wetting front by 64.9%. At the optimal sand tube depth of 20 cm, surface wetted area of the surface wetted circle decreased by 65.4% and maximum infiltration distance of the wetting front increased by 70.9%, compared with SD. Two-year field experiments then investigated the effects of STI and SD on soil water storage, jujube leaf chlorophyll, net photosynthetic rate, actual water consumption, fruit yield, and water (WUE) and N (NUE) use efficiencies at four levels of N (pure nitrogen: N1, 0; N2, 286 kg ha-1; N3, 381 kg ha-1; N4, 476 kg ha-1) at the same irrigation amount (45 mm irrigation-1, total of 8). Compared with SD, STI increased soil water storage 18.0% (2021) and 15.6% (2022) during the entire growth period and also chlorophyll content, nitrogen balance index, and net photosynthetic rate, with both increasing and then decreasing with increasing N. Compared with SD, STI increased yields by 39.1% and 36.5% and WUE by 44.3% and 39.7% in 2021 and 2022, respectively. Nitrogen use efficiency was 2.5 (2021) and 1.6 (2022) times higher with STI than with SD. STI combined with N3 had the highest yield, WUE, NUE, and net income and is thus recommended as the optimal water-N combination. In conclusion, STI combined with appropriate N application can be an effective water-saving irrigation technology alternative to SD in jujube cultivation in arid areas.
RESUMEN
Head and neck squamous cell carcinoma (HNSCC) is one of the most widespread malignancies worldwide. p53, as a transcription factor, can play its role in tumor suppression by activating the expression of numerous target genes. However, p53 is one of the most commonly mutated genes, which frequently harbors missense mutations. These missense mutations are nucleotide substitutions that result in the substitution of an amino acid in the DNA binding domain. Most p53 mutations in HNSCC are missense mutations and the mutation rate of p53 reaches 6585%. p53 mutation not only inhibits the tumor suppressive function of p53 but also provides novel functions to facilitate tumor recurrence, called gainoffunction (GOF). The present study focused on the prevalence and clinical relevance of p53 mutations in HNSCC, and further described how mutant p53 accumulates. Moreover, mutant p53 in HNSCC can interact with proteins, RNA, and exosomes to exert effects on proliferation, migration, invasion, immunosuppression, and metabolism. Finally, several treatment strategies have been proposed to abolish the tumorpromoting function of mutant p53; these strategies include reactivation of mutant p53 into wildtype p53, induction of mutant p53 degradation, enhancement of the synthetic lethality of mutant p53, and treatment with immunotherapy. Due to the high frequency of p53 mutations in HNSCC, a further understanding of the mechanism of mutant p53 may provide potential applications for targeted therapy in patients with HNSCC.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Humanos , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/genética , Mutación con Ganancia de Función , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/genética , Mutación , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
N7-methylguanosine (m7G) modification is closely related to the occurrence of tumors. However, the m7G modification of circRNAs in oral squamous cell carcinoma (OSCC) remains to be investigated. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) was used to measure the methylation levels of m7G and identify m7G sites in circRNAs in human OSCC and normal tissues. The host genes of differentially methylated and differentially expressed circRNAs were analyzed by Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, and circRNA-miRNA-mRNA networks were predicted using the miRanda and miRDB databases. The analysis identified 2348 m7G peaks in 624 circRNAs in OSCC tissues. In addition, the source of m7G-methylated circRNAs in OSCC was mainly the sense overlap region compared with normal tissues. The most conserved m7G motif in OSCC tissues was CCUGU, whereas the most conserved motif in normal tissues was RCCUG (R = G/A). Importantly, GO enrichment and KEGG pathway analysis showed that the host genes of differentially methylated and differentially expressed circRNAs were involved in many cellular biological functions. Furthermore, the significantly differentially expressed circRNAs were analyzed to predict the circRNA-miRNA-mRNA networks. This study revealed the whole profile of circRNAs of differential m7G methylation in OSCC and suggests that m7G-modified circRNAs may impact the development of OSCC.
RESUMEN
BACKGROUND: We aimed to demonstrate the regulatory effect of long non-coding RNA (lncRNA) ENAH-202 on oral squamous cell carcinoma (OSCC) development as well as its molecular mechanism. METHODS: We detected ENAH-202 expression in OSCC tissues and cell lines by quantitative real-time PCR (qPCR). The biological function of ENAH-202 was assessed in vitro and in vivo using CCK-8, colony formation assays, transwell assays, xenograft formation, and tail vein injection. The further molecular mechanism by which ENAH-202 promoted OSCC progression was identified using RNA pull-down, LS-MS/MS analysis, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP) assays. RESULTS: ENAH-202 was significantly upregulated in OSCC tissues and cells. ENAH-202 promoted OSCC cell proliferation, migration, and invasion in vitro and in vivo. The expression of enabled homolog (ENAH) and epithelial-to-mesenchymal transition (EMT)-related proteins was changed with the expression of ENAH-202. Moreover, ENAH-202 promoted the transcription of Vimentin (VIM) by binding with ZNF502, which can help ENAH-202 promote OSCC progression. CONCLUSIONS: ENAH-202 facilitated OSCC cell proliferation and metastasis by regulating ZNF502/VIM axis, which played an important role in OSCC progression.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , ARN Largo no Codificante , Vimentina , Humanos , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , MicroARNs/genética , Neoplasias de la Boca/genética , Neoplasias de la Boca/patología , ARN Largo no Codificante/genética , Carcinoma de Células Escamosas de Cabeza y Cuello , Espectrometría de Masas en Tándem , Vimentina/genéticaRESUMEN
BACKGROUND: Internal N7-methylguanosine (m7G) methylation in mammalian messenger RNAs (mRNAs) is essential in disease development. However, the status of internally m7G-modified mRNAs in oral squamous cell carcinoma (OSCC) remains poorly understood. METHODS: Methylated RNA immunoprecipitation sequencing (MeRIP-seq) was used to identify the m7G modification level of mRNAs and the expression of mRNAs between OSCC and normal tissues. These differentially methylated and expressed genes were subjected to Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and construction of protein-protein interaction (PPI) networks. Quantitative real-time PCR (qPCR) assay was performed to detect the expression of Baculoviral IAP Repeat Containing 3 (BIRC3) in vitro. The biological function of BIRC3 in OSCC was clarified using CCK-8, Transwell migration and Western blot assays. RESULTS: The m7G-mRNA profile showed 9514 unique m7G peaks within 7455 genes in OSCC tissues. In addition, the most conserved m7G motif within mRNAs in OSCC was GGARG (R = G/A). The identified m7G peaks were mainly distributed in the coding sequence region within mRNAs in OSCC. GO enrichment and KEGG pathway analyses showed that m7G-modified genes were closely related to cancer progression. m7G-modified hub genes were screened from the constructed PPI networks. Furthermore, BIRC3 with high m7G methylation showed high expression in OSCC cell lines, as confirmed by qPCR assay. Functionally, the knockdown of BIRC3 significantly inhibited the proliferation and migration ability of CAL-27 cells in vitro functional assays. In addition, the relative expression of E-cadherin expression was elevated, while Vimentin and N-cadherin protein expression was decreased in CAL-27 cells transfected with si-BIRC3. This study suggests that BIRC3 could promote OSCC proliferation and migration, which may be associated with involvement in epithelial-mesenchymal transition (EMT) progression. CONCLUSIONS: This paper constructed a transcriptome map of internal m7G in mRNAs, which provides potential research value to study the role of m7G methylation in OSCC.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Animales , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Neoplasias de la Boca/genética , Neoplasias de la Boca/metabolismo , Transcriptoma , Epigenoma , Neoplasias de Cabeza y Cuello/genética , Mamíferos/genética , Mamíferos/metabolismoRESUMEN
Long non-coding RNAs (LncRNAs), which are more than 200 nucleotides in length and with limited protein-coding potential, play vital roles in the pathogenesis, tumorigenesis, and angiogenesis of cancers. Aberrant expression of lncRNAs has been detected in various carcinomas and may be correlated with oncogenesis by affecting related genes expression. Recently, an increasing number of studies have reported on long intergenic non-protein coding RNA 460 (LINC00460) in human tumor fields. LINC00460 is upregulated in diverse cancer tissues and cells. The upregulated expression level of LINC00460 is correlated with larger tumor size, tumor node metastasis (TNM) stage, lymph node metastasis, and shorter overall survival. The regulatory mechanism of LINC00460 was complex and diverse. LINC00460 could act as a competitive endogenous RNA (ceRNA), directly bind with proteins or regulate multiple pathways, which affected tumor progression. Moreover, LINC00460 was also identified to increase drug resistance, and therefore, weaken the effectiveness of tumor treatment. It has become increasingly important to investigate the roles of LINC00460 in various cancers by different mechanisms. Therefore, a more comprehensive understanding of LINC00460 is crucial to expound on the cellular function and molecular mechanism of human cancers. In this review, we refer to studies concerning LINC00460 and provide the basis for the evaluation of LINC00460 as a predicted biomarker or potential therapeutic target in malignancies, and also provide ideas for the future research of lncRNAs similar to LINC00460.
Asunto(s)
Biomarcadores de Tumor/genética , Regulación Neoplásica de la Expresión Génica/genética , Neoplasias/genética , ARN Largo no Codificante/genética , Humanos , Neoplasias/patología , Regulación hacia ArribaRESUMEN
A self-design bioreactor system employing a fixed bed operation process with immobilized Bacillus subtilis AYC beads for NH4+-N removal from slightly polluted water was proposed. Polyvinyl alcohol and Na-alginate were used as a gel matrix to entrap Bacillus subtilis AYC to form the immobilized beads. The NH4+-N removal process was studied in a intermittent operation mode to examine the start-up and steady state behaviors of the immobilized AYC in the reactor. The results indicated that the reactor was in the start-up state during the first week. NH4+-N began to be steadily removal since the second week, and the nitrogen removal rate was between 84.61% and 96.19% when the hydraulic retention time (HRT) was 30 min. To apply Bacillus subtilis AYC to develop a practical nitrogen removal system and further understand its nitrogen removal ability, the bioreactor was continuously operated under different experimental perameters. The results showed that under the optimum conditions of an HRT of 20 min and DO of 3.77-5.80 mg/L, the NH4+-N removal rate reached 99.55%. The NH4+-N removal rate increased as the C/N ratio increased. However, a high C/N may cause a high residual carbon level in the effluent, therefore, the most suitable C/N ratio was 10. In addition, the results showed that the bioreactor system could remove many types of nitrogen such as NH4+-N, NO3--N and organic-N, and had a good performance for inorganic nitrogen removal from sewage.
Asunto(s)
Bacillus subtilis/metabolismo , Reactores Biológicos/microbiología , Compuestos de Amonio Cuaternario/metabolismo , Aguas del Alcantarillado/microbiología , Contaminantes Químicos del Agua/metabolismo , Eliminación de Residuos LíquidosRESUMEN
BACKGROUND: The conventional implant approach involves flap elevation, which may result in increased soft tissue and bone loss and postoperative morbidity. The flapless surgical technique, aided by three-dimensional medical imaging equipment, is regarded as a possible alternative to the conventional approach to alleviate the above issues. Several studies have been performed regarding the role of flapless implant surgery. However, the results are inconsistent and there is no robust synthesis of long-term evidence to better inform surgeons regarding which type of surgical technique is more beneficial to the long-term prognosis of patients in need of implant insertion. AIM: To compare the long-term clinical performance after flapless implant surgery to that after the conventional approach with flap elevation. METHODS: PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and grey literature databases were searched from inception to 23 September 2019. Randomised controlled trials (RCTs) and cohort studies comparing the long-term clinical performance after flapless implant surgery to that after the conventional approach over a follow-up of three years or more were included. Meta-analyses were conducted to estimate the odds ratios (ORs) or mean differences (MDs) and their 95% confidence intervals (CIs) between the long-term implant survival rate, marginal bone loss, and complication rate of the flapless and conventional groups. Subgroup analyses were carried out to account for the possible effects of the guided or free-hand method during flapless surgery. RESULTS: Ten articles, including four RCTs and six cohort studies, satisfied the eligibility criteria and nine of them were included in the meta-analysis. There was no significant difference between the long-term implant survival rate [OR = 1.30, 95%CI (0.37, 4.54), P = 0.68], marginal bone loss [MD = 0.01, 95%CI (-0.42, 0.44), P = 0.97], and complication rate [OR = 1.44, 95%CI (0.77, 2.68), P = 0.25] after flapless implant surgery and the conventional approach. Moreover, subgroup analyses revealed that there was no statistically significant difference between the implant survival rate [guided: OR = 1.52, 95%CI (0.19, 12.35), P = 0.70]; free-hand: n = 1, could not be estimated), marginal bone loss [guided: MD = 0.22, 95%CI (-0.14, 0.59), P = 0.23; free-hand: MD = -0.27, 95%CI (-1.10, 0.57), P = 0.53], or complication rate [guided: OR = 1.16, 95%CI (0.52, 2.63), P = 0.71; free-hand: OR = 1.75, 95%CI (0.66, 4.63), P = 0.26] in the flapless and conventional groups either with use of the surgical guide or by the free-hand method. CONCLUSION: The flapless surgery and conventional approach had comparable clinical performance over three years or more. The guided or free-hand technique does not significantly affect the long-term outcomes of flapless surgery.
RESUMEN
The purpose of this two-year study was to evaluate the histocompatibility and osteogenic properties of a composite material consisting of poly(l-co-d,l lactide) (PLDLA) and silica-based bioactive glass fibers in vivo. PLDLA and PLDLA/silica-based bioactive glass fibers pins were implanted into the erector spinae muscles and femurs of beagles. Muscle and bone tissue samples were harvested 6, 12, 16, 26, 52, 78, and 104 weeks after implantation. Histology analysis was used to assess the histocompatibility, angiogenesis, and bone-implant contact. Micro-computed tomography was used to evaluate bone formation around the pins. Immunohistochemistry and western blotting revealed the expression level of the osteogenesis-related proteins. Addition of bioactive glass was demonstrated to possess better histocompatibility and reduce the inflammatory reactions in vivo. Moreover, PLDLA/silica-based bioactive glass fibers pins were demonstrated to promote angiogenesis and increase osteogenesis-related proteins expression, and thus played a positive role in osteogenesis and osseointegration after implantation. Our findings indicated that a composite of PLDLA and silica-based bioactive glass fiber is a promising biodegradable material for clinical use.
Asunto(s)
Materiales Biocompatibles/química , Poliésteres/química , Dióxido de Silicio/química , Animales , Materiales Biocompatibles/farmacología , Cerámica/química , Cerámica/farmacología , Perros , Histocompatibilidad , Ensayo de Materiales , Osteogénesis/efectos de los fármacos , Poliésteres/farmacología , Prótesis e Implantes , Dióxido de Silicio/farmacologíaRESUMEN
The present study aimed to evaluate the mechanical and degradative properties of poly(L-co-D,L-lactic acid)/silicate bioactive glass fibers (PLDLA/SGFs) composite pins in vivo. Both PLDLA and PLDLA/SGFs pins were inserted into the erector spinae muscles and femurs of beagle dogs and were harvested 6, 12, 16, 26, 52, 78, and 104 weeks after insertion. Bone formation around the pins was evaluated by micro-computed tomography. Mechanical properties were measured by the shear strength test. Thermogravimetric analysis, differential scanning calorimetry, and gel permeation chromatography were used to assess the degradation of these materials. The surface and cross-sectional morphology of both pins were observed using a scanning electron microscope. The experimental data demonstrated that PLDLA/SGFs pins can support new bone formation due to the influence of bioactive glass fibers. PLDLA/SGFs composite pins had higher initial shear strength and were relatively stable for at least 26 weeks. The addition of bioactive glass fibers accelerated the degradation rate of the composite pins. Thus, PLDLA/SGFs composite pins have promising potential for bone fixation applications.