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The resected pâ ¢A-N2 non-small-cell lung cancer (NSCLC) patients who could benefit from postoperative radiotherapy (PORT) are not well-defined. The study explored the role of PORT on EGFR mutant and wild-type NSCLC patients. We retrospectively searched for resected pIIIA-N2 lung adenocarcinoma patients who underwent EGFR mutation testing. 80 patients with EGFR wild-type and 85 patients with EGFR mutation were included. 62 patients received PORT. In overall population, the median disease-free survival (DFS) was improved in PORT arm compared to non-PORT arm (22.9 vs. 16.1 months; p = 0.036), along with higher 2-year locoregional recurrence-free survival (LRFS) rate (88.3% vs. 69.3%; p = 0.004). In EGFR wild-type patients, PORT was associated with a longer median DFS (23.3 vs. 17.2 months; p = 0.044), and a higher 2-year LRFS rate (86.8% vs. 61.9%; p = 0.012). In EGFR mutant patients, PORT was not significantly correlated with improved survival outcomes. EGFR wild-type may a biomarker to identify the cohort that benefits from PORT.
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P(NMe2)3-mediated substrate-controlled annulations of azoalkenes with α-dicarbonyl compounds are reported, where the azoalkenes serve as either four or five-atom synthons chemoselectively. The azoalkene participates in annulation with isatins as a four-atom synthon to furnish the spirooxindole-pyrazolines, whereas it functions as a novel five-atom synthon in annulation with aroylformates, thereby leading to chemo- and stereoselective formation of pyrazolones. The synthetic utilities of the annulations have been demonstrated, and a novel TEMPO-mediated decarbonylation reaction is unveiled.
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Background: The global outbreak of COVID-19, and the limited availability of clinical treatments, forced researchers around the world to search for the pathogenesis and potential treatments. Understanding the pathogenesis of SARS-CoV-2 is crucial to respond better to the current coronavirus disease 2019 (COVID-19) pandemic. Methods: We collected sputum samples from 20 COVID-19 patients and healthy controls. Transmission electron microscopy was used to observe the morphology of SARS-CoV-2. Extracellular vesicles (EVs) were isolated from sputum and the supernatant of VeroE6 cells, and were characterized by transmission electron microscopy, nanoparticle tracking analysis and Western-Blotting. Furthermore, a proximity barcoding assay was used to investigate immune-related proteins in single EV, and the relationship between EVs and SARS-CoV-2. Result: Transmission electron microscopy images of SARS-COV-2 virus reveal EV-like vesicles around the virion, and western blot analysis of EVs extracted from the supernatant of SARS-COV-2-infected VeroE6 cells showed that they expressed SARS-COV-2 protein. These EVs have the infectivity of SARS-COV-2, and the addition can cause the infection and damage of normal VeroE6 cells. In addition, EVs derived from the sputum of patients infected with SARS-COV-2 expressed high levels of IL6 and TGF-ß, which correlated strongly with expression of the SARS-CoV-2 N protein. Among 40 EV subpopulations identified, 18 differed significantly between patients and controls. The EV subpopulation regulated by CD81 was the most likely to correlate with changes in the pulmonary microenvironment after SARS-CoV-2 infection. Single extracellular vesicles in the sputum of COVID-19 patients harbor infection-mediated alterations in host and virus-derived proteins. Conclusions: These results demonstrate that EVs derived from the sputum of patients participate in virus infection and immune responses. This study provides evidence of an association between EVs and SARS-CoV-2, providing insight into the possible pathogenesis of SARS-CoV-2 infection and the possibility of developing nanoparticle-based antiviral drugs.
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COVID-19 , Vesículas Extracelulares , Humanos , COVID-19/metabolismo , SARS-CoV-2 , Integrinas/metabolismo , Esputo , Proteómica/métodos , Vesículas Extracelulares/metabolismo , Tetraspanina 28RESUMEN
Introduction: Cellular adaptation to physical training and energy metabolism play an important role during physical exercise. This study sought to investigate the effects of α-KG on cell growth and energy metabolism in C2C12 cell culture. Methods: C2C12 cells were cultured in media pretreated without (control) or with α-KG at different concentrations, and cells and media were harvested every 24 h for 8 days. From cell counts, specific cell growth rate (SGR) and doubling time were calculated. The content of glucose, glutamine, lactate, and ammonia in media was determined, and the specific consumption rate (SCR) or production rate (SPR) was calculated. Additionally, cell colony-forming efficiency (CFE) was determined. Results: The control cells showed a CFE at 50%, a typical cell growth curve in the first 5 days with a mean SGR at 0.86/day, and a mean cell count doubling time at 19.4 h. In the group with α-KG at 100 mM, the cells underwent rapid cell death, and thus no further analysis was made. The treatment with α-KG at lower concentrations (0.1 mM and 1.0 mM) led to a higher CFE at 68 and 55%, respectively, whereas those in groups with higher α-KG concentration decreased (10 and 6% for 20 mM and 30 mM α-KG, respectively). The mean SGR was 0.95/day, 0.94/day, 0.77/day, 0.71/day, and 0.65/day for groups treated with α-KG at 0.1, 1.0, 10.0, 20.0, and 30.0 mM, respectively, and the corresponding cell count doubling time was 17.6, 17.8, 20.9, 24.6, and 24.7 h, respectively. In comparison with that of the control group, the mean glucose SCR decreased in all the groups treated with α-KG, while the mean glutamine SCR remained unchanged; the mean lactate SPR increased in the groups treated with α-KG ≥ 20.0 mM. Finally, the mean SPR of ammonia was lower in all α-KG groups than that in the control. Discussion and conclusion: The treatment with α-KG at lower concentrations increased cell growth whereas at higher concentrations decreased cell growth, and α-KG reduced glucose consumption and ammonia production. Therefore, α-KG stimulates cell growth in a dose-dependent manner, which is likely through the improvement of glucose and glutamine metabolism in a C2C12 culture setting.
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Speckle-tracking echocardiography (STE) has become an established, widely available diagnostic method in the past few years, making its value clear in cases of COVID-19 and the further course of the disease, including post-COVID syndrome. Since the beginning of the pandemic, many studies have been published on the use of STE in this condition, enabling, on the one hand, a better understanding of myocardial involvement in COVID-19 and, on the other, a better identification of risk to patients, although some questions remain unanswered in regard to specific pathomechanisms, especially in post-COVID patients. This review takes a closer look at current findings and potential future developments by summarising the extant data on the use of STE, with a focus on left and right ventricular longitudinal strain.
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Tumor metastasis is a hallmark of colorectal cancer (CRC), in which exosome plays a crucial role with its function in intercellular communication. Plasma exosomes were collected from healthy control (HC) donors, localized primary CRC and liver-metastatic CRC patients. We performed proximity barcoding assay (PBA) for single-exosome analysis, which enabled us to identify the alteration in exosome subpopulations associated with CRC progression. By in vitro and in vivo experiments, the biological impact of these subpopulations on cancer proliferation, migration, invasion, and metastasis was investigated. The potential application of exosomes as diagnostic biomarkers was evaluated in 2 independent validation cohorts by PBA. Twelve distinct exosome subpopulations were determined. We found 2 distinctly abundant subpopulations: one ITGB3-positive and the other ITGAM-positive. The ITGB3-positive cluster is rich in liver-metastatic CRC, compared to both HC group and primary CRC group. On the contrary, ITGAM-positive exosomes show a large-scale increase in plasma of HC group, compared to both primary CRC and metastatic CRC groups. Notably, both discovery cohort and validation cohort verified ITGB3+ exosomes as potential diagnostic biomarker. ITGB3+ exosomes promote proliferation, migration, and invasion capability of CRC. In contrast, ITGAM+ exosomes suppress CRC development. Moreover, we also provide evidence that one of the sources of ITGAM+ exosomes is macrophage. ITGB3+ exosomes and ITGAM+ exosomes are proven 2 potential diagnostic, prognostic, and therapeutic biomarkers for management of CRC.
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Patients with hypertrophic cardiomyopathy (HCM), which is characterized by left ventricular hypertrophy, is usually treated with medications such as calcium channel blockers or beta-blockers and invasive treatments such as transcatheter alcohol septal ablation, percutaneous radiofrequency ablation, or heart transplantation. However, non-invasive methods have not been employed for the management of patients with HCM. A 71-year-old male who presented with occasional chest pain for approximately 2 months and had been diagnosed with HCM since he was 39 years old due to occasional fainting was treated with a novel method for HCM using stereotactic body radiotherapy (SBRT). The administration of 25 Gy of radiation as one fraction led to an improvement in his quality of life. No toxicity occurred during or immediately after the treatment. Our observations suggest that SBRT may be a reasonable treatment approach for patients with HCM who are not suitable for surgery.
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Escoliosis , Humanos , Rotación , Escoliosis/diagnóstico por imagen , Escoliosis/cirugía , Vértebras TorácicasRESUMEN
BACKGROUND: Acute coronary syndrome (ACS) causes pathophysiological changes in exercise capacity, N-terminal part of pro-brain natriuretic peptide (NT-proBNP), and adiponectin that impact the course of coronary artery disease and clinical outcomes after cardiac rehabilitation (CR). However, the serial changes and the relationship between the changes in these parameters for a prolonged term remain uninvestigated. METHODS: Eighty-one patients with ACS underwent a three- or four-week CR program after acute care and were followed up for 12 months. Exercise capacity on a cycle ergometer and blood levels of NT-proBNP and adiponectin were determined before and after CR as well as at the 12-month follow-up. RESULTS: Exercise capacity increased from 100 watts (in median) before CR to 138 watts after CR and 150 watts at 12 months. The NT-proBNP level (526 pg/ml before CR) remained almost unchanged after CR (557 pg/ml) and then decreased at 12 months (173 pg/ml). The adiponectin level (14.5 µg/ml before CR) increased after CR (16.0 µg/ml) and at 12 months (17.2 µg/ml). There was no significant correlation among the changes in these parameters at each observation time point. CONCLUSION: During the observation period from before CR to the 12-month follow-up, exercise capacity, NT-proBNP, and adiponectin underwent significant changes; however, these changes were independent from each other and not correlated linearly, and they provide complementary information in clinical practice. Thus, all these parameters should be included and determined at different time points for a prolonged period of time.
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The aim of this study was to evaluate the outcomes of surgical treatment of intra-articular calcaneal fractures by using the sinus tarsi approach combined with percutaneous medial reduction by leverage technique and percutaneous screw fixation. We assessed the outcomes of 29 patients treated using sinus tarsi approach with percutaneous screw fixation. All patients were evaluated both clinically and radiologically. The Böhler and Gissane angle were evaluated postoperatively using radiographs. During the median follow-up period of 27.0 ± 10.3 months, no cases with failure to reduce or displace hardware were detected. All cases achieved the restoration of a normal Böhler and Gissane angle. The median preoperative Böhler angle was 12.3° ± 2.5° while postoperatively it was 30.5° ± 5.7° (p < .01). The median preoperative Gissane angle was 98.1° ± 7.5°, which was 125.9° ± 3.6° postoperatively (p < .01). At the last follow-up, the median American Orthopedic Foot and Ankle Society hindfoot score was 87.7 ± 5.9, and the median Maryland foot score was 88.6 ± 5.9. Our technique for intra-articular calcaneal fractures can effectively correct calcaneal tuberosity outward displacement, medial wall overlapping, and the hindfoot varus deformity with less soft tissue damage. This technique is a good alternative for the treatment of calcaneal fractures, resulting in minimal soft tissue damage, few wound complications, and excellent radiological and clinical outcomes.
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Traumatismos del Tobillo , Calcáneo , Traumatismos de los Pies , Fracturas Óseas , Fracturas Intraarticulares , Traumatismos de la Rodilla , Traumatismos del Tobillo/etiología , Placas Óseas , Tornillos Óseos , Calcáneo/diagnóstico por imagen , Calcáneo/cirugía , Traumatismos de los Pies/etiología , Fijación Interna de Fracturas/métodos , Fracturas Óseas/diagnóstico por imagen , Fracturas Óseas/etiología , Fracturas Óseas/cirugía , Talón/cirugía , Humanos , Fracturas Intraarticulares/diagnóstico por imagen , Fracturas Intraarticulares/cirugía , Resultado del TratamientoRESUMEN
PURPOSE: The purpose of this study was to compare the clinical outcomes of intra-articular calcaneal fractures with medial column displacement treated with different surgical techniques, namely extensile lateral approach (ELA) or sinus tarsi approach (STA), combined with percutaneous medial reduction. METHODS: Ninety-six patients with intra-articular calcaneal fractures who were subjected to ELA or STA (45 in STA group and 51 in ELA group) were retrospectively assessed. Reduction of the posterior facet, calcaneal body, Böhler's angle, and Gissane's angle were evaluated. Clinical outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score and visual analog scale (VAS). The complications, time to surgery, operative time, and blood loss were also assessed. RESULTS: Incidence of wound complications, post-operative blood drainage, and time to the operation were significantly different between the two groups. There was no significant difference in the recovery of calcaneal anatomy and articular surface between the two groups. Similarly, no difference was detected in Böhler's and Gissane's angles between ELA and STA groups (P > 0.05). Finally, there was no difference in AOFAS and VAS scores between the two groups at the final follow-up (P > 0.05). CONCLUSION: STA resulted in favourable radiological and clinical results with fewer wound complications and a shorter waiting time when compared to ELA. The percutaneous medial reduction technique is effective in reducing medial column displacement.
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Calcáneo , Fracturas Óseas , Fracturas Intraarticulares , Calcáneo/diagnóstico por imagen , Calcáneo/cirugía , Fijación Interna de Fracturas , Fracturas Óseas/diagnóstico por imagen , Fracturas Óseas/cirugía , Humanos , Fracturas Intraarticulares/diagnóstico por imagen , Fracturas Intraarticulares/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The coronavirus disease 2019 (COVID-19) pandemic is currently the most critical challenge in public health. An understanding of the factors that affect severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection will help fight the COVID-19 pandemic. This study sought to investigate the association between SARS-CoV-2 infection and blood type distribution. The big data provided by the World Health Organization (WHO) and Johns Hopkins University were used to assess the dynamics of the COVID-19 epidemic. The infection data in the early phase of the pandemic from six countries in each of six geographic zones divided according to the WHO were used, representing approximately 5.4 billion people around the globe. We calculated the infection growth factor, doubling times of infection and death cases, reproductive number and infection and death cases in relation to the blood type distribution. The growth factor of infection and death cases significantly and positively correlated with the proportion of the population with blood type A and negatively correlated with the proportion of the population with blood type B. Compared with the lower blood type A population (<30%), the higher blood type A population (⩾30%) showed more infection and death cases, higher growth factors and shorter case doubling times for infections and deaths and thus higher epidemic dynamics. Thus, an association exists between SARS-CoV-2 and the ABO blood group distribution, which might be useful for fighting the COVID-19 pandemic.
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Sistema del Grupo Sanguíneo ABO , COVID-19/epidemiología , SARS-CoV-2 , Número Básico de Reproducción , COVID-19/sangre , HumanosAsunto(s)
Aneurisma Cardíaco , Ventrículos Cardíacos , Infarto del Miocardio sin Elevación del ST , Stents Liberadores de Fármacos , Electrocardiografía , Aneurisma Cardíaco/complicaciones , Aneurisma Cardíaco/diagnóstico , Aneurisma Cardíaco/patología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio sin Elevación del ST/complicaciones , Infarto del Miocardio sin Elevación del ST/fisiopatologíaRESUMEN
AIM: To investigate blood supply features of the flap based on the plantar digital artery arch and arch branch artery, and the treatment of outcomes of reconstructed fingers by the plantar digital artery arch branch island flap. METHODS: Eight fresh foot specimens were employed with red emulsion infusion and microdissection. The vascular organization was observed in the second toe, such as initiation site, the course, and the number of the plantar digital artery arch branch. There were 15 fingers of 13 patients (8 males and 5 females) with finger defects accompanied by toe transfer, using the plantar digital artery arch branch flap inserted in the neck of the second toe to correct the appearance defect caused by a narrow "neck" and a bulbous tip. RESULTS: The intact plantar digital arches were identified in all specimens. The plantar digital artery arch had 5 branches. The range of external diameter of the arch branch was 0.4-0.6 mm. All the plantar digital artery arch branch island flaps and the reconstructed fingers survived. These cases were conducted with a follow-up period for 3-18 months (average, 9 months). All the plantar digital artery arch branch island flaps and reconstructed fingers demonstrated a satisfactory appearance and favorable sense function. The reconstructed finger-tip characteristic was good, with no obvious scar hyperplasia. The range of flexion and extension of reconstructed fingers was favorable as well. CONCLUSIONS: The plantar digital artery arch and arch branch artery possess regular vasa vasorum and abundant vascularity. A flap based on the plantar digital artery arch branch is an ideal selection for plastic surgery of reconstructed fingers.
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Traumatismos de los Dedos/cirugía , Procedimientos de Cirugía Plástica/métodos , Colgajos Quirúrgicos/irrigación sanguínea , Dedos del Pie/irrigación sanguínea , Dedos del Pie/trasplante , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto JovenRESUMEN
Previous studies have suggested that estradiol can reduce the ischemia/reperfusion (I/R) injury in skin flaps. However, the mechanism, particularly the signal pathways involved in this protective effect are not well established. In the current study, an I/R injury model was established in rats to explore the connection between estradiol protection during I/R injury and extracellular signalregulated kinase (ERK) signaling. Healthy male Wistar rats were divided into five groups (n=10): Control group (group I), I/R group (group II), saline group (group III), estradiol group (group IV) and inhibitor (PD98059) group (group V). The survival rate of the flap was compared between groups, morphological changes were observed by hematoxylin and eosin staining of sections, and terminal deoxynucleotidyl transferase dUTP nick end labeling was performed to identify apoptotic cells and determine the apoptotic index. To further investigate the mechanism, western blot analysis was performed to assess the protein level of ERK1/2, phosphoERK1/2, and mitogenactivated protein kinase phosphatase 1 (MKP1). The results of the present study demonstrated that estradiol therapy can reduce I/R injury and decrease the apoptosis index in an axial skin flap model. The inhibitor of the ERK pathway (PD98059) partially abolished the effects of estradiol, which involve the phosphatase enzyme MKP1. Taken together, the findings of the present study indicate that estradiol may act by reducing the expression of MKP1, mediating the expression/activation changes of the ERK pathway and subsequently reduce the level of apoptosis and the I/R injury the axial flap. Estrogen may be used to mitigate the adverse reaction caused by ischemiareperfusion injury and effectively improve the survival rate and survival quality of free skin flap and improve patient prognosis.
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Apoptosis/efectos de los fármacos , Estradiol/farmacología , Daño por Reperfusión/patología , Transducción de Señal/efectos de los fármacos , Piel/patología , Animales , Fosfatasa 1 de Especificidad Dual/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Supervivencia de Injerto/efectos de los fármacos , Masculino , Inhibidores de Proteínas Quinasas/farmacología , Ratas , Ratas Wistar , Daño por Reperfusión/metabolismo , Daño por Reperfusión/veterinaria , Piel/irrigación sanguínea , Piel/metabolismo , Trasplante de Piel , Colgajos QuirúrgicosRESUMEN
Accurate location computation for a beacon is an important factor of the reliability of satellite optical communications. However, location precision is generally limited by the resolution of CCD. How to improve the location precision of a beacon is an important and urgent issue. In this paper, we present two precise centroid computation methods for locating a beacon in satellite optical communications. First, in terms of its characteristics, the beacon is divided into several parts according to the gray gradients. Afterward, different numbers of interpolation points and different interpolation methods are applied in the interpolation area; we calculate the centroid position after interpolation and choose the best strategy according to the algorithm. The method is called a "gradient segmentation interpolation approach," or simply, a GSI (gradient segmentation interpolation) algorithm. To take full advantage of the pixels of the beacon's central portion, we also present an improved segmentation square weighting (SSW) algorithm, whose effectiveness is verified by the simulation experiment. Finally, an experiment is established to verify GSI and SSW algorithms. The results indicate that GSI and SSW algorithms can improve locating accuracy over that calculated by a traditional gray centroid method. These approaches help to greatly improve the location precision for a beacon in satellite optical communications.
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In deep space optical communications, it is very difficult to acquire the beacon given the long communication distance. Acquisition efficiency is essential for establishing and holding the optical communication link. Here we proposed a quick acquisition and recognition method for the beacon in deep optical communications based on the characteristics of the deep optical link. To identify the beacon from the background light efficiently, we utilized the maximum similarity between the collecting image and the reference image for accurate recognition and acquisition of the beacon in the area of uncertainty. First, the collecting image and the reference image were processed by Fourier-Mellin. Second, image sampling and image matching were applied for the accurate positioning of the beacon. Finally, the field programmable gate array (FPGA)-based system was used to verify and realize this method. The experimental results showed that the acquisition time for the beacon was as fast as 8.1s. Future application of this method in the system design of deep optical communication will be beneficial.
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OBJECTIVE: To evaluate the effectiveness of free flaps in repairing hot-crush injury in the dorsum of hand. METHODS: Between February 2003 and February 2012, 32 cases of hot-crush injuries in the dorsum of hand were repaired. There were 25 males and 7 females with an average age of 24 years (range, 16-45 years). The injury causes included machine crush injury in 9 cases, machine-press injury in 13 cases, and iron panel injury in 10 cases. The time from injury to admission ranged from 90 minutes to 8 hours (mean, 3 hours). The wound size ranged from 6 cm x 5 cm to 17 cm x 11 cm. Associated injuries included the extensor tendon necrosis in 12 cases, and the second metacarpal bone necrosis in 1 case. One-stage emergency debridement was performed in all cases; two-stage flap repair was given at 7-21 days when the necrotic area became determined. The dorsalis pedis flaps were used in 9 cases, the anterolateral thigh flaps in 9 cases, the latissimus dorsi flaps in 3 cases, the thoraco-umbilical flaps in 3 cases, and the lower abdominal flaps in 8 cases. The flap size ranged from 7 cm x 5 cm to 18 cm x 16 cm. The donor site was repaired by skin graft or sutured directly. RESULTS: All the flaps survived. Primary healing of wound was obtained in 25 cases and delayed healing in 7 cases. Skin graft at donor site survived, with healing of incision by first intention. Twenty-three cases were followed up 6-25 months (mean, 13 months). Thinning was carried out in 8 bulky flaps; the other flaps had good appearance and texture. At last follow-up, the range of motion (ROM) of the metacarpophalangeal joint ranged from 40 to 80 degrees (mean, 58 degrees); ROM of the proximal interphalangeal joint ranged from 35 to 70 degrees (mean, 52 degrees); and ROM of the distal interphalangeal joint ranged from 5 to 25 degrees (mean, 12 degrees). The sensation recovery of the flaps were more than S2. No scar formed at donor site. CONCLUSION: Suitable free flap should be selected to repair hot-crush injury in the dorsum of hand according to size of wound, which will achieve satisfactory results.
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Quemaduras/cirugía , Colgajos Tisulares Libres , Traumatismos de la Mano/cirugía , Trasplante de Piel/métodos , Adolescente , Adulto , Quemaduras/complicaciones , Desbridamiento , Femenino , Traumatismos de los Dedos/cirugía , Estudios de Seguimiento , Supervivencia de Injerto , Humanos , Masculino , Articulación Metacarpofalángica/cirugía , Persona de Mediana Edad , Necrosis , Rango del Movimiento Articular , Procedimientos de Cirugía Plástica/métodos , Piel/patología , Traumatismos de los Tejidos Blandos/cirugía , Resultado del Tratamiento , Cicatrización de Heridas , Adulto JovenRESUMEN
To address possible effects of heat shock protein 70 (Hsp70) on energy metabolism, we established a cell line expressing different levels of Hsp70 and evaluated changes in glucose and lactate metabolites, as well as ATP levels accordingly. In addition, activities of enzymes involved in glycolysis [phosphofructokinase (PFK) and lactate dehydrogenase (LDH)], Krebs cycle [citric synthase (CS)], and oxidative phosphorylation {NADH dehydrogenase [complex I (CI)] and ubiquinol:cytochrome-c reductase [complex III (CIII)]} were analyzed. The results show that both glucose consumption and lactate excretion were elevated significantly in cells expressing increased levels of Hsp70. Simultaneously, the activities of glycolytic enzymes PFK and LDH were increased markedly in cells overexpressing Hsp70. Activities of enzymes CI and CIII, both involved in oxidative phosphorylation, decreased upon increased expression of Hsp70. These findings were supported by nonsignificant reductions of CS activities in cells that overexpressed Hsp70, whereas intracellular ATP levels remained constant over a wide range of Hsp70 expression. In conclusion, overexpression of Hsp70 in HeLa cells results in downregulation of oxidative phosphorylation, in particular, multiprotein CIII, the main source of reactive oxygen species. In exchange, upregulation of the glycolytic pathway compensates for the homeostasis of cellular ATP supply.
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Adenosina Trifosfato/metabolismo , Glucólisis , Proteínas HSP70 de Choque Térmico/metabolismo , Mitocondrias/metabolismo , Fosforilación Oxidativa , Adaptación Fisiológica , Citrato (si)-Sintasa/metabolismo , Ciclo del Ácido Cítrico , Complejo I de Transporte de Electrón/metabolismo , Complejo III de Transporte de Electrones/metabolismo , Regulación de la Expresión Génica , Glucosa/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Células HeLa , Humanos , L-Lactato Deshidrogenasa/metabolismo , Ácido Láctico/metabolismo , Fosfofructoquinasas/metabolismo , TransfecciónRESUMEN
BACKGROUND: Exercise causes a variety of physiological and metabolic changes that can in turn reduce exercise tolerance. One of the potential mechanisms responsible for fatigue is "exercise-induced hyperammonemia". Previous studies have shown that supplementation with amino acids can increase training tolerance. The α-keto acids are biochemical analogs of amino acids and can be converted to amino acids through transamination, thus reducing the cellular ammonia level. This double blind, placebo-controlled study was designed to investigate the effects of α-keto acid supplementation (KAS) on training tolerance, training effect, and stress-recovery state. METHODS: Thirty-three untrained young male adults underwent four weeks of training (5 sessions/week; 30 minutes running at the individual anaerobic threshold followed by 3 x 3 minute sprints/each session). Throughout the 4 weeks of training and one week of recovery, subjects took α-ketoglutarate (AKG group, 0.2 g/kg/d, n = 9), branched-chain keto acids (BCKA group, 0.2 g/kg/d, n = 12) or isocaloric placebo (control group, n = 12) daily. RESULTS: The 4th week training volume, maximum power output and muscle torque were higher in the AKG group (175 ± 42 min, 412 ± 49 Watts and 293 ± 58 Newton meters, respectively, P<0.05) and the BCKA group (158 ± 35, 390 ± 29 and 273 ± 47, P<0.05) than in the control group (92 ± 70, 381 ± 67 and 233 ± 43). The general stress and emotional exhaustion as assessed by the rest-stress-questionnaire-sport after the 3rd week of training increased significantly in the control group (P<0.05), but not in the KAS groups. CONCLUSIONS: Under KAS, subjects could bear a higher training volume and reach a higher power output and peak muscle torque, accompanied by a better stress-recovery-state. Thus, KAS improves exercise tolerance and training effects along with a better stress-recovery state. Whether the improved training tolerance by KAS is associated with effects on ammonia homeostasis requires further observation.