Ultrasound Assessment of the Rectus Femoris in Patients with Chronic Obstructive Pulmonary Disease Predicts Sarcopenia.

Purpose: Sarcopenia, an age-related loss of skeletal muscle mass and function, is frequent in patients with chronic obstructive pulmonary disease (COPD) and is linked to a poor prognosis. The diagnosis of sarcopenia requires specific equipment and is inconvenient to introduce into clinical practice. Ultrasound is an innovative method to assess muscle quantity. The objective of this research was to evaluate the use of ultrasound for prospectively screening for sarcopenia in COPD patients. Patients and Methods: A total of 235 stable patients with COPD were included in this observational study and divided into development and validation sets. The Asian Working Group for Sarcopenia standards were used to define sarcopenia. The thickness (RFthick) and cross-sectional area (RFcsa) of the rectus femoris were measured using ultrasound. Receiver operating characteristic curve analysis of RFthick and RFcsa was used to predict sarcopenia. Nomogram models were constructed based on RFthick, RFcsa, age and body mass index to identify sarcopenia. Results: Sarcopenia was present in 83 (35.32%) patients. Patients with sarcopenia had advanced age, decreased pulmonary function, decreased physical function and poor clinical outcomes. RFthick and RFcsa showed good predictive ability for sarcopenia in the development and validation sets. The nomogram based on RFthick and RFcsa could detect sarcopenia in COPD patients, and all had significant predictive performance in the development and validation sets. The calibration plot showed good agreement between the nomogram predictions and actual observations. Conclusion: The ultrasound measurement of the rectus femoris has potential for the clinical assessment of sarcopenia in patients with COPD.

Value of endorectal ultrasonography in the assessment of invasion staging of low rectal cancer with local progression after neoadjuvant radiochemotherapy / Valor de la ultrasonografía endorectal en la evaluación de la estadificación de la invasión del cáncer rectal bajo con progresión local, después de administrar radioquimioterapia neoadyuvante

Abstract Although stages T3 and T4 rectal cancer can be reduced to T1 or T2 after neoadjuvant radiochemotherapy, the accuracy of the endorectal ultrasonography (ERUS) for the post-radiochemotherapy evaluation of low rectal cancer has seldom been reported. We aimed to investigate the value of ERUS in the assessment of invasion staging in low rectal cancer with local progression, and the factors affecting its accuracy, after neoadjuvant radiochemotherapy. A total of 114 patients administered with neoadjuvant radiochemotherapy for stages II and III low rectal cancer (local stage T3/T4) from February 2018 to December 2020 were enrolled in the study. The changes in local lesions were evaluated using ERUS before and after radiochemotherapy, and compared with the pathological T staging. The accuracy of post-neoadjuvant radiochemotherapy re-staging examined with ERUS was evaluated, and univariate analysis was used to identify the factors affecting the accuracy. After neoadjuvant radiochemotherapy, the blood flow distribution within the lesion significantly declined (P<0.05), the max length and max thickness of the longitudinal axis of the lesion were reduced (P<0.05), and the uT staging was decreased (P<0.05), when compared with lesions before the treatment. Compared with postoperative pathological T staging, the accuracies of ERUS in T1, T2, T3 and T4 stages were 11.11%, 28.57%, 27.27% and 100%, respectively. Univariate analysis indicated that review time of ERUS, post-operative T staging and Wheeler rectal regression stage were factors affecting the accuracy of ERUS re-staging. ERUS is more accurate for T4 re-staging, follow-up reviewed six weeks after neoadjuvant radiochemotherapy and low regression tumors, with a high application value for the assessment of the efficacy of neoadjuvant radiochemotherapy for low rectal cancer.

Resumen Aunque el cáncer de recto en estadios T3 y T4 se puede reducir a T1 o T2 después de la radioquimioterapia neoadyuvante, rara vez se ha informado la precisión de la ecografía endorrectal (ERUS) para la evaluación posterior a la radioquimioterapia del cáncer de recto inferior. Nuestro objetivo fue investigar el valor de ERUS en la evaluación de la estadificación de la invasión en el cáncer de recto inferior con progresión local, después de la radioquimioterapia neoadyuvante y los factores que afectan su precisión. Se incluyeron en el estudio un total de 114 pacientes a los que se les administró radioquimioterapia neoadyuvante para el cáncer de recto inferior en estadios II y III (estadio local T3/T4), desde febrero de 2018 hasta diciembre de 2020. Los cambios en las lesiones locales se evaluaron mediante ERUS antes y después de la radioquimioterapia y se compararon con la estadificación patológica T. Se evaluó la precisión de la re-estadificación examinada con ERUS, después de la radioquimioterapia neoadyuvante y se utilizó un análisis univariado para identificar los factores que afectan su precisión. Después de la radioquimioterapia neoadyuvante, la distribución del flujo sanguíneo dentro de la lesión disminuyó significativamente (P<0,05), la longitud máxima y el espesor máximo del eje longitudinal de la lesión se redujeron (P<0,05) y la estadificación uT disminuyó (P<0,05), en comparación con las lesiones antes del tratamiento. En comparación con la estadificación T patológica posoperatoria, las precisiones de ERUS en las etapas T1, T2, T3 y T4 fueron del 11,11%, 28,57%, 27,27% y 100%, respectivamente. El análisis univariable indicó que el tiempo de revisión de ERUS, la estadificación T postoperatoria y la etapa de regresión rectal de Wheeler fueron factores que afectaron la precisión de la re-estadificación con ERUS. ERUS es más preciso para la re-estadificación de T4, el seguimiento seis semanas después de la radioquimioterapia neoadyuvante y en tumores de baja regresión, con un alto valor de aplicación para la evaluación de la eficacia de la radioquimioterapia neoadyuvante para el cáncer rectal bajo.

Global variation of soil microbial carbon-use efficiency in relation to growth temperature and substrate supply.

Soil microbial carbon-use efficiency (CUE), which is defined as the ratio of growth over C uptake, is commonly assumed as a constant or estimated by a temperature-dependent function in current microbial-explicit soil carbon (C) models. The temperature-dependent function (i.e., CUE = CUE0 + m × (T - 20)) simulates the dynamic CUE based on the specific CUE at a given reference temperature (i.e., CUE0) and a temperature response coefficient (i.e., m). Here, based on 780 observations from 98 sites, we showed a divergent spatial distribution of the soil microbial CUE (0.5 ± 0.25; mean ± SD) at the global scale. Then, the key parameters CUE0 and m in the above equation were estimated as 0.475 and -0.016, respectively, based on the observations with the Markov chain Monte Carlo technique. We also found a strong dependence of microbial CUE on the type of C substrate. The multiple regression analysis showed that glucose influences the variation of measured CUE associated with the environmental factors. Overall, this study confirms the global divergence of soil microbial CUE and calls for the incorporation of C substrate beside temperature in estimating the microbial CUE in different biomes.

Assessment of BAK1 activity in different plant receptor-like kinase complexes by quantitative profiling of phosphorylation patterns.

Plant receptor-like kinases (RLKs) constitute a large family of receptors coordinating developmental programs with adaptation to environmental stresses including immune defenses. BRI1-ASSOCIATED KINASE 1 (BAK1), a member of the plant RLK family, forms receptor complexes with multiple RLK proteins including BRI1, FLS2, EFR and BIK1 to regulate responses to growth hormones or PAMPs. RLK activation and signal initiation involve protein complex formation and phosphorylation/dephosphorylation between BAK1 and its interacting partners. To gain new insight into how phosphorylation contributes to BAK1-mediated signaling specificity, we first mapped the phosphorylation patterns of BAK1 associated with different RLK partners (BRI1, FLS2, EFR and BIK1). Quantitative phospho-pattern profiling by label-free mass spectrometry revealed that differential phosphorylation patterns of RLK partners resulted from altered BAK1 phosphorylation status. More interestingly, the study of two BAK1 mutants (T450A and C408Y) both showing severe defect in immune defense yet normal growth phenotype suggested that varied phosphorylation patterns of RLK partners by BAK1 could be the molecular basis for selective regulation of multiple BAK1-dependent pathways. Taken together, this phospho-pattern profiling strategy allowed for explicit assessment of BAK1 kinase activity in different RLK complexes, which would facilitate elucidation of BAK1 diverse functions in plant development, defense, and adaptation. BIOLOGICAL SIGNIFICANCE: BAK1 is a functionally important co-receptor known to interact with different receptor-like kinases (RLKs) to coordinate plant development and immune defenses. Our study first mapped the phosphorylation patterns of BAK1 associated with four RLK partners (BRI1, FLS2, EFR and BIK1), and further revealed that differential phosphorylation patterns of multiple RLK partners resulted from altered BAK1 phosphorylation status. More interestingly, the study of two BAK1 mutants suggested that varied phosphorylation patterns of RLK partners by BAK1 could be the basis for selective regulation of signaling pathways. Taken together, this phospho-pattern profiling strategy allowed for explicit assessment of BAK1 kinase activity in different RLK complexes, which would facilitate elucidation of BAK1 diverse functions in plant development, defense, and adaptation.