Curso Temporal de los Efectos Agudos de una Sesión de Estiramiento Muscular en Sujetos Jóvenes y Sanos / Time Course of the Acute Effects of a Muscle Stretching Session in Young and Healthy Subjects

Introducción. La duración de los efectos agudos del estiramiento muscular y su relación con el volumen total de estiramiento es un tema controversial. Método. Se distribuyeron aleatoriamente 29 varones jóvenes y deportistas en tres grupos: Control, "protocolo corto" (5 estiramientos x 30' segundos) y "protocolo largo" (10 estiramientos x 30 segundos). Para medir el efecto se usó el Active Knee Extension Test en forma previa y posterior a los 0, 3, 7, 12, 18 y 25 minutos. Cada medición se grabó en video, y se identificó el rango máximo de estiramiento con el software Kinovea. Se realizó comparación pre y postintervención entre grupos e inter grupo. Se incorporó análisis post hoc en medidas repetidas. Resultados. No hubo diferencias en la medición preintervención entre los grupos (P=0,266). Ambos protocolos tuvieron cambios significativos (P<0,007) respecto del grupo control (P=0,65). Todas las mediciones postintervención comparadas con la preintervención presentan diferencias en el protocolo corto (P≤0,018) y largo (P≤0,009). Hubo diferencia entre el grupo control con el de protocolo corto (P≤0,014) y control con protocolo largo (P≤0,004) para todas las mediciones, y una diferencia entre ambos protocolos en el post inmediato (P=0,033) pero no para las mediciones posteriores (P≤0,139). Conclusión. Un protocolo de 150 segundos de estiramiento estático en isquiotibiales en varones asintomáticos jóvenes, presenta efectos por al menos 25 minutos. Al duplicar a 300 segundos sólo presenta diferencia en la medición inmediatamente posterior. Por lo tanto, ambos protocolos son igualmente efectivos, pero el protocolo corto es más eficiente.

Background. The duration of the acute effects of muscle stretching and its relationship with the total volume of stretching is a controversial issue. Methods. 29 young male athletes were randomly distributed into three groups: control, "short protocol" (5 stretches x 30'') and "long protocol" (10 stretches x 30''). To measure the effect, the Active Knee Extension Test was used before and after 0, 3', 7', 12', 18' and 25'. Each measurement was videotaped, and the maximum range of stretch was identified using the Kinovea software. A pre-post intervention comparison was made between groups and inter groups. Post hoc analysis was incorporated into repeated measures. Results. There were no differences in the pre-intervention measurement between the groups (P=0.266). Both protocols had significant changes (P<0.007) compared to the control group (P=0.65). All post-intervention measurements compared to pre-intervention present differences in the short (P≤0.018) and long (P≤0.009) protocol. There was a difference between the control group with the short protocol (P≤0.014) and the control group with the long protocol (P≤0.004) for all measurements, and a difference between both protocols in the immediate post (P=0.033) but not for the measurements. subsequent measurements (P≤0.139). Conclusion. A protocol of 150'' of static stretching in hamstrings in asymptomatic young men, presents effects for at least 25'. When doubling at 300'', it only presents a difference in the immediately subsequent measurement. Therefore, both protocols are equally effective, but the short protocol is more efficient.

Novel articulating through-the-scope traction device.

Video 1Parts and functions of the novel articulating traction device with its application in gastric and colonic endoscopic submucosal dissection procedures.

Ameloblastoma with adenoid features: Case report with cyto-histopathologic correlation and molecular findings.

Ameloblastomas are benign but locally aggressive odontogenic tumors that commonly present as expansile lesions in the tooth-bearing areas. Fine-needle aspiration (FNA) biopsies of ameloblastomas are rare in clinical practice, and only a handful of case reports and series have described their cytologic features. We present the case of a 70-year-old woman with a large and disfiguring maxillary sinus soft tissue mass sampled via transcutaneous FNA. Aspirate smears were composed of small clusters of cohesive and monotonous basaloid cells. The accompanying cellblock showed similar clusters of basaloid cells in gland-like, or "adenoid," configurations, eliciting a differential diagnosis that included sinonasal and salivary gland neoplasms. Excisional surgery material was consistent with ameloblastoma with adenoid morphology. Next-generation sequencing (NGS) analysis demonstrated FGFR2 and SMO pathogenic variants. This case exemplifies several uncommonly described features of ameloblastomas in cytology, including cyto-histologic correlation, adenoid morphology, and NGS findings. Awareness of the cytologic features of this neoplasm are important for cytopathologists confronted with maxillary sinus lesions.

Distinct patterns of gene expression in human cardiac fibroblasts exposed to rapamycin treatment or methionine restriction.

Both methionine restriction and rapamycin treatment are robust longevity-enhancing regimens for which the mechanisms remain unclear. Cellular senescence is a major contributor to the aging process, and we find that both the methionine and rapamycin regimens delay or prevent activation of the senescence program in human cells. Using a transcriptome-wide analysis, we examined the impact of methionine restriction and rapamycin treatment on senescence-associated gene expression in human cardiac fibroblasts. Our findings have been integrated into gene expression data sets from human lung and skin fibroblasts during senescence. The data demonstrate both common and tissue-specific aspects to the senescent phenotype in these cell types. For example, cardiac fibroblasts express brain naturetic peptide, a clinically relevant marker for cardiac failure, whereas senescent cells from all three tissues express at least one of the insulin-like growth factor (IGF)-binding proteins. The IGF-binding proteins are tissue-specific mediators of IGF-1, a growth factor required for proliferation of all tissues. These data suggest that senescent cells serve tissue-specific roles. Moreover, the prolongevity regimens produce distinct patterns of gene expression.

Mechanisms underlying iron and copper ions toxicity in biological systems: Pro-oxidant activity and protein-binding effects.

Iron and copper ions, in their unbound form, may lead to the generation of reactive oxygen species via Haber-Weiss and/or Fenton reactions. In addition, it has been shown that copper ions can irreversibly and non-specifically bind to thiol groups in proteins. This non-specific binding property has not been fully addressed for iron ions. Thus, the present study compares both the pro-oxidant and the non-specific binding properties of Fe(3+) and Cu(2+), using rat liver cytosol and microsomes as biological systems. Our data show that, in the absence of proteins, Cu(2+)/ascorbate elicited more oxygen consumption than Fe(3+)/ascorbate under identical conditions. Presence of cytosolic and microsomal protein, however, differentially altered oxygen consumption patterns. In addition, Cu(2+)/ascorbate increased microsomal lipid peroxidation and decreased cytosolic and microsomal content of thiol groups more efficiently than Fe(3+)/ascorbate. Finally, Fe(3+)/ascorbate and Cu(2+)/ascorbate inhibited in different ways cytosolic and microsomal glutathione S-transferase (GST) activities, which are differentially sensitive to oxidants. Moreover, in the absence of ascorbate, only Cu(2+) decreased the content of cytosolic and microsomal thiol groups and inhibited cytosolic and microsomal GST activities. Catechin partially prevented the damage to thiol groups elicited by Fe(3+)/ascorbate and Cu(2+)/ascorbate but not by Cu(2+) alone. N-Acetylcysteine completely prevented the damage elicited by Cu(2+)/ascorbate, Fe(3+)/ascorbate and Cu(2+) alone. N-Acetylcysteine also completely reversed the damage to thiol groups elicited by Fe(3+)/ascorbate, partially reversed that of Cu(2+)/ascorbate but failed to reverse the damage promoted by Cu(2+) alone. Our data are discussed in terms to the potential damage that the accumulation of iron and copper ions can promote in biological systems.