Objective: When performing knee extension using a leg extension machine, the lower limb is pushed back in the direction in which knee flexion occurs in response to the freefall of the weight after maximal knee extension. Therefore, eccentric contractions of the knee extensors are needed, which may lead to cumulative fatigue of the extensors, consequently reducing the reliability of the knee extensor torque values. This study aimed to determine the relationship between joint torque and angular velocity in one repetition maximum (1RM) measurement for knee extension using a leg extension machine with and without a modification to prevent counter-rotation.
Methods: Twenty-one healthy adult men (mean age: 27.7±5.4 years) participated in the study. A leg extension machine was modified to prevent counter-rotation due to the freefall of weights. The subjects performed knee extension using the modified leg extension machine, and the joint torque and angular velocity were calculated using two-dimensional analysis. A regression equation between these two factors was created to estimate the maximal isometric torque.
Results: Both the joint torque and angular velocity tended to increase after modification of the leg extension machine, although these differences were not significant. Similarly, there were no significant post-modification changes in the estimated maximal isometric torque.
Conclusions: Our results showed that the joint torque, angular velocity, and estimated maximal isometric torque remained unchanged after machine modification; thus, the modified leg extension machine may make it possible to produce the knee extensor torque more safely in 1RM measurement.
Objectives: We investigated and compared clinicopathologic features and subtype distribution of invasive breast cancer among women <40 and ≥40 years of age.
Methods: We retrospectively compared clinicopathologic characteristics and subtype distribution of invasive breast cancer in women <40 and ≥40 years of age, in a cohort of 1,130 patients. Subtypes included luminal A (positive for hormone receptors [HR]—estrogen receptor [ER] and/or progesterone receptor [PR]—and negative for human epidermal growth factor receptor 2 [HER2] with low Ki67), luminal B (HER2–) (HR+/HER2–/Ki67High), luminal B (HER2+) (HR+/HER2+), HER2-overexpressing (HR–/HER2+), and triple negative (ER–/PR–/HER2–).
Results: Breast cancers in younger women had unfavorable clinicopathologic characteristics, including larger tumors and more frequent node involvement. Subtypes among the 1,130 tumors were luminal A: 36.4%, luminal B (HER2–): 35.0%, luminal B (HER2+): 7.5%, HER2-overexpressing: 7.1%, and triple negative: 14.0%. The age groups significantly differed in subtype distribution (P<0.001). Luminal A subtype was more common in the older group (38.5%) than the younger group (16.2%), and luminal B (HER2–) was more common in the younger group (52.2%) than in the older group (33.2%; P<0.001).
Conclusions: Breast cancers in women younger than 40 years have unfavorable clinicopathologic characteristics and are more likely to be luminal B (HER2–) and less likely to be luminal A than breast cancers in older women.
Objectives: The objective of this study was to identify the role of reactive oxygen species (ROS) generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, in inositol hexaphosphate (IP6)-induced metabolic disruption in human leukemia PLB-985 cells.
Methods: PLB-985 and X chromosome linked gp91-phox gene knockout (X-CGD) cells were treated with 5, 10, or 20 mM IP6 for 24 to 72 h. Cell growth was assayed using a highly water-soluble tetrazolium salt. The rate of apoptotic and necrotic cell death was determined with an Annexin V-fluorescein isothiocyanate/propidium iodide kit. The expression of CD11b as a marker of monocytic property and of LC3 as an autophagy marker was tested, using flow cytometry combined with fluorescent antibodies.
Results: Treatment with 5 and 10 mM IP6 for 24 h was found to suppress the growth of both cell lines, though the effect was more dramatic in PLB-985 cells. After 6-h treatment with 20 mM IP6, the necrosis rate of PLB-985 cells was significantly greater than that of X-CGD cells. Further, after 72-h treatment with 10 mM IP6, CD11b expression was observed in PLB-985 cells but inhibited in X-CGD cells. Autophagy monitoring after 6-h treatment with 10 mM IP6 revealed that LC3 expression was suppressed in PLB-985 cells, whereas it was somewhat increased in X-CGD cells.
Conclusions: Our results suggest that NADPH oxidase activation mediates IP6-induced metabolic disruption associated with necrosis, differentiation, cell growth, and autophagy in PLB-985 cells.
Objectives: Nasal high-flow (NHF) therapy provides continuous positive airway pressure (CPAP), flushes the anatomical dead space, and improves mucociliary clearance. CPAP is usually applied at a flow rate at or above an established threshold value with the mouth closed because it is hard to maintain it with an open mouth. We conducted a prospective study to validate our hypothesis that CPAP can be applied with the mouth open through a surgical face mask.
Methods: We inserted 12-Fr nasogastric tubes through the noses of 18 healthy individuals and fixed each tube within the pharynx to monitor the intrapharyngeal pressure. We monitored the pressure during the following two conditions: NHF oxygen with the mouth open (condition O) and NHF oxygen with the mouth open and wearing a surgical face mask (condition OM). We set the NHF rate at 40 L/min and the oxygen concentration at 21%, under all conditions. We measured the intrapharyngeal pressure five times during each inspiration and expiration, and calculated mean values.
Results: The mean expiratory intrapharyngeal pressure (median [interquartile range]) increased significantly from the baseline during conditions O (2.08 [1.58–4.02] cm H2O) and OM (3.35 [2.72–3.79] cm H2O). In addition, there was a significant difference in pressure between conditions O and OM (p=0.0263, Wilcoxon signed-rank test).
Conclusions: In our healthy volunteers, the intrapharyngeal pressures increased during expiration with an open mouth while wearing a surgical face mask.
A 63-year-old woman was admitted to our hospital with a right lower abdominal mass and general fatigue. Preoperative examination suggested a large ovarian tumor or cecal carcinoma. However, her intraoperative diagnosis was colon cancer; we therefore performed an ileocecal resection with oophorectomy. The tumor was pathologically diagnosed as adenosquamous carcinoma T4bN1M-stage IIIa. We administrated CapeOX adjuvant chemotherapy for 6 months. Adenosquamous carcinoma is extremely rare, at around 0.1% of all colorectal cancers, and usually has a poor prognosis. The patient is still alive without recurrence after 84 post-operative months, even with later developments of metachronous early colorectal cancer and breast cancer. We herein report a rare case of cecal ASC with good prognosis.