The purpose of this study was to investigate the relationship between Achilles tendon properties and foot strike patterns in long-distance runners. Forty-one highly trained male long-distance runners participated in this study. Elongation of the Achilles tendon and aponeurosis of the medial gastrocnemius muscle were measured using ultrasonography, while the participants performed ramp isometric plantar flexion up to the voluntary maximum. The relationship between the estimated muscle force and tendon elongation during the ascending phase was fit to a linear regression, the slope of which was defined as stiffness. In addition, the cross-sectional area of the Achilles tendon was measured using ultrasonography. Foot strike patterns (forefoot, midfoot and rearfoot) during running were determined at submaximal velocity (18 km · h(-1)) on a treadmill. The number of each foot strike runner was 12 for the forefoot (29.3%), 12 for the midfoot (29.3%) and 17 for the rearfoot (41.5%). No significant differences were observed in the variables measured for the Achilles tendon among the three groups. These results suggested that the foot strike pattern during running did not affect the morphological or mechanical properties of the Achilles tendon in long-distance runners.

An 85-year-old man underwent endoscopic submucosal dissection for a large superficial esophageal epithelial neoplasm, which required removal of 95% of the circumference of the esophageal mucosa. Steroids were given orally to prevent esophageal stricture starting on day 3 postoperatively. In the 6th week of steroid treatment, he developed high fever without other symptoms. Chest computed tomography revealed a nodular lesion in the lung. Sputum sample showed Gram-positive, branching, filamentous bacteria, and a diagnosis of nocardiosis was suspected. Brain magnetic resonance imaging revealed multiple focal lesions which indicated dissemination of nocardiosis. Trimethoprim-sulfamethoxazole was immediately started, which led to the disappearance of pulmonary and cerebral nocardiosis with alleviation of fever. Recently, oral steroid treatment has been widely used for the prevention of esophageal stricture. However, the present case indicates the risk of life-threatening infection and the importance of close monitoring of this treatment.

The gene amplification plays a critical role in the malignant transformation of mammalian cells. The most widespread method for amplifying a target gene in cell culture is the use of methotrexate (Mtx) treatment to amplify dihydrofolate reductase (Dhfr). Whereas, we found that a plasmid bearing both a mammalian origin of replication (initiation region; IR) and a matrix attachment region (MAR) was spontaneously amplified in mammalian cells. In this study, we attempted to uncover the underlying mechanism by which the IR/MAR sequence might accelerate Mtx induced Dhfr amplification. The plasmid containing the IR/MAR was extrachromosomally amplified, and then integrated at multiple chromosomal locations within individual cells, increasing the likelihood that the plasmid might be inserted into a chromosomal environment that permits high expression and further amplification. Efficient amplification of this plasmid alleviated the genotoxicity of Mtx. Clone-based cytogenetic and sequence analysis revealed that the plasmid was amplified in a chromosomal context by breakage-fusion-bridge cycles operating either at the plasmid repeat or at the flanking fragile site activated by Mtx. This mechanism explains how a circular molecule bearing IR/MAR sequences of chromosomal origin might be amplified under replication stress, and also provides insight into gene amplification in human cancer.

The effects of muscarinic and beta-adrenergic agonists on Cl(-) currents in acinar cells were investigated to clarify their role in the regulation of fluid secretion in rat perfused submandibular glands. Additions of isoproterenol (IPR) at 10(-8) to 10(-6) M and 8-(4-chlorophenylthio)-cyclic AMP (CPT-cAMP) at 10(-3) M to the perfusate suppressed carbachol (CCh; 10(-6) M)-induced fluid secretion. IPR and CPT-cAMP also diminished CCh-induced oscillatory Cl(-) current and increased CCh-stimulated non-oscillatory Cl(-) current. Propranolol blocked the effect of IPR on fluid secretion. IPR did not modulate the CCh-induced increase in intracellular concentration of calcium ions and intracellular pH in isolated cells. Propranolol blocked IPR-induced changes in Cl(- )currents, while propranolol itself increased CCh-induced K(+) current and reduced CCh-induced oscillatory Cl(-) current. Increasing external osmolarity with 50 mM sucrose abolished IPR-enhanced non-oscillatory Cl(-) current. Neither CCh-induced oscillatory Cl(-) current nor IPR-induced suppression of the oscillatory Cl(-) current was influenced by the hypertonicity. Perfusion of the gland with the hypertonic solution did not affect the IPR-induced suppression of fluid secretion. These results suggest that IPR induces the suppression of CCh-induced oscillatory Cl(-) current and potentiation of the non-oscillatory Cl(-) current via an increase in cyclic AMP level, and that suppression of the oscillatory Cl(-) current by IPR may contribute to the inhibition of fluid secretion from submandibular glands.

Chest compression is performed mainly through flexion and extension of the hip joint while kneeling on the floor and through the elbow and shoulder joints while standing in a moving ambulance. Therefore, the low quality of chest compression during ambulance transportation may be attributable to an altered technique of performing the procedure.