No abstract

The purpose of this study was to determine the effect of passive leg cycle exercise (PLE) on cardiovascular and respiratory responses in people with spinal cord injuries (PSCI). Eight PSCI with lesions from T8 to L1 and five control subjects (CS) performed PLE at pedalling frequencies of 20 or 40 rpm for 7 min at room temperature of about 25 degrees C. We measured, at rest and during PLE, the pulmonary ventilation (VE), oxygen uptake (VO2), cardiac output (Q), stroke volume (SV), heart rate (HR) and arterial blood pressure, as well as the skin blood flow (SBF) in the lower limb after PLE. An increase in pedalling frequency promoted an increase in VE and VO2 in both groups. Compared with the CS, the PSCI showed significantly smaller increases in VO2 (P < 0.05). The Qc was significantly elevated during PLE at 20 and 40 rpm in CS, and at 40 rpm in PSCI (P < 0.05). In CS, it resulted from increases in both SV and HR, whereas in PSCI, it was contributed to by a greater increase in SV without a rise in HR. In CS, the increase in pedalling frequency promoted the increases in SV and HR and consequently in Qc. In PSCI, however, the values remained constant irrespective of pedalling frequency. The arterial blood pressure and SBF in the lower limbs were unchanged by PLE in both groups. These results would suggest that passive leg exercise promotes venous return from the paralyzed lower limbs in PSCI.

In a hyperbaric chamber, a living mature specimen of Nautilus pompilius withstood a hydrostatic pressure of 8.05 MPa (80.5 kg/cm2) equivalent to 785 m deep in the sea. Thereafter it was killed instantly by implosion of the shell. Before implosion, the animal reacted physiologically to increasing pressure. Therefore, the depth of 785 m can be assigned the depth limit of N. pompilius. The result bears on critical interpretations on the paleoecology and paleobiology of extinct nautiloids and ammonoids with similar shells.

No abstract

Renal ischemia-reperfusion (I/R) injury is unavoidable in kidney transplantation (KTx) and frequently influences both short-and long-term allograft survival. Carbon monoxide (CO) has attracted attention as a medical gas with anti-inflammatory and anti-apoptotic effects. We investigated a new strategy for organ preservation using ex vivo application of high-pressure CO in an experimental rat KTx model. We preserved kidney grafts using a high-pressure chamber filled with mixed gases composed of CO and O 2 . We found that cold I/R injury resulted in progressive deterioration of renal graft function in University of Wisconsin solution, whereas CO significantly improved renal function. We confirmed that CO decreased oxidative stress and mRNA expression of proinflammatory cytokines and inhibited tubular apoptosis in the early phases. Western blot analysis demonstrated that CO increased phosphatidylinositol-3 kinase and phosphorylation of Akt and p38 mitogen-activated protein kinase. Furthermore, CO significantly alleviated tubular injury scores and suppressed the development of interstitial fibrosis at 100 days after KTx. Thus, high-pressure mixed CO and O 2 gases successfully preserved rat kidney grafts for 24 h by protecting tubular epithelial cells from apoptosis and inhibiting inflammation.

The purposes of the present study were to examine the response of the skin blood flux (SBF) in the paralyzed lower limbs of persons with spinal cord injury (PSCI) and to clarify the relationship between the SBF and core temperature during prolonged arm exercise. Eight male PSCI with lesions from T6 to L5 and six male control subjects (CS) participated in this study. The subjects rested for 60 min and then performed arm-cranking exercise at 20 W for 30 min at 25 degrees C. The tympanic membrane temperature (Tty) and SBF in the anterior thigh (SBFT) and in the posterior calf (SBFC) were continuously measured throughout the experiment. The SBFC did not change in either PSCI or CS during the experiment. The SBFT in four PSCI with high lesions (T6 to T12), remained unchanged during exercise. The SBFT in the other four PSCI with low lesions (T12 to L5, delta SBFT+) began to elevate markedly when the Tty exceeded a threshold temperature of 36.69 degrees C. The pattern of increase of SBFT in delta SBFT+ was similar to that in CS, although onset of the increase in SBFT was delayed and the peak of SBFT during exercise was significantly lower in comparison with the CS. We consider that these differences between the delta SBFT+ and CS were largely attributable to the lower Tty in the former group, which took a prolonged time to reach the threshold of 36.69 degrees C.

The purpose of this study was to examine whether arm cranking exercise induces changes in skin blood flow in the paralyzed lower limbs of people with injuries to the spinal cord (PISC). Ten PISC with lesions located between Th5 and L5 and six control subjects performed arm cranking exercise for 6 min at three intensities, 10, 30 and 50 W, at a room temperature of 25 degrees C. Oxygen uptake (Vo2) and heart rate (HR) were measured for the last 2 min of each exercise period. The skin blood flow at the anterior thigh (BFsk,t) was continuously monitored using laser Doppler flowmetry for the whole 6-min period and for the first 10 min of recovery following exercise. During exercise, the PISC showed lower Vo2 and greater HR than the control subjects. No increase in BFsk,t was found in six of the PISC with lesions at or above Th12, irrespective of the exercise intensity. On the other hand, in PISC with lesions at L1 or below, BFsk,t increased significantly (P < 0.05) with an increase in Vo2 and HR, although the BFsk,t at a given Vo2 and HR was lower than that in the control subjects. These results would suggest that arm exercise can promote the blood circulation in the skin of the lower limbs if the injury level is below L1.

It is currently said that CO has anti-inflammatory and antiapoptosis effects and it has attracted attention as a medical gas. We used CO for rat hearts and conducted a preservation experiment. We isolated rat hearts, placed them into a specially made chamber, filled the chamber with a gas mixture of PCO (4,000 hPa) and PO2 (3,000 hPa), and preserved the hearts in a refrigerator at 4°C for 48 h. We then performed a heterotrophic transplantation on the neck of each recipient rat and resuscitated the preserved hearts. We herein report our findings.