Effects of L-arginine on impaired blood fluidity after high-intensity exercise: An in vitro evaluation.

BACKGROUND: Exercise-induced impairment of blood fluidity is considered to be associated with thrombosis development. However, the effects of L-arginine on blood fluidity after exercise remain unclear. OBJECTIVE: We investigated the mechanisms of impaired blood fluidity after high-intensity exercise, and examined whether L-arginine improves exercise-induced blood fluidity impairment in vitro. METHODS: Ten healthy male participants performed 15 minutes of ergometer exercise at 70% of their peak oxygen uptake levels. Blood samples were obtained before and after exercise. L-arginine and NG-monomethyl-L-arginine acetate (L-NMMA)-a nitric oxide (NO) synthase inhibitor-were added to the post-exercise blood samples. Using Kikuchi's microchannel method, we measured the blood passage time, percentage of obstructed microchannels, and the number of adherent white blood cells (WBCs) on the microchannel terrace. RESULTS: Exercise increased the hematocrit levels. The blood passage times, percentage of obstructed microchannels, and the number of adherent WBCs on the microchannel terrace increased after exercise; however, they decreased in a dose-dependent manner after the addition of L-arginine. L-NMMA inhibited the L-arginine-induced decrease in blood passage time. CONCLUSIONS: High-intensity exercise impairs blood fluidity by inducing hemoconcentration along with increasing platelet aggregation and WBC adhesion. The L-arginine-NO pathway improves blood fluidity impairment after high-intensity exercise in vitro.

Twenty-four-hour ambulatory oximetry monitoring in a patient with idiopathic pulmonary fibrosis for assisting in the discharge instruction on activities of daily living: a case report.

[Purpose] Patients with idiopathic pulmonary fibrosis (IPF) often develop remarkable exercise-induced hypoxemia and are hospitalized for management. The pre-discharge management of activities of daily living (ADL) should determine the amount of exercise-induced hypoxemia permitted during daily activities and inform concrete instructions based on these results. This clinical report aimed to promote 24-hour ambulatory oximetry monitoring in a patient with IPF to guide the pre-discharge management of ADL. [Participant and Methods] Our patient was a 67-year-old male with IPF. He was hospitalized and scheduled to be discharged after introduction of home oxygen therapy. Prior to discharge, we conducted a 24-hour ambulatory oximetry monitoring in the patient's home. We administered instructions on ADL based on these results. Furthermore, 1 day after discharge, we monitored his oxygen saturation level during ADL in his home. [Results] During the pre-discharge monitoring, the patient experienced hypoxemia during bathing, with a minimum oxygen saturation (SpO2) level of 87% and SpO2 level of <90% for 14.3% of the time. The patient was instructed on bathing by a physical therapist before discharge; this led to decreased desaturation, as the patient's SpO2 was <90% for 7.7% of the time. [Conclusion] Twenty-four-hour ambulatory oximetry monitoring is effective in guiding the pre-discharge management of ADL in the home with home oxygen therapy for patients with IPF.

L-cysteine improves blood fluidity impaired by acetaldehyde: In vitro evaluation.

Blood fluidity is reportedly influenced by the volume and function of blood cells and plasma and is a predictor of primary cardiovascular events in patients with traditional cardiovascular risk factors. Heavy alcohol consumption was shown to be associated with a higher risk for cardiovascular diseases. Acetaldehyde (ACD), an oxidizing substance formed from ethanol, reportedly stimulates monocyte adhesion, causes abnormalities in the red blood cell (RBC) membrane, and decreases RBC deformability. In addition, it was reported that blood ACD levels are reduced in mice pretreated with L-cysteine. However, there are no studies on the effect of ACD and/or L-cysteine on blood fluidity. In the present study, we evaluated whether ACD impairs blood fluidity. In addition, the effect of L-cysteine on blood fluidity impaired by ACD was examined. Blood samples were obtained from 10 healthy, non-smoking, male volunteers (age: 23.4 ± 1.2 years, body mass index: 21.8 ± 2.6 kg/m2). ACD or ACD and L-cysteine were added to the blood samples before each experiment. We measured the passage time of 100 µL blood and RBC suspension using Kikuchi's microchannel method. Percentage of microchannel obstruction and the number of adherent white blood cells (WBCs) on microchannel terrace were counted. The blood passage time, percentage of microchannel obstruction, and numbers of adherent WBCs on the microchannel terrace increased after adding ACD in a concentration-dependent manner, whereas they decreased after adding ACD and L-cysteine in a L-cysteine concentration-dependent manner. No significant effects were observed in passage time for 100 µL RBC suspension after adding ACD and L-cysteine. This study suggested that blood fluidity impaired by ACD might improve after adding L-cysteine.

Posture and firmness changes in a pressure-relieving air mattress affect cough strength in elderly people with dysphagia.

Dysphagia is the major pathophysiologic mechanism leading to aspiration pneumonia in the elderly. Elderly people with dysphagia who show low levels of the cough peak flow (CPF) are at greater risk for aspiration pneumonia. It has been reported that CPF values were significantly lower in the "soft" versus "hard" mode of a pressure-relieving air mattress in healthy volunteers in a supine position. Parameters such as spinal curvature, however, were not evaluated in detail. In this study, we clarified whether the changes in posture associated with two different firmness levels of a pressure-relieving air mattress were associated with cough production and related factors in the elderly with dysphagia. The body sinking distance, pelvic tilt angle, and immersion of the lumbar spine were measured to evaluate changes in posture. Forty subjects met the study criteria for dysphagia. The "soft" mode showed significantly lower CPF values than the "hard" mode (soft 274.9 ± 107.2 L/min vs. hard 325.0 ± 99.5 L/min, MD 50.0 95%CI 33.1-66.9 P < 0.001). Values of forced vital capacity (FVC) and maximal inspiratory pressure (PImax) were significantly lower in the "soft" mode than in the "hard" mode (MD 0.10 95%CI 0.04-0.17, P = 0.002, MD 3.2 95%CI 0.9-5.5, P = 0.007, respectively). Although there was no significant difference between the two firmness levels, maximal expiratory pressure (PEmax) values also tended to be lower in the "soft" than in the "hard" mode, (MD 2.9 95%CI -0.6-6.3 P = 0.1). At both firmness levels, CPF values were significantly correlated with FVC, PImax, and PEmax. The difference in sinking distance in the anterior superior iliac spine was significantly larger than that in the lesser tubercle of the humerus and patella. Additionally, in the soft mode, the pelvic tilt angle and contact area around the lumbar spine were significantly larger than those observed in the "hard" mode. Parameters associated with the production of cough, including inspiratory muscle strength, lung volume, and ultimately CPF, may be affected by immersion of the lumbar spine and curvature of the spine that results from the "soft" mode in elderly patients with dysphagia.