Tsutomu Inamizu

Alteration in length of telomeric repeats in lung cancer

We investigated the relationship between telomere length and various characteristics of tumor cells in 46 lung cancer specimens (40 primary lesions and six metastatic lesions). Three variant patterns of telomere length were observed in 16 cases (34.8%): reduction in 13 cases, elongation in two cases, and convergence in one case. These variant patterns were frequently observed in small cell carcinomas, in metastatic lesions, and in cases which possessed the S-type allele of the L-myc gene. All three cases with telomere elongation or convergence were associated with a poor prognosis. This is compatible with the previous report suggesting that telomerase activity may be an indicator of immortality in vitro. In adenocarcinoma, telomere reduction or elongation was also observed in the early stages with a low percentage of cells in the S-phase, while in cases with other histologic types, these changes were observed only in late stage, in metastatic lesions, or in cancerous tissues with a high percentage of cells in the S-phase. Although the reduction of telomere length in these tissues may be a result of many cell divisions, it may represent another stage of carcinogenesis in early-stage adenocarcinoma.

Determinants of the daily rhythm of blood fluidity

Background Numerous processes in the living body exhibit daily rhythmicity. In this study, we characterized a daily rhythm of blood fluidity and identified its determinants. Methods The subjects were nine young males. We measured the physiological parameters and performed hematological and biochemical analyses. We repeated the measurements six times during the day at 7:30 (just after getting up and before breakfast), 10:00, 13:30 (after lunch), 16:30, 19:30 (after dinner), and 21:30. The subjects performed sedentary work all day, and the contents and time of the meals were uniform. Investigation of blood rheology was based on Kikuchis microchannel method. Results Blood passage time varied significantly with time of day. Stepwise regression analysis was used to determine the significant factors affecting blood passage time. Body temperature, heartbeat, hematocrit, white blood cell and total cholesterol were significant determinants of blood passage time. Conclusion We confirmed that blood fluidity has a daily rhythm. In addition, we found that the determinants of blood fluidity included physiological parameters such as body temperature and heartbeat, hematological parameters such as hematocrit, and white blood cell and total cholesterol.

Pulmonary Oxidative Stress Is Induced by Maximal Exercise in Young Cigarette Smokers

INTRODUCTION Oxidative stress is induced by both cigarette smoking and acute exercise. It has also been reported that exercise can induce plasma oxidative stress in young cigarette smokers. However, no previous report has demonstrated that exercise induces pulmonary oxidative stress in cigarette smokers. The aim of this study was to determine whether pulmonary oxidative stress is induced by maximal exercise in cigarette smokers as measured by reactive oxygen species generation and total antioxidant content. METHODS Fifteen male smokers (mean age: 25.9 ± 2.9 years) and 18 male nonsmokers (mean age: 24.2 ± 4.3 years) participated in this study. Hydrogen peroxide (H(2)O(2)) concentration and biological antioxidant potential (BAP) in exhaled breath condensate (EBC) were measured at baseline and after maximal exercise in the Wingate anaerobic test. RESULTS A significant interaction of group by time was observed for EBC H2O2 concentration (p = .015). After exercise, EBC H(2)O(2) concentrations were significantly increased in the smoking group (p = .030) but not in the nonsmoking group. There were no significant changes in EBC BAP in either group. CONCLUSIONS These findings indicate that in cigarette smokers, maximal exercise induces pulmonary oxidative stress, which may lead to oxidative damage in the lungs.

The neural influence on the occurrence of locomotor–respiratory coordination

This study focused on the neurogenic mechanisms of coordination between locomotor and respiratory rhythms. The aim of the present study was to investigate the influence of peripheral neurogenic drive from moving limbs, and the level of consciousness, on locomotor-respiratory coordination. Subjects performed movement for 20 min in a supine position using a bicycle ergometer. The movement comprised three types of leg movements: active (loadless) movement, passive movement while awake and passive movement during sleep. We found no difference between active and passive movement in the degree of coordination. However, the degree of coordination during sleep was significantly lower than that while awake (p<0.05). We conclude that peripheral neurogenic drive from moving limbs is able to generate locomotor-respiratory coordination, and that the level of consciousness may influence the degree of coordination.

Plasma oxidative stress is induced by single‐sprint anaerobic exercise in young cigarette smokers

Cigarette smoking increases oxidative stress, which is a risk factor for several diseases. Smoking has also been reported to enhance plasma oxidative stress during strenuous exercise. However, no prior study has examined the changes in plasma oxidative stress after single‐sprint anaerobic exercise in cigarette smokers. The purpose of this study was to investigate these changes in young cigarette smokers by measuring reactive oxygen species generation and total antioxidant content. Participants were 15 male smokers (mean age: 25·9 ± 2·9 years) and 18 male non‐smokers (mean age: 24·2 ± 4·3 years). Hydroperoxide concentration and biological antioxidant potential (BAP) in plasma were measured at baseline and after the Wingate anaerobic test. A significant interaction between group and time was observed for plasma hydroperoxide concentration (P = 0·037). Plasma hydroperoxide concentration was significantly increased after exercise in both smokers and non‐smokers (P = 0·001 and <0·001, respectively). However, no significant interaction was observed between groups by time on plasma BAP (P = 0·574), and a main effect of time was observed (P<0·001). Plasma BAP was significantly increased after exercise in both groups (both, P<0·001). These findings indicate that plasma oxidative stress is higher in cigarette smokers than in non‐smokers after single‐sprint anaerobic exercise, which may increase the risk of oxidative damage.

Phase-dependent modulation of corticospinal excitability during the observation of the initial phase of gait

Abstract This study was undertaken to identify the temporal characteristics of corticospinal excitability of tibialis anterior muscle during the observation of the initial phase of gait. For this purpose, using transcranial magnetic stimulation, we recorded motor evoked potentials (MEPs) during the observation of the second step of an actor’s first three steps of gait initiation with (complex gait) or without (normal gait) an obstacle and unstable surface. The results demonstrate that (1) MEPs during the observation of the initial phase of normal gait were significantly increased only at early swing phase, but not other phases (mid-swing, heel contact, mid-stance, and heel off) and (2) MEPs during the observation of the initial phase of complex gait were significantly increased at early swing and also at mid-swing and heel contact phases. These findings provide the first evidence that corticospinal excitability during the observation of gait, especially the initial phase, is modulated in phase- and motor-demanded-dependent manners.

Duplication polymorphism within the third intron of the p53 gene is a rare event in Japanese population

Duplication polymorphism within the third intron of the p53 gene is a rare event in Japanese population