Effects of low-intensity, elastic band resistance exercise combined with blood flow restriction on muscle activation.

We examined the effects of blood flow-restricted, low-intensity resistance exercise (termed kaatsu) using an elastic band for resistance on muscle activation. Nine men performed triceps extension and biceps flexion exercises (four sets respectively) using an elastic band for resistance with blood flow restriction (BFR) or CON (unrestricted blood flow). During a BFR session, subjects wore pressure cuffs inflated to 170-260 mmHg on the proximal region of both arms. Surface electromyography (EMG) was recorded from the triceps brachii and biceps brachii muscles, and mean integrated EMG (iEMG) was analyzed. Blood lactate concentration was obtained before (Pre) and immediately after two exercises (Post). During triceps extension and biceps flexion exercises, muscle activation increased progressively (P < 0.05) under BFR (46% and 69%, respectively) but not under CON (12% and 23%, respectively). Blood lactate concentration at Post was higher (P < 0.05) under BFR than under CON (3.6 and 2.1 mmol/L, respectively). Blood lactate concentration at Post was significantly correlated with increased iEMG in both triceps extension (r = 0.65, P < 0.01) and biceps flexion exercises (r = 0.52, P < 0.05). We conclude that kaatsu training using elastic bands for resistance enhances muscle activation and may be an effective method to promote muscle hypertrophy in older adults or patients with a low level of activity.

Troglitazone inhibits voltage-dependent calcium currents in guinea pig cardiac myocytes.

BACKGROUND: It has been suggested that intracellular Ca2+ overload in cardiac myocytes leads to the development of diabetic cardiomyopathy. Troglitazone, an insulin-sensitizing agent, is a promising therapeutic agent for diabetes and has been shown to prevent diabetes-induced myocardial changes. To elucidate the underlying mechanism of troglitazone action on cardiac myocytes, the effects of troglitazone on voltage-dependent Ca2+ currents were examined and compared with classic Ca2+ antagonists (verapamil and nifedipine). METHODS AND RESULTS: Whole-cell voltage-clamp techniques were applied in single guinea pig atrial myocytes. Under control conditions with CsCl internal solution, the voltage-dependent Ca2+ currents consisted of both T-type (ICa,T) and L-type (ICa,L) Ca2+ currents. Troglitazone effectively reduced the amplitude of ICa,L in a concentration-dependent manner. Troglitazone also suppressed ICa,T, but the effect of troglitazone on ICa,T was less potent than that on ICa,L. The current-voltage relationships for ICa,L and the reversal potential for ICa,L were not altered by troglitazone. The half-maximal inhibitory concentration of troglitazone on ICa,L measured at a holding potential of -40 mV was 6.3 micromol/L, and 30 micromol/L troglitazone almost completely inhibited ICa,L. Troglitazone 10 micromol/L did not affect the time courses for inactivation of ICa,L and inhibited ICa,L mainly in a use-independent fashion, without shifting the voltage-dependency of inactivation. This effect was different from those of verapamil and nifedipine. Troglitazone also reduced isoproterenol- or cAMP-enhanced ICa,L. CONCLUSIONS: These results demonstrate that troglitazone inhibits voltage-dependent Ca2+ currents (T-type and L-type) and then antagonizes the effects of isoproterenol in cardiac myocytes, thus possibly playing a role in preventing diabetes-induced intracellular Ca2+ overload and subsequent myocardial changes.

Troglitazone and pioglitazone attenuate agonist-dependent Ca2+ mobilization and cell proliferation in vascular smooth muscle cells.

1. The effects of troglitazone and pioglitazone on agonist-induced Ca2+ mobilization and cell proliferation were studied using fluorescent Ca2+ indicator fura-2 AM and incorporation of [3H]-thymidine in rat aortic smooth muscle cells. The patch clamp techniques were also employed. 2. Vasopressin and platelet-derived growth factor-BB (PDGF) caused a transient elevation in [Ca2+]i by Ca2+ mobilization from intracellular stores, followed by a sustained rise due to Ca2+ entry. Nicardipine partly inhibited the sustained phase, but La3+ completely abolished it. 3. Troglitazone and pioglitazone did not significantly affect the transient rise elicited by these agonists, but preferentially inhibited the sustained phase of [Ca2+]i. 4. Under voltage clamp conditions, troglitazone and pioglitazone inhibited voltage-dependent L-type Ca2+ current (ICa.L). They also inhibited nonselective cation channels (Icat) elicited by vasopressin in a concentration-dependent manner. The half maximal inhibitory concentrations of troglitazone on ICa.L and Icat were 4.6 and 5.7 microM, respectively. On the other hand, nifedipine and nicardipine did not inhibit Icat. 5. Vasopressin and PDGF increased incorporation of [3H]-thymidine, and nifedipine and nicardipine partly suppressed it. However, the inhibitory effects of La3+ and exclusion of extracellular Ca2+ were more potent than the Ca2+ blocking agents. Troglitazone and pioglitazone also inhibited it concentration-dependently. 6. These results suggest that troglitazone and pioglitazone preferentially inhibited agonist (vasopressin and PDGF)-induced Ca2+ entry and proliferation in rat vascular smooth muscle cells, where the inhibitory effects of thiazolidinediones on ICa.L and Icat might be partly involved. Thus, thiazolidinediones may exert hypotensive and antiatherosclerotic effects.

[Homebound elderly in a Japanese community: related factors and change of mobility].

The aim of this study was to identify the prevalence of homebound elderly (defined as people whose daily activities were limited to their home) and factors related to it among 300 community elderly residents aged 60 and over in Yamagata city. In 1995, the baseline survey was performed and the follow-up survey was conducted one year later. Subjects were divided into two groups according to the extent of their daily activities: the non-homebound group (defined as people whose daily activities extended into their community) and the homebound group. The main results were as follows; 1. The prevalence of homebound elderly was 7.7% in 1995. 2. Chi-square test or t test was performed to examine the relationship between homebound and various factors. Significant factors were age, history of hypertension, history of mental disease, incompetence of ADLs (walking, eating, toileting, bathing, dressing), interpersonal dependency, subjective health, 'ikigai' (meaningfulness of life), life style (cooking, cleaning, reading newspaper or magazine, watching TV, exercise, associate with friend) and TMIG (Tokyo Metropolitan Institute of Gerontology) index of competence. The present study reveals that daily activities in community elderly residents is related to not only physical factors but also psychosocial factors. Using the significant variables in univariate analysis, multiple logistic regression analysis controlling for age was performed. Significant factors for homebound were incompetence of ADLs (walking, toileting), subjective health and TMIG index of competence. 3. Three out of 214 non-homebound elderly persons in 1995 changed to homebound in 1996.

[Global life satisfaction and its related factors in community elderly residents].

This study was aimed at identifying the distribution of global life satisfaction as measured by Visual Analogue Scale (VAS) and factors related to it in 531 community elderly residents aged 75-80 years. Subjects were divided into two groups according to the extent of their daily activities, which has been emphasized as an important health index for the elderly: the outdoor-activity group (defined as people whose daily activities extended into their community) and the indoor-activity group (defined as people whose daily activities was limited to inside their home). The distribution of global life satisfaction and related factors were compared between the two groups. For independent variables, daily behaviors were classified into five categories and examined for how they related to global life satisfaction. The results obtained were as follows: Global life satisfaction showed a bimodal distribution in both groups tending to be lower in the indoor-activity group than in the outdoor-activity group. Most of the indoor-activity group indicated low or moderate life satisfaction. The extent of their daily activities was thus related to global life satisfaction. The strongest direct factor relating to global life satisfaction was self-rated health for the outdoor-activity group. Some of their daily behaviors also related to it and these significant daily behaviors differed by sex. Only self-rated health was related to global life satisfaction in the indoor-activity group. The results indicate that, when compared to other factors, daily activity in community elderly residents is crucial to increasing their global life satisfaction, and therefore efforts to enlarge subjects' daily activities are also required.

[Midterm achievement and problems of all municipal health and welfare plans for the elderly in Yamagata Prefecture].

PURPOSE: This study was made for providing information in the preparation of Social Welfare Systems in municipalities. METHODS: Based on seven official reports by Yamagata Prefecture, quantitative data on health and welfare services were analyzed. We investigated the midterm achievement and problems of a Municipal Health and Welfare Plan for the Elderly in all 44 municipalities by mail survey (response rate 100%). The questionnaire included the progress situation of the plan, the existence of an assessment organization, and the characteristics of the plan. RESULTS: Both health service and welfare service achieved targets level to a degree. Concerning the progress situation, "The midterm achievement is not satisfactory" for 65.9% (29 municipalities). The main reasons were "budgets" (93.1%, 27 municipalities) and "lack of manpower" (75.9%, 22 municipalities) all of which indicates "lack of home helpers". 58.6% of all 44 municipalities were reconsidering the plan. In assessment organization existed in 31.8% (14 municipalities) of all municipalities. CONCLUSION: It is necessary that analysis should consider not only use of quantitative data but also qualitative one. The major problems found are that community characteristics were not reflected and the opinion of inhabitants were not considered.

[Compliance concerning external protectors for hip fractures among the institutionalized elderly in Japan].

An external protector (EHP) which was developed in Europe to protect the femoral neck from direct impact on falling is available but has not been examined sufficiently in Japan. In order to explore the compliance of use of the EHP among the institutionalized elderly with in case of hip fracture who are at high risk of falling, we conducted the four-week intervention study using two types of a EHP. The subjects of a study consisted of 10 elderly people (2 men, 8 women) with a mean age 85.7 living in nursing home in a village. Informed consent was obtained from all participants. At the end of the study, rate of subjects who wore EHP was relatively high for the Finnish EHP (Safety Pants) group compared to the Danish EHP (Hip Protector) group. There were no significant differences between variables in age, sex, fall experience during the previous year, history of diseases etc. The reasons for dropout were first: difficult in wearing EHP and accompanying delay in toilet, secondly: taking much time to wear, thirdly: a sense of incongruity, too small or too tight'. If the EHP is redesigned to suit Japanese elderly, the compliance might increase. Thorough explanation to institutionalized elderly who may have cognitive impairment, physical problems, or both, is required.

Eicosapentaenoic acid inhibits voltage-gated sodium channels and invasiveness in prostate cancer cells.

BACKGROUND AND PURPOSE: The voltage-gated Na(+) channels (Na(v)) and their corresponding current (I(Na)) are involved in several cellular processes, crucial to metastasis of cancer cells. We investigated the effects of eicosapentaenoic (EPA), an omega-3 polyunsaturated fatty acid, on I(Na) and metastatic functions (cell proliferation, endocytosis and invasion) in human and rat prostate cancer cell lines (PC-3 and Mat-LyLu cells). EXPERIMENTAL APPROACH: The whole-cell voltage clamp technique and conventional/quantitative real-time reverse transcriptase polymerase chain reaction analysis were used. The presence of Na(v) proteins was shown by immunohistochemical methods. Alterations in the fatty acid composition of phospholipids after treatment with EPA and metastatic functions were also examined. KEY RESULTS: A transient inward Na(+) current (I(Na)), highly sensitive to tetrodotoxin, and Na(V) proteins were found in these cells. Expression of Na(V)1.6 and Na(V)1.7 transcripts (SCN8A and SCN9A) was predominant in PC-3 cells, while Na(V)1.7 transcript (SCN9A) was the major component in Mat-LyLu cells. Tetrodotoxin or synthetic small interfering RNA targeted for SCN8A and SCN9A inhibited metastatic functions (endocytosis and invasion), but failed to inhibit proliferation in PC-3 cells. Exposure to EPA produced a rapid and concentration-dependent suppression of I(Na). In cells chronically treated (up to 72h) with EPA, the EPA content of cell lipids increased time-dependently, while arachidonic acid content decreased. Treatment of PC-3 cells with EPA decreased levels of mRNA for SCN9A and SCN8A, cell proliferation, invasion and endocytosis. CONCLUSION AND IMPLICATIONS: Treatment with EPA inhibited I(Na) directly and also indirectly, by down-regulation of Na(v) mRNA expression in prostate cancer cells, thus inhibiting their metastatic potential.

The prevalence and psychosocial characteristics of the frail elderly in Japan: a community-based study.

There is insufficient epidemiological data about frail elders in Japan. Few studies concerning the relationship between psychosocial characteristics and frailty exist in the literature. The purpose of this study was to assess the prevalence and to explore the characteristics of the frail elderly in a community of Japan by cross-sectional and case-control studies. Data were collected from a total of 2,310 non-institutionalized persons aged 65 years or older, by mail survey and interview. We defined frailty as a precursor of disability. The prevalence of frail elders was estimated at 6.1%. After controlling for age and gender, multiple logistic regression analyses disclosed that frail elders displayed significantly higher emotional reliance on another person, worsening self-efficacy, fair or poor subjective health, and poor functional ability than independent elders, and significantly higher self-efficacy than bedridden elders. The most noticeable finding in this study was the significant association of psychosocial factors with frailty among the community-dwelling elderly. Based on our study results, we suggest that when controlling physical variables, psychosocial variables might strongly affect the frail status among elderly persons.

Type II alveolar epithelial cells in lung express receptor for advanced glycation end products (RAGE) gene.

Messenger RNA of receptor for advanced glycation end products (RAGE) is abundantly expressed in the lung. However, cell types expressing RAGE mRNA in the lung have not been identified. In order to elucidate the function of RAGE in pulmonary tissue, we have identified a cell type expressing RAGE mRNA by in situ hybridization and compared its expression level of RAGE mRNA by RNA blot analysis of isolated cells. In situ hybridization revealed that RAGE mRNA was intensely and specifically visualized in alveolar epithelial type II (AT-II) cells, and weakly in alveolar macrophages. The expression of RAGE mRNA in the primary culture of AT-II cells was at a high level, but that in alveolar macrophages isolated from alveolar lavage was under the level of detection by RNA blot analysis. These results showed that RAGE mRNA is specifically expressed in AT-II cells, and suggested that RAGE makes a substantial contribution to the function of AT-II cells in the lung.

Factors relating to place of death of Japanese people from a small town in a rural area.

The objective of our retrospective study was to clarify factors relating to place of death of Japanese people from a small town in a rural area who had been bedridden for at least one week before dying. The caregivers of subjects aged 40 and above who died during a three-year period were surveyed by trained interviewers. Of 352 subjects who died, 312 caregivers responded and agreed to a face-to-face interview. A total of 213 subjects were considered as an eligible sample. The main outcome measures were odds ratios for death at home in relation to age, pain, cause of death, and home visit service. One hundred and two people died at home, while 112 people died in a hospital. Multivariate logistic regression analysis showed that the probability of home death increased with age of the bedridden, lack of pain during the bedridden period, not having cancer as a cause of death, having senility as a cause of death, and receiving regular home visits by a Public Health Nurse. In conclusion, expansion of the home visit programs by Public Health Nurses may enable people to die at home as they so desire. Further prospective research is needed to explore the association between the attitude toward terminal care and the place of death.