Clinical significance of blood brain natriuretic peptide level measurement in the detection of heart disease in untreated outpatients: comparison of electrocardiography, chest radiography and echocardiography.

The aim of present study was to compare the predictive characteristics and cost-benefit of measuring the concentration of blood brain natriuretic peptide (BNP), compared with electrocardiography (ECG), chest radiography and echocardiography, as a diagnostic test for heart disease. The study group comprised 130 untreated patients who had symptoms suggestive of heart disease. According to the results of additional examinations and follow-up checks, 86 patients were diagnosed as having heart disease and 44 patients were judged free of heart disease. Positive findings in each test suggestive of heart disease were checked in accordance with criteria, and the number of positive and negative cases for each test was calculated. The predictive characteristics, such as specificity, sensitivity, accuracy, positive and negative predictive values, of each test and the cost-benefit value were calculated and analyzed statistically. The sensitivity, specificity and accuracy of blood BNP and echocardiography were significantly greater than those of ECG and chest radiography. Echocardiography had a significantly lower cost-benefit value compared with measuring blood BNP concentration. Thus, the blood BNP concentration had significantly higher predictive characteristics than ECG and chest radiography, and a cost-benefit value significantly greater than that of echocardiography.     

Aotake: A modified stepping exercise as a useful means of improving lower‐extremity functional fitness in older adults

Aim: Poor functional fitness of the lower extremities is a potentially modifiable risk factor for falls. This study compared the Aotake stepping exercise, a unique indoor program, to walking and examined improvements in lower‐extremity functional fitness. Methods: We non‐randomly assigned 36 community‐dwelling older adults (age 67.3 ± 3.7 years) to either an Aotake stepping exercise group (group A, n = 19) or a walking group (group W, n = 17). During the 10‐week regimen, the members of each group participated in either a 45‐min Aotake or walking exercise session twice a week. Each session for group A consisted mainly of stepping activities on Aotake equipment (L42 × W10 × H3 cm); the equipment was made of plastic and had a bumpy surface to stimulate the soles of the feet. Results: Attendance rates were 91.1 ± 5.6% for group A and 89.7 ± 9.4% for group W. anova revealed improvements in leg strength and power (measured by isometric leg extension and chair stands), motor processing (measured by stepping with both feet and whole‐body reaction time) and locomotion (measured by walking around two cones and a 10‐m walk); the analysis revealed no group‐by‐time interactions. There was particular improvement (effect size = 1.18) in the chair stand measure in group A. However, the balance measures remained unchanged. Conclusion: Aotake stepping exercise may be just as effective as walking for improving lower‐extremity functional fitness. The current study, however, was a non‐randomized trial with a small sample size; further investigations would be warranted. Geriatr Gerontol Int 2010 ; 10: 244–250.     

Novel biological activity of the region (106-126) on human prion sequence

We report that the synthetic peptide Prp106-126 (KTNMKHMAGAAAAGAVVGGLG-COOH) and the reversed peptide Prp126-106 (GLGGVVAGAAAAGAMHKMNTK-COOH) of human prion (hPrp) can express the decarboxylase activity for oxaloacetate in the presence of trifluoroethanol, similar to that of Oxaldie 1 (LAKLLKALAKLLKK-CONH2) reported previously. The degree of the relative activity of Prp106-126 and Prp126-106 to Oxaldie 1 is 0.47 and 0.21, respectively. Based on this experimental result, we applied the informational system method (ISM) developed by Veljkovic et al. to the amino acid sequence of Prp106-126 and Prp126-106 to extract a common factor. The same spectra were obtained, indicating that the same periodicity may be conserved on their sequences, as a necessary factor for expressing the same biological activity, irrespective of the orientation of the primary sequence.     

Keratinocyte ATP release assay for testing skin-irritating potentials of structurally diverse chemicals

Irritant dermatitis represents innate inflammatory responses to toxic chemicals. We have reported recently that ATP released from chemically injured keratinocytes may serve as a causative mediator for irritant dermatitis. In this study, we examined whether ATP release from keratinocytes would serve as a reliable readout for predicting skin irritating potentials of structurally diverse compounds. A vast majority (19/20) of the tested compounds, i.e., strong and weak irritant chemicals selected from the literature, induced rapid (<10 min) and significant (P<0.05) ATP release from Pam 212 keratinocytes. Two compounds caused no detectable skin inflammation in our standard mouse model, documenting relatively high sensitivity (false negative rate of 0/18) and specificity (false positive rate of 1/20) of our ATP release assay. Selected compounds, primarily those containing phenol residues or hydrophobic hydrocarbon chains, triggered rapid (<10 min) and robust leakage of a fluorescence probe from liposomes, suggesting that lipid bilayers serve as one, but not the only, target moiety on keratinocytes. Not only do our data support the pathogenic role for keratinocyte-derived ATP in irritant dermatitis, they also form the basis for a formal validation study to evaluate the utility of the keratinocyte-based in vitro assay in screening environmental and industrial chemicals.     

Differential response of the membrane systems involved in excitation–contraction coupling to early and later postnatal denervation in rat skeletal muscle

We compared the morphological features of the membrane systems involved in excitation–contraction (E–C) coupling during early postnatal development stages in rat skeletal muscles (tibialis anterior) denervated either at birth or 7 days after birth. Four obvious structural changes are observed in the arrangement of the transverse (T) tubule network and the disposition of triads following early postnatal denervation: (1) an increase in the longitudinal segments of the T tubule network, (2) changes in the direction and disposition of triads, (3) the appearance of caveolae clusters, (4) the appearance of pentads and heptads (i.e. a close apposition of two or three T tubule elements with three or four elements of terminal cisternae of sarcoplasmic reticulum). The increased presence of longitudinal T tubules parallels the loss of cross striations, and this in turn is due to misalignment of the myofibrils. The clusters of caveolae appear almost exclusively in muscle fibres denervated at birth, and pentads and heptads are more frequently observed in muscles denervated at 7 days. The differential growth of muscle fibres in response to denervation leads to the formation of abnormal membrane systems involved in the E–C coupling with very unique morphological features, which differ from the case of denervation in adult muscle fibres.