Doxorubicin cardiotoxicity: diastolic cardiac myocyte dysfunction as a result of impaired calcium handling in isolated cardiac myocytes

We examined intracellular calcium transients of isolated single cardiac myocytes from rats with doxorubicin (DOX)-induced cardiomyopathy with simultaneous measurement of cell motion. DOX was administered i.p. to Sprague-Dawley rats at 2.5 mg/kg once a week for 10 weeks. Field-stimulated calcium transients and simultaneous cell motion in single myocytes were measured in the presence or absence of isoproterenol using fura-2/AM. Histopathologic examination revealed slight changes. The time courses of both calcium transients and cell motion were significantly prolonged by DOX. There was a slight but not significant reduction in parameters of contractility in both calcium transients and cell motion. The beta-adrenoceptor responsiveness of both calcium transients and cell motion was not significantly impaired compared with the controls. Our data indicated that, despite the slight histologic changes in the heart in DOX-induced cardiomyopathy, impaired sequestration of intracellular free calcium ions in individual myocytes may be one factor leading to diastolic dysfunction. Monitoring of diastolic function is important to detect early cardiotoxicity caused by DOX.     

Determination of citric acid and its decomposed products in edible oils by gas liquid chromatography

A quantitative gas liquid chromatographic (GLC) method for four organic acids-citric, aconitic, itaconic, and citraconic acids-in refined oils and fats was developed. After the organic acids are extracted with water from soybean oils, the extract is esterified with n-butanol and an aliquot of the ester is subjected to GLC on a temperature-programmed 10% DEGS column equipped with a flame ionization detector. At 20 and 30 ppm levels, recoveries of the acids from the oil varied from 95 to 100% except for itaconic acid. Citric acid content in commercial edible oils in Japan was from trace to 16 ppm. However, aconitic, itaconic, and citraconic acids were not detected.     

Effects of theophylline, verapamil, and mannitol on oxygen consumption of ischemic rat kidneys

This study was designed to determine, through the measurement of oxygen consumption (QO2), whether pretreatment and posttreatment with theophylline, verapamil, and mannitol provide protection from damage in the cortex and medulla of rat kidneys subjected to 60 and 120 minutes of ischemia. QO2 levels in both tissues were examined 1 day after each ischemia. After 60 minutes of ischemia, pretreatment with theophylline and verapamil primarily provided protection from ischemic change in cortical QO2. Pretreatment with mannitol provided protection from both cortical and medullary changes in QO2, but posttreatment with mannitol only protected cortical QO2. After 120 minutes of ischemia, only pretreatment with verapamil was effective in protecting cortical QO2 from ischemic injury. These observations demonstrate that theophylline, verapamil, and mannitol are effective in protecting renal QO2 in the ischemic kidney. During this study, it became clear that there were differences in the effectiveness of theophylline and verapamil on QO2 in the ischemic kidney between pretreatment and posttreatment, and also between the cortex and the medulla.     

Increase of hematocrit in experimental renal hypertension and its reversal

The electroencephalograms of 82 infants (between 27 and 37 weeks of conceptional age) recorded during the neonatal period were analyzed and compared with the ultimate clinical evolution. Three groups of infants were identified according to their neurological state at 3 years of age or older: group A: normal (34 infants), group B: minor neurological sequellae (13 infants) and group C: major neurological sequellae (17 infants). A fourth group (group D: 18 infants) died during the neonatal period. The E.E.Gs were classified as: normal, questionably abnormal, moderately abnormal or grossly abnormal. The analysis revealed that E.E.Gs classified as grossly abnormal, were found only in groups B, C and D. Serial E.E.Gs were of more value in distinguishing these groups. Only infants in groups C and D (with I exceptional case in group B) had E.E.Gs which remained abnormal for several weeks or which deteriorated during the neonatal period. This study shows the prognostic value of the E.E.G. recorded during the neonatal period, particularly serial recordings obtained during and after a period of clinical deterioration. A detailed statistical analysis of the E.E.Gs is in progress.     

Enhancement in thermoelectric power factor of M/T/N and M/Bi/M/Bi/M (M and N = Cu or Ni) composite devices welded with T = Bi or Bi<Subscript>0.88</Subscript>Sb<Subscript>0.12</Subscript> alloy

The resultant thermoelectric power factors P of M/T/N and M/Bi/M/Bi/M (M and N = Cu or Ni) devices welded with T = Bi or Bi_0.88Sb_0.12 alloy were measured at 298 K and compared with P values calculated as a function of x by treating these devices as an electrical and thermal circuit, where x is the ratio of thickness of Bi or Bi-Sb alloy to the interval between two thermocouples. Consequently, the Seebeck coefficients of M/T/N devices were enhanced significantly in the middle range from x = 0.3 to 0.8, and the observed P values have a local maximum at small x below x = 0.35. The x-dependence of P values of M/T/N devices was found to be explained well by the simple model proposed here when an enhancement factor in and some reduction in thermal conductivity of pure metal were taken into the calculation. As a whole, however, the observed P values of double-layered M/Bi/M/Bi/M devices are lower than those of single-layered M/Bi/M, so that the macroscopic multi-layering of thermoelectric materials has no effect on the enhancement in P. The maximum P (= 22.1 mW/K²m) of Cu/Bi-Sb/Cu is 1.5 times larger than that of Cu/Bi/Cu and reached 3.6 times as large as the mean value of 5.7 and 6.6 mW/K²m of the high-performance bulk p- and n-type bismuth-telluride compounds.     

Proposals for wastewater treatment by applying flocculating activity of cross-linked poly-gamma-glutamic acid

Cross-linked poly-gamma-glutamic acid (C-L gamma-PGA) markedly purified polluted water collected from rivers and ponds by flocculation and precipitation. This effect of C-L gamma-PGA occasionally required pretreatment with polyaluminum chloride (PAC). Components of polluted water in rivers or ponds are generally thought to be clay minerals, microorganisms and chemical compounds. In this study, the flocculating activities of C-L gamma-PGA against suspensions of bentonite, diatomaceous earth, Escherichia coli and Mycrocystis aeruginosa, and against solutions of crystal violet and bisphenol A were investigated. The mode of action of C-L gamma-PGA is thought to be based on electrostatic interaction between flocculants, C-L gamma-PGA and PAC, and the surface of polluted water components, which may lead to neutralization of the zeta-potential of those components.     

Important role of blood rheology in atherosclerosis of patients with hemodialysis

Concerning a role of blood rheology for atherosclerosis in patients with hemodialysis (HD), little data are available. It may be due to the fact that the method for evaluating rheologic properties of circulating blood has been limited. We examined blood rheology in 118 HD patients by using microchannel array flow analyzer that makes it possible to directly observe the flow of blood cell elements through the microchannel. Transit time (T(B)) of heparinized whole blood through slit pores (7 x 30 microm) was used as an index of rheology and related with various inflammatory biomarkers such as high-sensitive CRP (hsCRP), monocyte chemotactic protein-1, osteopontin, or fibrinogen (Fg). Moreover, as a surrogate marker of atherosclerosis, carotid intima-media thickness (IMT) and aortic stiffness evaluated by brachial-ankle pulse-wave velocity (baPWV) were studied. In HD patients, T(B) had strong positive correlations with hsCRP (r = 0.427; p < 0.00001), Fg (r = 0.452; p < 0.00001), and osteopontin (r = 0.227; p < 0.0134). Further, T(B) was significantly well correlated with IMT (r = 0.400; p < 0.0001) and PWV (r = 0.470; p < 0.0001). Multivariate regression analysis showed that baPWV, IMT, Fg, hematocrit, white blood cell count, and CRP were chosen as significant explanatory factors for T(B.) These results suggest that blood rheology may play an important role for atherosclerosis in patients with HD.     

New porous carbon materials,Woodceramics: Development and fundamental properties

Woodceramics are new porous carbon materials obtained by carbonizing wood or woody material impregnated with thermosetting resin such as phenol resin in a vacuum furnace. During the carbonizing process, thermosetting resin changes into glassy carbon, which has superior corrosion resistance and mechanical strength, reinforces the material and suppresses the fissures and warps (caused by the porous structure specific to wood) that develop during thermoforming. The dimension, weight decrease rate, and electrical characteristics depend on the thermoforming temperature. The manufacturing method of Woodceramics is introduced in this paper and various industrial uses, such as electromagnetic shields, are discussed.     

Surface temperature of Pd/C catalyst under microwave irradiation in dechlorination process of PCBs

In recent years, a new effective method of processing for polychlorinated biphenyls (PCBs) has been developed: It enables PCBs to become harmless by dechlorinating them using a 2.45 GHz microwave (MW). Compared with conventional thermal heating, MW processing hardly produces any harmful byproduct materials, and has high reaction velocity. To investigate such promotion of chemical reaction by MW irradiation, the surface temperature of the catalyst is measured by an infrared camera just after the irradiation by MW. It is recognized that there are some heated regions on the catalyst and the temperature is not uniform. It is natural to say that chemical reaction is promoted well on such a heated region. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.