Differential effects of isoproterenol on the canine atrial action potential in the presence of carbachol or nicorandil

In canine atrial muscles, carbachol and nicorandil hyperpolarized the resting membrane potential and shortened the action potential duration. In the presence of carbachol or nicorandil, isoproterenol further hyperpolarized the resting membrane potential and shortened the action potential duration. Isoproterenol significantly increased the plateau duration in the presence of nicorandil, but further abbreviated it in the presence of carbachol. This increase in the plateau duration by isoproterenol in the presence of nicorandil probably reflects the increase in the slow inward current.     

Fumonisins as a possible contributory risk factor for primary liver cancer: A 3-year study of corn harvested in Haimen, China, by HPLC and ELISA

Employing HPLC fluorometry, gas-liquid chromatography (GLC) and a novel enzymelinked immunosorbent assay (ELISA) based on a monoclonal antibody, 40 corn samples, each collected in 1993 from agricultural stocks for human consumption in Haimen (Jiangsu County) and Penlai (Shandong Province), high- and low-risk areas for primary liver cancer (PLC) in China, respectively, were analysed for fumonisins (FBs), aflatoxins (AFs) and trichothecenes. Levels and positive rates of FBs and deoxynivalenol (DON) were significantly higher in Haimen than in Penlai. ELISA of the 40 corn samples harvested in the two areas in 1994 revealed that FB contamination levels and rates in these areas were comparable to those observed in 1993 in Haimen. ELISA analysis of 1993 and 1994 products revealed a wide occurrence of AFB₁ but the positive rates as well as levels were not significantly different between these areas. ELISA of the same sample number of corn harvested in 1995 revealed that FB contamination in Haimen was significantly higher than in Penlai. These 3-yearly surveys of corn samples (240 in total) demonstrated that corn harvested in Haimen was highly contaminated with FBs and that the contamination level, as well as positive rate in 1993 and 1995, were 10–50-fold higher than those in Penlai, suggesting FBs as a risk factor for promotion of PLC in endemic areas, along with the trichothecene DON. Co-contamination with AFs, potent hepatocarcinogens, was assumed to play an important role in the initiation of hepatocarcinogenesis.     

Cyclosporine overcomes cold preservation/reperfusion injury of liver graft: Chemokine release and liver ultrastructure

There is a growing body of evidence that the cytokine, tumor necrosis factor-α (TNF-ga), plays an important role in the development of hepatic ischemia/reperfusion injury. We found that the immunosuppressants, cyclosporine-A (CsA), azathioprine, and FK506, have protective effects on such injury. The purpose of the present study was to elucidate mechanisms involved in these beneficial effects of the immunosuppressant, CsA, on liver injury following cold preservation and transplantation, with special reference to the suppression of TNF-α release. Rat livers were stored in Euro-Collins solution (EC) at 4°C for 6h and orthotopically transplanted. The animals allotted to two groups: group A (untreated controls) and group B (CsA pretreatment of recipients). CsA (10 mg/kg, p.o.) was given for 3 consecutive days preoperatively. CsA pretreatment of the recipients significantly improved the 2-week survival rate (0/6 for group A, 3/6 for group B;P<0.05) and this was associated with a significant decrease in serum TNF-α levels 2h posttransplantation (group A, 69.8±15.7 pg/ml; group B, 22.8±6.8; mean±SEM;n=12 each;P<0.05) and amelioration of sinusoidal endothelial injury, assessed by electron microscopy. Plasma endotoxin levels following reperfusion of the grafts were not altered by the CsA therapy. Morphologically, CsA pretreatment of the recipients did not alter activation of Kupffer cells. CsA pretreatment of the recipient aids in preventing cold preservation/reperfusion injury of the liver graft, possibly by modulating effects of TNF-α.     

Hydrolysis of phenyl esters in cyclodextrin-polymer systems

The catalytic hydrolysis of phenyl esters in systems containing ß-cyclodextrin (ß-CD) and polyelectrolytes was investigated. Poly(methacrylic acid) was found to exhibit an inhibition effect on the hydrolysis, while poly(sodium styrenesulfonate) (NaPSS) shows a pronounced acceleration effect on the hydrolysis: the larger the molecular weight and the lower the degree of substitution, the greater is the acceleration effect. On the other hand, sodium ethylbenzenesulfonate and sodium dodecylbenzenesulfonate inhibit the reaction. The acceleration of the reaction in presence of NaPSS is attributed to the concentration of ß-CD and the substrate esters near to the chain of the macromolecule, through inclusion effects and hydrophobic interactions.     

Heterotopic ischemic pain attenuates somatosensory evoked potentials induced by electrical tooth stimulation: diffuse noxious inhibitory controls in the trigeminal nerve territory.

The purpose of this study was to determine whether the late component of somatosensory evoked potentials (SEP) induced by electrical tooth stimulation and pain intensity are inhibited by heterotopic ischemic stimulation. The tourniquet pressure with 50 mmHg greater than the individual's systolic pressure was applied to the left upper arm for 10 min as ischemic conditioning stimulation. The late component of SEP and visual analogue scale (VAS) were recorded at 4 times and both were significantly decreased when ischemic conditioning stimulation was applied. The maximum reductions in SEP amplitude and the VAS value were 26.1% and 21.2%, respectively, during ischemic conditioning stimulation. After-effect was observed 5 min after removal of the conditioning stimulation. The present study revealed that heterotopic ischemic stimulation attenuated the late component of SEP induced by electrical tooth stimulation, triggering diffuse noxious inhibitory controls (DNIC) and after-effects in the trigeminal nerve territory. It was also suggested that the DNIC effect differs, depending on the intensity, kind, and quality of the test and conditioning stimuli.     

Clinical effects of percutaneous cardiopulmonary support in severe heart failure: early results and analysis of complications.

Between January 1993 and December 2001, we employed percutaneous cardiopulmonary support (PCPS) in 35 patients. PCPS was used for postcardiotomy in 25 of these patients who could not be weaned from cardiopulmonary bypass (CPB) because of severe cardiogenic shock. In the other 10 patients, PCPS was used for a non-surgical disease. Twenty-nine patients (82.9%) were weaned from PCPS, and 28 (80.0%) survived. The other 7 patients (20.0%) died due to postoperative complications. The causes of death were multiple organ failure (MOF) due to wound bleeding, low cardiac output syndrome (LOS), myonephropathic metabolic syndrome (MNMS) with severe lower limbs ischemia, cerebrovascular accident (CVA), and sepsis. The first cause for the complications was postoperative sustained severe heart failure. To improve the survival rate, it was necessary to prevent bleeding and begin PCPS at an earlier stage.     

Adaptational changes in cone electroretinograms in man

Changes of amplitude and implicit time of human cone electroretinogram (ERG) were studied during dark adaptation and succeeding light adaptation. Dark-adapted cone ERG was isolated by subtracting scotopic blue response from matched scotopic red response. The former represented the rod-mediated b-wave, while the latter consisted of both rod-mediated b-wave and cone-mediated b-wave or x-wave. The b-wave amplitude of dark-adapted cone ERG remained unchanged during dark adaptation, while the implicit time increased systematically, reaching a plateau. Light-adapted cone ERG was obtained by red stimulus lights under a bright background light. The amplitude of light-adapted cone ERG was markedly suppressed through dark adaptation but it recovered gradually during light adaptation, reaching the base line level. The implicit time was unchanged during light adaptation.