[show abstract][hide abstract] ABSTRACT: No existing device for cardiopulmonary resuscitation (CPR) is designed to exploit both the "cardiac pump" and the "thoracic pump" effect simultaneously. The purpose of this study was to measure the haemodynamic effect of a new simultaneous sternothoracic cardiopulmonary resuscitation (SST-CPR) device that could compress the sternum and constrict the thoracic cavity simultaneously in a canine cardiac arrest model. After 4 min of ventricular fibrillation, 24 mongrel dogs were randomized to receive standard CPR (n=12) or SST-CPR (n=12). SST-CPR generated a new pattern of the aortic pressure curve presumed to be the result of both sternal compression and thoracic constriction. SST-CPR resulted in significantly higher mean arterial pressure than standard CPR (68.9+/-16.1 vs. 30.5+/-10.0 mmHg, P<0.01). SST-CPR generated higher coronary perfusion pressure than standard CPR (47.0+/-11.4 vs. 17.3+/-8.9 mmHg, P<0.01). End tidal CO(2) tension was also higher during SST-CPR than standard CPR (11.6+/-6.1 vs. 2.17+/-3.3 mmHg, P<0.01). In this preliminary animal model study, simultaneous sternothoracic cardiopulmonary resuscitation generated better haemodynamic effects than standard, closed chest cardiopulmonary resuscitation.
[show abstract][hide abstract] ABSTRACT: An analytical system for a one-step immunoassay has been constructed using the concept of immunochromatography. The system employed two different antibodies that bound distinct epitopes of an analyte molecule: an antibody labeled with a signal generator (e.g., colloidal gold), which was placed in the dry state at a predetermined site on a glass-fiber membrane, and another antibody immobilized on the surface of a nitrocellulose membrane. Three membranes, one with the tracer, one with immobilized antibody, and a cellulose membrane as the absorbent of medium (in a sequence from the bottom), were attached to a plastic film and cut into strips. Aqueous medium containing analyte absorbed from the bottom end of the immunostrip dissolved the labeled antibody, and the antigen-antibody binding complex formed was transported into the next nitrocellulose membrane by the flow caused by capillary action. The complex subsequently reacted with the immobilized antibody, which generated a signal in proportion to the analyte concentration. The convective mass transfer of the immunoreactant to the binding partner allowed the assay to be performed with no handling of reagents. The reaction, however, was carried out under nonequilibrium conditions, which resulted in decreased sensitivity as compared with assays performed in an equilibrium mode (e.g., ELISA). To minimize such sacrifice, major factors that control system performance were identified and the system was then devised under optimal conditions.
[show abstract][hide abstract] ABSTRACT: [formula: see text] cis- and trans-Oxazoline-5-carboxylates were synthesized efficiently from isopropyl trans-cinnamate utilizing the Sharpless AA reaction. trans-Oxazoline was much more reactive than the cis-isomer toward ring opening reactions. From ab initio molecular calculations, the cis-isomer was predicted to be less reactive than the trans-isomer by 2.7 kcal/mol. Both syn and anti acetylthio esters and anti diamino esters were synthesized from these cis- and trans-oxazoline-5-carboxylates.
[show abstract][hide abstract] ABSTRACT: It is well established that ginseng saponin has positive influences on various neural diseases, but little is known about its electrophysiological effects in the central nervous system. In this study, we examined the electrophysiological effects of ginseng saponin in rat hippocampal slices. Total saponin from ginseng root reduced the slope of fEPSPs (field excitatory postsynaptic potentials) in the CA1 area in a dose-dependent manner (9.1 +/-5.4%, 48.4+/-12.1%, and 60.5+/-15.3% at 10, 50, and 100 microg/ml, respectively), which was reversed within 10 min of washout. Seven different ginsenosides resulted in varied degrees of fEPSPs reduction. The rank order of reduction was Rb1, Rg1 >Rg2, Rh1, Rc>Rd, Re within a range of 5-64% reduction. No difference in the suppressive action between protopanaxadiol (Rb1, Rc, Rd) and protopanaxatriol (Rg1, Rg2, Re, Rh1) saponins was shown; the slope of fEPSPs was reduced by 38% and 40% on average, respectively. The possible role of gamma-aminobutyric acid (GABA(A)) receptor in the suppressive action of ginseng saponins was tested using whole cell patch recording in acutely isolated hippocampal neurons. Ginsenosides did not induce chloride current nor modified GABA-induced current. Also, the suppressive effect of ginsenosides on fEPSPs was still observed in the presence of the GABA(A) receptor antagonist, bicuculline methiodide 50 microM. These results suggest that the suppressive effect is not attributable to regulation of GABA(A) receptor activation.
[show abstract][hide abstract] ABSTRACT: The signaling mechanism of tamoxifen (TAM)-induced apoptosis was investigated in HepG2 human hepatoblastoma cells which do not express the estrogen receptor (ER). TAM induced cytotoxicity and DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. TAM increased the intracellular concentration of Ca2+. This effect was completely inhibited by the extracellular Ca2+ chelation with EGTA. TAM also induced a Mn2+ influx, indicating that TAM activated Ca2+ influx pathways. This action of TAM was significantly inhibited by flufenamic acid (FA), a known non-selective cation channel blocker. Quantitative analysis of apoptosis by flow cytometry revealed that treatment with either FA or BAPTA, an intracellular Ca2+ chelator, significantly inhibited TAM-induced apoptosis. These results suggest that intracellular Ca2+ signals may play a central role in the mechanism of the TAM-induced apoptotic cell death in ER-negative HepG2 cells.
Cancer Letters 01/2000; 147(1-2):115-23. · 4.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: In cross-sectional fashion, we recorded the maximal combined response and 30-Hz flicker responses in 178 adult diabetics and 40 normal controls according to the recommendations of the International Society of Clinical Electrophysiology of Vision. The oscillatory potentials were extracted from the maximal combined response by high-pass filtering. The clear media and attached retina were criteria for inclusion in this study. The data were statistically analyzed with the expectation that this procedure may provide a new feature that could have some clinical significance. Timing delays occurred more frequently than amplitude reductions in the maximal combined response and flicker responses, while amplitude reductions were more common in the first and second oscillatory potentials. The hypernormal b-wave amplitude was rare. The summed amplitude of the oscillatory potentials was highly correlated with the total power of the oscillatory potentials (the frequency domain). A reduction of the second oscillatory potential amplitude was more common than a reduction of the summed amplitude or total power. The electroretinographic component that demonstrates retinal dysfunction in the earlier stage may be a valuable indicator. In the early stage, a delay in the a-wave time and a reduction in the second oscillatory potential amplitude were the most frequent abnormalities: analysis of variance demonstrated that the summed amplitude of the oscillatory potentials and second oscillatory potential amplitude and time were the most sensitive measures of the diabetic retina. Hence, the second oscillatory potential amplitude may be the most sensitive and valuable indicator representing a quantitative measure of overall retinal dysfunction.