Long-term follow-up after aortic valve replacement with a small aortic prosthesis.

Although aortic valve replacement (AVR) is an effective treatment for patients with aortic valvular disease, the implantation of a small aortic prosthesis may result in residual left ventricular outflow stenosis and transvalvular gradient. In this study, the outcome in the long-term period of patients treated with a small aortic prosthesis was analyzed retrospectively. Twenty-four patients with AVR were divided into two groups, group A and group B. Group A consisted of 16 patients with 21 mm-sized prosthetic valves, and group B consisted of 8 patients with 19 or 16 mm-sized prosthetic valves. There were no significant differences in preoperative cardiac function or operative procedure in the two groups. The mean follow-up period (months) was 55.0 in group A and 51.3 in group B. RESULTS: One patient died of cerebral infarction in group A. There were no significant differences in cardiothoracic ratio (CTR), left ventricular ejection fraction (LVEF), and left ventricular mass index (LVMI) between the two groups. Postoperative physical activity according to the New York Heart Association (NYHA) classification showed no significant differences in the two groups. Despite using a small prostheses for AVR, the postoperative course was good in the long-term period, although careful follow-up is necessary.     

Kindling of the visual cortex in cats: comparison with amygdaloid kindling

Kindling of the primary visual cortex (VC) was compared with that of the amygdala in cats. VC kindling was basically similar to kindling of the amygdala in that daily electrical stimulation can lead to the development of a generalized convulsion in most subjects, a growth of afterdischarges in their configuration and duration, and a reduction of the afterdischarge threshold. The kindling response of the VC differed from that of the amygdala in a number of respects, i.e., a high afterdischarge threshold, a different pattern of behavioral seizure development, an abrupt growth of electroclinical seizures coincident with the onset of a generalized convulsion, an intersubject variability in seizure susceptibility, and a marked seizure instability. In VC kindling the afterdischarge propagation into the amygdala was not observed until the generalized convulsion developed, and the early involvement of afterdischarge was seen in the pulvinar, lateral geniculate body, and superior colliculus. These data suggest that a neural mechanism different from amygdaloid kindling may participate in VC kindling, and that the subcortical structures of the visual system are involved in the preferential pathway for a seizure generalization from the VC.     

Die Entwicklungsgeschichte des Kopfskelettes des Cryptobranchus japonicus

Ohne ZusammenfassungMit 26 Textabbildungen.     

The effects of Na movement on surgical myocardial protection: the role of the Na+-H+ exchange system and Na-channel in the development of ischemia and reperfusion injury.

OBJECTIVES: We investigated whether the Na+-H+ exchange inhibitor, HOE642 (Hoe), and/or the Na channel blocker, mexiletine (Mex), enhance a cardioprotective effect on St. Thomas' Hospital cardioplegic solution (STS) to clarify the mechanism by which intracellular Na+ is accumulated after cardioplegic arrest. MATERIALS AND METHODS: Isolated working rat hearts were perfused with Krebs-Henseleit bicarbonate buffer (KHBB). The hearts were then arrested with STS and subjected to normothermic global ischemia (30 min). This was followed by Langendorff reperfusion (15 min) and then a working reperfusion (20 min). In study A, we added Hoe (5, 10, and 20 microM), Mex (70 microM), or a combination of Hoe (20 microM) and Mex (70 microM), to STS. In study B, we added Hoe (20 microM), Mex (70 microM), or a combination of Hoe (20 microM) and Mex (70 microM) to KHBB during the first 3 min of Langendorff reperfusion. RESULTS: In study A, the addition of Hoe (10 and 20 microM) to STS showed a significantly greater postischemic recovery of cardiac output compared to the control group [63.1+/-5.7% (10 microM), 62.7+/-4.7% (20 microM), and 55.5+/-4.6% (control), respectively]. The postischemic recovery of cardiac output was significantly greater in the group of the combined addition (Hoe and Mex) to STS than that in the control, 20 microM Hoe, 70 microM Mex groups [70.3+/-3.7 (Hoe and Mex), 55.5+/-4.6% (control), 62.7+/-4.7% (Hoe 20 microM), and 60.2+/-4.7% (Mex 70 microM), respectively]. The myocardial water content in the postischemic period was 565.1+/-29.1, 525.8+/-2.9, 509.4+/-19.6, and 532.2+/-20.1; it was 497.3+/-9.1 mL/100 g dry weight in the control; and 10 microM Hoe, 20 microM Hoe, and 70 microM Mex in the combined use groups. In study B, there was no significant difference in the postischemic recovery of cardiac output in all experimental groups. CONCLUSION: The combined use of the Na+-H+ exchange inhibitor and Na+ channel blocker during cardioplegia may achieve a superior cardioprotective effect on myocardial damage because of ischemia and reperfusion.     

Studies on isolated smooth muscle cells. IX. Application of papain for isolation of single smooth muscle cells from guinea-pig taenia coli

To prepare single smooth muscle cells from the taenia coli of guinea pig, the application of papain to the enzymatic solution was examined under two conditions: 1) the isolation in a modified Tyrode solution (containing 0.18 mM Ca2+: 0.18 mM Ca2+-Tyrode solution) and 2) the isolation in a high-K+ Tyrode solution (Na+ was replaced by K+, and Ca2+ was not added: high-K+ Tyrode solution). The presence of papain during collagenase digestion reduced contamination of broken cells and cell debris. In the case of the high-K+ Tyrode solution, papain increased the yield of single cells significantly. The cells were contracted in a dose-dependent manner by Ca2+ in the high-K+ Tyrode solution and by carbachol in 0.18 mM Ca2+-Tyrode solution; furthermore, the contractions were antagonized by verapamil and atropine, respectively. Treatment with papain did not affect cell sensitivity to the stimulants. Therefore, our results suggest that the addition of papain is useful for the isolation of single cells to investigate the physiological and pharmacological characteristics of smooth muscle.