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51.
The negative conduction effect of quinidine on each of the successive phases of the ventricular depolarization was investigated using an original noninvasive method: the spatial velocity electrocardiogram of the QRS complex (SVECG-QRS). We performed a randomized placebo-controlled trial in 10 healthy subjects with a single oral dose of quinidine (330 mg) or placebo. Electrocardiographic acquisition and processing (220 recordings for the complete trial) were performed using the Lyon vectorcardiographic program. For each SVECG-QRS curve, the position of seven specific points from A (onset of QRS) to G (end of QRS) were determined precisely. The six successive time intervals between these points (AB-FG) and five velocity values (B-F) were then calculated. The QRS complex was longer under quinidine than placebo (102.4 +/- 1.6 vs. 100.3 +/- 1.5 ms). The difference was at the periphery of statistical significance (p = 0.05), and this lack of statistical difference may be mainly due to the low serum levels of quinidine obtained at the peak of the concentration (1.46 +/- 0.4 mg/1). All six QRS time intervals were longer under quinidine, but only the BC interval was significantly different (9.3 +/- 1.1 vs. 18.8 +/- 1.1 ms; p < 0.05) suggesting a more pronounced negative conduction effect at the onset of ventricular depolarization. No significant modifications were observed for the velocity values. We conclude that (1) the negative conduction effect of quinidine is heterogeneous, but a further study with a higher dose of quinidine (concentration-dependent effect) is required to confirm this hypothesis and (2) the spatial velocity electrocardiogram of the QRS complex allows a detailed analysis of the ventricular conduction phases. The results of the measurement were found to be reproducible. This noninvasive tool could be used in clinical practice to assess effects of antiarrhythmic drugs on successive ventricular depolarization phases.  相似文献   
52.
PURPOSE OF STUDY: Interleukin-2 (IL-2) is a potent activator of lymphocytes, but its effectiveness as an anti-cancer agent is compromised by several adverse side effects including pulmonary edema. One explanation for the pulmonary toxicity of IL-2 is that activated lymphocytes directly induce the pulmonary vascular endothelium to become more leaky. METHODS: To test this hypothesis the number of total lymphocytes, gamma delta T cells, and CD2-positive cells (alpha beta T cells and natural killer cells) in peripheral blood and lung lymph of sheep were compared before and after IL-2 infusion. Hemodynamic and lymph dynamic changes were also evaluated. RESULTS: IL-2 decreased mean aortic pressure, increased cardiac output, lowered systemic vascular resistance, and doubled lung lymph flow (P < or = 0.05), but had no effect on plasma or lymph oncotic pressure. The lymph protein concentration and the lymph-to-plasma protein concentration ratio were not different after IL-2 infusion. IL-2 had no effect on the number of total lymphocytes, gamma delta T cells, or CD2-positive cells in the peripheral blood. In contrast, the number of total lymphocytes, gamma delta T cells, and CD2-positive cells in lung lymph decreased significantly (P < or = 0.05). CONCLUSIONS: The lymphocyte populations decreased more than could be explained by the increase in lymph flow, demonstrating that lung lymphocytes were not reduced simply by dilution. These results imply that the pulmonary edema associated with IL-2 is not caused by activated lymphocytes.  相似文献   
53.
Gas exchange function through the middle ear mucosa was assessed using nitrous oxide (N2O) in patients with otitis media with effusion (OME), as well as in normal ears during elective surgery for unrelated disorders. In all normal ears except one (n = 43), an increase in pressure was observed after N2O inhalation. In 42 of 84 ears with OME, a pressure increase was observed, but not in the remaining 42 ears (50%), indicating that the gas exchange function in these latter ears was impaired. In 21 of the 42 ears showing no middle ear pressure increase following N2O inhalation, the middle ear pressure was again monitored after myringotomy and aspiration of the effusion A pressure increase was found in 16 ears, indicating that the impairment in gas exchange function in ears with OME may be reversible in most cases. Computed tomography of the mastoid was examined preoperatively in 66 ears, with the presence or absence of a middle ear pressure change well correlated in 57 ears with the presence or absence of mastoid aeration.  相似文献   
54.
BACKGROUND: Major depressive disorder is often marked by repeated episodes of depression. We describe recovery from major depression across multiple mood episodes in patients with unipolar major depression at intake and examine the association of sociodemographic and clinical variables with duration of illness. METHODS: A cohort of 258 subjects treated for unipolar major depressive disorder was followed up prospectively for 10 years as part of the Collaborative Depression Study, a multicenter naturalistic study of the mood disorders. Diagnoses were made according to the Research Diagnostic Criteria, and the course of illness was assessed with the Longitudinal Interval Follow-up Evaluation. Survival analyses were used to calculate the duration of illness for the first 5 recurrent mood episodes after recovery from the index episode. RESULTS: Diagnosis remained unipolar major depressive disorder for 235 subjects (91%). The median duration of illness was 22 weeks for the first recurrent mood episode, 20 weeks for the second, 21 weeks for the third, and 19 weeks for the fourth and fifth recurrent mood episodes; the 95% confidence intervals were highly consistent. From one episode to the next, the proportion of subjects who recovered by any one time point was similar. For subjects with 2 or more recoveries, the consistency of duration of illness from one recovery to the next was low to moderate. None of the sociodemographic or clinical variables consistently predicted duration of illness. CONCLUSION: In this sample of patients treated at tertiary care centers for major depressive disorder, the duration of recurrent mood episodes was relatively uniform and averaged approximately 20 weeks.  相似文献   
55.
This paper introduces the Precise Rendering Method, which generates accurately anti-aliased and highlighted images from tessellated polygons. The Precise Rendering Method first solves the aliasing problems of hidden surface removal by using the Cross Scanline Algorithm. This algorithm can exactly calculate polygon areas projected onto each pixel by using horizontal and vertical scanlines. Aliasing artifacts in shading are then prevented by the Reflection Intergration Method, which analytically integrates the intensity of reflection in the solid angle defined by surface normals at vertices of the projected area. Several synthesized images are created to show the efficiency of the Precise Rendering Method.  相似文献   
56.
57.
A dc brushless motor is a kind of synchronous motor driven by an inverter and requires sensors to detect the rotor position. As one of the methods, the induced voltages of a brushless motor have been utilized in practice. However, there are some problems in this method, e.g., the motor can obtain insufficient torque due to the low induced voltages in a low-speed range. This paper proposes a new method which controls the inverter angular frequency ω1 by using inherent characteristics wherein the torque current ir is almost proportional to the internal phase angle φ where the primary flux of a synchronous motor is controlled to be constant. If the parameters of a motor are given exactly, the speed regulation is quite small and the transient characteristics with high response and high starting torque are obtained. Furthermore, it is possible to operate a synchronous motor in the field-weakening range. Here, the principle of the control method and the performance characteristics of a dc brushless motor having no position sensors are discussed. The simulation and the experimental results of the tested machine show that the proposed method is very useful for practical applications.  相似文献   
58.
59.
We describe two cases of non-Hodgkin's lymphoma associated with t(3;6)(q27;p21.3) and BCL6 rearrangement. The first case was in a 78-year old woman, whose performance status (PS) was 1, the serum lactate dehydrogenase (LDH) level was elevated, and the Ann Arbor stage was IIIA with no extra nodal lymphomatous site. The pathological diagnosis from a biopsy of the inguinal lymph node was 'malignant lymphoma (ML), follicular, small cleaved' according to the Working Formulation. Complete remission was achieved. Although she had relapse in 1992, remission was obtained again. The second case was in a 62-year old man, whose PS was 1, the serum LDH was normal, and Ann Arbor stage was IVA with the involvement of the small intestine. Histological diagnosis of the cervical lymph node was 'ML, diffuse, large cell'. Complete remission was obtained without relapse. The 3q27 translocations, found in 20-30% of non-Hodgkin's lymphoma, are unique in having multiple chromosomal translocation partners. Chromosome band 6p21.3 is one of these partner sites that may be the site of a novel gene. The two cases presented here show that this translocation is a non-random chromosomal change involving 3q27 and BCL6. Since t(3;6) was the sole karyotypic abnormality in one case, this translocation may play a role in lymphomagenesis.  相似文献   
60.
The biopsy specimens were homogenized and diluted ten-fold serially in Hank's solution. Each dilution samples were streaked on Skirrow's selective medium. The plates were incubated at 37 degrees C 5 to 7 days under micro-aerobic condition and counting the viable cell of H. pylori. The positive rate of specimens with H. pylori in active gastric ulcer tissue (62.0%) was higher than that in scarred tissue (51.9%). Number of H. pylori viable cells in active ulcer tissue was significantly larger than in scarred tissue. The positive correlation between Raw's gastritis score of specimens from patients with erosive gastritis and number of H. pylori viable cells was clearly noticed.  相似文献   
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