Doppler echocardiographic estimates of pressure gradients in various types of stenoses: usefulness and limitations

In the present study, the accuracy of Doppler estimates of pressure gradients in various types of stenoses was clinically and experimentally evaluated. Fifty-seven patients, including 23 with ventricular septal defect, 15 with aortic or pulmonary valvular stenosis, four with infundibular stenosis, and five with supravalvular aortic or pulmonary stenosis were observed. The peak systolic pressure gradient (dP (C] was obtained at the time of catheterization in all patients. Before catheterization, the maximum velocity was measured by pulsed or continuous Doppler echocardiography and the estimated systolic pressure gradient according to Doppler (dP (D] was calculated by the simplified Bernoulli equation. The experimental model was designed to create pulsatile flow through a stenosis model. Nine different stenotic model types were used, including three orifice-like stenoses and six truncated cones with heights of 10 mm and 20 mm distal to the stenosis. The orifices in their stenoses were 3, 4 and 5 mm, respectively. Glycerin solution containing Sephadex with a viscosity similar to that of blood was used as the circulation medium. Its specific gravity was 1.16 g/cm3. In each stenotic model, the maximum velocity and instantaneous systolic peak pressure gradient were measured at various water flow rates. Clinical results: In patients with ventricular septal defect or valvular stenosis, dP (D) correlated very well to dP (C), with the regression equation, y = 0.87x + 2.79 (r = 0.92) or y = 0.96x + 1.02 (r = 0.99). In the other patients except for three with patent ductus arteriosus, dP (D) overestimated dP (C) by 11 to 71 mmHg, and their post-stenotic areas had gradually widened according to angiographic findings.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of combined therapy with irradiation, cisplatin and vindesine in lymph node recurrence of esophageal cancer

The effects of combined therapy with irradiation, cisplatin and vindesine for lymph node recurrence of esophageal cancer was studied. The subjects were 95 patients with lymph node recurrence, who were divided into the following four treatment groups: Group I: Radiotherapy alone (R) (n = 31); Group II: cisplatin (CDDP) alone (n = 18); Group III: R + CDDP(n = 9); Group IV: R + CDDP + VDS (n = 10). The response rate (CR + PR) of Groups III and IV was 66.7% and 100%, respectively, which was significantly more favorable than 11.1% of Group II. The survival duration after recurrence was prolonged in the order of Group IV, Group III, Group II and Group I. In conclusion, combination therapy using R, CDDP and VDS will be effective for lymph node recurrence of esophageal cancer.     

Immunohistochemical demonstration of serotonin nerve fibers in the neocortex of the monkey (Macaca fuscata)

Using a peroxidase-antiperoxidase immunohistochemical method, the distribution of serotonin nerve fibers was studied in the neocortex of the monkey (Macaca fuscata). All layers of the neocortex showed evidence of serotonin fibers, both fine and thick. Unlike the distribution in rodents, different patterns of distribution were noted in each neocortex of the primate. Among the cortical areas--area 4, 3-1-2, 17, 18, 41 and 42--the primary visual cortex (area 17) contained the highest density of immunoreactive fibers, while the primary motor cortex (area 4) possessed the lowest concentration. The most outstanding finding was a dense and laminar distribution of serotonin fibers in area 17, particularly within the upper portion of layer IVc. In area 3-1-2, 18, 41 and 42, a fairly uniform density of immunoreactive fibers was observed across the six cortical layers, apart from a relatively dense plexus of fine serotonin fibers in layer IV.     

An experimental study on histamine H2-receptor antagonist on calcium, gastrin and histamine induced gastric acid secretion in rat

The suppressive effect of histamine H2-receptor antagonist, cimetidine, on gastric secretion was investigated in Ghosh-Schild rat. The study above was done in basal state under infusing normal saline (1 ml/h) and stimulated state by histamine-di-chloride (3.5 mg/kg-h), tetragastrin (50 mcg/kg-h) or calcium chloride (4 mg/kg-h). Dose related increase of cimetidine (1.7, 3.5, 7.0 and 14.0 mg/kg-h) were observed and correlated with the degree of inhibition of acid secretion. Cimetidine had a potent inhibitory activity on either basal and stimulated acid output by the agents above. Basal acid secretion was completely abolished by 3.5 mg/kg-h of cimetidine to the level of anacidity. The degree of inhibition by the same dose of cimetidine was different among the agents used as stimulant on acid secretion and it followed in the order of calcium, gastrin and histamine subsequently. This study indicated that histamine H2-receptor participated the gastric secretion induced by either gastrin or calcium other than histamine itself. This fact indicated the important role of endogenous histamine in gastric secretion induced by calcium and gastrin.     

Aging effects on upper and lower half visual fields by VECPs and automated static perimetry

We studied the aging effects on upper and lower half visual fields using pattern VECPs with half fields stimuli and automated static perimetry. The subjects, consisting of 56 normal volunteers ranging in age from 10 to 69 years old, were divided into three groups (10-29, 30-49, 50-69 years old). Their visual acuities were better than 1.0 and refractive errors were within +/- 2.0 diopters. Perimetry was performed with an automated perimeter (Octopus, program 61). An artificial pupil of 3 mm was used after cycloplegia with 1% tropicamide to eliminate senile miosis effects in recording of VECPs. Subjective light sensitivity decreased with age and there was a noticeable hiatus between the third and fourth decades. However the age-related decrease in sensitivity showed no difference between the upper and lower half fields. However VECPs results showed that with aging the P100 peak latency did not increase for lower half field stimuli, but increased for the upper half field stimuli, especially for smaller check sizes. These results suggested that there were different aging processes a in the upper and lower half fields and higher neural factors participated in the effects.