Evaluation of left ventricular function by application of external minute vibration.
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Biomedical subjects
Publications and source records attributed to H Honda.
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The case involves a 57-year-old male who complained of an upper abdominal pain when hungry. An adenosquamous carcinoma of the stomach, however, is rare, and to make such an initial preoperative diagnosis endoscopically from a biopsied specimen is extremely unusual. Thus, as can be expected, on first examination, that the patient had a grade II adenosquamous carcinoma of the stomach was not determined. Two months later, however, on second diagnosis, a primary adenosquamous carcinoma of the stomach in the interior part of the angle region was made after an endoscopic study of a biopsied specimen.
We have observed two cases with marked reading and writing deficits, in which speech and oral comprehension were generally intact. Detailed symptomatological study was performed on these cases, and the lesions were examined organically (X-ray computed tomography [X-ray CT], magnetic resonance imaging [MRI] and functionally (positron emission tomography [PET]. In addition to the marked reading and writing deficits, mild naming and memory disorders were found. X-ray CT and MRI revealed that the lesions were limited to the regions fed by the polar and paramedian arteries in the left thalamus. In one case, PET demonstrated a functional disturbance of the left parietal and temporal lobes in addition to the left thalamus. Most previous cases have shown lesions in the anterior portion of the thalamus. It is possible that the reading and writing deficits in these cases may be due to the thalamic lesion itself, but the PET findings strongly suggest that a secondary cortical lesion may be involved in producing the higher cognitive disorders.
Deviations from the universal genetic code have been reported for several microorganisms. Termination codons are used for coding some amino acids in Paramecium, Mycoplasma or Tetrahymena, and in Escherichia coli, the UGA termination codon is used to code for selenocysteine. In mitochondria, the changes of sense codons to termination codons or to codons encoding other amino acids have also been reported. Here we report another example of divergence from the universal code, this time in a non-spore-forming yeast Candida cylindracea, in which the universal codon for leucine, CUG, is used to code for serine. This conclusion is based on the observations that: (1) the amino-acid composition and the partial amino-acid sequences of an extracellular lipase from this yeast agreed with those deduced from the complementary DNA if CUG was assumed to specify serine; and (2) serine, but not leucine, was incorporated into a polypeptide in a cell-free translation system from this yeast in the presence of a synthetic CUG oligomer.
The study concerned Ca2+ channels that are receptor-operated by norepinephrine (NE) and mediate hyper-reactivity of vas deferens smooth muscle from rats with streptozotocin (STZ)-induced diabetes, and the mediatory responses of these channels, such as tension development, Ca2+ uptake and phosphatidylinositol (PI) turnover. The contractile responses induced by adrenoceptor agonists were significantly greater in diabetic rat vas deferens than in the controls. A greater Ca2+ uptake was induced by 10(-5) M NE in strips from diabetic rats than in the controls. The uptake of Ca2+ was completely inhibited by 10(-6) M prazosin but not by 10(-5) M verapamil. Enhancement of Ca2+ release by 10(-5) M NE was faster and greater in diabetic muscles than in the controls. The accumulation of [3H]inositol phosphates was increased 4-fold in the controls and 7-fold in diabetic muscles by 10(-5) M NE. This increase was completely inhibited by 10(-6) M prazosin but not by 10(-6) M yohimbine. The data suggest that vas deferens smooth muscle hyper-reactivity in diabetic rats is due to increased PI turnover mediated by alpha 1-adrenoceptors, to the release of intracellular bound Ca2+ and to an increase of Ca2+ uptake through receptor-operated Ca2+ channels.
We previously reported setting up an in vitro system for the observation of actin filament sliding along myosin filaments. The system involved a minute amount of fluorescently labelled F-actin, and its movement was monitored by fluorescence microscopy. Here, we report observations of the Ca2+-dependent movement of F-actin complex with tropomyosin plus troponin (regulated actin) added to the movement system in place of pure F-actin. In a wide range of pCa (-log10[Ca2+]) between 3 and 5.5 at 30 degrees C, regulated actin filaments moved rapidly, and the average velocity depended little on the Ca2+ concentration (about 7.5 microns/s). However, when the Ca2+ concentration was decreased to pCa = 5.8 or lower, the filaments suddenly stopped moving. In striking contrast to these observations, unregulated actin moved rapidly within the whole pCa range examined, the average velocity (about 7.5 microns/s) being essentially Ca2+-independent. These observations indicate that (1) tropomyosin-troponin actually gave Ca2+-sensitivity to F-actin, and (2) the movement system was regulated by Ca2+ in an on-off fashion within a narrow range of Ca2+ concentration. In a pCa range between 5.8 and 6.0, regulated actin filaments did not exhibit thermal motion; instead, they had fixed positions in the specimen, possibly because they remained associated with myosin filaments in the background, without sliding past each other. Although regulated actin moved fast in the presence of 1 mM-CaCl2 (pCa = 3) at 30 degrees C, it became entirely non-motile as the temperature was decreased to 25 degrees C or lower. Such a sharp movement/temperature relation was never found for unregulated actin. We assayed regulated actin-activated myosin ATPase in the same conditions as used for microscopy, and found that the ATPase activity depended both on pCa and on the temperature considerably less than the movement of regulated actin. The results suggest that the sliding velocity in the in vitro system would not be proportional to the rate of actin-activated ATPase.
We reviewed the radiographic and pathologic findings in 2 patients with primary adenocarcinoma of the duodenal bulb. Barium studies provided important information, characterizing the nature and extent of the lesion, as well as complete evaluation of the descending and horizontal segments of the duodenum before surgical therapy. Early endoscopy is recommended for nonhealing duodenal ulcers, especially if suggestive malignant changes are present.
1. Disopyramide induced a concentration-dependent decrease in action potential amplitude and Vmax, and prolonged action potential durations (APD50 and APD90) in ventricular muscle. 2. Na+-loaded membrane vesicles isolated from canine ventricular muscle rapidly accumulated Ca2+. 3. Monensin (10(-5) M) abolished Na+-dependent Ca2+ uptake, and Na+ enhanced Ca2+ efflux. 4. Na+-Ca2+ exchange by membrane vesicles was more active in preparations pretreated with disopyramide (10(-5) M) than in control membranes. 5. The results suggest that disopyramide changes Na+ influx from Na+ channel mediated to Na+-Ca2+ exchange mediated. This is verified in part by increased Ca2+ efflux.
The expression of major histocompatibility complex class I antigens was demonstrated on aneurally cultured rat muscle cells. Myoblasts showed constitutive expression of class I antigens on their cell surfaces. The presence of the antigens was transitory, disappearing as myoblasts fused and differentiated into multinucleate myotubes. Furthermore, antibody against rat class I antigens showed an inhibitory effect on the generation of myotubes during muscle development. Although mature myotubes did not show any detectable levels of class I antigens on their cell surface, soluble factors from concanavalin A-activated spleen cells or interferon gamma could induce the expression of class I antigens on muscle fibers. These results suggest that the expression of class I antigens on muscle cells is not only immunologically modulated but also developmentally regulated and that the antigens may play a role in cell recognition and interactions during the fusion process of myogenesis.
Since November 1980, the EEA stapling device has been used to create an end-to-side esophagojejunostomy in 238 patients who underwent total gastrectomy. Failures in the stapling technique were divided into two groups: immediate and delayed. Immediate failures were observed and corrected at the time of surgery. In ten cases, the muscular layer of the esophagus was disrupted, and in three the mucosal layer of the jejunum was disrupted. There were 18 delayed complications: eight cases of anastomotic leakage (3.4%), and ten of stenosis (4.2%). The leakage in one case was classified as major, and those in the other seven as minor. Of the ten stenosis cases, there were five of membranous stricture, four of granular stricture, and one of narrowing after major leakage healing. Only this last case required further surgical treatment. The other nine were successfully dilated either endoscopically or by bougienage.
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New hybrid powders have been produced by the dry processing of six drugs (oxyphenbutazone, prednisolone, theophylline, indomethacin, phenacetin and aspirin), with potato starch used as a core material, by means of an electric mortar and a powder surface reforming system designed to produce hybrid powders. The hybrid powders obtained immediately after production differed in their structure from interactive mixtures. With the hybrid powders the drug was spread on the surface of the core particle by friction and collision that occurred in the dry process, but with interactive mixtures the drug simply adhered as intact particles to the surface of diluent particles. Scanning electron microscopy and powder X-ray diffractometry indicated that the mechanochemical phenomenon was essential for the production of the hybrid powders. With time, a shape change in the adhering drug was observed as a relaxation process took place, with recrystallization resulting from the release of accumulated energy. The change with time might depend upon the method of producing powders and the physical properties of the drug used, e.g. the smooth layer of indomethacin produced by the powder surface reforming system reverted to fine particles tightly adhering to the starch surface, though no change was observed with prednisolone.
We examined the left ventricular functional response to externally applied vibration using four canine open chest preparations. A sinusoidal 30 Hz vibration (2.7 mm in amplitude) was applied to the ventricular epicardium at each level of propranolol-induced myocardial depression. External vibration in control conditions induced no significant change either in peak left ventricular pressure (LVP) or in stroke volume (SV). With propranolol, 0.1 and 0.3 mg/kg, peak LVP and SV were depressed by the application of external vibration, even though there was no significant change of these values in the nonvibrating condition compared to control. We conclude that the ventricular response to vibration depends on the underlying myocardial viability.
We examined the effect of the left ventricular (LV) volume on the magnitude of the vibration induced functional depression (VID) using four canine cross-circulated isovolumically beating LV preparations. A sinusoidal, 50 Hz vibration (1.5 mm in amplitude) was applied to the ventricular anterior epicardium at different values of LV volume which was stepwisely increased by 1-2 ml from 0 to 30 ml. VID was estimated as the difference of the peak LV pressure between control and during external vibration. VID increased as an increment in LV volume when the volume was below 7-8 ml and when peak LV pressure was less than 70 mmHg. However, VID remained constant when the volume increased further. We concluded that VID was independent of LV volume at physiological range.
The left ventricular (LV) incomplete relaxation (IR) has been reported to play an important role in the pathophysiology of the congestive heart failure such as causing higher diastolic pressure and/or impeding the coronary perfusion during diastole. Therefore, using open chest canine preparations (n = 4), we examined 1) whether the minute external vibration during diastole could release IR and 2) what occurred to LV systolic function in this perturbation. LV failure with IR was induced by propranolol administration and, if necessary, by rapid atrial pacing up to 180 beats/min. When we applied a 50 Hz, sinusoidal vibration of 2.1 mm magnitude during diastole to the epicardium of LV with complete relaxation, there was no significant change in the ventricular function. However, the systolic functional improvement (3.8 +/- 1.1 mmHg elevation in LV systolic pressure) was observed when the vibration was applied to LV with IR. We concluded that external vibration at diastole could release IR and would be useful to improve the systolic function of the depressed heart with IR.
In experimental studies, minute sinusoidal vibration has been reported to induce functional depression of the left ventricle and to be an index for evaluation of myocardial crossbridge kinetics. Therefore, to examine whether or not this vibration-induced functional depression could also be observed in the human ventricle, motion of the left ventricular (LV) wall or LV pressure was measured by echocardiography (n = 16) or by left heart catheterization (n = 4), in which 100 Hz, 2.07 mm-amplitude sinusoidal vibration was applied to the subject's precordium. In the echocardiographic study, left ventricular wall shortening did not change by vibration in nine healthy volunteers, but was depressed in two patients with aortic regurgitation (AR) and in one patient with ischemic heart disease (IHD). In measurement of LV pressure, the decrease in LV systolic pressure caused by vibration was obviously observed in two patients (AR and IHD) but was not observed in two patients with hypertrophic cardiomyopathy. These results suggest that we might be able to extend previously proposed experimental idea on early detection of the abnormality in myocardial crossbridge kinetics to the clinical setting.
We examined, noninvasively, the response of the left ventricular (LV) wall to precordially applied vibration in seven normal subjects. The LV posterobasal wall vibration was detected by an esophageal vibration sensor. Even though the amplitude of input vibration was maintained at a constant level, a sharp change in amplitude of the LV wall vibration was observed during the cardiac cycle, especially when 1) the subject was lying in a 45 degree left anterior oblique supine position, 2) the sensor was positioned at approx. 40 cm from the incisor teeth and 3) breath was at expiration. The pattern of this amplitude modulation changed with the input frequency. We concluded that the change in amplitude of output signal must have resulted from LV contraction and relaxation.
The purpose of this study was to determine the CT and sonographic features of hepatic lymphoma developing in organ transplant recipients taking cyclosporine. The four patients included in the study had non-Hodgkin lymphoma. Two of the cases were primary, with no associated lymphadenopathy or extrahepatic lesions. The hepatic lymphomas were characterized by multiple low-density areas on CT scans and hypoechoic areas on sonograms. In three of the four patients, the lesions regressed after the cyclosporine dosage was reduced. We conclude that in cyclosporine-treated organ transplant recipients, hepatic lymphoma should be considered in the differential diagnosis of hepatic lesions with or without lymphadenopathy when multiple low-density lesions are shown by CT and hypoechoic lesions are shown by sonography.