[Value of computed tomography in the differential diagnosis of tuberculoma and peripheral cancer of the lung].
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Adult↗
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Results for “Computer Peripherals”
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Basic principles of computer technology.
This article explains the functions of the different components of computer systems and how they work together. Covered are computer central processors, various peripheral accessories, and the types of software that control them.
Computers↗
Evaluation of peripheral vascular disease by intravenous digital subtraction angiography with the Fuji computed radiography (FCR) system.
Intravenous digital subtraction angiography using Fuji computed radiography system (FCR-DSA) was used to evaluate 57 preoperative patients with clinical manifestations of peripheral vascular disease of lower extremity. With its high contrast resolution and good special resolution, image of FCR-DSA could offer optimal information of vascular abnormality in lower extremity distal to midfoot for the diagnosis and the choice of management.
Adult↗
The use of selective inhibitors and computer modelling to evaluate the role of specific high affinity cyclic AMP phosphodiesterases in the hormonal regulation of hepatocyte intracellular cyclic AMP concentrations.
Using experimentally derived data for the activities and kinetic constants of hepatocyte cyclic AMP phosphodiesterase isoenzymes together with the derived changes in adenylate cyclase activity, due to stimulation and subsequent desensitization by glucagon, a computer model was established to simulate hepatocyte cyclic AMP metabolism. The established ability of glucagon to activate the 'dense-vesicle' cyclic AMP phosphodiesterase by eliciting its cyclic AMP-dependent phosphorylation was shown on the model to be capable of eliciting a profound reduction in the glucagon-stimulated increase in intracellular cyclic AMP. This was consistent with experimentally derived observations using the compound ICI 118233 which was used to inactivate the 'dense-vesicle' enzyme selectively. The non-hydrolysable adenosine agonist N6 (phenylisopropyl)-adenosine (PIA), which prevents glucagon pre-treatment of hepatocytes blocking the ability of insulin to stimulate the peripheral plasma membrane cyclic AMP phosphodiesterase, is shown here to accentuate the ability of insulin to decrease glucagon-elevated intracellular cyclic AMP concentrations. This effect was obliterated using the compound ICI 63197, a selective inhibitor of the peripheral plasma membrane phosphodiesterase. Computer modelling studies, taking into account experimentally derived actions in insulin in activating the peripheral plasma membrane phosphodiesterase, confirmed the potential of this enzyme to decrease intracellular cyclic AMP concentrations. Modelling of the putative effect of an insulin 'mediator' in activating the two cyclic GMP-stimulated cyclic AMP phosphodiesterase isoenzymes was shown to elicit a decrease in intracellular cyclic AMP concentrations which was comparable to that caused by insulin's action on intact hepatocytes. The relative contribution of each phosphodiesterase form to the metabolism of hepatocyte intracellular cyclic AMP, together with an assessment of the potential effect of inhibition and activation of specific species, was evaluated using the computer model. These experimental and stimulation studies indicate that alterations in the phosphodiesterase activity of the 'dense-vesicle' enzyme, the peripheral plasma membrane enzyme, the cyclic GMP-stimulated cyclic AMP isoforms and the IBMX-insensitive PDE-MQ-II can elicit profound effects upon hepatocyte intracellular cyclic AMP concentrations.
3',5'-Cyclic-AMP Phosphodiesterases↗
[An alphabet of hematologic ideographic signs and its use in a computer program assisting the interpretation of microscopic images of the peripheral blood and bone marrow].
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Bone Marrow Cells↗
Mesencephalic hemorrhage and third nerve palsy.
We report the clinical and computed tomography findings in two patients with small mesencephalic hematomas. Both patients presented with unilateral oculomotor paralysis and minor associated neurological symptoms. One patient had pupillary involvement suggestive of a peripheral third nerve lesion. Computed tomography evaluation disclosed small unilateral anterior mesencephalic hematomas involving the oculomotor fascicle. Angiography in both cases and surgery in the first case disclosed no evidence of an arteriovenous malformation or neoplasm. Both patients showed significant clinical improvement within 3 months.
Adolescent↗
[Studies of peripheral nerve conduction velocities in vibrating tool operators].
Vibrating tools such as chain-saws, rock-drills, grinders and tie-tampers have been widely used in many kinds of industries in Japan, causing vibration syndrome among the operators. As is well-known, the syndrome includes disorders of the peripheral circulation in the hands, e.g. Raynaud's phenomenon, and of the peripheral and central nervous systems. As the result of preventive countermeasures to the syndrome during the last decade, the picture of the syndrome has been partly changing especially for the patients among the state forestry workers; for example, the prevalence of the peripheral nerve disorders has been relatively increasing compared with that of Raynaud's phenomenon. Peripheral nerve disorders such as numbness, paresthesia and hypesthesia in the upper limbs tend to be usually cumulative and irreversible. The disorders are very important problem of vibration syndrome from the standpoint of treatment and prevention, though there are only a few reports of the study on the disorders using electrophysiological methods. In order to make objectively clear the peripheral nerve disorders, 236 male vibrating tool operators (= Group V) were examined. The following nerve conduction velocities were measured: (1) Maximal motor nerve conduction velocities (MCV) of the median and ulnar nerves in the forearm. (2) Sensory nerve conduction velocities (SCV) of the median and ulnar nerves in the forearm and palm. (3) Residual latency (RL) of the median and ulnar nerves. Besides, working conditions and complaints relevant to vibration syndrome were examined by using questionnaires. MCVs, SCVs and RLs that were outside of mean +/- 2 S.D. of the control group (= Group C), consisting of 30 healthy men, were evaluated as abnormal. The obtained results led to the following conclusions: (1) All MCVs, SCVs and RLs of Group V were significantly less than those of the control group. In Group V, prevalence of the abnormality in each of forearm SCVs was higher than that in each of MCVs of the corresponding nerves. (2) The difference between the median and ulnar SCV in the palm and the respective SCV in the forearm of each subject was significantly greater for Group V than Group C. (Palm-forearm difference) (3) The difference between the forearm and palmar SCV of the ulnar nerve and the respective velocities of the median nerve was statistically greater for Group V than for Group C. (Ulnar-median difference) (4) Ulnar SCV in the palm of Group V was significantly related to the total operating hours of vibrating tools. (5) There was no significant relation between all the nerve conduction velocities and the white finger attack. But a significant relation was noticed between the prevalence of the abnormal values of ulnar SCV in the palm and the peripheral circulatory function score computed from the data of nail press test and cold immersion test.
Adult↗
[Differential x-ray diagnosis of peripheral formations in the lungs by use of electronic computers. 1. A table of signs and symptoms].
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Computers↗
Image feature analysis and computer-aided diagnosis in digital radiography. 3. Automated detection of nodules in peripheral lung fields.
We are investigating the characteristic features of lung nodules and the surrounding normal anatomic background in order to develop an algorithm of computer vision for use as an aid in the detection of nodules in digital chest radiographs. Our technique involves an attempt to eliminate the background anatomic structures in the lung fields by means of a difference image approach. Then, feature-extraction techniques, such as tests for circularity, size, and their variation with threshold level, are applied so that suspected nodules can be isolated. Preliminary results of this automated detection scheme yielded high true-positive rates and low false-positive rates in the peripheral lung regions of the chest. This detection scheme, which can assist the final diagnosis by the clinician, has the potential to improve the early detection of lung carcinomas.
Diagnostic Errors↗
A model of the peripheral auditory system.
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Animals↗
[Experiences with computer-assisted x-ray diagnosis of pulmonary coin lesions (author's transl)].
Favourable results of the computer-aided diagnosis of peripheral bronchial carcinoma lead to a simplified scheme for calculation fo diagnosis, basing upon X-ray symptoms. This scheme was tested in the Zentralinstitut für Krebsforschung (ZIK) in 102 pateints and in the Forschungsinstitut für Lungenkrankheiten und Tuberkulose (FLT) in 101 patients. These patients had coin lesions of the lung with unknown diagnoses. The histological diagnoses later proved were compared with the calculated diagnoses. In ZIK there were correct diagnosis in 92.16% (in 96.53% of the carcinomas, in 44.4% of the tuberculomas and in all benign tumors), while in FLT 85.53% of the coin lesions were correctly classified (89.13% of carcinomas, 79.31% of the tuberculomas and all benign tumors). The comparison with the clinical-histological diagnoses showed a clear improvement of the accuracy by the calculated diagnoses. The method can be recommended for the basic diagnosis especially of peripheral bronchial carcinoma. It implies a reduction of the diagnostic delay, but it can not substitute the histologic investigation of the lesions.
Adult↗
Far-field potentials in muscle.
Far-field potentials have been predicted by computer simulations as well as demonstrated in both animals and humans with respect to the peripheral and central nervous systems. Computer simulations have also predicted far-field potentials originating at the termination of muscle tissue. This investigation demonstrates the occurrence of 2 far-field potentials in the human biceps muscle resulting from action potential termination at the musculotendonous junctions. A monophasic potential is produced at both the muscle's origin and insertion, and the polarity is entirely dependent upon the recording montage. Sequential stimulation of the biceps muscle at 2.5-cm increments resulted in the 2 far-field potentials and their respective latencies changing proportional to the distance between the stimulus site and the 2 musculotendonous junctions. Various stimulation and recording montages are used to investigate the properties of these far-field potentials. The leading/trailing dipole model is utilized to explain the production and polarity of far-field potentials generated by muscle tissue.
Action Potentials↗
Transient abdominal granulomas in children.
Space-occupying liver lesions in febrile patients are usually caused by tumor or infection and other causes are seldom encountered. In five patients age 20 months to 12 years who were evaluated for fever of unknown origin, imaging studies revealed hepatic nodules consisting of transient, sterile granulomas for which no cause could be determined. Stellate architecture histologically supported clinical evidence of subacute bacterial infection. Imaging modalities included: 99Tc-sulfur colloid (n = 2) and 67Ga (n = 2) scintigraphy; ultrasound (n = 5); computed tomography (n = 4); and magnetic resonance imaging (n = 2). Peripheral low density, as revealed by computed tomography in one and hyperintense halos on magnetic resonance imaging of another patient are both considered predictive for neoplastic disease but were associated with granulomas. The differential diagnosis of macroscopic liver lesions seen on imaging studies in febrile children should include the possibility of transient, idiopathic granulomas.
Child↗
[Characteristics of central and peripheral hemodynamics in infants with hemolytic disease of newborn].
Overall 82 full-term neonates (52 children with hemolytic disease and 30 healthy neonates) were examined. The general circulation was investigated over time (on days 1, 3.5-7 of life). Use was made of echocardiography and monitor studies of arterial pressure and heart rate; lability of arterial pressure and general peripheral vascular resistance were computed. As a result of the studies and correlations, it has been revealed that neonates with hemolytic disease manifest appreciable disorders of the cardiovascular system, correlating with the disease gravity. Earlier times of the closure of fetal communications were established as were the hyperkinetic type of +cardiac hemodynamics, arterial hypotension accompanied by arterial pressure instability and a decrease of the general peripheral vascular resistance which should be taken into consideration in choosing therapeutic measures.
Cardiovascular System↗
On the biologically active structures of cholecystokinin, little gastrin, and enkephalin in the gastrointestinal system.
The biologically active conformations of a series of four peptides [four cholecystokinin (CCK)-related peptides and enkephalin] in their interactions with gastrointestinal receptors have been deduced using conformational computational analysis. The two peptides that interact exclusively with peripheral-type CCK receptors are the heptapeptide COOH-terminal fragment from CCK (CCK-7) and the analogous sequence from cerulein (CER-7) in which threonine replaces the methionine proximal to the NH2 terminus. The two peptides that interact exclusively with the gastrin receptor in the stomach are the active COOH-terminal fragment of little gastrin and the COOH-terminal tetrapeptide sequence common to all of these peptides, CCK-4. We find that preferred conformations for the peripherally active peptides CCK-7 and CER-7 are principally beta-bends, whereas little gastrin and CCK-4 are fundamentally helical. In the class of lowest energy structures for both CCK-7 and CER-7, the aromatic rings of the tyrosine and phenylalanine lie close to one another whereas the tryptophan indole ring points in the opposite direction. This structure is superimposable on the structures of a set of rigid indolyl benzodiazepine derivatives that interact with complete specificity and high affinity with peripheral CCK receptors further suggesting that the computed beta-bends are the biologically active conformation. The biologically active conformation for CCK-4 and the little gastrin hexapeptide has also been deduced. By excluding conformations common to CCK-7 and CCK-4, which do not bond to each other's receptors, and then by selecting conformations in common to CCK-4 and the gastrin-related hexapeptide, which do bind to each other's receptors, we deduce that the biologically active conformation at the gastrin receptor is partly helical and one in which the indole of tryptophan and the aromatic ring of phenylalanine are close to one another while the methionine and aspartic acid side chains point in the opposite direction. These major differences in preferred structures between the common CCK-7/CER-7 peptides and the common CCK-4/little gastrin peptides explain the mutually exclusive activities of these two sets of peptides. We have observed that [Met]enkephalin strongly antagonizes the action of the naturally occurring peripherally active CCK-8 (CCK-7 with an NH2-terminal aspartic acid residue added). The computed lowest energy structures for this opiate peptide closely resemble key features of the computed CCK-7/CER-7 structure, further supporting the proposed structure.
Amino Acid Sequence↗
Clinical significance of hematic cyst of the orbit.
Hematic cyst is a rarely encountered orbital lesion consisting of encapsulated blood or blood breakdown products. The abnormality may be recognized by identifying the cystic structure by B-scan ultrasonography or computed tomography. Cysts located peripherally in the orbit tend to have histologic features suggesting hematoma formation. More centrally located orbital cysts are sometimes associated with vascular abnormalities. In other cases, the etiology is obscure, as in the case presented here. The visual prognosis is usually good, and associated systemic abnormalities are lacking.
Adult↗
Peripheral nerve function in sepsis and multiple organ failure.
Forty-three patients who had sepsis and multiple organ failure (critical illness) were studied prospectively to determine the incidence and severity of peripheral nerve function and to correlate such function with a number of variables. Electrophysiologic studies indicated a primary axonal degeneration of motor and sensory fibers in 30 (70 percent). Fifteen (30 percent) had the clinical signs of difficulty in weaning from assisted ventilation, weakness of limb muscles, and reduced or absent deep tendon reflexes. Full recovery from the polyneuropathy occurred among the 23 (53 percent) who survived, except three who had a very severe polyneuropathy. A peripheral nerve function index, computed from electrophysiologic measurements, showed statistically significant (p less than 0.01) negative correlations with the time in the critical care unit, and the serum glucose value; the serum albumin level showed a positive correlation. Multiple regression analyses indicated all three factors accounted for 47 percent (r2 = 0.4678) of all potential variables. In a separate analysis, the nerve function index correlated with the amplitude of the diaphragm compound muscle action potential (p less than 0.01). The results were consistent with the polyneuropathy being due to the same mechanisms that are currently postulated to cause dysfunction in this syndrome of other organ systems (including the neuromuscular respiratory system).
Bacterial Infections↗
Changes in systemic vascular resistance detected by the arterial resistometer: preliminary report of a new method tested during percutaneous transluminal coronary angioplasty.
A recently developed apparatus provides on-line continuous monitoring of systemic vascular resistance (SVR) by means of simple computer analysis of the peripheral arterial waveform. The fundamental equation of this method is Ri = P'/(dP/dt), where dP/dt is the peak dP/dt of the peripheral arterial waveform, P' is the pressure at time of peak dP/dt, and Ri is a resistance index that bears a direct relation to SVR. Eleven patients undergoing percutaneous transluminal coronary angioplasty (PTCA) were studied to evaluate the changes in SVR associated with myocardial ischemia (angina detection). There were 49 balloon inflations, all of which were associated with an increase in Ri (from 38.4 +/- 12 to 81.2 +/- 36 X 10(-3) sec; p less than .01) and a decrease in dP/dt (from 2076 +/- 257 to 1327 +/- 326 mm Hg/sec; p less than .01). In 42 of the balloon inflations these changes were associated with electrocardiographic ST-T changes and in 23 it was also associated with anginal pain. When angina was present, a further increase in Ri (to 97.5 +/- 43 X 10(-3) sec; p less than .01) and a decrease in dP/dt (to 1218 +/- 338 mm Hg/sec; p less than .01) was observed. It was found that myocardial ischemia is associated with an increase in the resistance index and a decrease in dP/dt and can be detected by the resistometer.
Angioplasty, Balloon↗