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At least 163 records · Page 9Linked to original sources
PubMed1989

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↗
PubMed1992

[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↗
PubMed1987

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↗
PubMed1988

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↗
PubMed1991

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↗
PubMed1986

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↗
PubMed1987

Beat-to-beat estimation of peripheral resistance and arterial compliance during pressure transients.

We have used a computer-based parameter estimation method to obtain peripheral resistance, total arterial compliance, and characteristic resistance from the measurement of aortic pressure and flow in the open-thorax cat, assuming the three-element windkessel as a model of the systemic arterial tree. The method can be applied on a beat-to-beat basis in the steady state and in transients. We have validated this method by analyzing nonsteady-state data obtained from an electrical analog with fixed values of the resistances and compliance and by showing that the values obtained by this procedure were within 5% of the fixed values of the circuit. Changes in total peripheral resistance and arterial compliance were studied before, during, and after acute heart rate changes in five open-thorax cats with blocked autonomous nervous system. As expected, the peripheral resistance, estimated during the heart rate transient [3.93 +/- 0.94 (SE) kPa X ml-1 X s] was the same as before the transient (3.53 +/- 0.83 kPa X ml-1 X s); total arterial compliances were also identical (0.28 +/- 0.04 vs. 0.27 +/- 0.03 ml/kPa). In six cats without nervous blockade we obtained similar results. Calculation of peripheral resistance during transients from the mean pressure-to-mean flow ratio, i.e., without correction for arterial compliance, suggested changes in resistance values of less than or equal to 57%, which shows that correction is necessary. The findings indicate that peripheral resistance and total arterial compliance can be estimated in vivo on a beat-to-beat basis, even during hemodynamic transients.

Animals↗
PubMed1984

Subpleural pulmonary hamartoma: demonstration by computed tomography.

A case of a subpleural pulmonary hamartoma demonstrated by computed tomography is presented. The literature on subpleural pulmonary lesions demonstrated by computed tomography is reviewed. Although peripheral pulmonary hamartomas have been well documented, we believe this is the first demonstration of a subpleural location by computed tomography scanning. In the appropriate clinical setting, pulmonary hamartoma should be included in the differential diagnosis of subpleural lesions identified on computed tomography scanning of the chest.

Aged↗
PubMed1986

Rat heart fatty acid-binding protein is highly homologous to the murine adipocyte 422 protein and the P2 protein of peripheral nerve myelin.

The rat heart contains an abundant cytosolic protein which binds long chain fatty acids. We have determined its primary structure by Edman degradation of peptides generated from chymotryptic, tryptic, and elastase digestions. This polypeptide (Mr = 14,992) contains 134 amino acids and has a blocked (acetylated) NH2 terminus. The sequence of rat heart fatty acid-binding protein (FABP) is remarkably similar to the murine adipocyte 422 protein and the P2 protein of peripheral nerve myelin. Computer-assisted alignment of heart FABP and 422 revealed that 82 of 132 comparable residues are identical (62%). There are 77 identities out of 131 possible matches between this protein and the human myelin P2 protein (59%). Similar comparisons demonstrate that heart FABP has significant homology to several other proteins which bind hydrophobic ligands. The rank of order of similarity to heart FABP is: 422 greater than myelin P2 greater than cellular retinoic acid-binding protein greater than cellular retinol-binding protein II greater than cellular retinol-binding protein greater than intestinal FABP greater than liver FABP. These eight sequences form a family of paralogous homologues. Heart FABP has a region of internal homology involving tandemly arrayed oligopeptides spanning residues 71-100 and 101-131. This feature is not found in the 422 and P2 sequences. The endogenous ligands bound by the 422, P2, and heart FABP sequences have not been defined. Interpretation of the biological significance of their structural similarities and differences will require information about their ligand specificities and affinities.

Amino Acid Sequence↗
PubMedDate not supplied

A method for continuous on-line monitoring of systemic vascular resistance (COMS) after open heart procedures.

A new method for continuous on-line measurement (COMS) of systemic vascular resistance (SVR) utilizing simple computer analysis of the peripheral arterial waveform is presented. The fundamental equation of this method is: (Formula: see text) where SVR is systemic vascular resistance, dP/dt is the peak dP/dt of the peripheral arterial waveform, and P' is the pressure at the time of peak dP/dt. F and a are calibration constants determined by taking simultaneous measurements by an independent method (thermodilution) before (low SVR) and immediately after (high SVR) aortocoronary bypass operations. In 22 patients 255 COMS of SVR readings were recorded simultaneously with thermodilution cardiac output measurements. Patients were exposed to situations such as temperature changes, volume load, blood loss, and the effect of drugs such as various catecholamines, nitroglycerin, and nitroprusside. Linear regression analysis was performed to compare the SVR calculated from thermodilution with the COMS-SVR measurements. SVR values ranged from 450 to 4400 dynes/sec/-5 and correlation between COMS and thermodilution was r = 0.98. Correlation coefficients of individual patients ranged from r = 0.9 to r = 0.986. We found COMS SVR measurements accurate, reliable, and extremely helpful in the management of hemodynamically unstable patients.

Adult↗
PubMed1985

[Determination of the ejection fraction of the left ventricle by videodensitometric analysis of digital angiography. Preliminary results].

Digitalisation enables angiocardiography to be performed by a peripheral intravenous injection. Computer-assisted analysis of the date widens the possibilities of quantification. The authors have developed a videodensitometric method of studying the left ventricular ejection fraction. The research was performed on an experimental model and the technique validated in a series of 10 patients. The experimental model consisted of a series of balloons which, when inflated with contrast medium assumed an allipsoid shape resembling a left ventricle. The balloons were blown up in two stages with an automatic injector to simulate systole and diastole. The images were recorded in the same way as during ventriculography. Videodensitometric measurements showed 3 to 5% variations from the true values. The method was then applied to the calculation of the left ventricular ejection fraction in 10 patients: left ventricular function was also quantified by geometrical methods (Dodge) from the same angiogrammes and the 2 sets of results were then compared. The correlation coefficient between the two methods was 0.97, so validating the new technique. Videodensitometry opens up new perspectives in the study of left ventricular function. On the other hand it can be used to monitor the ejection fraction in severely ill or recently operated patients, and, on the other hand the principle of videodensitometry eliminates the geometrical approximations inherent in the classical methods of angiographic analysis and would therefore seem to be more suitable for the study of pathological left ventricules (aneurysm...). Finally, the technique of videodensitometry represents a new step towards the measurement of true volumes and flow rates.

Absorptiometry, Photon↗
PubMed1982

New concepts of ventilation.

A short survey is given of established methods for ventilatory support. The merits of intermittent mandatory ventilation (IMV) and the new mode of mandatory minute ventilation (MMV) are discussed and compared. The importance of gasflowpressure patterns are analyzed as based on measurements on an awake, non-medicated intubated subject. It can be demonstrated that an inspiratory-assist function minimizes the work of breathing associated with increased airway resistance in the peripheral airways. A metabolic computer system for automatic continuous measurements of oxygen uptake and carbon-dioxide elimination during ventilatory care is described. This metabolic computer is designed to be used with the Engström Erica ventilator and makes it possible to evaluate the caloric demand of the patient as well as the effects of various compositions used for parenteral nutrition.

Airway Resistance↗
PubMedDate not supplied

[An automated system for evaluating the state of peripheral hemodynamics].

A four-channel automated system based on the microelectronic computer "Elektronika-60M" for investigation of human peripheral hemodynamics is described. The block diagram of algorithm of the automated system operation is adduced, search algorithm of characteristic points is described in detail, the fundamental correlations are presented.

Algorithms↗
PubMed1990

Use of a touch sensitive screen and computer assisted image analysis for quantitation of developmental changes in pulmonary structure.

The extensive changes in pulmonary function occurring during early development may reflect variations in the anatomic structure of the respiratory apparatus during this period. Accurate definition of these alterations could yield important information concerning the structure-function correlations of the respiratory system. To facilitate the acquisition of morphometric data from histologic sections of pulmonary tissues, we propose the use of a computer assisted image analysis system with a touch sensitive screen as an interactive peripheral. This allows planimetric measurements and computation of the dimensions of areas of selected light intensities within an image. We present the description, design, and applications of such an image analysis system and report representative results regarding developmental changes in pulmonary structure. In addition, we correlate these results with previously published information regarding pulmonary mechanics during early development to help clarify the maturational changes in pulmonary structure-function relationships.

Animals↗
PubMed1985

Thermographic presentation of cutaneous sensory and vasomotor activity in the injured peripheral nerve.

Impaired function of cutaneous segments of monkey peripheral nerves experimentally blocked by lidocaine anesthesia was clearly visualized by means of elevated temperature measurements obtained on computerized color telethermography. Mean temperature elevations in the segments of anesthetized primate nerves were 2.40 degrees C at the ulnar segment 17 minutes after nerve block, and 1.20 degrees C at the peroneal nerve at 20 minutes. The vasomotor activity of specific nerves, recorded after local anesthesia and displayed by color telethermographic imaging, corresponded to the distribution of sensory segments identified by more cumbersome means. Telethermography is therefore shown to be a useful tool, both qualitatively and quantitatively, in mapping cutaneous distribution of peripheral nerves and for evaluation of peripheral nerve injuries.

Animals↗
PubMed1991

Bronchiolitis obliterans after lung transplantation: findings at chest radiography and high-resolution CT. The Toronto Lung Transplant Group.

Although bronchiolitis obliterans (BO) is seen commonly after heart-lung transplantation, its occurrence after lung transplantation appears to be relatively infrequent. In the 55 single- and double-lung transplantations performed at Toronto General Hospital, 41 patients have survived longer than 3 months and four (10%) have developed pathologically proved BO. Chest radiographic findings in these four patients included slight to moderate decreased peripheral vascular markings (n = 3), slight to moderate volume loss (n = 2), subsegmental atelectasis (n = 2), and new, thin, linear, irregular areas of increased opacity (n = 2). High-resolution computed tomography (HRCT) demonstrated mild peripheral bronchiectasis (n = 4) and decreased peripheral vascular markings (n = 3). Although the radiographic and HRCT findings did not appear to be specific for posttransplantation BO, they may be of value in suggesting the diagnosis of BO within this patient population.

Adult↗