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Biomedical subjects

S Treves

Publications and source records attributed to S Treves.

At least 73 records · Page 4Linked to original sources
PubMed1984

Characterization of the inflammatory cells in progressing tumor-like alveolar hydatid cyst. 2. Cell surface receptors, endocytosed immune complexes and lysosomal enzyme content.

Alveolar hydatid cysts (LCM) grow progressively and contribute significantly to the morbidity of hydatid-hosts. To examine whether modifications in immune effector parameters correlate with the pattern of LCM growth, in vivo experiments were carried out in C57BL/6J mice infected intraperitoneally with LCM. Immigrant peritoneal and intra-LCM leukocytes were tested for the loss of cell surface receptors, membrane-bound and internalized immune complexes (ICs) and lysosomal enzyme contents during the restrictive and progressive growth phases of the LCM. The proportion of Fc and C3b receptor-bearing intra-LCM leukocytes decreased 2-fold and 31 to 72% of the leukocytes contained ICs during the progressive phase of the LCM. Acid phosphatase and beta-glucuronidase activities of macrophages declined sharply during the restrictive phase but they gradually increased as the infection progressed. IC-mediated dysfunction of effector leukocytes and modulation of antibody dependent cell cystolysis mechanism are discussed in murine hydatidosis.

Acid Phosphatase↗
PubMed1984

Characterization of the inflammatory cells in progressing tumor-like alveolar hydatid cysts: 1. Kinetics and composition of inflammatory infiltrates.

The kinetics and composition of leukocytic infiltrates from the biphasically growing parasite biomass and the peritonea of C57BL/6J mice infected intraperitoneally with Echinococcus multilocularis cysts were studied. During the first 6 to 8 weeks postinfection (p.i.) the larval cyst masses (LCM) grew slowly, weighted 1 g and contained 3 to 4 X 10(6) leukocytes/100 mg of LCM. Subsequently, (8 to 16 weeks p.i.) the growth of the LCM was rapid and was accompanied by 3 to 4-fold reduction in the absolute leukocyte count; monocytoid cells, neutrophils, eosinophils and T-lymphocyte significantly decreased during the progressive growth phase of the LCM. The cumulative data show a strong inverse relationship between the mean LCM weights and the absolute or relative counts of intra-LCM leukocytes. The data suggest that high concentrations of intra-LCM leukocytes, especially monocytoid cells and to a lesser degree eosinophils, regulate the growth of the LCM in C57BL/6J mice.

Animals↗
PubMed1984

The relationship of gastroesophageal reflux and gastric emptying in infants and children: concise communication.

One hundred twenty-six pediatric patients (0-16 yr of age) with clinically suspected gastroesophageal reflux (GER) were evaluated using radionuclide scintigraphy. Although 46 of the patients (38.3%) had abnormal studies exhibiting evidence of GER, there were no significant differences in gastric emptying between patients with and without GER. At 60 min after ingestion, the 76 patients less than 2 yr old had a mean residual of 54%, whereas those over 2 yr of age had a value of 29% (P less than 0.0001). Gastric emptying values may be age-related.

Adolescent↗
PubMed1983

Quantitation of aortic and mitral regurgitation in the pediatric population: evaluation by radionuclide angiocardiography.

The ability to quantitate aortic (AR) or mitral regurgitation (MR), or both, by radionuclide angiocardiography was evaluated in children and young adults at rest and during isometric exercise. Regurgitation was estimated by determining the ratio of left ventricular stroke volume to right ventricular stroke volume obtained during equilibrium ventriculography. The radionuclide measurement was compared with results of cineangiography, with good correlation between both studies in 47 of 48 patients. Radionuclide stroke volume ratio was used to classify severity: the group with equivocal regurgitation differed from the group with mild regurgitation (p less than 0.02); patients with mild regurgitation differed from those with moderate regurgitation (p less than 0.001); and those with moderate regurgitation differed from those with severe regurgitation (p less than 0.01). The stroke volume ratio was responsive to isometric exercise, remaining constant or increasing in 16 of 18 patients. After surgery to correct regurgitation, the stroke volume ratio significantly decreased from preoperative measurements in all 7 patients evaluated. Results from the present study demonstrate that a stroke volume ratio greater than 2.0 is compatible with moderately severe regurgitation and that a ratio greater than 3.0 suggests the presence of severe regurgitation. Thus, radionuclide angiocardiography should be useful for noninvasive quantitation of AR or MR, or both, helping define the course of young patients with left-side valvular regurgitation.

Adolescent↗
PubMed1983

Gallium-67 scintigraphy in children with chronic granulomatous disease.

Gallium-67 has been extensively used to diagnose and localize adult and pediatric inflammatory, infectious and malignant disease. Its mechanism of localizing in pathologic foci, although the subject of numerous studies both in vitro and in vivo, has not been clearly understood yet. The presence of normal polymorphonuclear leukocytes has been reported to be important in the accumulation of the tracer in inflammatory sites. We reviewed our experience with Gallium scintigraphy in three children with chronic granulomatous disease, an entity characterized by defective neutrophils and recurrent infection. Radiogallium was found to localize in inflammation in these patients. Hematologic disorders with specific structural or biochemical defects in their polymorphonuclear leukocytes may provide important information as to how these cells contribute to the accumulation of Gallium-67 in inflammation.

Adolescent↗
PubMed1983

Radionuclide voiding cystography.

Radionuclide voiding cystography is a sensitive and accurate method for diagnosing vesicoureteric reflux. This method allows for continuous monitoring of bladder filling and emptying, permits detection of reflux at any time during the study, and evaluates its dynamics. Since it results in very low amounts of radiation to the patient, it is an ideal method for the diagnosis and follow-up of children with reflux.

Child↗
PubMed1983

Radionuclide angiocardiography: an improved deconvolution technique for improvement after suboptimal bolus injection.

Deconvolution is a mathematical technique used to improve radionuclide angiocardiography after suboptimal injection of radiopharmaceutical. A new deconvolution algorithm designed to be relatively insensitive to the random errors that occur in experimental data was tested. First-pass radionuclide angiocardiography using iridium-191m was performed to quantitate left-to-right shunting in normal dogs and dogs with atrial septal defects. Deconvolution was used to correct for injection shape. Four quantitation techniques were studied (good injection/no deconvolution, good injection/deconvolution, fragmented injection/no deconvolution, fragmented injection/deconvolution). The mean (p less than .001) and standard deviation (p less than .0001) of the fragmented injection/no deconvolution technique were significantly different from the other three techniques, which were not significantly different from each other (mean or standard deviation) at the p = 0.05 level. This deconvolution method made it possible to accurately quantitate left-to-right shunts even with fragmented injections.

Animals↗
PubMed1983

Granular and globular acid alpha-naphthyl-acetate-esterase staining pattern of resting and mitogen-activated murine lymphocytes.

Available methods for the identification of T-lymphocytes in tissue sections and in single cell suspensions are often tedious and require a lot of manipulation. Here we confirm previous findings that nonspecific alpha-naphthyl-acetate esterase (ANAE) is a reliable method for the identification of resting thymus-derived lymphocytes but not for concanavalin-A-stimulated lymphocytes, as a small proportion of lipopolysaccharide-stimulated lymphoblasts exhibit ANAE activity as well. We have also shown that there is a relationship between the globular staining pattern and the degree of cell activation. Finally, we noted that prolonged incubation of lymphocytes at 37 degrees C reduces the number of ANAE-positive cells.

Animals↗
PubMed1983

Changes in pulmonary blood flow affect vascular response to chronic hypoxia in rats.

We banded the left pulmonary artery in rats to investigate, in the same animal, the effect of both increased and decreased flow on the lung vasculature and to determine how these hemodynamic states modify the structural changes produced by a 2-week exposure to hypobaric hypoxia. In unanesthetized rats, pressures were recorded from the main pulmonary artery and aorta via indwelling catheters, cardiac output was calculated by the Fick principle, and pulmonary and systemic vascular resistance estimated. Technetium-99m macroaggregated albumin was injected and radionuclide activity counted separately over the right and left lungs as a measure of flow. At postmortem, right and left ventricles of the heart were weighed and the lungs injected to permit analysis of arteriograms and morphometric assessment of structural changes in the pulmonary vascular bed. Flow in the left lung was reduced to one-fifth normal in rats with left pulmonary artery bands. In "room air" rats, pressure proximal to the left pulmonary artery band and in the right lung was slightly higher than in nonbanded controls, but not as high as in nonbanded or banded hypoxic rats. Changes in flow and pressure in both lungs of "room air" rats with left pulmonary artery bands were associated with a mild degree of extension of muscle into peripheral pulmonary arteries normally nonmuscular, medial hypertrophy of normally muscular arteries, and reduced arterial density. These three structural changes were present in both lungs of "hypoxic" rats but were much more severe. High flow in the right lungs of "hypoxic rats" with left pulmonary artery bands worsened only the degree of extension. Decreased flow and pressure in the left lungs of these animals prevented both the extension and the medial hypertrophy of hypoxia, but not the severe reduction in arterial density. It seems that the latter may occur as a direct response to low oxygen tension, whereas extension and medial hypertrophy are influenced by altered flow and pressure, respectively.

Animals↗
PubMed1983

Radionuclide evaluation of circulatory shunts.

With first-pass radionuclide angiography, it is possible to visualize sequentially the cardiovascular structures and to obtain computer-generated time-activity curves for regions of interest over these structures. Analysis of these curves permits the detection, localization, and quantitation of intracardiac shunts and shunts between the great arteries. The authors present the formulae used for the quantitative analysis and discuss clinical applications.

Ductus Arteriosus, Patent↗
PubMed1983

Accuracy of deconvolution algorithms assessed by simulation studies: concise communication.

Deconvolution has been used to correct first-pass radionuclide angiocardiography for the time course of the delivery of radiopharmaceutical into the cardiopulmonary system. The extreme sensitivity of deconvolution to random errors in the data may account for some of the problems encountered in practice. We implemented several deconvolution algorithms that were suitable for use with the unimodal and multimodal superior vena caval and pulmonary curves found in left-to-right shunt quantification. The sensitivity of the algorithms to random errors was assessed using mathematical test problems degraded with pseudorandom noise. An algorithm that constrained the deconvolved pulmonary curve to be expressable as the non-negative sum of a set of lagged normal curves was found to have the smallest maximum error on the curves tested. Comparison with results from a previously published test problem indicated an error reduction of greater than 50% over previously used algorithms. Use of this algorithm may permit more accurate deconvolution of pulmonary time-activity curves and thereby improve shunt quantification.

Heart↗
PubMed1983

Analgesic effect of peridural labetalol in the treatment of cancer pain.

Labetalol is an alpha- and beta-blocking agent commonly used in anti-hypertensive therapy. Because of its beta-blocking and local anesthetic effect, labetalol via peridural catheter was supposed to reduce pain in patients suffering from gynecologic cancers. Thirty patients with terminal carcinomas (breast, uterus, ovary), whose pain was caused either by bone metastases or by primary invasion cancer, were treated. Peridural catheters were inserted and fixed at various levels, thoracic or lumbar, and 50 mg labetalol was injected every 4 h at the beginning and every 12-24 h on the following 2-3 days. The analgesia started immediately during the injection. No sensitive damage or neurovegetative block appeared. In 40% of the patients the catheter was removed after a 3-day treatment because of the definitive suppression of pain. Other analgesics were not required during the treatment; no tolerance to the drug was developed. The peridural catheter remained in situ for an average period of 4-30 days. Afterward it was possible to treat more cases as outpatients depending on their general conditions and with the help of their family doctors. After a few days of therapy, almost all the patients reported a burning pain at the site of the injection; this problem was easily resolved by prior injection of a 4-mg dose of betamethasone.

Analgesics↗
PubMed1982

Radionuclide angiocardiographic assessment of pulmonary vascular reactivity in patients with left to right shunt and pulmonary hypertension.

Radionuclide angiocardiography was used to assess pulmonary vascular reactivity in eight patients (nine studies) with a large, relatively unrestrictive intracardiac defect and pulmonary arterial hypertension. Radionuclide angiocardiograms, using technetium-99m pertechnetate, were performed first with the patient breathing room air and then after 10 minutes of breathing a mixture containing 90 percent or more of oxygen. The pulmonary to systemic flow ratios obtained by gamma variate analysis of the radionuclide time-activity curves were compared with those calculated with the Fick principle at the time of cardiac catheterization. There was a good correlation between the two methods both in room air studies (r = 0.88) and in those obtained with 90 percent or more of oxygen (r = 0.94). All six studies (in five patients) with a reactive pulmonary vasculature (judged by a pulmonary vascular resistance at cardiac catheterization of less than 6 units/m2 with oxygen or after tolazoline) had a radionuclide pulmonary to systemic flow ratio of 3.0 or greater with oxygen. The three patients with a nonreactive pulmonary vasculature had a radionuclide pulmonary to systemic flow ratio of 2.3 or less with oxygen, a value that was unchanged from the room air value. These data suggest that radionuclide angiocardiography may be a useful, relatively noninvasive method of assessing pulmonary vascular reactivity in patients with a large, relatively unrestrictive intracardiac defect.

Angiocardiography↗
PubMed1982

The infant with possible biliary atresia: evaluation by ultrasound and nuclear medicine.

Twenty-eight infants with jaundice were evaluated with ultrasound and radionuclide scans. Comparison of these studies with pathologic, surgical and clinical examinations demonstrated good correlation between ultrasonic and radionuclide studies. Ultrasound is an important preliminary study in the workup of such patients. Combined imaging provides the most information in a patient with suspected biliary atresia.

Bile Ducts↗