ABSTRACT
A procedure for the determination of cerebral blood flow by the local clearance method after intracarotid injection of 133Xe in the conscious rabbit is described. The inert radioactive indicator is injected into a permanent nylon catheter equipped with a two-way Gordth's needle inserted into the common carotid artery and filled with heparin, emerging behind the shoulders of the animals. All branches of the homolateral common carotid artery except the internal carotid artery were ligated. Studies of the distribution of colored tracers (dark blue ink) and radioactive tracers (99mTc albumin microspheres) show that the main localization of the injected indicator is within the homolateral hemisphere. Brain to blood partition coefficients of 133Xe are worked out for rabbit's gray matter (0.576 +/- 0.048) and white matter (0.808 +/- 0.023). The slope method for first and second component of the wash-out Xenon curve is used for CBF calculations. CBF determinations in 9 normal rabbits result in 84.27 +/- 5.59 and 16.69 +/- 2.44 ml/min x 100 g tissue, respectively, for the fast and slow component. Significant changes do not occur in serial determinations within 2 hr.
Subject(s)
Cerebrovascular Circulation , Anesthesia , Animals , Brain/diagnostic imaging , Carotid Arteries , Injections, Intravenous , Methods , Microspheres , Rabbits , Radionuclide Imaging , Technetium , Time Factors , Xenon RadioisotopesSubject(s)
Radiometry , Humans , Occupational Medicine , Radiation Dosage , Radiation Effects , Radiation Protection/standards , SafetyABSTRACT
Lymphocytes were isolated from rectal biopsies and resected gut specimens through a simple mechanical technique, and assayed for T-cell quantitation and mitogenic response to PHA and PPD. T-cells were found in considerable numbers in gut mucosa of all groups, but in each case their percentage was lower than that of the autologous peripheral blood. The mitogenic response to PHA was found in general to be lower in the mucosal lymphocytes compared to those in blood, with the exception of the polyposis group which responded highly. No response of mucosal cells to PPD was seen. Inhibition studies done by means of mixed cultures revealed the presence of a suppressor activity in many mucosal lymphocytes, especially in the inflamed mucosa group, which may partly account for some low responses observed with mucosal lymphocytes. Further studies are under way to better define these quantitative and functional differences seen in gut mucosal cells, and to correlate differences with disease states.
Subject(s)
Intestinal Mucosa/immunology , T-Lymphocytes/immunology , Humans , Intestinal Diseases/immunology , Intestinal Neoplasms/immunology , Lymphocyte ActivationABSTRACT
Accumulation of 99m Tc-Sn-pyrophosphate in pleural effusions has been evaluated in 56 patients grouped as follows: 8 with bacterial effusion (Group A), 27 with malignant effusion treated by local and/or parenteral antitumor chemotherapy (Group B), 21 with malignant effusion treated only by supportive therapy (Group C). Results, expressed as effusion to plasma PPi ratio, ranged from 0.1 to 0.28 in group A, from 0.04 to 0.64 in group B and from 0.60 to 1.73 in group C, with significant differences among the three groups. In no case was uptake found in cells of the sediment. Chemical analysis (including total and ionized calcium, total protein, acid and alkaline phosphatase) of plasma and exudate in neoplastic patients showed a slight, but significant, difference between groups B and C as regards plasma-effusion gradient for total calcium and acid phosphatase. Negative correlation also exists between effusion to plasma PPi ratio and plasma-exudate gradient for ionized calcium in neoplastic patients. The data support the hypothesis that acid phosphatase content and calcium gradient are among the factors involved in the mechanism of PPi accumulation in pleural effusions.
Subject(s)
Pleural Effusion/diagnostic imaging , Technetium , Diphosphates , Humans , Pleural Neoplasms/diagnostic imaging , Radionuclide Imaging , TinSubject(s)
Central Nervous System Diseases/diagnosis , Indium , Pentetic Acid , Radionuclide Imaging , Serum Albumin, Radio-Iodinated , Adult , Child , Humans , RadioisotopesSubject(s)
Adrenal Cortex Hormones/blood , Adrenocorticotropic Hormone/blood , Noise , Adult , Electroencephalography , Humans , MaleABSTRACT
Human embryo fibroblast cell cultures (RU-I) infected with virulent and attentuated strains of rubella virus of treated with a cell extract form infected and from control cultures have been studies in respect of their mitotic activity by evaluating the (3-H) thymidine uptake by autoradiography. The results show the presence in infected cell cultures of a nonvirionic inhibitor of DNA synthesis, which is detectable in control cell cultures too, though to a lesser degree. The relation of this inhibitor to the chalone system is so far unclear. No effect of the extracts on human chromosome pattern was observed. Attempts of biochemical characterization by fractionation of 14-C-labeled extracts on polyacrylamide gel followed by autoradiography were unsuccessful.
