ABSTRACT
The active potential difference across bovine corneal endothelium was measured in vitro at different temperatures, pH, osmolality and salt compositions. The measurements were made using either identical or different solutions on each side of the membrane. The experimental results are consistent with a model in which sodium is actively transported into the intercellular cleft. We propose that Na+ re-enters the cell electroneutrally by coupled co-transport with carbonate, derived from bicarbonate in the solution.
Subject(s)
Cornea/metabolism , Ion Channels/metabolism , Action Potentials/drug effects , Animals , Bicarbonates/metabolism , Cattle , Cornea/physiology , Culture Media , Endothelium/metabolism , Endothelium/physiology , Hydrogen-Ion Concentration , Membrane Potentials/drug effects , Osmolar Concentration , Ouabain/pharmacology , Sodium/metabolism , Sodium Chloride/pharmacology , TemperatureABSTRACT
To study aortic velocities in the fetus, a newly developed multirangegated Doppler velocimeter was combined with a commercial B-mode linear-array apparatus. Spectrum analysis of the Doppler shift signals was performed. The signals with the highest frequencies were selected for hard-copy, and integrated with a digitizer. In the first part of the study, the reproducibility of the method was established by serial measurements of aortic velocity in 7 near-term fetuses. It proved sufficient to evaluate 5 successive heart-cycles. The mean coefficient of variation was 5% (mean number of recordings evaluated 7.5). In the second part of the study, possible influence of aortocaval compression on fetal aortic velocity indicative of changes in fetal cardiac output, was investigated in 10 pregnant women with no symptoms of supine hypotension. Doppler monitoring of the material cardiac output from the suprasternal notch was added to the set-up described to study the supine reduction of cardiac output frequently described in pregnant women. No significant change was found either in the maternal or in the fetal circulation.
Subject(s)
Aorta/physiology , Fetal Heart/physiology , Pregnancy , Ultrasonography , Blood Flow Velocity , Cardiac Output , Female , Fetal Distress/diagnosis , Humans , PostureSubject(s)
Descemet Membrane/metabolism , Animals , Biological Transport, Active , Cattle , Ions , Membrane Potentials , Water/metabolismABSTRACT
This study was performed in order to develop a method for studying blood flow in the ophthalmic circulation. Using a pulsed doppler system utilizing an ultrasonic frequency of 10 MHz, blood flow velocities have been measured in the ophthalmic artery and in the arteries behind the eyeball (lateral posterior ciliary arteries) in 40 normal subjects. The mean of the peak systolic velocities were 34 +/- 6 cm/s in the ophthalmic artery, and 14 +/- 3 cm/s in the lateral posterior ciliary arteries. We conclude that blood flow velocities can be measured in defined vessel areas in the orbit.
Subject(s)
Eye/blood supply , Ultrasonography , Adolescent , Adult , Age Factors , Blood Flow Velocity , Ciliary Body/blood supply , Doppler Effect , Humans , Middle Aged , Ophthalmic Artery , Orbit/blood supply , Regional Blood FlowABSTRACT
Uraemic plasma and normal serum were separated into fractions of different molecular sizes by means of molecular filtration through Pellicon filters and liquid chromatography on Sephadex G-15. The amount of substance was considerably higher in uraemic fractions than in comparable normal fractions. When normal human mononuclear phagocytes were cultured in the presence of the uraemic fraction containing the largest molecules, detachment of phagocytes from the glass coverslips was significantly increased. The digestion capacity of the remaining cells was decreased. The results indicate that substances in uraemic plasma responsible for the impaired function of human mononuclear phagocytes cultured in vitro consist of molecules of a molecular weight higher than 10 000.
Subject(s)
Monocytes/drug effects , Phagocytosis/drug effects , Toxins, Biological/pharmacology , Uremia/blood , Candida albicans , Cells, Cultured , Chromatography, Gel , Humans , Micropore Filters , Molecular WeightABSTRACT
In a study of 37 leprosy patients, the oral administration of levamisole failed to provoke an increase in both the Fernandez and Mitsuda reactions to lepromins of human and armadillo origin. We interpret this as evidence against an effective specific immunostimulatory capability of levamisole in leprosy patients under the conditions of the study. Current knowledge of the mechanism of levamisole action supports the concept that the fundamental immunologic defect in lepromatosus leprosy may reside in the lymphocyte and not the macrophage, or the respective related functions of these two cell forms.
Subject(s)
Immunity, Cellular/drug effects , Lepromin/immunology , Levamisole/pharmacology , Adult , Aged , Animals , Armadillos , Humans , Leprosy/immunology , Levamisole/administration & dosage , Lymphocytes/immunology , Mice , Middle Aged , Mycobacterium leprae/isolation & purificationABSTRACT
To assess the usefulness of Mycobacterium leprae-infected armadillo tissue as a substitute for human lepromas for the manufacture of lepromin, we compared skin reactions to preparations from these two sources in 115 leprosy patients. The patient sample represented all the primary clinical forms of leprosy. Lepromin derived from the armadillo (lepromin-A) provoked the same pattern of responses as human derived lepromin (lepromin-H), i.e., lepromatous patients gave the weakest reactions. Lepromin-A reactions were consistently more intense than those to lepromin-H. We conclude that lepromin-A is a promising alternative to lepromin-H and may make the worldwide distribution of a standardized skin testing reagent feasible.
