Immunodeficiency following human marrow transplantation: in vitro studies.
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Bone Marrow Transplantation↗
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Results for “Human In Vitro Studies”
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In vitro steroid metabolic studies in human testes. II: Metabolism of cholesterol, pregnenolone, progesterone, androstenedione and testosterone by testes of an estrogen-treated man.
The effect of long-term in vivo estrogen treatment on in vitro steroidogenesis by the testes of a young man was investigated. In vitro incubation of testicular tissue of this man with 3H-pregnenolone, 3H-progesterone, 3H-androstenedione and 3H-testosterone demonstrated suppression of 17-hydroxylase activity, with little or no effect of the treatment on delta5-3beta-hydroxysteroid oxidoreductase, 5alpha-reductase and aromatase. Increased 20alpha-hydroxysteroid oxidoreductase activity was observed. Determination of intratesticular steroid concentrations led to similar conclusions.
Adult↗
[Bactericidal action of modified cavity varnishes--their action against microorganisms found in the human oral cavity (in vitro study)].
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Actinomyces↗
An in vitro method for study of human lymphocyte cytotoxicity against mumps-virus-infected target cells.
A chromium release assay was used to study lymphocyte-mediated cytotoxicity against mumps virus-infected target cells in vitro. Purified lmyphocytes from randomly selected donors killed significantly more virus-infected Vero cells than non-infected cells. Lymphocyte-target cell ratios of 50 to 100:1 and incubation period from 16 to 20 hr were optimal for determination of cytotoxicity. The lymphocyte induced chromium release was not obviously correlated with serum mumps hemagglutination-inhibition titers of the effector cell donors. However, the lymphocyte reaction against virus-infected target cells seems to have an immunologic basis. Thus, the more pronounced susceptibility of mumps-infected target cells as compared to non-infected cells was not due to a cytocidal effect of the virus, since spontaneous isotope release from both target cells was the same. Also, cord blood lymphocytes which had exhibited good cytotoxicity when induced either with phytohemagglutinin or with antiserum against target cell antigens were not cytotoxic for mumps-infected Vero cells. Moreover, the lymphocyte reaction against virus infected target cells could be inhibited by high concentrations of hyperimmune rabbit antimumps sera. On the other hand, lower concentrations of antisera specifically poteniated the lymphoycte-mediated isotope release from mumps-infected target cells.
Animals↗
The kinetics of iron uptake in vitro by human duodenal mucosa: studies in normal subjects.
1. A method for determining initial rates of unidirectional radio-Fe uptake from a ferric chelate of nitrilotriacetic acid by human duodenal biopsy specimens in vitro has been devised. [57Co]cyanocobalamin was used as an extracellular fluid marker, and was shown to give results in close agreement with other markers. 2. Uptake was linear for up to 20 min and exhibited saturation kinetics over the concentration range 18--450 mumole/1. 3. In the presence of 2:4 dinitrophenol and fluoride, uptake was reduced by approxi-50%, indicating dependence on metabolic energy. 4. Uptake of Fe was markedly diminished at reduced incubation temperatures, demonstrating a high activation energy for the uptake process. 5. Many of the criteria for the demonstration that the initial uptake of Fe depends on an active transport mechanism have been fulfilled. 6. The apparent distribution volume of 14C-labelled nitrilotriacetate chelate did not exceed the extracellular fluid space, suggesting that Fe is transferred to specific receptors on the enterocyte. The findings are discussed in relation to the possibility that uptake may be a rate-controlling step for the regulation of net intestinal absorption of Fe in man.
Biological Transport, Active↗
[Certain structural details of developing in vitro human embryonal brain explants studied with the aid of fluorescence and scanning electron microscopy].
The bundles growing away from the explants were mainly formed by neuroblast processes. It has been shown that the degree of differentiation of neuroblasts depends on "the age" of embryonal brain. The bundles of neuroblasts are accompained by slightly differentiated cells, having their own processes descending to the surface of the lining. These processes attached to the surface of a bundle cover and have no connection with the inner structures of the bundle. The use of a scanning electron microscopy allows to detect some new details of the behaviour of nerve cells in vitro.
Brain↗
[Spectral sensitivity of the human ERG in-vitro, a study of the photopic component (author's transl)].
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Electroretinography↗
[Pentose phosphate pathway and nucleic acid synthesis in human funicular tissue. In vitro studies].
Umbilical cord slices were incubated with either 1- or 6-14C-glucose, the radioactivities of which were measured in CO2 evolved. The ratio, 1 CO2/6 CO2 was low, being comprised between 1 and 2. Furthermore, this incubation of cord slices with tritiated uridine or thymidine resulted in very low incorporations, especially for the latter. Therefore, both the pentose phosphate pathway and the synthesis of nucleic acid have a low activity in the cord tissue: these might be signs of senescence in this otherwise fetal organ.
Carbon Dioxide↗
[Chemotaxis of human polymorphonuclear cells in vitro. Study of inflammatory rheumatic diseases].
Sixty-eight determinations of leukocyte chemotaxis were performed in 42 patients suffering from systemic lupus erythematodes (17 cases), rheumatoid arthritis (15 cases) and scleroderma (10 cases). In contrast to the results of others, this study showed a deficiency in only 15 of 42 cases (35.7%). Impairment of chemotaxis was always transitory and demonstrable only during acute phases of disease. Intrinsic deficiency of PMN leukocytes as well as deficiency of plasma factors were related to the clinical and biological course of the disease and to the treatment.
Antibodies, Antinuclear↗
The use of thymidine-2-C14 in the study of human gingiva in vitro.
Human gingival explants were cultured for 1 or 2 days in a natural medium without serum. After 1 day in vitro the explants were partly encircled by epithelium which had proliferated from the cut edges of the explant and from rete ridges near the cut edge (epiboly). There was also some cell division in the cells of the spinous layer, and a thick parakeratotic layer had developed. These areas of proliferation were disclosed by the uptake of thymidine-2-C14 by the epithelial cells. Degenerative changes were also evident after 1 day in vitro. This began as hydropic degeneration in the spinous layer of the epithelium and resulted in almost total acantholysis and desquamation of the spinous layer after 2 days in vitro. The addition of serum to the medium might have promoted more epithelial proliferation and delayed the degeneration. The use of thymidine-2-C14 in the medium was an effective method of labeling the active epithelial cells.
Carbon Radioisotopes↗
Amikacin: in vitro bacteriological studies, levels in human serum, lung and heart tissue, and clinical results.
The amikacin sensitivity of bacteria cultured from 3282 clinical cases of mixed type was determined. Gentamicin and amikacin were equally effective against E. coli strains. Amikacin inhibited the growth of more Pseudomonas aeruginosa strains than did gentamicin. Against Gram-positive bacteria gentamicin proved to be more effective. Many of the gentamicin-resistant strains were sensitive to amikacin. Amikacin levels were measured during 21 pulmonary and 14 heart operations, subsequent to a intramuscular administration of 500 mg amikacin. The serum contained 17-20 microgram/ml amikacin, in the intact, inflamed and tumourous parts of removed lung tissue 9, 6 and 6 microgram/g concentrations were detected, respectively, whereas the cardiac auricle and the pericardial fluid contained 3-4 and 2-4 microgram/ml, respectively. These amikacin levels reach or in most cases even exceed the minimal inhibiting concentrations against the bacteria. Therefore, amikacin is excellent for the treatment of respiratory infections, pericarditis and endocarditis caused by Gram-negative, gentamicin-resistant bacteria. Amikacin treatment of 8 patients with grave diseases as well as the successful local administration of amikacin based on the therapy of 55 cases of surgical suppurations is reported.
Amikacin↗
Leaching of chrysotile asbestos in human lungs. Correlation with in vitro studies using rabbit alveolar macrophages.
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Animals↗
[Human fetal antehypophysis in vitro. II. Immunocytological study and radioimmunoassay of LH and FSH (author's transl)].
Human fetal antehypophysis (16 males, 16 females and 4 unknown sex) were cultivated during several weeks. By immunocytochemistry LH gonadotroph cells were determined with anti-hTSH and anti-pLH serum. The release in vitro of LH and FSH was studied by radioimmunoassay. At the first medium change, the quantity of LH and FSH release was related to the gestational age and sex. A rapid decline of both LH and FSH occured over the 10 first days. There after, a basal release of LH was maintained during several months; the release of FSH was generally maintained at the lower limit of the assay. After 1 month in vitro, the level of LH could not be related to the sex. Release of LH was stimulated by synthetic LRF. A significant increase was observed independently of the sex and age of the fetuses studied.
Culture Techniques↗
Prolactin-releasing and release-inhibiting factor activities in the bovine, rat, and human pineal gland: in vitro and in vivo studies.
The effects of crude extracts of bovine, rat, and human pineal glands on prolactin (PRL) release were studied using an in vitro system. In addition, the effects of a known pineal constituent, arginine vasotocin (AVT), and crude bovine pineal extract (bPE) on PRL secretion were studied in vivo. Normal male rat hemipituitaries (HP), incubated with bPE (13 mg tissue/HP)released 200%, 150%, and 285% more PRL into the medium than did their corresponding untreated control halves incubated in either Medium 199 alone, hypothalamic extract, or cerebral cortical extract, respectively. HP incubated with either rat (6 mg of tissue/HP) or human (25 mg of tissue/HP) pineal extract released 110% and 75% more PRL, respectively, than did their corresponding untreated control halves. HP exposed to 10 mg tissue eq of either bovine pineal fraction A1 or bovine pineal fraction A3 released 88% and 63%, respectively, less PRL than did their corresponding untreated control halves incubated in Krebs-Ringer Bicarbonate (KRB) medium. Quantitites of melatonin, thyrotropin-releasing hormone (TRH), or estrogen, comparable to those found in the pineal, had no significant effect on PRL secretion in vitro. The iv injection of either bPE (90 mg tissue/rat) or AVT (10 mug/rat) into estrogen and progesterone-treated male rats resulted in a 40% and 138% increase, respectively, in plasma PRL titers, 10 min after injection, over pre-injection control levels. The per cent of increase in plasma PRL levels in these animals was significantly greater than that observed in control rats receiving either saline or cortical extract. The results suggest that crude extracts of pineal glands of three different species contain prolactin-releasing factor (PRF) activity which is probably not due to any endogenous melatonin, TRH, or estrogen that may be present. Conversely, two bovine pineal fractions, A1 and A3, appeared to exhibit prolactin-inhibiting factor (PIF) activity. We have concluded that the pineal gland may serve as an alternate or supplemental source of PRF and/or PIF.
Aged↗
Autoradiographic in vitro studies on diurnal variation in human epidermal cell proliferation.
Five men with healthy skin ranging in age from 24 to 37 years were investigated for the presence of diurnal variation in epidermal cell proliferation by the in vitro 3H-thymidine labeling technique. The following parameters were studied: The basal cell LI; the numbers of labeled basas and supra-basal cell nuclei as well as the total number of labeled nuclei situated above a basal membrane length of 100 mum. All autoradiographic parameters showed marked diurnal variations, the amplitudes of which differed individually. The basal 3H labeling index always showed the highest diurnal variation. In all patients diurnal variations of the basal and suprabasal cell proliferation occurred simultaneously and in equal direction. However, each test person showed maxima and minima of epidermal DNA synthesis at different times. No synchronism could be found when comparing the individual variations of cell proliferation. Several possible reasons for the asynchronous in vitro behaviour of epidermal cells will be discussed.
Adult↗
Cell replication and aging: in vitro and in vivo studies.
The relationship between human aging and cell replication has been investigated using two complementary approaches: in vitro studies of human fibroblasts derived from young and old volunteer members of the Baltimore Longitudinal Study and in vivo examinations of bone marrow cell populations from young and old mice and rats. Total proliferative capacity measured as either the onset of cell culture senescence or as in vitro life span was significantly diminished in cell cultures derived from old human donors when compared to parallel cultures established from young donors. Acute replicative abilities as measured by percent replicating cells, cell pupulation doubling time, cell number at confluency, and colony size distribution were also significantly decreased in human old cell populations. An in vivo cytogenetic technique for measuring cell replication was developed utilizing the differential staining properties of metaphase chromosomes of cells that have replicated in the presence of bromodeoxyuridine. With this technique, cell cycle times have been derived in vivo as well as in vitro. Preliminary in vivo results in both mice and rats indicate that cell replication is slowed in old animal cell populations. Further research will be directed both in vitro and in vivo at discerning the mechanisms for this impairment of cellular replication with aging.
Adult↗
[In vitro studies on the caries reducing effect of glycerophosphate. 2. Studies with dentin of human teeth].
In vitro experiments on the reduction of the solubility of human dentine in decinormal lactic acid have shown that, under the experimental conditions chosen, disodium beta-glycerophosphate was less efficient than sodium fluoride alone or in combination with ammonium metavanadate and/or ammonium molybdate.
Dental Caries↗
[Studies on the mechanical resistance of human erythrocytes under in-vitro conditions].
Hemolysis and resistance of erythrocytes were studies in-vitro in experiments on human ACD fresh blood and on heparinized fresh blood after oxygen dispersion, resp. mixed oxygen and carbon dioxide dispersion, and subsequent treatment in the hemoresistometer. Blood alkalinity increases under oxygen dispersion, acidity increases under dispersion with mixed gases. The length of the period of dispersion is more important for hemolysis than the change of pH. The hematocrit value influences the behavior of blood resistance. High values imply enhanced hemolysis. There is no significant difference of actual hemolysis values between oxygen and oxygen/carbon dioxide dispersion. A different behavior appears in the calculation of difference value of hemolysis after treatment in resistometer and the respective actual hemolysis.
Blood Preservation↗