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At least 19 recordsLinked to original sources
PubMed1977

Oxygen affinity of duck blood determined by in vivo and in vitro technique.

Half saturation partial pressure of O2,P50, was determined in domestic Muscovy ducks (Cairina moschata) both by in vivo and in vitro techniques. For in vivo determination, blood samples were drawn from the anesthetized, artificially ventilated animals and analyzed both for O2 content, Co2, and O2 partial pressure, Po2. O2 capacity was detemined in arterial samples during hyperoxic ventilation (arterial Po2 about 180 torr). P50 was calculated from measurements in venous blood samples (O2 saturation near 50%). For in vitro determinations, Co2 was measured in blood samples equilibrated with Po2 close to P50. No significant difference was found between P50 values determined by both techniques. At 41 C and pH 7.50, P50 averaged 41.7 torr when analyzed by in vivo technique and 41.4 torr when determined in vitro. The variability between animals was less than 1 torr (SD) and could be explained by the experimental error. The partially discordant literature data on P50 of duck blood are reviewed and critically discussed.

Animals↗
PubMed1976

Preliminary studies on the response of Plasmodium falciparum to chloroquine in the Philippines, with the in vitro technique.

Previous investigations had shown that resistance to standard regimens of chloroquine occurred in some cases of falciparum infection in the Philippines. More extensive investigations into this phenomenon were planned by the Malaria Eradication Service, by means of the in vitro technique developed by Rieckmann, in order to determine both the distribution of resistant strains throughout the country and their local incidence. Before these studies were undertaken, a series of observations were made on cases of falciparum malaria encountered in Manila and its environs, to assess the reaction of local strains of the parasite to the in vitro test. These cases were also treated with standard doses of chloroquine and some were followed up for 4 weeks to compare the predictions made as a result of the in vitro tests with the in vivo observations. Of the 34 in vitro tests carried out, 18 were followed up in vivo. In 8 cases, no recrudescence occurred, but in the other 10 recrudescences were detected during the 4-week observation period, thus indicating parasite resistance to the drug. In each of the 18 cases, the in vivo response followed the in vitro prediction.

Chloroquine↗
PubMed1992

The INVITTOX Data Bank of in-vitro techniques in toxicology.

The dissemination of information about methods in in-vitro toxicology is subject to a number of constraints which are identified and discussed, as are the ways in which INVITTOX seeks to address these problems. The continued interest of scientists in INVITTOX suggests that a real gap in information provision is being filled.

Animals↗
PubMed1976

Differential effects of nephrotoxic agents on renal transport and metabolism by use of in vitro techniques.

A number of studies by the author and other investigators are reviewed in which the in vitro kidney slice technique has been used to evaluate the nephrotoxicity of various compounds. The kidney slice technique can be used to determine the effect of prior drug treatment of laboratory animals on renal organic acid (p-aminohippurate) or organic base (N-methylnicotinamide) transport, on glucose synthesis, and on oxygen consumption by renal coritical slices. The nephrotoxic agents uranyl nitrate and potassium dichromate exert inhibitory effects on renal function, althouhg both agents enhance organic base transport at low doses and potassium dichromate enhances organic acid transport at moderate doses. Enhanced PAH transport has been found to be a sensitive indicator of gentamicin induced nephrotoxicity, while inhibition of other parameters has been reported. The tissue slice method is less effective in evaluation chronic nephrotoxicity such as that produced by lead. The inhibitory effect of mercurial diuretics has been shown to be due to the general depression of metabolic activity by mercury. The kidney slice technique has been found to be a sensitive indicator in the assessment of halogenated hydrocarbon-induced nephrotoxicity. Differential effects of compounds on in vitro organic acid and base trasport provides information about the transport of these compounds as well as about their nephrotoxicity. Although it is often desirable to perform in vivo tests or other in vitro renal function tests, the kidney slice technique has proved to be extremely useful in toxicological evaluations.

Animals↗
PubMed1979

[In-vitro-technique for autoradiographic investigations of cell proliferation in benign and malignant alterations of the human urinary bladder mucosa from biopsy specimens (author' transl)].

An in-vitro double labelling technique with 3H- AND 14C-Thymidine was applied to biopsy specimens of the human urinary bladder mucosa in order to determine proliferation kinetics of normal bladder epithelium as well as its benign and malignant alterations. Application of above mentioned technique led to evaluable autoradiographs. The mean 3H-Thymidine labelling-index in bladder cancer was remarkably higher than in normal bladder epithelium and in benign papillomas. There was a good correlation between histologic grading of malignancy and increase of the mean 3H-Thymidine labelling index. Addition of 5-Fluorodesoxyuridine to the incubation medium had no influence on the labelling of the incubated tissue.

Autoradiography↗
PubMed1975

Tritiated thymidine uptake in pig skin. Comparison of in vivo and in vitro techniques.

Tritiated thymidine (3HT) was used in one of three ways to label deoxyribonucleic acid replication in epidermal cells of miniature swine: (1) the radioactive material was injected intracutaneously in vivo; (2) the radioactive material was injected intracutaneously into biopsy specimens and the specimens incubated in vitro in Eagle's medium, or (3) uninjected biopsy specimens were incubated in Eagle's medium with added 3HT. The first two methods yielded the same proportions of labeled cells with uniform distribution of labeled cells. The third method resulted in labeling of cells mainly at the periphery of the biopsy specimens. The advantages of the in vitro over the in vivo technique of injection of 3HT includes the fact that injecting a biopsy specimen avoids the problems of large amounts of radioactive waste disposal in animal studies or the legal and ethical problems of tracer studies in humans.

Animals↗
PubMed1978

An in-vitro technique for studying fleece-rot and fly strike in sheep.

Fleece-rot was experimentally induced in-vitro by wetting and incubating Merino wool samples embedded in serum-agar. Gravid Lucilia cuprina were readily-attracted to these wool culture plates to oviposit. Where serum was freely available to newly-hatched larvae, fly strike and larval development ensued. Using this technique, fleece-rot and oviposition were found to be markedly influenced by the availability of protein and by bacterial activity, particularly that of Pseudomonas spp. The results indicated that odours emanating from wool culture plates containing the latter species played an important role in oviposition. Furthermore, these events varied according to the type of fleece selected, and could be prevented by the addition of a bactericide.

Animals↗
PubMed1992

An assessment of the flow rate within peritoneal dialysis catheters, using a standardized in vitro technique.

A variety of peritoneal dialysis catheters are used in clinical practice. The catheters are mainly described by their design, French number (circumference in mm) and length. However, this description does not provide information about the catheters inflow and outflow rates. We have therefore, studied flow rates of 18 adult catheters, using a uroflowmeter. Inflow rates were measured with the inflow bag 100 cm and 145 cm above the tip of the catheter, and outflow rates were measured with the flow transducer located 35 cm and 80 cm below the tip of the catheter, imitating situations where patients are sitting in a chair or laying in a bed during fluid exchanges. Ten measurements were made for each catheter at all heights. We found that catheter designs do affect flow rates. Straight catheters had statistic significantly faster inflow and outflow rates compared to curled catheters (p < 0.001). Moreover, curled catheters had statistic significantly faster flow rates than Swan Neck catheters (p < 0.001). The length and internal diameter of the catheter was found to be the determining factor for the differences in flow rates.

Catheterization↗
PubMed1975

A comparison of secondary palate development with different in vitro techniques.

Palatal processes from 14-day fetal C57BL mice were cultured under varying conditions for 48 hours and prepared for light and electron microscopy. Disruption of the epithelium along the medial border occurred when single palatal processes were explanted onto Millipore filters, plasma clots, or lens paper in subjacent contact with nutrient medium. Paired processes under the same culture conditions demonstrated typical midline epithelial disruption and mesenchymal fusion. Regions of mesenchymal necrosis occurred in processes grown on nutrient agar in a dish or submerged in nutrient medium. In similar cultures medial epithelial disruption did not occur in single processes and mesenchymal fusion of paired processes was either delayed or did not occur. Disruption of the epithelium along the medial border in single palatal processes, and mesenchymal fusion in paired palatal processes, occurred when palates were grown on nutrient agar supported above but in contact with nutrient medium. The results indicated that responses of palatal epithelium and mesenchyme may be altered by different in vitro procedures. These observations emphasize that many factors must be considered in interpreting developmental changes in palatal processes grown in vitro.

Agar↗
PubMed1979

Biochemical aspects of muscle differentiation as analyzed by in vitro cultivation techniques.

Myoblasts cultivated in vitro will undergo terminal differentiation to form muscle fibres. Teratoma derived mouse cell lines, a pluripotent primitive line, and a muscle cell line, provide a possibility for comparing RNA populations in an early precursor cell with those in committed myoblasts and differentiated myotubes. Molecular hybridization analyses led to the conclusion that new RNA sequences appear in the cytoplasm during muscle differentiation. Such muscle specific sequences are not detectable in the nuclear RNA of myoblasts or primitive cells. Studies of protein synthesis during terminal myogenesis indicate co-ordinate expression of the muscle contractile proteins. These represent distinct isozymes, distinguishable from the contractile proteins of other cell types. In the case of myosin light chains isozymic transitions between different muscle forms have been identified during early development.

Animals↗
PubMed1992

Impact of in vitro fermentation techniques upon kinetics of fiber digestion.

Three in vitro fermentation experiments were conducted to examine the impact on kinetics of fiber digestion of microminerals and tryptone addition, media reduction, fermentation vessel, CO2 gassing regimen, and buffer type. Alfalfa and bromegrass hays were incubated for 0, 4, 8, 12, 18, 24, 30, 36, 48, 72, and 96 h and analyzed for NDF. Kinetic measures of fiber digestion were estimated using nonlinear regression with iteratively reweighted least squares. In Experiment 1, continuous CO2 gassing increased rate and decreased lag time prior to NDF digestion compared with purging a non-CO2-saturated buffer at inoculation. Vessel type (50-ml polypropylene tube, 125-ml pyrex Erlenmeyer flask), use of additives (microminerals, tryptone), and media reduction had no effect on kinetics of NDF digestion. In Experiment 2, elimination of both media reduction and nutritive additives increased the lag time prior to NDF digestion. In Experiment 3, continuous CO2 gassing of buffer in 125-ml Erlenmeyer flasks resulted in faster rates of NDF digestion than CO2-saturated buffer in 50-ml screw-cap polypropylene tubes. The method that yielded the fastest rates and shortest lag times of NDF digestion consisted of continuous CO2 gassing, reduction, and use of additives to ensure that no nutrient limited fiber digestion.

Animals↗