Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “In Vitro”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1985

Testing of 24 food, drug, cosmetic, and fabric dyes in the in vitro and the in vivo/in vitro rat hepatocyte primary culture/DNA repair assays.

Twenty-four dyes currently or previously used in the food, drug, cosmetic, and textile industries were tested in the in vitro rat hepatocyte primary culture/DNA repair (HPC/DR) assay and, to a limited extent, in the in vivo/in vitro HPC/DR assay. The positive control, Solvent Yellow 3 (o-aminoazotoluene), and five other dyes (4-dimethylaminobenzeneazo-1-naphthalene, 4-dimethylaminobenzeneazo-2-naphthalene, Direct Blue 53, Acid Blue 9, and 4-dimethylaminostilbene) induced DNA repair in rat hepatocytes both in vitro and in vivo, while 13 of the dyes (Food Red 1, Food Red 5, Food Orange 4, Food Red 7, Acid Red 14, Acid Red 27, Pigment Red 53, Acid Yellow 23, Food Black 1, Food Green 3, Acid Red 51, Acid Blue 74, and Natural Red 4) did not produce any detectable DNA repair in either the in vitro or in vivo/in vitro assays. Direct Blue 14 had weak activity in vitro but none was detected in vivo. In contrast, Solvent Yellow 5 was not active in vitro, but produced a weak positive response in vivo. Negative responses were also obtained for Solvent Yellow 14 and Acid Green 5 in the in vitro assay, whereas the responses produced by these dyes in the in vivo/in vitro assay were judged to be equivocal. An equivocal response was also obtained for Direct Red 28 in the in vivo/in vitro assay as well as in the in vitro assay. These findings provide information about the potential genotoxicity of a number of dyes for which previous genotoxicity data has been inconsistent or inadequate. For some dyes (eg, Solvent Yellow 5), discrepancies between the results obtained in the in vitro and in vivo/in vitro assays may implicate a role for intestinal microflora in their metabolic activation.

Animals↗
PubMed1994

Differences in pronucleus formation and first cleavage following in vitro fertilization between pig oocytes matured in vivo and in vitro.

To elucidate the developmental differences occurring after in vitro fertilization (IVF) of pig oocytes matured either in vitro (n = 1934) or in vivo (n = 1128), the present experiment investigated the morphological changes from penetration to the two-cell stage. Oocytes were examined every 2-4 h from 2 to 32 h after in vitro insemination to study sperm penetration, male and female pronucleus formation, synkaryosis and first cleavage. The penetration rate was significantly higher (P < 0.05) for in vivo matured oocytes (69.8%) than for in vitro matured oocytes (35.0%). Penetration of spermatozoa into the ooplasm was first recorded 6 h (in vitro matured oocytes) and 4 h (in vivo matured oocytes) after addition of the spermatozoa to the oocytes. For both in vivo and in vitro matured oocytes, 2 h were required for sperm head decondensation. However, maximum sperm head decondensation occurred 2 h later in in vitro matured oocytes. Within 6 h, 41.7 +/- 5.6% of the in vivo matured oocytes had completed second meiotic division, whereas only 20.8 +/- 6.5% of the in vitro matured oocytes reached this developmental stage (P < 0.01). For in vitro matured oocytes, male pronucleus formation was retarded 2-4 h after onset of insemination and development of the female pronucleus was enhanced compared with in vivo matured oocytes. Synchronized opposing pronuclei were observed 14 h after insemination in in vitro matured oocytes and after 8 h in in vivo matured oocytes. Synkaryosis was first observed at 16 and 18 h in in vivo and in vitro matured oocytes, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Effect of in vitro irradiation and cell cycle-inhibitory drugs on the spontaneous human IgE synthesis in vitro.

The in vitro effects of radiation, diterpine forskolin (FK), and hydrocortisone (HC) on the in vitro spontaneous IgE synthesis by peripheral blood B-lymphocytes from atopic patients were investigated. Without affecting cell viability, in vitro irradiation inhibited in a dose-dependent fashion de novo IgE synthesis in vitro by B cells from all patients examined with a mean 40% reduction of in vitro IgE product after treatment with 100 rads. In contrast, the in vitro IgE production by the U266 myeloma cell line was unaffected, even by irradiation with 1600 rads. The addition to B cell cultures from atopic patients of FK consistently resulted in a dose-dependent inhibition of the spontaneous IgE production in vitro. The addition to cultures of 10(-5) and 10(-6) molar concentrations of HC was also usually inhibitory, whereas lower HC concentrations were uneffective or even enhanced the spontaneous in vitro IgE synthesis. When 10(-6) molar concentrations of both HC and FK were combined in culture, a summation inhibitory effect on the spontaneous IgE synthesis was observed. In contrast, neither FK nor HC had inhibitory effect on the in vitro spontaneous IgE synthesis by the U266 myeloma cell line. The spontaneous in vitro IgE synthesis by B cells from patients with Hodgkin's disease, demonstrating high levels of serum IgE, was strongly reduced or virtually abolished after patients underwent total nodal irradiation to prevent the spread of the disease. In addition, the in vitro spontaneous IgE synthesis by B cells from atopic patients was markedly decreased or abolished by in vivo administration of betamethasone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Differences in amino acid content of preimplantation mouse embryos that develop in vitro versus in vivo: in vitro effects of five amino acids that are abundant in oviductal secretions.

Although it is now well established that amino acids can improve preimplantation development of mouse embryos in vitro, the mechanisms by which they influence development have not been determined. To investigate these mechanisms, we compared the contents of seven abundant amino acids (alanine, aspartate, glutamate, glycine, serine, and taurine) in 4-8-cell embryos and blastocysts developing in vivo with the contents in those developing from the 2-cell stage in vitro. We also studied the effects of five amino acids (alanine, glutamate, glutamine, glycine, and taurine) that are abundant in the oviductal lumen on the amino acid content of embryos developing in vitro. Blastocysts that developed in vitro contained about six times more alanine and about one-sixth as much taurine as blastocysts that developed in vivo, but the same amounts of glycine and serine. In the presence of glycine and four other abundant amino acids in oviductal secretions, however, blastocysts that developed in vitro had higher levels of both glycine and serine than those that developed in vivo. In contrast, glycine either alone or in combination with the other amino acids reduced the alanine content of blastocysts developed in vitro to nearer that of blastocysts developing in vivo. Similarly, taurine in the medium allowed blastocysts developed in vitro to increase their content of this amino acid to normal levels. The levels of taurine and, somewhat surprisingly, glutamine and glycine became abnormally low in embryos within 24 h of the onset of in vitro culture in medium that did not contain the amino acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1985

Specific antibody synthesis in vitro. III. Correlation of in vivo and in vitro antibody response to influenza immunization in young and old subjects.

Young and elderly volunteers received a trivalent influenza vaccine and blood samples were obtained prior to, 1 week and 3 weeks after immunization. Plasma antibody levels and the capacity for in vitro lymphocyte synthesis of specific anti-influenza antibody were assessed. Additionally, prior to immunization, peripheral blood mononuclear cells were cultured in the presence of antigen, and the capacity for in vitro immunization was determined. Antibody response was therefore measured after in vivo and in vitro immunization. After in vivo immunization, plasma antibody level and in vitro synthesis capabilities were significantly greater in the young subjects, and these assays correlated significantly. The capacity for in vitro immunization was also greater in the young, but the difference did not reach statistical significance and there was no correlation with in vitro immunization potential and the response after in vivo vaccination. Assessment of in vitro antibody synthesis after vaccination however, may prove a useful tool for probing immune deficient states and testing the success, in vitro of various immune reconstitution measures.

Adult↗
PubMed1985

In vitro--in vivo correlation of dissolution, a time scaling problem? Transformation of in vitro results to the in vivo situation, using theophylline as a practical example.

Two principal approaches to demonstrating the continuous in vivo relevance of an in vitro dissolution test are outlined. The first uses the convolution technique to predict the concentration-time course in vivo; the second uses deconvolution as a mathematical tool to estimate the in vivo dissolution profile. The weighting function must be known to utilise either technique. Defined by the aim of the analysis the dose-normalized response to the oral solution is regarded as the weighting function (Impulse Response). In both cases the essential step is continuous comparison of the predicted time dependent data with actual readings of the same class. To permit the prediction of concentration-time data from in vitro dissolution data the basic equations for the transformation of the time base from in vitro to in vivo conditions are developed. The transformation is essential, since one cannot assume that the time scales for the in vitro and the in vivo experiment are definitely the same. The estimated in vivo dissolution profile using the deconvolution technique gives a hypothetical image of the true in vivo dissolution curve. Comparison with in vitro dissolution test results, using one of the equivalence testing procedures, reveals how closely and for how long the in vitro dissolution test simulates the in vivo dissolution process. For the formulation of theophylline studied, equivalence of the in vitro and the estimated in vivo dissolution profiles was not confirmed for the entire period of observation, but it was demonstrated for approximately the first 5 h. The later inequivalence is not due to possible non-linear or time-dependent kinetics of theophylline. There is a discussion of whether a change in pH, agitation of the formulation, diffusion conditions or the absorption rate constant along the gastrointestinal tract might explain the biphasic linear correlation of the in vitro and in vivo data observed.

Adult↗
PubMed1975

The failure to show a necessary role for C3 in the in vitro antibody response.

The in vitro antibody response of mouse spleen cells to TNP coupled to both T-dependent and T-independent carriers as well as to sheep erythrocytes has been studied to investigate the possible role of complement activation in the induction of antibody formation. The following has been found. (1) In vitro responses of both IgM and IgG can be obtained to both T-dependent and T-independent antigens in serum-free media, although they are smaller than those found in serum-containing media. This shows that no exogenous source of complement is necessary for in vitro antibody formation by spleen cells. (2) Similarly, normal antibody responses are obtained if the cultures are grown in human serum depleted of C3b-inactivator, which contains high concentrations of C3b. (3) In the presence of antibody to mouse C3 the response to the T-independent antigen is reduced, the IgM responses being more affected than the IgG. However, purified F(ab')2 anti-C3 has no inhibitory effect and it therefore seems likely that it is the formation of intact immune complexes containing Fc rather than the interference with C3 function that is responsible for the inhibition seen. (4) The conventionally purified anti-complementary factor from cobra venom has no effect on the antibody response in serum-free culture or when human or fetal calf sera are used. In no experiment was any potentiation of T-dependent responses observed. However, the presence of quite small concentrations (2%) of cobra veno

Animals↗
PubMed1984

Induction of unscheduled DNA synthesis in primary rat hepatocytes by benzidine-congener-derived azo dyes in the in vitro and in vivo/in vitro assays.

The genotoxicity of the benzidine-congener-derived azo dyes. Direct Blue 1 ( DB1 ), Direct Blue 14 ( DB14 ), Direct Brown 95 ( DB95 ), and Direct Red 46 ( DR46 ) was studied in the in vitro and in vivo/in vitro unscheduled DNA synthesis (UDS) assays in primary rat hepatocytes to determine if in vivo metabolism of these compounds was required for induction of UDS. Hepatocytes were isolated, cultured, and treated with the azo dyes and [3H]thymidine (in vitro assay); alternatively, in the in vivo/in vitro assay, rats were intubated with the azo dyes, the hepatocytes isolated at 17 h after dosing and incubated in a medium containing [3H]thymidine. UDS was quantified by an autoradiographic method. None of the azo dyes induced UDS in the in vitro assay. However, DR46 did induce marginal, but significant UDS in 1 experiment (1.2 net grains at 500 micrograms/ml media). No significant UDS was observed when DR46 was tested in a subsequent in vitro assay. In the in vivo/in vitro assay, DB95 (100 mg/kg), DB14 (125 mg/kg), and DR46 (100 mg/kg) induced significant UDS (12, 2.1, and 3.5 net grains, respectively). None of the azo dyes tested was mutagenic in the Salmonella/microsome assay in the presence and absence of rat liver enzymes. Therefore, in vivo reduction of azo dyes, presumably by the gut microflora, is a requirement for the genotoxicity of these azo dyes in the primary rat hepatocyte UDS assay.

Animals↗
PubMed1995

Cysteamine enhances in vitro development of porcine oocytes matured and fertilized in vitro.

Most porcine oocytes matured and fertilized in vitro fail to develop normally due to abnormal fertilization. The aim of this study was to determine the effect of cysteamine on pronuclear formation and developmental competence in pig embryos produced in vitro. Follicular oocytes were matured in vitro with or without cysteamine in Medium 199 supplemented with sodium pyruvate, FSH, LH, 17 beta-estradiol, antibiotics, and 25% porcine follicular fluid. Matured oocytes were then inseminated for 10 h. In the first experiment, pronuclear formation was assessed immediately after the insemination period. The addition of 50 microM or 500 microM cysteamine to the maturation medium increased male pronuclear development, resulting in a higher proportion of oocytes with synchronously formed male and female pronuclei. The frequency of synchronous pronuclear formation was increased in monospermic oocytes from 10% in the control group to 43% (p < 0.001) and 45% (p < 0.001), respectively, and in polyspermic oocytes from 43% in the control group to 68% (p < 0.05) and 75% (p < 0.001), respectively. In the second experiment, development of the in-vitro produced embryos was assessed after 7 days of culture in vitro. The addition 500 microM cysteamine to the maturation medium increased the percentage of cleaving embryos developing to the 8-cell (37% vs. 16%; p < 0.001), morula (19% vs. 6%; p < 0.001), and blastocyst (12% vs. 1%; p < 0.001) stages. These results demonstrate that the addition of cysteamine to maturation medium increases synchronous pronuclear formation and normal embryonic development in porcine oocytes matured and fertilized in vitro.

Animals↗
PubMed1992

In vitro induction of CD8 expression on thymic pre-T cells. II. Characterization of CD3-CD4-CD8 alpha + cells generated in vitro by culturing CD25+CD3-CD4-CD8- thymocytes with T cell growth factor-beta and tumor necrosis factor-alpha.

We previously reported that CD25 (IL-2R p55)-positive CD3-CD4-CD8- murine thymocytes can be induced to express CD8 alpha (Lyt-2) by transforming growth factor-beta plus TNF-alpha in the presence of IL-7 (which is necessary to maintain the viability and differentiation capacity of CD25+CD3-CD4-CD8- thymocytes in vitro). The majority of cells recovered after 2 to 3 days from these cultures expressed CD8 alpha (but not CD3 or CD4). In this study, we have characterized these in vitro generated CD3-CD4-CD8 alpha + thymocytes and compared them with normal CD3-CD4-CD8+ thymocytes. Unlike normal CD3-CD4-CD8+ thymocytes that express CD8 alpha and CD8 beta (Lyt-3-chain) simultaneously, only a fraction of in vitro generated CD3-CD4-CD8 alpha + cells expressed CD8 beta. However, along with the induction of CD8 alpha and CD8 beta expression, the expression of other T cell differentiation markers (including CD2, CD25, and CD44) also changed in a manner corresponding to physiologic differentiation. Cell-surface phenotyping suggests that CD8 alpha + beta - cells are less mature than CD8 alpha + beta + cells. These in vitro generated CD3-CD4-CD8 alpha + thymocytes expanded and differentiated into the CD4+CD8+ stage as well as mature (CD3+) single positive (CD4+CD8-) and CD4-CD8+) stages in fetal thymus organ culture that had been depleted of lymphoid cells by treatment with 2-deoxyguanosine. The latter observation indicates that these in vitro generated CD3-CD4-CD8 alpha + thymocytes are responsive to other differentiation-inducing signals (including those that induce CD4) that exist in fetal thymus organ culture. These results suggest that in vitro generated CD3-CD4-CD8 alpha + thymocytes represent intermediate differentiation stages between CD25+CD3-CD4-CD8- and CD3-CD4-CD8+ cells found in normal thymus.

Animals↗
PubMed1994

In vitro drug testing of ovarian cancer using the human tumor colony-forming assay: comparison of in vitro response and clinical outcome.

The purpose of this study was to assess the prognostic value of in vitro drug chemosensitivity testing using the Hamburger-Salmon human tumor colony-forming assay (HTCA) in fresh tumor samples obtained from newly diagnosed patients with stage II-IV ovarian cancer undergoing maximum cytoreductive surgery and prior to platinum-based chemotherapy. The HTCA was performed on fresh ovarian cancers obtained from 93 patients at their initial exploratory laparotomy to evaluate in vitro sensitivity to cisplatin, carboplatin, and cyclophosphamide following a 1-hr drug exposure. Prospective clinical follow-up was performed on all patients with the primary study endpoints being pathologically proven complete response at second-look surgery and disease-free and overall survival durations. In vitro drug sensitivity was strongly dose-dependent. At a concentration of 5 micrograms/ml only 23% of tumor samples were sensitive (as defined by a > or = 50% decrease in tumor colony-forming units compared to controls) to cisplatin; 13% of tumors were sensitive to carboplatin at a concentration of 50 micrograms/ml and 11% to 4-OH-cyclophosphamide at a concentration of 1 microgram/ml. At doses which were 10 times the previously stated concentrations, the sensitivity rates to cisplatin, carboplatin, and 4-OH-cyclophosphamide increased to 72, 63, and 53%, respectively. Subjects were categorized as having drug-sensitive disease if HTCA results showed in vitro drug sensitivity to at least one of the agents used in their primary chemotherapy. Multivariate analysis failed to show any advantage in clinical response rate, progression-free interval, or survival duration for patients with drug-sensitive disease compared to drug-resistant disease; however, there was evidence of a trend toward an enhanced pathologically proven complete response rate in patients who had chemosensitive tumors in vitro. Second-look surgery was performed in 28 of 55 patients with optimal surgical resections and no clinical evidence of disease at the completion of their primary chemotherapy. Fifty percent (5/10) of patients with drug-sensitive disease achieved a pathologic complete response, while only 3/18 (17%) patients with drug-resistant tumors had a documented pathologic complete response (P = 0.13). As reported in other ovarian cancer studies, patient characteristics which were found to be significantly associated with survival were stage of disease (II-III vs IV), optimal primary surgical resection (i.e., < 1 cm2 residual tumor) vs suboptimal resection, clinical measurability of disease at initiation of chemotherapy, and response to primary chemotherapy. In conclusion, in vitro drug sensitivity, as measured by the HTCA, does not appear to be an independent prognostic factor for survival in patients with stage II-IV epithelial ovarian cancer who undergo standard treatment with tumor debulking surgery and primary platinum-based chemotherapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

The interaction of wheat germ tyrosyl-tRNA synthetase and the tRNA-like end of brome mosaic virus RNA has no effect on in vitro viral protein synthesis and on in vitro encapsidation.

The effect of aminoacylation of the tRNA-like end of brome mosaic virus RNA during in vitro protein synthesis and in vitro viral encapsidation was investigated. The components of the homologous system were: BMV RNA, wheat germ cell-free protein synthesizing system and pure tyrosyl-tRNA synthetase from wheat germ. During in vitro protein synthesis directed with tyrosylated as well as non-tyrosylated BMV RNA, no differences were observed in the amount and in the class of polypeptides formed neither in the velocity of the translation reaction. Excess active TyrRS was added during in vitro translation, without modifying the translation efficiency. BMV RNA and active TyrRS were preincubated prior to translation in order to interact without the translation system components and then subjected to translation in vitro. Similar results were obtained when BMV RNA was preincubated with inactive TyrRS or BSA. These results indicate that the aminoacylation of BMV RNA has no pronounced effect on viral protein synthesis in vitro. During BMV RNA encapsidation either tyrosylated or non-tyrosylated BMV RNA 4 could be encapsidated in a similar way.

Capsid↗
PubMed1989

Inhibition of in vitro and in vivo mast cell degranulation by Taenia crassiceps metacestodes in vitro incubation products.

In vitro released products of T. crassiceps metacestodes (TcIP) harvested from the peritoneal cavity of NMRI mice were tested for inhibitory effects on the in vitro degranulation of peritoneal mast cells (MCs) of normal mice (NMRI) and rats (Wistar) and on the in vivo degranulation of rat (Wistar) skin MCs (PCA-assay). In vitro degranulation was elicited chemically (compound 48/80, polymyxin B or the bee venom peptide, mellitin). In vivo degranulation was triggered immunologically (anaphylactic systems ovalbumin/anti-ovalbumin or Fasciola hepatica crude fluke extract antigen/serum of fluke-infected rats (Wistar]. In vitro degranulation of murine peritoneal MCs or the in vitro histamine release of rat peritoneal MCs normally induced chemically was significantly inhibited when the MCs were preincubated with the TcIP or with serum of T. crassiceps-infected NMRI mice from day 35 post infection and thereafter. In vitro degranulation of peritoneal MCs of infected mice was strongly inhibited beginning on day 10 after infection. Also in vivo degranulation of the IgE-sensitized rat skin MCs was significantly reduced by intradermal injection of the TcIP before (6, 3 and 1 h) antigen challenge and by preinjection (1 h) of serum from infected mice (day 80 p.i.)-The inhibitory effect was also demonstrated after immunoadsorption of mouse serum proteins naturally contaminating the TcIP. Heating (100 degrees C/15 min), even in the presence of 0.25 M HCl, did not suppress the inhibitory activity.

Animals↗
PubMed1974

Lymphocyte proliferation in vitro induced by hapten autologous protein conjugates. I. A study on the class of lymphocytes responding in vitro and on the nature and specificity of their receptors.

Immune lymph node cells from guinea pigs respond to soluble antigen in vitro by an increase in DNA synthesis. Optimal conditions for this proliferative response were studied in the present article. Under such conditions, immune cells showed increasing responses with increasing antigen concentration in vitro, the threshold dose of activation frequently being as low as 0.02 microg per culture. In contrast, normal lymph node cells (from FCA-stimulated animals) did only respond to antigen at very high doses (20 mg/culture), and immune cell dilution studies could be performed in normal cells without changing the kinetics of the antigen specific response of immune cells. Fractionation on anti-Ig columns indicated that purified, immune T lymphocytes were quite capable of proliferating in vitro upon antigen stimulation. However, our attempts to adsorb the proliferating cells onto chemically defined immunoadsorbants failed despite the fact that immune B cells (as measured by the rosette assay) were retained almost completely by such a procedure. Purified, immune T lymphocytes from guinea pigs immunized with different antigen concentrations in vivo and/or obtained at different times after immunization were tested for a differential sensitivity toward antigen-induced DNA synthesis in vitro. However, we were not able to demonstrate any regular increase in sensitivity to antigen in vitro, and if found, it seemed to be more dependent upon the number of antigen reactive cells in the population studied rather than upon differences in the average avidity of the receptors on the cells proliferating in vitro. The results in the present article are discussed in relation to current knowledge and hypotheses on T-lymphocyte receptors.

Animals↗
PubMed1975

Genetic control of the in vitro responses of rat blood lymphocytes. I. Comparison of in vitro and in vivo responses.

Nielsen, H. E. & Koch, C. Genetic Control of the In Vitro Responses of Rat Blood Lymphocytes. I. Comparison of In Vitro and In Vivo Responses, Scand. J. Immunol. 4, 31-36, 1975. In vitro DNA synthetic responses of blood lymphocytes from the inbred rat strains BN, Lewis, and AS were compared with each other after stimulation with allogeneic lymphocytes, human lymphocytes, phytohemagglutinin, and anti-Ig antibodies. BN lymphocytes responded less well than AS and Lewis lymphocytes regardless of the stimulus used. The responses of the congenic strains Lewis and Lewis. BN were identical, suggesting that H-1 (Ag-B)-linked loci do not determine in vitro responsiveness in these strains. In vivo, AS and BN rats were equally able to reject third-party skin grafts and to induce graft-versus-host reactions in F1 hybrids. We conclude that the interstrain differences found in vitro reflect genetically determined differences in in vitro kinetics, possibly related to the fraction of short-lived lymphocytes present rather than to demonstrable differences in the frequency of reactive lymphocytes.

Animals↗