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At least 469 records · Page 26Linked to original sources
PubMed2001

In vitro high frequency regeneration of plantlets of Vigna mungo and their ex vitro growth.

Of the five explants of V. mungo var. T9 used, the excised shoot tips gave best response with regard to offshoot formation followed by the embryonal axis explants. While a treatment comprising 0.5 mgL(-1) BAP, 0.5 mgL(-1) 2iP and 0.1 mgL(-1) NAA induced differentiation of an average 10 offshoots in shoot tip explants, only 3 offshoots were formed in the explants of embryonal axis in a treatment containing 0.5 mgL(-1) BAP and 0.1 mgL(-1) NAA, found optimum for them. Multiple shoots differentiated when explants with earlier regenerated and growing offshoots were first cultured in a treatment containing 0.1 mgL(-1) BAP, 0.25 mgL(-1) IAA and 5 mgL(-1) CCC and then subcultured in the same treatment but having only 1 mgL(-1) CCC. The isolated shoots rooted in 0.5 mgL(-1) IAA resulted in the formation of complete plantlets of an average height of 15 cm in 20 days. The in vitro-regenerated plants grew normally under field conditions and came to flowering as well.

Culture Media↗
PubMed1978

In vitro growth of cytotoxic human lymphocytes. I. Growth of cells sensitized in vitro to alloantigens.

Human lymphocytes sensitized to allogeneic determinants in vitro were continuously cultured on medium prepared from phytohemagglutinin-(PHA-P) stimulated human mixed lymphocyte cultures. With such human-conditioned medium (HCM), human peripheral lymphoid cells could be grown in culture for over 90 days with a doulbing time of about 54 hr. Cytotoxic lymphocytes could be grown in culture for this time with no loss of cytotoxicity or change in cytotoxic specificity.

Cells, Cultured↗
PubMed2005

Comparative analysis of direct and indirect implant impression techniques an in vitro study. An in vitro study.

Implant impression and transfer of the implant position to a working cast for rehabilitative purposes not always represent a predictable reconstructive step. The variable results depend on the transfer technique utilized and on the accuracy of the impression materials. The aim of this study was to compare the accuracy of the direct and indirect impression techniques and to analyze the distortion of different impression materials. An edentulous acrylic resin mandible was used as reference model: in the cuspid position 2 laboratory analogs were inserted perpendicularly to the occlusal plane and fastened with resin. Two impressions for each indirect and direct recording techniques with 4 different impression materials were made. Polyvinyl siloxanes were used for the repositioning implant level method. Polyethers were used for the ''pick up'' impression technique. Analysis of cast distortion was measured computing the inter-implant position on the developed models compared to that of the master model. Measurements were recorded by a digital caliper. The results of this in vitro study demonstrate that the direct impression technique is preferable to the indirect one and that the Impregum polyether impression material is the most precise when used in association with a direct technique.

Dental Impression Technique↗
PubMed1990

Detection of surgical pathogens by in vitro DNA amplification. Part I. Rapid identification of Candida albicans by in vitro amplification of a fungus-specific gene.

The management of candidemia and disseminated candidiasis depends on rapid, unambiguous identification of Candida. Such identification is retarded by the slow growth of Candida from clinical specimens. Administration of effective but potentially toxic antifungal therapy is often withheld pending identification. To circumvent this slow growth and thus to expedite diagnosis and therapy, the polymerase chain reaction (PCR) was used to amplify a segment of fungal DNA coding for the cytochrome P450L1A1 (lanosterol-14 alpha-demethylase) in vitro. The technique provides unambiguous evidence of C. albicans in as few as 6 hours with a detection threshold of 10 organisms in a 100 mu specimen. Clinical specimens of urine (n = 4), sputum (n = 6), wound fluid (n = 1, and blood (n = 2) were collected from patients, and C. albicans was conventionally documented at these sites; in each case, PCR was confirmed. Of 17 additional specimens that were culture negative, PCR suggested the presence of yeast in two of the specimens. PCR-based detection of surgical pathogens may have broad application in rapid screening for the presence of organisms either indigenous to a particular surgical intensive care unit or peculiar to selected patient populations.

Candida albicans↗
PubMed1977

In vitro induction of tumor-specific immunity. III. Lack of requirement for H-2 compatibility in lysis of tumor targets by T cells activated in vitro to oncofetal and plasmacytoma antigens.

Many recent studies have demonstrated that cytotoxic T lymphocytes (CL) activated to various antigens other than those of the H-2 complex, will lyse target cells only when H-2 compatibility exists between the CL and target cell. From these observations, it has been inferred that T lymphocytes might only be capable of responding to H-2 antigen or antigens that become associated with H-2 region gene products. Our results suggest that this is not the case, and that in some situations, cytotoxic T lymphocytes can specifically lyse target cells of different H-2 types. Two in vitro systems are described where primary induction of cytotoxic T lymphocytes to oncofetal and plasmacytoma antigens results in CL capable of lysing suitable targets bearing these antigens, of either syngeneic or allogeneic derivation. Thus it is proposed that although interaction antigens involving H-2 components may preferentially activate T lymphocytes, this does not imply a restriction on the recognition potential of T lymphocytes.

Animals↗
PubMed1978

Subpopulations of T and B lymphocytes in peripheral blood and lymphocytes reactivity to non-specific mitogens (PHA, Con A, PWM) in in vitro cultures in patients suffering from in vitro cultures in patients suffering from glomerulonephritis.

Studies were performed on 79 subjects, out of which 32 belonged to the control group and 47 suffered from glomerulonephritis. The number of T and B lymphocytes in peripheral blood was determined using the technique of E, EA and EAC-rosette tests. Also, the lymphocyte blast response to non-specific mitogens (PHA, Con A, PWM) was established in vitro. Patients suffering from acute proliferative glomerulonephritis, as compared to the control group, displayed a statistically significant increase of lymphocytes with the receptor for complement (EAC-rosettes). Their reactivity to all three mitogens did not differ from the values obtained in the control group. In patients suffering from chronic glomerulonephritis (proliferative, membranous-proliferative, membranous), shiftings in the contents of the peripheral blood lymphocytes pools were of opposite directions, i.e., statistically significant in comparison with the control group. Also an increase in the absolute number of T lymphocytes (E-rosettes) was observed. Generally speaking, the values of blast transformations after mitogen stimulations were smaller in patients suffering from chronic than in those suffering from acute glomerulonephritis. In 1/3 of them, the decrease of blast response to one of the three mitogens was detected. The decrease exceeded the lower limit of values of healthy subjects, and most often, it was connected with Con A stimulation.

B-Lymphocytes↗
PubMed1988

[In vitro combination effects of astromicin and beta-lactam antibiotics against CFS-sensitive and CFS-resistant Pseudomonas aeruginosa. In vitro synergistic activity].

We investigated in vitro synergistic activity of astromicin (ASTM) combined with beta-lactam antibiotics (cefsulodin (CFS), cefoperazone (CPZ), ceftazidime (CAZ), piperacillin (PIPC) and fosfomycin (FOM) against fresh clinical isolated Pseudomonas aeruginosa, which consisted of 13 CFS sensitive (MIC less than or equal to 3.13 micrograms/ml) and 19 CFS resistant (MIC greater than or equal to 400 micrograms/ml) strains according to the FIC index. Against CFS-sensitive P. aeruginosa, ASTM showed good synergistic activities when combined with PIPC (54%), CAZ (38%), CPZ (23%) and CFS (8%). Against CFS-resistant P. aeruginosa, ASTM also showed high synergistic activities when combined with CAZ (63%), CPZ (47%), PIPC (37%) and CFS (11%). Among the CFS-resistant P. aeruginosa, one clinical isolate showed a high sensitivity (MIC0.78 micrograms/ml) against ASTM alone.

Aminoglycosides↗
PubMed1985

[In vitro combination effects of astromicin and beta-lactam antibiotics against Pseudomonas aeruginosa. In vitro synergistic activities].

In vitro synergistic activities of astromicin (ASTM), a new aminoglycoside antibiotic, combined with beta-lactam antibiotics (cefsulodin (CFS), cefoperazone (CPZ), latamoxef (LMOX) were investigated against P. aeruginosa by the checkerboard technique, FIC index and the killing curve. FIC indexes of ASTM in combination with beta-lactam antibiotics against 11 fresh clinical isolates of P. aeruginosa, P. aeruginosa BMH No. 1 and E-2 were synergistic or partially synergistic in most cases. Checkerboard of P. aeruginosa BMH No. 1 and E-2 to ASTM and 3 beta-lactam antibiotics showed the synergism, too. Bacteriostatic concentrations of ASTM, CFS, CPZ or LMOX showed synergistically bactericidal effects when these antibiotics were added in combination to the culture of P. aeruginosa BMH No. 1.

Aminoglycosides↗
PubMed1979

[Autoradiographic investigations on the effect of city smog extract on DNA synthesis and cell cycle of mammalian cells in vitro. I. Effect of city smog extract on DNA synthesis of kidney- and embryonic cells of the golden hamster in vitro (author's transl)].

We analysed the effect of city smog extract from Düsseldorf on DNA synthesis of mammalian cells in vitro. Airborne dust was extracted with aceton and thereafter transferred to dimethylsulfoxide. Dosage was calculated according to the benzo(a)pyrene content. We used logarithmically growing cultures of hamster kidney and embryonic cells. DNA synthesis was determined autoradiographically by incorporation of 3H-Thymidine. We found that city smog extract exerted a dose-dependent cytotoxic effect leading to a decrease of DNA synthesizing cells. High concentrations of city smog extract induced cell necrosis and suppressed DNA synthesis completely. Moderate doses of extract caused a dose-dependent, but temporary cessation of DNA synthesis. Cells resumed DNA synthesis after a certain delay. Low concentrations of city smog extract induced no detectable effects. Inhibition of DNA synthesis was evident already one hour after addition of extract. Therefore a direct effect on DNA metabolism could be supposed. Furthermore, exposed cultures demonstrated a delay in entrance of new cells into the DNA synthesis. Alterations in DNA synthesis could be of great importance for carcinogenesis, especially if we take in consideration the content of carcinogens in city smog extract.

Animals↗
PubMed1982

[Fatal granulocyte function defect in a male infant. Results of in vitro and in vivo stimulation with ascorbic acid as well as in vitro stimulation with levamisol and lithium chloride].

We report about a boy who suffered from repeated bacterial infections starting at the age of 4 weeks. A severe defect of chemotactic activity of the neutrophils, and an additional deficient phagocytosis were discovered. The child died at the age of 3 months from septicemia. Chemotactic activity could be stimulated in vitro by ascorbic acid and levamisole but not by lithium chloride. In vivo, however, the effect of ascorbic acid was minimal and treatment with this vitamin could not prevent the lethal end.

Ascorbic Acid↗
PubMed1984

[Sensitivity of Plasmodium falciparum to chloroquine in the hyperendemic malaria savannah zone of Burkina Faso ex-Upper Volta. Use of in vivo and in vitro tests. Demonstration of a resistant strain in vitro].

Studies on the response of P. falciparum to chloroquine was conducted in schools located in the environs of Koudougou (Burkina Faso, Upper-Volta), where malaria is meso to hyperendemic, using in vivo studies and in vitro macroculture tests. Cases were obtained from school children, semi-immune asymptomatic carriers, in the 7-12 years-group.

Burkina Faso↗
PubMed1983

[Culture of mouse embryo for the toxicological evaluation of drugs in vitro. (1). Establishment of in vitro culture system and effect of 6-mercaptopurine on development of early stage embryo].

The basal conditions for culture of early mouse embryo in vitro were examined for drug evaluation. Among the media tested, BMOC-III was most suitable for mouse embryo culture. Changing the medium at 1 or 3 hr after culture was harmful to the survival and/or development of early staged embryos, whereas at 12 or 24 hr after culture, changing of the medium showed slight effect on embryo development. Eight-cell staged embryos were more resistant to changing medium that two-cell staged ones. Preliminary work using a suitable culture system established that exposure to 6-mercaptopurine for 12 or 24 hr resulted in a prolonged developmental rate at each stage. The effects showed a dose-dependent relationship with the 24 hr exposure. It was suggested that inhibition of the developmental rate during exposure resulted from a direct toxic effect on the cell and that the inhibition after exposure resulted from metabolic toxicity.

Animals↗
PubMed1981

[In vitro study of comparative immunosuppressive activity of sera from pregnant women on an in vitro cellular cytotoxic reaction].

By means of an adaptation of a well-known in vitro cellular cytotoxic reaction we can demonstrate: 1. a strong immunosuppressive non-specific activity of sera from pregnant women; 2. a decrease or an absence of immunosuppressive activity of sera from pregnant women submitted to several spontaneous abortions; 3. we propose a reliable and simple test allowing us to predict the outcome of abortions.

Abortion, Spontaneous↗
PubMed1998

[Revalidation of the in vitro specification limits after an in vitro-in vivo correlation].

A "Level A" in vitro/in vivo correlation was established for a sustained release theophylline (CAS 58-55-9) preparation (Bronchoretard) under investigation. Such a functional relationship is a valuable tool for predicting the in vivo performance of a product. Additionally, the in vitro specification limits could be justified or even enlarged based on such an extrapolation.

Anti-Asthmatic Agents↗
PubMed1998

In vitro expansion of CD34+/CD41+ cells from human peripheral blood CD34+/CD41- cells: role of cytokines for in vitro proliferation and differentiation of megakaryocytic progenitors.

The aim of this study is to clarify the transitional change of the proliferation and differentiation of human peripheral blood CD34+ cells to megakaryocytic lineage, focusing on its clinical application. We developed a rapid system to purify human peripheral blood CD34+ cells from healthy volunteers, which produced CD34+ cells with a 90% purity. The purified CD34+ cells predominantly consisted of CD41- cells, and the rate of coexpression of CD41 was 0.6% +/- 0.5%. When the purified cells were cultured in liquid phase for 10 days in the presence of recombinant human stem cell factor (rSCF: a ligand for c-kit), interleukin-3 (rIL-3), and thrombopoietin (rTPO: a ligand for Mpl), the number of CD34+/CD41+ cells increased to 19% +/- 7% of total expanded cells on day 4 (4 days of liquid culture) and then gradually decreased to 2.2% +/- 0.6% on day 10. The absolute number of CD34+/CD41+ cells increased and reached a plateau on day 6, and 1.7 +/- 0.6 x 10(5) CD34+/CD41+ cells were produced by 1 x 10(5) CD34+/CD41- day 0 cells. The CD34-/CD41+ cells appeared on day 6, continuously increased in number until day 10, and constituted the main population of expanded cells on day 10, with a value of 38% +/- 18%. On day 10, 19.5 +/- 10.6 x 10(5) of CD34-/CD41+ cells were produced by 1 x 10(5) CD34+/CD41- day 0 cells. The deletion of rTPO from this cytokine combination decreased the number of CD34+/CD41+ and CD34-/CD41+ cells, after days 6 and 8, respectively. Day 0 cells required rIL-3 for promoting colonies containing megakaryocytes, whereas rTPO alone promoted almost no megakaryocytic colonies from day 0 cells. Thus, a combination of IL-3 and SCF expands CD34+/CD41+ cells from CD34+/CD41- cells, and TPO mainly acts to increase CD34-/CD41+ cells. This study suggests that if the expansion of CD34+/CD41+ is performed in vitro, the 6 days' culture of peripheral blood CD34+/CD41- cells with a combination of IL-3 and SCF with TPO provides the most rapid and stable products of CD34+/CD41+ cells for the rapid recovery of platelets in patients with peripheral blood stem cell transplantation.

Adult↗
PubMed1997

Antiproliferative activity in vitro and in vivo of the spicamycin analogue KRN5500 with altered glycoprotein expression in vitro.

The spicamycin analogue KRN5500 (NSC 650426; SPA) is derived from Streptomyces alanosinicus. The unique structure contains a purine, an aminoheptose sugar, glycine, and a tetradecadiene fatty acid. SPA potently inhibits the growth of certain human tumor cell lines in vitro (IC50 for growth <100 nM) and displays marked activity in vivo in Colo 205 colon carcinoma xenografts. Selective inhibition of labeled precursor incorporation was not evident at 1 or 4 h of exposure to the drug, but at 8 h, [3H] leucine incorporation was inhibited by approximately 40% at or below the IC50 for cell growth. Because of the structural similarity of SPA to inhibitors of glycoprotein processing, we examined the effect of SPA on indicators of glycoprotein synthesis and processing in HL60TB promyelocytic leukemia and Colo 205 colon carcinoma cells. Brief periods of exposure ( approximately 30 min) to SPA at the IC50 for growth increased incorporation of [3H]mannose. When examined by Western blotting after prolonged (40-48 h) incubation with lectins that target mannose-containing carbohydrates, Galanthus nivalis agglutinin and concanavalin A, a qualitative change in the pattern of mannose-containing glycoproteins was observed in HL60TB cells. Significant changes in the pattern of surface glycoprotein expression in intact cells were demonstrated by flow cytometry using fluorescence-labeled lectins. An increase in the number of cells binding G. nivalis agglutinin (indicating terminal mannose) was noted, but a decrease in the amount of lectin bound per cell was noted for wheat germ agglutinin (detecting sialic acid and terminal beta-N-acetyl glucosamine residues). Electron microscopy revealed loss of microvilli, and the Golgi apparatus appeared inflated. Our findings, therefore, raise the possibility that cells exposed to SPA have altered glycoprotein processing after exposure to low concentrations of drug, prior to the occurrence of overt cytotoxicity. These effects are consistent with a prominent early effect of SPA on the enzymatic machinery or organelles important for proper glycoprotein processing and emphasize the novelty of this agent's likely mechanism of action.

Animals↗