In Vitro Screening of Cytotoxic Substances Using Different Tumour Cells

Azalea lace bug (Stephanitis pyrioides) is the most serious pest on azalea. Results of laboratory bioassays and field evaluations of 17 deciduous azalea taxa have identified three resistant taxa: R. canescens, R. periclymenoides, and R. prunifolium. Highly susceptible taxa are `Buttercup', `My Mary', R. oblongifolium, and the evergreen cultivar `Delaware Valley White'. To determine whether in vitro techniques would have potential value in screening or selecting for resistance, or for the identification of morphological or chemical factors related to resistance, an in-vitro screening assay was developed. In-vitro shoot proliferation was obtained using the medium and procedures of Economou and Read (1984). Shoots used in the bioassays were grown in culture tubes. Two assays were developed: one for nymphs and one for adult lace bugs. To assay for resistance to nymphs, `Delaware Valley White' leaves containing lace bug eggs were disinfested with 70% alcohol and 20% commercial bleach, and incubated in sterile petri plates with moistened filter paper until the nymphs hatched. Five nymphs were placed in each culture tube, and cultures were incubated for about 2 weeks, or until adults were observed. To assay for resistance to adults, five female lace bugs were placed in each culture tube and allowed to feed for 5 days. Data collected on survival and leaf damage was generally supportive of laboratory bioassays and field results. Adult lace bugs had a low rate of survival on resistant taxa. Survival of nymphs was somewhat reduced on resistant taxa.

Download Full-text

In Vitro Screening of Some Heterocyclic Compounds Against Human ABHD6 and ABHD12 Hydrolases

Letters in Drug Design & Discovery ◽

10.2174/1570180811666140313233940 ◽

2014 ◽

Vol 11 (7) ◽

pp. 944-952 ◽

Cited By ~ 1

Author(s):

Agnieszka Kaczor ◽

Antti Poso ◽

Monika Pitucha

Keyword(s):

Heterocyclic Compounds ◽

In Vitro Screening

Download Full-text

PLATELET ACTIVATION BY HUMAN CANCER CELLS GROWN “IN VITRO” OR DISSOCIATED FROM TUMOUR TISSUES

10.1055/s-0038-1643200 ◽

1987 ◽

Author(s):

G Grignani ◽

L Pacchiarini ◽

M Zucchella ◽

L Dezza ◽

S C Rizzo

Keyword(s):

Platelet Aggregation ◽

Platelet Activation ◽

Human Cancer ◽

Iodoacetic Acid ◽

Tumour Cells ◽

Human Cancer Cells ◽

Human Tumour Cells ◽

Dissociated Cells ◽

Lymphoblastic Cells

The mechanisms of platelet activation by human tumour cells grown “in vitro” or freshly dissociated from tumour tissues have been investigated.MoCCL human T-lymphoblastic cells cultured “in vitro” induced platelet aggregation through the production of ADP, as evidenced by inhibition of the effect by apyrase. The maximum of ADP production by tumour cells was reached after 1 hour and was 225 p moles/106 cells.On the contrary, platelet aggregation induced by 5637 human bladder carcinoma cells was not inhibited by apyrase, but was abolished by hirudin, indicating the important role of thrombin in this effect.Tumour cells dissociated from 3 breast carcinomas showed a very high platelet aggregating activity, which was not inhibited by hirudin or apyrase, but was abolished by iodoacetic acid, suggesting a role for a cystein-protease in platelet activation.These results confirm that platelets can be activated by tumour cells through different mechanisms; they also suggest that the methods employed to obtain the tumour cells can influence the results, probably because of the different cell populations which are present in the dissociated tumour tissues.Informations obtained with freshly dissociated cells are interesting, because this method has been used seldom so far and because it provides a more physiological approach to the study of the interactions of tumours and platelets.

Download Full-text

Prolactin secretion and dopamine receptors of the MtTW15 transplantable pituitary tumour

Journal of Endocrinology ◽

10.1677/joe.0.0940347 ◽

1982 ◽

Vol 94 (3) ◽

pp. 347-NP ◽

Cited By ~ 13

Author(s):

M. J. Cronin ◽

D. A. Keefer ◽

C. A. Valdenegro ◽

L. G. Dabney ◽

R. M. MacLeod

Keyword(s):

Pituitary Gland ◽

Dopamine Receptors ◽

Anterior Pituitary ◽

Pituitary Tumour ◽

Prolactin Secretion ◽

Tumour Cells ◽

Dopamine Antagonist ◽

Cell Column ◽

Prolactin Release

The MtTW15 transplantable pituitary tumour grown in rats was tested in vitro for the ability of dopamine agonists to affect prolactin secretion and for the existence of dopamine receptors. Prolactin release from enzymatically dispersed cells and non-enzymatically treated tissue fragments of both the tumour and the anterior pituitary gland was determined in a cell perifusion column apparatus. Dopamine (0·1–5 μmol/l), bromocriptine (50 nmol/l) and the dopamine antagonist haloperidol (100 nmol/l) had no effect on prolactin release from the tumour cells. In contrast, dopamine (500 nmol/l) inhibited prolactin secretion from normal anterior pituitary cells in a parallel cell column and haloperidol blocked this inhibition. Although oestrogen treatment in vivo stimulated prolactin release in vitro when the tumour was removed and studied in the cell column, oestrogen had no effect on the inability of dopamine to modify the prolactin secretion. Growth hormone release from the tumour cells was not affected by dopamine. Although MtTW15 cells were refractory to dopaminergic inhibition of prolactin release, the dopamine receptors present in tumour homogenates were indistinguishable from the dopamine receptors previously defined in the normal anterior pituitary gland. The binding of the dopamine antagonist [3H]spiperone to the tumour was saturable (110 fmol/mg protein), of high affinity to one apparent class of sites (dissociation constant = 0·12 nmol/l), reversible and sensitive to guanine nucleotides. The pharmacology of the binding was defined in competition studies with a large number of agonists and antagonists. From the order of potency of these agents, a dopaminergic interaction was apparent. We conclude that the prolactin-secreting MtTW15 tumour cells appear to be completely unresponsive to dopamine or to the potent dopamine agonist bromocriptine, in spite of apparently normal dopamine receptors in the tumour.

Download Full-text

Thiosemicarbazole (Thiacetazone-Like) Compound with Activity against Mycobacterium avium in Mice

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.47.8.2685-2687.2003 ◽

2003 ◽

Vol 47 (8) ◽

pp. 2685-2687 ◽

Cited By ~ 27

Author(s):

Luiz E. Bermudez ◽

Robert Reynolds ◽

Peter Kolonoski ◽

Pricilla Aralar ◽

Clark B. Inderlied ◽

...

Keyword(s):

Mycobacterium Avium ◽

Significant Activity ◽

In Vitro Screening ◽

Single Drug ◽

Drug Regimens

ABSTRACT In vitro screening of thiacetazone derivatives indicated that two derivatives, SRI-286 and SRI-224, inhibited a panel of 25 Mycobacterium avium complex (MAC) isolates at concentrations of 2 μg/ml or lower. In mice, SRI-224 and thiacetazone had no significant activity against the MAC in livers and spleens, but treatment with SRI-286 resulted in significant reduction of bacterial loads in livers and spleens. A combination of SRI-286 and moxifloxacin was significantly more active than single drug regimens in liver and spleen.

Download Full-text