The dose-effect problem in cytogenetic studies in vitro in chemotherapuetically treated probands

Primordial follicles are maintained in a quiescent state until they receive a signal to activate and join the growing pool. It is essential that the rate of follicle activation is well coordinated as it determines the reproductive lifespan of the female. This finely tuned process is under the control of a variety of positive and negative factors, and there is evidence that the JNK pathway is involved. The aim of this study was to assess the effect of a JNK inhibitor (SP600125) on follicle activation in vitro. Ovaries from 6 prepubertal sheep were dissected into 1-mm3 fragments and cultured in the presence or absence of SP600125 (0, 5, or 25 µM; SP0, SP5, and SP25, respectively). After 0, 2, 5, or 9 days, fragments were fixed, sectioned, and analysed by histological morphometry to determine the number and type of follicles in addition to TUNEL analysis for apoptosis. In total, 21 584 follicles were assessed. Follicles were classified as either primordial, intermediate, primary, secondary, or antral. Culture media were also assayed for steroid content. After multinomial regression analysis, there were no differences in the rate of follicle activation between groups on Day 2 of culture. However, after 5 days of culture there were significantly more primordial follicles in SP25 (69 ± 9.15%; P < 0.01) and SP5 (52 ± 8.12%; P < 0.05) groups when compared with SP0 (34 ± 3.98%). At the end of culture (Day 9), these differences continued to be observed (SP25: 63 ± 8.47%; SP5: 51 ± 6.62%; SP0: 34 ± 5.61%; P < 0.05). On Day 9 there were more intermediate follicles following treatment with SP0 (52 ± 3.27%) compared with SP5 and SP25 (42 ± 4.72% and 31 ± 7.41% respectively; P < 0.05). There was also a tendency for more primary follicles on Day 9 for the control (11 ± 4.29%) when compared with the other treatments (4 to 7%; P = 0.06). The proportion of apoptotic primordial follicles was greatest in the SP25 group when compared with SP5 and SP0 at all timepoints (P < 0.05). After 2 days of culture, progesterone concentration was highest in the SP25 group (4.1 ± 0.45 ng mL–1) compared with the SP5 and SP0 groups (2.9 ± 0.39 ng mL–1 and 1.6 ± 0.79 ng mL–1, respectively; P < 0.05). However, this dose effect was lost by the end of culture. There was no effect of the inhibitor on oestradiol synthesis. By using SP600125, we have observed a dose-dependent block on follicle activation. These results suggest that the JNK pathway is a novel regulator of follicle activation and development. However, further confirmation is required to determine its specific action. The mechanisms by which SP25 promotes progesterone synthesis and increases apoptosis are unknown and also require clarification.

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Exploiting Curcumin Synergy With Natural Products Using Quantitative Analysis of Dose–Effect Relationships in an Experimental In Vitro Model of Osteoarthritis

Frontiers in Pharmacology ◽

10.3389/fphar.2019.01347 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 3

Author(s):

Angela D’Ascola ◽

Natasha Irrera ◽

Roberta Ettari ◽

Alessandra Bitto ◽

Giovanni Pallio ◽

...

Keyword(s):

Natural Products ◽

Quantitative Analysis ◽

In Vitro Model ◽

Dose Effect ◽

Vitro Model

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Pharmacological Evaluation of Ticlopidine, A Novel Inhibitor of Platelet Function

10.1055/s-0039-1680487 ◽

1977 ◽

Author(s):

M. Johnson ◽

P. L. Walton ◽

R. C. Cotton ◽

C. J. L. Strachau

Keyword(s):

Survival Time ◽

Platelet Function ◽

Thrombus Formation ◽

Antiplatelet Agent ◽

Dose Effect ◽

Onset Of Action ◽

Duration Of Action ◽

Platelet Survival ◽

Induced Aggregation

Ticlopidine (T), 5-(2-chlorobenzyl)-4,5,6,7-tetrahydrothieno(3,2-C)pyridine hydrochloride (a product of Parcor Research) has been evaluated as an antiplatelet agent in various animal species and in human volunteers. T was inactive in vitro, but inhibited platelet aggregation induced by ADP, collagen, thrombin, arachidonic acid and prostaglandin (PG) endoperoxide, when administered orally to mice, rats, rabbits, guinea pigs, pigs, dogs and baboons. Platelet adhesiveness was reduced but platelet survival time was normal in treated animals. Basal PG synthesis and platelet ultra-structure were unaffected by T.T protected against acute thrombocytopenia and death from pulmonary embolism induced by i. v. injection of ADP or collagen. Thrombus formation in experimental models of extra-corporeal circulation and deep venous thrombosis was also impaired.In man, a single oral dose of 500mg was shown to be a potent inhibitor of ADP, collagen, adrenaline, ristocetin, bovine fibrinogen and 5HT-induced aggregation. A dose-effect relationship was apparent, 250 and 500mg resulting in ~47 and 75% inhibition of ADP-induced aggregation respectively. Inhibition was sustained by chronic daily dosing.There was a delay in the onset of action of T in vivo, but which then persisted after withdrawal for at least 48 hours, with no evidence of rebound hyperactivity. The duration of action of T correlated with platelet survival time, suggesting an irreversible modification of platelet function. T is a potent platelet inhibitor, exhibiting a novel mode of action and lack of agonist specificity, which may be of value in the treatment of thrombotic conditions.

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Immunologic and Cytogenetic Studies of Chronic Lymphocytic Leukemic Cells

Blood ◽

10.1182/blood.v26.2.121.121 ◽

1965 ◽

Vol 26 (2) ◽

pp. 121-132 ◽

Cited By ~ 90

Author(s):

JOOST J. OPPENHEIM ◽

JACQUELINE WHANG ◽

EMIL FREI

Keyword(s):

Tritiated Thymidine ◽

Lymphocyte Transformation ◽

Normal Subjects ◽

Peripheral Circulation ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Serum Factors ◽

Cytogenetic Studies

Abstract The lymphocyte transformation response of 17 chronic lymphocytic leukemia patients when tested in the short-term tissue culture with PHA-M, and PPD was found to be significantly decreased when compared to normal subjects. Serum factors were not found to be responsible for this cellular hyporesponsiveness. The proportions of immunoresponsive lymphocytes found in the patients’ peripheral circulation decreased as their white blood cell count increased. The transformation response to PHA-M was generally better than to PPD. Neither the PPD negative patients nor the normal PPD negative subjects’ cells responded to PPD stimulation in vitro. Monocytes usually would phagocytize particles added to the cultures and could thus be distinguished from the nonphagocytic proliferating lymphocytes which were the only cells that incorporated thymidine H3. Radioautographs of tritiated thymidine also revealed the rate of PPD lymphocyte transformation to be slower than with PHA-M. There were no significant differences in the proportions or the degree of leukemic and normal transformed lymphocyte labeling with tritiated thymidine. Cytogenetic studies revealed that the patients’ mitotic indices both in vivo and in vitro were markedly depressed. The modal chromosome number was 46 in each patient, and no cytogenetic abnormalities other than those due to exposure to radiation were found.

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