Proliferative phase

Hampson, E.C.G.M. and S.M. Pond. 1988. Ultrastructure of canine lung during the proliferative phase of paraquat toxicity. Brit. Jour. Exp. Pathol. 69 57-68... 

The most important activity of cyclosporin A consists clearly in the marked suppression of antibody formation and cell-mediated immune response [4, 5]. In addition, the metabolite exhibits antiphlogistic effects, restricted to chronic inflammation processes, as well as antifungal and antiparasitic activities. Whether these different biological activities are inter-related or represent separate mechanisms is still an open question. Considering immunosuppression, early observations revealed that cyclosporin A acts selectively on lymphocytes, mainly on T cells, affecting rather the inductive phase than the proliferative phase of lymphoid cell populations. Apparently, cyclosporin A inhibits primary T-helper cell activation and blocks the formation of... 

Estrogens increase the endothelium and rebuild the endometrial lining in the proliferative phase. 

Nissen NN, Polverini PJ, Koch AE, Volin MV, Gamelli RL, DiPietro LA. Vascular endothelial growth factor mediates angiogenic activity during the proliferative phase of wound healing. American Journal of Pathology 1998, 152, 1445-1452. 

Recently, Bernard et al. [499] studied oscillations in cyclical neutropenia, a rare disorder characterized by oscillatory production of blood cells. As above, they developed a physiologically realistic model including a second homeostatic control on the production of the committed stem cells that undergo apoptosis at their proliferative phase. By using the same approach, they found a local supercritical Hopf bifurcation and a saddle-node bifurcation of limit cycles as critical parameters (i.e., the amplification parameter) are varied. Numerical simulations are consistent with experimental data and they indicate that regulated apoptosis may be a powerful control mechanism for the production of blood cells. The loss of control over apoptosis can have significant negative effects on the dynamic properties of hemopoiesis. 

Q5 The endometrium contains a mixture of glands and blood vessels embedded in connective tissues after menstruation has finished it appears thin for a few days. Increasing levels of oestrogen from the follicle then stimulate the endometrium to thicken, the glands hypertrophy and blood vessels become more prominent. This is known as the proliferative phase. 

Inosine Monophosphate Dehydrogenase. Proliferative cells such as lymphocytes have high demands for the rapid supply of nucleotides to support DNA and RNA synthesis, as do viruses during their proliferative phase. The first dedicated step in the de novo biosynthesis of guanine nucleotides is conversion of inosinate to XMP, catalyzed by inosine monophosphate dehydrogenase (IMPDH). 

FUNCTION Necessary for development of secondary female characteristics. Needed for proliferation of the fiterine endometrium during the early (preovulatory, or proliferative) phase of the menstrual cycle. 

The first phase of the menstrual cycle in the uterus is the proliferative phase, which is followed by the secretory phase, and then by menstruation. Cyclic changes in hormonal levels control and orchestrate the events of the menstrual cycle. 

Liver regeneration takes place in three phases (7.) pre-replicative phase, with preparation for mitosis, (2.) proliferative phase, with wave-like mitoses at 6—8 hour intervals, and (3.) restitution phase, with reconstitution of the hver structure. There are two stages to this whole process (7.) priming, which is the transition of latent hepatocytes (Go) into the mitotic cycle (Gp — this reversible process is triggered by cytokines, hormones or other permissive substances, whereby the cells proliferate due to stimulation by the growth factor (2.) progression is the transition from Gi to DNA synthesis (S) — this transition point from Gi to S is marked by the expression of cyclin Di. 

Strawberry hemangiomas are congenital vascular lesions characterized by endothelial hyperplasia during the proliferative phase. The development and proliferation of capillary endothelium requires the presence of angiogenic factors, such as vascular endothelial growth factor. Epoetin has a proliferative effect on endothelial cells and can induce angiogenesis (104,105). 

The adverse effects of high-dose oxygen on the lungs take the form of an initial exudation of blood and fibrinous fluid into the alveoli followed by proliferation of fibroblasts and alveolar cells (2). The proliferative phase can be permanent (3). It is reflected in a reduced vital capacity and a reduced diffusion capacity (4) and appears to be proportional to the units of pulmonary toxic dose (UPTD) administered 1 UPTD is equivalent to 1 absolute atmosphere x 1 minute of exposure. If exposure exceeds 1000 UPTD it can be difficult to predict the outcome (5), owing to inter-patient differences in susceptibility. 

The process of wound healing after thermal injury (e.g. from laser treatment) involves re-epithelialization that starts within the first few hours after injury and continues throughout the different proliferative phases of skin repair. Viable keratinocytes (Figure 3.2) that are at the edge of the wound and have not suffered lethal or sublethal heat shock... 

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