We examined the plasma nerve growth factor (NGF) level and the distribution of NGF receptors in peripheral lymphocytes of young soldiers (mean age, 20-24 yr) experiencing the thrill of a novice about to make their first parachute jumps. Blood was collected from soldiers who knew they were selected to jump (n = 26), as well as from soldiers who knew they were not selected (n = 17, controls). The former group was sampled the evening before the jump and 20 min after landing. Compared with controls, NGF levels increased 84% in prejump and 107% in postjump sampling. Our studies also showed that the increase of NGF levels preceded the increase of plasma cortisol and adrenocorticotropic hormone. No changes in the baseline levels of circulating interleukin 1 beta or tumor necrosis factor were found, suggesting that the increased levels of NGF were not correlated with change in these cytokines. Moreover, immunofluorescence analysis demonstrated that parachuting stress enhances the distribution of low-affinity p75LNGFR and high-affinity p140trkA NGF receptors in circulating peripheral blood mononuclear cells. These observations suggest that the release of NGF might be involved in the activation of cells of the immune system and is most probably associated with homeostatic adaptive mechanisms, as previously shown for stressed rodents.

Nerve growth factor (NGF) is a polypeptide which, in addition to its effect on nerve cells, is believed to play a role in inflammatory responses and in tissue repair. Because fibroblasts represent the main target and effector cells in these processes, to investigate whether NGF is involved in lung and skin tissue repair, we studied the effect of NGF on fibroblast migration, proliferation, collagen metabolism, modulation into myofibroblasts, and contraction of collagen gel. Both skin and lung fibroblasts were found to produce NGF and to express tyrosine kinase receptor (trkA) under basal conditions, whereas the low-affinity p75 receptor was expressed only after prolonged NGF exposure. NGF significantly induced skin and lung fibroblast migration in anin vitromodel of wounded fibroblast and skin migration in Boyden chambers. Nevertheless NGF did not influence either skin or lung fibroblast proliferation, collagen production, or metalloproteinase production or activation. In contrast, culture of both lung and skin fibroblasts with NGF modulated their phenotype into myofibroblasts. Moreover, addition of NGF to both fibroblast types embedded in collagen gel increased their contraction. Fibrotic human lung or skin tissues displayed immunoreactivity for NGF, trkA, and p75. These data show a direct pro-fibrogenic effect of NGF on skin and lung fibroblasts and therefore indicate a role for NGF in tissue repair and fibrosis.

The ocular surface is extensively supplied by sensory and autonomic nerve fibers that play a crucial role in maintaining healthy epithelia and represent the main sources of neurogenic inflammation.^1-3 Cross-communication between the nervous and immune systems is shown by the release and binding of common neuromediators and cytokines.^4-6 Specifically, substance P (SP), calcitonin gene–related peptide (CGRP), vasoactive intestinal peptide (VIP), and neuropeptide Y (NPY) are released from ocular surface epithelial cells, lacrimal gland tissues, and nerve endings at inflammatory sites, modulating the infiltration and activation of the immune cells and triggering the reflex of tearing and ocular discomfort.^7,8

Cytarabine is a pyrimidine nucleoside analog, commonly used in multiagent chemotherapy regimens for the treatment of leukemia and lymphoma, as well as for neoplastic meningitis. Ara-C-based chemotherapy regimens can induce a suboptimal clinical outcome in a fraction of patients. Several studies suggest that the individual variability in clinical response to Leukemia & Lymphoma treatments among patients, underlying either Ara-C mechanism resistance or toxicity, appears to be associated with the intracellular accumulation and retention of Ara-CTP due to genetic variants related to metabolic enzymes. Herein, we reported (a) the latest Pharmacogenomics biomarkers associated with the response to cytarabine and (b) the new drug formulations with optimized pharmacokinetics. The purpose of this review is to provide readers with detailed and comprehensive information on the effects of Ara-C-based therapies, from biological to clinical practice, maintaining high the interest of both researcher and clinical hematologist. This review could help clinicians in predicting the response to cytarabine-based treatments.

Nerve growth factor (NGF) is a neurotrophin with the ability to exert specific effects on cells of the immune system. Human monocytes/macrophages (M/M) infected in vitro with HIV type 1 (HIV-1) are able to produce substantial levels of NGF that are associated with enhanced expression of the high-affinity NGF receptor (p140 trkA) on the M/M surface. Treatment of HIV-infected human M/M with anti-NGF Ab blocking the biological activity of NGF leads to a marked decrease of the expression of p140 trkA high-affinity receptor, a concomitant increased expression of p75 ^NTR low-affinity receptor for NGF, and the occurrence of apoptotic death of M/M. Taken together, these findings suggest a role for NGF as an autocrine survival factor that rescues human M/M from the cytopathic effect caused by HIV infection.