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L Aloe

Publications and source records attributed to L Aloe.

At least 37 records · Page 2Linked to original sources
PubMed2002

Improving ischaemic skin revascularisation by nerve growth factor in a child with crush syndrome.

Nerve growth factor (NGF) is the first described neurotrophin that stimulates the growth and differentiation of nerve cells and promotes skin and peripheral tissue regeneration. Recent studies suggest that NGF influences endothelial cell proliferation and angiogenic activity. In view of these proposed regenerative effects, we evaluated the efficacy of subcutaneous administration of highly purified murine NGF in a child with severe crush syndrome of the lower left limb. NGF 10 micro g was administered subcutaneously every eight hours for seven days to the extensive ischaemic skin lesion of the calcaneal area. After treatment we observed gradual improvement of the ischaemic area; no side effects were noted. The child was discharged in good clinical condition to await a limited calcaneal escharotomy.

Child, Preschool↗
PubMed2002

Cholecystokinin-8 and nerve growth factor: two endogenous molecules working for the upkeep and repair of the nervous system.

Cholecystokinin-8 (CCK-8), the small peptide initially described as a gastric factor involved in the regulation of feeding behavior, is today recognized as one of the most abundant neurotransmitters/ neuropeptides in brain and is an important signal factor for the peripheral and central nervous systems. In the past twenty years, many studies have focused on possible clinical applications of this peptide and its receptor ligands in psychiatric diseases and gastrointestinal pathologies. Recently it has been suggested that CCK-8 may also have a neuroprotective role, thus opening a new field of interest around the physiology and the pharmacology of this neuropeptide and its receptors. It has been demonstrated that CCK-8 counteracts neuronal deficit following chemical or surgical lesions in both the central and peripheral nervous systems and that Nerve Growth factor (NGF) is involved in the CCK-induced recovery process. By using selective CCK receptor antagonists it has been demonstrated that CCK-8, when injected intraperitoneally, has the ability to stimulate NGF synthesis in brain and peripheral organs by a mechanism that involves the activation of CCK receptors. As has been widely reported, NGF is an essential survival and differentiative factor for selective neuronal populations of the PNS and CNS and plays a role in the events of degeneration and repair of the nervous system in diseases with different etiologies, e.g. neurodegenerative and autoimmune diseases as well as diabetes-associated pathologies. The possibility of using NGF in therapy has been evaluated and systemic and intracerebral NGF treatment have been tested in patients and animal models. Although the results of these studies are encouraging, the difficulty to predict and/or eliminate the side effects of NGF/NGF antibody treatment has made it difficult to fully evaluate the potential of the beneficial effects. In this context recent results obtained in our laboratories may offer a new prospective for the pharmacological approaches to the diseases associated with altered NGF production and functions. The data of our recent observations on NGF and CCK-8 is covered in this review.

Animals↗
PubMed2002

Developmental expression of nerve growth factor in the eye of rats affected by inherited retinopathy: correlative aspects with retinal structural degeneration.

We have previously reported that exogenous administration of nerve growth factor (NGF) in C3H/HeJ mouse strain affected by retinitis pigmentosa (RP) delayed retinal degeneration, suggesting that NGF may be implicated in retinal development. Whether NGF is present in the developing eye was not investigated. To address this question we have used Royal College of Surgeons (RCS) rats, characterised by photoreceptor loss during postnatal life. The results of these studies showed that while the thickness of the outer nuclear layer (ONL) of RCS is comparable to controls, while the amount of NGF expressed in the eye of this mutant rat is significant lower, as compared to control eye. This observation suggests that the lower presence of NGF in the eye of RCS rats during early postnatal life might be one critical key factor implicated in RP. The results of these studies will be presented and discussed.

Aging↗
PubMed2001

Bromodeoxyuridine and methylazoxymethanol exposure during brain development affects behavior in rats: consideration for a role of nerve growth factor and brain derived neurotrophic factor.

Rats prenatally exposed to the neurotoxins methylazoxymethanol (MAM) or 5-Bromo-2'-deoxyuridine (BrdU) are used as animal models of brain maldevelopment. We administered in rats MAM (20 mg/kg), or BrdU (100 mg/kg) or both at gestational day 11. Locomotion was not affected by any prenatal treatment whereas learning was delayed in the Morris maze in MAM animals. BrdU induced decreased NGF and BDNF levels in the hippocampus. In the parietal cortex prenatal BrdU administration induced NGF potentation associated with decreased BDNF. Animals treated with both MAM and BrdU showed also an increased immunopositivity for choline acetyltransferase (ChAT) and low affinity neurotrophins' receptor (p75) in the septum and Meynert's nuclei. These findings suggest that embryonic exposure to MAM and/or BrdU may be useful for studying mechanisms associated with neurodegenerative diseases affecting brain morphology and behavior.

Animals↗
PubMed2001

The upregulation of nerve growth factor receptors in reactive astrocytes of rat spinal cord during experimental autoimmune encephalomyelitis.

Using immunocytochemistry, we have examined the effect of experimental autoimmune encephalomyelitis (EAE) upon the expression of nerve growth factor (NGF) and its TrkA and p75 receptors in astroglia cells of the spinal cord of Lewis rats. We have found that, in normal spinal cord, astroglia of white matter expressed both NGF receptors while those in gray matter expressed only TrkA and no astroglia expressed NGF. During EAE, strong upregulation of TrkA in the astroglia of gray and white matter was found, particularly in a population of radially oriented astrocytes. An upregulation of p75 was noted in radial astroglia and, to some extent, also in the stellate astrocytes of white matter. In general, the upregulation of NGF receptor immunoreactivities in astroglia correlated with the strong intensification of glial fibrillary acidic protein immunocytochemistry, a prominent feature of EAE. No NGF immunoreactivity appeared in any astroglia cells during EAE. Our results suggest that, during EAE, astroglia of the spinal cord become particularly receptive to NGF, possibly as part of a mechanism enabling astroglial cells to respond to localized release of neurotrophins. Moreover, our data suggest that spinal cord astroglia cells may be a potential target for pharmacological manipulations in EAE.

Animals↗
PubMed2001

Cholecystokinin-8 promotes recovery of sympathectomy induced by 6-hydroxydopamine in adult mice.

We used an experimental model of sympathetic neuropathy to investigate the effects of intraperitoneal cholecystokinin-8 (CCK-8) administration on the recovery of injured peripheral neurones. After treatment of adult mice with 6-hydroxydopamine (6-OHDA), which known to induce peripheral sympathectomy, nerve growth factor (NGF) in peripheral tissue first increased and then rapidly decreased to baseline levels. Following this observation, sympathectomised mice were treated with CCK-8 starting when the NGF levels lowered toward the control value. Our results show that injections with 8 nmol/kg of CCK-8 promote not only recovery of noradrenergic innervation but also NGF and neuropeptide Y (NPY) synthesis in peripheral tissue. This latter observation suggests that the effect of CCK-8 might be mediated through the stimulation of NGF synthesis.

Animals↗
PubMed2001

Nerve growth factor displays stimulatory effects on human skin and lung fibroblasts, demonstrating a direct role for this factor in tissue repair.

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 an in vitro model 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.

Actins↗
PubMed2001

Effect of hypergravity on the mouse basal expression of NGF and BDNF in the retina, visual cortex and geniculate nucleus: correlative aspects with NPY immunoreactivity.

We investigated the effect of hypergravitation on Nerve growth factor (NGF) and Brain-derived-neurotrophic factor (BDNF) expression in the visual cortex, geniculate nucleus (GN), and retina of adult male mice. The results showed that altered gravity causes an increase in NGF and BDNF in the visual cortex and GN which resulted to be associated with an up-regulation of cells immunoreactive to neuropeptide Y (NPY) in the visual cortex and GN. We also found a decrease in NGF, BDNF, and NPY in the mouse retina exposed to hypergravity. These findings suggest that alteration in gravitational environment differentially affects local neurotrophic factors and NPY expression. The possible functional significance of these observations is discussed.

Animals↗
PubMed2001

Nerve growth factor control of neuronal expression of angiogenetic and vasoactive factors.

In postnatal tissues, angiogenesis occurs in nontumoral conditions on appropriate stimuli. In the nervous tissue, hypoxia, neural graft, increased neural function, and synaptic activity are associated with neoangiogenesis. We have investigated the occurrence of neoangiogenesis in the superior cervical ganglia (scg) of newborn rats treated for 8--21 days with 6-hydroxy-dopamine (6-OHDA), nerve growth factor (NGF), or 6-OHDA + NGF. The two latter treatments induced a significant increase in scg size. However, the increase after combined treatment far exceeded that of NGF alone. Similarly, histological and histochemical analysis revealed neuronal hypertrophy and endothelial cell hyperplasia associated with stromal hypertrophy (as described by laminin immunostaining) and increased vascular bed (as revealed by platelet/endothelial cell adhesion molecule-1 immunostaining) in 6-OHDA + NGF-treated pups. NGF, either alone or associated with 6-OHDA, also induced a significant up-regulation of NADPH diaphorase, neuronal nitric oxide synthase, and vascular endothelial growth factor expression in scg neurons. The present investigation suggests that the increase of scg size induced by NGF and 6-OHDA + NGF is associated with neoangiogenesis, and that the induction of vasoactive and angiogenic factors in neurons represents a further and previously undisclosed effect of NGF.

Adrenergic Agents↗
PubMed2001

Human monocyte/macrophages activate by exposure to LPS overexpress NGF and NGF receptors.

Monocyte/macrophages (M/M) represent the main cellular component of the immune system involved in the inflammatory response. In the present study we investigate whether NGF is produced by M/M and is involved in this event. The results show that unstimulated human M/M produce NGF and its synthesis is stimulated by LPS. The increase of NGF is associated with enhanced expression of high affinity NGF receptor on M/M and with no changes of low affinity NGF receptors (p75). The neutralization of endogenous NGF by NGF antibody in LPS-activated M/M, leads to overexpression of p75 receptor causing apoptosis. These findings provide new insight in the mechanisms governing monocyte survival in the inflamed tissue, representing a crucial aspect of host defence and maintenance of homeostasis.

Adult↗
PubMed2001

Nerve growth factor levels and mast cell distribution in human coronary atherosclerosis.

Nerve growth factor (NGF), in addition to its neurotrophic function, acts on a variety of non-neuronal cells including immune cells and vascular smooth muscle cells. The aim of the present study was to determine the NGF levels and the distribution of NGF and low-affinity NGF receptor (p75NGFR) and mast cells (MC) in human atherosclerotic coronary arteries. Specimens of human coronary arteries obtained from autopsy cases (n=12, subjects with atherosclerotic lesions; n=9, subjects without atherosclerotic lesions/controls) were used. The present study showed that in the atherosclerosis-lesioned arteries, the amount of NGF decreased, whereas the expression of p75NGFR immunoreactivity and the number, both of MC and vasa vasorum, particularly in the adventitia, significantly increased, compared with the control arteries. Cumulatively, our findings help to set the neurotrophic theory and its currently extended neuroimmune framework into the context of pathobiology of atherosclerosis, suggesting that altered presence of NGF, p75NGFR, and MC may play a role in neuroimmune mechanisms of human coronary atherosclerosis.

Adult↗
PubMed2001

Nerve growth factor and neuroimmune responses: basic and clinical observations.

Nerve growth factor (NGF) is a polypeptide that in addition to its effect on survival of peripheral and brain neuron acts also on a variety of cells localized in the immune system. We have recently shown that the constitutive levels of NGF undergo trough significant changes during inflammatory conditions and in neuroimmune pathologies. We have also reported that autoimmune inflammatory disorders are characterized by a disregulation of synthesis and utilization of NGF. Though the mechanisms implicated in these events are not yet known, there emerging evidence indicating this polypeptide can play an important role in healing processes within the nervous and cutaneous tissues and in inflammatory conditions.

Animals↗
PubMed2001

NGF, BDNF, leptin, and mast cells in human coronary atherosclerosis and metabolic syndrome.

While multiple growth factor, cytokines, and immune cells are identified in atherosclerotic lesions, as well as an essential nonneuronal function of neurotrophins implicated in cardiovascular tissue development and in lipid and glucose metabolism, the role of the neurotrophins NGF and BDNF and also the adipokine leptin in human coronary atherosclerosis and related disorders, such as metabolic syndrome, remains unclear. Here we report that (i) both the amount and the immunoreactivity of NGF was reduced and the expression of p75NGF receptor and the number of mast cell increased in human atherosclerotic coronary arteries (n = 12) compared with control specimens (n = 9) obtained from autopsy cases, and (ii) NGF and BDNF plasma levels were reduced in patients with metabolic syndrome (n = 23) compared with control subjects (n = 10). Also, in metabolic syndrome patients, a positive correlation between the plasma leptin levels and the number of adipose tissue mast cells was found, suggesting that leptin may be a novel adipoimmune mediator. Altogether, the results provide the first correlative evidence for the potential involvement of NGF, BDNF, leptin, and mast cells in human coronary atherosclerosis and metabolic syndrome, implying neuroimmune and adipoimmune pathways in the pathobiology of these cardiovascular disorders.

Brain-Derived Neurotrophic Factor↗
PubMed2001

Neuroinflammatory implication of Schistosoma mansoni infection in the mouse.

Schistosomiasis is a parasitic disease due to Schistosoma mansoni. Schistosome infection is known to induce granulomas not only in the spleen, bladder, liver and intestine but also in the brain and spinal cord resulting in severe neuropathological and psychiatric disorders though the interaction between Schistosoma mansoni infection and the nervous system has received on the whole little attention. In the present review it has been discussed recent findings from experimental Schistosoma mansoni infection in mouse nervous system. We show that brain granulomas are associated with a significant alteration in the constitutive levels of nerve growth factor (NGF), a trophic factor playing an essential role in nerve growth and differentiation and in preventing neuronal damages. Animals infected with schistosomes suffered also of increased pain sensitivity which was inhibited by TNF-alpha antibody injections and not by anti-NGF. These findings suggest that the neuropathological dysfunctions in neuroschistosomiasis may be linked to changes in the basal levels and/or activity of neurotrophic factors caused by local formation of granulomas.

Animals↗
PubMed2001

Nerve growth factor and neuropeptides circulating levels in systemic sclerosis (scleroderma).

OBJECTIVE: To determine the circulating levels of nerve growth factor (NGF), neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP) in systemic sclerosis (SSc), and to correlate these levels with clinical and laboratory features. METHODS: Forty four patients with SSc were evaluated for circulating NGF (immunoenzymatic assay), NPY and VIP (radioimmunoassay), anticentromere and antitopoisomerase I autoantibodies, lung disease (pulmonary function tests with carbon monoxide transfer factor (TLCO), ventilation scintiscan with 99mTc DTPA radioaerosol, high resolution computed tomography (HRCT), pulmonary pressure (echo colour Doppler)), heart disease (standard and 24 ECG, echocardiography), cutaneous involvement (skin score), joint involvement (evidence of tender or swollen joints, or both), peripheral nervous system (PNS) involvement (electromyography), rheumatoid factor, angiotensin converting enzyme (fluorimetric method), von Willebrand factor (ELISA), and erythrocyte sedimentation rate (ESR) (Westergren). RESULTS: Circulating NGF levels in SSc were significantly increased compared with controls (p<0.00001) and significantly higher in the diffuse than in the limited subset of patients (p<0.01). Patients with articular disease had significantly higher levels of NGF. A significant indirect correlation between NGF levels and TLCO was detected (p<0.01), but no correlation was found between NGF and HRCT, DTPA, skin score, PNS involvement and angiotensin converting enzyme and von Willebrand factor levels, antitopoisomerase or anticentromere antibodies, and ESR. NGF levels increased progressively as the disease worsened. Similarly, VIP circulating levels were significantly increased in patients with SSc (p<0.001), whereas the increase of NPY levels did not reach statistical significance. However, both neuropeptides, following the same trend as NGF, increased as the disease worsened (skin score and lung disease). CONCLUSIONS: The increase of NGF and VIP in patients with SSc, the former in the diffuse subset of the disease, and in patients with prominent articular disease, may suggest a link between neurotransmitters and the disease pathogenesis. Neuropeptide circulating levels seem to increase only in patients with the most severe disease.

Biomarkers↗
PubMed2001

Nerve growth factor in neurological and non-neurological diseases: basic findings and emerging pharmacological prospectives.

Nerve growth factor (NGF) is known to be essential for the survival of peripheral and brain neurons, and according to more recent studies also for a variety of cells localized in the immune system. Basic and preclinical findings published in the last 15-20 years have prospected the hypothesis that NGF can be pharmaceutically useful for promoting healing in certain peripheral and central neurological insults. We have recently provided evidence that NGF applied topically, has a therapeutic potentiality for human corneal and pressure ulcers, and more recently in vasculitis induced by rheumatoid arthritis. This review will summarize previous and ongoing evidence supporting the role of NGF in the nervous and immune system and discuss NGF potentiality as a pharmacological tool for basic and clinical studies.

Animals↗
PubMed2001

Presence and possible functional role of nerve growth factor in the thymus.

We have previously reported that the nerve growth factor (NGF), a polypeptide known for its neurotrophic activities, is also involved in proliferation, growth and survival of cells of the immune system. Working with animal models, we found that NGF and NGF-receptors (NGF-r) are present in the cells of the medullary layer of the thymus, a lymphoid gland involved in the production and differentiation of T-lymphocytes. Using immunohistochemical and biochemical approaches, we also showed that the expression of NGF in the thymus is high during late prenatal life and decreases later in postnatal life. A significant alteration of NGF levels was also found during pregnancy and aging, two events characterized by thymic involution. The aim of this study is to investigate whether NGF and NGF-r expression in the thymus are influenced by immuno- and neuro-pathological events. These observations will be presented and discussed.

Animals↗