[Changes in nerve growth factor levels related to age and neurotrophic treatment in non-human primate]. / Cambios en los niveles de factor de crecimiento nervioso con el envejecimiento y el tratamiento neurotrófico en primates no humanos.

INTRODUCTION: To examine the amounts and role of growth factors in different tissues and corporal fluid, new sensitive techniques have to be developed. A major problem is that the normal concentration of trophic substances, such as nerve growth factor (NGF), in central and peripheral nervous system and in fluids is very low (ng pg/ml). A valuable method of research is the sensitive two site enzyme immunoassay using the monoclonal antibody 27/21 to mouse NGF. Materials and methods. The present work applied this enzyme immunoassay to examine the NGF levels in normal non human primate sera (n= 94) and applied this assay to study of NGF levels in two non human primate receiving NGF infusion: one young and one aged. Two groups of non human primate sera were studied one young adult (n= 69) and one aged (n= 25). The serum samples NGF treated non human primate were taken before the infusion and at the 1st week and 1st, 3rd, 6th and 12th month after infusion. RESULTS: To further test the specificity of conjugate binding, dilutions of the non human primate sera were preincubated with an excess of monoclonal NGF antibody 27/21 in solution. With this strategy it was possible to completely block the signal obtained using the enzyme immunoassay. We found very low levels of NGF in aged monkeys (0.054 ng/ml) when compared with young adult group (0.152 ng/ml) (p> 0.01). The NGF levels in aged non human primate treatment with NGF was very low before (0.50 ng/ml) and during NGF treatment evolution time, whereas at the the 12th month showed an increase in NGF levels (0.180 ng/ml). We found normal values of NGF in the young monkey before and during the first year after NGF infusion. CONCLUSIONS: Using the enzyme immunoassay described it is possible to know the serum concentration of NGF immunoreactive in non human primate and this assay is able to detect peripheral changes in NGF levels after intracerebral infusion of NGF.

Behavioral and biochemical effects of glutathione depletion in the rat brain.

Glutathione serves the function of providing reducing equivalents for the maintenance of oxidant homeostasis, and besides it plays roles in intra- and intercellular signaling in the brain. Our purpose was to test the effects of depleting tissue glutathione by diethylmaleate (5.3 mmol/kg, intraperitoneal) on brain antioxidant metabolism, nerve growth factor levels, and cognitive performance in rats. Six hours after the treatment, glutathione level in the hippocampus dropped down to 30% of the mean value of vehicle-treated animals and glutathione peroxidase activity also declined. Twenty-four hours after the injection the values had been partially restored. Moreover, the hippocampal and cortical levels of nerve growth factor protein did not change in response to diethylmaleate treatment. Glutathione depletion did not influence the performance of animals in the step-through passive avoidance test, but impairs acquisition in the Morris water maze when given before training. However, when diethylmaleate was administered after acquisition in the same paradigm, it did not affect the retention tested at the following day. Our results suggest that glutathione status is important during acquisition, but not for retention, of spatial memory in maze tasks and they support the hypothesis of the oxidant/antioxidant equilibrium as a key piece acting in the regulation of brain function.

[Factors that lead to death of neurons in neurodegenerative diseases]. / Factores que desencadenan la muerte neuronal en enfermedades neurodegenerativas.

OBJECTIVE: The objective of this paper was to review information related to the various factors which may trigger the mechanisms of cell death, induced or programmed, which take place in the nervous system and their relationship with the aetiopathogenesis of the neurodegenerative diseases. DEVELOPMENT: In recent years it has been recognized that cell death may be not only the consequence of accidental damage but also a sign of a suicide programme. This form of death is currently known as apoptosis. It is a process which is morphologically distinct from accidental cell death or necrosis. It does not cause an inflammatory response. This type of death is not only involved in the development and haemostasis of tissues, but also in setting off neuronal degeneration in experimental models of Parkinson's disease, Huntington's chorea, etc. CONCLUSIONS: In the cell death occurring in neurodegenerative diseases there is more than one induction mechanisms. Understanding the factors which trigger cell death, and the chain of events leading to this, gives grounds for the design of new pharmacological strategies for the treatment of these diseases.

[Obtention and characterization of murine beta-NGF. Application in a model of cerebral aging]. / Obtención y caracterización del beta-NGF murino. Aplicación en un modelo de envejecimiento cerebral.

INTRODUCTION: beta-NGF is a basic protein of 118 aminoacids which acts are a trophic factor for sensory and sympathetic neurons of the peripheral nervous system, and on cholinergic neurons of the anterior basal cerebrum. OBJECTIVES: In view of the functional effect of beta-HGF and its possibilities as a therapeutic agent in neurodegenerative disease, including Alzheimer's disease in this study our aim was to obtain, characterize and show the main results of the application of beta-NGFm in a model of cerebral ageing in rats with cognitive disorders. MATERIAL AND METHODS: For the obtention of beta-NGFm we followed Mobley's method as modified by Ebendal and used mouse submaxillary gland as a source of raw material. The characterization studies were carried out by application of seven techniques which allowed physicochemical characterization and demonstration of the biological activity of the product. Application of beta-NGF obtained under these conditions was carried out in a mode of cerebral ageing and the effects of treatment were assessed by conduct studies, measurement of the activity of the enzyme acetyl cholinesterase and study of neural plasticity. CONCLUSIONS: Characterization studies carried out on the beta-NGFm showed that the protein obtained consists of a mixture of molecules of beta-NGFm which are intact at their extreme N-Terminal, and molecules which have lost the octapeptide of the N-terminal position and show some modification increasing hydrophobicity. All these species were recognized immunologically by the specific antibody anti-NGFm and showed biological activity.

[Nerve growth factor and neurological diseases]. / Factor de crecimiento nervioso y enfermedades neurológicas.

INTRODUCTION: The effects of Nerve Growth Factor (NGF) within and outside the nervous system have been amply discussed in recent decades. Recently clinical studies have shown the effectiveness of this growth factor in the treatment of neurodegenerative disorders. This clinical use makes it necessary to have sensitive, specific methods available to permit measurement of the level of this protein and to determine how it behaves during the course of treatment. OBJECTIVE: To describe the measurement of NGF levels in human serum using an immunoenzymatic method and evaluating the levels of this protein in some neurological disorders. Materials and methods. NGF levels were measured in the serum of healthy persons and in patients with Alzheimer's disease (AD) Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS) and Huntington's chorea (HC) using a double site immune-enzymatic assay. Murine 27/21 anti-beta-NGF monoclonal antibody was used as the antibody to cover the plate and as conjugate. RESULTS: Adding a block pass to the method, in which the sample was incubated with an excess of 27/21 antibody effectively reduced the signal observed in the immuno-enzymatic assay. A moderate reduction in beta-NGF levels was seen in the serum of patients with ALS and MS. There was a statistically significant reduction in the patients who were carriers of PD and HC. CONCLUSIONS: The significant reduction in NGF levels in patients with PD and HC may be associated with a disorder in the use of this protein in central and peripheral tissues.

Factor de crecimiento nervioso y enfermedades neurológicas / Nerve growth factor and neurological diseases

Introducción. Los efectos del factor de crecimiento nervioso (NGF, Nerve Growth Factor) dentro y fuera del sistema nervioso son ampliamente discutidos en las últimas décadas. Recientemente algunos estudios clínicos han demostrado la efectividad de este factor de crecimiento como tratamiento en enfermedades neurodegenerativas. Este uso clínico va necesariamente aparejado con la necesidad de contar con métodos sensibles y específicos que permitan cuantificar los niveles de esta proteina y conocer cómo se comportan los mismos durante la evolución del tratamiento. Objetivo. Describir la cuantificación del NGF en suero humano mediante el empleo de un método inmunoenzimático y evaluar los niveles de esta proteina en algunas enfermedades neurológicas. Material y métodos. Los niveles de NGF fueron cuantificados en suero de pacientes sanos y de pacientes con enfermedad de Alzheimer (EA), enfermedad de Parkinson (EP), esclerosis lateral amiotrófica (ELA), esclerosis múltiple (EM) y corea de Huntington (CH) mediante la utilización de un ensayo inmunoenzimático de doble sitio. Se utilizó el anticuerpo monoclonal anti B-NGF 27/21 murino como anticuerpo recubridor de la placa y como conjugado. Resultados. La adición al método de un paso de bloqueo, donde se incuba la muestra con un exceso de anticuerpo 27/21, redujo de manera efectiva la señal observada en el ensayo inmunoenzimático. Se evidenció una disminución moderada en los niveles de B-NGF en suero de pacientes con ELA y EM, y una disminución estadísticamente significativa en los pacientes portadores de EP y CH. Conclusiones. La disminución significativa en los niveles de NGF en pacientes con EP y CH puede estar relacionada con una alteración en la utilización de esta proteina en tejidos centrales o periféricos

Nerve growth factor levels in normal human sera.

Nerve growth factor (NGF) is the best characterized of the neurotrophic factors, but there is incomplete information concerning its levels in body fluids. Normal values of NGF in serum from 157 normal subjects were determined by enzyme immunoassay (EIA). A mean NGF level of 194 +/- 25 pg ml-1 was obtained. There were no statistically significant variations with age, but the NGF level was significantly lower in females (112 +/- 31 pg ml-1) than in males (243 +/- 35 pg ml-1).

NGF in experimental models of Parkinson disease.

We have now applied the enzyme immunoassay using anti-NGF monoclonal antibody (MAb) 27/21 and a blocking test validating the specificity of the immunoreactivity for NGF in serum samples to examine NGF levels in normal rat sera, hemiparkinsonian rat sera, normal monkey sera, and MPTP-treated monkey sera. The levels of NGF in treated animals showed reductions when compared with serum from normal animals. The NGF level alterations observed in lesioned animals and in human parkinsonian patients evidence a relationship between this neurotrophic factor and the neurodegenerative changes observed in Parkinson disease (PD).

Nerve growth factor levels in normal human sera: study of the spontaneous motor activity in stumptailed monkeys

Nerve growth factor (NGF) is the best characterized of the neurotrophic factors, but there is incomplete information concerning its levels in body fluids. Normal values of NGF in serum from 157 normal subjets were determined by enzyme immunoassay (EIA). A mean NGF level of 194 ñ 25 pg ml-1 was obtained. There wee no statistically significant variations with age, but the NGF level was significantly lower in females (112 ñ 31 pg ml-1) than in males (243 ñ 35 pg ml-1)

NGF in experimental models of parkinson disease

We have now applied the enzyme immunoassay usin anti-NGF monoclonal antibody (MAb) 27/21 and a blocking test validating the specificity of the immunoreactivity for NGF in serum samples to examine NGF levels in normal rat sera, hemiparkinsonian rat sera, normal monkey sera, and MPTP-treated monkey sera. The levels of NGF in treated animals showed reductions when compared with serum from normal animals. The NGF level alterations observed in lesioned animals and in human parkinsonian patients evidence a relationship between this neurotrophic factor and the neurodegenerative changes observed in Parkinson disease

Evolutive levels of NGF in neurodegenerative disorders

The two-site enzyme immunoassasy (EIA) using the monoclonal antibody (MAb) 27/21 is a valuable method capable of detecting mouse and human NGF quantitatively (Soderstrom et al., 1990). The presence of NGF in serum has been controversial, since t6he previous assay methods failed to detect circulating NGF. Recently, we described the immunological detection of low levels of NGF in human serum samples and introduced a blocking test validating the specificity of the immunoreactivity for NGF in human serum (Lorigados et al., 1982). In the present work, we applied this two-site EIA using monoclonal NGF antibody 27/21 in the study of NGF serum levels from diverse neurodegenerative disorders. We also studied evolutive samples of Parkinson's patients that received neural transplant

[Immunologic changes in sickle-cell anemia]. / Alteraciones inmunológicas en la anemia drepanocítica.

In order to assess the status of their immunologic system, a study was carried out in 38 adults with sickle-cell anaemia. Fifty healthy blood donors were used as control group. Significant decrease of serum albumin (p less than 0.02) and increase of alpha-globulins (p less than 0.01) and gamma-globulins (p less than 0.001) were present in the patients. They showed also significantly decreased percentage of spontaneous rosette-forming lymphocytes (p less than 0.01) and of lymphocytes responding to anti-CD3 monoclonal antibody (p less than 0.05) with respect to the control group. Such relative T-cell decrease in peripheral blood seemingly took place by means of decreasing CD4-positive subpopulations, whose percentage was significantly lower (p less than 0.001) in the patients than in the control subjects. Functional studies showed a significant decrease (p less than 0.001) of the activity of natural cytotoxic cells. None of the patients had antibodies against human immunodeficiency viruses type 1 and type 2, and 60% of them were positive to cytomegalovirus test. No statistical correlation was found between the immunological findings and the presence of antibodies against such virus, neither such alterations correlated with the number of blood units received by the patients.