The ALIAmide palmitoylethanolamide and cannabinoids, but not anandamide, are protective in a delayed postglutamate paradigm of excitotoxic death in cerebellar granule neurons

The amino acid L-glutamate is a neurotransmitter that mediates fast neuronal excitation in a majority of synapses in the central nervous system. Glutamate stimulates both N-methyl-D-aspartate (NMDA) and non-NMDA receptors. While activation of NMDA receptors has been implicated in a variety of neurophysiologic processes, excessive NMDA receptor stimulation (excitotoxicity) is thought to be primarily responsible for neuronal injury in a wide variety of acute neurological disorders including hypoxia-ischemia, seizures, and trauma. Very little is known about endogenous molecules and mechanisms capable of modulating excitotoxic neuronal death. Saturated N-acylethanolamides like palmitoylethanolamide accumulate in ischemic tissues and are synthesized by neurons upon excitatory amino acid receptor activation. Here we report that palmitoylethanolamide, but not the cognate N-acylamide anandamide (the ethanolamide of arachidonic acid), protects cultured mouse cerebellar granule cells against glutamate toxicity in a delayed postagonist paradigm. Palmitoylethanolamide reduced this injury in a concentration-dependent manner and was maximally effective when added 15-min postglutamate. Cannabinoids, which like palmitoylethanolamide are functionally active at the peripheral cannabinoid receptor CB2 on mast cells, also prevented neuron loss in this delayed postglutamate model. Furthermore, the neuroprotective effects of palmitoylethanolamide, as well as that of the active cannabinoids, were efficiently antagonized by the candidate central cannabinoid receptor (CB1) agonist anandamide. Analogous pharmacological behaviors have been observed for palmitoylethanolamide (ALI-Amides) in downmodulating mast cell activation. Cerebellar granule cells expressed mRNA for CB1 and CB2 by in situ hybridization, while two cannabinoid binding sites were detected in cerebellar membranes. The results suggest that (i) non-CB1 cannabinoid receptors control, upon agonist binding, the downstream consequences of an excitotoxic stimulus; (ii) palmitoylethanolamide, unlike anandamide, behaves as an endogenous agonist for CB2-like receptors on granule cells; and (iii) activation of such receptors may serve to downmodulate deleterious cellular processes following pathological events or noxious stimuli in both the nervous and immune systems.

Nerve growth factor in the anterior pituitary: localization in mammotroph cells and cosecretion with prolactin by a dopamine-regulated mechanism

Nerve growth factor (NGF) is well characterized for its neurotrophic actions on peripheral sensory and sympathetic neurons and on central cholinergic neurons of the basal forebrain. Recent evidence, however, has shown high levels of NGF to be present in a variety of biological fluids after inflammatory and autoimmune responses, suggesting that NGF is a mediator of immune interactions. Increased NGF serum levels have been reported in both humans and experimental animal models of psychological and physical stress, thus implicating NGF in neuroendocrine interactions as well. The possible source(s) and the regulatory mechanisms involved in the control of serum NGF levels, however, still remain to be elucidated. We now report the presence of both NGF gene transcripts and protein in the anterior pituitary. Immunofluorescence analysis indicated that hypophysial NGF is selectively localized in mammotroph cells and stored in secretory granules. NGF is cosecreted with prolactin from mammotroph cells by a neurotransmitter-dependent mechanism that can be pharmacologically regulated. Activation of the dopamine D2 receptor subtype, which physiologically controls prolactin release, resulted in a complete inhibition of vasoactive intestinal peptide-stimulated NGF secretion in vitro, whereas the specific D2 antagonist (-)-sulpiride stimulated NGF secretion in vivo, suggesting that the anterior pituitary is a possible source of circulating NGF. Given the increased NGF serum levels in stressful conditions and the newly recognized immunoregulatory function of this protein, NGF, together with prolactin, may thus be envisaged as an immunological alerting signal under neuronal control.

N-(2-hydroxyethyl)hexadecanamide is orally active in reducing edema formation and inflammatory hyperalgesia by down-modulating mast cell activation

Mast cells play a key role in inflammatory reactions triggered by tissue injury or immune perturbations. Little is known about endogenous molecules and mechanisms capable of modulating inappropriate mast cell activity. N-(2-Hydroxyethyl)hexadecanamide (palmitoylethanolamide), found in peripheral tissues, has been proposed to act as a local autacoid capable of negatively regulating mast cell activation and inflammation-hence the acronym Autacoid Local Inflammation Antagonism (ALIA). Recently, N-(2-hydroxyethyl)hexadecanamide (LG 2110/1) has been reported to down-modulate mast cell activation in vitro by behaving as an agonist at the peripheral cannabinoid CB2 receptor. Here, we have characterized and functionally correlated the anti-inflammatory actions of LG 2110/1 with its ability to control mast cell activation, when given orally in a battery of rodent models of inflammation. LG 2110/1 diminished, in a dose-dependent and correllated manner, the number of degranulated mast cells and plasma extravasation induced by substance P injection in the mouse ear pinna. In addition, LG 2110/1 reduced dose dependently plasma extravasation induced by passive cutaneous anaphylaxis reaction. In adult rats LG 2110/1 decreased, in a dose-dependent manner, carrageenan-induced hindpaw edema and hyperalgesia, but not phospholipase A2-induced hindpaw edema. Further, anti-edema effects were observed when utilizing dextran and formalin, known to also cause mast cell activation. Locally administered LG 2110/1 was likewise effective in minimizing dextran-induced hind paw edema. In contrast, equivalent amounts of palmitic acid plus ethanolamine were ineffective against plasma extravasation provoked by substance P. LG 2110/1 did not decrease plasma extravasation induced by the substance P fragment, substance P-(6-11), known to be inactive on mast cells. These results indicate that orally administered N-(2-hydroxyethyl)hexadecanamide is effective in: (a) directly down-modulating mast cell activation in vivo; (b) suppressing pathological consequences initiated by mast cell activation independently of the activating stimuli; (c) exerting an anti-inflammatory action distinguishable from that of classical steroidal and non-steroidal anti-inflammatory agents. These findings raise the possibility that N-(2-hydroxyethyl)hexadecanamide and related saturated N-acylamides ('ALIAmides') represent novel therapeutic agents useful in the management of inflammatory disease conditions.

Importance of psychotic features to long-term course in major depressive disorder

OBJECTIVE

Most efforts to describe the prognostic significance of psychotic features in depression have been limited to single assessments 1 year or less after the initial evaluation. However, the various biological and treatment response differences between patients with psychotic and nonpsychotic depression suggest that prognostic differences may be very long-term.

METHOD

The 787 patients described here entered the study as they sought treatment at one of five academic medical centers; they had either RDC major depressive disorder or schizo-affective depression (other than the mainly schizophrenic subtype) and completed at least 6 months of follow-up. Of these, 144 (18.3%) had psychotic depression as defined here. Patients provided follow-up interviews at 6-month intervals for 5 years and annually thereafter; 98 of those with psychotic depression and 434 of those with non-psychotic depression were followed for 10 years.

RESULTS

Those who began follow-up with psychotic depression had fewer weeks with minimal symptoms in each of the 10 years of follow-up and reported more psychosocial impairment at both 5 and 10 years. Both the index episode and the first recurrence of psychotic depression lasted longer than nonpsychotic episodes, but nonpsychotic episodes among previously psychotic individuals were relatively brief. Intervals between episodes were significantly shorter for patients who had ever been psychotic.

CONCLUSIONS

Together with evidence that psychotic features are highly recurrent, these data show 1) that psychotic features denote a lifetime illness of greater severity and 2) that within individuals, psychotic features may emerge in only the more severe episodes.

Mast cell activation causes delayed neurodegeneration in mixed hippocampal cultures via the nitric oxide pathway

Mast cells are pleiotropic bone marrow-derived cells found in mucosal and connective tissues and in close apposition to neurons, where they play important roles in tissue inflammation and in neuroimmune interactions. Connective tissue mast cells, with which intracranial mast cells share many characteristics, contain cytokines that can cause inflammation. Here, we report that myelin basic protein, a major suspected immunogen in multiple sclerosis, as well as an antigenic stimulus, provokes mast cells to trigger a delayed cytotoxicity for neurons in mixed neuron-gila cultures from hippocampus. Neurotoxicity required a prolonged period (12 h) of mast cell incubation, and appeared to depend largely on elaboration of the free radical nitric oxide by astrocytes. Activation of astrocytes was mediated, in part, by mast cell-secreted tumor necrosis factor-alpha. Myelin basic protein and 17 beta-estradiol had a synergistic action on the induction of mast cell-associated neuronal injury. The cognate mast cell line RBL-2H3, when subjected to an antigenic stimulus, released tumor necrosis factor-alpha which, together with exogenous interleukin-1 beta (or interferon-gamma), induced astroglia to produce neurotoxic quantities of nitric oxide. A small but significant proportion of mast cell-derived neurotoxicity under the above conditions occurred independently of glial nitric oxide synthase induction. Further, palmitoylethanolamide, which has been reported to reduce mast cell activation by a local autacoid mechanism, decreased neuron loss resulting from mast cell stimulation in the mixed cultures but not that caused by direct cytokine induction of astrocytic nitric oxide synthase. These results support the notion that brain mast cells could participate in the pathophysiology of chronic neurodegenerative and inflammatory diseases of the nervous system, and suggest that down-modulation of mast cell activation in such conditions could be of therapeutic benefit.

Holoprosencephaly with proboscis

This is the case of a male newborn with holoprosencephaly, marked hypotelorism, and a rudimentary nasal structure, the proboscis. The head CT scan showed a single monoventricle and two ocular globes fused at the midline. Chromosome studies showed a normal karyotype. The importance of ultrasonography in the prenatal diagnosis of this malformation is presented.

Lesion topography and new histological features in feline taurine deficiency retinopathy

Previous studies of feline taurine deficiency retinopathy have established that the retinopathy begins as a focal lesion at the area centralis (feline central retinal degeneration) and progresses to form a horizontal band of retinal degeneration which, in some cases, eventually involves the whole retina. Several theories have been proposed to account for the strikingly unusual geographic distribution of lesions in this disease, including a preferential cone photoreceptor effect, and damage by exposure to light. In this paper evidence is provided that the regional lesions in advanced cases of taurine deficiency retinopathy extend circumferentially to form a peripheral annular band-like arrangement around the retinal extremity. The circumferential annulus is confluent with both temporal and nasal extremes of the horizontal band-shaped lesion. The topographic arrangement of the advanced lesion thus approximates the shape of the Greek letter theta, theta. A previously unreported sclerad displacement of photoreceptor cells into the subretinal space was commonly observed histologically. Radially sectioned material also revealed pathological changes in photoreceptors over a much more widespread region than the focal lesions observable ophthalmoscopically and in whole-mounts of the retina. The issue is therefore to account for the advanced photoreceptor cell loss in the focal lesions. A preferential effect on cone photoreceptors is insufficient to explain the lesion distribution, and unilateral tarsorrhaphy experiments exclude light damage as a major factor. Some other factor, or combination of factors, is most likely involved in determining the unique geographic distribution of lesions in feline taurine deficiency retinopathy.

Does physical improvement reduce depressive symptoms in HIV-infected medical inpatients?

The Beck Depression Inventory, Karnofsky Scale of Physical Performance, and a visual-analogue scale to assess subjective distress were administered to 32 HIV-infected medical inpatients shortly after admission and prior to discharge. Twenty-eight percent of subjects had severe depressive symptoms on admission. Most of these subjects remained in the severe range of depressive symptoms at discharge, despite physical improvement comparable to subjects with lower levels of depressive symptoms. In contrast, subjects with moderate depressive symptoms on admission showed a significant decrease in depressive symptoms at discharge. The results suggest that the etiology and management of depressive symptoms in HIV-infected medical inpatients may differ depending on the initial severity of depressive symptoms.

Characteristics and significance of untreated major depressive disorder

OBJECTIVE

This study sought to describe the characteristics and consequences of untreated major depressive disorder.

METHOD

As part of a family study of probands with major affective disorders, raters assessed 3,119 first-degree relatives, spouses, and comparison subjects. When 2,237 (71.7%) of these individuals were reassessed 6 years later, 547 had experienced episodes of major depressive disorder in the interval. Those who had sought any form of treatment for any episode of major depressive disorder in the interval were compared, by baseline demographic characteristics and clinical features of their worst episodes of major depressive disorder, to those who had not. Individuals who had had untreated major depressive disorder were then compared, by changes in socioeconomic status and by levels of psychosocial impairment at follow-up, to a matched group with no major depressive disorder in the interval.

RESULTS

The worst episodes of 313 treated individuals, compared to those of 234 untreated individuals, were characterized by older age, symptoms of the endogenous subtype, longer durations, and the presence of disruption in role function. Each of these factors contributed independently to the distinction between treated and untreated episodes. Untreated individuals experienced significant psychosocial impairment on follow-up but did not show the economic disadvantages shown elsewhere for probands who began follow-up as they sought treatment at tertiary medical centers.

CONCLUSIONS

These data suggest that illness characteristics and age determine the decision to seek treatment for major depressive disorder. Untreated depression is apparently associated with long-standing psychosocial difficulties but not with serious economic consequences.

Update of the NGF saga

Nerve growth factor (NGF), initially characterized for its survival and differentiating actions on embryonic sensory and sympathetic neurons, is now known to display a greatly extended spectrum of biological functions. NGF exerts a profound modulatory role on sensory nociceptive nerve physiology during adulthood which appears to correlate with hyperalgesic phenomena occurring in tissue inflammation. Other newly detected NGF-responsive cells belong to the hematopoietic-immune and neuroendocrine systems. In particular, mast cells and NGF both appear to be involved in neuroimmune interactions and tissue inflammation, with NGF acting as a general "alert" molecule capable of recruiting and priming both local tissue and systemic defense processes following stressful events. NGF can thus be viewed as a multifactorial mediator modulating neuroimmune-endocrine functions of vital importance to the regulation of homeostatic interactions, with potential involvement in pathological processes deriving from dysregulation of either local or systemic homeostatic balances.

A family study of manic-depressive (bipolar I) disease. Is it a distinct illness separable from primary unipolar depression?

OBJECTIVE

To determine whether bipolar I illness is autonomous or part of a multifactorial continuum with unipolar depression. In this study, we compare familial bipolar I illness and depression among three groups: probands with bipolar I disorder; probands with primary unipolar disorder; and controls. We also examine a continuum of severity between psychotic and nonpsychotic patients with bipolar I disorder. Considerable data suggest that bipolar I illness is distinct from unipolar illness as regards epidemiology, familial psychiatric illness, course, response to treatment, and biologic findings.

METHOD

Probands were separated into bipolar I and primary unipolar depressive groups. Personally interviewed family members of these patients were compared on variables of bipolar illness or schizoaffective mania and unipolar or schizoaffective depression. A personally examined control group was compared with the relatives of the two proband groups. Similar analyses were performed using data obtained by a systematic family history method. For the same familial variables, psychotic and nonpsychotic manic probands were compared.

RESULTS

Familial mania is more frequent in families of patients with bipolar disease than in controls or in families of patients with primary unipolar disorder. The latter two groups did not differ in amount of mania. Unipolar depressive illness or schizoaffective depression was higher in families of probands with bipolar and unipolar disorder than in controls. Probands with bipolar disease separated into those who had psychotic symptoms (including schizoaffective mania) and no psychotic symptoms did not differ from each other in risk for familial mania or depression.

CONCLUSIONS

Bipolar I illness is a separate illness from primary unipolar illness because of an increase in familial mania. Patients with primary unipolar disease and controls show the same amount of familial mania. Lack of an increase in familial illness according to the severity of bipolar disease is against an affective continuum.

Mast cells express a peripheral cannabinoid receptor with differential sensitivity to anandamide and palmitoylethanolamide

Mast cells are multifunctional bone marrow-derived cells found in mucosal and connective tissues and in the nervous system, where they play important roles in tissue inflammation and in neuroimmune interactions. Very little is known about endogenous molecules and mechanisms capable of modulating mast cell activation. Palmitoylethanolamide, found in peripheral tissues, has been proposed to behave as a local autacoid capable of downregulating mast cell activation and inflammation. A cognate N-acylamide, anandamide, the ethanolamide of arachidonic acid, occurs in brain and is a candidate endogenous agonist for the central cannabinoid receptor (CB1). As a second cannabinoid receptor (CB2) has been found in peripheral tissues, the possible presence of CB2 receptors on mast cells and their interaction with N-acylamides was investigated. Here we report that mast cells express both the gene and a functional CB2 receptor protein with negative regulatory effects on mast cell activation. Although both palmitoylethanolamide and anandamide bind to the CB2 receptor, only the former downmodulates mast cell activation in vitro. Further, the functional effect of palmitoylethanolamide, as well as that of the active cannabinoids, was efficiently antagonized by anandamide. The results suggest that (i) peripheral cannabinoid CB2 receptors control, upon agonist binding, mast cell activation and therefore inflammation; (ii) palmitoylethanolamide, unlike anandamide, behaves as an endogenous agonist for the CB2 receptor on mast cells; (iii) modulatory activities on mast cells exerted by the naturally occurring molecule strengthen a proposed autacoid local inflammation antagonism (ALIA) mechanism; and (iv) palmitoylethanolamide and its derivatives may provide antiinflammatory therapeutic strategies specifically targeted to mast cells ("ALIAmides").

Inflammatory mediator stimulation of astrocytes and meningeal fibroblasts induces neuronal degeneration via the nitridergic pathway

The role of inflammatory cytokines in the pathogenesis of neurological disorders is not entirely clear. The neurotoxic effects of cytokines, and perhaps indirectly bacterial endotoxins, could be mediated by the stimulation of immunocompetent cells in the brain to produce toxic concentrations of nitric oxide (NO) and reactive nitrogen oxides. NO is a short-lived, diffusible molecule that has a variety of biological activities including vasorelaxation, neurotransmission, and cytotoxicity. Both constitutive and inducible NO synthase has been described in astrocytes in vitro. Here we demonstrate that newborn mouse cortical astrocytes, when coincubated with neonatal mouse cerebellar granule cells or hippocampal neurons, induced neurotoxicity upon stimulation with endotoxin (lipopolysaccharide) (ED50 30 ng/ml). Astrocytes were unresponsive to the cytokines tumor necrosis factor-alpha or interleukin-1 beta individually, but exhibited a marked synergistic stimulation in their combined presence. Moreover, meningeal fibroblasts treated with tumor necrosis factor-alpha, but not interleukin-1 beta or lipopolysaccharide, elaborated neurotoxicity for cocultured granule cells (ED50 30 U/ml). In cocultures of immunostimulated astrocytes or meningeal fibroblasts, neurotoxicity was blocked by the NO synthase inhibitors N omega-nitro-L-arginine and N omega-nitro-D-arginine methyl ester, and by oxyhemoglobin, which inactivates NO. Astroglial-induced neurotoxicity was not affected by N-methyl-D-aspartate receptor antagonists. Superoxide dismutase, which degrades superoxide anion, attenuated astrocyte- and fibroblast-mediated neurotoxicity, indicating that endogenous superoxide anion may react with NO to form toxic peroxynitrite and its breakdown products. These findings suggest a potentially important role for glial- and meningeal fibroblast-induced NO synthase in the pathophysiology of CNS disease states of immune or inflammatory origin.

Extracorporeal photochemotherapy: evaluation of two techniques and use in connective tissue disorders

Extracorporeal photochemotherapy (ECP) consists of collection of mononuclear cells, their irradiation with UV-A light in the presence of a photoactivable molecule--8-methoxy-psoralen (8-MOP) being the most widely used--and their reinjection into a patient. Two technical approaches have been developed. The photopheresis procedure involves four steps: (i) 8-MOP is given to the patient orally, 2 h before collection of white blood cells; (ii) a discontinuous flow cell separator (UVAR, Therakos, West Chester, PA, U.S.A.) is used for cell collection. The final product (740 mL) has a hematocrit of 4.5 +/- 1.7%); (iii) irradiation, performed with the same UVAR apparatus, begins before all the cells are collected, and lasts for 180 min after collection; and (iv) after irradiation, the buffy-coat is reinjected into the patient. We developed a technique summarized as follows: (i) mononuclear cell collection is performed using the Spectra (Cobe, Denver, CO, U.S.A.) cell separator, which provides a highly enriched mononuclear cell concentrate (always > 90% purity), in a small volume < 150 mL, subsequently adjusted to 300 mL for irradiation. Hematocrit of the final product is always < 2%. (ii) Soluble 8-MOP is added to the mononuclear cell concentrate at a final concentration of 200 ng/mL. (iii) Mononuclear cell concentrate is transferred in an EVA plastic bag (Macopharma, Tourcoing, France) to ensure an efficient irradiation with a UV irradiator (Vilber Lourmat, Marne-la-Vallée, France). (iv) After irradiation at 2 J/cm2 (time < 20 min), the cells are reinfused into the patient. Experimental and clinical data suggest that ECP has potential applications in the treatment of connective tissue disorders, such as systemic sclerosis and rheumatoid arthritis. Although encouraging data have been obtained, further clinical trials are warranted to establish the role of this therapy in these indications.

N-acetylaspartylglutamate selectively inhibits neuronal responses to N-methyl-D-aspartic acid in vitro

Canavan's disease is an autosomal recessive disorder characterized by a deficiency of aspartoacylase and accumulation of N-acetylaspartic acid (NAA), leading to a severe leukodystrophy and spongy degeneration of the brain. N-Acetylaspartylglutamate (NAAG), the presumed product of NAA, also accumulates in this disease. The endogenous dipeptide NAAG has been suggested to have low potency at NMDA receptors. Here we have tested the actions of NAAG and NAA on NMDA-evoked responses in cultured cerebellar granule cells. In differentiating granule cells grown in low-K+ medium, NAAG negated the survival-promoting effects of NMDA but not K+ depolarization. Neither NAAG nor NAA alone promoted cell survival in low-K+ medium. The modest trophic action of 50 microM kainic acid in low-K+ medium was reinforced by the NMDA receptor antagonist dizocilpine maleate and by NAAG. In K(+)-differentiated granule cells, NAAG raised the threshold of NMDA neurotoxicity but not that of kainate. The observed activities of NAAG were overcome by excess NMDA and were not mimicked by NAA. These data raise the possibility that disruption of NMDA receptor processes by NAAG may be of pathophysiological relevance.

Dopamine and the structure of personality: relation of agonist-induced dopamine activity to positive emotionality

Modern trait theories of personality include a dimension reflecting positive emotionality (PE) based on sensitivity to signals of incentive-reward. In animals, responsivity within an emotional system analog of PE is dependent on brain dopamine (DA) activity. To determine whether human PE trait levels are also associated with central DA, effects of a specific DA D2 receptor agonist were assessed in Ss who were widely distributed along the trait dimension of PE. The degree of agonist-induced reactivity in two distinct central DA indices was strongly and specifically associated with trait levels of PE, but not with other personality traits. The results suggest that the trait structure of personality may be related to individual differences in brain DA functioning.

Heat-loss response to a thermal challenge in seasonal affective disorder

This study extends earlier findings of poorly facilitated postexercise heat loss during the winter in seasonal affective disorder (SAD). While depressed in the winter, 19 SAD subjects exhibited a significantly impaired postexercise heat loss relative to 10 control subjects. During the summer while euthymic, SAD subjects did not significantly differ from control subjects in postexercise heat loss. Since thermoregulatory heat loss is a highly dopamine-dependent process, these results support earlier findings of poorly facilitated dopamine availability in SAD during the winter and suggest a centrally mediated effect of light in SAD.

Mast cells synthesize, store, and release nerve growth factor

Mast cells and nerve growth factor (NGF) have both been reported to be involved in neuroimmune interactions and tissue inflammation. In many peripheral tissues, mast cells interact with the innervating fibers. Changes in the behaviors of both of these elements occur after tissue injury/inflammation. As such conditions are typically associated with rapid mast cell activation and NGF accumulation in inflammatory exudates, we hypothesized that mast cells may be capable of producing NGF. Here we report that (i) NGF mRNA is expressed in adult rat peritoneal mast cells; (ii) anti-NGF antibodies clearly stain vesicular compartments of purified mast cells and mast cells in histological sections of adult rodent mesenchymal tissues; and (iii) medium conditioned by peritoneal mast cells contains biologically active NGF. Mast cells thus represent a newly recognized source of NGF. The known actions of NGF on peripheral nerve fibers and immune cells suggest that mast cell-derived NGF may control adaptive/reactive responses of the nervous and immune systems toward noxious tissue perturbations. Conversely, alterations in normal mast cell behaviors may provoke maladaptive neuroimmune tissue responses whose consequences could have profound implications in inflammatory disease states, including those of an autoimmune nature.

Anxiety psychopathology predictive of outcome in patients with panic disorder and depression treated with imipramine, alprazolam and placebo

This study examines clinical predictors of outcome for patients with panic disorder and depression in a 16 week, placebo-controlled trial of alprazolam and imipramine (n = 126). Baseline global severity of illness and phobic avoidance were differentially predictive of acute response to treatment. Patients in the mild to moderate range of global distress experienced smaller degrees of improvement on alprazolam than on imipramine at week 4. At endpoint, the relative effectiveness of the active medication versus placebo was diminished in patients with higher levels of phobic avoidance. This relationship was not evident for completers, suggesting that the adverse effects of avoidance on outcome after sustained treatment was reduced.

Parkinsonian serum carries complement-dependent toxicity for rat mesencephalic dopaminergic neurons in culture

The presence of antibodies recognizing specific epitopes of dopaminergic neurons in serum of patients suffering of Parkinson's Disease (PD) as well as their capability to induce neuronal damage was investigated utilizing serum-free dissociated mesencephalic-striatal co-cultures. High affinity dopamine (DA) and GABA uptakes were assessed as specific, functional markers of dopaminergic and GABAergic cell viability, respectively. Heat-inactivated serum samples from 18 and 13 patients suffering from idiopathic and vascular parkinsonism, respectively and from 18 neurologic controls, were added to co-cultures on day 4 in vitro. Twenty four hours later, reconstituted rabbit complement was added for 60 min and uptake parameters as well as immunocytochemical staining for tyrosine hydroxylase (TH)-containing cells were subsequently assessed. DA, but not GABA, uptake was significantly decreased only when complement was added to cultures containing serum samples from 14 out of 18 patients with idiopathic parkinsonism and 3 out of 13 patients with vascular parkinsonism (Fisher test, P < 0.01). Complement addition to cultures containing serum samples from seropositive parkinsonian patients significantly reduced immunocytochemical staining of TH-containing cells. Seropositive and seronegative patients did not differ in demographic and clinical features. These results suggest that a complement-dependent humoral immune response occurs mainly in idiopathic parkinsonian patients, but its clinical relevance remains to be established.

Nerve growth factor and autoimmune diseases

The initiation of a humoral immune response to a foreign antigen is a complex biologic process involving the interaction of many cell types and their secreted products. Autoimmune diseases, which are characterized by an abnormal activation of the immune system, probably result from the failure of normal self-tolerance mechanisms. The etiology of such illnesses, however, is far from being understood. While there have been extensive studies on the participation of the immune and endocrine systems in autoimmune diseases, few have dealt with nervous system-mediated immunoregulation in such situations. Evidence continues to grow suggesting that nerve growth factor (NGF), first identified for its activity in promoting the growth and differentiation of sensory and sympathetic neurons, may exert a modulatory role on neuroimmunoendocrine functions of vital importance in the regulation of homeostatic processes. Newly detected NGF-responsive cells belong to the hemopoietic-immune system and to populations in the brain involved in neuroendocrine functions. NGF levels are elevated in a number of autoimmune states, along with increased accumulation of mast cells. NGF and mast cells both appear to be involved in neuroimmune interactions and tissue inflammation. Moreover, mast cells themselves synthesize, store, and release NGF, proposing that alterations in normal mast cell behaviors may provoke maladaptive neuroimmune tissue responses whose consequences could have profound implications in inflammatory disease states, including those of an autoimmune nature. This review focuses on these cellular events and presents a working model which attempts to explain the close interrelationships of the neuroendocrinoimmune triade via a modulatory action of NGF.

Successful treatment of HIV-related vasculitis with peripheral neuropathy with short-term steroids followed by the association of zidovudine and plasmapheresis

OBJECTIVE

treatment of HIV-related vasculitis, avoiding prolonged immunosuppressive therapy.

DESIGN

prospective pilot study of HIV-related neurological vasculitis.

PATIENTS

two HIV-infected patients with histologically proven vasculitis.

INTERVENTION

short-term corticosteroid followed by zidovudine combined with plasmapheresis.

MAIN OUTCOME MEASURES

clinical, biological, immunological and electromyographic evaluation.

RESULTS

complete neurological recovery.

CONCLUSION

excellent tolerance and efficacy of combined zidovudine and plasmapheresis therapy in peripheral neurological HIV-related vasculitis.