Fabry disease: immunocytochemical characterization of neuronal involvement.

Fabry disease is an X-linked glycosphingolipid storage disease caused by deficiency of alpha-galactosidase. Storage of globotriaosylceramide, also known as ceramide trihexoside, is maximal in blood vessels but also occurs in neurons. We performed neuropathological histochemical studies on the brains and spinal cords of 2 patients with confirmed Fabry disease. Luxol fast blue-positive deposits were found in blood vessels throughout the central and peripheral nervous system and within selected neurons in spinal cord and ganglia, brainstem, amygdala, hypothalamus, and entorhinal cortex. Regions adjacent to involved neuronal groups, including nucleus basalis, striatum, globus pallidus, and thalamus, were spared. Electron microscopy showed lamellar cytoplasmic neuronal inclusion bodies. Using a monoclonal antibody reactive with ceramide trihexoside, we found more extensive neuronal deposition than evident by Luxol-fast blue staining and new areas of neuronal storage in the spinal cord and cerebral cortex. Blood vessels throughout the nervous system were strongly immunoreactive. The highly selective pattern of neuronal involvement we found suggests that glycosphingolipid exposure, uptake, or catabolism varies greatly with respect to neuronal morphology and distribution. The degree of toxicity to neurons and the clinical significance of this neuronal storage remains to be defined.     

Drug conditioning induced by intrastriatal apomorphine administration

The present study examined (1) whether the neostriatum is involved in a drug-induced conditioned locomotor response and; (2) whether this structure participates in the development of behavioral sensitization. Moreover, the present study addressed the question whether the development of behavioral sensitization is necessary for the induction of conditioning. Rats received injections of either apomorphine (2 μg) or vehicle (solution of 0.1% ascorbate/saline) into the dorsal neostriatum daily for 7 days. These treatments were performed immediately prior to (apomorphine-paired group and vehicle group) or 30 min following (apomorphine-unpaired group) 10-min placement in an open field which served as the test environment. After a 3-day drug withdrawal period, the animals were given a 10-min non-drug vehicle test trial in the test environment. Three days later, a drug test with apomorphine was administered to the animals of the paired and unpaired treatment groups; the vehicle group again received an injection of vehicle. The analysis of locomotor activity in the open field (measured as the distance traversed) revealed that locomotor activity in the apomorphine-paired group was higher than in the other groups. There were no indications for behavioral sensitization to intrastriatal apomorphine, since the locomotor response in the apomorphine-paired group did not increase, but rather decreased with daily repeated injections of apomorphine. Furthermore, only the apomorphine-paired animals showed a higher locomotor response when tested after an intrastriatal injection of vehicle in the previously apomorphine-paired environment, which is indicative of a conditioned drug effect. These results suggest that the neostriatum is directly involved in the development of drug-induced conditioning of locomotor behavior but not in the establishment of behavioral sensitization.     

The Mainz Severity Score Index: a new instrument for quantifying the Anderson-Fabry disease phenotype, and the response of patients to enzyme replacement therapy

Anderson-Fabry disease (AFD) is an X-linked disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. The availability of enzyme replacement therapy (ERT) for this debilitating condition has led to the need for a convenient and sensitive instrument to monitor clinical effects in an individual patient. This study aimed to develop a scoring system--the Mainz Severity Score Index (MSSI)--to measure the severity of AFD and to monitor the clinical course of the disease in response to ERT. Thirty-nine patients (24 males and 15 females) with AFD were assessed using the MSSI immediately before and 1 year after commencing agalsidase alfa ERT. Control data were obtained from 23 patients in whom AFD was excluded. The MSSI of patients with AFD was significantly higher than that of patients with other severe debilitating diseases. The MSSI indicated that, although more men than women had symptoms classified as severe, overall, the median total severity scores were not significantly different between male and female patients. One year of ERT with agalsidase alfa led, in all patients, to a significant (p < 0.001) reduction in MSSI score (by a median of nine points). This study has shown that the MSSI score may be a useful, specific measure for objectively assessing the severity of AFD and for monitoring ERT-related treatment effects.     

Proteinase-3 mRNA expressed by glomerular epithelial cells correlates with crescent formation in Wegener's granulomatosis

BACKGROUND: Wegener's granulomatosis (WG) is characterized by systemic vasculitis with crescentic glomerulonephritis (CGN) and circulating autoantibodies directed against neutrophil cytoplasmic antigens (ANCA). Proteinase 3 (PR-3), a neutral serine proteinase in neutrophils implicated in the growth control of myeloid cells, has been identified as the target antigen for ANCA in WG. Since the kidneys are frequently involved in WG, we studied the in situ expression of PR-3 by renal parenchymal cells. METHODS: We assessed the expression of PR-3 in kidney biopsies of 15 patients with WG by immunohistochemistry (IHC) and in situ hybridization (ISH). Normal kidney tissue served as the control. RESULTS: We detected PR-3 mRNA and PR-3 protein in distal tubular epithelial cells (TECs) and glomerular epithelial cells (GECs) in normal kidney tissue and in CGN. Furthermore, a strong glomerular PR-3mRNA expression restricted to the site of cellular crescents was detected in patients with WG. The analysis of 144 glomeruli with cellular or sclerotic crescents revealed a positive correlation of glomerular PR-3mRNA expression with the percentage of cellular crescents per glomerulus. The capability of human TECs and GECs to synthesize PR-3 was confirmed by Northern blot and ISH on cultured cells. CONCLUSION: These data provide evidence that nonhematopoetic renal parenchymal cells express PR-3 and that glomerular expression of PR-3 is associated with crescent formation in WG. Our findings suggest that renal parenchymal cells may directly be involved in the pathogenesis of CGN in WG.     

N-type calcium channel blockers - tools for modulation of cerebral functional units?

According to in vitro and in vivo studies, the direct application of N-type calcium channel blockers as for instance omega-conotoxin GVIA (omega-ctx) potently inhibits the release of neurotransmitters like dopamine. To find out whether this effect could be used for modulation of neurological functions, omega-ctx was used for continuous infusion into the functionally well characterized rat striatum. Over the 2-week time course of intrastriatal application, rats developed a decrease in spontaneous motor activity, spontaneous rotational asymmetry towards the side of application, and behavioral supersensitivity to apomorphine. After the end of infusion period, all functional deficits showed reversibility. The pattern of spontaneous neurological deficits - in particular supersensitivity to apomorphine - points to a substantial unilateral alteration of dopaminergic transmission due to omega-ctx, which is suggested also by an increase in dopamine receptor protein expression within the ipsilateral striatum. Time course and reversibility of neurological deficits caused by omega-ctx, as well as a lack of dopamine depletion contrast findings after selective destruction of dopaminergic neurons and support a functional modulation of dopaminergic transmission. The present study suggests that omega-ctx is an effective potent tool for the unilateral and reversible intracerebral modulation of neuronal circuits. Intracerebral application of omega-ctx could possibly open the way to therapeutic interventions.     

On the relationships between ultrasonic calling and anxiety-related behavior in rats

In the present review, the phenomenon of ultrasonic vocalization in rats will be outlined, including the three classes of vocalizations, namely 40-kHz calls of pups, and 22- and 50-kHz calls of juvenile and adult rats, their general relevance to behavioral neuroscience, and their special relevance to research on anxiety, fear, and defense mechanisms. Here, the emphasis will be placed on 40- and 22-kHz calls, since they are typical for various situations with aversive properties. Among other topics, we will discuss whether such behavioral signals can index a certain affective state, and how these signals can be used in social neuroscience, especially with respect to communication. Furthermore, we will address the phenomenon of inter-individual variability in ultrasonic calling and what we currently know about the mechanisms, which may determine such variability. Finally, we will address the current knowledge on the neural and pharmacological mechanisms underlying 22-kHz ultrasonic vocalization, which show a substantial overlap with mechanisms known from other research on fear and anxiety, such as those involving the periaqueductal gray or the amygdala.     

Environmental and Pharmacological Modulation of Amphetamine-Induced 50-kHz Ultrasonic Vocalizations in Rats

Rats emit high-frequency 50-kHz ultrasonic vocalizations (USV) in appetitive situations like social interactions. Drugs of abuse are probably the most potent non-social elicitors of 50-kHz USV, possibly reflecting their euphorigenic properties. Psychostimulants induce the strongest elevation in 50-kHz USV emission, particularly amphetamine (AMPH), either when applied systemically or locally into the nucleus accumbens (Nacc). Emission of AMPH-induced 50-kHz USV depends on test context, such as the presence of conspecifics, and can be manipulated pharmacologically by targeting major neurotransmitter systems, including dopamine (DA), noradrenaline (NA), and serotonin (5-HT), but also protein kinase C (PKC) signaling. Several D₁ and D₂ receptor antagonists, as well as typical and atypical antipsychotics block the AMPH-induced elevation in 50-kHz USV. Inhibiting D₁ and D₂ receptors in the Nacc abolishes AMPH-induced 50-kHz USV, indicating a key role for this brain area. NA neurotransmission also regulates AMPH-induced 50-kHz USV emission given that α₁ receptor antagonists and α₂ receptor agonists exert attenuating effects. Supporting the involvement of the 5-HT system, AMPH-induced 50-kHz USV are attenuated by 5-HT_2C receptor activation, whereas 5-HT_2C receptor antagonism leads to the opposite effect. Finally, treatment with lithium, tamoxifen, and myricitrin was all found to result in a complete abolishment of the AMPH-induced increase in 50-kHz USV, suggesting the involvement of PKC signaling. Neurotransmitter systems involved in AMPH-induced 50-kHz USV emission only partially overlap with other AMPH-induced behaviors like hyperlocomotion. The validity of AMPH-induced 50-kHz USV as a preclinical model for neuropsychiatric disorders is discussed, particularly with relevance to altered drive and mood seen in bipolar disorder.     

Letaler Verlauf eines Hitzeschocks nach körperlicher Anstrengung bei starker Sonneneinstrahlung

Heat stroke is a lifethreatening disease with high mortality, characterized by a body temperature of over 40°C and clinical symptoms of central nervous system dysfunction. However, the pathophysiological mechanisms are not fully understood. A new interesting explanation for the clinical symptoms could be a systemic inflammatory response due to barrier dysfunction in the intestine leading to endothelial damage and a syndrome of multiorgan dysfunction. We describe a 37-year-old male patient who collapsed while working in a vineyard in an environmental temperature of 32°C with a body temperature of 42.5°C. Despite intensive care treatment, he died with symptoms of shock and multiorgan dysfunction. Autopsy was performed followed by the histological evaluation of paraffin-embedded tissue. As correlates for clinical shock symptoms, shock kidneys and shock liver could be demonstrated. Furthermore, multiple microthrombi were found, together with clinically undetectable fibrinogen values. Finally, the patient died due to massive diffuse gastrointestinal bleeding and bleeding in pleural and pericardial cavities. No signs of severe edema of the central nervous system were detectable. This case supports the hypothesis that in heat stroke endothelial damage occurs with consecutive cascade of inflammatory and coagulatory reactions, which may play a critical pathophysiological role.