A NOVEL BIOLOGICAL DOSIMETRY ASSAY AS A POTENTIAL TOOL FOR TRIAGE DOSE ASSESSMENT IN CASE OF LARGE-SCALE RADIOLOGICAL EMERGENCY

In case of mass radiological emergencies, new strategies involving biological and clinical endpoints are requested for an efficient triage classification of casualties. For this purpose, we developed a novel protocol combining the two most established cytogenetic methods used in biological dosimetry (dicentric and micronucleus assays) into a single one, in order to have a time-saving, inexpensive and potentially automatable instrument to be used for triage purposes in case of large-scale radiological events. This method could be considered as a 'three in one' assay allowing the simultaneous scoring of chromosome aberrations and micronuclei on a single slide, and also enabling to discriminate between metaphases in first and second cell division without the Fluorescence plus Giemsa staining. This method needs further validation through inter-comparisons involving biological dosimetry laboratories, to verify its reproducibility. Moreover, the possibility to apply the already existing software for automation for dicentric and micronucleus assays could be also verified.

Motherhood – a disturbed beginning: A review of a case series

Introduction

Perinatal mental illness is one of the most frequent complications of pregnancy and the postpartum period. During the puerperium, the risk of developing a mental disease, such as a psychotic episode, is higher than in any other time in a woman's life.

Objectives

The two main objectives are to describe a case series of 4 patients diagnosed with pospartum psychosis, and to synthesize the most important facets of this mental illness based on a literature review.

Aims

The aim is to provide an overview of the clinical and epidemiological aspects of postpartum psychosis.

Methods

The four clinical cases are presented by describing the similar as opposed to the differential aspects between all patients, using the information obtained through successive clinical interviews and the case file. Research was accomplished through Clinical Key and PubMed (2005-2015) using the keywords: postpartum psychosis.

Results

In all four cases, the patients developed symptoms of sleep disturbance, mood fluctuation, altered thinking process with delusions or obsessions, and bizarre behaviours. This occurred within the first four weeks after labour, which was in all cases an obstrutced labour. The data suggests that postpartum psychosis is a presentation of bipolar disorder. Clinical aspects and risk factors related to this perinatal complication all coincide with the cases presented.

Conclusions

Postpartum psychosis is a rare presentation of perinatal mental illness. However, it presents itself, as a psychiatric emergency, and the early and correct assessment are crucial to reset the development of the mother–child bond.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Non-motor symptoms and cardiac innervation in SYNJ1-related parkinsonism

INTRODUCTION

PARK20 is a rare autosomal recessive parkinsonism related to the SYNJ1 gene and characterized by early-onset of disease and atypical signs such as supranuclear vertical gaze palsy, dementia, dystonia, and generalized tonic-clonic seizures.

OBJECTIVE

Non-motor features and cardiac sympathetic innervation were assessed in two siblings affected by parkinsonism who harboured the homozygous Arg258Gln mutation in the SYNJ1 gene.

METHODS

The Non-Motor Symptoms, the SCOPA-AUT, the Mayo Sleep Questionnaires and polysomnography were used to investigate non-motor signs (NMS), autonomic dysfunction and REM Behavioural Disorder (RBD). Cognitive functions were examined by an extensive battery of neuropsychological tests. In addition, motor and sensory nerve conduction studies and evoked laser potentials were performed. Cardiac sympathetic innervation was assessed in the two patients by (123)I-metaiodobenzylguanidine (MIBG) scintigraphy, computing early and late heart-to-mediastinum (H/M) ratios and myocardial washout rates (WR).

RESULTS

Among the non-motor symptoms and autonomic signs, case 1 had cold intolerance, drooling and dysphagia, while case 2 had pain and urinary dysfunction. Both cases showed mood and behavioural disorders. RBD were not found, whereas the neuropsychological assessment revealed a progressive cognitive impairment. Neurophysiological studies revealed no abnormalities. Indexes of cardiac sympathetic innervation in the two patients did not differ from those of control subjects.

CONCLUSIONS

Our findings expand the phenotypic profile of SYNJ1-related parkinsonism. Preserved cardiac sympathetic function and absence of RBD suggest that PARK20 should be explained by a pathogenic mechanism different from Lewy Body pathology, or that the latter is not as widespread as idiopathic Parkinson's disease.

Sonic hedgehog stimulates proliferation of human periodontal ligament stem cells

Regulation of cell renewal in the periodontium is a critical cell function that has not been clarified. Sonic hedgehog (Shh) is a secreted signaling molecule that plays a key role during development and adult tissue homeostasis. In the present study, we have analyzed the role played by Shh in human periodontal ligament stem cell (HPLSC) proliferation. HPLSC were isolated with anti-STRO-1 antibodies. Shh increased the expression of GLI1 and PTC-1 and selectively stimulated cell proliferation in STRO-1(+) derived from adult periodontal ligament. Shh components were localized to primary cilia in STRO-1(+) cells after Shh stimulation. STRO-1(+) also expressed Shh, suggesting an autocrine-regulated phenomenon. Thus, we propose that Shh plays a critical role in the regulation of cell proliferation in STRO-1(+)/HPLSC.

Impact of malolactic fermentation on low molecular weight phenolic compounds

A reversed phase liquid chromatography-DAD method is proposed for analysis of major non-flavonoid phenolic compounds in wines. The method employed a mixture of acetic acid, water and methanol as eluents and was used to evaluate the impact of malolactic fermentation in low molecular phenolic compounds. The wines analyzed underwent different treatments, like the addition of a pectolytic enzyme or lysozyme, and the way malolactic fermentation was carried out-spontaneously or with the inoculation of two different commercial lactic bacteria. The main result observed was the disappearance of hydroxycinnamoyltartaric acids and the increase of resultant free forms, regardless the way malolactic fermentation was carried out.

The Sonic Hedgehog-Gli pathway regulates dorsal brain growth and tumorigenesis

The mechanisms that regulate the growth of the brain remain unclear. We show that Sonic hedgehog (Shh) is expressed in a layer-specific manner in the perinatal mouse neocortex and tectum, whereas the Gli genes, which are targets and mediators of SHH signaling, are expressed in proliferative zones. In vitro and in vivo assays show that SHH is a mitogen for neocortical and tectal precursors and that it modulates cell proliferation in the dorsal brain. Together with its role in the cerebellum, our findings indicate that SHH signaling unexpectedly controls the development of the three major dorsal brain structures. We also show that a variety of primary human brain tumors and tumor lines consistently express the GLI genes and that cyclopamine, a SHH signaling inhibitor, inhibits the proliferation of tumor cells. Using the in vivo tadpole assay system, we further show that misexpression of GLI1 induces CNS hyperproliferation that depends on the activation of endogenous Gli1 function. SHH-GLI signaling thus modulates normal dorsal brain growth by controlling precursor proliferation, an evolutionarily important and plastic process that is deregulated in brain tumors.

Calcium mediates dorsoventral patterning of mesoderm in Xenopus

Calcium signals participate in the differentiation of electrically excitable and nonexcitable cells; one example of this differentiation is the acquisition of mature neuronal phenotypes. For example, transient elevations of the intracellular calcium concentration have been recorded in the ectoderm of early embryos, and this elevation has been proposed to participate in neural induction. Here, we present molecular evidence indicating that voltage-sensitive calcium channels (VSCC) are involved in early developmental processes leading to the establishment of the dorsoventral (D-V) patterning of a vertebrate embryo. We report that alpha1S VSCC are expressed selectively in the dorsal marginal zone at the early gastrula stage. The expression of the VSCC correlates with elevated intracellular calcium levels, as evaluated by the fluorescence of the intracellular calcium indicator Fluo-3. Misexpression of VSCC leads to a strong dorsalization of the ventral marginal zone and induction of the secondary axis but no direct neuralization of the ectoderm. Moreover, specific inhibition of VSCC by the use of calcicludine results in ventralization of the dorsal mesoderm. Together, these results indicate that calcium channels regulate mesodermal patterning by specificating the D-V identity of the mesodermal cells. The D-V patterning of the mesoderm has been shown to depend on a gradient of BMPs activity. We discuss the possibility that VSCC affect or act downstream of BMPs activity.

Fluoro derivatives of bis(salicylideneaminato-N,O)copper(II) and -oxovanadium(IV)

The structures of five complexes of fluorine-containing bidentate salicylideneamine Schiff base ligands are reported. These are the bis-ligand copper(II) complexes of the Schiff bases derived from salicylaldehyde and 4-fluoro-, [Cu(C(13)H(9)FNO)(2)], 3-fluoro-4-methyl-, [Cu(C(14)H(11)FNO)(2)], 3,5-bis(trifluoromethyl)-, [Cu(C(15)H(8)F(6)NO)(2)], and 4-trifluoromethoxyanilines, [Cu(C(14)H(9)F(3)NO(2))(2)], and the bis-ligand oxovanadium(IV) complex of the Schiff base derived from salicylaldehyde and 4-trifluoromethoxyaniline, [VO(C(14)H(9)F(3)NO(2))(2)]. Three of the copper complexes have square-planar coordination at the metal, imposed by the virtue of symmetry, but the immediate coordination environment of the copper in the 3,5-bis(trifluoromethyl) complex is intermediate between square planar and tetrahedral. The coordination environment at the metal of the vanadium complex can be described as distorted square pyramidal.

Hyperkalemic periodic paralysis M1592V mutation modifies activation in human skeletal muscle Na+ channel

Mutations in the human skeletal muscle Na+ channel underlie the autosomal dominant disease hyperkalemic periodic paralysis (HPP). Muscle fibers from affected individuals exhibit sustained Na+ currents thought to depolarize the sarcolemma and thus inactivate normal Na+ channels. We expressed human wild-type or M1592V mutant alpha-subunits with the beta1-subunit in Xenopus laevis oocytes and recorded Na+ currents using two-electrode and cut-open oocyte voltage-clamp techniques. The most prominent functional difference between M1592V mutant and wild-type channels is a 5- to 10-mV shift in the hyperpolarized direction of the steady-state activation curve. The shift in the activation curve for the mutant results in a larger overlap with the inactivation curve than that observed for wild-type channels. Accordingly, the current through M1592V channels displays a larger noninactivating component than does that through wild-type channels at membrane potentials near -40 mV. The functional properties of the M1592V mutant resemble those of the previously characterized HPP T704M mutant. Both clinically similar phenotypes arise from mutations located at a distance from the putative voltage sensor of the channel.

Brainstem involvement in obsessive-compulsive disorder

We investigated the possible involvement of the brainstem in the pathology of obsessive-compulsive disorder. Brainstem auditory evoked potentials (BAEPs) were collected from a population of neurotics (100 patients), including a group of 50 subjects suffering from obsessive-compulsive disorder (OCD) and the rest having generalized anxiety disorder. Twenty-five, age- and sex-matched, healthy volunteers served as controls. BAEPs were recorded by standard techniques as recommended by the AEEGS Clinical Evoked Potentials Guidelines. A one-way analysis of variance and the Fisher least-significant difference test were used for statistical analysis of the data. After stimulation of the right ear, a significant increase of wave I-V interpeak latency was found in the two groups of patients as compared with that of controls. Moreover OCD patients had a significantly reduced amplitude of wave III when compared to that of the control group. Our electrophysiological data suggest a possible involvement of brainstem in OCD pathogenesis. We discuss our findings in relation to biochemical, anatomical and physiological alterations described in the literature for serotonin-dependent systems.

Sperm interaction with human oviductal cells in vitro

In this article we describe the in-vitro interaction between human spermatozoa and oviductal epithelial cell monolayers. Freshly obtained spermatozoa were added to culture dishes containing human oviductal cells (co-culture), culture medium (control) or culture medium which had previously been used for culture of oviductal cells (conditioned medium). At 0, 5, 24, and 48 h of incubation the percentage of motile spermatozoa was determined and their motion characteristics analysed. Aliquots were taken to determine the percentage of acrosome-reacted spermatozoa. The spermatozoa were motile for a longer period in the presence of oviductal cells (54 +/- 9% co-culture versus 18 +/- 3% control, at 48 h) and the kinetics of the acrosome reaction exhibited a different pattern. In the control the percentage of reacted spermatozoa increased progressively throughout incubation. In co-culture, there was an increase only at 5 h; thereafter, the percentage of acrosome reactions did not change. Spermatozoa incubated in conditioned medium exhibited a behaviour halfway between the control and the co-culture. The pattern of sperm movement was not different in any of the experimental conditions. Although there was no binding between spermatozoa and oviductal epithelial cells, the frequency of the ciliary beat increased after spermatozoa were added to the oviductal cell monolayers. These results suggest that incubation with oviductal cells increases sperm survival, stabilizes the acrosome, and modifies the frequency of ciliary beat.

An electrophysiological study in obsessional compulsive disorders

Recent anatomoclinical and neuroimaging studies have suggested a possible relation between obsessional compulsive disorders (OCD) and some brain damage, such as frontolenticular lesions, basal ganglia cavitations and local glucose metabolism impairment. A poor frontocaudal regulation of the left hemisphere and an autonomic nervous system dysfunction in OCD patients have been supposed. To absess these morphofunctional abnormalities, an electrophysiological approach has been performed in 100 consecutive neurotic patients, screened with various neuropsychological tests and divided in two groups, 50 with OCD and 50 with anxious neurosis (ANX). Patients were submitted to EEG spectral analysis and BAEP studies and comparated with 25 age-matched normal controls. The mean alpha power in occipital regions was significantly higher in OCD patients and reduced in ANX patients. A significant reduction of the beta activity was recorded in frontal regions in both patient groups as compared to controls. A slight (p < 0.11) increase in I-V interpeak latency (IPL) vs. control group was observed in BAEP from left ear. A significant increase of the same IPL in OCD vs. controls (p < 0.025) was observed in BAEP from right ear. A slight n.s. reduction in III wave amplitude in OCD patients was observed in BAEP from left ear, whereas a highly significant reduction in the same wave amplitude from BAEP from right ear was observed in OCD patients. The above findings cold be account for both a frontotemporal and brainstem dysfunction with a probable involvement of serotoninergic central pathways, with a significant impairment of pontine segment in ANX patients and of mesencephalic region in OCD patients.

S.P.E.C.T., E.E.G. and M.R.I. investigations in complex partial epilepsy

We present SPECT, electroencephalography (EEG) and magnetic resonance imaging (MRI) data of a homogeneous group of 12 young adults with rare focal seizures and a good response to carbamazepine. Our data suggest that the alterations of the rCBF are independent of severity and duration of the epilepsy and of the frequency of seizures. Based on our experimental data, it may be suggested that complex partial epilepsy is a good biological model to investigate the neurogenic control of cerebral flow and metabolism.

Somatosensory evoked potentials in non-insulin-dependent diabetics with different degrees of neuropathy

Changes in median nerve somatosensory evoked potential (SEP) in diabetic patients have amply been reported. However the relationships between the diabetic polyneuropathy and the abnormalities of SEPs are still a matter of discussion. To elucidate these relationships, we have studied SEPs in 38 non-insulin-dependent diabetics with mild or severe degree of peripheral neuropathy. Our principal findings are as follows. (i) The wrist-Erb point (EP) conduction velocity (WECV) and the EP-N13 interpeak latency are significantly altered in diabetics. The N11-N13, N13-N20 and N13-P22, interpeak latencies are within the normal range. (ii) The WECV is more reduced in patients with severe neuropathy than in those with mild neuropathy, whereas the degrees of neuropathy have no influence on the alterations of EP-N13 interpeak latency. (iii) No significant correlation is found between the WECV and the EP-N13 interpeak latency. (iv) The WE conduction velocity was significantly correlated with both motor and sensory peripheral nerve conduction velocities. On the contrary, no correlation is found between these latter peripheral parameters and the EP-N13 interpeak latency. These findings indicate that the alteration in the tract from brachial plexus to the posterior column could not be a parallel process of distal neuropathy of non-insulin-dependent diabetic patients.

Correlation between neuroradiological and electrophysiological investigations in multiple sclerosis with features of a cerebral tumour

Multiple sclerosis presenting at onset with clinical signs and CT picture suggesting a cerebral neoplasm or a slowly evolving stroke, is uncommon. We report one patient in whom cerebral tumour was suspected not only clinically but also from CT features. M.R.I., demonstrating multifocal, high intensity, unsuspected periventricular and white-matter lesions, permitted to diagnose what seemed an intracranial left parietal neoplasm as an acute plaque of demyelination. In fact, in the follow-up, this large low-intensity left parietal area acquired structural and volumetrical homogeneity compared to all other present hyperintense lesions. Instead multimodal EPs, though disclosing subclinical dysfunction in the early stage of the disease, did not correlate with changes in neurological examination to follow-up. So they, unlike the M.R.I., seem of no particular usefulness to serially monitor the clinical modification of MS.

Hindbrain hernia headache and syncope in type I Arnold-Chiari malformation

We describe two young women affected with syncopal episodes and occipital headache exacerbated by cough, sneezing, rising, or effort. MRI revealed in both patients type I Arnold-Chiari malformation. A craniospinal pressure dissociation with brainstem compression may be involved in the pathogenesis of headache and syncope.

Methods for the analysis of cellular kinetics in PHA-stimulated blood lymphocytes using BrdU incorporation. A comparative study

The cellular cycle (cc) span was measured by using differential sister-chromatid staining (DSCS) and applying the following methods: cellular cycle time (cct) according to the graphic method of Dutrillaux and Fosse (G-cct); the analytical equation (A-cct) proposed in the present paper, and the average generation time (AGT) suggested by Ivett and Tice. The mean values obtained by the three methods were 12.5, 12.7, and 19.5 h, respectively. A-cct is the more precise method, since the equation of the analytical procedure allows the utilization of numerical data, and when the graphical method is used, the values plotted in a graph may vary according to the employed scale. Cct is the choice over AGT because the first evaluates actively dividing cells and only considers those at M2 or M3. It will be useful to study cell proliferation kinetics in genetic pathological conditions and to investigate with accuracy the effect of cytostatic and cytotoxic drugs.

Multimodality evoked potentials in sporadic amyotrophic lateral sclerosis: a statistical approach

The involvement of sensory pathways in patients suffering from amyotrophic lateral sclerosis (ALS) is well reported in histopathological studies. Several laboratories have also used evoked potentials to evidentiate subtle dysfunctions of sensory systems in such patients. However, conflicting results have been presented in studies using evoked potentials. In the present experiment we have evaluated multimodality evoked potentials in subjects with sure diagnosis of sporadic ALS, by means of the Bonferroni multiple comparisons procedure. Our principal findings are: a) no statistical difference between patients and controls in BAEP and VEP recordings; b) a reduction of N13 amplitude and a prolonged P22 latency in SEP recordings. Due to the sources of N13 and P22, these latter alterations, however, do not implicate the involvement of somatosensory pathway. In conclusion, the current investigation does not provide an electrophysiological support for the involvement of sensory systems in the sporadic ALS.

Antiphospholipid antibodies in young adults with cerebrovascular ischemic disease

In this survey we reviewed some of the most recent laboratory and clinical studies on cerebral ischemia in young patients with antiphospholipid antibodies (aPLs). A strong association between aPLs and cerebrovascular ischemic disease has been documented, but the underlying pathogenetic mechanism remains unclear. Furthermore, long-term prognosis is not clear since too few controlled longitudinal studies had been reported. Further prospective clinical trials are needed to define risk factors, to identify different subgroups of patients, and to lead to an effective therapy.

Evoked potentials in brain death. A critical review

The development of transplant surgery has determined the necessity to revise criteria and to apply new electrophysiologic techniques to add further informations when survival of brain function is in question. The EPs, which provide a sensitive tool for assessment of integrity of main sensorial systems, could have a place in the electrophysiologic evaluation of the brain death. This review deals with the role of EPs in brain death and points out the main patterns found in that clinical condition.

Sneddon's syndrome, anticardiolipin antibodies and anticardiolipin cofactor. A case report

Sneddon's syndrome is a rare entity characterized by idiopathic livedo reticularis and cerebrovascular lesions. A case of a young woman with livedo reticularis and progressive cerebral arteriopathy is described. Abnormalities of sexual and gonadotropic hormones were present. Anticardiolipin and anticardiolipin-cofactor complex antibodies were not found.

Dopaminergic regulation of epileptic activity

We evaluated the role of dopamine systems in the propagation of epileptic Focal, limbic seizures were produced by systemically administered pilocarpine (200 mg/kg, i.p.); as previously described this dose produces limbic stereotypes but neither convulsions nor seizure-related brain damage. The systemic pretreatment with D-1, but not D-2, agonists induced convulsions identical to those produced by a higher, convulsant dose of pilocarpine (400 mg/kg). Conversely, the pretreatment with D-1 receptor antagonists prevented the convulsions whereas the D-2 antagonists facilitated the pilocarpine-induced seizures. Furthermore, we studied the effects of intracerebral injections of dopamine agents on seizures induced by pilocarpine. Nigral microinjection of D-1 agonists strongly induced motor seizures in rats treated with the low dose of pilocarpine. On the other hand, microinjection of D-1 antagonists prevented the motor seizures induced by the high dose of pilocarpine. This study indicates that the two dopamine receptor subtypes, D-1 and D-2, exert opposing roles in the control of epilepsy propagation. Substantia nigra pars reticulata appears to be primarily involved in the dopamine-mediated modulation of seizures.

Spinal cord injury: some epidemiological data. A review of 233 cases

Two hundred thirty-three consecutive cases of traumatic para- and tetraplegia admitted to a department of Neurosurgery in Naples within ten years were reviewed and categorized according to etiology, level of lesion and clinical features. The age of the patients at the time of injury varied from 7 to 74 years with a mean age of 37.1 +/- 17.1 (male mean age = 35.8 +/- 16.7; female mean age = 41.5 +/- 18.2). The male/female sex ratio was 4.8. Of these patients 66 were paraplegic and 167 were tetraplegic. The analysis of the various causes of the spinal cord injury showed that the occupational activities take the first place (32.2%); injuries in recreational activities and road accidents accounted for the majority of the remaining cases.

Evoked potentials in shoe-workers with minimal polyneuropathy

The aim of the present research was to investigate early impairments of central nervous system in subjects exposed to a low toxic level of industrial solvents for several years. Therefore a group of fifteen shoe-workers, with symptoms of minimal polyneuropathy, and a group of twenty, sex and age matched, healthy volunteers were selected for multimodal evoked potentials studies. The statistical analysis revealed a decrease of VEP and SEP amplitudes as well as a significant higher percentage of cases with BAEP V/I ratio between 0.5 and 1 among patients. The wrist-Erb's point conduction velocity was, also, found lowered in them. In accordance with the experimental results, the systematic employment of multimodal evoked potentials is proposed for screening the subjects exposed to neurotoxic influence of industrial solvents.

Dopamine D1 and D2 receptors mediate opposite functions in seizures induced by lithium-pilocarpine

The effect of selective dopamine receptor blockade on epileptic activity was tested in rats, using the lithium-pilocarpine seizure model. One day after lithium pretreatment, systemic administration of the dopamine D1 antagonist, SCH 23390, prevented the convulsive activity induced by either 10 or 15 mg/kg of pilocarpine in a dose-dependent manner as revealed by behavioral and electroencephalographic alterations. No anticonvulsant effect was observed when SCH 23390 was injected at the same time as lithium and 24 h prior to pilocarpine. Furthermore, the D2 antagonists, raclopride and haloperidol, potently reduced the threshold for convulsions induced by 10 mg/kg of pilocarpine, following lithium pretreatment. Neither dopamine D1 nor D2 antagonists altered the limbic stereotypies induced by pilocarpine, supporting the view that the dopamine system is primarily involved in the mechanisms of convulsion generation and seizure spreading. These results indicate that dopamine receptor subtypes exert opposite functions on the regulation of convulsive activity.

Electrophysiological monitoring of neural functions during neurosurgery

The intraoperative evoked potential monitoring has become indispensable in patients at risk for neurologic damages during surgery. This review presents the principal clinical indications for intraoperative monitoring of sensory and motor functions of spinal cord as well as of the auditory, facial and optic nerves and of brain functions during cerebrovascular surgery.

Clinical applications of evoked potentials in neurological disorders

The functional integrity of the main sensorial systems and of the central motor pathways can be evaluated through multimodal evoked potentials and non-invasive transcranial stimulation of the motor cortex. In this review the authors summarize the main clinical indications of the afore said methods specifically in the field of the neurological disorders.

Dopamine D1 receptor modulation of pilocarpine-induced convulsions

The contribution of dopaminergic mechanisms to the generalization of epileptic activity was studied in rats given pilocarpine after pretreatment with selective dopamine agonists. At the dose of 200 mg/kg, pilocarpine produced limbic stereotypes but not convulsions or seizure-related brain damage. Pilocarpine, 200 mg/kg, following pretreatment with the D1 agonist (RS)-2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3 benzazepine, but not its (S)-enantiomer, induced convulsive activity as revealed by behavioral, electroencephalographic alterations and widespread brain damage. These features were identical to those produced by a higher, convulsant dose of pilocarpine (400 mg/kg). On the other hand, pretreatment with the D2 agonist 4,4a,5,6,7,8,8a,9-octahydro-5-n-propyl-2H-pyrazolo-3,4-g-quinoline failed to induce convulsions. Furthermore, the D1 receptor antagonist (R)-(+)-8-chloro-2,3,4,5-n-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine -7-ol prevented the convulsive activity induced by both 2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3 benzazepine plus pilocarpine (200 mg/kg) and pilocarpine (400 mg/kg), given alone. However, neither dopamine agonists nor antagonists altered the limbic stereotypes induced by pilocarpine, suggesting a dopamine system involvement primarily in the mechanisms of epilepsy generalization. The results suggest that pharmacological manipulation of dopaminergic transmission may provide an alternative approach to therapy of secondarily generalized epilepsy.

Electroretinographic findings in inherited ataxias

Electroretinogram was performed in 18 patients with inherited ataxias. Eight had Friedreich's disease, 9 autosomal dominant cerebellar ataxia and one early onset cerebellar ataxia with retained tendon reflexes. Abnormalities were found in one patient for each group. The most frequent were decreased b-wave amplitude in photopic and scotopic conditions and prolonged implicit time.

Agenesis of the cerebellar vermis: otoneurological report in one patient

We have performed otoneurological examination in a case of vermis cerebelli agenesia, CT scan confirmed. Visuo-vestibular interaction (VST) abnormality, with normal saccades and normal smooth pursuit movements, allows to suppose normal functioning of the flocculus and a damage in the nucleus olivaris inferior and, particular, in the paraolive.

D-1 dopamine agonist administration reduces the threshold for convulsions produced by pilocarpine

Focal, limbic seizures were produced by systemically administered pilocarpine (200 mg/kg, i.p.); as previously described this dose produces limbic stereotypies but neither convulsions nor seizure-related brain damage. The pretreatment, 5 minutes prior pilocarpine, with the D-1 agonist SKF 38393 (-ED50 = 1 mg/kg; i.p.) induced convulsions similar to those produced by a higher, convulsant dose of pilocarpine. On the other hand, the pretreatment with the D-2 agonist LY 171555 failed to induce convulsions. The D-1 receptor antagonist SCH 23390 prevented the convulsions induced by SKF 38393 plus pilocarpine (200 mg/kg). This study indicates that D-1, but not D-2, receptor stimulation converts subconvulsant doses of pilocarpine into convulsant ones.

Chromosome abnormalities and sister chromatid exchanges in children with acute intoxication due to inhalation of volatile substances

Deliberate inhalation of volatile substances is a common and harmful practice among young persons worldwide. Recently, we described chromosome damage in children who chronically inhale volatile agents. Clinical and cytogenetic studies were performed for 15 "sniffing" children (13 boys and 2 girls), the purpose of which was to define the chromosomal effect of the acute intoxication. A significant increase in the rate of chromosome abnormalities and in the frequency of sister chromatid exchanges (SCEs) was found in sniffers vs. controls. The values were also higher in children who were acutely intoxicated than in those who chronically inhaled volatile agents. Clinical, socioeconomic, and cytogenetic findings are also discussed.