Silicon as an attenuator of the toxic effects of aluminum in Schinus terebinthifolius plants.

Aluminum (Al) is highly toxic to plants, since it causes stress and inhibits plant growth. Silicon (Si) is known to mitigate the stress caused by Al in several plant species. Thus, the current study aims to investigate the soothing effects of Si on morphophysiological and photosynthetic variables, and the attributes associated with oxidative stress in Schinus terebinthifolius plants exposed to Al. Treatments have followed a completely randomized design, with three repetitions based on the following Al/Si combinations (in mM): Treatment 1: 0 Al + 0 Si; Treatment 2: 0 Al + 2.5 Si; Treatment 3: 1.85 Al + 0 Si; Treatment 4: 1.85 Al + 2.5 Si; Treatment 5: 3.71 Al + 0 Si; Treatment 6: 3.71 Al + 2.5 Si. Each sampling unit consisted of a tray with 15 plants, totaling forty-five per treatment. Shoot and root morphological variables, photosynthetic variables, photosynthetic pigments, hydrogen peroxide concentration, lipid peroxidation (MDA), guaiacol peroxidase (POD) and superoxide dismutase (SOD) enzymes, and non-enzymatic antioxidant such as Ascorbic acid (AsA) and non-protein thiol (NPSH) concentration were assessed. Root growth inhibition followed by changes in root morphological variables have negatively affected root and shoot biomass production in plants only subjected to Al. However, adding 2.5 mM Si to the treatment has mitigated the toxic effects caused by 1.85 mM of aluminum on S. terebinthifolius plants.

Silicon as an attenuator of the toxic effects of aluminum in Schinus terebinthifolius plants / Silício como atenuador dos efeitos tóxicos do alumínio em plantas de Schinus terebinthifolius

Aluminum (Al) is highly toxic to plants, since it causes stress and inhibits plant growth. Silicon (Si) is known to mitigate the stress caused by Al in several plant species. Thus, the current study aims to investigate the soothing effects of Si on morphophysiological and photosynthetic variables, and the attributes associated with oxidative stress in Schinus terebinthifolius plants exposed to Al. Treatments have followed a completely randomized design, with three repetitions based on the following Al/Si combinations (in mM): Treatment 1: 0 Al + 0 Si; Treatment 2: 0 Al + 2.5 Si; Treatment 3: 1.85 Al + 0 Si; Treatment 4: 1.85 Al + 2.5 Si; Treatment 5: 3.71 Al + 0 Si; Treatment 6: 3.71 Al + 2.5 Si. Each sampling unit consisted of a tray with 15 plants, totaling forty-five per treatment. Shoot and root morphological variables, photosynthetic variables, photosynthetic pigments, hydrogen peroxide concentration, lipid peroxidation (MDA), guaiacol peroxidase (POD) and superoxide dismutase (SOD) enzymes, and non-enzymatic antioxidant such as Ascorbic acid (AsA) and non-protein thiol (NPSH) concentration were assessed. Root growth inhibition followed by changes in root morphological variables have negatively affected root and shoot biomass production in plants only subjected to Al. However, adding 2.5 mM Si to the treatment has mitigated the toxic effects caused by 1.85 mM of aluminum on S. terebinthifolius plants.

O alumínio (Al) é altamente tóxico para as plantas, pois causa estresse e inibe o crescimento vegetal. O silício (Si) é conhecido por atenuar o estresse causado pelo Al em diversas espécies vegetais. Assim, o presente estudo tem como objetivo investigar os efeitos suavizantes do Si sobre variáveis morfofisiológicas e fotossintéticas, e os atributos associados ao estresse oxidativo em plantas de Schinus terebinthifolius expostas ao Al. Os tratamentos seguiram um delineamento inteiramente casualizado, com três repetições baseadas nas seguintes combinações Al/Si (em mM): Tratamento 1: 0 Al + 0 Si; Tratamento 2: 0 Al + 2,5 Si; Tratamento 3: 1,85 Al + 0 Si; Tratamento 4: 1,85 Al + 2,5 Si; Tratamento 5: 3,71 Al + 0 Si; Tratamento 6: 3,71 Al + 2,5 Si. Cada unidade amostral constou de uma bandeja com 15 plantas, totalizando quarenta e cinco plantas por tratamento. Variáveis morfológicas da parte aérea e da raiz, variáveis fotossintéticas, pigmentos fotossintéticos, concentração de peróxido de hidrogênio, peroxidação lipídica (MDA), enzimas guaiacol peroxidase (POD) e superóxido dismutase (SOD) e antioxidantes não enzimáticos como ácido ascórbico (AsA) e grupos tiós não protéicos (NPSH) foram avaliadas. A inibição do crescimento radicular seguida de alterações nas variáveis morfológicas radiculares afetaram negativamente a produção de biomassa radicular e aérea em plantas submetidas apenas ao Al. No entanto, a adição de 2,5 mM de Si ao tratamento atenuou os efeitos tóxicos causados por 1,85 mM de alumínio em plantas de S. terebinthifolius.

[Tic disease. Current genetic and neurochemical factors]. / Doença dos tiques. Aspectos genéticos e neuroquímicos atuais.

We review historical, conceptual, clinical and diagnostic criteria as well as present genetic and neurochemical factors of tic disorders. Epidemiologic data suggest that tic is an organic disease with autosomal dominant transmission. We emphasize immunohistochemical studies particularly related to the dopaminergic, noradrenergic and serotonergic systems. These modulate the activity of the cortico-striato-thalamocortical circuits implicated in both Tourette's syndrome and obsessive-compulsive disorder.

[New dopaminergic agonists]. / Novos agonistas dopaminérgicos.

We present a brief review of the literature about dopaminergic agonists. We report the five known dopaminergic receptors, where they are located, the advantages and disadvantages of the employment in parkinsonian patients. The dopaminergic agonists were introduced to control the limitations of levodopa-increasing the therapeutic window. We analyse the pharmacocynetic efficacy and the side effects of cabergoline, ropinirole and pramipexole.

Possible involvement of nitric oxide in pilocarpine induced seminal emission in rats.

Intraperitoneal injection of pilocarpine (0.75-3.0 mg/kg) caused a dose-related seminal emission in adult male rats. The seminal emission response to 3 mg/kg of pilocarpine was greatly reduced in atropinized (5 and 10 mg/kg, SC) animals, suggesting a cholinomimetic effect. Nw-nitro-L-arginine methyl ester (5, 10, and 20 mg/kg, SC), a nitric oxide synthesis inhibitor, also inhibited the pilocarpine-induced seminal emission, which was reversed by L-arginine (600 mg/kg, SC) or by coinjection of sodium nitroprusside (0.5 mg/kg, SC). Urine analysis for levels of nitric oxide metabolites, nitrate/nitrite (NO3-/NO2-), showed marked alterations in accordance with the drug treatments. The results suggest that nitric oxide mediates the inhibitory neurotransmission responsible for seminal emission in pilocarpine stimulated rats.

[Differential diagnosis of tremors]. / Diagnóstico diferencial dos tremores.

After the review of the literature the author presents the semiologic basis for the differential diagnosis of rest and action tremors. The parkinsonian, severe essential, rubral, tardive, postural, kinetic and the task or position-specific tremors are mainly analysed.

[Dementia in Parkinson's disease. Critical evaluation of the literature]. / Demência na doença de Parkinson. Avaliação crítica da literatura.

In the last 30 years, Parkinson's disease has been object of great progress. The majority of patients reaches a longer life with quality because of the modern therapeutic approach. However, dementia that can occur in the evolutive process, has its neuropathology not completely defined until now. There are lesions in the basal ganglia, in the ventral area of the mesencephalic tegmentum in the thalamus, in the substantia nigra and in the frontal cortex. The presence of Lewy bodies in the cortex is associated with dementia, in the same way that the anatomopathological features of Alzheimer's disease, in many cases. Dementia should have a multifactorial basis. Different types of neurotransmitters, like serotonin, acetylcholine and dopamine, or even hormones, like cortisol, may be altered in a great number of demented parkinsonians. Depression, found in up to 40% of patients, have been related as a risk factor for dementia, present approximately in 25% of cases. Studies in this area are still conflicting, with some confirming the relation among depression, cortical atrophy, hypercortisolemia and Parkinson's disease. Neuropsychologic studies show that the dementia in Parkinson's disease is of subcortical type. It is also known that parkinsonians, even those without cognitive deficiencies clinically significant, present deficits if submitted to more detailed neuropsychological tests. It is assumed, so, that cognitive impairments are intrinsic to the disease, varying its expression among patients. Dementia shall be diagnosed based on the criteria established in the diagnostic and statistical manual of mental disorders of the American Psychiatry Association, as well as computed tomography and magnetic resonance. For treatment, parkinsonian dementia does not recognize efficacious agents until now.

[Dystonias: clinical and therapeutic aspects in 64 patients]. / Distonias. Aspectos clínicos e terapêuticos em 64 pacientes.

The experience with 64 patients with dystonia seen at the Extrapyramidal Diseases Sector of the Neurology Department of the Hospital Universitário Clementino Fraga Filho of the UFRJ is presented as well as the pertinent review of the literature. The five-and-a-half-year of follow-up showed that 33 were male and 31 female; 48 were white, 10 mulatto and 6 negro; the mean time of disease was 9 years and 8 months. According to the distribution of the movement disorder, 30 (46.9%) were focal, 17 (26.6%) segmental, 13 (20.3%) generalized, 3 (4.7%) hemidystonia and 1 (1.5%) multifocal. In 11 (17.2%) the age of onset was before 12 years old, in 6 (9.4%) between 13 and 20 years old, and in 47 (73.4%) after 20 years old. According to the etiology, 39 (60.9%) were idiopathic sporadic, 6 (9.4%) were idiopathic familial and 19 (29.7%) were symptomatic. The therapeutical approach used in these patients were anticholinergic drugs, dopaminergic agonists or antagonists and baclofen, alone or associated with anticholinergic drugs for generalized dystonia. The authors conclude that botulinum toxin type A is the most valuable therapeutic agent in the treatment of focal dystonia.

Spinal cord compression due to extramedullary hematopoiesis in the proliferative phase of polycythemia vera.

Extramedullary hematopoiesis is a common accompaniment of a variety of hematologic diseases such as hereditary spherocytosis, thalassemia and myelofibrosis. The association of extramedullary hematopoiesis with polycythemia vera in the proliferative phase is much less usual. We report a patient who presented with paraplegia due to spinal cord compression; clinical investigation revealed a paravertebral hematopoietic tumor, and the diagnosis of polycythemia vera was then established.

[Botulinum toxin in blepharospasm, in hemifacial spasm, and in cervical dystonia: results in 33 patients]. / Toxina botulínica no blefaroespasmo, no espasmo hemifacial e na distonia cervical: resultados em 33 pacientes.

The effects of botulinum toxin type A were studied in 33 patients with dystonia (12 blepharospasms, 10 hemifacial spasms and 11 spasmodic torticollis). A rate scale was used to evaluate the severity of the dystonic movements, before and two weeks after each injection. Among blepharospasm patients, eight were female and four were male; the mean age was 57.7 years; the mean time of the disease duration was four years. Three had familial history for similar disease; nine were essential and three had used neuroleptic drugs (tardive dystonia). The mean dose used was 51.3 U, with a mean time of beneficial effects of 2.8 months. For 22 injections and reinjections, 14 (63.7%) showed an excellent result, five (22.7%) good and three (13.6%) null. In the hemifacial spasm group, eight were female and two male; the mean age was 52.6 years; the mean time of the disease duration was 7.4 years; eight were essential and two post-paralytic. The mean dose used was 32 U. From the total of 15 injections and reinjections, all of them (100%) had an excellent result, with a mean time of beneficial effect of 3.4 months. Among the cervical dystonic patients, eight were male and three female; the mean age was 44.2 years; the mean time of the disease duration was 12.2 years; six had essential dystonia, three had used neuroleptic drugs and two had familial history for similar disease. The mean dose used was 238.6 U, with the mean duration of effect of 3.5 months. From the total of 20 injections and reinjections, 18 (90%) had good result, one (5%) mild and one (5%) null.(ABSTRACT TRUNCATED AT 250 WORDS)

[Tics and Gilles de la Tourette syndrome]. / Tiques e síndrome de Gilles de la Tourette.

The concept of tic was developed at the end of the XIX century, emerging from the "chaos of choreas". Tic is defined as involuntary contractions of agonist and antagonist muscles in one or more parts of the body. It can be suppressed by voluntary efforts for seconds or hours, followed by exacerbations. Gilles de la Tourette's original article was published in 1885, in which he described nine patients with tics, and vocalisations. The pathogenesis of Gilles de la Tourette syndrome remained obscure. However, three factors have been considered: the neurochemical factor, related to the increased dopaminergic activity at the basal ganglia; the genetic factor and the non-genetic factors, for which environment more than genetic factors are involved. Pathologic examinations failed to reveal structural lesions, but PET studies showed metabolic hypofunction on the frontal, cingulate and possibly insular cortex, and on the inferior corpus striatum. The motor tics as well as the vocal tics can be simple or complex and are present in all patients. Other signs can be added to the previous tics: sensory tics, echophilia, coprophilia, obsessions, compulsions and impulsions. Diagnostic criteria of Gilles de la Tourette syndrome are based on: age of onset; presence of motor and vocal tics; voluntary suppression of the movements; variation in number, type, location and severity of tics; duration of more than one year. Haloperidol is the drug of choice for the treatment of Tourette's syndrome.

Involuntary movements and AIDS: report of seven cases and review of the literature.

We studied 1086 AIDS patients in the last six years. Of these 389 (35.82%) had neurological manifestation and 7 (1.8%) male patients had abnormal involuntary movements (parkinsonism in 3, hemichorea-hemiballism in 2, spinal myoclonus in 1 and rubral tremor in another). All patients were men, 5 white and 2 black. Four were homosexual, 2 drug-users and 1 bisexual. The mean age was 33.14 years. The time between AIDS diagnosis and the onset of movement disorders was 23.8 months in 5 patients and in 2 it was the first symptom. The parkinsonian patients did not show any opportunistic infection in connection with the neurological symptoms but in the remaining four cases this relationship was suggested. The data showed that not only the opportunistic infection but also the AIDS virus may play an important role on the development of involuntary movements.

Spinal myoclonus: report of four cases.

Four cases of spinal myoclonus are described, three males and one female. The mean age was 51 years (28-75 years). The mean time between the onset of the myelopathy and the myoclonic jerks was 4.3 months (1-8 months). The involuntary movements were determined by trauma, Devic's disease, tuberculous myelopathy and tumor. Three patients had spastic paraplegia with bilateral myoclonus more evident on the right side. The fourth patient had a flaccid paraplegia with symmetrical jerks. The data suggest that different processes (trauma, demyelinating, infection and tumor) affecting the spinal cord may cause the same type of involuntary movements.

A case of periodic sweating associated with a subarachnoid cyst and multifocal dystonia.

A case of periodic sweating with multifocal dystonia is reported in a 60-year-old woman. At the age of 48 years, she presented with involuntary twisting of the lower face on the right. Six months later she noticed similar movements in the head and right arm. Four years later she began having attacks of generalized sweating over the whole face, anterior region of the trunk and both arms. The attacks occurred hourly each and every day. They lasted for about 10 min and were followed by voluntary urinary voiding. The biochemical and laboratory investigations showed no abnormalities except for the luteinizing hormone and follicle-stimulating hormone values that were below normal. The computerized tomography and magnetic resonance imaging scans revealed a suprasellar cyst. Clonazepam was introduced with partial improvement of the dystonic movements but not of the sweating attacks. The patient refused surgery. Acetazolamide was added and reduced the sweating attacks. We speculate that the periodic sweating may be related to cerebrospinal fluid production and cyst enlargement, hence the ability of acetazolamide, which reduces cerebrospinal fluid production, to reduce attacks.

Segmental myoclonus and basilar artery. Giant aneurysm. Case report.

A 70 years-old man was admitted at our hospital because of unstable angina pectoris. He had essential hypertension and right hemiplegia from a ischemic stroke two years before admission. On neurologic examination, it was found mental disorientation, unstable emotionality, right spastic hemiparesis with right Babinski sign, and segmental myoclonus affecting the superior lip and the palate (palatal nystagmus) on the right side. On the CT scan, a giant aneurysm of the basilar artery was detected. We conclude that the segmental myoclonus could be explained by ischemic lesions in the Guillain-Mollaret triangle.

[Ultrastructural analysis of the cerebrospinal fluid in patients with Parkinson disease]. / Análise ultra-estrutural do Líquido cefalorraquiano de parkinsonianos.

Ultrastructural cerebrospinal fluid of 20 parkinsonian patients examined by negative staining showed not recognizable structures thought to be of viral origin in 6 cases (30%). However, mortality rate analysis failed to disclose significant differences between the inoculated animals. Either artefact or not, such structures deserve to be reported.

[Results of intracerebral inoculation of the cerebrospinal fluid of patients with Parkinson disease in experimental animals]. / Resultados das inoculações intracerebrais de líquido cefalorraquiano de parkinsonianos em animais de experimentações.

Intracerebral inoculation of parkinsonian's cerebrospinal fluid were carried out in 720 mice, under strict observation during 48 weeks. The inoculations led to a mortality rate of 157 mice (21.8%), being 31% (76) in the first, 17% (41) in the second, and 16% (40) after the third one. High mortality rates occurred, most prevalent in the first inoculation and during the first 7 weeks. Dendrite tumefaction and disintegration as well as nerve cell swelling were the ultrastructural changes observed in the brain of mice.