Epigenetic effects of folate and related B vitamins on brain health throughout life: Scientific substantiation and translation of the evidence for health improvement strategies.

Suboptimal status of folate and/or interrelated B vitamins (B12 , B6 and riboflavin) can perturb one-carbon metabolism and adversely affect brain development in early life and brain function in later life. Human studies show that maternal folate status during pregnancy is associated with cognitive development in the child, whilst optimal B vitamin status may help to prevent cognitive dysfunction in later life. The biological mechanisms explaining these relationships are not clear but may involve folate-related DNA methylation of epigenetically controlled genes related to brain development and function. A better understanding of the mechanisms linking these B vitamins and the epigenome with brain health at critical stages of the lifecycle is necessary to support evidence-based health improvement strategies. The EpiBrain project, a transnational collaboration involving partners in the United Kingdom, Canada and Spain, is investigating the nutrition-epigenome-brain relationship, particularly focussing on folate-related epigenetic effects in relation to brain health outcomes. We are conducting new epigenetics analysis on bio-banked samples from existing well-characterised cohorts and randomised trials conducted in pregnancy and later life. Dietary, nutrient biomarker and epigenetic data will be linked with brain outcomes in children and older adults. In addition, we will investigate the nutrition-epigenome-brain relationship in B vitamin intervention trial participants using magnetoencephalography, a state-of-the-art neuroimaging modality to assess neuronal functioning. The project outcomes will provide an improved understanding of the role of folate and related B vitamins in brain health, and the epigenetic mechanisms involved. The results are expected to provide scientific substantiation to support nutritional strategies for better brain health across the lifecycle.

Larvicidal activity of the skin secretion of Rhinella marina and Rhaebo guttatus (Anura: Bufonidae) against the Brazilian malaria vector, Anopheles darlingi (Diptera: Culicidae)

@#Malaria, a mosquito-borne disease, is caused by protozoa of the genus Plasmodium and constitutes a serious public health problem. Because current insecticides used to control malaria face resistance due to continuous use, new alternatives are prompted. Considering this context, and the insecticidal potential of vertebrate venoms/secretions, crude and methanolic extracts from two frog species were tested as larvicides against Anopheles darlingi. Skin secretions of Rhinella marina and Rhaebo guttatus were obtained by manual stimulation. Then, methanol was added to obtain steroidal fractions from both venoms. Mosquitos were captured in suburban areas of Porto Velho and An. darlingi females were later fed with blood and stimulated to oviposit. The larvae were fed with fish food until the 3rd and 4th instars. For the larvicidal assays, crude secretions and methanolic fractions of both frog species were evaluated, and larvae mortality was recorded after 48 hours. Crude extracts and steroidal fractions from both species had larvicidal effects, with an LC50 of 127.5 and 133 ppm for the crude extract and steroidal fraction of R. marina, and an LC50 of 37.5 and 35.8 ppm for the crude extract and steroidal secretion of R. guttatus, respectively. The present work reports for the first time the larvicidal effects of the skin secretions from bufonid species occurring in the western Amazon region. Further studies should be carried out to investigate the purified components responsible for the observed activity.

Antimyotoxic Activity of Synthetic Peptides Derived from Bothrops atrox Snake Gamma Phospholipase A2 Inhibitor Selected by Virtual Screening.

BACKGROUND: Several studies have aimed to identify molecules that inhibit the toxic actions of snake venom phospholipases A2 (PLA2s). Studies carried out with PLA2 inhibitors (PLIs) have been shown to be efficient in this assignment. OBJECTIVE: This work aimed to analyze the interaction of peptides derived from Bothrops atrox PLIγ (atPLIγ) with a PLA2 and to evaluate the ability of these peptides to reduce phospholipase and myotoxic activities. METHODS: Peptides were subjected to molecular docking with a homologous Lys49 PLA2 from B. atrox venom modeled by homology. Phospholipase activity neutralization assay was performed with BthTX-II and different ratios of the peptides. A catalytically active and an inactive PLA2 were purified from the B. atrox venom and used together in the in vitro myotoxic activity neutralization experiments with the peptides. RESULTS: The peptides interacted with amino acids near the PLA2 hydrophobic channel and the loop that would be bound to calcium in Asp49 PLA2. They were able to reduce phospholipase activity and peptides DFCHNV and ATHEE reached the highest reduction levels, being these two peptides the best that also interacted in the in silico experiments. The peptides reduced the myotubes cell damage with a highlight for the DFCHNV peptide, which reduced by about 65%. It has been suggested that myotoxic activity reduction is related to the sites occupied in the PLA2 structure, which could corroborate the results observed in molecular docking. CONCLUSION: This study should contribute to the investigation of the potential of PLIs to inhibit the toxic effects of PLA2s.

Exploring and understanding the functional role, and biochemical and structural characteristics of an acidic phospholipase A2, AplTx-I, purified from Agkistrodon piscivorus leucostoma snake venom.

Phospholipases A2 (PLA2s) constitute a class of extensively studied toxins, isolated from snake venoms. Basic PLA2 isoforms mediate various toxicological effects, while the acidic isoforms generally have higher enzymatic activities, but do not promote evident toxic effects. The functions of these acidic isoforms in snake venoms are still not completely understood and more studies are needed to characterize the biological functions and diversification of acidic toxins in order to justify their abundant presence in these secretions. Recently, Lomonte and collaborators demonstrated, in a proteomic and toxicological study, high concentrations of PLA2s in the venom of Agkistrodon piscivorus leucostoma. We have, herein, purified and characterized an acidic PLA2 from this snake venom, denominated AplTx-I, in order to better understand its biochemical and structural characteristics, as well as its biological effects. AplTx-I was purified using two chromatographic steps, in association with enzymatic and biological assays. The acidic toxin was found to be one of the most abundant proteins in the venom of A. p. leucostoma; the protein was monomeric with a molecular mass of 13,885.8 Da, as identified by mass spectrometry ESI-TOF and electrophoresis. The toxin has similar primary and tridimensional structures to those of other acidic PLA2s, a theoretical and experimental isoelectric point of ≈5.12, and a calcium-dependent enzyme activity of 25.8985 nM/min/mg, with maximum values at 37 °C and pH 8.0. Despite its high enzymatic activity on synthetic substrate, AplTx-I did not induce high or significant myotoxic, coagulant, anticoagulant, edema, neuromuscular toxicity in mouse phrenic nerve-diaphragm preparations or antibacterial activities. Interestingly, AplTx-I triggered a high and selective neuromuscular toxicity in chick biventer cervicis preparations. These findings are relevant to provide a deeper understanding of the pharmacology, role and diversification of acidic phospholipase A2 isoforms in snake venoms.

CoaTx-II, a new dimeric Lys49 phospholipase A2 from Crotalus oreganus abyssus snake venom with bactericidal potential: Insights into its structure and biological roles.

Snake venoms are rich and intriguing sources of biologically-active molecules that act on target cells, modulating a diversity of physiological functions and presenting promising pharmacological applications. Lys49 phospholipase A2 is one of the multifunctional proteins present in these complex secretions and, although catalytically inactive, has a variety of biological activities, including cytotoxic, antibacterial, inflammatory, antifungal activities. Herein, a Lys49 phospholipase A2, denominated CoaTx-II from Crotalus oreganus abyssus, was purified and structurally and pharmacologically characterized. CoaTx-II was isolated with a high degree of purity by a combination of two chromatographic steps; molecular exclusion and reversed-phase high performance liquid chromatography. This toxin is dimeric with a mass of 13868.2 Da (monomeric form), as determined by mass spectrometry. CoaTx-II is rich in Arg and Lys residues and displays high identity with other Lys49 PLA2 homologues, which have high isoelectric points. The structural model of dimeric CoaTx-II shows that the toxin is non-covalently stabilized. Despite its enzymatic inactivity, in vivo CoaTx-II caused local muscular damage, characterized by increased plasma creatine kinase and confirmed by histological alterations, in addition to an inflammatory activity, as demonstrated by mice paw edema induction and pro-inflammatory cytokine IL-6 elevation. CoaTx-II also presents antibacterial activity against gram negative (Pseudomonas aeruginosa 31NM, Escherichia coli ATCC 25922) and positive (Staphyloccocus aureus BEC9393 and Rib1) bacteria. Therefore, data show that this newly purified toxin plays a central role in mediating the degenerative events associated with envenomation, in addition to demonstrating antibacterial properties, with potential for use in the development of strategies for antivenom therapy and combating antibiotic-resistant bacteria.

Biochemical and functional studies of ColTx-I, a new myotoxic phospholipase A2 isolated from Crotalus oreganus lutosus (Great Basin rattlesnake) snake venom.

Commonly, phospholipases A2 (PLA2s) play key roles in the pathogenesis of the local tissue damage characteristic of crotaline and viperine snake envenomations. Crotalus oreganus lutosus snake venom has not been extensively studied; therefore, the characterization of its components represents a valuable biotechnological tool for studying pathophysiological processes of envenoming and for gaining a deeper understanding of its biological effects. In this study, for the first time, a basic PLA2 myotoxin, ColTx-I, was purified from C. o. lutosus through two chromatographic steps. ColTx-I is monomeric with calculated molecular mass weight (Mw) of 14,145 Da and a primary structure closely related to basic PLA2s from viperid venoms. The pure enzyme has a specific activity of 15.87 ± 0.65 nmol/min/mg at optimal conditions (pH 8.0 and 37 °C). ColTx-I activity was found to be dependent on Ca(2+), as its substitution by other ionic species as well as the addition of chelating agents significantly reduced its phospholipase activity. In vivo, ColTx-I triggered dose-dependent inflammatory responses, measured using the paw edema model, with an increase in IL-6 levels, systemic and local myotoxicity, characterized by elevated plasma creatine kinase activity. ColTx-I induced a complex series of degenerative events associated with edema, inflammatory infiltrate and skeletal muscle necrosis. These biochemical and functional results suggest that ColTx-I, a myotoxic and inflammatory mediator, plays a relevant role in C. o. lutosus envenomation. Thus, detailed studies on its mechanism of action, such as evaluating the synergism between ColTx-I and other venom components may reveal targets for the development of more specific and effective therapies.

Alkylation of histidine residues of Bothrops jararacussu venom proteins and isolated phospholipases A2: a biotechnological tool to improve the production of antibodies.

Crude venom of Bothrops jararacussu and isolated phospholipases A2 (PLA2) of this toxin (BthTX-I and BthTX-II) were chemically modified (alkylation) by p-bromophenacyl bromide (BPB) in order to study antibody production capacity in function of the structure-function relationship of these substances (crude venom and PLA2 native and alkylated). BthTX-II showed enzymatic activity, while BthTX-I did not. Alkylation reduced BthTX-II activity by 50% while this process abolished the catalytic and myotoxic activities of BthTX-I, while reducing its edema-inducing activity by about 50%. Antibody production against the native and alkylated forms of BthTX-I and -II and the cross-reactivity of antibodies to native and alkylated toxins did not show any apparent differences and these observations were reinforced by surface plasmon resonance (SPR) data. Histopathological analysis of mouse gastrocnemius muscle sections after injection of PBS, BthTX-I, BthTX-II, or both myotoxins previously incubated with neutralizing antibody showed inhibition of the toxin-induced myotoxicity. These results reveal that the chemical modification of the phospholipases A2 (PLA2) diminished their toxicity but did not alter their antigenicity. This observation indicates that the modified PLA2 may provide a biotechnological tool to attenuate the toxicity of the crude venom, by improving the production of antibodies and decreasing the local toxic effects of this poisonous substance in animals used to produce antivenom.

A novel phospholipase A2 (D49) from the venom of the Crotalus oreganus abyssus (North American Grand canyon rattlesnake).

Currently, Crotalus viridis was divided into two species: Crotalus viridis and Crotalus oreganus. The current classification divides "the old" Crotalus viridis into two new and independent species: Crotalus viridis (subspecies: viridis and nuntius) and Crotalus oreganus (subspecies: abyssus, lutosus, concolor, oreganus, helleri, cerberus, and caliginis). The analysis of a product from cDNA (E6d), derived from the gland of a specie Crotalus viridis viridis, was found to produce an acid phospholipase A2. In this study we isolated and characterized a PLA2 (D49) from Crotalus oreganus abyssus venom. Our studies show that the PLA2 produced from the cDNA of Crotalus viridis viridis (named E6d) is exactly the same PLA2 primary sequence of amino acids isolated from the venom of Crotalus oreganus abyssus. Thus, the PLA2 from E6d cDNA is actually the same PLA2 presented in the venom of Crotalus oreganus abyssus and does not correspond to the venom from Crotalus viridis viridis. These facts highlight the importance of performing more studies on subspecies of Crotalus oreganus and Crotalus viridis, since the old classification may have led to mixed results or mistaken data.

Snake venom PLA2s inhibitors isolated from Brazilian plants: synthetic and natural molecules.

Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2 (PLA2s) are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2 inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites.

Action of two phospholipases A2 purified from Bothrops alternatus snake venom on macrophages.

The in vitro effects of BaltTX-I, a catalytically inactive Lys49 variant of phospholipase A2 (PLA2), and BaltTX-II, an Asp49 catalytically active PLA2 isolated from Bothrops alternatus snake venom, on thioglycollate-elicited macrophages (TG-macrophages) were investigated. At non-cytotoxic concentrations, the secretory PLA2 BaltTX-I but not BaltTX-II stimulated complement receptor-mediated phagocytosis. Pharmacological treatment of TG-macrophages with staurosporine, a protein kinase C (PKC) inhibitor, showed that this kinase is involved in the increase of serum-opsonized zymosan phagocytosis induced by BaltTX-I but not BaltTX-II secretory PLA2, suggesting that PKC may be involved in the stimulatory effect of this toxin in serum-opsonized zymosan phagocytosis. Moreover, BaltTX-I and -II induced superoxide production by TG-macrophages. This superoxide production stimulated by both PLA2s was abolished after treatment of cells with staurosporine, indicating that PKC is an important signaling pathway for the production of this radical. Our experiments showed that, at non-cytotoxic concentrations, BaltTX-I may upregulate phagocytosis via complement receptors, and that both toxins upregulated the respiratory burst in TG-macrophages.

Purification of a 6.5 kDa protease inhibitor from Amazon Inga umbratica seeds effective against serine proteases of the boll weevil Anthonomus grandis.

A 6.5 kDa serine protease inhibitor was purified by anion-exchange chromatography from the crude extract of the Inga umbratica seeds, containing inhibitor isoforms ranging from 6.3 to 6.7 kDa and protease inhibitors of approximately 19 kDa. The purified protein was characterized as a potent inhibitor against trypsin and chymotrypsin and it was named I. umbratica trypsin and chymotrypsin inhibitor (IUTCI). MALDI-TOF spectra of the IUTCI, in the presence of DTT, showed six disulfide bonds content, suggesting that this inhibitor belongs to Bowman-Birk family. The circular dichroism spectroscopy indicates that IUTCI is predominantly formed by unordered and beta-sheet secondary structure. It was also characterized, by fluorescence spectroscopy, as a stable protein at range of pH from 5.0 to 7.0. Moreover, this inhibitor at concentration of 75 microM presented a remarkable inhibitory activity (60%) against digestive serine proteases from boll weevil Anthonomus grandis, an important economical cotton pest.

[Brain vasculitis associated with drugs]. / Vasculitis cerebral asociada a drogas.

INTRODUCTION: Vasculitis or angiitis is the term used to define the inflammation of the vessels, either blood or lymphatic, which causes may be primary related to immunological disorders, or secondary, with great variety of causal factors. CASE REPORT: We present a very uncommon case of a 36 year old man with brain vasculitis associated with drugs with very peculiar characteristics in the imaging studies and with definite diagnosis through histopathology obtained by biopsy, which differs from the few reports in the literature until our days. CONCLUSIONS: Our report is an uncommon case of cerebral vasculitis whose clinical features were confusing with impressing neuroimaging studies that showed possible lesions due to vasculitis that was confirmed through a cerebral biopsy and considering that the immunological tests were negative for a primary vasculitic process, we concluded that it was a vasculitis secondary to drug abuse which represents a special interest in view of the few existing reports in literature with definite diagnostic methods, such as cerebral biopsy or autopsy.

Vasculitis cerebral asociada a drogas / Brain Vasculitis associated with drugs

Introduction. Vasculitis or angiitis is the term used to define the inflammation of the vessels, either blood or lymphatic, which causes may be primary related to immunological disorders, or secondary, with great variety of causal factors. Case report. We present a very uncommon case of a 36 year old man with brain vasculitis associated with drugs with very peculiar characteristics in the imaging studies and with definite diagnosis through histopathology obtained by biopsy, which differs from the few reports in the literature until our days. Conclusions. Our report is an uncommon case of cerebral vasculitis whose clinical features were confusing with impressing neuroimaging studies that showed possible lesions due to vasculitis that was confirmed through a cerebral biopsy and considering that the immunological tests were negative for a primary vasculitic process, we concluded that it was a vasculitis secondary to drug abuse which represents a special interest in view of the few existing reports in literature with definite diagnostic methods, such as cerebral biopsy or autopsy (AU)

Introducción. Vasculitis, o angeítis, es el término que se emplea para definir la inflamación de los vasos, ya sean sanguíneos o linfáticos, cuyas causas pueden ser primarias, relacionada más con alteraciones inmunológicas, o secundarias, con una gran heterogeneidad de factores causales. Caso clínico. Presentamos el caso poco común de un hombre de 36 años de edad con vasculitis cerebral asociada a la utilización de drogas, el cual cuenta con estudios de imagen peculiares, pero con confirmación histopatológica de una muestra obtenida mediante biopsia cerebral, la cual difiere de los pocos informes similares que existen en la literatura hasta la actualidad. Conclusiones. Este comunicado corresponde a un caso poco común de vasculitis cerebral cuyas manifestaciones iniciales eran confusas, con estudios de neuroimagen que mostraron posibles lesiones por vasculitis, lo que se corroboró mediante biopsia cerebral; considerando que las pruebas inmunológicas resultaron negativas para un proceso vasculítico primario, concluimos, por los antecedentes del paciente, que se trataba de una vasculitis secundaria a abuso de drogas; esto tiene un interés especial, dados los escasos comunicados existentes en la literatura con métodos diagnósticos definitivos, como la biopsia cerebral o la necropsia (AU)

[Ergotism. A case report and review of the literature]. / Ergotismo. Presentación de un caso y revisión de la bibliografía.

INTRODUCTION: Ergotism is characterised by an intensive generalised vasoconstriction of small and large blood vessels. The symptoms derive from the regional ischemia caused by the vasospasm produced by ergotamine. Nowadays, ergotism is almost exclusively due to the excessive ingestion of ergotamine tartrate used in the treatment of migraine. The main treatment consists in withdrawing the medication. CASE REPORT: Our study involves a 53-year-old male with a history of migraine since his youth, who was treated with ergotaminic preparations up until the day before admission to hospital. He was admitted because of a 7-day history of symptoms including bilateral and symmetrical anaesthesia of the fingers and a general feeling of weakness, associated with intense pain and cyanosis of the right thenar eminence. On admission, it was not possible to measure his AT in the upper limbs and his peripheral pulses dropped in a generalised manner. Aetiologies involving vasculitis were ruled out. An angiography study showed segmented stenosis of arteries in the upper and lower limbs. Ergotaminic agents were withdrawn and nifedipine was indicated. The symptoms disappeared, the physical examination was normal and results of a control angiography study were also normal. CONCLUSIONS: Ergotamine intoxication can be detected by a thorough interview and physical examination; it should be suspected when faced with symptoms that are compatible with vasospasms and a history of ingestion of the drug, in the absence of any prothrombotic, liver, kidney or vasculitic pathology. This condition is treated by withdrawing the drug and administration of vasodilators if the symptoms are intense. In this paper, we review the history, pathophysiology, initial symptoms and signs, diagnosis and treatment of ergotamine poisoning.

Ergotismo. Presentación de un caso y revisión de la bibliografía / Ergotism. A case report and review of the literature

Introducción. El ergotismo se caracteriza por una intensa y generalizada vasoconstricción de los vasos sanguíneos pequeños y grandes. Los síntomas resultan de la isquemia regional causada por el vasoespasmo que produce la ergotamina. En la actualidad, el ergotismo resulta casi exclusivamente de la ingesta excesiva de tartrato de ergotamina para el tratamiento de la migraña. El principal tratamiento es la suspensión del fármaco. Caso clínico. Se trata de un hombre de 53 años con historia de migraña desde su juventud, tratada con ergotamínicos hasta un día antes de su ingreso. Ingresó por manifestaciones de siete días de evolución, con anestesia bilateral y simétrica de los dedos de las manos y sensación de debilidad generalizada, asociados a dolor intenso y cianosis de la eminencia tenar derecha. Cuando ingresó no fue posible medir la tensión arterial en las extremidades superiores, y sus pulsos periféricos estaban disminuidos de manera generalizada. Se descartaron etiologías de vasculitis. Una angiografía mostró estenosis segmentaria de las arterias en las extremidades superiores e inferiores. Se suspendieron los ergotamínicos y se indicó nifedipina. La sintomatología desapareció, la exploración física fue normal y una angiografía de control fue normal. Conclusiones. La intoxicación por ergotamina puede detectarse mediante un interrogatorio y exploración física completos; se debe sospechar ante manifestaciones compatibles con vasoespasmo y el antecedente de ingesta del fármaco, en ausencia de patología protrombótica o vasculítica, hepatopatía o nefropatía. El tratamiento del cuadro es con suspensión del fármaco, y vasodilatadores si las manifestaciones son intensas. En este artículo se revisa la historia, fisiopatología, síntomas y signos de presentación, diagnóstico y tratamiento de la intoxicación por ergotamina

Introduction. Ergotism is characterised by an intensive generalised vasoconstriction of small and large blood vessels. The symptoms derive from the regional ischemia caused by the vasospasm produced by ergotamine. Nowadays, ergotism is almost exclusively due to the excessive ingestion of ergotamine tartrate used in the treatment of migraine. The main treatment consists in withdrawing the medication. Case report. Our study involves a 53-year-old male with a history of migraine since his youth, who was treated with ergotaminic preparations up until the day before admission to hospital. He was admitted because of a 7-day history of symptoms including bilateral and symmetrical anaesthesia of the fingers and a general feeling of weakness, associated with intense pain and cyanosis of the right thenar eminence. On admission, it was not possible to measure his AT in the upper limbs and his peripheral pulses dropped in a generalised manner. Aetiologies involving vasculitis were ruled out. An angiography study showed segmented stenosis of arteries in the upper and lower limbs. Ergotaminic agents were withdrawn and nifedipine was indicated. The symptoms disappeared, the physical examination was normal and results of a control angiography study were also normal. Conclusions. Ergotamine intoxication can be detected by a thorough interview and physical examination; it should be suspected when faced with symptoms that are compatible with vasospasms and a history of ingestion of the drug, in the absence of any prothrombotic, liver, kidney or vasculitic pathology. This condition is treated by withdrawing the drug and administration of vasodilators if the symptoms are intense. In this paper, we review the history, pathophysiology, initial symptoms and signs, diagnosis and treatment of ergotamine poisoning

[Non-convulsive epileptic status associated with Lafora disease: two case reports]. / Estado epiléptico no convulsivo asociado a enfermedad de Lafora: presentación de dos casos.

INTRODUCTION: Lafora s disease is a type of progressive myoclonic epilepsy with poor prognosis, is characterized by myoclonic crisis, tonic clonic seizures, absence or partial complex seizures and other neurological manifestations with a progressive course and a poor response to the treatment. It has not been considered as a cause of epileptic status. CASE REPORTS: Two women without important past medical history with normal psychomotor development before their suffering, with manifestations of 2 years of evolution the first one and 8 years on the second case characterized by myoclonic generalized, partial complex seizures and progressive deterioration of the mental functions that joined to our institution in a non convulsive epileptic status and they featured with a different evolution. The first patient with favorable control of the event with a single medication and functionality recover later, the second one with torpid evolution complicated with an epileptic status convulsive widespread condition and a prolonged permanency in the unit of intensive therapy. In both patients the diagnosis of Lafora s disease was established based in the findings of the skin axilar biopsy. DISCUSSION AND CONCLUSION: We believe that Lafora s disease must be suspected as a probable cause of non convulsive epileptic status in patients with myoclonic epilepsy associated with other neurological manifestations and a refractary response to the medical treatment. The evolution and clinical response will depend on the evolutionary stage of the disease.

[Diabetic neuropathy: vascular disease?]. / Neuropatía diabética: una enferemedad vascular?

INTRODUCTION: The major neurologic complications of diabetes are: 1) Neuropathy, both peripheral and autonomic, with principal manifestations in the lower limbs; 2) Microvascular disease, mainly affecting the retina, resulting in blindness; and 3) Macrovascular disease, presenting with atherosclerosis in the cerebral arteries causing ischemic cerebrovascular disease and stroke. METHOD: The definition of diabetic neuropathy has changed over the last 50 years. Over the last 20 years there have been three main pathogenetic theories to explain diabetic neuropathy: the polyol pathway theory, the microvascular theory, and the glycosylation end product theory. It is apparent that several pathophysiologic factors probably operate simultaneously, and it may be too simplistic to attempt to explain the many clinical and pathologic findings of diabetic neuropathy through a single theory. Diabetic peripheral neuropathy is not caused by large vessel peripheral vascular disease, however, it does appear that small vessel disease plays a role. CONCLUSION: It seems likely, that microangiopathy on the one hand and changes of various metabolic pathways due to hyperglycemia on the other hand are much more related to each other than it was suggested previously.

Neuropatía diabética: ¿una enfermedad vascular? / Diabetic neuropathy: vascular disease?

Introducción. Las principales complicaciones neurológicas de la diabetes son: 1) Neuropatía periférica y autonómica, cuyas manifestaciones principales ocurren en las extremidades inferiores; 2) Enfermedad microvascular, que afecta principalmente a la retina y desencadena ceguera, y 3) Enfermedad macrovascular, presente con aterosclerosis en las arterias cerebrales y que causa enfermedad isquémica cerebrovascular. Desarrollo. La definición de la neuropatía diabética (ND) ha cambiado en los últimos 50 años; en los últimos veinte se han propuesto tres teorías patogénicas principales para explicar la ND: la teoría de la vía poliol, la teoría microvascular y la teoría del producto final de la glucosilación. Probablemente, varios factores patofisiológicos actúan simultáneamente, y puede parecer muy simplista explicar que muchas manifestaciones clínicas y hallazgos patológicos en la ND pueden ser resultado de un solo mecanismo. La ND periférica no la ocasiona la enfermedad vascular periférica de grandes vasos; sin embargo, parece que la enfermedad de pequeños vasos desempeña un papel importante. Conclusión. Es probable que la microangiopatía, por un lado, y las alteraciones de varias vías metabólicas por la hiperglucemia, por otro, se relacionen más entre sí que como se había descrito anteriormente (AU)

Introduction. The major neurologic complications of diabetes are: 1) Neuropathy, both peripheral and autonomic, with principal manifestations in the lower limbs; 2) Microvascular disease, mainly affecting the retina, resulting in blindness; and 3) Macrovascular disease, presenting with atherosclerosis in the cerebral arteries causing ischemic cerebrovascular disease and stroke. Method. The definition of diabetic neuropathy has changed over the last 50 years. Over the last 20 years there have been three main pathogenetic theories to explain diabetic neuropathy: the polyol pathway theory, the microvascular theory, and the glycosylation end product theory. It is apparent that several pathophysiologic factors probably operate simultaneously, and it may be too simplistic to attempt to explain the many clinical and pathologic findings of diabetic neuropathy through a single theory. Diabetic peripheral neuropathy is not caused by large-vessel peripheral vascular disease, however, it does appear that small-vessel disease plays a role. Conclusion. It seems likely, that microangiopathy on the one hand and changes of various metabolic pathways due to hyperglycemia on the other hand are much more related to each other than it was suggested previously (AU)