Hypothalamic A11 Nuclei Regulate the Circadian Rhythm of Spinal Mechanonociception through Dopamine Receptors and Clock Gene Expression.

Several types of sensory perception have circadian rhythms. The spinal cord can be considered a center for controlling circadian rhythms by changing clock gene expression. However, to date, it is not known if mechanonociception itself has a circadian rhythm. The hypothalamic A11 area represents the primary source of dopamine (DA) in the spinal cord and has been found to be involved in clock gene expression and circadian rhythmicity. Here, we investigate if the paw withdrawal threshold (PWT) has a circadian rhythm, as well as the role of the dopaminergic A11 nucleus, DA, and DA receptors (DR) in the PWT circadian rhythm and if they modify clock gene expression in the lumbar spinal cord. Naïve rats showed a circadian rhythm of the PWT of almost 24 h, beginning during the night-day interphase and peaking at 14.63 h. Similarly, DA and DOPAC's spinal contents increased at dusk and reached their maximum contents at noon. The injection of 6-hydroxydopamine (6-OHDA) into the A11 nucleus completely abolished the circadian rhythm of the PWT, reduced DA tissue content in the lumbar spinal cord, and induced tactile allodynia. Likewise, the repeated intrathecal administration of D1-like and D2-like DA receptor antagonists blunted the circadian rhythm of PWT. 6-OHDA reduced the expression of Clock and Per1 and increased Per2 gene expression during the day. In contrast, 6-OHDA diminished Clock, Bmal, Per1, Per2, Per3, Cry1, and Cry2 at night. The repeated intrathecal administration of the D1-like antagonist (SCH-23390) reduced clock genes throughout the day (Clock and Per2) and throughout the night (Clock, Per2 and Cry1), whereas it increased Bmal and Per1 throughout the day. In contrast, the intrathecal injection of the D2 receptor antagonists (L-741,626) increased the clock genes Bmal, Per2, and Per3 and decreased Per1 throughout the day. This study provides evidence that the circadian rhythm of the PWT results from the descending dopaminergic modulation of spinal clock genes induced by the differential activation of spinal DR.

Hipertrigliceridemia severa durante el embarazo

Resumen: Durante el embarazo se producen cambios a nivel de la concentración de los lípidos debido a cambios fisiológicos con el fin de favorecer una adecuada nutrición fetal, estos cambios rara vez tienen consecuencias clínicas. Se presenta el caso clínico de una gestante que a las 31 semanas de edad gestacional se le diagnostica un estado hipertensivo del embarazo, constatándose hipertrigliceridemia severa con alto riesgo de pancreatitis. Se realizó recambio plasmático terapéutico y gemfibrozilo, con buena respuesta clínica.

Abstract: During pregnancy, changes occur at the level of lipid concentration due to physiological changes in order to promote adequate fetal nutrition, these changes rarely have clinical consequences. The clinical case of a pregnant woman is presented who at 31 weeks of gestational age is diagnosed with a hypertensive state of pregnancy, confirming severe hypertriglyceridemia with a high risk of pancreatitis. Therapeutic plasma exchange and gemfibrozil were performed, with a good clinical response.

Resumo: Durante a gravidez ocorrem alterações ao nível da concentração de lípidos devido a alterações fisiológicas de forma a promover uma nutrição fetal adequada, estas alterações raramente têm consequências clínicas. Apresenta-se o caso clínico de uma grávida que às 31 semanas de idade gestacional é diagnosticada com estado hipertensivo da gravidez, confirmando hipertrigliceridemia grave com elevado risco de pancreatite. Foi realizada plasmaférese terapêutica e gemfibrozil, com boa resposta clínica.

Ganglionopatía sensitiva. Caso clínico y revisión de la bibliografía

Resumen: Las ganglionopatías sensitivas son un grupo raro de neuropatías sensitivas que pueden estar asociadas a neoplasias como el cáncer broncopulmonar. Su presentación clínica y resultado de estudio eléctrico son característicos. El tratamiento depende de la causa subyacente, siendo fundamental su hallazgo oportuno, ya que el inicio precoz impacta en el pronóstico del paciente. Reportamos el caso de una paciente que se presentó con parestesias de distribución atípica, dolor neuropático y ataxia. El estudio eléctrico evidenció una ganglionopatía sensitiva, de cuyo estudio etiológico surge el diagnóstico de carcinoma broncopulmonar.

Abstract: Sensory ganglionopathies are a rare group of sensory neuropathies that can be associated with neoplasms such as bronchopulmonary cancer. Its clinical presentation and electrical study result are characteristic. Treatment depends on the underlying cause, its timely finding being essential, since early onset impacts the patient's prognosis. We report the case of a patient who presented with atypical distribution paresthesias, neuropathic pain, and ataxia. The electrical study revealed a sensitive ganglionopathy, from whose etiological study arises the diagnosis of bronchopulmonary carcinoma.

Resumo: As ganglionopatias sensoriais são um grupo raro de neuropatias sensoriais que podem estar associadas a neoplasias como o câncer broncopulmonar. A apresentação clínica e o resultado do estudo elétrico são característicos. O tratamento depende da causa subjacente e seu achado oportuno é essencial, uma vez que o início precoce impacta o prognóstico do paciente. Relatamos o caso de um paciente que apresentou parestesias de distribuição atípica, dor neuropática e ataxia. O estudo elétrico revelou uma ganglionopatia sensível, de cujo estudo etiológico surge o diagnóstico de carcinoma broncopulmonar.

Transcriptional identification of genes light-interacting in the extraretinal photoreceptors of the crayfish Procambarusclarkii.

Crayfish serve as a model for studying the effect of environmental lighting on locomotor activity and neuroendocrine functions. The effects of light on this organism are mediated differentially by retinal and extraretinal photoreceptors located in the cerebroid ganglion and the pleonal nerve cord. However, some molecular aspects of the phototransduction cascade in the pleonal extraretinal photoreceptors remain unknown. In this study, transcriptome data from the pleonal nerve cord of the crayfish Procambarusclarkii (Girard,1852) were analyzed to identify transcripts that potentially interact with phototransduction process. The Illumina MiSeq System and the pipeline Phylogenetically Informed Annotation (PIA) were employed, which places uncharacterized genes into pre-calculated phylogenies of gene families. Here, for the first time 62 transcripts identified from the pleonal nerve cord that are related to light-interacting pathways are reported; they can be classified into the following 11 sets: 1) retinoid pathway in vertebrates and invertebrates, 2) photoreceptor specification, 3) rhabdomeric phototransduction, 4) opsins 5) ciliary phototransduction, 6) melanin synthesis, 7) pterin synthesis, 8) ommochrome synthesis, 9) heme synthesis, 10) diurnal clock, and 11) crystallins. Moreover, this analysis comparing the sequences located on the pleonal nerve cord to eyestalk sequences reported in other studies reveals 94-100% similarity between the 55 common proteins identified. These results show that both retinal and pleonal non-visual photoreceptors in the crayfish equally expressed the transcripts involved in light detection. Moreover, they suggest that the genes related to ocular and extraocular light perception in the crayfish P.clarkii use biosynthesis pathways and phototransduction cascades commons.

Predictive value of blood measurement of Complement System proteins and metabolic components for early detection of obstetric complications linked to poor placental function.

Preeclampsia-eclampsia syndrome (PES) is associated with severe obstetric complications and there are no efficient methods available for an early detection. We studied blood concentration of some immunological and metabolic markers in association with obstetric outcome in healthy pregnant women and patients with obstetric risk factors, by ELISA and biochemical tests. Patients with complications showed higher levels of CRP and C4 positively correlated with Triglycerides and Cholesterol concentrations. Our results provide evidence that Immunological and metabolic alterations contribute to obstetric complications and that biomarkers linked to these alterations could be useful for an early detection of these problems.

Hemofilia adquirida. Presentación de caso clínico y revisión de la bibliografía / Acquired hemophilia. Presentation of clinical case and review of the bibliography / Hemofilia adquirida. Apresentação de caso clínico e revisão da bibliografia

Resumen. La hemofilia adquirida es un trastorno de la coagulación poco frecuente causado por autoanticuerpos circulantes que inhiben factores de la coagulación, principalmente el F VIII. Un porcentaje considerable de pacientes con hemofilia adquirida mueren a causa de un diagnóstico tardío con el consecuente retraso en el inicio del tratamiento. Los objetivos principales del tratamiento son controlar el sangrado, erradicar el inhibidor y tratar los trastornos subyacentes que se logren identificar. Presentamos el caso de una mujer de 72 años con el antecedente de una artritis reumatoidea que se presentó con un síndrome hemorragíparo de tipo coagulopático de aparición espontánea.

Abstract. Acquired hemophilia is a rare coagulation disorder caused by circulating autoantibodies that inhibit coagulation factors, primarily F VIII. A considerable percentage of patients with acquired hemophilia die due to a late diagnosis with the consequent delay in the start of treatment. The main goals of treatment are to control bleeding, eradicate the inhibitor and treat underlying disorders that can be identified. We present the case of a 72-year-old woman with a history of rheumatoid arthritis who presented with a coagulopathic hemorrhagic syndrome of spontaneous onset.

Resumo. A hemofilia adquirida é um distúrbio raro da coagulação causado por autoanticorpos circulantes que inibem fatores de coagulação, principalmente F VIII. Uma porcentagem considerável de pacientes com hemofilia adquirida morre devido a um diagnóstico tardio com o consequente atraso no início do tratamento. Os principais objetivos do tratamento são controlar o sangramento, erradicar o inibidor e tratar os distúrbios subjacentes que podem ser identificados. Apresentamos o caso de uma mulher de 72 anos com história de artrite reumatoide que apresentou síndrome hemorrágica coagulopática de início espontâneo.

Transcriptional Identification of Related Proteins in the Immune System of the Crayfish Procambarus clarkii.

The freshwater crayfish Procambarus clarkii is an animal model employed for physiological and immunological studies and is also of great economic importance in aquaculture. Although it is a species of easy husbandry, a high percentage of its production is lost annually as a result of infectious diseases. Currently, genetic information about the immune system of crustaceans is limited. Therefore, we used the abdominal nerve cord from P. clarkii to obtain its transcriptome using Next Generation Sequencing (NGS) to identify proteins that participate in the immune system. The reads were assembled de novo and consensus sequences with more than 3000 nucleotides were selected for analysis. The transcripts of the sequences of RNA were edited for annotation and sent to the GenBank database of the National Center for Biotechnology Information (NCBI). We made a list of accession numbers of the sequences which were organized by the putative role of the immune system pathway in which they participate. In this work, we report on 80 proteins identified from the transcriptome of crayfish related to the immune system, 74 of them being the first reported for P. clarkii. We hope that the knowledge of these sequences will contribute significantly to the development of future studies of the immune system in crustaceans.

Compliance with the 2009 Royal College of Obstetricians and Gynaecologists guidelines for venous thromboembolic disease prophylaxis in pregnancy and postpartum period in Uruguay.

: Venous thromboembolism remains as one of the leading causes of maternal death. Prevention of venous thromboembolism in the obstetric population is challenging as recommendations for prophylaxis have low grade of evidence. Risk factors and prophylaxis guidelines have been highlighted by Royal College of Obstetricians and Gynaecologists. In 2014, we developed a written alert following this guidelines to guide thromboprophylaxis. The aim of this study is to assess recommendations compliance. This study was conducted at University-Hospital in Uruguay from January 2014 to December 2016. A total of 1035 women were enrolled and stratified in high, intermediate or low risk based on Royal College of Obstetricians and Gynaecologists guidelines. Thromboprophylaxis was recommended for women at intermediate and high risk. Women were followed up to assess symptomatic thromboembolism or haemorrhagic complications. A total of 309 were pregnant and 731 puerperal. Median age was 24 (19-29) years old. Of them, 3.0% (n = 31) were at high risk and 35.4% (n = 366) at intermediate risk. All high-risk women received prophylaxis with low-molecular-weight heparin. Of the 366 intermediate-risk women, 52.7% received prophylaxis. Venous thromboembolism was developed in only one woman of the intermediate group, who had received prophylaxis. Bleeding complications were not observed. Awareness of the thrombotic risk, as conferred by an easy and suitable risk assessment, has the potential to improve venous thromboembolism prophylaxis in pregnant and puerperal women. We have a good guidelines compliance with the written alert in the high-risk women group. However, we have to improve low-molecular-weight heparin indication in intermediate-risk group, especially in postcaesarean women.

Left-right asymmetry in firing rate of extra-retinal photosensitive neurons in the crayfish.

The purpose of this paper is to explore the firing rate of the caudal photoreceptors (CPRs) from the sixth abdominal ganglion of the crayfish Cherax quadricarinatus. We use simultaneous extracellular recordings on left and right CPR in the isolated ganglion (n = 10). The CPRs showed an asymmetry in the spontaneous activity and light-induced response. In darkness, we observed one subgroup (70%) in which the left CPR (CPR-L) and right CPR (CPR-R) had spontaneous firing rates with a median of 18 impulses/s and 6 impulses/s, respectively. In another subgroup (20%), the CPR-R had a median of 15 impulses/s and the CPR-L had 8 impulses/s. In both groups, the differences were significant. Furthermore, the CPRs showed an asymmetrical photoresponse induced by a pulse of white light (700 Lux, 4 s). In one subgroup (30%), the CPR-L showed light-induced activity with a median of 73%, (interquartile range, IQR = 51), while the CPR-R had a median of 41%, (IQR = 47). In another subgroup (70%), the CPR-R showed a median of 56%, (IQR = 51) and the CPR-L had a median of 42%, (IQR = 46). In both groups, the differences were significant. Moreover, we observed a differential effect of temperature on CPR activity. These results suggest a functional asymmetry in both activities from left and right CPRs. These CPR activity fluctuations may modulate the processing of information by the nervous system.

Síndrome hemofagocítico: una rara complicación en el paciente con infección por el virus de inmunodeficiencia humana (VIH) / Hemophagocytic syndrome: a rare complication in patients with human immunodeficiency virus (HIV) infection

Resumen: El síndrome hemofagocítico es una enfermedad infrecuente y grave caracterizada por un estado de hiperinflamación sistémica con sobreproducción de citocinas. Puede responder a causas genéticas (primario) o desencadenarse por infecciones, fármacos, neoplasias o enfermedades autoinmunes. Existen criterios diagnósticos establecidos. El tratamiento consiste en el bloqueo de la respuesta inflamatoria sistémica, asociado al tratamiento de la causa desencadenante cuando se halla. La mortalidad es alta y usualmente está en relación a la causa que gatilla el fenómeno. Se presenta un caso de sindrome hemofagocítico en paciente infectada por el virus de la inmunodeficiencia humana.

Abstract: Hemophagocytic syndrome is a rare and serious disease characterized by a state of systemic hyperinflammation with overproduction of cytokines. Can respond to genetic causes (primary) or be triggered by infections, drugs, tumors or autoimmune diseases. There are established diagnostic criteria. Treatment consists in blocking the inflammatory response associated with the treatment of the underlying cause when it is. Mortality is high and usually is related to the cause that triggers the phenomenon. We report a case of hemophagocytic syndrome in HIV-infected patient.

Octopamine cyclic release and its modulation of visual sensitivity in crayfish.

The biogenic amine octopamine (OA) modulates invertebrate behavior by changing neuronal responses from sensory inputs to motor outputs. However, the OA modulation of visual sensitivity and its possible coupling to diurnal cycles remains unexplored. Here we studied the diurnal variations in the OA levels in the hemolymph of the crayfish Procambarus clarkii, its release from the structures in the eyestalk and its modulation of the retinal light sensitivity. The hemolymph concentration of OA and its amino acid precursor tyrosine was measured by high-resolution liquid chromatography; OA varied along the 24-hcycle. The peak value appeared about 2h before the light offset which preceded the peak locomotor activity. OA was found in every structure of the eyestalk but displayed higher levels in the retina-lamina ganglionaris. Moreover, OA was released from isolated eyestalks at a rate of 92nmol/eyestalk/min and a calcium-dependent release was evoked by incubation in a high potassium solution. OA injected into dark-adapted crayfish or applied to the isolated retina at concentrations of 1, 10 and 100µM produced a proportionally increasing reduction in the amplitude of the photoreceptor light responses. These OA concentrations did not affect the position of the visual accessory pigments. Our results suggest that OA release in the crayfish eyestalk is coupled to the 24-hcycle to regulate the diurnal reduction of the photoreceptor sensitivity and to favor the expression of exploratory locomotion during the dark phase of the circadian cycle.

La Hipertensión Arterial es factor de riesgo para el desarrollo y progresión de la Enfermedad Renal Crónica / Arterial Hypertension is a risk factor for the development and progression of Chronic Kidney Disease

RESUMEN El vínculo entre Hipertensión Arterial (HTA) y Enfermedad Renal Crónica (ERC) es recíproco y complejo. La HTA es un factor de riesgo reconocido para el desarrollo de ERC, y la incidencia de enfermedad renal se incrementa conforme aumenta la severidad de la HTA. Adicionalmente la presencia de HTA se vincula a progresión de la ERC desde etapas tempranas hasta el desarrollo de ERC-extrema. La presencia de HTA enmascarada, HTA de túnica blanca y la pérdida del patrón dipping nocturno se vinculan a desarrollo y progresión de enfermedad renal. El tamizaje de ERC es recomendado para pacientes con HTA en riesgo de desarrollar la enfermedad. Es más discutido si debe realizarse tamizaje en individuos con bajo riesgo de desarrollar ERC. Las cifras objetivo de presión arterial en este grupo de pacientes son sugeridas por las guías KDIGO. Múltiples estudios han buscado identificar si el control intensivo de presión arterial disminuye la incidencia de ERC y su progresión pero los resultados no son concluyentes. El presente trabajo revisa el vínculo entre HTA y desarrollo y progresión de la ERC. Se puntualiza sobre la población con HTA que se beneficia del tamizaje de ERC y los valores objetivo de presión arterial en este grupo.

ABSTRACT The link between Arterial Hypertension (AHT) and Chronic Renal Disease (CKD) is reciprocal and complex. HBP is a recognized risk factor for the development of CKD, and the incidence of renal disease increases as the severity of hypertension increases. Additionally, the presence of hypertension is linked to progression of CKD from early stages to the development of extreme-ERC. The presence of masked HTA, white tunica HTA and loss of nocturnal dipping pattern are associated with development and progression of renal disease. Screening for CKD is recommended for patients with hypertension at risk of developing the disease. It is more controversial whether screening should be done in individuals at low risk of developing CKD. The target blood pressure figures in this group of patients are suggested by the KDIGO guidelines. Multiple studies have sought to identify whether intensive blood pressure control decreases the incidence of CKD and its progression but the results are inconclusive. This paper reviews the link between hypertension and development and progression of CKD. It is pointed out the population with hypertension that benefits from CKD screening and target blood pressure values ​​in this group.

Dengue en adultos: diagnóstico, tratamiento y abordaje de situaciones especiales / Dengue fever in adults: diagnosis, treatment and approach to special situations

El virus dengue pertenece a la familia Flaviviridae, es transmitido entre humanos en general por mosquitos del género Aedes. Uruguay estuvo libre de la enfermedad de adquisición autóctona en los últimos 100 años. En febrero del año 2016 se produjo la confirmación de los primeros casos autóctonos en Montevideo y con ello evidencia de un brote local. El objetivo de este trabajo es revisar los aspectos prácticos del manejo clínico de los pacientes con dengue presuntivo o confirmado, contribuyendo así a la discusión del tema y a la formación del equipo de salud en nuestro país. Se revisan desde un punto de vista práctico los aspectos clínicos de presentación de la infección, clasificación, diagnóstico de laboratorio, manejo inicial, y situaciones especiales como embarazo y comorbilidades.

Abstract Dengue virus belongs to the Flaviviridae family and is transmitted among humans by the bite of an Aedes mosquitoes. Uruguay had been free of this autochthonous disease in the last 100 years. In February 2016 the first autochthonous cases were confirmed in Montevideo, and this was the evidence for a local outbreak. This study aims to review practical aspects of the clinical handling of patients with dengue fever, whether presumed or conformed, thus contributing to the discussion of this issue and training the health team in our country. The infection’s clinical manifestation is reviewed in a practical, as well as its classification, laboratory diagnosis, initial handling and special situations such as pregnancy and comorbilities.

Resumo O vírus do dengue pertence à família Flaviviridae, e de maneira geral é transmitido entre humanos por mosquitos do gênero Aedes. Durante os últimos cem anos o Uruguay esteve livre de casos de dengue por infecção autóctone. Em fevereiro de 2016 os primeiros casos autóctones foram confirmados em Montevidéu e também a existência de um surto local. O objetivo deste trabalho é fazer uma revisão dos aspectos práticos do manejo clínico dos pacientes com suspeita de dengue ou com doença confirmada, contribuindo para a discussão do tema e para a formação da equipe de saúde no nosso país. Os aspectos clínicos da infecção, sua classificação, diagnóstico laboratorial, primeiras medidas e circunstâncias especiais como gravidez e outras patológicas concomitantes são discutidos.

Endocarditis infecciosa por Erysipelothrix rhusiopathiae: Report of one case / Infective endocarditis caused by Erysipelothrix rhusiopathie

Erysipelothrix rhusiopathie is an immobile, not sporulated, gram positive bacillus. Man is an accidental host. Infection is acquired through wounds on contact with sick animals or carriers, their products or objects contaminated with their waste. We report a 40 years old tannery male worker, presenting in the emergency room with fever lasting one month. An echocardiogram showed a vegetation and perforation of the aortic valve with severe aortic regurgitation. Blood cultures gave growth to E. rhusiopathiae. The patient was treated with penicillin. After three weeks of treatment an aortic valve replacement with a mechanical valve was performed. At six weeks, he was discharged from the hospital.

Hiponatremia severa e hidrocefalia normotensiva del adulto: Reporte de un caso / Severe hyponatremia and normotensive hydrocephalus in the adult: Report of a case

Presentamos una paciente de 62 años de edad que ingresa por cefalea, alteraciones conductuales, síndrome tónico-frontal simétrico y síndrome cerebeloso de dos meses de evolución asociado a hiponatremia crónica severa. Se plantea el diagnóstico de síndrome de secreción inadecuada de hormona antidiurética (ADH) secundario a hidrocefalia normotensiva del adulto, presentando clara mejoría con la derivación ventrículo-peritoneal. Este caso pretende aportar información sobre una asociación descrita pero poco frecuente.

We present a 62-year-old patient presenting with a two-month episode of headaches, disrupted behavior, symmetric tonic frontal syndrome and cerebellar syndrome associated with severe chronic hyponaetremia. The diagnosis upon admission was an inadequate anti-diuretic hormone (ADH) secretion syndrome secondary to normotensive hydrocephalus of the adult, clearly improving after the ventricular-peritoneal shunt. This case provides information on a rarely reported association.

[Infective endocarditis caused by Erysipelothrix rhusiopathie. Report of one case]. / Endocarditis infecciosa por Erysipelothrix rhusiopathiae.

Erysipelothrix rhusiopathie is an immobile, not sporulated, gram positive bacillus. Man is an accidental host. Infection is acquired through wounds on contact with sick animals or carriers, their products or objects contaminated with their waste. We report a 40 years old tannery male worker, presenting in the emergency room with fever lasting one month. An echocardiogram showed a vegetation and perforation of the aortic valve with severe aortic regurgitation. Blood cultures gave growth to E. rhusiopathiae. The patient was treated with penicillin. After three weeks of treatment an aortic valve replacement with a mechanical valve was performed. At six weeks, he was discharged from the hospital.

Espondilodiscitis a germen inusual: análisis de un caso clínico y revisión de la bibliografía / Spondilodiscitis caused be an unusual organism: clinical case report and literature review

La espondilodiscitis infecciosa es una entidad poco frecuente que afecta el disco intervertebral y las vértebras adyacentes. Su importancia clínica radica en la morbilidad que determina. En este caso nos centraremos en la espondilodiscitis piógena (EP) y, dentro de ella, en la estreptocócica. Se presenta el caso clínico de un paciente con espondilodiscitis por Streptoccocus intermedius perteneciente al grupo viridans, se analizan las características clínicas, y se realiza una breve revisión bibliográfica.

Infectious spondylodiscitis is a rare condition that affects the intervertebral disc and adjacent vertebrae. Its clinical relevance is related with its morbidity. In this case we will focus on the pyogenous spondylodiscitis (PS), and more specifically, streptococcal. Clinical case report of a patient with spondylodiscitis caused by Streptoccocus intermedius of the viridans group, with a description of the clinical features and a brief literature review.

Estados hipertensivos del embarazo

Resumen Los estados hipertensivos del embarazo constituyen una de las principales causas de morbimortalidad materno-fetal y son la principal causa de muerte materna en muchos países desarrollados. Si bien ha habido un notable avance en su comprensión y una mejora en los resultados aún quedan aspectos por dilucidar y la condición de gestantes impone desafíos metodológicos y bioéticos que dificultan la generación de evidencias de buena calidad. En este artículo se repasan algunas de las modificaciones fisiológicas y de acuerdo a la clasificación más aceptada se enfatiza y se centra la revisión en la hipertensión arterial crónica. Se analiza su posible subdiagnóstico, la repercusión materna y obstétrica y se discute el umbral a partir del cual se debe iniciar tratamiento farmacológico. Se hacen recomendaciones para su manejo diagnóstico y terapéutico tanto farmacológico como no farmacológico de acuerdo a la mejor evidencia disponible. Se analizan brevemente los fármacos de mayor uso y seguridad así como aquellos que son controversiales o están formalmente contraindicados durante el embarazo y/o la lactancia. Finalmente se abordan sucintamente la hipertensión gestacional, la hipertensión posparto y la hipertensión severa así como la preeclampsia sobreagregada, haciéndose hincapié en la discusión y recomendaciones acerca de la posible prevención de esta última entidad.

Variations in interpulse interval of double action potentials during propagation in single neurons.

In this work, we analyzed the interpulse interval (IPI) of doublets and triplets in single neurons of three biological models. Pulse trains with two or three spikes originate from the process of sensory mechanotransduction in neurons of the locust femoral nerve, as well as through spontaneous activity both in the abdominal motor neurons and the caudal photoreceptor of the crayfish. We show that the IPI for successive low-frequency single action potentials, as recorded with two electrodes at two different points along a nerve axon, remains constant. On the other hand, IPI in doublets either remains constant, increases or decreases by up to about 3 ms as the pair propagates. When IPI increases, the succeeding pulse travels at a slower speed than the preceding one. When IPI is reduced, the succeeding pulse travels faster than the preceding one and may exceed the normal value for the specific neuron. In both cases, IPI increase and reduction, the speed of the preceding pulse differs slightly from the normal value, therefore the two pulses travel at different speeds in the same nerve axon. On the basis of our results, we may state that the effect of attraction or repulsion in doublets suggests a tendency of the spikes to reach a stable configuration. We strongly suggest that the change in IPI during spike propagation of doublets opens up a whole new realm of possibilities for neural coding and may have major implications for understanding information processing in nervous systems.