ZYG-9ch-TOG promotes the stability of acentrosomal poles via regulation of spindle microtubules in C. elegans oocyte meiosis.

During mitosis, centrosomes serve as microtubule organizing centers that guide the formation of a bipolar spindle. However, oocytes of many species lack centrosomes; how meiotic spindles establish and maintain these acentrosomal poles remains poorly understood. Here, we show that the microtubule polymerase ZYG-9ch-TOG is required to maintain acentrosomal pole integrity in C. elegans oocyte meiosis. We exploited the auxin inducible degradation system to remove ZYG-9 from pre-formed spindles within minutes; this caused the poles to split apart and an unstable multipolar structure to form. Depletion of TAC-1, a protein known to interact with ZYG-9 in mitosis, caused loss of proper ZYG-9 localization and similar spindle phenotypes, further demonstrating that ZYG-9 is required for pole integrity. However, depletion of ZYG-9 or TAC-1 surprisingly did not affect the assembly or stability of monopolar spindles, suggesting that these proteins are not required for acentrosomal pole structure per se. Moreover, fluorescence recovery after photobleaching (FRAP) revealed that ZYG-9 turns over rapidly at acentrosomal poles, displaying similar turnover dynamics to tubulin itself, suggesting that ZYG-9 does not play a static structural role at poles. Together, these data support a global role for ZYG-9 in regulating the stability of bipolar spindles and demonstrate that the maintenance of acentrosomal poles requires factors beyond those acting to organize the pole structure itself.

Multiple motors cooperate to establish and maintain acentrosomal spindle bipolarity in C. elegans oocyte meiosis.

While centrosomes organize spindle poles during mitosis, oocyte meiosis can occur in their absence. Spindles in human oocytes frequently fail to maintain bipolarity and consequently undergo chromosome segregation errors, making it important to understand the mechanisms that promote acentrosomal spindle stability. To this end, we have optimized the auxin-inducible degron system in Caenorhabditis elegans to remove the factors from pre-formed oocyte spindles within minutes and assess the effects on spindle structure. This approach revealed that dynein is required to maintain the integrity of acentrosomal poles; removal of dynein from bipolar spindles caused pole splaying, and when coupled with a monopolar spindle induced by depletion of the kinesin-12 motor KLP-18, dynein depletion led to a complete dissolution of the monopole. Surprisingly, we went on to discover that following monopole disruption, individual chromosomes were able to reorganize local microtubules and re-establish a miniature bipolar spindle that mediated chromosome segregation. This revealed the existence of redundant microtubule sorting forces that are undetectable when KLP-18 and dynein are active. We found that the kinesin-5 family motor BMK-1 provides this force, uncovering the first evidence that kinesin-5 contributes to C. elegans meiotic spindle organization. Altogether, our studies have revealed how multiple motors are working synchronously to establish and maintain bipolarity in the absence of centrosomes.

Meiosis is a specialized form of cell division that produces the gametes required for sexual reproduction, such as egg and sperm cells. Before the cell splits, it copies its genome so that it has four sets of chromosomes. Genetic information is then shuffled between the chromosomes, and the cell undergoes two rounds of division, resulting in four gametes that are genetically distinct. Prior to division, the duplicated chromosomes are separated by rope-like protein polymers called microtubules. In most cells, structures called centrosomes organize these fibers into a spindle shape that emanates from two 'poles' on opposite ends of the cell: the microtubules then attach to the chromosomes and pull them apart. Despite not having centrosomes, egg cells, or 'oocytes', are still able to arrange their microtubules into a similar bipolar shape. However, how oocytes form these 'acentrosomal' spindles is poorly understood. Centrosomes do not organize the spindle alone, and receive help from various motor proteins such as dynein. Previous work showed that dynein is involved in arranging acentrosomal poles, but it was not known if it was required to hold the poles together after they initially formed. To investigate, Cavin-Meza et al. developed a strategy that can rapidly remove dynein from oocytes of the roundworm Caenorhabditis elegans. The experiment showed that dynein is required both to assemble and stabilize acentrosomal spindles in C. elegans. When dynein and an additional motor protein, KLP-18, were both removed from oocytes simultaneously, the poles blew apart, completely disrupting spindle organization. Surprisingly, Cavin-Meza et al. found that the spindles were able to reform and separate the chromosomes. Further probing revealed, for the first time, that a third motor protein (called BMK-1) also helps to organize the spindle into its bipolar structure. These findings reveal the important role motor proteins play in stabilizing spindles and separating chromosomes in oocytes. Meiosis is prone to mistakes, and these errors are a major cause of miscarriages and birth defects in humans. Therefore, understanding the underlying mechanisms of how oocyte spindles form and remain stable could shed light on why chromosomes sometimes fail to segregate. This may eventually lead to new strategies for combating infertility.

Miller Fisher syndrome treated with plasmapheresis during pregnancy: Case report and review of the literature / Síndrome de Miller Fisher tratado con plasmaféresis durante el embarazo: reporte de un caso y revisión de la literatura

Objective: To report the case of pregnant woman with Guillain-Barré syndrome (GBS) presenting as the Miller Fisher variant, and to review the literature on the diagnosis, treatment and prognosis of this GBS variant during gestation. Materials and Methods: Pregnant woman presenting at 27 weeks of gestation with Miller Fisher syndrome (MFS), treated in a military referral hospital with a satisfactory course after 15 days, continuation of normal pregnancy and delivery of a healthy neonate at 38 weeks. A search of the literature was conducted in the Medline via PubMed, Lilacs, SciELO, ScienceDirect and Ovid databases using the terms "Pregnancy," "Miller Fisher syndrome," "Guillain-Barré syndrome". Cohorts, case series and case reports of pregnant women with MFS were included. Data on diagnostic methods, treatment and maternal and perinatal prognosis were extracted. The search was made on June 2020, with no restriction by date, but restriction by language (Spanish and English). Results: Overall, 423 titles were identified, three studies met the inclusion criteria, the three of them corresponding to case reports. All cases were found to be seropositive for anti-GQ1b ganglioside antibodies. No imaging abnormalities were found in any of the cases. Two patients received IV immunoglobulin and the third patient was kept under observation. No obstetric complications have be documented so far. Conclusion: There are few cases of MFS reported during pregnancy. Intravenous immunoglobulin is the most frequently used treatment option. Plasmapheresis was used in the case presented here. The impact of the Miller Fisher variant on the normal course of gestation and on long-term perinatal outcomes is unknown. Further studies that look into the diagnosis, treatment and prognosis of this condition are required.

Objetivo: reportar el caso de una paciente gestante con síndrome de Guillain-Barré (SGB) presentado en la variante denominada síndrome de Miller Fisher (SMF), y realizar una revisión en torno al diagnóstico, tratamiento y pronóstico de esta variedad de SGB durante la gestación. Materiales y métodos: se presenta el caso de una gestante de 27 semanas con síndrome de Miller Fisher, quien fue tratada con plasmaféresis en un hospital militar de referencia, con evolución satisfactoria a los 15 días y continuación normal del embarazo, parto a las 38 semanas con recién nacido sano. Se realizó una búsqueda bibliográfica en bases de datos electrónicas: Medline vía PubMed, Lilacs, SciELO, ScienceDirect, Ovid, con los términos "Embarazo", "Síndrome de Miller Fisher", "Síndrome de Guillain-Barré". Se incluyeron cohortes, series y reportes de casos de mujeres gestantes con síndrome de Miller Fisher; se extrajo información sobre los métodos diagnósticos, el tratamiento utilizado y el pronóstico materno y perinatal. La búsqueda se hizo en junio de 2020, sin restricción por fecha, pero sí por tipo de idioma (español e inglés). Resultados: se identificaron 423 títulos, tres estudios cumplieron los criterios de inclusión, los tres correspondieron a reportes de caso. Todos los casos mostraron seropositividad para antigangliósidos GQ1b positivos; en ningún caso hubo alteración imagenológica. Dos pacientes recibieron inmunoglobulina intravenosa y la tercera paciente se dejó en observación. Hasta el momento no se documentan complicaciones obstétricas. Conclusión: existen pocos casos reportados de SMF durante la gestación, el diagnóstico se basa en el examen clínico; el tratamiento con inmunoglobulina IV representa la alternativa utilizada con mayor frecuencia. En el caso presentado se utilizó la plasmaféresis. Se desconoce el impacto de la variedad del síndrome de Miller Fisher sobre el curso normal de la gestación y sobre los resultados perinatales a largo plazo. Se requieren más estudios que aborden el diagnóstico, el tratamiento y el pronóstico de esta entidad.

Síndrome de Miller Fisher tratado con plasmaféresis durante el embarazo: reporte de un caso y revisión de la literatura / Miller Fisher syndrome treated with plasmapheresis during pregnancy: Case report and review of the literature

Resumen Objetivo: Reportar el caso de una paciente gestante con síndrome de Guillain-Barré (SGB) presentado en la variante denominada síndrome de Miller Fisher (SMF), y realizar una revisión en torno al diagnóstico, tratamiento y pronóstico de esta variedad de SGB durante la gestación. Materiales y métodos: Se presenta el caso de una gestante de 27 semanas con síndrome de Miller Fisher, quien fue tratada con plasmaféresis en un hospital militar de referencia, con evolución satisfactoria a los 15 días y continuación normal del embarazo, parto a las 38 semanas con recién nacido sano. Se realizó una búsqueda bibliográfica en bases de datos electrónicas: Medline vía PubMed, Lilacs, SciELO, ScienceDirect, Ovid, con los términos "Embarazo", "Síndrome de Miller Fisher", "Síndrome de Guillain-Barré". Se incluyeron cohortes, series y reportes de casos de mujeres gestantes con síndrome de Miller Fisher; se extrajo información sobre los métodos diagnósticos, el tratamiento utilizado y el pronóstico materno y perinatal. La búsqueda se hizo en junio de 2020, sin restricción por fecha, pero sí por tipo de idioma (español e inglés). Resultados: Se identificaron 423 títulos, tres estudios cumplieron los criterios de inclusión, los tres correspondieron a reportes de caso. Todos los casos mostraron seropositividad para antigangliósidos GQ1b positivos; en ningún caso hubo alteración imagenológica. Dos pacientes recibieron inmunoglobulina intravenosa y la tercera paciente se dejó en observación. Hasta el momento no se documentan complicaciones obstétricas. Conclusión: Existen pocos casos reportados de SMF durante la gestación, el diagnóstico se basa en el examen clínico; el tratamiento con inmunoglobulina IV representa la alternativa utilizada con mayor frecuencia. En el caso presentado se utilizó la plasmaféresis. Se desconoce el impacto de la variedad del síndrome de Miller Fisher sobre el curso normal de la gestación y sobre los resultados perinatales a largo plazo. Se requieren más estudios que aborden el diagnóstico, el tratamiento y el pronóstico de esta entidad.

Abstract Objective: To report the case of pregnant woman with Guillain-Barré syndrome (GBS) presenting as the Miller Fisher variant, and to review the literature on the diagnosis, treatment and prognosis of this GBS variant during gestation. Materials and Methods: Pregnant woman presenting at 27 weeks of gestation with Miller Fisher syndrome (MFS), treated in a military referral hospital with a satisfactory course after 15 days, continuation of normal pregnancy and delivery of a healthy neonate at 38 weeks. A search of the literature was conducted in the Medline via PubMed, Lilacs, SciELO, ScienceDirect and Ovid databases using the terms "Pregnancy," "Miller Fisher syndrome," "Guillain-Barré syndrome". Cohorts, case series and case reports of pregnant women with MFS were included. Data on diagnostic methods, treatment and maternal and perinatal prognosis were extracted. The search was made on June 2020, with no restriction by date, but restriction by language (Spanish and English). Results: Overall, 423 titles were identified, three studies met the inclusion criteria, the three of them corresponding to case reports. All cases were found to be seropositive for anti-GQ1b ganglioside antibodies. No imaging abnormalities were found in any of the cases. Two patients received IV immunoglobulin and the third patient was kept under observation. No obstetric complications have be documented so far. Conclusion: There are few cases of MFS reported during pregnancy. Intravenous immunoglobulin is the most frequently used treatment option. Plasmapheresis was used in the case presented here. The impact of the Miller Fisher variant on the normal course of gestation and on long-term perinatal outcomes is unknown. Further studies that look into the diagnosis, treatment and prognosis of this condition are required.

Enfoque holístico al paciente neurológico: el aporte de Oliver Sacks / Holistic approach to neurological patients: the Oliver Sacks's contribution

La obra de Oliver Sacks es bien conocida y muy destacada en la literatura de divulgación médica y ha contribuidoal conocimiento de la enfermedad neurológica por el público en general. Desde el punto de vista de laneurología literaria sus escritos han sido analizados por muchos autores. El presente artículo examina desdela perspectiva de un neurólogo clínico algunos elementos de la obra de Oliver Sacks que podrían ser de granbeneficio en el abordaje diagnóstico y terapéutico del paciente neurológico y un valioso aporte a la prácticaclínica de la neurología. Se exploran también algunas nuevas contribuciones hechas por la investigación enneurociencias y por la psicología cognitiva al abordaje holístico del paciente en medicina y se discuten losbeneficios de este abordaje en la recuperación de la enfermedad neurológica.

Oliver Sacks's work is well known and prominent in the medical literature for common people and has contributed to the understanding of neurological disease by the general public. Many authors from the point of view of literary neurology have analyzed his work. This article examines elements from the work of Oliver Sacks that could benefit the diagnosis approach and treatment of neurological patients and be a valuable contribution to the clinical practice of neurology from the perspective of a clinical neurologist. Some new contributions made by research in neuroscience and cognitive psychology to the holistic approach to the patient in medicine is also analyzed and the benefits of this approach in the recovery from neurological disease.

Explotación industrial de avestruces, emús y ñandúes / Industrial explotation of ostriches, emus and rheas

Es obvio que se trata de una industria en desarrollo con muchas interrogantes. El futuro criador debe informarse en detalle, especialmente sobre el mercado existente y la parte económica (inversión versus retorno). Esta y otra información referente a la crianza misma, construcciones, alimentos, etc., pueden obtener de los Departamentos de Aves y/o Ciencias Animales de distintas universidades, siendo esta misma la mejor opción por su imparcialidad y desinterés. Posteriormente se pueden contactar criaderos, Asociaciones de Productores, representantes de equipos, etc. pero ellos tienen interés en la industria.