238 research outputs found

    Manifestaciones neurológicas de la infección por el virus zika

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    Zika virus is a flavivirus transmitted via mosquito bite, blood transfusion, sexual intercourse or from mother-to-child during gestation. Although neurologic complications of Zika virus infection are rare, Guillain-Barré syndrome (GBS) is the most common manifestation and typically develops soon after the initial systemic manifestations of Zika virus infection. This syndrome typically starts in the distal limbs with symmetric sensory abnormalities and progresses to involve weakness and decreased or absent deep tendon reflexes. Severe cases may also involve respiratory and cardiovascular impairment requiring care in an intensive care unit, and ventilator or circulatory support. A review of 166 published cases of GBS associated with Zika virus is notable for lower mortality than seen with sporadic GBS, but limited data regarding long-term outcome. When available, treatment with intravenous IgG (IVIg) or plasmapheresis, can reduce the severity and duration of symptoms.El virus zika es un flavivirus transmitido a través de la mordedura de mosquito, transfusión de sangre, la relación sexual o de madre a hijo durante la gestación. Aunque las complicaciones neurológicas de la infección por el virus zika son raras, el síndrome de Guillain-Barré (GBS) es la manifestación más común y normalmente se desarrolla poco después de las manifestaciones sistémicas iniciales de la infección por el virus. Este síndrome comienza en las extremidades distales con alteraciones sensoriales simétricas y progresa hasta involucrar la debilidad y la disminución o ausencia de reflejos tendinosos profundos. Los casos graves pueden implicar deterioro respiratorio y cardiovascular, requiriendo atención en una unidad de cuidados intensivos, así como ventilador o soporte circulatorio. Una revisión de 166 casos publicados de GBS asociados con el virus zika se caracteriza por una menor mortalidad que los observados con GBS esporádica, pero los datos son limitados con respecto a resultados a largo plazo. Cuando esté disponible, el tratamiento con IgG intravenoso (IVIg) o plasmaféresis puede reducir la gravedad y duración de los síntomas

    Oral epithelial expression of angiotensin converting enzyme-2: Implications for COVID-19 diagnosis and prognosis

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    The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) uses the angiotensin converting enzyme (ACE)-2 as the host receptor for target cell entry. The extent and distribution of ACE-2 has been associated with the clinical symptoms of coronavirus disease (COVID)-19. Here we show by immunofluorescence analysis that the ACE2 is abundantly expressed in oral mucosa, particularly in the surface epithelial cells suggesting that these cells could represent sites of entry for SARS-CoV-2. Further, together with the reports on ACE2 ectodomain shedding, we discuss the rationale for the hypothesis that the ACE-2 measurement in saliva could be a marker for COVID-19 infection during early phase following SARS-CoV-2 exposure

    Algorithms for adaptive frequency hopping spread spectrum systems

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    Tato diplomová práce pojednává o systémech, které využívají techniku frekvenčního skákání FH (Frequency Hopping). Je vysvětlen princip této techniky a její výhody a nevýhody. Následuje popis techniky adaptivního frekvenčního skákání AFH (Adaptive Frequency Hopping), kterou využívá systém Bluetooth. Následuje popis dalších metod na úpravu skokové posloupnosti jako například dynamické frekvenční skákání DFH (Dynamic Frequency Hopping), které využívá standart 802.22. Tento standart se zabývá použitím části spektra, které dosud využívá TV vysílání (47–910 MHz) pro použití ve WRAN (Wireless Regional Area Network). Další technika úpravy skokové posloupnosti se jmenuje adaptivní rotace nosných frekvencí AFR (Adaptive Frequency Rolling). Rotace nosných tvz. „rolling“ je nová technika umožňující více pikosítím, které by se normálně vzájemně ovlivňovaly využívat stejné kanály v různých časových úsecích. Poslední technika, která je v práci představena se jmenuje dynamické adaptivní frekvenční skákání nosné DAFH (Dynamic Adaptive Frequency Hopping). Tato technika taktéž řeší vzájemné ovlivňování více pikosítí pomocí zmenšování nebo zvětšování skokové posloupnosti. Praktická část diplomové práce popisuje návrh modelu AFH systému za pomocí programu Matlab Simulink. V práci jsou popsány funkce jednotlivých bloků a jejich nastavení. Dále je uveden popis grafického rozhraní pomocí, kterého můžeme jednoduše měnit parametry simulace. Výsledný model dokáže simulovat vliv statických a dynamických růšiču v přenosovém pásmu při komunikaci dvou zařízení.This master's thesis deal the system, which use the Frequency Hopping (FH). Is explained principle those techniques and her benefits and disadvantages. Follows description techniques Adaptive Frequency Hopping (AFH) that used the Bluetooth. Follows description other method for setup hopset such as Dynamic Frequency Hopping (DFH), which used standards 802.22. 22. Is an emerging standard for Wireless Regional Area Networks (WRAN) operating on a license-exempt and non-interference basis in the spectrum allocated to TV broadcast services (between 47–910 MHz). Other method introduces the Adaptive Frequency Rolling (AFR), a particular instance of frequency hopping (FH) that enables the collocated WPANs to cooperate and avoid the self-interference. The AFR uses as input solely the observed packet error rate (PER) and it does not require any exchange of information among the collocated WPANs. The effect of the FR over a longer time interval is that the WPANs use the complete set of disposable channels in an implicit time-division and cooperative manner. Last method described in this Thesis is Dynamic Adaptive Frequency Hopping (DAFH). The basic strategy applied in DAFH is a binary search for a hopset that offers smaller PER. The set of admissible hopsets depends on the total number of available channels and the maximal level of binary divisions. Practical part of the master's thesis describes proposal model AFH, with usage of Matlab Simulink programme. In thesis are described function each blocks a their setting. Simulation parameters can change in simple graphic interface. The model is able to simulate influence of static and dynamic interference in transmission band of two communicating devices.

    Clinical research training of Peruvian neurologists: a baseline assessment

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    In Peru, despite a strong clinical research infrastructure in Lima, and Masters degree programs in epidemiology at three universities, few neurologists participate in clinical research. It was our objective to identify perceived needs and opportunities for increasing clinical research capacity and training opportunities for Peruvian neurologists. We conducted a descriptive, cross-sectional survey of Peruvian neurologists in Lima and Arequipa, Peru. Forty-eight neurologists completed written surveys and oral interviews. All neurologists reported interest in clinical research, but noted that lack of time and financial resources limited their ability to participate. Although most neurologists had received some training in epidemiology and research design as medical students or residents, the majority felt these topics were not adequately covered. Neurologists in Arequipa noted international funding for clinical research was uncommon outside the capital city of Lima. We concluded that clinical research is important to Peruvian neurologists. The three main barriers to increased participation in clinical research identified by neurologists were insufficient training in clinical research methodology, meager funding opportunities, and lack of dedicated time to participate in clinical research. Distance learning holds promise as a method for providing additional training in clinical research methodology, especially for neurologists who may have difficulty traveling to larger cities for additional training

    Tuberculosis of the Central Nervous System in Immunocompromised Patients: HIV Infection and Solid Organ Transplant Recipients

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    Central nervous system (CNS) tuberculosis (TB) is a devastating infection with high rates of morbidity and mortality worldwide and may manifest as meningitis, tuberculoma, abscess, or other forms of disease. Immunosuppression, due to either human immunodeficiency virus infection or solid organ transplantation, increases susceptibility for acquiring or reactivating TB and complicates the management of underlying immunosuppression and CNS TB infection. This article reviews how immunosuppression alters the clinical presentation, diagnosis, treatment, and outcome of TB infections of the CNS

    Global research priorities for infections that affect the nervous system

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    Infections that cause significant nervous system morbidity globally include viral (for example, HIV, rabies, Japanese encephalitis virus, herpes simplex virus, varicella zoster virus, cytomegalovirus, dengue virus and chikungunya virus), bacterial (for example, tuberculosis, syphilis, bacterial meningitis and sepsis), fungal (for example, cryptococcal meningitis) and parasitic (for example, malaria, neurocysticercosis, neuroschistosomiasis and soil-transmitted helminths) infections. The neurological, cognitive, behavioural or mental health problems caused by the infections probably affect millions of children and adults in low- and middle-income countries. However, precise estimates of morbidity are lacking for most infections, and there is limited information on the pathogenesis of nervous system injury in these infections. Key research priorities for infection-related nervous system morbidity include accurate estimates of disease burden; point-of-care assays for infection diagnosis; improved tools for the assessment of neurological, cognitive and mental health impairment; vaccines and other interventions for preventing infections; improved understanding of the pathogenesis of nervous system disease in these infections; more effective methods to treat and prevent nervous system sequelae; operations research to implement known effective interventions; and improved methods of rehabilitation. Research in these areas, accompanied by efforts to implement promising technologies and therapies, could substantially decrease the morbidity and mortality of infections affecting the nervous system in low- and middle-income countries
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