Migration and differentiation of neuronal precursors in the postnatal brain: insights from the subventricular zone and cerebellum

Fundação para a Ciência e a Tecnologia - SFRH/BD/42848/2008, através do Programa MIT_Portugal em Sistemas de Bioengenharia; projectos PTDC/SAUNEU/104415/2008 e Projecto ref. 96542 da Fundação Caloust Gulbenkian

Hierarchical Reinforcement Learning in Behavior and the Brain

Dissertation presented to obtain the Ph.D degree in Biology, Neuroscience

UNCERTAINTY AND DECISION-MAKING IN THE HUMAN BRAIN

Dissertation presented to obtain the Ph.D degree in Biology, Neuroscience

Simultaneous occurrence of brain tumor and myeloradiculopathy in schistosomiasis mansoni: case report

Simultaneous occurrence of brain tumor and myeloradiculopathy in cases of Manson's schistosomiasis have only rarely been described. We report the case of a 38-year-old man who developed seizures during a trip to Puerto Rico and in whom a brain tumor was diagnosed by magnetic resonance imaging: brain biopsy revealed the diagnosis of schistosomiasis. He was transferred to a hospital in the United States and, during hospitalization, he developed sudden paraplegia. The diagnosis of myeloradiculopathy was confirmed at that time. He was administered praziquantel and steroids. The brain tumor disappeared, but the patient was left with paraplegia and fecal and urinary dysfunction. He has now been followed up in Brazil for one year, and his clinical state, imaging examinations and laboratory tests are presented here.

Injuries and envenoming by aquatic animals in fishermen of Coxim and Corumbá municipalities, state of Mato Grosso do Sul, Brazil: identification of the causative agents, clinical aspects and first aid measures

INTRODUCTION: The fishes of continental Brazil have socioeconomic importance due to their potential for sport fishing and commercial and subsistence uses, as seen in the Upper Paraguay River Basin, particularly in the municipalities of the Pantanal region, where it is the second largest economic activity. Injuries caused in professional fishermen are common and poorly studied, as in other regions of the country. METHODS: Data were obtained from questionnaires and interviews with 100 professional fishermen, 50 in each municipality, between December 2008 and October 2009. RESULTS: All the fishermen reported some kind of injury caused by fish stings (78% of injuries) and fish, alligator and snake bites (22%) on the hands (46% of cases) and feet (35% of cases). Most of the patients had mild symptoms. The most severe cases were associated with secondary bacterial infections and required specific treatment and prolonged recovery associated with social and economic losses. CONCLUSIONS: The results of this study indicate that the stressful work conditions, inattention to basic preventive measures and carelessness were factors that contributed to accidents and that the toxicity and ability to inflict mechanical trauma of some aquatic species, plus the ineffective use of first aid and hospital treatment, contributed to the high morbidity and complications in many cases. Data from this study are relevant to the fishing communities of the Pantanal region, since they reveal high rates of accidents, lack of knowledge concerning first aid, initial treatment, injury prevention and lack of medical follow-up of the population.

Observation of initial clinical manifestations and repercussions from the treatment of 314 human injuries caused by black sea urchins (Echinometra lucunter) on the southeastern Brazilian coast

INTRODUCTION: Injuries caused by sea urchins are the most common caused by marine animals in humans in Brazil, with the black sea urchin (Echinometra lucunter) causing the most injuries to bathers. METHODS: This study observed 314 human wounds with emphasis on the early observation of clinical signs and symptoms and their implications on the recommended treatment. RESULTS: All the injuries were caused by black sea urchins and were observed in bathers. The lesions and the pain were associated with penetration of the spines; there was no early inflammation or pain without pressure on the wounded places. Complications arising from this kind on injury, including infections and foreign body granulomas, are associated with the permanence of the spines in the wounds. CONCLUSIONS: The study confirmed that this kind of injury is the most common accident caused by aquatic animals in Brazil. The main therapeutical recommendation is early removal of the spines to prevent late complications, such as infections and the formation of foreign body granulomas.

Knowledge management framework based on brain models and human physiology

The life of humans and most living beings depend on sensation and perception for the best assessment of the surrounding world. Sensorial organs acquire a variety of stimuli that are interpreted and integrated in our brain for immediate use or stored in memory for later recall. Among the reasoning aspects, a person has to decide what to do with available information. Emotions are classifiers of collected information, assigning a personal meaning to objects, events and individuals, making part of our own identity. Emotions play a decisive role in cognitive processes as reasoning, decision and memory by assigning relevance to collected information. The access to pervasive computing devices, empowered by the ability to sense and perceive the world, provides new forms of acquiring and integrating information. But prior to data assessment on its usefulness, systems must capture and ensure that data is properly managed for diverse possible goals. Portable and wearable devices are now able to gather and store information, from the environment and from our body, using cloud based services and Internet connections. Systems limitations in handling sensorial data, compared with our sensorial capabilities constitute an identified problem. Another problem is the lack of interoperability between humans and devices, as they do not properly understand human’s emotional states and human needs. Addressing those problems is a motivation for the present research work. The mission hereby assumed is to include sensorial and physiological data into a Framework that will be able to manage collected data towards human cognitive functions, supported by a new data model. By learning from selected human functional and behavioural models and reasoning over collected data, the Framework aims at providing evaluation on a person’s emotional state, for empowering human centric applications, along with the capability of storing episodic information on a person’s life with physiologic indicators on emotional states to be used by new generation applications.

Soap bubble appearance in brain magnetic resonance imaging: cryptococcal meningoencephalitis

Although cryptococcal infections begin in the lungs, meningoencephalitis is the most frequently encountered manifestation of cryptococcosis among individuals with advanced immunosuppression. As the infection progresses along the Virchow-Robin spaces, these structures may become dilated with mucoid material produced by the capsule of the organism. We report a case of a 24-year-old man with cryptococcal meningoencephalitis in which magnetic resonance imaging showed clusters of gelatinous pseudocysts in the periventricular white matter, basal ganglia, mammillary bodies, midbrain peduncles and nucleus dentatus with a soap bubble appearance.

Brain schistosomiasis in mice experimentally infected with Schistosoma mansoni

Introduction Human neuroschistosomiasis has been reported in the literature, but the possibility of modeling neuroschistosomiasis in mice is controversial. Methods In two research laboratories in Brazil that maintain the Schistosoma mansoni life cycle in rodents, two mice developed signs of brain disease (hemiplegia and spinning), and both were autopsied. Results S. mansoni eggs, both with and without granuloma formation, were observed in the brain and meninges of both mice by optical microscopy. Conclusions This is the first description of eggs in the brains of symptomatic mice that were experimentally infected with S. mansoni. An investigation of experimental neuroschistosomiasis is now feasible.

Puerperal brain cryptococcoma in an HIV-negative woman successfully treated with fluconazole: a case report

Cryptococcus spp. cerebral abscesses are uncommon in immunocompetent subjects. The recommended induction treatment is the administration of amphotericin B plus flucytosine combined with resection for lesions ≥3cm. In this paper, we describe an HIV-negative woman diagnosed with a large cryptococcoma in the immediate postpartum period. The lesion was not resected, and due to amphotericin B intolerance, she received an extended course of fluconazole monotherapy. There was no disease recurrence during the 4 years of follow-up. The abrupt onset of her symptoms following delivery suggests that she developed a postpartum immune reconstitution syndrome. This case also demonstrates that in specific situations fluconazole monotherapy can be attempted in immunocompetent patients with cryptococcoma.

Injuries caused by aquatic animals in Brazil: an analysis of the data present in the information system for notifiable diseases

AbstractINTRODUCTION:We present a review of injuries in humans caused by aquatic animals in Brazil using the Information System for Notifiable Diseases [ Sistema de Informação de Agravos de Notificação (SINAN)] database.METHODS:A descriptive and retrospective epidemiological study was conducted from 2007 to 2013.RESULTS:A total of 4,118 accidents were recorded. Of these accidents, 88.7% (3,651) were caused by venomous species, and 11.3% (467) were caused by poisonous, traumatic or unidentified aquatic animals. Most of the events were injuries by stingrays (69%) and jellyfish (13.1%). The North region was responsible for the majority of reports (66.2%), with a significant emphasis on accidents caused by freshwater stingrays (92.2% or 2,317 cases). In the South region, the region with the second highest number of records (15.7%), jellyfish caused the majority of accidents (83.7% or 452 cases). The Northeastern region, with 12.5% of the records, was notable because almost all accidents were caused by toadfish (95.6% or 174 cases).CONCLUSIONS:Although a comparison of different databases has not been performed, the data presented in this study, compared to local and regional surveys, raises the hypothesis of underreporting of accidents. As the SINAN is the official system for the notification of accidents by venomous animals in Brazil, it is imperative that its operation be reviewed and improved, given that effective measures to prevent accidents by venomous animals depend on a reliable database and the ability to accurately report the true conditions.

Venomous and poisonous arthropods: identification, clinical manifestations of envenomation, and treatments used in human injuries

Abstract This review presents the main species of venomous and poisonous arthropods, with commentary on the clinical manifestations provoked by the toxins and therapeutic measures used to treat human envenomations. The groups of arthopods discussed include the class Arachnida (spiders and scorpions, which are responsible for many injuries reported worldwide, including Brazil); the subphylum Myriapoda, with the classes Chilopoda and Diplopoda (centipedes and millipedes); and the subphylum Hexapoda, with the class Insecta and the orders Coleoptera (beetles), Hemiptera (stink bugs, giant water bugs, and cicadas), Hymenoptera (ants, wasps, and bees), and Lepidoptera (butterflies and moths).

Effect of hyperbaric oxygen on the regeneration of experimental crush injuries of nerves

Hyperbaric oxygen has been successfully used on treatment of acute ischemic injuries involving soft tissues and chronic injuries. In nerve crush injuries, the mechanisms involved are very similar to those found in ischemic injuries. Consequently, it is logical to hypothesize that hyperbaric oxygen should improve nerve repair, which is a critical step on functional recovery. In the present study, we created standard nerve crush injuries on sciatic nerves of rats, which underwent treatment with hyperbaric oxygen. Results were assessed by functional evaluation using walking-track analysis. The functional recovery indexes observed did not differ from control group. We concluded that hyperbaric oxygen therapy, in the schedule used, had no influence on functional recovery after nerve crush injuries.

Chemotherapy versus best supportive care in stage IV non-small cell lung cancer, non metastatic to the brain

Stage IV non-small cell lung cancer is a fatal disease, with a median survival of 14 months. Systemic chemotherapy is the most common approach. However the impact in overall survival and quality of life still a controversy. OBJECTIVES: To determine differences in overall survival and quality of life among patients with stage IV non-small cell lung cancer non-metastatic to the brain treated with best supportive care versus systemic chemotherapy. PATIENTS: From February 1990 through December 1995, 78 eligible patients were admitted with the diagnosis of stage IV non-small cell lung cancer . Patients were divided in 2 groups: Group A (n=31 -- treated with best supportive care ), and Group B (n=47 -- treated with systemic chemotherapy). RESULTS: The median survival time was 23 weeks (range 5 -- 153 weeks) in Group A and 55 weeks (range 7.4 -- 213 weeks) in Group B (p=0.0018). In both groups, the incidence of admission for IV antibiotics and need of blood transfusions were similar. Patients receiving systemic chemotherapy were also stratified into those receiving mytomycin, vinblastin, and cisplatinum, n=25 and those receiving other combination regimens (platinum derivatives associated with other drugs, n=22). Patients receiving mytomycin, vinblastin, and cisplatinum, n=25 had a higher incidence of febrile neutropenia and had their cycles delayed for longer periods of time than the other group. These patients also had a shorter median survival time (51 versus 66 weeks, p=0.005). CONCLUSION: In patients with stage IV non-small cell lung cancer, non-metastatic to the brain, chemotherapy significantly increases survival compared with best supportive care.