The role of neurogenesis in neurorepair after ischemic stroke.

Stroke consists of an abrupt reduction of cerebral blood flow resulting in hypoxia that triggers an excitotoxicity, oxidative stress, and neuroinflammation. After the ischemic process, neural precursor cells present in the subventricular zone of the lateral ventricle and subgranular zone of the dentate gyrus proliferate and migrate towards the lesion, contributing to the brain repair. The neurogenesis is induced by signal transduction pathways, growth factors, attractive factors for neuroblasts, transcription factors, pro and anti-inflammatory mediators and specific neurotransmissions. However, this endogenous neurogenesis occurs slowly and does not allow a complete restoration of brain function. Despite that, understanding the mechanisms of neurogenesis could improve the therapeutic strategies for brain repair. This review presents the current knowledge about brain repair process after stroke and the perspectives regarding the development of promising therapies that aim to improve neurogenesis and its potential to form new neural networks.

Drugs and Endogenous Factors as Protagonists in Neurogenic Stimulation.

Neurogenesis is a biological process characterized by new neurons formation from stem cells. For decades, it was believed that neurons only multiplied during development and in the postnatal period but the discovery of neural stem cells (NSCs) in mature brain promoted a revolution in neuroscience field. In mammals, neurogenesis consists of migration, differentiation, maturation, as well as functional integration of newborn cells into the pre-existing neuronal circuit. Actually, NSC density drops significantly after the first stages of development, however in specific places in the brain, called neurogenic niches, some of these cells retain their ability to generate new neurons and glial cells in adulthood. The subgranular (SGZ), and the subventricular zones (SVZ) are examples of regions where the neurogenesis process occurs in the mature brain. There, the potential of NSCs to produce new neurons has been explored by new advanced methodologies and in neuroscience for the treatment of brain damage and/or degeneration. Based on that, this review highlights endogenous factors and drugs capable of stimulating neurogenesis, as well as the perspectives for the use of NSCs for neurological and neurodegenerative diseases.

Long-term evaluation of three satellite ocean color algorithms for identifying harmful algal blooms (Karenia brevis) along the west coast of Florida: A matchup assessment.

We present a simple algorithm to identify Karenia brevis blooms in the Gulf of Mexico along the west coast of Florida in satellite imagery. It is based on an empirical analysis of collocated matchups of satellite and in situ measurements. The results of this Empirical Approach is compared to those of a Bio-optical Technique - taken from the published literature - and the Operational Method currently implemented by the NOAA Harmful Algal Bloom Forecasting System for K. brevis blooms. These three algorithms are evaluated using a multi-year MODIS data set (from July, 2002 to October, 2006) and a long-term in situ database. Matchup pairs, consisting of remotely-sensed ocean color parameters and near-coincident field measurements of K. brevis concentration, are used to assess the accuracy of the algorithms. Fair evaluation of the algorithms was only possible in the central west Florida shelf (i.e. between 25.75°N and 28.25°N) during the boreal Summer and Fall months (i.e. July to December) due to the availability of valid cloud-free matchups. Even though the predictive values of the three algorithms are similar, the statistical measure of success in red tide identification (defined as cell counts in excess of 1.5 × 10(4) cells L(-1)) varied considerably (sensitivity-Empirical: 86%; Bio-optical: 77%; Operational: 26%), as did their effectiveness in identifying non-bloom cases (specificity-Empirical: 53%; Bio-optical: 65%; Operational: 84%). As the Operational Method had an elevated frequency of false-negative cases (i.e. presented low accuracy in detecting known red tides), and because of the considerable overlap between the optical characteristics of the red tide and non-bloom population, only the other two algorithms underwent a procedure for further inspecting possible detection improvements. Both optimized versions of the Empirical and Bio-optical algorithms performed similarly, being equally specific and sensitive (~70% for both) and showing low levels of uncertainties (i.e. few cases of false-negatives and false-positives: ~30%)-improved positive predictive values (~60%) were also observed along with good negative predictive values (~80%).

Satellite remote sensing of harmful algal blooms: A new multi-algorithm method for detecting the Florida Red Tide (Karenia brevis).

In a continuing effort to develop suitable methods for the surveillance of Harmful Algal Blooms (HABs) of Karenia brevis using satellite radiometers, a new multi-algorithm method was developed to explore whether improvements in the remote sensing detection of the Florida Red Tide was possible. A Hybrid Scheme was introduced that sequentially applies the optimized versions of two pre-existing satellite-based algorithms: an Empirical Approach (using water-leaving radiance as a function of chlorophyll concentration) and a Bio-optical Technique (using particulate backscatter along with chlorophyll concentration). The long-term evaluation of the new multi-algorithm method was performed using a multi-year MODIS dataset (2002 to 2006; during the boreal Summer-Fall periods - July to December) along the Central West Florida Shelf between 25.75°N and 28.25°N. Algorithm validation was done with in situ measurements of the abundances of K. brevis; cell counts ≥1.5×10(4) cells l(-1) defined a detectable HAB. Encouraging statistical results were derived when either or both algorithms correctly flagged known samples. The majority of the valid match-ups were correctly identified (~80% of both HABs and non-blooming conditions) and few false negatives or false positives were produced (~20% of each). Additionally, most of the HAB-positive identifications in the satellite data were indeed HAB samples (positive predictive value: ~70%) and those classified as HAB-negative were almost all non-bloom cases (negative predictive value: ~86%). These results demonstrate an excellent detection capability, on average ~10% more accurate than the individual algorithms used separately. Thus, the new Hybrid Scheme could become a powerful tool for environmental monitoring of K. brevis blooms, with valuable consequences including leading to the more rapid and efficient use of ships to make in situ measurements of HABs.

Hamartomas of the internal auditory canal: report of two cases.

OBJECTIVE AND IMPORTANCE: To highlight the clinical, radiological, and surgical findings and therapeutic options for this rare entity, which may mimic a purely intrameatal vestibular schwannoma, and to define the particular aspects of preoperative differential diagnosis and surgical management. CLINICAL PRESENTATION: Two patients presented with clinical findings typical of vestibular schwannomas, i.e., tinnitus, hearing loss of 30 dB, and an intrameatal contrast-enhancing lesion on magnetic resonance imaging studies. TECHNIQUE: The lesions were exposed via a suboccipital transmeatal approach, and tumor infiltration of the cochlear and/or facial cranial nerves was identified. In view of the unclear intraoperative histology, surgical management was based on criteria of cranial nerve function. In Patient 1, after nerve decompression by subtotal tumor removal, preserved auditory brainstem responses and facial nerve electromyography indicated functional nerve preservation and facilitated the decision for partial resection. In Patient 2, minimal tumor dissection resulted in complete loss of auditory brainstem response without reversibility. Therefore, a radical tumor removal was performed that sacrificed the cochlear but preserved the facial nerve. CONCLUSION: Symptoms and signs of internal auditory canal hamartomas are congruent with other typical pathological lesions of the internal auditory canal and cerebellopontine angle. Accurate preoperative diagnosis by radiological means is not possible, but careful evaluation of the different signal intensities on magnetic resonance imaging studies may indicate this rare pathological condition. Intraoperative surgical findings of tumor infiltration of the faciocochlear cranial nerve complex may support simple observation. In view of the nonneoplastic characteristic of these lesions, a more conservative approach is justified. The decision should be based on the functional status of the cranial nerves, for which reliable electrophysiological monitoring is indispensable.

Relationship between thoracic kyphosis, bone mineral density, and postural control in elderly women.

OBJECTIVES: To verify the relationship between the angle of thoracic kyphosis, bone mineral density, and postural control in elderly women. METHODS: Through a cross-sectional study, 95 elderly participants were subdivided into four groups according to the thoracic kyphosis angle (obtained by the flexicurve method) and to bone densitometry results. On the force platform and through the dynamic test, stabilometric data were obtained. For statistical analysis, we assessed the performance of each group on the force platform by non-parametric tests: between group comparison (Mann-Whitney) and within group comparison according to the condition of the eyes - open or closed (Signed Rank). RESULTS: On the force platform, the only statistically significant difference was found between groups 1 (loss of bone mass and increased thoracic kyphosis) and 3 (no loss of bone mass or increase in thoracic kyphosis) in the anteroposterior direction (p=0.0124). All groups presented different performances with the eyes open and closed in the mediolateral direction, except for group 3 (p=0.4263), whereas in the anteroposterior direction, we did not observe differences. CONCLUSION: The results suggest an influence of the angle of thoracic kyphosis and bone mineral density on the postural control of our sample in the anteroposterior direction and in the standing position.

Relationship between quadriceps angle (Q) and plantar pressure distribution in football players.

OBJECTIVES: To determine whether there is an association between the Q-angle (Q) and the distribution of plantar pressure in football players, and to compare the characteristics of these athletes with non-practitioners of this sport. METHODS: 121 male participants were selected: 50 football practitioners (FP) and 71 non-practitioners (NP). We concurrently evaluated the Q-angle and the plantar pressure through the software of postural assessment (SPA) and the F-Mat System, respectively. To verify the correlation between the Q-angle and peak pressure values in four segments of the foot (medial and lateral forefoot, medium-foot and hind-foot), the Pearson coefficient (r) for parametric analysis was used. The independent t-test was used to compare these variables between the groups. Data normality was verified by the skewness values, adopting a significance level of 5%. RESULTS: A negative and weak correlation was found (r=-0.32) between the Q-angle and the plantar pressure in the right medium-foot. The groups differed with regards to the right Q-angle (11.36º in FP versus 13.80º in NP) and the left Q-angle (11.03º in FP versus 13.96º in NP). Plantar pressure was also different between the groups, with FP showing higher mean values for the right side and for the left side of the forefoot (0.77 kg/cm² in FP versus 0.63 kg/cm² in NP, and 0.65 kg/cm² in FP versus 0.54 kg/cm² in NP, respectively). However, mean peak pressure values for the left medium-foot were higher among NP (0.37 kg/cm² in FP versus 0.46 kg/cm² in NP). CONCLUSIONS: There was no evidence of an association between the Q-angle and the distribution of plantar pressure in FP. The athletes showed reduced Q-angle values and higher mean peak pressure values for the right and left aspects of the forefoot, suggesting a varus malalignment and a supine distribution of plantar bases.

Relação entre cifose dorsal, densidade mineral óssea e controle postural em idosas / Relationship between thoracic kyphosis, bone mineral density, and postural control in elderly women

OBJETIVO: Verificar a relação entre medida angular da cifose dorsal, densidade mineral óssea (DMO) e controle postural em mulheres idosas. MÉTODOS: Por meio de um estudo transversal, 95 idosas foram divididas em quatro grupos segundo as medidas angulares da cifose dorsal (obtidas pelo método flexicurva) e os resultados de densitometria óssea. Na plataforma de força e por meio de teste dinâmico, foram obtidos os dados estabilométricos. Para fins estatísticos, analisou-se apenas o desempenho, na plataforma de força, de cada grupo por meio de testes não paramétricos, um grupo em relação ao outro (Mann-Whitney), e segundo a condição dos olhos - abertos ou fechados (Signed Rank). RESULTADOS: Na plataforma de força, houve diferença estatisticamente significativa apenas entre os desempenhos dos grupos 1 (com perda de massa óssea e com aumento da cifose dorsal) e 3 (sem perda de massa óssea e sem aumento da cifose dorsal) na direção ântero-posterior (AP) (p=0,0124). Com exceção do grupo 3 (p=0,4263), todos os demais grupos apresentaram diferença no desempenho entre as tentativas de olhos abertos (OAs) e de olhos fechados (OFs) na direção médio-lateral (ML), enquanto que, na direção AP, nenhum grupo apresentou diferença entre as tentativas. CONCLUSÃO: Os resultados da pesquisa sugerem que houve influência da medida angular da cifose dorsal e da DMO no controle postural na direção AP e na posição ortostática na população estudada.

OBJECTIVES: To verify the relationship between the angle of thoracic kyphosis, bone mineral density, and postural control in elderly women. METHODS: Through a cross-sectional study, 95 elderly participants were subdivided into four groups according to the thoracic kyphosis angle (obtained by the flexicurve method) and to bone densitometry results. On the force platform and through the dynamic test, stabilometric data were obtained. For statistical analysis, we assessed the performance of each group on the force platform by non-parametric tests: between group comparison (Mann-Whitney) and within group comparison according to the condition of the eyes - open or closed (Signed Rank). RESULTS: On the force platform, the only statistically significant difference was found between groups 1 (loss of bone mass and increased thoracic kyphosis) and 3 (no loss of bone mass or increase in thoracic kyphosis) in the anteroposterior direction (p=0.0124). All groups presented different performances with the eyes open and closed in the mediolateral direction, except for group 3 (p=0.4263), whereas in the anteroposterior direction, we did not observe differences. CONCLUSION: The results suggest an influence of the angle of thoracic kyphosis and bone mineral density on the postural control of our sample in the anteroposterior direction and in the standing position.

Relação entre o ângulo quadriciptal (ÂQ) e a distribuição da pressão plantar em jogadores de futebol / Relationship between quadriceps angle (Q) and plantar pressure distribution in football players

OBJETIVOS: Verificar possível associação entre ângulo quadriciptal (ÂQ) e distribuição de pressão plantar em jogadores de futebol, comparando-os com indivíduos não praticantes da modalidade. MÉTODOS: Cento e vinte e um participantes do sexo masculino foram selecionados: 50 jogadores de futebol (JF) e 71 sujeitos para o grupo controle (GC). Avaliaram-se concomitantemente o ÂQ, por meio do Software para Avaliação Postural (SAPO), e a pressão plantar, pela plataforma F-Scan/F-Mat System. Para verificar correlação entre o ÂQ e os valores de picos de pressão em quatro segmentos do pé (antepé medial e lateral, médio-pé e retropé), utilizou-se o Coeficiente de Pearson (r) para análises paramétricas. O teste t independente foi empregado para comparar isoladamente essas mesmas variáveis entre os grupos. A normalidade dos dados foi verificada pelos valores de skewness, adotando nível de significância de 5 por cento. RESULTADOS: Encontrou-se correlação negativa e fraca (r=-0,32) somente entre ÂQ e médio-pé direito. Os grupos diferiram quanto ao ÂQ bilateralmente, sendo que o grupo JF teve média de 11,36º, e GC, de 13,80º à direita e de 11,03º contra 13,96º à esquerda, respectivamente. Em relação à pressão plantar, o JF teve maior média de força nas faces laterais do antepé direito (0,77 contra 0,63 kg/cm²) e esquerdo (0,65 e 0,54 kg/cm²), enquanto o GC apresentou maior pico de pressão no médio-pé esquerdo (JF: 0,37 e GC: 0,46 kg/cm²). CONCLUSÕES: Não houve relação entre os valores de ÂQ na distribuição da pressão plantar nos jogadores de futebol. Os atletas apresentaram, porém, ÂQ diminuído e maiores picos de pressão nas faces laterais de ambos os pés, o que sugere alinhamento em varo dos joelhos e distribuição supinada das bases plantares.

OBJECTIVES: To determine whether there is an association between the Q-angle (Q) and the distribution of plantar pressure in football players, and to compare the characteristics of these athletes with non-practitioners of this sport. METHODS: 121 male participants were selected: 50 football practitioners (FP) and 71 non-practitioners (NP). We concurrently evaluated the Q-angle and the plantar pressure through the software of postural assessment (SPA) and the F-Mat System, respectively. To verify the correlation between the Q-angle and peak pressure values in four segments of the foot (medial and lateral forefoot, medium-foot and hind-foot), the Pearson coefficient (r) for parametric analysis was used. The independent t-test was used to compare these variables between the groups. Data normality was verified by the skewness values, adopting a significance level of 5 percent. RESULTS: A negative and weak correlation was found (r=-0.32) between the Q-angle and the plantar pressure in the right medium-foot. The groups differed with regards to the right Q-angle (11.36º in FP versus 13.80º in NP) and the left Q-angle (11.03º in FP versus 13.96º in NP). Plantar pressure was also different between the groups, with FP showing higher mean values for the right side and for the left side of the forefoot (0.77 kg/cm² in FP versus 0.63 kg/cm² in NP, and 0.65 kg/cm² in FP versus 0.54 kg/cm² in NP, respectively). However, mean peak pressure values for the left medium-foot were higher among NP (0.37 kg/cm² in FP versus 0.46 kg/cm² in NP). CONCLUSIONS: There was no evidence of an association between the Q-angle and the distribution of plantar pressure in FP. The athletes showed reduced Q-angle values and higher mean peak pressure values for the right and left aspects of the forefoot, suggesting a varus malalignment and a supine distribution of plantar bases.

Avaliação da sensibilidade cutânea palmar nas aplicações de crioterapia por bolsa de gelo e bolsa de gel / Evaluation of the cutaneous sensibility palmar in the cryotherapy applications for ice packs and gel packs

A crioterapia é muito utilizada nas afecções traumáticas, principalmente, nas lesões músculos-esqueléticas. Entretanto, se aplicada de forma incorreta, sem conhecimento dos fenômenos neuro-fisiológicos, musculares e vasculares, poderá trazer conseqüências indesejáveis, interferindo diretamente na qualidade do tratamento. Esse estudo teve como objetivo verificar se existe alteração da sensibilidade cutânea nas aplicações de bolsa de gelo e bolsa de gel e qual sua magnitude, comparando-as entre si para verificar se poderia, diante destas circunstâncias, ocorrer interferências significativas nas aplicações das terapias combinadas. Realizou-se uma série de casos com uma amostra de vinte voluntários que recebiam as duas formas de aplicação de crioterapia, uma logo após a outra. A aplicação da modalidade durava vinte e cinco minutos, sendo que a sensibilidade cutânea foi aferida antes, durante e depois da aplicação, utilizando-se os monofilamentos de Semmes-Weinstein. Os resultados revelaram uma alteração significativa da sensibilidade cutânea com a diminuição da temperatura, desta forma a bolsa de gelo obteve uma maior alteração da sensibilidade do que a bolsa de gel. Concluímos que a associação da crioterapia com qualquer outra terapia que necessite da sensibilidade preservada é contra-indicada. No entanto, cinco minutos após a retirada da modalidade fria, observou-se que podemos aplicar qualquer técnica sem perigo.

Cryotherapy is very used in the treatment of traumatism, mostly in the muscle-skeleton lesions. However, if applied without neuro-physiological, muscular and vascular knowledge, it may bring unwanted consequences which may directly chip in the quality of the treatment. The present study aimed to checkthe existence of alteration in the cutaneous sensibility with the application of ice packs and gel packs andto check in which extent it should be applied. A comparison among these techniques was done to check if there could be significant interferences in the application of combined therapies in these circumstances. A cases series was done with a sample of twenty volunteers which received both forms of cryotherapy one just after the other. The application was done for a period of twenty-five minutes and the skin sensibility was checked before, during and after the application, using Semmes-Weinstein monofilaments. The results revealed a significant alteration in the cutaneous sensibility with the decrease of temperature. The ice pack had a greater alteration of sensibility than the gel pack. The conclusion was that the association of cryotherapy with any other therapy that needs to preserve skin sensibility is not recommended. However, five minutes after the application of the cold therapy was observed that any technique may be applied without danger.