Primitive reflexes and cognitive function Reflexos primitivos e função cognitiva

BACKGROUND: Data on the prevalence of primitive reflexes (PR) in adulthood, their pathological significance and relationship to age and cognition are controversial. OBJECTIVE: To study the relationship between PR and cognition in 30 patients with probable Alzheimer's disease (AD) and 154 control subjects. METHOD: Diagnosis of probable AD was based on DSM-IV, NINCDS-ADRDA, and CAMDEX criteria. Primitive reflexes were quantified from zero (absent) to 1 (mild) or 2 (markedly present). The Cognitive Abilities Screening Instrument - Short Form (CASI-S) was used to evaluate registration, temporal orientation, verbal fluency and recall. A drawing test was added. RESULTS: Most frequent PR among demented and controls were suck (77% and 62%, respectively) and snout (60% and 27%), followed by glabellar (30% and 19%), paratonia (37% and 5%), and palmomental (23% and 5%). None of controls had more than three PR. Frequency of PR tended to increase with age and cognitive deterioration. Grasp and Babinski responses were found only in dementia patients. Primitive reflexes were not correlated with each other, except snout with suck, and snout with glabellar reflex. CONCLUSION: The finding of grasp and Babinski sign, or the presence of more than three primitive signs, particularly the combination of paratonia, snout, suck, and palmomental reflexes strongly suggests brain dysfunction, especially when these signs are marked and accompanied by deficits in orientation, recall, verbal fluency, and constructional praxis.<br>CONTEXTO: A prevalência e significado patológico dos reflexos primitivos (RP) no adulto, bem como sua relação com a idade e a cognição, são questões controversas. OBJETIVO: Estudar a relação entre RP e cognição em 30 pacientes com doença de Alzheimer (DA) e 154 sujeitos controles normais. MÉTODO: O diagnóstico de DA baseou-se nos critérios DSM-IV, NINCDS-ADRDA e CAMDEX. Os RP foram quantificados de 0 (ausente) a 1 (leve) ou 2 (acentuado). CASI-S (Cognitive Abilities Screening Instrument -Short Form) foi usado para avaliar o registro, orientação temporal, fluência verbal e evocação. Um teste de cópia de pentágonos foi acrescentado. RESULTADOS: Os RP mais frequentes nos pacientes e controles foram o de sucção (77% e 62%, respectivamente) e "snout" (60% e 27%), seguidos do glabelar (30% e 19%), paratonia (37% e 5%) e palmomentoniano (23% e 5%). Nenhum sujeito controle teve mais que três RP. A frequência dos RP tendeu a aumentar com a idade e a deterioração cognitiva. O reflexo de preensão e o sinal de Babinski foram encontrados apenas nos pacientes com DA. Os RP não se correlacionaram uns com os outros, exceto o reflexo "snout" com o de sucção e com o glabelar. CONCLUSÃO: O achado de reflexo de preensão e sinal de Babinski, ou a presença de mais de três sinais primitivos, particularmente a combinação de paratonia e reflexos "snout", sucção e palmomentoniano, são sugestivos de disfunção cerebral, especialmente quando esses sinais são acentuados e acompanhados de déficits de orientação, evocação, fluência verbal e praxia construcional

Resistance, epidemiology and sustainable management of Rhynchosporium secalis populations on barley

The definitive version can be found at: http://onlinelibrary.wiley.com/ Copyright Wiley-Blackwell [Full text of this article is not available in the UHRA]Rhynchosporium secalis is one of the most destructive pathogens of barley worldwide, causing yield decreases of up to 40% and reduced grain quality. Rhynchosporium is a polycyclic disease. Primary inoculum includes conidia produced on crop debris, infected seeds and possibly ascospores, although these have not yet been identified. Secondary disease spread is primarily by splash dispersal of conidia produced on infected leaves, which may be symptomless early in the growing season. Host resistance to R. secalis is mediated by both 'major' or host-specific genes (complete resistance) and 'minor' genes of smaller, generally additive effects (partial resistance). Crop growth stage and plant or canopy architecture can modify the expression of resistance. Resistance genes are distributed unevenly across the barley genome, with most being clustered on the short arms of chromosomes 1H, 3H, 6H and 7H, or in the centromeric region or on the long arm of chromosome 3H. Strategies used to manage rhynchosporium epidemics include cultivar resistance and fungicides, and also cultural practices such as crop rotation, cultivar mixtures and manipulation of sowing date, sowing rate or fertiliser rate. However, the high genetic variability of R. secalis can result in rapid adaptation of pathogen populations to render some of these control strategies ineffective when they are used alone. Sustainable control of rhynchosporium needs to integrate major-gene-mediated resistance, partial resistance and other strategies such as customized fungicide programmes, species or cultivar rotation, resistance gene deployment, clean seed and cultivar mixtures.Peer reviewe