Cerebral blood flow and vasoreactivity in aging: an arterial spin labeling study

Regional cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in young and elderly participants were assessed using pulsed arterial spin labeling (ASL) and blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) techniques in combination with inhalation of CO2. Pulsed ASL and BOLD-MRI were acquired in seventeen asymptomatic volunteers (10 young adults, age: 30±7 years; 7 elderly adults, age: 64±8 years) with no history of diabetes, hypertension, and neurological diseases. Data from one elderly participant was excluded due to the incorrigible head motion. Average baseline CBF in gray matter was significantly reduced in elderly (46±9 mL·100 g-1·min-1) compared to young adults (57±8 mL·100 g-1·min-1; P=0.02). Decreased pulsed ASL-CVR and BOLD-CVR in gray matter were also observed in elderly (2.12±1.30 and 0.13±0.06 %/mmHg, respectively) compared to young adults (3.28±1.43 and 0.28±0.11 %/mmHg, respectively; P<0.05), suggesting some degree of vascular impairment with aging. Moreover, age-related decrease in baseline CBF was observed in different brain regions (inferior, middle and superior frontal gyri; precentral and postcentral gyri; superior temporal gyrus; cingulate gyri; insula, putamen, caudate, and supramarginal gyrus). In conclusion, CBF and CVR were successfully investigated using a protocol that causes minimal or no discomfort for the participants. Age-related decreases in baseline CBF and CVR were observed in the cerebral cortex, which may be related to the vulnerability for neurological disorders in aging.

Intervencionismo coronario percutáneo en Navarra. Resultados de un centro de bajo volumen intervencionista / Percutaneous coronary intervention in Navarre. Outcomes of a low volume centre

Fundamento: El intervencionismo coronario percutáneo (PCI) es una opción terapéutica fundamental en pacientes con enfermedad coronaria. Para realizarla los especialistas deben formarse y acreditarse. Se sabe que el número de procedimientos realizados al año influye en los resultados. Pretendemos mostrar que con un bajo volumen de PCI algunos centros obtienen buenos resultados. Método: Análisis prospectivo de las características clínicas y resultados inmediatos obtenidos en nuestro centro con el PCI entre 2006 y 2012 y análisis retrospectivo de la supervivencia global, supervivencia libre de eventos y reestenosis de los PCI realizados entre 2006 y 2009. Se compararon las características clínicas, los eventos agudos y a largo plazo (complicaciones, supervivencia y mortalidad) entre nuestros pacientes y los de algunos trabajos publicados. Resultados: Nuestra probabilidad de tener cualquier complicación en un PCI fue del 9% con una mortalidad global del 2%. La mortalidad del PCI en situación estable fue del 0,43% y en el síndrome coronario agudo del 6,25%. Las complicaciones en el lugar del acceso vascular fueron del 1,44% y la incidencia de reestenosis a los nueve meses, en pacientes sometidos por primera vez a PCI, fue del 5,2%. Conclusiones: Aunque el alto volumen intervencionista ha demostrado ser importante para tener una baja tasa de complicaciones y una buena evolución a largo plazo, hay centros con bajo volumen intervencionista que por sus características pueden obtener resultados equiparables a los de alto volumen (AU)

Background: Percutaneous coronary intervention (PCI) is currently a basic therapeutic option in patients with coronary artery disease. To carry this out specialists must be trained and accredited. It is known that the number of procedures performed each year influences results. We suggest that some low volume centres may also get good results. Methods: Prospective analysis of clinical features and immediate results obtained in our centre following PCI performed between 2006 and 2012 and retrospective analysis of overall survival, outcome-free survival and restenosis in patients treated between 2006 and 2009. The clinical features, acute and long-term events (complications, survival and mortality) of our group were compared with other published studies. Results: In our centre the likelihood of complications in a PCI was 9% with an overall mortality of 2%. PCI mortality in stable coronary disease was 0.43% and in acute coronary syndrome 6.25%. Complications at the vascular access site was 1.44% and restenosis at nine months, in patients undergoing PCI for the first time, was 5.2%. Conclusions: Although a high interventionist volume has been shown to reduce the rate of complications and improve long-term evolution, some low volume interventional centres can obtain similar results to those of high volume interventional centres (AU)

Indução prévia de LTP na via CA1-córtex pré-frontal medial de ratos bloqueia os prejuízos de plasticidade pré-sináptica induzidos por modelo de psicose pós-ictal in vivo / Prevention of the CA1-mPFC pre-synaptic plasticity impairments in a post-ictal psychosis model 'in vivo'

O objetivo do presente trabalho foi testar se a indução de potenciação de longa duração (LTP) no córtex frontal seria capaz de bloquear os efeitos depressores sobre a plasticidade pré-sináptica da via hipocampo (CA1)-córtex pré-frontal medial (mPFC) induzidos por pós-descarga no hipocampo (AD; atividade epiléptica) ou pela injeção sistêmica de cetamina (KET; modelo farmacológico de psicose). Ratos anestesiados com uretana receberam implantes de eletrodos de estimulação e registro, em CA1 e mPFC, respectivamente. Estímulos elétricos monofásicos pareados foram aplicados em CA1 a cada 20s para eliciar potenciais pós-sinápticos de campo (P1 e P2) no mPFC. Avaliamos a plasticidade de curta duração através da facilitação por pulso pareado (PPF), definida pela razão entre as amplitudes de P2 e P1. Após 90min de registros de linha de base, grupos independentes de animais receberam aplicação de AD, injeção de KET-S(+) (12,5 mg/kg i.p.) ou injeção de veículo (NaCl 0,15M), e foram registrados por mais 120min. Em outro experimento registramos 30min de linha de base e aplicamos estímulos de alta frequência (HFS) para indução de LTP aos 30 e 60min. Trinta minutos depois, os animais receberam KET, AD ou veículo e tiveram seus potenciais corticais registrados por mais 120 min. Nossos resultados mostram que AD gera significativa redução (-50%) da eficiência de transmissão basal na via CA1-mPFC, enquanto KET promove leve aumento (+10%). Ambos os tratamentos também promovem prejuízo significativo da PPF na mesma via (-15%). Além disso, observamos que a indução prévia de LTP atenua as alterações da eficiência basal e bloqueia os prejuízos da PPF na via CA1-mPFC induzidos por KET e AD. Nossos achados reforçam evidências recentes de que moduladores alostéricos positivos de NMDA e AMPA atenuam os prejuízos cognitivos em modelos animais de psicose. Acreditamos, portanto, que a aplicação prévia de HFS na região CA1 do hipocampo pode ser uma ferramenta útil para melhor entendermos como prevenir os prejuízos de plasticidade sináptica no mPFC em modelos de psicose e psicose pós-ictal.

The present work aimed to test whether the induction of cortical long-term potentiation (LTP) was able to prevent the presynaptic plasticity impairment in the hippocampus (CA1)-medial prefrontal cortex (mPFC) pathway induced by hippocampal after-discharge (AD; epileptic activity) or systemic injection of ketamine (KET; pharmacological model of psychosis). Electrodes were stereotaxically positioned into CA1 and mPFC in urethane-anesthetized rats. Monophasic paired-pulses of electrical stimuli were applied to CA1 in order to evoke field post-synaptic potentials (P1 and P2) in the mPFC every 20s. Short-term plasticity was evaluated by measuring paired-pulse facilitation (PPF), defined as the amplitude ratio P2/P1. After 90min of baseline recordings, three independent groups of animals received hippocampal-AD, KET-S(+) (12.5mg/kg, i.p.) or vehicle (NaCl 0.15M) followed by 120min of evoked response monitoring. In an additional experiment, two applications of high-frequency stimuli (HFS) were given at 30 and 60min after baseline. Thirty minutes after the second HFS, the rats received KET, AD or vehicle and their cortical evoked potentials were monitored for further 120min. Our results showed that AD significantly decreased (-50%) whereas KET enhanced (+10%) CA1-mPFC basal synaptic transmission. In addition, AD and KET similarly impaired short-term plasticity in the mPFC (-15%). Interestingly, pre-induction of LTP in the mPFC prevented the PPF disruption induced by KET and AD. Altogether, our findings support recent evidences that positive allosteric modulators of NMDA and AMPA receptors attenuate cognitive impairments in animal models of psychosis. We believe that controlled HFS in CA1 can be a useful tool to better understand how to prevent synaptic plasticity disruptions observed in experimental models of psychosis and pos-ictal psychosis.