Is it possible to measure hemodynamic changes in the prefrontal cortex through the frontal sinus using continuous wave DOT systems?

The present work shows the capability of near infrared (NIR) light to reach the cerebral cortex through the frontal sinus using continuous-wave techniques (CW-DOT) in a dual study. On the one hand, changes in time during the tracking of a blood dye in the prefrontal cortex were monitored. On the other hand, hemodynamic changes induced by low frequency of transcranial magnetic stimulation applied on the prefrontal cortex were recorded. The results show how NIR light projected through the frontal sinus reaches the cerebral cortex target, providing enough information to have a reliable measurement of cortical hemodynamic changes using CW-DOT.

Transcultural adaptation, validation and assessment of the psychometric properties of the spanish version of the Western Ontario Shoulder Instability Index questionnaire. / Adaptación transcultural, validación y valoración de las propiedades psicométricas, de la versión española del cuestionario Western Ontario Shoulder Instability Index.

OBJECTIVE: The aim of the present study is to present a transcultural adaptation and validation of the Western Ontario Shoulder Instability Index questionnaire into Spanish (Spain), and to assess its psychometric properties. MATERIAL AND METHODS: The transcultural adaptation was conducted according to sequential forward and backward translation approach. A pilot study was subsequently performed to ensure acceptable psychometric properties. The Western Ontario Shoulder Instability Index questionnaire was administered to 79 patients twice within a period of 2 months, and patients were stratified into 3 groups (cohorts). RESULTS: CONCLUSIONS: The Spanish version of the Western Ontario Shoulder Instability Index questionnaire is a valid, reliable tool, and highly sensitive to change to assess patients with shoulder instability.

Perioperative factors associated with acute kidney injury after partial nephrectomy.

BACKGROUND: Partial nephrectomy is performed with the aim to preserve renal function. But the occurrence of postoperative acute kidney injury (AKI) can interfere with this goal. Our primary aim was to evaluate associations between pre-specified modifiable factors and estimated glomerular filtration rate after partial nephrectomy. Our secondary aims were to evaluate associations between pre-specified modifiable factors and both serum creatinine concentration and type of nephrectomy. METHODS: The records of 1955 patients who underwent partial nephrectomy were collected. Postoperative estimated glomerular filtration rate (eGFR) was used as the primary outcome measure. Twenty modifiable risk factors were studied. A repeated-measures linear model with autoregressive within-subject correlation structure was used. The interaction between all the factors and type of nephrectomy was also studied. RESULTS: A total of 1187 (61%) patients had no kidney injury, 647 (33%) had stage I, 80 (4%) had stage II, and 41 (2%) had stage III injury. The mean eGFR increased an estimated 0.83 (99.76% CI 0.79-0.88) ml min(-1) 1.73 m(-2) for a unit increase in baseline eGFR. Mean eGFR was 2.65 (99.76% CI: 0.13, 5.18) ml min(-1) 1.73 m(-2) lower in patients with hypertension. Mean eGFR decreased 0.42 (99.76% CI: 0.22, 0.62) ml min(-1) 1.73 m(-2) for a 10-minute longer in duration of procedure and decreased 2.09 (99.76% CI: 1.39, 2.80) ml min(-1) 1.73 m(-2) for a 10-minute longer in ischemia time. It was 3.53 (99.76% CI: 0.83, 6.23) ml min(-1) 1.73 m(-2) lower for patients who received warm ischemia as compared to cold ischemia. CONCLUSION: Potentially modifiable factors associated with AKI in the postoperative period were identified as baseline renal function, preoperative hypertension, longer duration of surgical time and ischaemia time, and warm ischaemia.

The mirror neuron system and motor dexterity: what happens?

The mirror neuron system (MNS) is currently one of the most prominent areas of research in neuroscience. Some of the work has focused on the identification of factors that modulate its activity, but until now, no one has tried to identify the effect of motor ability on the MNS regions. The aim of the present work is to study a possible modulation of hand dexterity on the MNS activity. A blocked fMRI experiment has been designed, consisting of an execution condition, where participants must repeatedly perform a precision grasping pantomime, and an observation condition, where the same motor action is passively observed. A conjunction analysis was performed in order to confirm the existence of mirror activity. Moreover, participants were classified depending on their hand dexterity (measured with the Purdue Pegboard Test) as "High dexterity" or "Low dexterity" and a regression analysis was performed to investigate a possible linear relationship between the degree of dexterity and brain activity in the MNS. The conjunction analysis revealed, as expected, activity in the inferior parietal lobule, a region that constitutes one of the nuclei of the putative MNS and which is consistently activated by intransitive actions. The degree of dexterity only seems to modulate MNS regions during action execution. However, under the observation condition, no linear relationship of hand dexterity in MNS regions was registered in either the comparison between groups, or in the regression analysis. Therefore, the MNS network does not seem to be linearly modulated by the degree of motor dexterity, as occurs with other action-related factors like familiarity.

Simultaneous measurements of glucose, oxyhemoglobin and deoxyhemoglobin in exposed rat cortex.

The present work addresses the simultaneous monitoring of hemoglobin and glucose consumption in rat somatosensory cortex in vivo. We propose a method which combines two techniques: 2-dimensional optical imaging and an amperometric microbiosensor. The mounted setup optimizes the space in the cranial window so that three micro-electrodes can be inserted: glucose microbiosensor, sentinel and stimulating electrode as well as the holder to manipulate the optical fiber. Additionally, a tool based on graphical user interface programming has been developed to visualize a two-dimension spectral map of oxy-, deoxy- and total hemoglobin, HbO2, HbR and HbT respectively, in the cortex. Our results showed a good sensitivity, selectivity and spatial resolution for both methods. Relevant hemodynamic responses had a common central focus (at the site of the stimulus) which later segregated to other vascular compartments. A good linear relationship between extracellular glucose concentration and HbO2 values during brain activation after local electrical stimulation was observed for electrochemical and optical recordings (R² values were over 0.94). Time courses between glucose and HbO2 signals showed a temporal delay ranging from 1 s to 2 s, suggesting that both variables are not always coupled. The temporal mismatching reported here, provides in vivo evidence that supports a neuronal hypothesis: cerebral blow flow and oxidative metabolism are driven in parallel by neural activity--rather than a concatenation of events ('in-series' events) occurring at sites of neuronal activation.