Ultrafast inverse imaging techniques for fMRI

Inverse imaging (InI) supercharges the sampling rate of traditional functional MRI 10-100 fold at a cost of a moderate reduction in spatial resolution. The technique is inspired by similarities between multi-sensor magnetoencephalography (MEG) and highly parallel radio-frequency (RF) MRI detector arrays. Using presently available 32-channel head coils at 3T, InI can be sampled at 10 Hz and provides about 5-mm cortical spatial resolution with whole-brain coverage. Here we discuss the present applications of InI, as well as potential future challenges and opportunities in further improving its spatiotemporal resolution and sensitivity. InI may become a helpful tool for clinicians and neuroscientists for revealing the complex dynamics of brain functions during task-related and resting states.     

Acute respiratory failure in intensive care units. FINNALI: a prospective cohort study

Objective  To evaluate the incidence, treatment and mortality of acute respiratory failure (ARF) in Finnish intensive care units (ICUs). Study design  Prospective multicentre cohort study. Methods  All adult patients in 25 ICUs were screened for use of invasive or non-invasive ventilatory support during an 8-week period. Patients needing ventilatory support for more than 6 h were included and defined as ARF patients. Risk factors for ARF and details of prior chronic health status were assessed. Ventilatory and concomitant treatments were evaluated and recorded daily throughout the ICU stay. ICU and 90-day mortalities were assessed. Results  A total of 958 (39%) from the 2,473 admitted patients were treated with ventilatory support for more than 6 h. Incidence of ARF, acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) was 149.5, 10.6 and 5.0/100,000 per year, respectively. Ventilatory support was started with non-invasive interfaces in 183 of 958 (19%) patients. Ventilatory modes allowing triggering of spontaneous breaths were preferred (81%). Median tidal volume/predicted body weight was 8.7 (7.6–9.9) ml/kg and plateau pressure 19 (16–23) cmH₂O. The 90-day mortality of ARF was 31%. Conclusions  While the incidence of ARF requiring ventilatory support is higher, the incidence of ALI and ARDS seems to be lower in Finland than previously reported in other countries. Tidal volumes are higher than recommended in the concept of lung protective strategy. However, restriction of peak airway pressure was used in the majority of ARF patients. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. This article is discussed in the editorial available at: doi:.     

Brain electrical activity during food presentation in obese binge‐eating women

Binge‐eating (BE) subjects have shown altered brain activity at frontal regions during food presentation. The aim of this study was to examine the frontal brain electrical activity in obese BE women (n = 12) and in obese women without BE (non‐BE, n = 13). Brain electrical activity was measured using a quantitative electroencephalography during a resting state (eyes‐closed) and when the subjects focused (eyes‐open) their attention on a picture of a landscape (control experiment) or on a meal (food experiment). The BE showed greater frontal beta activity (14–20 Hz) than the non‐BE in both the eyes‐closed (on average 52%) and the eyes‐open situations and independently of the stimulus (control experiment: 57% and food experiment: 71%). No significant differences between the groups were found in alpha, delta or theta amplitudes. Increased beta activity correlated positively with the disinhibition factor of the Three‐Factor Eating Questionnaire. Thus, our results suggest that elevated frontal beta activity may be a marker of dysfunctional disinhibition–inhibition mechanism, which could make the obese BE women more vulnerable or sensitive to food and the environmental cues.     

Sentinel lymph node biopsy or elective neck dissection for patients with oral squamous cell carcinoma?

Sentinel lymph node biopsy (SNB) seems to be a promising method for staging clinically N0 neck in patients with oral squamous cell carcinoma (OSCC). In the present study, SNB was performed on 46 patients having elective neck dissection (END; six bilateral dissections) for T1–T3N0 OSCC. Sentinel lymph nodes (SLN) were first examined according to only slightly modified standard histopathologic protocol including sections at 1–2 mm intervals and H&E staining. SLN that appeared false negative (i.e. metastatic non-SLN without metastasis in a SLN) after the initial histopathologic examination were further assessed by step sectioning at 150 μm intervals and immunohistochemistry. Of the 47 neck sides with at least one SLN identified, nine contained metastasis in nine patients. After the initial histopathologic examination, SLNs were negative for malignant cells in four out of the nine metastatic neck sides. In one neck side, two metastatic SLNs were detected after the additional meticulous histopathologic work-up of the initially false negative SLNs. Therefore, in three neck sides the SLN did not contain metastasis although there was a metastasis in a non-SLN. In all these three cases with a false negative SLN, only one SLN had been identified. The sensitivity of the method (employing extensive histopathologic work-up) for detection of occult cervical metastasis was 67% (6/9 neck sides). The sensitivity of SNB for detection of occult metastasis seems to be poor in cases where only one SLN can be identified. The results of this study do not entitle us to entirely replace END by SNB in patients with OSCC.     

Reduced serotonin transporter binding in binge eating women

RATIONALE: There is evidence that abnormalities in brain dopamine, norepinephrine and serotonin metabolism may play an important role in binge eating. Serotonin-active antidepressant drugs have also been found to decrease binge eating. OBJECTIVE: We investigated serotonin transporter binding in obese binge-eating women. Eleven obese binge-eating and seven obese control women participated in the study. The subjects were not taking any medication known to affect serotonin (5-HT) transporters. METHODS: We used single-photon emission tomography (SPECT) with the radioligand 123I-labelled nor-beta-CIT, which specifically labels 5-HT transporters. RESULTS: Obese binge-eating women showed significantly decreased 5-HT transporter binding in the mid-brain compared with obese controls (2.1 +/- 0.5 versus 2.9 +/- 0.5, respectively). CONCLUSIONS: SPECT imaging with a ligand specific for 5-HT transporters can be used to assess altered serotonin transporter binding in the living human brain. The results tentatively suggest that 5-HT transporter binding is decreased in binge-eating women.     

Enhanced magnetic auditory steady-state response in early Alzheimer's disease.

OBJECTIVE: Previous studies have reported abnormalities in both spontaneous and evoked electromagnetic brain activity in Alzheimer's disease (AD). We studied the auditory steady-state response (SSR) which represents the net effect of entrained background activity and superimposed cortical evoked responses, in AD patients and healthy controls. METHODS: Whole-head magnetoencephalography (MEG) was used to measure SSR to monaural 40-Hz stimulation in AD patients and age-matched controls. Equivalent current dipoles (ECD) of the SSR were modeled in each hemisphere, and source amplitudes were compared between the two groups using time-varying ECD models. RESULTS: Our results indicate that the SSR is significantly increased in AD patients with mild to moderate cognitive deterioration in comparison with healthy elderly subjects. CONCLUSIONS: Goal-directed functioning requires optimization of inhibitory and excitatory inputs in the cortex, allowing the adaptation of responsiveness to repetitive stimulation with low relevance. The present results suggest that this balance is impaired in AD, manifesting itself in decreased inhibition in cortical auditory processing and impaired adaptation of the stimulus-locked activity, probably due to abnormalities in cholinergic modulation. SIGNIFICANCE: MEG appears to be a sensitive tool to detect abnormalities of auditory processing already in early stages of AD.     

Factors that predict morbidity and mortality in patients with perforated peptic ulcers.

BACKGROUND: The demographic changes of perforated peptic ulcer disease were assessed in a well-defined population in northern Finland. The high mortality from perforated peptic ulcer underlines the importance of risk stratification, and clinical variables and three scoring systems were therefore tested for their ability to predict the probability of morbidity and mortality. METHODS: Two hundred and eighty patients admitted to a university hospital with peptic ulcer perforation during the 22-year period 1979-2000 were identified using a computer database, and their clinical data were reviewed from the database and patient records. RESULTS: The annual operation rate for ulcer perforation has varied from 2.7/100,000 in 1979 to 6.2 in 1985 and 3.6 in 2000 without any significant changes during the examination period. More operations have been performed for duodenal (157) than for gastric (123) ulcer perforations, but their incidence rates were quite similar at the beginning and the end of the period. Of the clinical variables, two or more associated illnesses, duration of symptoms for more than 24 hours, the amount of abdominal liquid, and low albumin concentration predicted morbidity, while a long duration of symptoms and the amount of abdominal liquid were independent risk factors for mortality. The MPI score correctly predicted 96% of postoperative complications and all the three scores, i.e. the Boey score, the MPI score and the ASA score, were good predictors of mortality. CONCLUSION: The incidence of peptic ulcer perforation has not changed during the 22-year period in northern Finland. All the three scores, i.e. the Boey score, the MPI score and the ASA score, predict mortality in patients with peptic ulcer perforation and are suitable for risk stratification preoperatively in the surgical ward.