Persistent aggregates in apheresis platelet concentrates are commonly collected from donors with a history of aggregate donation.

Platelet apheresis sometimes causes persistent aggregates (PA). This study (n = 211) shows that changing the apheresis settings to reach fixed product volumes instead of yields does not influence PA incidence, even though PA products on average contain more platelets than controls. Furthermore, logistic regression was used to model if PA can be predicted on the basis of certain predonation parameters. PA donation history was the only parameter retained, proving a strong determinant of predictability [AUC = 0.735 (SE = 0.022)]. Consequently, donations from a donor with previous PA history are 7.8 times more likely to contain PA than from a donor without preceding history.

Evaluation of the intercept oral specimen collection device with HIV assays versus paired serum/plasma specimens.

Oral fluid has many advantages over blood-based techniques: it is less invasive, eliminates the occupational risk associated with needle stick accidents and collection can be self-administrated. Each individual test is packaged with a corresponding collection device. This study tested the suitability of the Intercept Oral Specimen Collection Device for different HIV diagnostic tests: three different rapid HIV tests and two adapted ELISAs, which were evaluated and compared with a gold standard on blood. In addition a total IgG quantification was performed to demonstrate the quality of the specimen. HIV antibodies were detected with a sensitivity of 100%, 99.3%, 98.6%, 100% and 95.7% for, DPP, OraQuick, Aware, Genscreen and Vironostika respectively using the Intercept Collection Device. Respective specificities were 100%, 100%, 99.3%, 97.3% and 100%.

Light-sensitive brain pathways and aging.

Notwithstanding its effects on the classical visual system allowing image formation, light acts upon several non-image-forming (NIF) functions including body temperature, hormonal secretions, sleep-wake cycle, alertness, and cognitive performance. Studies have shown that NIF functions are maximally sensitive to blue wavelengths (460-480 nm), in comparison to longer light wavelengths. Higher blue light sensitivity has been reported for melatonin suppression, pupillary constriction, vigilance, and performance improvement but also for modulation of cognitive brain functions. Studies investigating acute stimulating effects of light on brain activity during the execution of cognitive tasks have suggested that brain activations progress from subcortical regions involved in alertness, such as the thalamus, the hypothalamus, and the brainstem, before reaching cortical regions associated with the ongoing task. In the course of aging, lower blue light sensitivity of some NIF functions has been reported. Here, we first describe neural pathways underlying effects of light on NIF functions and we discuss eye and cerebral mechanisms associated with aging which may affect NIF light sensitivity. Thereafter, we report results of investigations on pupillary constriction and cognitive brain sensitivity to light in the course of aging. Whereas the impact of light on cognitive brain responses appears to decrease substantially, pupillary constriction seems to remain more intact over the lifespan. Altogether, these results demonstrate that aging research should take into account the diversity of the pathways underlying the effects of light on specific NIF functions which may explain their differences in light sensitivity.

Evaluation of 6 years of confidential unit exclusion at the Belgian Red Cross Flanders Blood Service.

BACKGROUND AND OBJECTIVES: The effectiveness of the confidential unit exclusion (CUE) as a safety measure to the blood supply is debated. We therefore investigated the usefulness of CUE in our donor population. METHODS: Data of CUE use, donor deferrals due to different degrees of sexual or blood exposure and data of confirmed positive transfusion-transmissible infection (TTI) markers were analyzed for the study period January 1, 2004 to December 31, 2009. RESULTS: The CUE user tended to be of young age, male and first time donor whereas the CUE non-responder was more likely to be older, first time donor without a clear sex predilection. CUE had low sensitivity (0·33%) and low positive predictive value (0·02%) in detecting TTI marker positive donations. Of 46 incident cases, one donor designated his pre-conversion donation as CUE positive. 29·6% of the donors deferred due to reported sex or intravenous drug related risk factors on the donor history questionnaire had ticked 'I do practice risk behavior' on the CUE form. Deferrals for all sexual or blood-blood contact related risk factors were 19·2 times higher among CUE positive donors than among CUE negative donors (95% CI, 18·5-19·9). CONCLUSION: Although CUE use is associated with higher rates of TTI risk, CUE has low efficiency to detect window period donations. Moreover, misuse results in a significant loss of units. Our data indicate a low risk perception among donors, hence efforts should focus on improving donor knowledge of and on donor's responsibility to disclose TTI risk.

Fast and slow spindle involvement in the consolidation of a new motor sequence.

This study aimed to determine the distinct contribution of slow (11-13 Hz) and fast (13-15 Hz) spindles in the consolidation process of a motor sequence learning task (MSL). Young subjects (n = 12) were trained on both a finger MSL task and a control (CTRL) condition, which were administered one week apart in a counterbalanced order. Subjects were asked to practice the MSL or CTRL task in the evening (approximately 9:00 p.m.) and their performance was retested on the same task 12h later (approximately 9:00 a.m.). Polysomnographic (PSG) recordings were performed during the night following training on either task, and an automatic algorithm was used to detect fast and slow spindles and to quantify their characteristics (i.e., density, amplitude, and duration). Statistical analyses revealed higher fast (but not slow) spindle density after training on the MSL than after practice of the CTRL task. The increase in fast spindle density on the MSL task correlated positively with overnight performance gains on the MSL task and with difference in performance gain between the MSL and CTRL tasks. Together, these results suggest that fast sleep spindles help activate the cerebral network involved in overnight MSL consolidation, while slow spindles do not appear to play a role in this mnemonic process.

Spectral quality of light modulates emotional brain responses in humans.

Light therapy can be an effective treatment for mood disorders, suggesting that light is able to affect mood state in the long term. As a first step to understand this effect, we hypothesized that light might also acutely influence emotion and tested whether short exposures to light modulate emotional brain responses. During functional magnetic resonance imaging, 17 healthy volunteers listened to emotional and neutral vocal stimuli while being exposed to alternating 40-s periods of blue or green ambient light. Blue (relative to green) light increased responses to emotional stimuli in the voice area of the temporal cortex and in the hippocampus. During emotional processing, the functional connectivity between the voice area, the amygdala, and the hypothalamus was selectively enhanced in the context of blue illumination, which shows that responses to emotional stimulation in the hypothalamus and amygdala are influenced by both the decoding of vocal information in the voice area and the spectral quality of ambient light. These results demonstrate the acute influence of light and its spectral quality on emotional brain processing and identify a unique network merging affective and ambient light information.

Hemodynamic cerebral correlates of sleep spindles during human non-rapid eye movement sleep.

In humans, some evidence suggests that there are two different types of spindles during sleep, which differ by their scalp topography and possibly some aspects of their regulation. To test for the existence of two different spindle types, we characterized the activity associated with slow (11-13 Hz) and fast (13-15 Hz) spindles, identified as discrete events during non-rapid eye movement sleep, in non-sleep-deprived human volunteers, using simultaneous electroencephalography and functional MRI. An activation pattern common to both spindle types involved the thalami, paralimbic areas (anterior cingulate and insular cortices), and superior temporal gyri. No thalamic difference was detected in the direct comparison between slow and fast spindles although some thalamic areas were preferentially activated in relation to either spindle type. Beyond the common activation pattern, the increases in cortical activity differed significantly between the two spindle types. Slow spindles were associated with increased activity in the superior frontal gyrus. In contrast, fast spindles recruited a set of cortical regions involved in sensorimotor processing, as well as the mesial frontal cortex and hippocampus. The recruitment of partially segregated cortical networks for slow and fast spindles further supports the existence of two spindle types during human non-rapid eye movement sleep, with potentially different functional significance.

Wavelength-dependent modulation of brain responses to a working memory task by daytime light exposure.

In addition to classical visual effects, light elicits nonvisual brain responses, which profoundly influence physiology and behavior. These effects are mediated in part by melanopsin-expressing light-sensitive ganglion cells that, in contrast to the classical photopic system that is maximally sensitive to green light (550 nm), is very sensitive to blue light (470-480 nm). At present, there is no evidence that blue light exposure is effective in modulating nonvisual brain activity related to complex cognitive tasks. Using functional magnetic resonance imaging, we show that, while participants perform an auditory working memory task, a short (18 min) daytime exposure to blue (470 nm) or green (550 nm) monochromatic light (3 x 10(13) photons/cm2/s) differentially modulates regional brain responses. Blue light typically enhanced brain responses or at least prevented the decline otherwise observed following green light exposure in frontal and parietal cortices implicated in working memory, and in the thalamus involved in the modulation of cognition by arousal. Our results imply that monochromatic light can affect cognitive functions almost instantaneously and suggest that these effects are mediated by a melanopsin-based photoreceptor system.

Lingual foramina on the mandibular midline revisited: a macroanatomical study.

The purpose of the present study was to determine the incidence, size, location, course, and content of the foramina and bony canals located on the lingual side of the mandibular midline. Fifty dry human mandibles were morphometrically analyzed by measuring the distances of these midline foramina from the mandibular base and the dimensions of these foramina and their bony canals. In addition, macro- and microanatomical dissection was performed on 12 intact cadaver mandibles. The macroanatomic midline foramina were classified into superior and inferior genial spinal foramina according to their vertical location with respect to the genial spines. This study showed that out of 50 dry mandibles, 49 (98%) had at least one midline lingual foramen; only one lacked a true midline foramen. Evaluation of the microanatomical dissections indicated a clear neurovascular bundle in both superior and inferior genial spinal foramina and canals. For the superior canal, the content was found to derive from the lingual artery and the lingual nerve. For the inferior canal, however, the arterial origin was submental and/or sublingual, while the innervation derived from a branch of the mylohyoid nerve. In conclusion, different kinds of lingual foramina have been identified according to their location. The superior and inferior genial spinal foramina have different neurovascular contents, determined by their anatomical location above or below the genial spines.

The left intraparietal sulcus and verbal short-term memory: focus of attention or serial order?

One of the most consistently activated regions during verbal short-term memory (STM) tasks is the left intraparietal sulcus (IPS). However, its precise role remains a matter of debate. While some authors consider the IPS to be a specific store for serial order information, other data suggest that it serves a more general function of attentional focalization. In the current fMRI experiment, we investigated these two hypotheses by presenting different verbal STM conditions that probed recognition for word identity or word order and by assessing functional connectivity of the left IPS with distant brain areas. If the IPS has a role of attentional focalization, then it should be involved in both order and item conditions, but it should be connected to different brain regions, depending on the neural substrates involved in processing the different types of information (order versus phonological/orthographic) to be remembered in the item and order STM conditions. We observed that the left IPS was activated in both order and item STM conditions but for different reasons: during order STM, the left IPS was functionally connected to serial/temporal order processing areas in the right IPS, premotor and cerebellar cortices, while during item STM, the left IPS was connected to phonological and orthographic processing areas in the superior temporal and fusiform gyri. Our data support a position considering that the left IPS acts as an attentional modulator of distant neural networks which themselves are specialized in processing order or language representations. More generally, they strengthen attention-based accounts of verbal STM.

Microanatomical and histological assessment of the content of superior genial spinal foramen and its bony canal.

OBJECTIVES: To assess histologically the true content of the superior genial spinal foramen and to match these findings to the microanatomical canal content observed using high-resolution magnetic resonance images of the same region. METHODS: Ten human mandibular specimens were imaged using a 9.4 Tesla MRI unit. Afterwards, eight specimens were decalcified, embedded in paraffin and serially sectioned (7 microm) for histological examination; the remaining two were embedded in methylmethacrylate and sectioned (50-60 microm). All sections were examined using routine light microscopy to inspect the superior genial spinal foramen region and its content. RESULTS: Histological observations of the superior genial spinal foramen confirmed the presence of a well-defined neurovascular bundle, with branches of the lingual nerve and lingual artery. The canal had an average diameter exceeding 1 mm and could thus be considered significant. CONCLUSIONS: The present study confirms the existence of a true superior genial spinal foramen's bony canal with neural and blood vessel content. These findings imply that surgical procedures should consider a proper preoperative assessment of the neurovascular trajectory of the superior genial spinal foramen.

Intracranial facial nerve rhabdomyoma. Case report.

Nerve rhabdomyomas are exceedingly rare benign tumors of the peripheral nerves consisting of well-differentiated striated muscle fibers admixed with parental nerve fibers. Only one case of intracranial nerve rhabdomyoma has been described, which affected the trigeminal nerve. This report presents the detailed neuropathological description of a nerve rhabdomyoma arising in the schwannian portion of the facial nerve root in a 41-year-old Caucasian man. The nerve fibers were arranged chaotically as in a traumatic neuroma. Because of the intimate intermingling of this slow-growing tumor with the parental nerve fibers, complete excision should be avoided.