V—EEG与SPECT联合应用在顽固性癫痫术前致痫灶定位中的价值

目的：探讨视频脑电图（V—EEG）与单光子发射计算机断层扫描（SPECT）联合应用在顽固性癫痫术前致痂灶定位中的价值。方法：对103例顽固性癫痫患者,在MRI扫描的基础上,术前行V—EEG和SPECT检查,联合定位致痫灶,通过术中皮层脑电图（ECoG）检查验证致痫灶定位的准确性。结果：103例患者发作间期V—EEG检查均有异常,85例患者检查过程中有癫痫发作1～3次。SPECT检查异常95例,其中表现为放射性核素稀疏区86例,放射性核素浓聚区9例。术前两者联合定位致痫灶91例,与术中ECoG所确定的致痫灶部位一致者85例,符合率为93．4％。结论：术前V-EEG与SPECT的联合应用可以较准确地定位顽固性癫痫的致痫灶,该法对于MRI无异常的癫痫患者之术前致痫灶定位尤其具有重要意义。     

Prediction of Probabilistic Sleep Distributions Following Travel Across Multiple Time Zones

Study Objectives:

To parameterize and validate a model to estimate average sleep times for long-haul aviation pilots during layovers following travel across multiple time zones. The model equations were based on a weighted distribution of domicile- and local-time sleepers, and included algorithms to account for sleep loss and circadian re-synchronization.

Design:

Sleep times were collected from participants under normal commercial operating conditions using diaries and wrist activity monitors.

Participants:

Participants included a total of 306 long-haul pilots (113 captains, 120 first officers, and 73 second officers).

Measurement and Results:

The model was parameterized based on the average sleep/wake times observed during international flight patterns from Australia to London and Los Angeles (global R² = 0.72). The parameterized model was validated against the average sleep/wake times observed during flight patterns from Australia to London (r² = 0.85), Los Angeles (r² = 0.79), New York (r² = 0.80), and Johannesburg (r² = 0.73). Goodness-of-fit was poorer when the parameterized model equations were used to predict the variance across the sleep/wake cycles of individual pilots (R² = 0.42, 0.35, 0.31, and 0.28 for the validation flight patterns, respectively), in part because of substantial inter-individual variability in sleep timing and duration.

Conclusions:

It is possible to estimate average sleep times during layovers in international patterns with a reasonable degree of accuracy. Models of this type could form the basis of a stand-alone application to estimate the likelihood that a given duty schedule provides pilots, on average, with an adequate opportunity to sleep.

Citation:

Darwent D; Dawson D; Roach GD. Prediction of probabilistic sleep distributions following travel across multiple time zones. SLEEP 2010;33(2):185-195.     

Comparison of Sexual and Drug Use Behaviors Between Female Sex Workers in Tijuana and Ciudad Juarez,Mexico

Female sex workers (FSWs) have been documented to have high rates of sexually transmitted diseases and HIV in many parts of the world. However, little work has been done to characterize the prevalence of these infections along the U.S.–Mexican border, where sexual tourism and culturally sanctioned sex work among nationals is widespread. The objective of this study was to compare differences in background characteristics, HIV risk behaviors, drug use, and sexually transmitted infection/HIV prevalence between FSWs who participated in a behavioral risk intervention in two U.S.–Mexican border cities. Baseline data were collected from March 2004 through September 2005. Data from 295 FSWs were compared between Tijuana and Ciudad (Cd.) Juarez. Among 155 FSWs in Tijuana and 140 in Cd. Juarez, HIV seroprevalence was 4.8% and 4.9%, respectively. FSWs in Cd. Juarez were more likely to test positive for active syphilis (31.3%) compared with Tijuana (11.8%) but did not differ in terms of the prevalence of gonorrhea and chlamydia. FSWs in both sites reported high levels of unprotected sex and use of drugs; however, FSWs in Cd. Juarez were more likely than those in Tijuana to ever have injected drugs (75% vs. 25%, p <.001). Heroin and cocaine use and injection drug use were significantly more common in Cd. Juarez, whereas methamphetamine use was more common in Tijuana. Injection of vitamins was common in both cities. Logistic regression analyses suggested that being younger, working in Cd. Juarez, and using heroin or cocaine were independently associated with active syphilis infection. In Tijuana, methamphetamine use was strongly associated with active syphilis infection. These preliminary results suggest that risk profiles for HIV/sexually transmitted infection among FSWs in these two Mexico–U.S. border cities differ, suggesting a need to tailor interventions to the specific needs in each city.     

Clinicopathological study of invasive ductal carcinoma with large central acellular zone: special reference to magnetic resonance imaging findings

Invasive ductal carcinoma (IDC) with central acellular zone is sometimes encountered, but its clinicopathological features have not yet been fully investigated. The clinicopathological features of 10 resected cases of IDC with a large central acellular zone were investigated. The tumor size ranged from 6 to 28 mm with a mean of 14.3 +/- 6.9 mm. Contrast-enhanced magnetic resonance imaging (MRI) showed a ring-like appearance in the tumor. Sagittal fat-suppressed T2-weighted MRI had very high to intermediate signal intensity in a central area. Histologically, cancer tissue was located in the periphery of the tumor with a ring-like pattern and a large central area was occupied by acellular amorphous tissue that was strongly stained by alcian blue. Lymph vessel permeation was seen in eight cases. Among the tumors with focal enhancement in the central areas >1 cm in diameter on contrast MRI, marked increase of microvessel was observed in the enhanced spot. The mean of p53 and Ki-67 labeling indices was 56.2% and 36.3%, respectively. IDC with a large central acellular zone presenting with characteristic MRI should be noted as a new morphological entity.     

Binocular and monocular/unihemispheric sleep in the domestic chick (<Emphasis Type="Italic">Gallus gallus</Emphasis>) after a moderate sleep deprivation

Binocular (Bin-sleep) and monocular/unihemispheric sleep (Mo-Un sleep) were studied in domestic chicks (Gallus gallus) after an 8 h period of sleep deprivation. Eleven-day-old chicks were divided into three groups: two non-deprived (N-DEP1 and N-DEP2) and one deprived for 8 h (DEP-8H). Deprivation was performed by placing chicks on a treadmill on which they were forced to walk continuously. Sleep behaviour was recorded for 6 h consecutively immediately after the end of sleep deprivation. During the recovery period, sleep-deprived chicks slept for a longer duration, spent significantly more time in binocular sleep and slept for significantly longer episodes that did control chicks. Regarding Mo-Un sleep, sleep deprivation seems to affect the right hemisphere by reducing the number of episodes and the time spent sleeping with the left eye closed. These results suggest that sleep-deprivation significantly influences the pattern of sleep in domestic chicks allowing for a better recovery. The authors state that they have adhered to the “Principles of laboratory animal care” (NIH publication N° 86-23, revised 1985) and to the legal requirements of our country during the present study.     

Delta EEG activity as a marker of dysfunctional linguistic processing in developmental dyslexia

The present study used delta EEG band to test the hypothesis of a cerebral maturational delay and a functional altered cerebral asymmetry for phonological processing in dyslexic children. A group of 14 children with dyslexia and 28 matched controls participated in a linguistic paradigm in which the same words were processed in three tasks: phonological, semantic, and orthographic. Delta amplitude was computed as an index of cortical inhibition in four different phases of word processing. In anterior sites, controls showed left activation (reduced delta) during the phonological task and bilateral activation in the other two tasks. Conversely, children with dyslexia showed greater overall delta amplitude, indexing a cerebral maturation delay and an altered language laterality pattern. In the phonological task they had larger left anterior delta (inhibition of left frontal linguistic locations) and smaller left posterior delta amplitude (activation of left posterior sites silent in controls). Results support the phonological deficit hypothesis of developmental dyslexia and the validity of EEG delta band as functional and clinical measure of language laterality.     

Inversion of contrast polarity abolishes spontaneous preferences for face-like stimuli in newborn chicks

A spontaneous preference for face-like stimuli has been demonstrated in domestic chicks, similar to that shown by human newborns, suggesting evolutionary continuity across species. Inversion of contrast polarity of face-like stimuli abolishes face preferences in human newborns. Here we investigated the effects of contrast polarity inversion and brain lateralization in chicks’ preferences for faces. In Experiment 1 face-naïve chicks were tested with a negative face obtained from a stimulus that elicited preferential approach in previous research. As in human newborns, reversal of contrast polarity abolished face-preferences. Experiments 2, 3 and 5 investigated the effect of adding a pupil-like dot within the inner features of the negative and of positive stimuli (a manipulation that re-established face-preference in human newborns). Chicks reacted to this by avoiding the face stimulus. In Experiments 4 and 6 we found that the preference expressed by chicks having only their left eye (right hemisphere) in use changed according to contrast polarity, whereas it remained unaffected in chicks having their right eye in use. Thus, in domestic chicks, as in human beings, a stimulus is perceived as face-like only if it presents the correct luminance pattern expected for a face under natural top-lit illumination and the right hemisphere seems to play a crucial role in this kind of social orienting responses.     

Premotor and occipital theta asymmetries as discriminators of memory- and stimulus-guided tasks

The saccadic paradigm has been used to investigate specific cortical networks involving visuospatial attention. We examined whether asymmetry in theta and beta band differentiates the role of the hemispheres during the execution of two different prosacadic conditions: a fixed condition, where the stimulus was presented at the same location; and a random condition, where the stimulus was unpredictable. Twelve healthy volunteers (3 male; mean age: 26.25) performed the task while their brain activity pattern was recorded using quantitative electroencephalography. We did not find any significant difference for beta, slow- and fast-alpha frequencies for the pairs of electrodes analyzed. The results for theta band showed a superiority of the left hemisphere in the frontal region when responding to the random condition on the right, which is related to the planning and selection of responses, and also a greater activation of the right hemisphere during the random condition, in the occipital region, related to the identification and recognition of patterns. These results indicate that asymmetries in the premotor area and the occipital cortex differentiate memory- and stimulus-driven tasks.