Alcohol-related ERP changes recorded from different modalities: a topographic analysis

BACKGROUND: There is controversy in the literature regarding the relationship between event-related-potential (ERP) abnormalities in abstinent alcoholics and stimulus-processing modality (i.e., visual versus auditory). The first purpose of this study was to address questions about whether ERP abnormalities observed in alcoholics are modality specific. The second purpose was to employ current source density (CSD) analyses to investigate topographic differences between alcoholics and controls within each modality. METHODS: Data were collected from 30 sober male alcoholics and 39 normal males in a typical auditory oddball task and in a visual oddball paradigm with novel stimuli, with an extensive set of 61 scalp electrodes. Visual and quantitative assessment of CSD maps as well as analyses of variances on both raw and normalized ERP data were performed. RESULTS: Positive findings were limited to the N1 and P3 components. The visual N1 amplitude was significantly smaller in alcoholics than in controls at the parietal region; no significant group differences in N1 were found in the auditory modality. Alcoholics had widespread reductions in P3 amplitudes in both modalities compared with controls, although in the frontal region this effect was partially due to the influence of age. These P3 reductions in alcoholics were statistically more pronounced in the posterior compared with the anterior regions regardless of modality. Topographically, sources in CSD maps were weaker in alcoholics than in controls; in the frontal and central regions, the weakness was more pronounced in the auditory modality but, in parietal and occipital regions, it was more pronounced in the visual modality. CONCLUSIONS: The results suggest that, in abstinent alcoholics, abnormalities in auditory ERPs may be localized to more anterior sources, while abnormalities in visual ERPs may be localized to more posterior sources. ERP topographic features are more sensitive than amplitude measurements in assessing alcoholic-related modality effects.     

Effect of laser-dimpled titanium surfaces on attachment of epithelial-like cells and fibroblasts

PURPOSE

The objective of this study was to conduct an in vitro comparative evaluation of polished and laserdimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti.

MATERIALS AND METHODS

Forty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had 5-µm dimples at 10-µm intervals, and SM30 (n=16) had 5-µm dimples at 25-µm intervals in a 2 × 4 mm² area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences.

RESULTS

The adhesion strength of epithelial cells was higher on Ti surfaces with 5-µm laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins.

CONCLUSION

These findings demonstrate that laser dimpling may contribute to improving the periimplant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment.     

视神经减压术中蝶窦外侧壁的结构辨认和保护

目的探讨鼻内镜下视神经减压术中如何准确找到和开放视神经管,避免毗邻重要结构损伤,并介绍术中大动脉出血的紧急处理。方法确诊为外伤性视神经病的患者3 0例,术前明确视神经、颈内动脉、眼动脉的位置和损伤情况,定位彼此间的解剖关系。术中以术前的影像学资料为依据初步定位视神经的位置,采取直接开放视神经管或沿眶尖向后逐渐开放视神经管的方式减压视神经,同时注意毗邻解剖结构的保护。结果 30例均准确定位视神经管和视神经;28例顺利完成视神经减压;2例眼动脉假性动脉瘤出血,经及时窦腔填塞止血,终止视神经减压手术;无手术所致的视神经、颈内动脉、眼动脉和海绵窦损伤等严重并发症。结论以影像学资料为依据选择恰当的方法开放视神经管;注意蝶窦外侧壁结构的保护,并掌握紧急处理和预防颈内动脉和眼动脉出血的方法;是防止严重并发症和保证手术顺利完成的关键。     

眼前节处理系统个体化切削治疗复杂屈光不正

目的 评价眼前节处理系统个体化切削治疗复杂屈光不正的临床疗效.方法 对32例( 63眼)复杂屈光不正患者应用眼前节处理系统的地形图引导,进行个体化切削,于术前、术后1周、1个月、3个月进行裸眼视力、最佳矫正视力、眼压、眼前节分析系统的角膜曲率、角膜厚度及角膜地形图检查,以及主观视觉质量调查.结果 术后裸眼视力均优于术前最佳矫正视力,术前角膜散光(2.46±0.36)D,术后残留(0.28 ±0.14)D:角膜切削量节省10％左右,有效增加了切削后角膜的厚度;主观视觉质量调查无不良反应;术后角膜地形图检查无偏中心现象.结论 眼前节处理系统个体化切削治疗复杂屈光不正安全、有效.     

Topography of the pelvic autonomic nerves in human fetuses between 21-29 weeks of gestation

Summary A topographical study concerning the autonomic nerves in the pelvis of human fetuses was performed by investigating 300–600 m thick sections through fetal pelves, impregnated with the epoxy resin E 12 and cut with a diamond wire-saw. In addition the inferior hypogastric plexus of a 26-week old male fetus was dissected by lateral approach. In 21–29-week old fetuses the pelvic autonomic nerves are relatively thick. Thus the nerves stand out well against surrounding structures and their topographical relationships can exactly be determined. The inferior hypogastric plexus of 21–29-week old fetuses is situated on a curved line between the rectum and the ventrally adjacent structure. It constitutes a rectangular plate, which cannot be subdivided into individual plexuses for the different pelvic organs. The fetal plexus is heavily ganglionated. Large ganglia, forming the so-called ganglion of Frankenhaeuser, are found in the female as well as in the male fetus. In the fetal pelvis the connective tissue compartments are still clearly arranged, because adipose tissue is not yet abundant. The greater part of the inferior hypogastric plexus is situated exactly at the border between a dense visceral tissue medially and a loose parietal tissue laterally. The plexus does not share a common connective tissue cover with the pelvic blood vessels. In fetuses the inferior hypogastric plexus lies in close vicinity to serveral organs, but the pelvic floor is the only region where the nerves can hardly be separated from the surrounding structures.     

Development and topography of auditory event-related potentials (ERPs): Mismatch and processing negativity in individuals 8–22 years of age

How do event related potentials (ERPs) reflecting auditory processing develop across adolescence? Such development was described for five ERP components in four groups of 11 healthy participants with mean ages of 10, 14, 17, and 21 years. Data from 19 sites during diffuse (passive) and focused (discrimination) attention in a three-tone oddball were analyzed to see how ERP loci varied with age for tone type attention condition, and for four types of difference waves reflecting nontarget and target comparison. Age interacted with site for most components. P1 loci sensitive to rare tones moved postoriorly and N1 loci lost their right bias in early puberty. The P2 loci did not move anterior to Council adulthood N2 amplitude, sensative to attention condition, developed a frontal focus by 17 years. Right biased P3 loci moved lo the midline with focused attention similarly in all age groups. Difference waves developed in three stages; In 10-years-old participants early deflection (<150 ms) were diffusely distributed; in mid adolescent participants, the main frontal negative component (150-300 ms) became well formed and lost an earlier right bias: and for participants 17 years old and older, the late positive complex developed a right bias in target-derived waves. Latency decreases for early frontal components were marked in participants 10–14 years old and for later posterior components m participants 14–17 years old. Major developments appeared at the onset of adolescence in early stimulus selection processes and during adolescence in the in the differential use of this information (N2- and P3-like latencies).     

Understanding smell—The olfactory stimulus problem

The main problem with sensory processing is the difficulty in relating sensory input to physiological responses and perception. This is especially problematic at higher levels of processing, where complex cues elicit highly specific responses. In olfaction, this relationship is particularly obfuscated by the difficulty of characterizing stimulus statistics and perception. The core questions in olfaction are hence the so-called stimulus problem, which refers to the understanding of the stimulus, and the structure–activity and structure–odor relationships, which refer to the molecular basis of smell. It is widely accepted that the recognition of odorants by receptors is governed by the detection of physico-chemical properties and that the physical space is highly complex. Not surprisingly, ideas differ about how odor stimuli should be classified and about the very nature of information that the brain extracts from odors. Even though there are many measures for smell, there is none that accurately describes all aspects of it. Here, we summarize recent developments in the understanding of olfaction. We argue that an approach to olfactory function where information processing is emphasized could contribute to a high degree to our understanding of smell as a perceptual phenomenon emerging from neural computations. Further, we argue that combined analysis of the stimulus, biology, physiology, and behavior and perception can provide new insights into olfactory function. We hope that the reader can use this review as a competent guide and overview of research activities in olfactory physiology, psychophysics, computation, and psychology. We propose avenues for research, particularly in the systematic characterization of receptive fields and of perception.