男男性行为人群艾滋病危险行为同伴干预研究

目的 探讨"发起人主导和同伴驱动相结合的行为干预"方法对促进我国男男性行为(MSM)人群安全套使用和降低性伴数的可行性和有效性.方法 在安徽省有同性恋酒吧的合肥、芜湖、阜阳3个城市,通过招募在MSM活动场所有影响的12名MSM作为"发起人",采用同伴网络招募MSM同伴的方法,在MSM人群中招募了218名符合研究条件的干预对象,建立12个干预活动小组.通过培训"发起人",由他们组织实施4个主题干预活动,干预活动为期1个月.通过比较干预前和干预活动结束后2个月干预对象艾滋病病毒和(或)性接触性感染(HIV/STDs)知识水平、安全套使用率、近2个月的性伴数等指标,来评估干预方法的有效性.结果 干预结束后第3个月随访到170名MSM,随访率77.9%.170名干预对象干预前HIV/STDs知识得分为(14.71±2.59)分,干预后为(16.95±1.81)分,经配对t检验,差异有统计学意义(t=-10.647,P＜0.01);干预后,最近2个月拥有女性性伴报告率由17.6%降低为11.2%,经配对x2检验,差异有统计学意义(P＜0.01);最近3次与男性性伴肛交时安全套使用率从干预前的55.3%提高到干预后的65.2%(x2=9.979,P＜0.01);与男性偶然性伴最近3次肛交时安全套使用率从干预前的43.2%提高到干预后的52.2%(x2=5.797,P＜0.05);与男性固定性伴最近3次肛交时安全套使用率从49.1%提高到60.9%(x2=13.082,P＜0.01);干预前,最近1次与男性性伴、男性偶然性伴、男性固定性伴肛交中未使用安全套的报告率分别为41.2%、35.3%和45.3%,干预后分别降低为25.3%、27.1%和31.2%,分别经配对x2检验,差异有统计学意义(P＜0.01、P＜0.05和P＜0.01).通过群组比较分析的方法,比较干预后随访到的170名干预对象与干预前的218名干预对象的上述指标,除最近2个月有女性性伴报告率、最近3次与男性偶然性伴发生肛交行为中安全套使用率和最近1次与男性偶然性伴发生无保护肛交的报告率3个指标变化差异无统计学意义外,其他指标干预前后变化与上述比较结果基本相似.结论 "发起人主导和同伴驱动相结合行为干预"方法,是可以被我国MSM人群接受并能促进MSM人群肛交性行为中使用安全套.     

脑白质纤维成像的基础研究和临床应用新进展

脑白质纤维成像是目前唯一能直观显示脑白质纤维束的非侵入性检查方法，基础是弥散加权威像，基本原理为脑白质水分子弥散的各向异性。应用最多的方法主要有线性延展法和椭球体表示法。在临床方面的应用主要集中在监测脑白质的发育、成熟及生理性老化；观察脑肿瘤与白质纤维束的关系；显示急性中风、炎症、脑外伤病变引起的脑白质改变；显示精神分裂症病入局部神经联合的中断。     

Transport of molecules from nose to brain: Transneuronal anterograde and retrograde labeling in the rat olfactory system by wheat germ agglutinin-horseradish peroxidase applied to the nasal epithelium

Transneuronal anterograde labeling with the conjugate wheat germ agglutinin-horseradish peroxidase (WGA-HRP) has been documented in the mammalian and immature avian visual system [6,14]. Transneuronal retrograde labeling was significant only in the chick [6]. The present study was performed to determine whether transneuronal labeling could be shown in the mammalian olfactory system, whether the phenomenon was robust in adults, and whether transneuronal retrograde transport could label several transmitter-specific centrifugal afferent projections to the olfactory bulb. In addition we wished to learn whether molecules that enter the nasal cavity can undergo transport to brain neurons. Gelfoam implants soaked with 1% WGA-HRP, surgically implanted into the nasal cavity, produced transneuronal labeling patterns that affirmed all of these questions. Transneuronal anterograde transport labeled the appropriate zones in the olfactory bulb and in all second order olfactory targets. In addition, there was transneuronal retrograde labeling of neurons in the olfactory bulb, anterior olfactory nucleus and in transmitter-specific projection neurons from the diagonal band (cholinergic), raphe (serotonergic) and locus coeruleus (noradrenergic). Transneuronal labeling was robust and consistent. The patterns of labeling indicated that transneuronal anterograde and retrograde transport occurred along known, specific circuits in the olfactory system. The present results suggest that nasal epithelial application of WGA-HRP may be a useful tool for assessing regeneration of primary olfactory neurons and the status of central circuitry following regeneration. The method should also facilitate the study of central olfactory connections after surgical or genetic lesions of the olfactory bulb. Finally, these experiments suggest the possibility that inhaled molecules including, possibly substances of abuse, may be transported to, and, possibly, influence the function of neurons in the brain, including some (diagonal band, raphe, locus coeruleus) which have extensive projections to wide areas of the CNS.     

用单纯疱疹病毒I型跨神经元输送对大鼠小脑纤维联系的研究

实验选用ＳＤ大鼠２３只，分别在小脑前、后叶定位定量注射单纯疱疹病毒Ｉ型存涤２－５天或１０天后灌杀取脑切片，经抗ＨＳＶ１血清行组织化学ＡＢＣ法反应。结果显示，免疫阳性神经元呈类似Ｇｏｌｇｉ样染色，胞体和树突标记清晰。注射部位不同或术后动物存活时间不同，其标细胞出现的数量和部位同。１．后叶注射后１天可出现小脑Ｐｕｒｋｉｎｊｅ细胞及缝核群，网状结构，室周灰质，丘脑腹外侧核发现标记细胞。２．前叶注射后３天     

Fluorescent compounds as retrograde tracers compared with horseradish peroxidase (HRP). II. A parametric study in the peripheral motor system of the cat

Fluorescent compounds which are currently used as retrograde tracers were tested in the cat peripheral motor system and compared with horseradish peroxidase (HRP). The tracers were either injected into forelimb muscles or applied to the proximal end of transected forelimb nerves. The remaining muscles of the limb has been carefully denervated. Following intramuscular injection all fluorescent compounds labeled spinal cord motoneurons, the DAPI compounds labeled endothelial cells in addition. In the nerve application mode tracer positive motoneurons were only observed when propidium iodide (PI) and the DAPI compounds were used, whereas bisbenzimide (BB), nuclear yellow (NY) and primuline did not label any cells. The fluorescence of BB labeled motoneurons were predominantly located in the cytoplasma. NY positive motoneurons showed a different localization of the fluorescent label between the different neurons of the same motornucleus: in some neurons it was exclusively located in the nucleus, in others predominantly in the cytoplasma, in the majority in both compartments. The intracellular distribution of the BB and the NY label was independent of the pH of the fixation fluid. The fluorescent tracers labeled the motoneuronal cell columns in their complete rostrocaudal extent and in a position identical to the one obtained with HRP. However, some substances (PI, fast blue) labeled less motoneurons of a motornucleus than did HRP, none of the fluorescent tracers labeled more. The results are discussed under several aspects: use of the investigated fluorescent compounds as single tracers; use of several tracers in the same animal to map collateral projections of one and the same neuron; use of several tracers in the same animal to establish the topographical relation between several independent neuronal populations.     

Efferent connections of the prelimbic (area 32) and the infralimbic (area 25) cortices: an anterograde tracing study in the cat

The projections from the caudal part of the medial frontal cortex, encompassing the prelimbic area (PL) and the infralimbic area (IL) (Brodmann's areas 32 and 25, respectively), were studied in the cat with the anterograde autoradiographic tracing technique. The results indicate that the projection fields of IL, in contrast to those of PL, are restricted almost exclusively to limbic structures. Whereas the major thalamic projections from PL reach the mediodorsal, anteromedial, and ventromedial nuclei, the medial part of the lateral posterior nucleus, and the parataenial and reticular nuclei, and weak projections from this area are directed to the nucleus reuniens and other midline nuclei, the nucleus reuniens is the major thalamic termination field of fibers arising from IL. Cortical areas that are reached by fibers originating in PL and, to a lesser degree, also in IL, include more rostral prefrontal areas (areas 8, 6, and 12), the agranular insular, and the rostral perirhinal cortices. In contrast, cortical areas that are more strongly related to IL include the cingulate, retrosplenial, caudal entorhinal, and perirhinal cortices and the subiculum of the hippocampal formation. Another prominent output of PL concerns projections to an extensive medial part of the caudate nucleus and the ventral striatum, whereas fibers from IL only distribute most ventrally in the striatum. In the amygdaloid complex, fibers from PL were found to reach the basolateral, basomedial, and central nuclei, and fibers from IL to distribute to the medial and central nuclei. PL furthermore projects to the claustrum and the endopiriform nucleus. Other structures in the basal forebrain, including the medial septum, the nuclei of the diagonal band, the preoptic area, and the lateral and dorsal hypothalamus are densely innervated by IL and only sparsely by PL. With respect to more caudal parts of the brainstem, projections from PL and IL appeared to be essentially similar. They reach the ventral tegmental area, the periaqueductal gray, the parabrachial nucleus, and in cases of PL injections were followed as far caudally as the pons.     

Divergence and convergence of thalamocortical projections to premotor and supplementary motor cortex: a multiple tracing study in the macaque monkey

The premotor cortex of macaque monkeys is currently subdivided into at least six different subareas on the basis of structural, hodological and physiological criteria. To determine the degree of divergence/convergence of thalamocortical projections to mesial [supplementary motor area (SMA)-proper and pre-SMA] and lateral (PMd-c, PMd-r, PMv-c and PMv-r) premotor (PM) subareas, quantitative analyses were performed on the distribution of retrograde labelling after multiple tracer injections in the same animal. The results demonstrate that all PM and SMA subareas receive common inputs from several thalamic nuclei, but the relative contribution of these nuclei to thalamocortical projections differs. The largest difference occurs between subareas of SMA, with much greater contribution from the mediodorsal (MD) and area X, and a smaller contribution from the ventral lateral anterior (VLa) and ventral part of the ventral lateral posterior (VLpv) to pre-SMA than to SMA-proper. In PM, differences between subareas are less pronounced; in particular, all receive a significant contribution from MD, the ventral anterior (VApc) and area X. However, there are clear gradients, such as increasing projections from MD to rostral, from VLa and VLpv to caudal, and from dorsal VLp (VLpd) to dorsal premotor subareas. Intralaminar nuclei provide widespread projections to all premotor subareas. The degree of overlap between thalamocortical projections varies among different PM and SMA subareas and different sectors of the thalamus. These variations, which correspond to different origin and topography of thalamocortical projections, are discussed in relation to functional organizations at thalamic and cortical levels.     

Activation and circuitry of uterine-cervix-related neurons in the lumbosacral dorsal root ganglia and spinal cord at parturition

Stimulation of the uterine cervix at parturition activates neural circuits involving primary sensory nerves and supraspinally projecting neurons of the lumbosacral spinal cord, resulting in output of hypothalamic neurohormones. Dorsal root ganglia (DRG) and spinal neurons of these circuits are not well-characterized. The objectives of this study were to detail the activation of DRG and spinal neurons of the L6/S1 levels that are stimulated at late pregnancy, verify hypothalamic projections of activated spinal neurons, and determine whether activated neurons express estrogen receptor-alpha (ERalpha). Expression of phosphorylated cyclic-AMP response element-binding protein (PCREB) and Fos immunohistochemistry were used to "mark" activated DRG and spinal neurons, respectively. Retrograde tracing identified uterine-cervix-related and spinohypothalamic neurons. Baseline PCREB expression in the DRG increased during pregnancy and peaked during the last trimester. Some PCREB-expressing neurons contained retrograde tracer identifying them as cervix-related neurons. Fos-expressing neurons were few in spinal cords of nonpregnant and day 22 pregnant rats but were numerous in parturient animals. Some Fos-expressing neurons located in the dorsal half of the spinal cord contained retrograde tracer identifying them as spinohypothalamic neurons. Some DRG neurons expressing PCREB also expressed ERalpha, and some spinal neurons activated at parturition projected axons to the hypothalamus and expressed ERalpha. These results indicate that DRG and spinal cord neurons are activated at parturition; that those in the spinal cord are present in areas involved in autonomic and sensory processing; that some spinal neurons project axons to the hypothalamus, ostensibly part of a neuroendocrine reflex; and that sensory and spinal neurons can respond to estrogens. Moreover, some activated sensory neurons may be involved in the animal's perception of labor pain.