揭阳市1460例吸毒者HIV及梅毒监测结果分析

目的了解揭阳市吸毒人员艾滋病病毒（HIV）及梅毒的感染状况及相关危险因素。方法采用统一的调查表．对2006年新进入戒毒所的吸毒人员进行面对面的问卷调查，同时对每一个调查对象采用一次性注射器采集静脉血3～5ml进行HIV和梅毒抗体检测。结果共监测1460名吸毒者，HIV阳性率为0．48％，梅毒感染率为10．55％：有43．84％注射毒品行为，注射毒品的吸毒者中有38．60％承认曾与他人共用注射器或针头：28．22％吸毒者承认曾通过钱或毒品交易与他人发生过性行为，16．26％的吸毒者每次与他人发生性关系时都使用安全套。结论揭阳市吸毒人群的HIV感染率较低，但存在高危行为，应加强干预等工作，阻止艾滋病由高危人群向一般人群传播。     

颈交感神经干离断对妊高征大鼠胎盘NO含量及NOS基因表达的影响

目的：观察颈交感神经干离断（TCST）对妊高征（PIH）大鼠胎盘一氧化氮（NO）含量及内皮型一氧化氮合酶(eNOS)和诱导型一氧化氮合酶(iNOS)基因表达的影响。方法:妊娠大鼠随机分5组,每组15只。对照组（C）：自妊娠14 d开始皮下注射生理盐水至孕20 d;妊高征1组、2组（H1、H2）：自妊娠14 d开始皮下注射L-NAME分别为125 mg·kg-1·d-1和62.5 mg·kg-1·d-1，至孕20 d；手术组（O）：妊娠第14 d行右TCST，余同B1;假手术组（S）：妊娠第14 d行右颈交感神经干分离，但不离断，余同 H1。孕21 d剖宫取仔。观察孕鼠血压、尿蛋白，胎鼠的大小、体重、畸形率、死亡率，胎盘NO含量、eNOS mRNA、iNOS mRNA表达。结果:（1） 血压、尿蛋白除基础值外H1、H2组各时点值明显高于C组(P<0.01)；H2组明显低于H1组(P<0.01)；O组与C组相比差异无显著(P>0.05)。（2）胎鼠体重、大小 H1、H2组明显低于C组（P<0.01）；H1组明显低于H2组（P<0.05，P<0.01）;O组与C组相比差异无显著(P>0.05)。死亡率、畸形率变化与上述指标相反。（3）胎盘NO含量及eNOS mRNA、iNOS mRNA表达 H1、H2组明显低于C组（P<0.01）；H1组明显低于H2组（P<0.01，P<0.05）;O组明显高于H1组 （P<0.01），且与C组比无显著差异（P>0.05）。结论：TCST可保护孕鼠免受妊高征的影响，可能与其具有改善孕鼠胎盘组织eNOS mRNA、iNOS mRNA表达和NO含量有关。     

Neural dynamics in cortex-striatum co-cultures-II. Spatiotemporal characteristics of neuronal activity

Neural dynamics in organotypic cortex-striatum co-cultures grown for three to six weeks under conditions of dopamine deficiency are described. Single neuron activities were recorded intra- and extracellularly, and spatiotemporal spreading of population activity was mapped using voltage-sensitive dyes. The temporal properties of spike firing were characterized by interspike interval histograms, autocorrelation and crosscorrelation.

Cortical pyramidal neurons (n = 40) showed irregular firing with a weak tendency to burst or to oscillate. Crosscorrelations revealed strong near-coincident firing and synaptic interactions. Disinhibition was a notable feature in a strongly firing cortical interneuron. Cortical activity spread in the co-culture, thus inducing an overall, homogeneous depolarization in the striatal part. Striatal cells were divided into principal cells and type I and II secondary cells. Principal cells (n = 40) were similar to those reported previously in vivo. Spiking activity ranged from irregular spiking at very low rates to episodic bursting, with an average burst duration of 1 s. Interspike intervals were single-peaked. Intracellular recordings revealed characteristic, long-lasting subthreshold depolarizations (“enabled state”) that were shortened by local muscarinic receptor blockade. During prolonged time periods in the “enabled state”, locally applied bicuculline induced strong firing in most principal neurons. Striatal secondary type I neurons (n = 25) showed high spiking rates, single- and double-peaked interval histograms and low-threshold, short-lasting stereotyped bursting activity and occasional rhythmic bursting. The firing of these neurons was increased by bicuculline. Crosscorrelations showed synchronization of these cells with principal cell activity. Secondary type II neurons (n = 15) revealed tonic, irregular firing patterns similar to cortical neurons, except with occasional firing in doublet spikes.

We conclude that under conditions of dopamine deficiency in corticostriatal co-cultures (i) the cortex induces the “enabled” state and typical bursting mode in striatal principal neurons; (ii) principal neurons are strongly inhibited during the “enabled” state; (iii) muscarinic activity, presumably from tonically active striatal cholinergic interneurons, stabilizes the “enabled” state; (iv) striatal GABAergic interneurons receive synaptic inhibition and take part in synchronized activity among striatal principal cells. Our results favor the view of the striatum as a lateral inhibition network.     

Monitoring of basophil activation using CD63 and CCR3 in allergy to muscle relaxant drugs

Allergic or pseudoallergic reactions that occur during anesthesia have been increasing for the last few years. To date, the diagnosis of allergy to muscle relaxants remains difficult. In this respect, we developed a flow cytometric method for the study of drug-induced basophil degranulation using CD63 and CCR3. Fifty patients who developed clinical features evocative of allergic reactions immediately after induction of anesthesia were included and classified into two groups. Group 1 (n = 39) comprised true allergic patients, who developed typical signs of shock associated to positive skin testing. Group 2 (n = 11) consisted of patients whose clinical history was not typical and skin testing was negative or nonconclusive. Seventeen control subjects were also studied in this report. We compared data from flow cytometry to skin tests, specific IgE, and histamine release results. Flow cytometry showed a sensitivity of 54%, while that of specific IgE was similar, at 62%. Interestingly, when considering the sensitivity of IgE + CD63 for diagnosis, we reached a sensitivity value of 80%. Of 15 negative results for specific IgE, we found 7 positive CD63 tests, while histamine release gave positive results in only 2 cases. Furthermore, the CD63 protocol showed good specificity (100%). We conclude that our flow cytometry protocol is a promising tool in allergy diagnosis since it is specific and complementary to specific IgE detection.     

Frequent expression of the multi-drug resistance-associated protein BCRP/MXR/ABCP/ABCG2 in human tumours detected by the BXP-21 monoclonal antibody in paraffin-embedded material

The expression and cellular localization of angiotensin II (Ang II) and AT(1) receptor proteins were examined in the normal human prostate and benign prostatic hyperplasia (BPH) by immunohistochemistry. In the normal prostate, Ang II immunoreactivity was localized to the basal layer of the epithelium and AT(1) receptor immunostaining was found predominantly on stromal smooth muscle and also on vascular smooth muscle of prostatic blood vessels. Ang II immunoreactivity was markedly increased in hyperplastic acini in BPH compared with acini in the normal prostate (normal: 7.4+/-0.2%, n=5 vs. BPH: 22.7+/-1.9%, n=5, p<0.001). However, AT(1) receptor immunoreactivity was significantly decreased in BPH compared with the normal prostate [normal: 16.4+/-2.2%, n=4 vs. BPH: 9.4+/-1.3%, n=5, p<0.05 (p=0.025)]. The present study demonstrates the presence of Ang II peptide in the basal layer of the epithelium and AT(1) receptors on stromal smooth muscle, suggesting that Ang II may mediate paracrine functions on cellular growth and smooth muscle tone in the human prostate. Furthermore, AT(1) receptor down-regulation in BPH may be due to receptor hyperstimulation by increased local levels of Ang II in BPH. These data extend previous findings in support of the novel concept that overactivity of the renin-angiotensin system (RAS) may be involved in the pathophysiology of BPH.     

Enhanced responsiveness of human extravisual areas to photic stimulation in patients with severely reduced vision

Lesions in the primary visual cortex induce severe loss of visual perception. Depending on the size of the lesion, the visual field might be affected by small scotomas, hemianopia, or complete loss of vision (cortical blindness). In many cases, the whole visual field of the patient is affected by the lesion, but diffuse light-dark discrimination remains (residual rudimentary vision, RRV). In other cases, a sparing of a few degrees can be found (severely reduced vision, SRV).In a follow-up study, we mapped visually induced cerebral activation of three subjects with SRV using functional magnetic resonance imaging. We were especially interested in the visual areas that would be activated if subjects could perceive the stimulus consciously although information flow from V1 to higher visual areas was strongly reduced or virtually absent. Because subjects were only able to discriminate strong light from darkness, we used goggles flashing intense red light at a frequency of 3 Hz for full visual field stimulation. Besides reduced activation in V1, we found activation in the parietal cortex, the frontal eye fields (FEF), and the supplementary eye fields (SEF). In all patients, FEF activation was pronounced in the right hemisphere. These patterns were never seen in healthy volunteers. In a patient who recovered completely, we observed that extrastriate activation disappeared in parallel with the visual field restitution. This result suggests that damage to the primary visual cortex changes the responsiveness of parietal and extravisual frontal areas in patients with SRV. This unexpected result might be explained by increased stimulus-related activation of attention-related networks.     

Structural evidence for counter-current flow in proximal tubules versus pertitubular capillaries in the rat kidney. Evaluation of the counter-current mechanism between the proximal convoluted tubules and the peritubular capillaries in the rat nephron

BACKGROUND: In spite of the very high exchange of water and solutes between the proximal tubules and the peritubular capillaries, very little is known about flow directions in these two interrelated structures. We therefore developed a morphological technique suitable for the quantitative evaluation of a counter-current system between the proximal convoluted tubules and the peritubular capillaries in rat renal cortex. METHODS: In male pentothal-anesthetized Wistar rats (body weight 200-250 g), India ink was injected into the aorta above the renal arteries, followed by instant freezing of the right kidney in isopentane at -165 degrees C, and subsequent freeze-substitution in alcohol. In microscopic slides from kidneys in which only 20-55% of the cortical peritubular capillary loops was filled with ink--representing the arterial end of the capillaries--and in which the proximal tubular segmentation could be identified in PAS-stained sections, the segments of the convoluted proximal tubules were quantitatively compared with regard to the presence of ink-stained and unstained peritubular capillaries in nephrons from the whole renal cortex. RESULTS: In the microscopic specimens of the five animals used both the loops from the first segment (P1) of the proximal convoluted tubule and those of the second segment (P2) were systematically packed closely together, the transitional segment (P1-2) being interposed between the groups. Around the loops of P1, 8%+/-2% of the capillaries was stained with India ink. In contrast, surrounding the P2 loops 67%+/-5% of the capillaries contained ink, significantly exceeding that for P1 (p<0.01). CONCLUSION: Throughout the rat renal cortex, the most proximal fraction of the peritubular capillaries surrounds the second segments of the proximal convoluted tubules, while the first tubular segments are surrounded by the more distal fraction of the peritubular capillaries. Consequently, the flows in the peritubular capillaries and in the proximal convoluted tubules in the rat renal cortex are systematically arranged as a counter-current system. This feature was previously identified only in superficial nephrons.     

心率变异性在反映心脏自主神经损伤和重构中的应用

缺血预适应和急性心肌梗死恢复期都会出现心脏自主神经的变化,心率变异性（HRV）是无创测量心自主神经活动的重要方法.研究自主神经的变化能为疾病机理和临床用药研究提供理论基础,所以监测预适应和心梗后的HRV有着重要意义.本文综述了预适应和心梗恢复期在HRV上的体现,并将HRV的变化与生理生化证据相联系,分析了缺血预适应对自主神经的保护作用和心梗后用HRV检测自主神经恢复的可行性.同时还对心率变异性今后的研究方向做了展望.     

放疗计划系统网络体系的设计与实现

设计并建立一套连接医学影像采集设备(如CTM、RIP、ET等)、放疗计划系统(TPS)及医用加速器等大型设备的的放射治疗网络体系工作环境,更充分地发挥局域网络在放射治疗中的作用。在现有大型医疗设备、TPS及局域网环境的基础上,提出两种具有代表性的TPS网络体系解决方案,并结合各自的特点及实际应用情况对其进行了分析和比较。实践证明,放疗计划系统网络体系的建设推进了放射治疗全过程的数字化、网络化,在更大范围内实现了医疗信息资源的共享,在更大程度上发挥了TPS在肿瘤治疗过程中的作用。     

A Computer Reconstruction of the Entire Coronary Arterial Tree Based on Detailed Morphometric Data

A rigorous analysis of blood flow must be based on the branching pattern and vascular geometry of the full vascular circuit of interest. It is experimentally difficult to reconstruct the entire vascular circuit of any organ because of the enormity of the vessels. The objective of the present study was to develop a novel method for the reconstruction of the full coronary vascular tree from partial measurements. Our method includes the use of data on those parts of the tree that are measured to extrapolate the data on those parts that are missing. Specifically, a two-step approach was employed in the reconstruction of the entire coronary arterial tree down to the capillary level. Vessels > 40 μm were reconstructed from cast data while vessels < 40 μm were reconstructed from histological data. The cast data were reconstructed one-bifurcation at a time while histological data were reconstructed one-sub-tree at a time by “cutting” and “pasting” of data from measured to missing vessels. The reconstruction algorithm yielded a full arterial tree down to the first capillary bifurcation with 1.9, 2.04 and 1.15 million vessel segments for the right coronary artery (RCA), left anterior descending (LAD) and left circumflex (LCx) trees, respectively. The node-to-node connectivity along with the diameter and length of every vessel segment was determined. Once the full tree was reconstructed, we automated the assignment of order numbers, according to the diameter-defined Strahler system, to every vessel segment in the tree. Consequently, the diameters, lengths, number of vessels, segments-per-element ratio, connectivity and longitudinal matrices were determined for every order number. The present model establishes a morphological foundation for future analysis of blood flow in the coronary circulation.