酶联免疫吸附试验在结核性脑膜炎诊断中的初步应用

结核性脑膜炎的诊断目前主要依据临床表现、CSF的异常改变、OT试验及X线和细菌学检查。由于疾病早期临床表现和CSF改变往往不典型;OT试验阳性有助于诊断,阴性不能除外结脑;X线仅用于有无合并脑外结核的检查。尽管从CSF中查到结核酶即可确定诊断,但阳性率太低。国内报导涂片阳性约15～30％,培养约30～40     

Intraspecific density-dependent effects on growth and fecundity of <Emphasis Type="Italic">Diplosentis nudus</Emphasis> (Harada, 1938) Pichelin et Cribb, 2001 (Acanthocephala,Cavisomidae)

During June and July of 2007, a total of 130 specimens of the fish Rastrelliger kanagurta Cuvier (Teleostei, Scombridae), ranging between 19–31 cm in total length, were caught in the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt, and examined for infections by acanthocephalans (65 fish/month). Of this number, 29 (22.30%) were slightly or heavily parasitized by the acanthocephalan Diplosentis nudus (Harada, 1938) Pichelin et Cribb, 2001 (Cavisomidae); no other helminth parasites were found in the intestine of R. kanagurta. Twenty-nine infrapopulations of D. nudus, ranging from 23–218 individuals were collected from the infected fishes. These infrapopulations were distributed in a well-defined fundamental niche along the intestine of R. kanagurta, where the distribution of male worms was not random with respect to female worms size and position and suggests that the male-male competition for access to female may be intense and may select for large males. No correlation between fish size and infrapopulation size was observed. Correlations between female-to-male sex ratio and infrapopulation size, numbers of females and their mean lengths, numbers of males and their mean lengths, mean female length and mean male length within infrapopulation were very strong, and clearly suggest that as the infrapopulation size increased, the number of females and their mean lengths decreased and the number of males and their mean lengths increased. Combination of these results strongly suggests density-dependent effects and competition between male worms. The relationship between the mean female length or size and the number of eggs within its pseudocoel was strongly positive; egg production by female worm significantly decreases as the infrapopulation size increases, suggesting density-dependent reduction in female worm fecundity. Tendency for the variability in male testes size was not significant in infrapopulations of D. nudus. All of these results are discussed.     

The use of DIG-labelled cRNA probes for the detection of cymbidium mosaic potexvirus (CymMV) and odontoglossum ringspot tobamovirus (ORSV) in orchids

DIG-labelled sense and antisense cRNA probes were synthesized from cDNA clones of CymMV and ORSV for virus detection in infected plants. A slot-blot hybridization assay was developed using either crude leaf extracts or total RNA from infected leaves. The assay could detect 50 and 250 pg of purified CymMV and ORSV RNA, respectively. As little as 30 mg of Nicotiana benthamiana infected leaves was sufficient to provide positive detection. CymMV and ORSV were detected at 3125 and 625 times dilution of leaf extracts, respectively. The DIG-labelled cRNA probes are stable for more than a year. This method is sensitive, reliable and suitable for large-scale routine testing of plant viruses. By using the two DIG-labelled cRNA probes in situ, CymMV and ORSV were localized in systemically infected leaves and stems of N. benthamiana and orchids.     

Fibrinolytic system of the armadillo <Emphasis Type="Italic">Chaetophractus villosus</Emphasis> (Xenarthra,Dasypodidae)

The fibrinolytic mechanism in the armadillo Chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae) quite unknown until now was studied. Results were compared with those corresponding to healthy adult human beings. Whole blood lysis time and diluted blood lysis time were not detectable in armadillos. Euglobulin clot lysis time and plasminogen activity (Plg) were lower than in healthy humans. We established the presence of the fibrinolytic system in Ch. villosus through the measurement of fibrin fibrinogen degradation products. The activity of the plasminogen activator inhibitor was two to four times greater than in healthy humans. The activity of the alpha 2 anti-plasmin (α2AP) was similar and displaced toward lower values. The Plg/α2AP relation was lower. The results obtained suggest that Ch. villosus has a hypercoagulable and hypofibrinolytic profile. Our findings are not only the first contribution to elucidate the physiology of the fibrinolytic system in Xenarthra but also contribute to develop an animal model for studies in haemostasis and thrombosis.     

Ser80Ile mutation and a concurrent Pro25Leu variant of the <Emphasis Type="Italic">VHL</Emphasis> gene in an extended Hungarian von Hippel-Lindau family

Von Hippel-Lindau disease (VHL) is a rare autosomal dominant disease characterized by development of cystic and tumorous lesions at multiple sites, including the brain, spinal cord, kidneys, adrenals, pancreas, epididymis and eyes. The clinical phenotype results from molecular abnormalities of the VHL tumor suppressor gene, mapped to human chromosome 3p25-26. The VHL gene encodes two functionally active VHL proteins due to the presence of two translational initiation sites separated by 53 codons. The majority of disease-causing mutations have been detected downstream of the second translational initiation site, but there are conflicting data as to whether few mutations located in the first 53 codons, such as the Pro25Leu could have a pathogenic role. In this paper we report a large Hungarian VHL type 2 family consisting of 32 members in whom a disease-causing AGT80AAT (Ser80Ile) c.239G>A, p.Ser80Ile mutation, but not the concurrent CCT25CTT (Pro25Leu) c.74C>T, p.Pro25Leu variant co-segregated with the disease. To our knowledge, the Ser80Ile mutation has not been previously described in VHL type 2 patients with high risk of pheochromocytoma and renal cell cancer. Therefore, this finding represents a novel genotype-phenotype association and VHL kindreds with Ser80Ile mutation will require careful surveillance for pheochromocytoma. We concluded that the Pro25Leu variant is a rare, neutral variant, but the presence such a rare gene variant may make genetic counseling difficult.     

The cellular mechanism of thalamic ponto-geniculo-occipital waves

The cellular mechanisms underlying the genesis of thalamic ponto-geniculo-occipital waves were studied in reserpinized cats under urethane anaesthesia. Simultaneous field potential and intracellular recordings were performed in the lateral geniculate nucleus after acute lesions of retinal and visual cortical inputs. In most relay cells, reserpine-induced ponto-geniculo-occipital waves were associated with a transient depolarization that was often interrupted by a unitary inhibitory postsynaptic potential. The depolarization grew in size with membrane hyperpolarization and was accompanied by an increase in membrane conductance. The inhibitory postsynaptic potential is likely to have resulted from the activation of intrageniculate interneurons since perigeniculate cells were always inhibited during the occurrence of ponto-geniculo-occipital waves. Under reserpine, thalamic ponto-geniculo-occipital waves could also be triggered by peribrachial or auditory stimulation. These evoked ponto-geniculo-occipital waves were associated with intracellular events identical to those occurring spontaneously after reserpine administration. In addition, thalamic spindle oscillations were readily blocked by the occurrence of spontaneous or evoked ponto-geniculo-occipital waves. On the basis of the present results and those already published in the literature, the conclusion is reached that lateral geniculate ponto-geniculo-occipital waves result from a nicotinic activation of relay cells and from a parallel muscarinic inhibition of perigeniculate cells by peribrachial afferents. The functional significance of the ponto-geniculo-occipital activity is discussed on the basis of the antagonistic action of these signals on thalamic oscillations. It is proposed that these signals are the central correlates of orienting reactions elicited by sensory stimuli during waking (the so-called eye movement potentials) and by internally generated drives during paradoxical sleep.     

Hematological reference intervals in argentine lizard <Emphasis Type="Italic">Tupinambis merianae</Emphasis> (Sauria—Teiidae)

In order to establish referential hematological parameters, blood samples were taken from 100 healthy specimens of the Argentine tegu lizard (Tupinambis merianae) by means of venipuncture of ventral coccigeal vein. The determination of red blood cells, leukocyte and thrombocyte count, hematocrit, hemoglobin concentration, hematometric index and differential leukocyte count were performed, and compared with other saurian species. No statistically significant changes were observed as function as sex and age (p > 0.01). During winter, high values of red blood cell counts, hematocrit and hemoglobin were observed (p < 0.01), while in summer significantly increased leukocyte and thrombocyte counts were observed (p < 0.01). The differential leukocyte counts were not affected by the studied factors.     

基于线性调频信号的高帧率超声成像系统

基于有限衍射波束的高帧率超声成像系统能实现快速成像，但由于仅通过一次发射事件成像，信噪比较低，本研究针对该问题提出一种改进方案。它采用合成孔径雷达中所使用的线性调频信号作为激励信号，在接收端则利用线性调频信号的脉冲压缩比等于信号的时间带宽积的特征，将接收信号通过匹配滤波器处理。结果表明该方案不仅能显著提高成像系统的信噪比，改善重构图像的质量，增加成像深度，而且不损失分辨率。