Fiber optic probe cytometer

An optical fiber probe is used to both excite and collect fluorescence from a suspension of cells. The configuration of the probe is such that one or a few cells are sensed at a time, with a convenient cell concentration. With fluorescently labeled antibodies to cellular antigens, the fiber optic cytometer is able to identify the presence of a specific set of cells with high sensitivity.     

Characterization of hemolytic bacteria in subgingival plaque

Three-quarters of the patients with periodontal diseases surveyed in this study had one or more distinct types of hemolytic bacteria in their subgingival plaque. Twelve different species of bacteria were identified, belonging to five genera (Actinomyces, Streptococcus, Staphylococcus, Prevotella, and Actinobacillus). Nine hemolytic isolates, consisting of four Prevotella denticola strains, two Actinomyces naeslundii genospecies 2 strains, and one each of P. melaninogenica, Streptococcus constellatus, and A. naeslundii genospecies 1 strains were characterized. Incorporation of pronase into blood agar medium inhibited hemolysis by all of the isolates, suggesting a proteinaceous component for each of their hemolysins. With one exception, hemolysin production appeared to be regulated by the concentration of environmental iron: exogenous hemin was found to inhibit hemolysin production, and the iron scavenging compound, 2,2′-dipyridyl, was found to promote hemolysin production by all of the strains except for the S. constellatus isolate. Genomic libraries of each of the hemolytic plaque isolates were prepared in Escherichia coli using pBR322. Hemolytic clones were isolated on blood agar medium containing ampicillin at frequencies ranging from 1–6.7 × 10^?4. Extensive restriction mapping revealed regions of homology in the case of clones derived from three P. denticola strains isolated from the same subject. Two of the P. denticola-derived clones were virtually identical throughout the entirety of their > 5 Kb inserts. The clone derived from the third strain showed good homology to the other two within a 1.3 Kb region, but the flanking DNA showed no homology even though all three P. denticola isolates were shown to be clonally related by ribotyping. The results indicate that hemolytic bacteria are frequently recovered from active disease sites of subjects with periodontal diseases. The hemolytic phenotype appears to be restricted to a small proportion of the total number of species normally resident in subgingival plaque. Restriction mapping suggested that a variety of hemolysin genes may be involved and that, at least in certain cases, they may be on mobile genetic elements.     

海马类药材的分子遗传标记鉴定研究

应用古DNA研究技术从5种海马药材中提取DNA,用PCR技术扩增约450bp的12SrRNA基因片段和约490 bp的细胞色素b基因片段。对扩增产物进行了限制性片段长度多态性(RFLP)分析和DNA序列分析。用RFLP分析方法可以鉴别2种海马,用DNA序列分析方法得到的分子遗传标记可以鉴别所有5种海马。对其它动物类药材的鉴定有一定参考价值。     

两输入两输出补偿跟踪系统辨识

本文讨论了基于直接最小二乘辩识方法的两输入两输出闭环系统的可辩识性条件,对人控两输入两输出补偿跟踪系统的实验及参数估计方法进行了讨论,同时给出参数估计的广义最小二乘算法公式。     

Sickle cell anemia as a syndrome: a review of diagnostic features.

Sickle cell (SS) disease is a complex of various genetic conditions. In some, homozygosity for the beta S gene may be present alone or in combination with the heterozygous or homozygous alpha-thalassemia-2 condition. Such combinations might ameliorate the clinical and hematological condition of the patient. The same may be true for the high levels of Hb F and F-cells observed in many Hb S homozygotes. Howeever, the chemical heterogeneity of Hb F appears not to be related to the clinical status of the Hb S homozygote. Combinations of a Hb S heterozygosity with a heterozygosity for a Hb D-type of variant, for either one of two types of beta-thalassemia, two types of alpha beta- thalassemia, and five types of HPFH are discussed, and data are compared with those obtained for Hb S homozygotes. The use of advanced laboratory procedures and family studies is often necessary for an accurate diagnosis.     

Autoradiographic localization of muscarinic agonist binding sites in the rat central nervous system with (+)-cis-[H]methyldioxolane

(+)-cis-[³H]Methyldioxolane ((+)-[³H]CD), a potent muscarinic agonist, was used to label high-affinity agonist states of muscarinic receptors in thin tissue sections of the rat central nervous system. Light microscopic autoradiography of atropine-sensitive (+)-[³H]CD binding sites revealed regions of dense labeling (superior colliculus, inferior colliculus, lateral geniculate body, hypoglossal (XII) nucleus, facial (VII) nucleus, tractus diagonalis) and regions of sparse labeling (hippocampus, dentate gyrus). The inverse regional correlation between high-affinity (+)-[³H]CD states and binding sites for the muscarinic antagonists [³H]pirenzepine (r = −0.79) and (-)-[³H]quinuclidinyl benzilate (r = −0.30) underscores potentially important differences between agonist and antagonist binding to CNS tissue slices.     

Cutaneous vasculitis and cutaneous vasculopathies

Cutaneous involvement may occur with virtually all syndromes of vasculitis. This can occur primarily as a dermatologic disorder or as a manifestation of a potentially life threatening systemic vasculitis. In this review article, classification, clinical manifestations, pathogenesis and therapy of cutaneous vasculitis will be discussed. Disorders which are primarily vascular in origin but lack a well defined inflammatory phase, referred to as ‘vasculopathies’ will also be discussed.     

煤短接触液化产品的荧光光谱鉴定

本文提出了以甲醇作溶剂用荧光光谱分析煤短接触液化产品的方法。对煤的短接触液化产品用不同极性的溶剂洗提得到9个级分,从9个级分中鉴定出25种组分。为了与煤焦油比较,用同样的方法和操作程序测定了煤焦油,鉴定出28个组分。本文还用液相色谱分析测定了煤短接触液化产品的氯仿洗提级分,所得结果与荧光光谱分析所得结果一致,证实了该方法的可靠性。     

Identification of a dextropropoxyphene metabolite by gas chromatography—mass spectrometry

Summary Gas chromatography in combination with high and low resolution mass spectrometry has been used for identification of metabolites of dextropropoxyphene isolated from liver extract.

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Zusammenfassung Für die Identifikation der Metaboliten von Dextropropoxyphen aus Leberextrakten wurde eine Kombination der Gaschromatographie mit der hoch und niedrig auflösenden Massenspektrometrie angewandt.