A freshwater mussel survey was conducted in Indian Creek, Tazewell County, Virginia, during 1996 and 1997. Fifteen species were identified, including the federally endangered <i>Epioblasma florentina walkeri<i>, <i>Villosa perpurpurea</i>, and <i>Quadrula cylindrica strigillata</i>. Population assessments and fish host identifications were completed for the tan riffleshell and purple bean populations. Host fish for <i>E. f. walkeri</i> were limited to the banded and mottled sculpin, greenside darter, redline darter, fantail darter, and snubnose darter. Fish hosts identified for <i>V. perpurpurea</i> also were the banded and mottled sculpin, greenside darter, and redline darter. Size class structure of the tan riffleshell population ranged from 19.9 to 53.3 mm, with the population estimated at nearly 700 individuals with a density of 0.015/m². Size class structure of the purple bean population ranged from 22.9 to 66.7 mm, with the population estimated at only 70 individuals with a density of 0.002/m². Host fish also were identified for <i>Dromus dromas</i> and <i>Lemiox rimosus</i>. The fantail darter was identified as a host for <i>D. dromas</i>, with the snubnose darter serving as a host for <i>L. rimosus</i>. Additional percids were implicated as hosts for both mussel species. A molecular genetic key for identifying host fishes of the upper Clinch River also was constructed. The key was constructed through the analysis of restriction fragment length polymorphisms from amplified regions of mussel DNA. Thirty-six unionid species were incorporated into the key. No host fishes were identified due to an unsolved problem with amplifying DNA from glochidia collected from wild fish. / Master of Science

Die Frage nach adäquaten mikrobiologischen und molekulargenetischen Methoden, um die Kolonisation des Respirationstrakts von Mukoviszidose-Patienten mit Pseudomonas aeruginosa nachzuweisen und zu charakterisieren, wird kontrovers diskutiert. Von 38 klinisch stabilen Patienten mit cystischer Fibrose (CF) wurden sequentiell im Abstand von 18 Monaten Proben aus Rachenabstrich, Sputum und Bronchiallavage (BAL) entnommen und bezüglich Pseudomonas-Nachweis untersucht. Die Pseudomonas-Stämme wurden mittels Random Amplified Polymorphic DNA (RAPD)-Analyse und Pulsfeld-Gelelektrophorese (PFGE) von DNA-Makrorestriktionsfragmenten typisiert und bezüglich der Frage nach genetisch divergierenden Isolaten innerhalb des selben Individuums sowie nach möglichen longitudinalen genetischen Veränderungen evaluiert. Sensitivität, negative und positive prädiktive Werte und Spezifität, um eine P. aeruginosa-Besiedlung zu erkennen, waren 36%, 74%, 83% und 96% im Falle der Kulturen aus dem Oropharynx von nicht-expektorierenden Patienten und 92%, 94%, 100% und 100% für Sputumkulturen von expektorierenden Probanden. RAPD-Analyse und PFGE waren in der Lage, zwischen unterschiedlichen Pseudomonas-Stämmen zu diskriminieren, wobei nur die DNA-Makrorestriktion zwischen Subtypen unterscheiden konnte. Die Genotypen der Pseudomonas-Isolate aus Rachenabstrich und Sputum divergierten in 55% und 40% zu den Isolaten der BAL. Longitudinale Variationen des Genotyps wurden in 62% der Fälle beobachtet, die Hälfte davon war nur mittels bronchoskopisch gewonnener Proben erkennbar. Zusammengefasst besitzen Sputumproben bezüglich des Pseudomonas-Nachweises dieselbe Wertigkeit wie Kulturen aus der BAL, während Rachenabstriche in einer frühen Krankheitsphase für die Charakterisierung der bakteriellen Flora des unteren Respirationstrakts wenig geeignet sind. Die Methode der DNA-Makrorestriktion kann als zuverlässige Technik für epidemiologische Untersuchungen empfohlen werden. Unterschiedliche Genotypen innerhalb desselben Individuums und longitudinale genetische Alterationen sind häufig, jedoch unter Umständen nur bronchoskopisch nachweisbar. / There is controversy about adequate specimen to detect and characterise colonisation of cystic fibrosis (CF) airways by Pseudomonas aeruginosa. Oropharyngeal, sputum and bronchoalveolar lavage (BAL) samples were evaluated sequentially from 38 stable CF patients for the detection of P. aeruginosa. Pseudomonas strains were typed by random amplified polymorphic DNA (RAPD) analysis and pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. The occurrence of genetically different isolates within the same host and longitudinal variations in the genotype during repeated examinations was assessed. Sensitivity, negative and positive predictive values and specificity to detect P. aeruginosa were 36%, 74%, 83% and 96% for oropharyngeal cultures in non-expectorating patients and 92%, 94%, 100% and 100% for sputum cultures from expectorating patients, respectively. RAPD analysis and PFGE were suitable to characterize P. aeruginosa CF isolates, although only DNA macrorestriction was able to distinguish between identical and closely related strains. Genotypes of Pseudomonas isolates recovered from oropharyngeal swabs and sputum differed to the strains recovered by bronchoscopy in 55% and 40%, respectively. In 62% longitudinal variations in the genotype occurred. Half of these alterations were only detectable from bronchoscopically obtained samples. In conclusion, sputum samples have the same value as specimens from BAL to detect P. aeruginosa colonisation, whereas cultures from the oropharynx are not suitable for characterising the bacterial conditions in the CF lungs in an early disease state. DNA macrorestriction is recommended as an excellent tool for epidemiological investigations. Different genotypes within the same host and longitudinal genetic alterations are common and may be detectable in the BAL fluid exclusively.

Part I. The aldosterone synthase gene (CYP11B2) polymorphism T-344C in blood pressure and left ventricular hypertrophy. BACKGROUND: Aldosterone is a key cardovascular hormone, it significantly influences volume, pressure and electrolyte balance. Aldosterone plays an important role in development of left ventricular (LV) hypertrophy and myocardial fibrosis. The aldosterone synthase gene (CYP11B2) is an important candidate gene region in essential hypertension. DESIGN AND METHODS: We assessed the influence of the T-344C polymorphism of aldosterone synthase - the rate-limiting enzyme in aldosterone biosynthesis - on the structure of the left ventricle in young normotensive men. The population included 113 normotensive mid-European Caucasian men aged 18-40 years (mean 27 +/- 5 years). We also studied the association of -344T/C polymorphism of the CYP11B2 gene with the presence and severity of hypertension in 369 individuals, of whom 213 were hypertensive patients (139 controlled hypertensive, 74 resistant hypertensive) and 156 were healthy normotensive subjects. The genotype was assessed using polymerase chain reaction with subsequent cleavage with restriction enzyme HAEIII (restriction fragment length polymorphism method) and visualization with ethidium bromide. Plasma renin activity (PRA) and plasma...