Intrachloroplast Localization of 65Zn and 63Ni in a Zn-tolerant Plant, Ocimum basilicum Benth

Intrachloroplast localization studies of ⁶⁵Zn and ⁶³Ni weremade in a Zn-tolerant plant Ocimum basilicum var. purpurascensBenth. in order to investigate the mechanism and specificityof metal tolerance. The isotopes were supplied in solution tothe roots 14 d before fractionation. It was observed that ⁶⁵Znactivity was comparatively greater in the chloroplast envelopemembranes and stroma than the ⁶³Ni; and ⁶³Ni was largely foundin the lamellar and stroma fractions. Further analysis of lamellaerevealed that photosystem II (PS II) particles were richer inradioactivity than photosystem I (PS I) particles. The photochemicalevents of photosynthesis were less affected in Zn-treated plantsthan in the Ni-treated plants. The changed levels of the electrontransport chain intermediates including cytochromes, plastocyaninand ferredoxin provide supporting evidence for the localizationstudies. The activity of carbonic anhydrase, a zinc metalloprotein,was increased in Zn-treated plants with increase in nutrientZn concentration, indicating the binding of zinc to a proteinmoiety in the chloroplasts.     

Cytohistological correlation as a measure of quality assurance of a cytology laboratory

Cytohistological correlation as a measure of quality assurance of a cytology laboratory In a hospital-based cytology screening programme for the early detection of preinvasive lesions of the uterine cervix, 166 women with abnormal smears (human papillomavirus (HPV) changes, cervical intraepithelial neoplasia (CIN) and invasive carcinoma) were referred to the central colposcopy clinic between January 1989 and December 1991. The colposcopist (V.S.) was able to take a direct biopsy in 156 cases. In the remaining 10 cases, biopsy could not be taken because of unsatisfactory colposcopy. A cytohistological correlation was obtained in 121/156 (77.5%) cases, and the remaining 35 cases showed a disparity in diagnosis. These were reviewed by one of us (P.S.) and the reasons for underdiagnosis/false negatives and overdiagnosis/false-positive results were analysed. It was found that sampling error was the cause of false negativity and underdiagnosis in most cases, while interpretative errors resulted in the overdiagnosis and false-positive smears. The reasons for interpretative errors were studied in detail. Les corrélations cyto-histologiques comme mesure de l'assurance qualité dans un laboratoire de cytologie Dans le cadre d'un programme hospitalier de dépistage précoce des lésions précurseurs et des lésions invasives du col utérin, 166 femmes ayant un frottis anormal (lésions virales à HPV, CIN, carcinome infiltrant) ont été vues dans le service central de colposcopie entre janvier 1989 et décembre 1991. Dans 156 cas, le colposcopiste (VS) a pu réaliser une biopsie. Dans les 10 cas restants, la colposcopie n'était pas satisfaisante et la biopsie n'a pas été pratiquée. Une corrélation cyto-histologique a pu être établie dans 121 cas sur 156 (77, 5%) avec, dans 35 cas, constatation d'une discordance diagnostique. Ces cas ont été revus par l'un de nous (PS) et les raisons de cette sous-évaluation diagnostique/faux-négatifs et de surévaluation diagnostique/faux-positifs, ont été analysées. Cette analyse montre que le prélèvement est à l'origine des faux-négatifs et de la sous-évaluation diagnostique dans la majorité des cas, alors que l'erreur d'interprétation est responsable de la surévaluation diagnostique et des faux-positifs. Les sources d'erreur d'interprétation ont été étudiées dans le détail. Die Korrelation zwischen Zytologie und Histologie als Massnahme der Qualitatssicherung eines zytologischen Labors Im Rahmen des Screeningprogramms eines Krankenhauses wurden 166 Frauen mit auffälligen Befunden (HPV, CIN oder invasive Karzinome) zwischen Januar 1989 und Dezember 1991 einer zentralen Kolposkopieklinik überwiesen. Biopsien konnten in 156 Fällen gewonnen werden, während das kolposkopische Bild dies in 10 Fällen nicht rechtfertigte. Übereinstimmung zwischen Zytologie und Histologie wurde in 121/156 (77,5%) erzielt. Abweichungen ergaben sich in 35 Fällen, die genau analysiert wurden. Entnahmefehler verursachten die meisten falsch negativen und unterbewerteten Fälle, während falsch positive und zu hoch bewertete Fälle auf Interpretationsfehlern beruhten. Diese wurden genau studiert.     

Photo-Acoustic Spectroscopy of Pubescent Leaves

The optical absorption spectra of pubescent (hairy) and depubescisedleaves of Blumea oxydonta DC and Gomphrena decumbens Jacq weretaken using the relatively new technique of photo-acoustic spectroscopy.The pubescent leaf gave a higher photo-acoustic intensity thanthe depubescised leaf. The adaptive significance of pubescenceto the leaf is discussed. Key words: Photo-acoustic spcctroscopy, pubescence     

Minimal Defined Media for Vegetative Growth of the Acrasian Polysphondylium pallidum WS-320*

SYNOPSIS. Polysphondylium pallidum WS-320 grows indefinitely as vegetative amebae in a liquid medium where (a) substrates comprise sucrose, glycerol, acetate, lactate, citrate, and glutamate; (b) essential nutrients (riboflavin, lysine, glycine, and possibly several other amino acids that may be essential) are supplied. The growth thus supported (2 × 10⁶ cells/ml) is more than doubled by provision of a mixture of crude fatty acids, an acid hydrolysate of casein supplemented with B vitamins, purines, pyrimidines, and fat-soluble antioxidants.     

Chemical Examination of Viable and Non-Viable Rice Seeds

A chemical examination has revealed four phenolic compounds in nonviable rice seeds (Oryza sativa L.). Their inhibitory bioactivity in the wheat coleoptile extension bioassay and the absence of these components in viable seeds have confirmed the relation of the phenolics with nonviability of the seeds. The compounds isolated from nonviable rice seeds were Kaempferol-4′-methyl ether, Kaempferol, quercetin and caffeic acid as identified on the basis of physical and chemical evidences.