A low copy number cosmid

A low copy number cosmid was constructed by subcloning the pair of cos sites and the kanamycin resistance gene of pcos2EMBL into pGB2. The resulting cosmid, pPR691, has the pSC101 replicon and specifies resistance to kanamycin, spectinomycin, and streptomycin. pPR691 also carries restriction sites suitable for cloning partial Sau3A digests using the strategy of Bates and Swift (P. F. Bates and R. A. Swift, 1983, Gene 26, 137-146). A library of Salmonella typhimurium chromosomal DNA was made using this cosmid and the rfb gene cluster (map position 42) was isolated from this library.     

Ambient Inclusion Trails (AITs) from the Neoproterozoic Gangolihat Formation,Lesser Himalaya,India

Discovery of well-preserved Ambient Inclusion Trails (AITs) is reported for the first time in India from stromatolitic dolomite unit of the Neoproterozoic Gangolihat Formation, Kumaun Lesser Himalaya. AITs are distinct microtubular structures formed by migration of a mineral in a rock substrate. They exhibit several noncrystallographic morphologies such as curved and helical types among others. Mode of field occurrence, association, and petrographic textures suggest that AITs are indigenous to the host rock. Based on the physico-chemical conditions necessary for the formation of AITs, involvement of a biological process is considered for the genesis of AITs in the Gangolihat Formation.     

Immunohistochemical localization of adenosine deaminase complexing protein in intestinal mucosa and in colorectal adenocarcinoma as a marker for tumour cell heterogeneity

Summary Adenosine deaminase complexing protein (ADCP), a dimeric glycoprotein, has been reported to be decreased or deficient in transformed or cancer-derived cell lines, indicating its potential significance as an indicator of malignant transformation. A similar deficiency was reported in total homogenates of tumours of colon, kidney, lung and liver. In previous biochemical studies we failed to confirm the consistent reduction in ADCP concentration in cancer tissues. A possible explanation for our findings was thought to be intercellular heterogeneity in ADCP expression in individual tumour cells. To study ADCP expression in individual cells we developed an immunohistochemical method which was applied to tissue sections. Paraformaldehyde-lysine-periodate (PLP) solution was found to be a suitable fixative. Fixed tissue samples were paraffin-embedded, sectioned and stained for ADCP, using an indirect peroxidase-labelled antibody procedure. The protein was localized in normal colonic mucosa, mainly in the brush border region of the luminal epithelium and in cytoplasmic granules. Intense ADCP immunoreactivity was found also in the basal part of some cells. In cancer cells, three staining patterns were observed: membranous, diffuse cytoplasmic and granular cytoplasmic. The adenocarcinomas exhibited significant intratumour and intertumour heterogeneity in their staining types.Further studies on ADCP expression in colorectal cancer in relation to clinical and histopathological characteristics are warranted in order to fully evaluate the potential significance of ADCP as a cancer associated antigen.     

Influence of zoysiagrass rhizosphere fungal isolates on growth and yield of soybean plants

Among 21 rhizosphere fungi tested, eight sterile fungi and oneTrichoderma isolate (GT2-1) from zoysiagrass rhizosphere promoted the overall growth of soybean varieties when grown in the greenhouse. Out of nine effective isolates, GS7-4, GS8-2, GS8-3, GU23-3 (all sterile fungi) and GT2-1 (Trichoderma sp.) promoted plant growth and increased yield of Toyosuzu (variety 1) significantly, while GS8-3, GS10-1, GS10-2 (sterile fungi), and GT2-1 significantly caused plant growth promotion and yield increase of Kitamusume (variety 2). Among these efficient isolates, GS8-3 and GS10-2 induced considerable and consistent increases in length, biomass and yield of plants of varieties 1 and 2, respectively. In the field, however, only GS8-3 and GU23-3 among seven selected isolates, induced consistent and significant increases in plant growth and yield of varieties 1 and 2, while the ability of other isolates decreased. The plant growth promotion by these isolates in the field followed a similar trend to that in the greenhouse, but the effect was less marked. Some isolates which were effective in the greenhouse were less effective in the field. The degree of growth promotion by different isolates depended on the variety of soybean. The nutrient condition of soils used in experiments also seemed to play a vital role, since notable growth promotion by these isolates was observed in nutrient-depleted soil.The author is grateful to Ministry of Education, Science and Culture, Japan, for financial assistance.     

Rapid detection of hypoxanthine-guanine phosphoribosyltransferase on cellogel

Zusammenfassung 541 Serumproben von nichtverwandten Deutschen aus dem Kölner Raum wurden auf ihre Pt- und C3-Typen untersucht. Bei 537 Seren fand sich eine Überein-stimmung der Pt A-Typen mit den C3 F-Typen, der Pt AB-Typen mit den C3 FS-Typen und der Pt B-Typen mit C3 S-Typen. Die C3-Varianten F0.65S, F0.6S, F0.5S wurden als Pt AB bestimmt, die C3-Variante F0.55S wurde als Pt B bestimmt. Die Frage der Vergleichbarkeit der Systeme sowie die Untersuchungsmethoden werden diskutiert.

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Comparative studies on posttransferrin (Pt) and C3 in the polymorphism of the third component of human complement

Summary Sera of 541 unrelated Germans from the Cologne area were examined for their Pt and C3 types. There was correspondence between Pt A and C3 F, Pt AB and C3 FS, and Pt B and C3 S in 537 sera. C3 variants F0.65S, F0.6S, F0.5S were determined as Pt AB, C3 F0.55S was determined as Pt B. The question of possible identity and the methods used are discussed.

     

Naphthalene oxygenase fromCorynebacterium renale: Characterisation and mechanism of oxygenation

The formation ofcis-l,2,-dihydroxy-l,2,-dihydronaphthalene from naphthalene by naphthalene oxygenase, purified fromCorynebacterium renale ATCC 15075, was demonstrated to involve oxidation of a mol NADH and consumption of one mol oxygen. The enzyme contains one g-atom Fe²⁺ and one FAD. Catalase inhibited product formation and H2O2 could substitute for NADH in the reaction. Superoxide dismutase inhibited enzyme activity when either NADH or H₂O₂ was present; the generation of superoxide anion on addition of NADH to the enzyme, in the absence of naphthalene, was detected by the nitro blue tetrazolium reduction method. Hydroxyl radical scavengers, ethanol, mannitol and sodium benzoate, inhibited product formation when either NADH or H₂O₂ was present. Electron spin resonance studies, under aerobic conditions, indicated that iron of the enzyme underwent valence changes during the course of the reaction     

Inactivation by chloroquine of alpha-galactosidase in cultured human skin fibroblasts

When human skin fibroblasts are cultured in the presence of chloroquine or NH₄Cl there is a decrease in the intracellular level of lysosomal hydrolases and a concomitant increase in the extracellular activity as compared with cells grown in the absence of a base (cf [18]). In a medium with 25 μM chloroquine or 5 mM NH₄Cl, the decrease in the intracellular activity of β-hexosaminidase, arylsulphatase and β-glucuronidase is 10–40% after 1 day. A similar decrease in α-galactosidase activity is observed in cells grown in the presence of 5 mM NH₄Cl. However, in the presence of 25 μM chloroquine, the intracellular activity of α-galactosidase decreases by 80–90% within 6 h. The inactivation is irreversible. After removal of the chloroquine and further culture of the cells in chloroquine-free medium, α-galactosidase activity gradually increases due to de novo synthesis. The turnover time of α-galactosidase was calculated to be 1.9 days. Inactivation of α-galactosidase also occurs when homogenates are incubated with chloroquine, but the concentration of the base required for maximum inactivation is at least three orders of magnitude higher than that which must be present in the medium of intact cells to obtain the same effect.