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Chemical Examination of the Roots of \(Aristolochiα\) \(Indicα\), Linn. Part I.&nbsp

An immunoscreening approach was used to isolate a strongly positive cDNA clone from an Entamoeba histolytica HK-9 cDNA expression library in the phage vector lambda ZAP-II. The 1.85-kb cDNA insert was found to be truncated and encoded the cysteine-rich, immunodominant domain of the antigenic 170-kDa subunit of the amebal galactose-N-acetylgalactosamine binding lectin. This domain was expressed as a glutathione S-transferase fusion protein in Escherichia coli. Inclusion bodies of the recombinant protein were solubilized with Sarkosyl, and the protein was enriched from the crude bacterial extract by thiol-affinity chromatography. The recombinant protein was used to develop a rapid, sensitive, and specific avidin-biotin microtiter enzyme-linked immunosorbent assay (ELISA) for invasive amebiasis. Sera from 38 individuals suffering from invasive amebiasis, 12 individuals with noninvasive amebiasis, 44 individuals with other infections, and 27 healthy subjects were screened by the recombinant antigen-based ELISA. The sensitivity and specificity of the assay were 90.4 and 94.3%, respectively, which correlated well with those of an ELISA developed with crude amebal antigen (r = 0.94; P < 0.0001), as well as with those of a commercially available serodiagnostic ELISA (r = 0.92; P < 0.0001). Thus, the bacterially expressed recombinant lectin can replace the crude amebal extract as an antigen in the serodiagnosis of invasive amebiasis by using avidin-biotin microtiter ELISA.

Die Degradationsprodukte, die sich bei der Hydrolyse der Purine, der Pyrimidine und der Nukleinsauren bilden, werden mittels runder Filterpapierscheiben chromatographisch untersucht. Adenine, Nukleinsauren und Adeninverbindungen zeigen bei einer Saurehydrolyse ausser einem Band, das den Platz des Glycin einnimmt, noch ein weiteres Band. Dieses Band ist versuchsweise als 4(5)-amino-5(4)-imidazol Carboxamidin charakterisiert worden. Die Bedeutung dieser Ergebnisse fur die quantitative Analyse der Nukleinsauren und Adeninverbindungen wird in der vorliegenden Arbeit erortert.

THE diazotizable amine which accumulated in cultures of Escherichia coli during sulphonamide bacteriostasis has been isolated and its identity with 4-amino 5-imidazole carboxamide has been established1,2. Evidence to show that this compound was not merely a product of aberrant metabolism but a normal precursor of purines has been obtained3 and its role in purine biosynthesis is well established4. Recently, it was demonstrated that the carboxamide was rapidly utilized in rat liver homogenates and preparations from actively growing tissues5,6. The present report deals with the preliminary experiments carried out to assess the role of this compound as a potential precursor of purines in plants. Resting, as well as germinating, seeds of Phaseolus radiatus (green gram) were used in this investigation.