Isolation of antibodies to steroid hormones by affinity chromatography on antigen-linked sepharose: An efficient electrophoretic elution procedure

An electrophoretic elution procedure of antibodies retained on affinity columns is described. It afforded a 60% recovery of the binding activity of a high affinity (Ka ～ 10¹⁰ M^?1) antiserum to 5α-dihydrotestosterone retained on antigen-linked Sepharose 4B affinity columns. These purified unbound antibodies, (Ka ～ 10¹⁰ M^?1) when applied again on identical antigen-linked affinity columns, were all retained and totally recovered after a new electrophoretic elution. Comparable results were obtained by elution with 1M NH₄OH.The residual 40% binding activity remaining on the antigen-linked Sepharose gel after electrophoretic elution was totally recovered by elution with an excess of 5α-dihydrotestosterone. It corresponded to antibodies of higher affinity (Ka ～ 10¹¹ M^?1). On the other hand the residual 40% fraction of antibodies resistant to NH₄OH elution was denaturated.     

Simultaneous analysis of substrates,products, and inhibitors of xanthine oxidase by high-pressure liquid chromatography and gas chromatography

Procedures are presented for the simultaneous analysis of hypoxanthine, xanthine, allopurinol, oxipurinol, and uric acid in standard mixtures and physiological fluids using gas chromatography (gc) or high-pressure liquid chromatography (hplc). Excellent correlation was obtained between the two methods for hypoxanthine, xanthine, oxipurinol, and uric acid. There are advantages and disadvantages to both methods. hplc requires no prior derivatization, uses isocratic elution with a buffer containing no organic solvent, and has 50- to 100-fold greater sensitivity than gc. Simpler methods of prepurification, readily adapted to clinical laboratories, can be used for hplc analysis. Although substances that are found in some urine samples from cancer patients interfere with hplc, separations by gc are not affected by these substances.     

Distribution of the Luminous Bacterium Beneckea harveyi in a Semitropical Estuarine Environment

Bioluminescent bacteria were found in the water column, sediment, shrimp, and gastrointestinal tract of marine fishes from the semitropical estuarine environment of the East Lagoon, Galveston Island, Tex. Populations in the water column decreased during cold weather while sedimentary populations persisted. The highest percentages of luminous organisms were isolated from the gastrointestinal tract of marine fishes, where they persisted during 5 days of starvation. The presence of chitin temporarily increased intestinal populations. All isolates were Beneckea harveyi, whose natural habitat appears to be the gut of fishes and whose free-living reservoir appears to be marine sediments.     

Late ventricular fibrillation following successful resuscitation from postinfarction cardiogenic shock with intraaortic balloon pumping

Early ventricular fibrillation occurs in approximately 5% of patients admitted for acute myocardial infarction. Although late ventricular fibrillation (> 48 hours postinfarction) may occur in stable patients, it occurs more commonly when severe left ventricular power failure is present. We have encountered late ventricular fibrillation in three of 42 (7%) patients treated with intraaortic balloon pumping (IABP) for profound cardiogenic shock secondary to myocardial infarction. These patients progressed to our hemodynamic Class A prior to weaning, and were thought to be stable prior to IABP removal. They were the only ones who expired after achieving Class A status. The episodes of late ventricular fibrillation occurred after the patients had been successfully weaned from IABP and were free of arrhythmias. This experience suggests that prolonged antiarrhythmic therapy may be indicated for postinfarction patients who have had ventricular dysrhythmias during IABP support.     

Effects of plant diversity and time of colonization on an herbivore-plant interaction

Summary Experimental field plantings showed that plant diversity strongly affected the population dynamics of a specialist herbivore, the striped cucumber beetle, Acalymma vittata (Fab.) (Coleoptera: Chrysomelidae). Population densities over time were characterized by two peaks in numbers (from colonization and reproduction, respectively) and were consistently higher in cucumber monocultures (Cucumis sativus L.) than in polycultures of cucumbers, corn (Zea mays L.), and broccoli (Brassica oleracea L.). Greater abundances in monocultures appear to result from two factors: (1) per individual reproductive rates were greater in monocultures than in polycultures, and (2) mark-recapture studies confirmed that beetles stay in monocultures for a longer period of time than in polycultures. Differences in predation did not appear to contribute to the overall differences in herbivore abundances.The primary impact of A. vittata on its host plant, C. sativus, is the dissemination of bacterial wilt disease, Erwinia tracheiphila (E.F.Sm.). Greater numbers of beetles led to greater plant mortality in monocultures. It is suggested that factors other than numbers of beetles (e.g., shading, allelopathy, microclimate) are more important in influencing plant reproduction, since cucumber plants in monocultures had greater yields than did plants grown in polycultures. However, time of beetle colonization strongly affected plant parameters, indicating that the length of time during which herbivores are interacting with plants is of critical importance to plant survivorship, and thus reproduction.     

The genetic structure of the kuwaiti population II: The distribution of Q-band chromosomal heteromorphisms

Summary The distribution of Q-band heteromorphisms in three Kuwaiti communities is reported. Of particular significance is the finding of large-Y segregating at a very high frequency (61.9%) in the Ajman tribesmen; and the absence of small-Y in the two tribal communities. The large variation in size of the Y-chromosome may reflect a unique cytogenetic feature of the inhabitants of the Arabian peninsula.     

Localisation régionale des gènes humains IDHS,MDHS, PGK, α-GAL,G6PD par l'hybridation cellulaire interspécifique

Summary 22 independent man-hamster (HGPRT^–) hybrids using male human cells with balanced reciprocal translocation t(X;2)(p22;q32) were analysed for human genes localized on chromosome 2 (IDH_S, MDH_S), on chromosome X (PGK, GAL, G6PD) and for the different chromosomes in relation with the balanced reciprocal translocation (chr.2, chr.2q^–, chr.Xp⁺).The following results were obtained:The chromosomes 2 and 2q^– are absent in the 22 hybrids.In 9 hybrids, the absence of MDH_S in spite of the presence of the chromosome Xp⁺ indicates that the gene for MDH_S is not localized on this chromosome (or that the gene for MDH_S is not on the segment 2q32-2qter translocated on X).In 14 hybrids, the three markers of X (PGK, GAL, G6PD) and IDH_S are expressed in the presence of the chromosome Xp⁺. This result indicates that the genes for these markers are on Xp⁺ or that the genes PGK, GAL, G6PD are on X without the Xp22-Xter segment, translocated on the chr.2, and that the gene for IDH_S is on the 2q32-2qter segment translocated on X.In 8 hybrids, in the absence of the intact chromosome Xp⁺, the higher percentage of the presence of G6PD (7 hybrids) and the lower percentage of the presence of IDH_S (3 hybrids) are explained by the fact that these hybrids selected in HAT medium had to retain a segment of Xp⁺ bearing the human gene HGPRT. G6PD appeared very close to HGPRT and IDH_S very distant from HGPRT.The study of the different correlations between the presence and the absence of these four markers on Xp⁺ in the different hybrids indicates the following order on the chromosome Xp⁺ from p to q: IDH_s — PGK — GAL — G6PD.

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Groupe INSERM: Directeur J. Frézal

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Groupe CNRS, ER, 149: Directeur J. de Grouchy     

Partial 9q trisomy associated with a 9,21 translocation

Summary A new case of partial trisomy 9q was found in a child presenting two de novo aberrations: a deletion of the long arms of 9 and a 9,21 translocation. A tentative cytogenetic explanation is put forward.