Analysis of the DNA replication pattern of a translocation (tX/X,qter→p221::p223→qter) chromosome in leukocyte and fibroblast cultures

Summary The results of a detailed analysis of DNA replication in a late replicating tX/X chromosome (qter p221::p223 » qter) are reported. The chronology of DNA replication has been analyzed by comparing (a) the replication patterns of each of the two moieties of the translocation chromosome in different cells and (b) the two moieties with each other in the same cell. The study has been done on leukocyte and fibroblast cultures after BUdR incorporation. A comparison with the late replication pattern of the normal X chromosome has also been done.     

Effect of the Compound CGA 78039 and Streptomycin on the Expression of Bacterial Stem Rot in Dieffenbachia

Bacterial stem rot, due to Erwinia chrysanthemi , is a serious problem in ornamental crop protection, e.g. in Dieffenbachia . It was our aim to compare the effect of the synthetic compound CGA 78039 and streptomycin sulphate on the suppression of stem rot disease in Dieffenbachia . Different treatments were applied under natural and artificial infection pressures. Pretreatment of the mother plants with CGA 78039, followed by dipping of the cuttings overnight in the same solution before potting and five subsequent weekly foliar sprays during growth reduced the expression of stem rot in Dieffenbachia significantly.     

Induction of ovulation with pulsatile luteinising hormone releasing hormone.

Ovulation was successfully induced with luteinising hormone releasing hormone in 28 women with hypothalamic amenorrhoea who had failed to respond to treatment with clomiphene. Luteinising hormone releasing hormone was administered in a pulsatile manner with miniaturised automatic infusion systems. The rate of ovarian follicular maturation, as monitored by serial pelvic ultrasonography, was similar to that observed in spontaneous cycles. Endocrine assessment by serial measurement of gonadotrophin, oestradiol, and progesterone concentrations showed hormone concentrations to be within the normal range. Intravenous treatment was required in only two patients, the remainder responding satisfactorily to subcutaneous infusion. All patients conceived within six cycles of treatment, and only one multiple pregnancy occurred.     

The fate of bilirubin-IXalpha glucuronide in cholestasis and during storage in vitro. Intramolecular rearrangement to positional isomers of glucuronic acid.

1. In aqueous solution above pH7 bilirubin-IXalpha 1-O-acylglucuronide rapidly isomerizes to the non-C-1 glucuronides by sequential migration of the bilirubin acyl group from position 1 to positions 2, 3 and 4 of the sugar moiety. The transformations are enhanced by increasing the pH. Compared with the rates at 37 degrees C the transformations are rather slow at 0 degrees C. Virtually complete inhibition is observed at values below pH6. The isomerization at 25 degrees C and pH 7.4 is not affected by the presence in the solutions of a molar excess of human serum albumin. 2. Isomerization in bile kept at 37 degrees C at pH7.7-7.8 is probably non-enzymic, as the rates of change are similar to those observed under comparable conditions for aqueous solutions of glucuronides of bilirubin-1Xalpha and of azodipyrrole. 3. Analysis without delay of normal biles of man and rats collected at 0 degrees C over a maximum period of 10 min shows that the bilirubin-IXalpha mono- and di-glucuronides consist exclusively of the 1-O-acyl isomers. 4. The mixtures of the four positional isomers of bilirubin-IXalpha glucuronide found in freshly collected biles of man and rats with cholestasis probably originate from initially synthesized 1-O-acylglucuronide by the same mechanism of sequential migration as has been observed in aqueous solutions of conjugated bilirubin-IXalpha.     

Étude d'un extrait de Sporothrix schenckii (forme levure). Analyse électrophorétique et immunoélectrophorétique; caracterisation des activités enzymatiques

Résumé Un extrait de S. schenckii a été préparé à partir de levures vivantes provenant d'une culture agitée pendant 3 jours à 35° C et à l'obscurité dans du milieu BHI (brain heart infusion). Il a été obtenu par broyage au broyeur cellulaire MSK et amélioré par une congélation-décongélation. Ses constituants, séparés par électrophorèse, ont été révélés par leur activité enzymatique; 30 bandes ont ainsi pu être caractérisées. Ces activités enzymatiques ont été recherchées au niveau des fractions de l'extrait révélées par un hyperimmunsérum de lapin: 16 sur les 22 précipités sont identifiés par leur pouvoir catalytique. L'ordre d'apparition des premiers anticorps chez le lapin immunisé et leur identification complètent cette étude. Les conditions de culture et de préparation permettant d'améliorer la qualité de l'extrait sont également précisées.

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An extract from living yeast forms of S. schenckii was prepared. The yeasts originated from a shake culture in B.H.I. broth (Difco) incubated for 3 days at 35°C in darkness; they were harvested, washed and disrupted with glass beads in a model MSK Braun mechanical cell homogenizer; a freezing-thawing was added to improve the extract.After electrophoretic separation in agarose gel, the extract's components were characterized by their enzymic activity; with this technique, 30 bands were revealed. These enzymic activities were also investigated on the antigenic fractions of the extract revealed by a rabbit hyperimmunserum: 16 among 22 immunoprecipitates are identified by their catalytic properties. Study of the earliest precipitating antibodies (appearing-order and enzymic caracterization) in rabbits just immunized completes this work. How to ameliorate the quality of the extract by culture and extraction conditions is also specified.

     

Oxygen metabolism by the anaerobic bacteriumVeillonella alcalescens

Veillonella alcalescens contained a membrane-bound lactate oxidase system. Studies on the effect of inhibitors on lactate oxidase showed the participation of non-heme iron, quinone and cytochromesb andd. Superoxide anion radicals ( ) and H₂O₂ were shown to be formed at lactate oxidation and presumably arose from cyanide- and azide-resistant side chains of the respiratory system. The H⁺/O ratio withL-lactate as a hydrogen donor was 2.3. When an anaerobic culture growing on lactate was shifted to a high dissolved oxygen tension (d.o.t.=15 kPa) rapid inhibition of growth and lactate conversion occurred. This could be correlated with a rapid inactivation of lactate dehydrogenase. The effects of high d.o.t.'s on lactate dehydrogenase, lactate conversion and growth were reversible. After a shift to low d.o.t.'s (<2.5 kPa) growth ofV. alcalescens continued for one or two doublings whereafter lysis did occur. Acetate and pyruvate were the main fermentation products. P/O ratio's were calculated from molar growth yields and fermentation balances. A P/O value of 0.66 was found after a shift to a very low oxygen supply at which the d.o.t. presumably was zero. Shifts to higher d. o. t.'s gave much lower growth yields. Presumably, under these conditions uncoupling between growth and energy production occurred. Accumulation of toxic oxygen compounds was given as an explanation for the behaviour ofV. alcalescens at low d.o.t.'s.Abbreviations HQNO 2-n-heptyl-4-hydroxy-quinoline-N-oxide - CCCP carbonyl cyanide m-chlorophenyl-hydrazone - ABTS 2,2-azino-di-3-ethyl-benzthiazoline sulfonate - DCPIP 2,6 dichlorophenolindophenol - PMS phenazine methosulfate - NBT p-nitro blue tetrazolium chloride - d.o.t. dissolved oxygen tension - SOD superoxide dismutase     

Thermal denaturation of nucleosomal core particles.

Thermal denaturation of very homogeneous preparations of core particles from chicken erythrocyte chromatin is studied by several techniques. The change in absorbance, which is very closely paralleled by changes in heat capacity, which is very closely paralleled by changes in heat capacity, is a biphasic process with inflexions at 60 degrees C and 74 degrees C. In contrast, isolated DNA of the same length denatures in a single transition around 44 degrees C. Monitoring the circular dichroism of the cores during thermal denaturation reveals biphasic changes in the secondary structure of the DNA, preceding the base unstacking by 10 degrees C in the first and 3 degrees C in the second phase. However, measurable alterations in the secondary structure of the histones are confined to the second phase with a melting temperature at 71 degrees C. Increase in the ionic strength of the buffer from 1 mM to 10 mM leads to almost monophasic melting curves as measured by absorbance and CD, while not causing any measurable conformational changes at room temperature. The melting of core particles is interpreted as a denaturation of about 40 base pairs in the first phase, followed by a massive breakdown of the native structure of a tight histone-DNA complex, which frees the remaining 100 base pairs for unstacking.     

Comparative studies in two cases of testicular feminization syndrome,one with and the other without the fluorescent distal band q12 of the Y

Summary In two patients with testicular feminization syndrome, one Yq12-positive and the other Yq12-negative, we compared phenotype, gonadal histology and ultrastructure, in vivo steroid response of the testes to the administration of exogenous gonadotropin during adrenal suppression, and of the adrenal gland to ACTH. The assumption that the constitutive Y heterochromatin could function as a regulator of steroid biosynthesis and metabolism, with or without effect at other levels, was not firmly supported by the observations reported here. However, further studies along this line may help elucidate the biologic role of this portion of the Y chromosome in humans.