Effects of progestins and antiprogestins on mitochondria in uterine glandular cells in the rat

Summary The administration of progesterone to ovariectomized rats induces an increase in the volume density (Vv) of the mitochondria and the appearance of giant mitochondria in the uterine glandular cells. This experimental model, including a stereological analysis, allowed us to investigate and quantify a direct effect of progesterone on a well-defined cellular structure without the intervention of estrogen in a priming phase. Synthetic compounds, promegestone, gestrinone and RU 38486, were tested in this model either in place of progesterone or simultaneously with progesterone. The potent progestomimetic activity of promegestone was confirmed by the proliferation of giant mitochondria and a high Vv value for the mitochondria, the two other compounds being inactive even at higher doses. At lower doses, gestrinone and RU 38486 partially inhibit the action of progesterone and at higher doses they both show a complete antagonist effect by preventing the development of the mitochondria.     

A method for demonstrating the heterogeneity of pigeon red cell membrane vesicles based on their glycine transport activity

A procedure is described which is capable of detecting the changes in size and/or density of small membrane vesicles resulting from solute uptake. Vesicles which have taken up solute sediment more slowly in a density gradient, the ratio of glycine uptake/vesicle-trapped space is not uniform in the vesicle population, and vesicles with higher uptake/space ratios are preferentially retarded upon centrifugation.Alanine transport activity is associated with glycine transport activity in that retardation of vesicles due to glycine uptake equally retards vesicles possessing alanine uptake activity.     

Directionality and Nonreciprocality of Chi-Stimulated Recombination in Phage λ

Chi's are genetic elements that stimulate generalized recombination in their locale in phage λ. All Chi's, wherever located on λ's chromosome, act asymmetrically in crosses blocked in DNA replication: (1) They stimulate exchange primarily to their left on the conventional λ map, and (2) the stimulated exchange is frequently nonreciprocal, the recombinant carrying the Chi element being produced less often than the complementary product.     

THE AFFINITY OF THE FUCOSE-BINDING LECTIN FROM LOTUS TETRAGONOLOBUS FOR GLYCOPEPTIDES AND OLIGOSACCHARIDES ACCUMULATING IN FUCOSIDOSIS

Abstract— The affinity of the fucose-binding lectin from Lotus tetragonolobus for fuco-oligosaccharides accumulating in the brain and other tissues of a patient with fucosidosis was studied by two methods: by inhibition of the co-precipitation of the lectin with porcine stomach mucin and by one-step affinity chromatography on a column of the lectin bound to Sepharose-4B. Both methods indicated that the lectin had greater affinity for the disaccharide Fuc(α, 1-6)GlcNAc than for either the main fucosidosis storage material in brain, a fuco-dekasaccharide, or the heterogeneous fuco-glycopeptide fractions obtained from normal human and rat brain glycoproteins. Our results suggest that the fucose residue linked α(1-6) to the N -acetylglucosamine residue involved in the N -glycosidic linkage to asparagine is not available to the lectin in the intact N -glycosidic chains of normal brain glycopeptide fractions and that the lectin has poor affinity for the Fuc(α, 1-3)Glc N Ac linkage in rat brain glycoproteins.     

Permutation of the DNA in small-headed virions of coliphage P1

Summary Use of restriction endonucleases BglII, EcoRI, BamHI, and HindIII, has established that in small-headed (PIS) virions of coliphage P1, as a population, the entire genome found in big-headed (P1B) virions is represented. In addition, the origin and direction of DNA packaging are identical in P1S and P1B virions.     

Role of gonadal hormones in development of the sexual phenotypes

Summary Male and female embryos develop in an identical fashion during the initial portion of gestation. If the indifferent gonad differentiates into an ovary (or if no gonad is present), a female phenotype is formed. Male phenotypic differentiation, however, requires the presence of an endocrinologically active testis. Two secretion of the fetal testis, Müllerian inhibiting substance and testosterone, are responsible for male development. Studies of single gene mutations that interfere with androgen action indicate that testosterone itself is responsible for virilization of the Wolffian duct system into the epididymis, vas deferens, and seminal vesicle, whereas the testosterone metabolite dihydrotestosterone induces development of the prostate and male external genitalia. Thus, impairment of dihydrotestosterone formation results in a characteristic phenotype consisting of predominantly female external genitalia but normally virilized Wolffian ducts. The molecular mechanisms by which testosterone and dihydrotestosterone act during fetal development appear to involve the same high affinity receptor, a protein that transports both testosterone and dihydrotestosterone to the nucleus of target cells. When this receptor is either absent, deficient, or structurally abnormal, the actions of both testosterone and dihydrotestosterone are impaired, and the resulting developmental anomalies involve both internal and external genital structures.The original work described in this review was supported by grant AM 03892 from the National Institutes of Health     

Fine structure of ocelli in larvae of an archiannelid,Polygordius cf. appendiculatus

Summary The ocelli of trochophore and segmented larvae of the archiannelid Polygordius cf. appendiculatus were studied by electron microscopy. An eye consists of two pigmented supportive cells forming an eyecup that encloses one sensory cell bearing one (trochophore) or two (segmented larva) ranks of microvilli and one adventitious cilium. Remarkably abundant tubules (submicrovillar endoplasmic reticulum) radiate from the perinuclear region of the sensory cell, which lies outside the ocellus, toward its receptoral end. Possible functions of the tubules are proposed: carriers of ions, metabolites and photopigments; pinocytic uptake of products resulting from photoreception; storage of membrane; and light guides. Finally, the eyes of Polygordius larvae are believed to have evolutionary significance and provide further support for Eakin's theory of diphyletic origin of photoreceptors.     

Bactericidal activity of tuftsin

Summary The biological activities of the phagocytosis stimulating tetrapeptide, Thr-Lys-Pro-Arg are discussed. A brief account on the stimulation by tuftsin of phagocytosis of various particles, including bacteria was reported. Stimulation of bactericidal activity by this tetrapeptide was investigated in vitro as well as in vivo. The potency of tuftsin to enhance blood clearing of Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Serratia marcescens by mouse peritoneal macrophages was demonstrated.Bactericidal activity and effects of tuftsin on this phenomenon were studied in liver and spleen of mice. Tuftsin stimulates these activities. Same experiments were performed in infected leukemic mice by Serratia marcescens or Escherichia coli. Results on blood clearing and bactericidal activities in liver and spleen were reported and compared to those of healthy and leukemic untreated animals. Tuftsin was found to present interesting stimulatory effects on the bactericidal activity of phagocytes.