Modification of cell evagination and cell differentiation in quail oviduct hyperstimulated by progesterone

Quail oviduct development is controlled by sex steroid hormones. Estrogen (E) induce cell proliferation, formation of tubular glands by epithelial cell evagination and cell differentiation. Progesterone (P) strongly increases the secretory process in E-treated quails, but inhibits cell proliferation, cell evagination and differentiation of ciliated cells. The balance between E and P is critical for harmonious development of the oviduct. After 6 daily injections of two doses of estradiol benzoate (10 or 20 micrograms/d) and high doses of P (4 mg/d), tubular gland formation by epithelial cell evagination was inhibited, while epithelial cell proliferation occurred, as shown by the height of the villi and the increase in DNA. Secretory processes were strongly stimulated. Ovalbumin, a tubular gland cell marker and avidin, a mucous cell marker, were localized by immunofluorescence and immunogold labeling. Ovalbumin was localized only in the rudimentary tubular glands, whereas avidin was dispersed throughout the secretory cells. High doses of progesterone inhibited tubular gland cell proliferation, disturbed the distribution of avidin and inhibited differentiation of ciliated cells. Ovalbumin synthesis occurred only in epithelial cells which were evaginated despite the hyperstimulation. Ovalbumin gene expression appeared highly dependent upon the cell position.     

On the solution of mathematical models of herd immunity in human helminth infections

The general solution of the mathematical model of herd immunity to human helminth infections recently proposed by Anderson and May [3] is obtained. The numerical solution of a more accurate biological model is indistinguishable from the corresponding exact solution of a more tractable mathematical model. Computer simulations of some particular cases of this model support the notion that both ecological and immunological factors determine the observed convex patterns of age-prevalence and age-intensity curves of human helminth infections.This work was made thanks to the advise and support of Dr. Robert M. May while the author was Postdoctoral Fellow at Princeton University     

Identification of a novel 7-cis-11-trans-lipoxin A4 generated by human neutrophils: total synthesis, spasmogenic activities and comparison with other geometric isomers of lipoxins A4 and B4

Addition of (15S)-hydroxy-5,8,11-cis-13-trans-eicosatetraenoic acid (15-HETE) and the ionophore A23187 (2.5 microM) to human neutrophils led to the formation of both lipoxin A4 and lipoxin B4 as well as a novel 5,6,15-trihydroxyeicosatetraenoic acid. The new compound was identified using an improved isolation and detection system and its basic structure was determined by physical methods. On the basis of biosynthetic considerations, geometric isomers of lipoxin A4 and lipoxin B4 were prepared by total synthesis. Comparison of these synthetic materials with the neutrophil-derived product showed that the new compound is (5S,6R,15S)-trihydroxy-9,11,13-trans-7-cis-eicosatetraenoic acid or the 7-cis-11-trans-isomer of LXA4 (7-cis-11-trans-LXA4). LXA4, 11-trans-LXA4, 7-cis-LXA4 and 7-cis-11-trans-LXA4 all evoked dose-dependent (0.1-10 microM) contractions of the guinea pig lung strip, whereas 6-cis-LXB4 and 6-cis-8-trans-LXB4 relaxed this preparation. LXA4 and 7-cis-LXA4 were approx. 10-times more potent than the compounds with 11-trans geometry. However, all four double-bond isomers of LXA4 caused contractions which, based upon pharmacological evidence, appeared to involve specific activation of the same site as cysteinyl-containing leukotrienes. In conclusion, 7-cis-11-trans-LXA4 was isolated and identified as a novel biologically active eicosanoid formed by human neutrophils.     

Detection of prophospholipase A2 in human spermatozoa

Prophospholipase A2 (proPA2) has been isolated from human spermatozoa after acid extraction and chromatography on hydrophobic WP-Butyl (C4) and ion-exchange (SP 5PW) columns. The addition of benzamidine, a noncompetitive synthetic trypsin inhibitor, to semen samples has kept a portion of the sperm phospholipase A2 (PA2) in its zymogen form and allowed its isolation after acid extraction. When radioactive phosphatidylcholine (PC) or phosphatidylethanolamine (PE) were used as substrates, an identical elution profile of this enzyme was obtained on a C4 column. The proenzyme was separated from active PA2 on the C4 column. Human sperm proPA2 exhibited a less cationic charge than active PA2 on the SP 5PW column. Porcine pancreatic proPA2 had the same chromatographic behavior on high performance liquid chromatography (HPLC) (SP 5PW) as human sperm proPA2. The purification procedure resulted in the isolation of proPA2 which, upon activation by proteolysis, presented the same chromatographic elution profile on HPLC as active PA2 of human spermatozoa and porcine pancreas. Thus, a zymogen form of PA2 exists in human spermatozoa.     

Copy number and distribution of P and I mobile elements in Drosophila melanogaster populations

The distribution of the number of copies of P and I transposable elements per genome was investigated by in situ hybridization for a large set of Drosophila melanogaster strains. These included the P, Q and M types of the P-M system of hybrid dysgenesis. P element copy number varied widely (range 5–59). P and Q strains had around 40 copies whereas M strains generally had lower numbers (between 5 and 35) with one extreme value (52). The copy number of I elements appeared to be precisely regulated, as no strains were found outside the 15±5 range. The number of copies of the two families were independent. An excess of P copies on the X chromosome compared with the autosomes was found for the P and Q strains, but not for M strains. Among X-inserted P sites, a very high frequency of occupation was found at the tip of the X chromosome (cytological site 1A), especially for P and Q strains. The possible regulatory role in the P-M system of X-inserted P sites is discussed.     

Immunodetectable galactosyltransferase is associated only with human spermatozoa of high buoyant density

Human ejaculated spermatozoa are heterogeneous and can be separated into two distinct populations according to their respective buoyant densities. In order to investigate the functional differences between these two types of spermatozoa, we have searched for the presence of galactosyltransferase. A Western blot of sperm proteins following their electrophoresis was probed with an anti-galactosyltransferase serum revealing that this enzyme is present in human spermatozoa. Furthermore, galactosyltransferase is detectable only in those proteins isolated from the head of high density spermatozoa. These results suggest that ejaculated spermatozoa consist of two populations that are functionally different.     

Evidence for a novel growth factor in Xenopus oocytes

Xenopus oocytes contain a novel growth factor, as determined by its effect on the anchorage-dependent and -independent growth of various rat cells and on a Xenopus cell line; it is destroyed by trypsin, acidification (pH 2.0), heating (100 degrees C, 3 min), 8 M urea but not by dithiothreitol. Gel filtration of this activity in nondissociating conditions suggests the existence of aggregates and the presence of a very high (approximately 2000 Kd) and a much lower (approximately 30 Kd) form.     

Cystic fibrosis typing with DNA probes and screening for ΔF508 deletion in families from Southern France

Summary A sample of 235 individuals from 49 French cystic fibrosis (CF) families with at least one living affected child was typed with probes for restriction fragment length polymorphisms (RFLPs) known to be linked to the CF gene, and was screened for the ΔF508 mutation. Using a combination of six probes, 44 out of the 49 families were sufficiently informative to enable prenatal diagnosis or carrier determination. As in many other populations, linkage disequilibrium was found between the CF locus and the haplotype B (XV2c: allele 1; KM19: allele 2), which accounts for about 78% of CF chromosomes in our families. The ΔF508 deletion was present in 64.3% of CF chromosomes.     

Distal trisomy 14q

Summary Two cases of chromosome 14 rearrangements with partial duplication which occurred de novo were analyzed by Southern blot analysis using IGH, D14S1 and PI probes. In the first case, with a 46,XX,14p+ karyotype, our study confirms that the additional material on chromosome 14p+ results from a duplication of the 14q region containing the IGH, D14S1 and PI loci. In the second case, our study reveals only one 14q32 locus per chromosome 14 indicating that the extra material does not contain the 14q32 region. Our results demonstrate that molecular probes of the 14q32 region are valuable tools for the characterisation of chromosome 14 abnormalities appearing de novo.     

Functional morphology of the bronchovascular barrier of the human lungs during various age periods

Cellular components of the bronchovascular barrier have been studied in human lungs obtained after death of some patients with acute and chronic lung inflammatory diseases, hypertonic disease, atherosclerosis and chronic glomerulonephritis. Certain oxidative-reductive and hydrolytic enzymes, including NAD-, NADP- diaphorases, lactic dehydrogenase, acid and alkaline monophosphoesterase, ATP-ase, adenylate cyclase and nonspecific esterase were evaluated quantitatively after the histochemical processing of the specimens for the above reactions. Correlation analysis was performed for the bronchial epithelium, endotheliocytes, lymphocytes, plasma and mast cells, as well as macrophages and polymorphonuclear leucocytes. The results showed that there was a significant shift in some of the measured enzymic activities. Moreover, the correlations between different quantitative data were noted and these correlations changed with age. The increase in "rigidity" of the correlations in the elements of the bronchovascular barrier has been demonstrated during the process of ageing.