Unique features of brain metastases-targeted AGuIX nanoparticles vs their constituents: A focus on glutamate-/GABA-ergic neurotransmission in cortex nerve terminals.

Gadolinium-based radiosensitizing AGuIX nanoparticles (AGuIX) currently tested two phase 2 clinical trials in association with radiotherapy for the treatment of brain metastases. Here, excitatory/inhibitory neurotransmission was assessed in rat cortex nerve terminals in the presence of AGuIX and their constituents (DOTAGA and DOTAGA/Gd) at concentrations used for medical treatment, and those 5-24 times higher. The ambient level, transporter-mediated, tonic and exocytotic release of L-[C]glutamate and [H]GABA, the membrane potential of nerve terminals were not changed in the presence of AGuIX at concentrations used for medical treatment ([Gd] = 0.

Pan-African phylogeny of Mus (subgenus Nannomys) reveals one of the most successful mammal radiations in Africa.

Background: Rodents of the genus Mus represent one of the most valuable biological models for biomedical and evolutionary research. Out of the four currently recognized subgenera, Nannomys (African pygmy mice, including the smallest rodents in the world) comprises the only original African lineage. Species of this subgenus became important models for the study of sex determination in mammals and they are also hosts of potentially dangerous pathogens.

Structure of tBuCO-Val psi [NH-CO]NHtBu.

N-Isobutylidenedipivalamide, C14H28N2O2, Mr = 256.39, orthorhombic, P2(1)2(1)2(1), a = 16.656 (2), b = 9.

Structural organization of the Corynebacterium glutamicum plasmid pCG100.

pCG100, a 3 kb cryptic plasmid of Corynebacterium glutamicum ATCC 13058, probably identical with pSR1 from C. glutamicum ATCC 19223, was characterized. The minimum region for autonomous replication was shown to be contained on a 1.

Study in vitro of the phagocytic function of Sertoli cells in the rat.

Aspects of the interaction between residual bodies/cytoplasts from elongated spermatids (RB/CES) and Sertoli cells were studied in vitro. Highly enriched Sertoli cells (91%: experiment A), very highly enriched Sertoli cells (greater than 96%: experiment B), as well as peritubular cells were isolated from testes of 20-day-old rats by means of hypotonic treatment. Isolated Sertoli cells and peritubular cells were also prepared from 45-day-old rats (experiment C).

Regulation of Sertoli cell inhibin production and of inhibin alpha-subunit mRNA levels by specific germ cell types.

To elucidate the endocrine and paracrine regulation of testicular inhibin production, the effects of follicle-stimulating hormone (FSH), (Bu)2cAMP, germ cells (either crude or enriched preparations) and germ cell-conditioned media on inhibin production (immuno- and bio-activities) and the levels of alpha- and beta B-subunit mRNAs were assessed in cultured Sertoli cells isolated from 20-day-old rats. FSH and (Bu)2-cAMP stimulated both secreted and intracellular inhibin levels in a dose-dependent manner. Using cDNA probes corresponding to the alpha-subunit and the beta B-subunit of rat inhibin it was also shown that both FSH and (Bu)2cAMP markedly increased the level of alpha-subunit mRNA but had no effect on the beta B-subunit mRNA.

A rapid and sensitive ELISA for rainbow trout maturational gonadotropin (tGtH II): validation on biological samples; in vivo and in vitro responses to GnRH.

A rapid and sensitive heterologous enzyme-linked immunosorbent assay (ELISA) was developed to measure rainbow trout maturational gonadotropin. Purified salmon maturational gonadotropin (sGtH II) was used as reference hormone. Optimization of the procedure was performed by using an anti-beta sGtH serum.

Human papillomavirus infection and filaggrin expression in paraffin-embedded biopsy specimens of extragenital Bowen's disease and genital bowenoid papulosis.

Cutaneous Bowen's disease (BD) and genital bowenoid papulosis (BP) are considered as precancerous or cancerous lesions that are sometimes infected with human papillomavirus (HPV). We studied retrospectively paraffin-embedded sections of 11 samples of cutaneous BD and 6 samples of genital BP from the general population for HPV infection and filaggrin expression. Using in situ hybridization with biotinylated probes of HPV types 1, 2, 5, 6, 11, 16, and 18, under stringent and/or non-stringent conditions and a streptavidin-alkaline-phosphatase complex for hybrid detection, HPV DNA was detected in 6/17 cases (5 BD and 1 BP).

An increase in the intracellular pH of fertilized eggs of Xenopus laevis is associated with inhibition of protein and DNA syntheses and followed by an arrest of embryonic development.

In many systems, events participating in cell division are controlled by intracellular pH (pHi). In Xenopus eggs, fertilization is accompanied by an increase in pHi which occurs concomitantly with an increase in protein synthesis and a reinitiation of DNA synthesis, leading the embryo to cell division. In this paper, we have shown that increasing pHi of fertilized eggs from 7.

Origin of the met-enkephalinergic innervation of the lateral septum in the rat.

The location of the cells giving rise to the methionine-enkephalin (Met-Enk)-ergic innervation of the lateral septal nucleus has been investigated in the rat by combining immunohistochemistry and retrograde axonal tracing. Small volumes (0.06 microliter) of apo-horseradish peroxidase (Apo-HRP) conjugated to wheat-germ agglutinin (WGA) and coupled with colloidal gold particles (WGA-ApoHRP-gold) were injected into the lateral septum.

dATP-mediated inhibition of DNA ligase by 2'-deoxycoformycin in T and B cell leukemia.

2'-Deoxycoformycin (dCF), a potent adenosine deaminase inhibitor, has been reported to display greater toxicity for T than for B lymphoblasts. Since this compound can block DNA replication and since this effect is mediated by the intracellular ATP/dATP balance, its possible effect on DNA ligase was investigated. dCF at relatively low concentrations (1 microM), in association with dATP (100 microM), is a strong inhibitor of DNA ligase in T blasts, whereas it has no significant effect in B blasts at this concentration.

Structural and biochemical observations on specialized membranes of the "filter chamber", a water-shunting complex in sap-sucking homopteran insects.

Many homopteran insects feed on plant sap which contains solutes in very low concentration. Their digestive tract presents a complex called the "filter chamber" where the excess dietary water is believed to flow directly from the initial part of the midgut to the terminal part of the midgut and the proximal regions of the Malpighian tubules. Freeze-fracture experiments carried out on the filter chamber of Cicadella viridis revealed the presence of intramembrane particles on the whole surface of the microvilli and of basal membrane infoldings of the cells.

Reproductive effects of the anticancer drug cyclophosphamide in male rats at different ages.

This study was undertaken to determine the effects of the anticancer and immunosuppressant drug cyclophosphamide (CP) on several endpoints of the male rat reproductive system at different ages; 10-day-old (experiment A), 45-day-old (experiment B), and adult (experiment C) Sprague-Dawley rats were injected intraperitoneally with CP at doses of 20 mg/kg/day or/week and 100 mg/kg/week for 2 weeks (experiment A), doses of 20 mg/kg/day for 5 weeks and 100 mg/kg/day for 10 days (experiment B), and doses of 20 mg/kg/day for 5 weeks (experiment C). In all groups CP induced a significant rate of mortality. Body weight gain was moderately to severely reduced in two groups of experiment A (20 mg/kg/day and 100 mg/kg/week) and of experiment B (20 mg and 100 mg/kg/day) but normal in the others.

Weak bases mimic the fertilization-associated chloride conductance increase and induce morphological changes in the cortex of Xenopus laevis eggs.

Ammonia and other weak bases (methylamine, trimethylamine) including certain local anesthetics (benzocaine, procaine, lidocaine) depolarized the plasma membrane of unactivated Xenopus eggs. Exposure to different [Cl-]o or to the other halides (F-, Br-, I-) revealed a similar anion dependency of the weak base-induced conductance change to that found for the normal fertilization potential. Although transient, the induced depolarization was slower and of longer duration than the fertilization potential.

Inhibition by the fungicide fenpropimorph of cholesterol biosynthesis in 3T3 fibroblasts.

Fenpropimorph (N-[3-(p-t-butylphenyl)-2-methylpropyl]-cis-2,6-dimethylmorpholine), a morpholine fungicide known to be an inhibitor of sterol biosynthesis in fungi and in higher plants, was demonstrated to be an efficient inhibitor of cholesterol biosynthesis in cultured Swiss 3T3 fibroblasts. Treatment of the mammalian cells with fenpropimorph resulted in a dose-dependent inhibition of [14C]acetate incorporation into the C27 sterols [IC50 (concentration causing half-maximal inhibition) = 0.5 microM], which was accompanied by an accumulation of polar sterols and a decrease in cellular hydroxymethylglutaryl-CoA reductase activity.

Respective influences of age and weaning on skeletal and visceral muscle protein synthesis in the lamb.

1. The influences of age and weaning on muscle protein synthesis were studied in vivo, by injecting a large dose of [3H]valine into 1-, 5- and 8-week-old suckling or 8-week-old weaned lambs. 2.

Changes in the polyadenylation of specific stable RNA during the early development of Xenopus laevis.

The distribution of four specific RNA species between the poly(A)+ and poly(A)- fractions has been studied during the first hours of Xenopus laevis development, before the mid-blastula transition (MBT). Two of these specific RNA species correspond to clones selected by differential hybridization from a Xenopus egg cDNA library. Another corresponds to Xenopus c-raf mRNA and the last one to RNA revealed by a mouse ornithine decarboxylase probe.

Selective channelling of arachidonic and linoleic acids into glycerolipids of rat hepatocytes in primary culture.

Rat hepatocytes in primary culture were incubated with a mixture of linoleic and arachidonic acid at various total fatty acid/serum albumin molar ratios. Mixed fatty acids were taken up at the same rate and distributed with the same pattern as fatty acids added separately. The rates of total uptake, incorporation into hepatocyte and secreted triacylglycerols and beta-oxidation were linearly related to the fatty acid/albumin ratios, whereas the rate of incorporation into phospholipids was saturable.

Peptides co-released with luteinizing hormone by perifused pituitary cell aggregates.

The proteins co-released with gonadotropins were analyzed using perifusion of pituitary cell aggregates from 14-day-old female rats, after a pre-labeling period with [35S]methionine. Radioimmunoassays of hormones and electrophoretic analysis were performed on each 4 min effluent. Gonadotropin-releasing hormone (GnRH) pulses increased significantly (P less than 0.

The gonadotrope polypeptide (GP 87) released from pituitary cells under luteinizing hormone-releasing hormone stimulation is a secretogranin II form.

Cultured gonadotrope cells from 14 day old female rat pituitaries have been shown to release a highly acidic protein when incubated with LHRH: the gonadotrope polypeptide (GP 87). Moreover, a new tyrosine-sulfated acidic protein, secretogranin II (Sg II), clearly distinct from the chromogranin species, was described in the secretory granule matrix of endocrine cells secreting peptide hormones by the regulated pathway. Recently, the release of Sg II from female rat pituitary stimulated by LHRH was demonstrated in vitro.

Reproductive effects of the anti-cancer drug procarbazine in male rats at different ages.

Rats aged 10 days (Exp. A), 45 days (Exp. B) and 70-90 days (Exp.

Influence of germ cells upon transferrin secretion by rat Sertoli cells in vitro.

Indirect approach (hypotonic treatment) and direct approaches (co-cultures and conditioned media) were used in order to investigate the effects of germ cells from adult rats upon transferrin secretion by Sertoli cell cultures prepared from 20-day-old rats. Removal of germ cells contaminating the Sertoli cell cultures resulted in a significant decrease in transferrin secretion whereas the addition of crude germ cell preparations or of enriched preparations of pachytene spermatocytes, early spermatids and of liver epithelial cells (LEC) markedly stimulated this parameter. Furthermore, spent media of pachytene spermatocytes and of early spermatids, but not of LEC, also stimulated transferrin production.

Association of a possible DNA ligase deficiency with T-cell acute leukemia.

DNA ligase activities were determined in blood samples of 431 different cases of lymphoblastic and nonlymphoblastic leukemia. Less activity was observed in samples from lymphoblastic patients. RNA translation together with ligase immunoprecipitation experiments show that in T-cell acute lymphoblastic leukemic cells, no ligase is translated.

The dynamics of the steroidogenic response of perifused Xenopus ovarian explants to gonadotropins.

Steroid release before and during maturation was studied in Xenopus ovarian follicles under various conditions of stimulation of LH in a perifusion system. Acute stimulation by 15 micrograms of LH induces a 10-fold increase in the androgen (testosterone and androstenedione) level which reaches a maximum 4 hr later and then slowly decreases until the 25th hour. Repeated stimulations every 2 or 4 hr are followed by the same androgen increase during the first 8 or 10 hr and then by a slow decrease in the secretion despite new LH injections.

Paracrine control of immature Sertoli cells by adult germ cells, in the rat (an in vitro study). Cell-cell interactions within the testis.

Enriched populations of germ cells prepared from adult rats were found to influence 20-day-old rat Sertoli cell secretory activity by stimulating androgen-binding protein (ABP) and inhibiting oestradiol-17 beta production in the presence of follicle-stimulating hormone (FSH) as well as of dibutyryl cyclic AMP (dbcAMP). Among the different populations tested in coculture, pachytene spermatocytes were the most effective at stimulating ABP and inhibiting oestradiol production, whereas early spermatids had relatively less effects. Cytoplasts from elongated spermatids only slightly stimulated ABP secretion.