Attribution des signaux de résonance magnétique nucléaire-13c de disaccharides peracétylés dans la série du D-glucose

Selective, double irradiation allows the assignment of most ¹³C-n.m.r. signals in a series of per-O-acetyl disaccharides composed of two D-glucose residues linked α-(1→3), β-(1→3), α-(1→4), β-(1→4), α-(1→6), β-(1→6), and α,α-(1→1). The main influences that affect the chemical shifts are discussed and the spectra of β-cellobiose octaacetate and β-maltose octaacetate are compared to those of cellulose and amylose triacetate, respectively, to show the possibilities and limitations of a disaccharide model for the interpretation of the ¹³C-spectrum of a polymer.     

Radioimmunoassay of prostaglandins E1, E2, and F2α in unextracted plasma, serum and myocardium

A radioimmunoassay procedure for the determination of PGE₁, PGE₂, and PGF₂α is presented. The procedure involves the pre-precipitation of each prostaglandin specific antiserum with the precipitating antisera (ARGG), and the use of these antisera mixtures in assaying for PGE₁, PGE₂, and PGF₂α. Applicability of the methods to unextracted plasma, serum and myocardial homogenate has been demonstrated through tests of specificity, recovery, reproducability and parallelism. A mathematical correction for cross-reactivity between PGE₁ and PGE₂, and their opposing antisera is given. To demonstrate the utility of the methodology in differentiation of experimental variables, prostaglandin concentrations in unincubated serum, incubated serum, and the rate of prostaglandin production in serum of dogs are given.     

Leukocyte migration inhibitory factor (LMIF) production in unidirectional mixed lymphocyte cultures.

Puromycin treatment of lymphocytes was used to develop a one-way test for leukocyte migration inhibitory factor (LMIF) production in the mixed lymphocyte culture (MLC) reaction. Lymphocytes incubated with this protein synthesis inhibitor induced a vigorous mediator production by nontreated allogeneic cells, being themselves unable to respond to stimulator cells. When puromycin-treated cells were stimulated with the mitogens PHA, ConA, or PWM, overall protein and DNA synthesis were significantly decreased with concomitant abolishment of LMIF production. Viability of stimulator lymphocytes was found to be essential for generation of the mediator in MLC reaction.     

Circadian variations of the effects of ethanol and of blood ethanol values in the healthy adult man. Chronopharmacological study]

Six healthy young men (22 to 26 years) who had fasted for 12 hours volunteered for this study (subject synchronization: diurnal activity from 07(00) to midnight and nocturnal rest). A set dose of ethanol (0.67 g/kg body weight) was ingested at the fixed (and random) hours of 07(00), 11(00), 19(00) and 23(00), with a week between tests. A set of physiological variables: psychological tests (selft-rating of mood, of physical vigor and of ebriety, tempo, random number addition test); physical variables (heart rate, systolic and diastolic blood pressure, peak expiratory flow, oral temperature and grip strength); blood variables (plasma ethanol, cortisol, lactic acid, pyruvic acid, glucose and erythrocyte K+) and urinary variables (volume, epinephrine, nor-epinephrine and 5-HIAA) were documented at least at 4 hourly intervals and set times. The cosinor method was used for chronobiological statistical analyses. The parameters characterizing the ethanol pharmacokinetics (chronopharmacokinetics) demonstrated a circadian rhythm (p less than 0.05): e. g. the peak height of ethanolemia is greater when ethanol is ingested at 07(00) than at other times. Also a circadian rhythm in biosystems susceptibility can be demonstrated (p less than 0.05) (chronesthesy) with a peak time not necessarily corresponding either to that of ethanolemia or to that of other variables. The overall circadian changes in ethanol effects (chronergy) can be viewed as a combination of both ethanol chronesthesy and chronokinetics.     

Impact of Anesthetics on Immune Functions in a Rat Model of Vagus Nerve Stimulation

Vagus nerve stimulation (VNS) has been successfully performed in animals for the treatment of different experimental models of inflammation. The anti-inflammatory effect of VNS involves the release of acetylcholine by vagus nerve efferent fibers inhibiting pro-inflammatory cytokines (e.g. TNF-α) produced by macrophages. Moreover, it has recently been demonstrated that splenic lymphocytic populations may also be involved. As anesthetics can modulate the inflammatory response, the current study evaluated the effect of two different anesthetics, isoflurane and pentobarbital, on splenic cellular and molecular parameters in a VNS rat model. Spleens were collected for the characterization of lymphocytes sub-populations by flow cytometry and quantification of cytokines secretion after in vitro activation. Different results were observed depending on the anesthetic used. The use of isoflurane displayed a non-specific effect of VNS characterized by a decrease of most splenic lymphocytes sub-populations studied, and also led to a significantly lower TNF-α secretion by splenocytes. However, the use of pentobarbital brought to light immune modifications in non-stimulated animals that were not observed with isoflurane, and also revealed a specific effect of VNS, notably at the level of T lymphocytes’ activation. These differences between the two anesthetics could be related to the anti-inflammatory properties of isoflurane. In conclusion, pentobarbital is more adapted than isoflurane in the study of the anti-inflammatory effect of VNS on an anesthetized rat model in that it allows more accurate monitoring of subtle immunomodulatory processes.     

Sex in Penicillium: Combined phylogenetic and experimental approaches

We studied the mode of reproduction and its evolution in the fungal subgenus Penicillium Biverticillium using phylogenetic and experimental approaches. We sequenced mating type (MAT) genes and nuclear DNA fragments in sexual and putatively asexual species. Examination of the concordance between individual trees supported the recognition of the morphological species. MAT genes were detected in two putatively asexual species and were found to evolve mostly under purifying selection, although high substitution rates were detected at some sites in some clades. The first steps of sexual reproduction could be induced under controlled conditions in one of the two species, although no mature cleistothecia were produced. Altogether, these findings suggest that the asexual Penicillium species may have lost sex only very recently and/or that the MAT genes are involved in other functions. An ancestral state reconstruction analysis indicated several events of putative sex loss in the genus. Alternatively, it is possible that the supposedly asexual Penicillium species may have retained a cryptic sexual stage.     

Expression of chemerin and its receptors in the ovaries of prepubertal and mature gilts

Recent studies have demonstrated that chemerin participates in the regulation of female reproductive function at the level of the ovaries. Due to the lack of data concerning the presence of the chemerin system (chemerin and its receptors: CMKLR1, GPR1, CCRL2) in the ovaries of pigs, one of the most economically important livestock species, the aim of this study was to investigate the expression and localization of chemerin and its receptors in the ovaries of prepubertal and mature gilts. We also aimed to examine the concentrations of chemerin in the follicular fluid of prepubertal and mature animals. In the present study, we have demonstrated the expression patterns of chemerin system components in the porcine follicles of different sizes of prepubertal and mature animals, as well as in corpora lutea of mature gilts during the estrous cycle and early pregnancy. The obtained results suggest that the expression of chemerin system components is influenced by the reproductive stage, cell type, and the hormonal status of gilts (the estrous cycle/pregnancy). We have also presented the localization of the chemerin system components in various ovarian structures, and also showed changes in the concentration of chemerin in the follicular fluid of pigs. The presented findings not only confirm that chemerin is produced locally in the porcine ovary but they also demonstrate that chemerin directly affects ovarian cells, as confirmed by the presence of chemerin receptors in all ovarian structures. Therefore, chemerin appears to be an important intra‐ovarian factor that could regulate ovary function in pigs.