Decreased lactose percentage in milk associated with quarter health disorder and hyperketolactia, a proxy for negative energy balance, in dairy cows.

Several studies have described variations in lactose content (LC) in dairy cows during udder quarter health disorder or negative energy balance (NEB). However, their joint effects on LC have never been described. This was the aim of a longitudinal observational study performed on 5 Quebec dairy farms using automatic milking systems. Quarter milk samples were collected every 14 d from 5 to 300 DIM. Quarter health status was described by combining SCC level (SCC- or SCC+: < or ≥100,000 cells/mL, respectively) and infectious status (Patho- or Patho+: absence or presence of pathogens on a milk culture, respectively). Cows with NEB in early lactation (DIM <70) were identified using milk BHB content: <0.15 mM = BHB-; 0.15 to 0.19 mM = BHB+; >0.19 mM = BHB++. A total of 14,505 quarter cisternal milk samples were collected from 380 lactating cows. The quarter LC was analyzed using a mixed linear regression model with the following fixed effects: quarter health status, parity, time interval between last milking and sampling, quarter milk yield (in kg/d), DIM, and herd. A random quarter intercept with a repeated measures correlation structure and a cow random intercept were also specified. The LC of SCC+ quarters was lower (-0.17 ± 0.013 percentage points) compared with LC of SCC- quarters for both primiparous and multiparous cows. Of the 162 bacterial species identified, only 8 species had a prevalence greater than 4.0%, and just 5 of them were associated with a reduction in LC: Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, Staphylococcus epidermidis, and Staphylococcus simulans. Cows identified as BHB+ and BHB++ in early lactation had a lower LC (-0.05 ± 0.019 and -0.13 ± 0.020 percentage points, respectively) compared with BHB- cows. For BHB++ cows, in both parity groups the decrease in LC (-0.20 ± 0.025 percentage points) was higher in SCC+ quarters compared with SCC- quarters. Moreover, the additive effect of the quarter health status and NEB on milk LC was greater with larger increases in BHB. Our findings highlight the necessity to jointly take into consideration both quarter health status and milk BHB concentration when using LC as a biomarker for NEB.

Towards an improved access to psychiatric rehabilitation: availability and effectiveness at 1-year follow-up of psychoeducation, cognitive remediation therapy, cognitive behaviour therapy and social skills training in the FondaMental Advanced Centers of Expertise-Schizophrenia (FACE-SZ) national cohort.

Psychosocial Interventions (PIs) have shown positive effects on clinical and functional outcomes of schizophrenia (SZ) in randomized controlled trials. However their effectiveness and accessibility remain unclear to date in "real world" schizophrenia. The objectives of the present study were (i) to assess the proportion of SZ outpatients who benefited from PIs between 2010 and 2015 in France after an Expert Center Intervention in a national multicentric non-selected community-dwelling sample; (ii) to assess PIs' effectiveness at 1-year follow-up. 183 SZ outpatients were recruited from FondaMental Advanced Centers of Expertise for Schizophrenia cohort. Baseline and 1-year evaluations included sociodemographic data, current treatments, illness characteristics and standardized scales for clinical severity, adherence to treatment, quality of life, a large cognitive battery, and daily functioning assessment. Only 7 (3.8%) received a PI before the evaluation, and 64 (35%) have received at least one PI during the 1-year follow-up. Having had at least one PI during the follow-up has been associated in multivariate analyses with significantly higher improvement in positive and negative symptoms (respectively p =0.031; p = 0.011), mental flexibility (TMT B, p = 0.029; C-VF, p = 0.02) and global functioning (p =0.042). CBT and SST were associated with higher cognitive improvements, while CRT was associated with clinical improvement. These results have not been demonstrated before and suggest that the effect of each PI is larger than its initial target. The present study has confirmed the PIs' effectiveness in a large sample of community-dwelling SZ outpatients at 1 year follow-up. Efforts to improve access to PI should be reinforced in public health policies.

Real space maps of atomic transitions.

Considering the rapid technical development of transmission electron microscopes, we investigate the possibility to map electronic transitions in real space on the atomic scale. To this purpose, we analyse the information carried by the scatterer's initial and final state wave functions and the role of the different atomic transition channels for the inelastic scattering cross section. It is shown that the change in the magnetic quantum number in the transition can be mapped. Two experimental set-ups are proposed, one blocking half the diffraction plane, the other one using a cylinder lens for imaging. Both methods break the conventional circular symmetry in the electron microscope making it possible to detect the handedness of electronic transitions as an asymmetry in the image intensity. This finding is of important for atomic resolution energy-loss magnetic chiral dichroism (EMCD), allowing to obtain the magnetic moments of single atoms.

[Brucellosis with hepatic lesions: A diagnosis to keep in mind]. / Brucellose avec abcès hépatiques : un diagnostic à ne pas oublier.

INTRODUCTION: Brucellosis is a rare infection in France and its wide spectrum of clinical presentation can be a diagnostic challenge. CASE REPORT: We report here the case of a 76-year-old Tunisian-born woman referred for fatigue, weight loss, intermittent fever, and pain in the right upper quadrant, along with hepatic lesions on CT-scan, MRI and PET-FDG suggesting malignant lesions. However blood cultures were positive to Brucella melitensis leading to a diagnosis of hepatic brucelloma. CONCLUSION: Hepatic abscesses are rare in brucellosis. This infection has to be evoked in patients coming from endemic areas even with atypical manifestations.

Mice engineered for an obligatory Mdm4 exon skipping express higher levels of the Mdm4-S isoform but exhibit increased p53 activity.

Mdm4, a protein related to the ubiquitin-ligase Mdm2, is an essential inhibitor of tumor suppressor protein p53. In both human and mouse cells, the Mdm4 gene encodes two major transcripts: one encodes the full-length oncoprotein (designated below as Mdm4-FL), whereas the other, resulting from a variant splicing that skips exon 6, encodes the shorter isoform Mdm4-S. Importantly, increased Mdm4-S mRNA levels were observed in several human cancers, and correlated with poor survival. However, the role of Mdm4-S in cancer progression remains controversial, because the Mdm4-S protein appeared to be a potent p53 inhibitor when overexpressed, but the splice variant also leads to a decrease in Mdm4-FL expression. To unambiguously determine the physiological impact of the Mdm4-S splice variant, we generated a mouse model with a targeted deletion of the Mdm4 exon 6, thereby creating an obligatory exon skipping. The mutant allele (Mdm4(ΔE6)) prevented the expression of Mdm4-FL, but also led to increased Mdm4-S mRNA levels. Mice homozygous for this allele died during embryonic development, but were rescued by a concomitant p53 deficiency. Furthermore in a hypomorphic p53(ΔP/ΔP) context, the Mdm4(ΔE6) allele led to p53 activation and delayed the growth of oncogene-induced tumors. We next determined the effect of Mdm4(+/ΔE6) heterozygosity in a hypermorphic p53(+/Δ31) genetic background, recently shown to be extremely sensitive to Mdm4 activity. Mdm4(+/ΔE6) p53(+/Δ31) pups were born, but suffered from aplastic anemia and died before weaning, again indicating an increased p53 activity. Our results demonstrate that the main effect of a skipping of Mdm4 exon 6 is not the synthesis of the Mdm4-S protein, but rather a decrease in Mdm4-FL expression. These and other data suggest that increased Mdm4-S mRNA levels might correlate with more aggressive cancers without encoding significant amounts of a potential oncoprotein. Hypotheses that may account for this apparent paradox are discussed.

Synthesis and structure-activity relationship of new cephalosporins with amino heterocycles at C-7. Dependence of the antibacterial spectrum and beta-lactamase stability on the pKa of the C-7 heterocycle.

Cephalosporins with new aminobenzimidazole and aminoimidazoline heterocycles at C-7 have been synthesized starting with versatile C-7 isocyanide dihalide synthons. The aminobenzimidazoles have a broad spectrum of antibacterial activity, including Gram-positive and Gram-negative organisms, but possess limited beta-lactamase stability. In contrast, the aminoimidazolines have a narrow spectrum of antibacterial activity, limited to Gram-negative strains only, but possess outstanding beta-lactamase stability. Structure-activity relationships are discussed in terms of their dependence on the pKa of the C-7 amino heterocycle, basic C-7 residues giving cephalosporins with exceptional beta-lactamase stability.

Effects of [3H]-BIDN, a novel bicyclic dinitrile radioligand for GABA-gated chloride channels of insects and vertebrates.

1. The radiolabelled bicyclic dinitrile, [3H]-3,3-bis-trifluoromethyl-bicyclo[2.2.1]heptane-2,2-dicarbonitrile ([3H]-BIDN), exhibited, specific binding of high affinity to membranes of the southern corn rootworm (Diabrotica undecimpunctata howardi) and other insects. A variety of gamma-aminobutyric acid (GABA) receptor convulsants, including the insecticides heptachlor (IC50, 35 +/- 3 nM) and dieldrin (IC50, 93 +/- 7 nM), displaced [3H]-BIDN from rootworm membranes. When tested at 100 microM, 1-(4-ethynylphenyl)-4-n-propyl-2,6,7-trioxabicyclo[2.2.2]oct ane(EBOB), 4-t-butyl-2,6,7-trioxa-1-phosphabicy-clo[2.2.2]octane-1-thio ne (TBPS), 1-phenyl-4-t-butyl-2,6,7-trioxabicyclo[2.2.2]octane (TBOB) and picrotoxin failed to displace 50% of [3H]-BIDN binding to rootworm membranes indicating that the bicyclic dinitrile radioligand probes a site distinct from those identified by other convulsant radioligands. 2. Dissociation studies showed that dieldrin, ketoendrin, toxaphene, heptachlor epoxide and alpha and beta endosulphan displace bound [3H]-BIDN from rootworm membranes by a competitive mechanism. 3. Rat brain membranes were also shown to possess a population of saturable, specific [3H]-BIDN binding sites, though of lower affinity than in rootworm and with a different pharmacological profile. Of the insecticidal GABAergic convulsants that displaced [3H]-BIDN from rootworm, cockroach (Periplaneta americana) and rat brain membranes, many were more effective in rootworm. 4. Functional GABA-gated chloride channels of rootworm nervous system and of cockroach nerve and muscle were blocked by BIDN, whereas cockroach neuronal GABA(B) receptors were unaffected. 5. Expression in Xenopus oocytes of either rat brain mRNA, or cDNA-derived RNA encoding a GABA receptor subunit (Rdl) that is expressed widely in the nervous system of Drosophila melanogaster resulted in functional, homo-oligomeric GABA receptors that were blocked by BIDN. Thus, BIDN probes a novel site on GABA-gated Cl- channels to which a number of insecticidally-active molecules bind.

BIDN, a bicyclic dinitrile convulsant, selectively blocks GABA-gated Cl- channels.

BIDN (3,3-bis(trifluoromethyl)bicyclo[2,2,1]heptane-2,2-dicarbonitrile) at 10(-5) M blocked GABA-induced inhibitory postsynaptic potentials (IPSPs) recorded from an identified, giant interneuron (G12) of the cockroach (Periplaneta americana). The same concentration of this bicyclic dinitrile also blocked Cl- -mediated responses of G12 to GABA applied by pressure microinjection into the terminal abdominal ganglion neuropile containing dendrites of G12. BIDN (10(-5) M) was without effect on a response of G12 to GABA known to be mediated by a GABAB type receptor. In studies of the cell body of an identified motor neurone, the fast coxal depressor (Df) in the cockroach metathoracic ganglion, BIDN (10(-5) M) blocked reversibly an extrasynaptic GABA-gated Cl- channel, but not an extrasynaptic L-glutamate-gated Cl- channel. Glycine-gated Cl- channels observed when rat brain messenger RNA was expressed in Xenopus laevis oocytes were unaffected by BIDN at concentrations up to 10(-4) M, whereas this same concentration of BIDN completely blocked GABA-gated Cl- responses recorded from the same preparations. Unlike picrotoxin, which antagonises a variety of ligand-gated Cl- channels, to date BIDN has been found to block only Cl- channels gated by GABA, both in insect and vertebrate preparations.

DmGluRA, a Drosophila metabotropic glutamate receptor, activates G-protein inwardly rectifying potassium channels in Xenopus oocytes.

Xenopus oocytes were coinjected with cDNAs encoding the Drosophila melanogaster metabotropic glutamate receptor (DmGluRA) and two mammalian G-protein inwardly rectifying potassium channel subunits (GIRK1 and GIRK2). Glutamate and two vertebrate group II mGluR agonists (order of potency: LY 354740 > glutamate > DCG IV) elicited inwardly rectifying potassium currents. These inward currents were sensitive to cesium and barium. They were also blocked by two group II specific antagonists MCCG and APICA (IC50s 97.5 and 200 microM, respectively) and not affected by a group I antagonist (AIDA). Finally, the A-protomer of PTX reduced the glutamate-induced GIRK currents. This study is the first characterization of an invertebrate mGluR-mediated GIRK currents via a PTX-sensitive G protein.

Effects of a centipede venom fraction on insect nervous system, a native Xenopus oocyte receptor and on an expressed Drosophila muscarinic receptor.

Centipede venoms are complex protein mixtures; very few is known about their pharmacological actions. Application of a Scolopendra sp. venom fraction (SC1) on the cockroach giant axon induced an increase in the leak current correlated with a decrease in the membrane resistance, suggesting the presence in SC1 of components opening non-specific pores in the axonal membrane. On a cockroach central cholinergic synapse, microinjection of SC1 induced a small transient depolarization of the postsynaptic membrane, followed by a slow stable depolarization and a drastic decrease in the evoked subthreshold excitatory postsynaptic potential amplitude. A pretreatment of the ganglion with atropine or scopolamine reduced the amplitude of the SC1-induced depolarizing wave, suggesting a possible cholinergic muscarinic target. On control Xenopus oocytes, SC1 induced an inward oscillatory Ca2(+)-dependent Cl- current mediated through the activation of native lysophosphatidic acid receptors (LPAr). Indeed, pretreatment of oocytes with 1 microM N-palmitoyl-tyrosine phosphoric acid, a selective competitive antagonist of LPAr, decreased responses to SC1 by 70%. Application of SC1 to oocytes expressing a cloned Drosophila muscarinic receptor (Dml) induced a biphasic response comprising: (1) a large fast Cl- current that was abolished by pretreatment with atropine and scopolamine and (2) a slow and small oscillating Cl- current corresponding to the response observed in control oocytes. These observations confirm the presence of muscarinic agonists in SCI and reveal their direct action on an insect muscarinic receptor subtype homologous to mammalian M1-M3 receptors.

[Internal statistical validation of a quality of life questionnaire]. / Validation statistique interne d'un questionnaire de qualité de vie.

In this paper we present two different statistical approaches to evaluate the psychometric properties of a quality of life questionnaire. First the study of the factorial structure is briefly exposed. Then we present the unidimensional classical models. They are based on the linear relationship between the observed score and the true score. The definition of the reliability was first addressed in this classical framework. Its estimation with the Cronbach alpha coefficient is one important feature of the evaluation of an instrument. More recently, modern response theory gives a better statistical framework to deal with unidimensional latent traits. These models describe the probability of positive answer to an item as a function of the actual value of the latent trait and an item parameter. We expose the principles of the Rasch model: hypothesis, estimations methods and fit tests. Finally practical applications to the validation process of a questionnaire are explored with data from a study of a short French version of the SIP questionnaire.

A gradient of synaptic efficacy and its presynaptic basis in the cercal system of the cockroach.

1. The cerci of the cockroach Periplaneta americana bear longitudinal columns of wind-sensitive receptors which provide excitatory inputs to the giant interneurons (GIs) of the abdominal nerve cord. By using sound stimuli, we showed that spikes were more easily induced in the GIs from the most proximal than from the most distal receptors of the same column. 2. This was not due to a greater responsiveness of proximal sensilla to tones but to stronger synaptic connections; for the 3 largest GIs, the amplitude of the monosynaptic unitary EPSP tended to be all the higher as the stimulated sensillum was more proximal in each column. 3. The differences in EPSP size were due, at least partly, to presynaptic factors: a statistical analysis of the amplitude fluctuations of single-fibre EPSPs, showed that the amount of transmitter released per presynaptic impulse was larger for proximal than for distal sensory neurons in each column. 4. These differences in synaptic strength were correlated with differences in the structure of the afferent terminals. The location, the size and the shape of the axonal arbors are nearly the same for all sensory neurons of the same column, but proximal neurons arborize more profusely, and the terminal arbor of distal neurons is generally characterized by dorsal clusters of varicosities. 5. During postembryonic development, a decrease in the connection strength of 2 identified cercal neurons was accompanied by a retraction of ramifications on the medial side of their axonal arbor. 6. Possible mechanisms involved in the genesis and the remodelling of the gradient of synaptic strength are discussed in the light of available data and hypotheses relative to the development of ordered afferent connections.

The toxin Tx4(6-1) from the spider Phoneutria nigriventer slows down Na(+) current inactivation in insect CNS via binding to receptor site 3.

Tx4(6-1) a neurotoxic peptide from the venom of the aggressive South American 'armed' spider Phoneutria nigriventer, has been previously isolated and sequenced. It shows no detectable activity in mice but affects the peripheral nervous system of insects by stimulating glutamate release at the neuromuscular junction. Here we investigate possible interactions of the toxin with voltage-activated sodium channels (Na(v)). We confirm that it is ineffective on mammalian Na(v) channels, and establish that it competes with the alpha-like toxin 125I-Bom IV, for binding on the site 3 of insect Na(v) channel (IC(50) value around 25nM). The physiological consequences of this binding to the insect Na(v) channel are shown by electrophysiology: Tx4(6-1) prolongs evoked axonal action potentials (APs) (<500&mgr;s duration in control). Prolonged 8-10ms or 'plateau' 500-800ms APs accompanied by repetitive firing at 80-150Hz are recorded after 4-8min of toxin action. This modification of evoked activity is due to a slowing down of sodium current inactivation. Effects of Tx4(6-1) on sodium current are compared with those of a typical scorpion alpha-toxin and of some other spider toxins active on insect Na(v) channels. At the end of long voltage pulses, the maintained inward sodium current may represent 50% of the peak current after scorpion alpha-toxin but only about 8-10% after spider toxins. To understand the slight differences in the effects of alpha-scorpion and spider toxins on the insect Na(v) channel, structural studies of toxin-channels interactions would be necessary.