Construction and characterization of a BAC library for functional genomics in Xenopus tropicalis.

Large insert genomic DNA libraries are useful resources for genomic studies. Although the genome of Xenopus tropicalis stands as the amphibian reference genome because it benefitted from large-scale sequencing studies, physical mapping resources such as BAC libraries are lagging behind. Here we present the construction and characterization of a BAC library that covers the whole X. tropicalis genome. We prepared this BAC library from the genomic DNA of X. tropicalis females of the Adiopodoume strain. We characterized BAC clones by screening for specific loci, by chromosomal localization using FISH and by systematic BAC end sequencing. The median insert size is about 110kbp and the library coverage is around six genome equivalents. We obtained a total of 163,787 BAC end sequences with mate pairs for 77,711 BAC clones. We mapped all BAC end sequences to the reference X. tropicalis genome assembly to enable the identification of BAC clones covering specific loci. Overall, this BAC library resource complements the knowledge of the X. tropicalis genome and should further promote its use as a reference genome for developmental biology studies and amphibian comparative genomics.

A functional genomic approach to the study of the milking ability in dairy sheep.

To understand the mechanisms underlying milk ability and more precisely the kinetics of milk emission, we compared teat transcriptome profiles from Lacaune ewes in the tails of the milk flow phenotypic distribution. Two different arrays containing respectively 1896 and 13 168 PCR products selected from several tissue-specific cDNA libraries, including mammary gland, allowed the identification of 73 differentially expressed genes between teats from high and low milk flow ewes. Genes involved in muscle contraction were identified as over-expressed, and genes encoding collagen were found to be under-expressed in teats from low milk flow ewes. We confirmed this underexpression of COL1A1 and COL1A2 in low-milk flow ewes using RT-qPCR. These results suggest that milking ability may be due to the capacity of the teat sphincter to relax during mechanical milking. We propose that an optimal condition for mechanical milking may require proper relaxation of the teats. To our knowledge, this is the first transcriptomic analysis studying milking ability, using udder tissue for gene expression profiling, which demonstrates that mechanical milking ability is not only determined by morphological features but also by tissue composition.

Mesenteric panniculitis as a presentation of Whipple's disease: case report and review of the literature.

BACKGROUND: Whipple's disease is a rare, multi-organ disease caused by Tropheryma Whipplei. A classic presentation is characterized by arthropathy, diarrhea and weight loss but a broad spectrum of manifestations is possible. We present a case of a patient with mesenteric panniculitis as a manifestation of WD. A comprehensive review of the literature is provided. PATIENT: A 50 year old male presented at the outpatient clinic after an episode of fever and abdominal pain abroad. CT scan showed mesenteric infiltration with associated lymphadenopathies consistent with mesenteric panniculitis. After receiving 6 months of antibiotic therapy abdominal and joint pains improved. CONCLUSION: Clinicians should be aware of Whipple's disease. Mesenteric panniculitis is a rare presentation of this possible lethal infection. The golden standard for diagnosing WD is a PAS positive small bowel biopsy. Adequate antibiotic therapy is the cornerstone of treatment and usually leads to an amelioration of symptoms.

Terminal differentiation of goat mammary tissue during pregnancy requires the expression of genes involved in immune functions.

Terminal differentiation of mammary tissue into a functional epithelium that synthesizes and secretes milk occurs during pregnancy. The molecular mechanisms underlying this complex process are poorly understood, especially in ruminants. To obtain an overview of the ruminant mammary gland's final differentiation process, we conducted time-course gene expression analysis of five physiological stages: four during pregnancy (P46, P70, P90, and P110) and one after 40 days of lactation (L40). An appropriate loop experimental design was used to follow gene expression profiles. Using three nulliparous (pregnancy) or primiparous (lactation) goats per stage, we performed a comparison starting from nine dye-swaps and using a 22K bovine oligoarray. Statistical analysis revealed that the expression of 1,696 genes varied significantly at least once in the study. These genes fell into 19 clusters based on their expression profiles. Identification of biological functions with Ingenuity Pathway Analysis software revealed several similarities, in keeping with physiological stages described in mice. As in mice, expression of milk protein genes began at midpregnancy, and genes regulating lipid biosynthesis were induced at the onset of lactation. During the first half of pregnancy, the molecular signature of goat mammary tissue was characterized by the expression of genes associated with tissue remodeling and differentiation, while the second half was mainly characterized by the presence of messengers encoding genes involved in cell proliferation. A large number of immune-related genes were also induced, supporting recent speculation that mammary tissue has an original immune function, and the recruitment of migrating hematopoietic cells possibly involved in the branching morphogenesis of the mammary gland. These data hint that the induction of differentiation occurs early in pregnancy, very likely before P46. This period is therefore crucial for obtaining a healthy and productive mammary gland.

A multicentre, observational study on demographic and disease characteristics of patients seeking care for chronic hepatitis C in Belgium in 2016.

BACKGROUND AND STUDY AIMS: Direct-acting antivirals provide interferon-free treatments for chronic hepatitis C (CHC) virus infection. In Belgium, in 2016, access to these agents was limited to patients with advanced liver fibrosis stages F3 and F4. This study is the first to describe Belgium's patient population ineligible for interferon-free treatment. PATIENTS AND METHODS: This was an observational, cross-sectional, multicentre study that enrolled adult patients with CHC ineligible for interferon-free treatment. Patient data recorded at a single visit included demographic data, disease characteristics, comorbidities, co-medications, treatment status, and laboratory data. RESULTS: Three hundred and three patients from 16 centres in Belgium were included in the statistical analysis. On average, patients were aged 53.5 years and 50.2% were women ; 94.1% had health insurance and 99.0% resided in Belgium. The current hepatitis C virus (HCV) infection was the first infection for 96.0% of patients and the mean time since infection was 20.0 years. Liver fibrosis stage was F0 for 23.7%, F0/F1 or F1 for 38.3%, F1/F2 or F2 for 25.8%, F3 for 7.1%, and F4 for 5.1% of patients ; 28.4% of patients were CHC treatment-experienced. The main reason for ineligibility for interferon-free treatment was lack of reimbursement (84.8%). Other reasons included no treatment urgency or medical decision to wait (27.1%), waiting for future treatment option (8.3%), and no social insurance coverage (3.6%). CONCLUSIONS: This study provides recent data on the CHC patient population and disease characteristics in Belgium that could help medical communities and government agencies manage CHC disease burden.

Fouling and its reversibility in relation to flow properties and module design in aerated hollow fibre modules for membrane bioreactors.

Nowadays, most membrane bioreactors are using membranes submerged in the biomass and aeration in the concentrate compartment to limit or to control fouling. An important issue for the design of modules or membrane bundles in MBRs is to understand how the air/liquid flow is behaving and influencing fouling and its reversibility in relationship to the module properties. This paper focuses on an innovative and very specific process, in which HF membranes are put in a cartridge outside the activated sludge tank and a recycling loop is associated to the cartridge in order to decrease concentration of foulant species at the membrane surface and mass transfer resistance. Recycling operates with a very low liquid velocity in the module (a few cm.s(-1)) which constitutes a specificity of this process in terms of filtration operation. The aim of this study is to characterise two-phase flow and its effects on fouling and fouling reversibility at the scale of a semi-industrial bundle of outside/in hollow fibres, and as a function of bundle properties (packing density, fibre diameter), using specific methods to characterise the flow and fouling effects. Two modules were used showing a different packing density. Filtration was operated at constant permeate flux with clay suspension at 0.65 g.l(-1) in the same hydrodynamic conditions. Fouling kinetics and irreversibility were characterised by an adapted step method, and gas and liquid flows were characterised at global scale by residence time distribution analyses and gas hold-up. Fouling velocities are clearly influenced by gas velocity. The proportion of dead to total volume in the module is mainly affected by the liquid flow velocity and module design. The module with the higher fibre diameter and the lower packing density showed better performances in terms of fouling which was correlated with better flow properties.

Influence of subcutaneous injection of essential fatty acids on the stress-induced modifications of rat platelet aggregation and membrane lipid composition.

Membrane lipids play an important role in the function of blood platelets but the mechanisms by which the lipid composition of the platelet membrane is adjusted remain unclear. It has been shown that stress and poly-unsaturated fatty acids modified the lipid composition of blood plasma and platelet lipids, but very little is known about the effect of stress and fatty acids on membrane platelet lipid composition. The purpose of the present investigation was to study the influence of the essential fatty acids: linoleic, linolenic and arachidonic acids on the composition of the platelet membrane lipids of rats assigned to heat and restraint stress. It was shown that injections of polyunsaturated fatty acids decrease or suppress the stress-induced increase in platelet aggregation, suppress the stress-induced modification of the composition of the platelet membrane lipids and modify the fatty acid composition of the platelet membrane phospholipids.

Lipid analysis in nerve biopsy specimens of hypertrophic neuropathy.

We performed a lipid analysis on nerve biopsy specimens in two cases of degenerative hypertrophic neuropathy. Quantitative analysis of the major lipid classes, ie, cholesterol, cerebrosides, sulfatides, ethanolamine phospholipids, phosphatidyl-choline, phosphatidyl-serine, phosphatidyl-inositol, sphingomyelin, and gangliosides, were performed. The two cases exhibited extreme decreases in levels of lipids that could be related to the very low myelin content of these nerves. Cholesterol and phospholipid levels were especially reduced. Cerebrosides and sulfatides were not modified in the same proportion, as could have been predicted from the degree of demyelination. This relative glycolipid increase could be due to the very high Schwann cell proliferation.

[Substrates and products of fatty acid elongation in mouse brain microsomes]. / Substrats et produits de l'allongement des acides gras dans les microsomes de cerveaux de souris

In brain microsomes, palmitate and stearate elongation involve a membrane lipid-bound substrate. After elongation by malonyl-CoA, acyl-products are partially bound to proteins. Acyl-proteins are not found when endogenous fatty acid elongation takes place. In the dysmyelinating Quaking mouse mutants, "stearyl-membrane" substrate formation is normal; thus, the deficiency observed in very long chain fatty acid formation is not due to a lack in substrate formation.

Myelin consists of a continuum of particles of different density with varying lipid composition: major differences are found between normal mice and quaking mutants.

Mouse brain myelin consists of a continuum of particles of different densities, as shown by sucrose density gradient centrifugation. In normal animals most of the material (65 per cent) is concentrated between 0.6 and 0.7 M sucrose (the maximum being found at 0.66 M sucrose, corresponding to 23 per cent). The density differences among various myelin fractions are related to their protein/lipid ratios, as lighter fractions contain less protein and more lipid. Lipid analysis shows a decrease in the amount of every lipid from the lightest to the heaviest fraction: the light fraction is richer in phosphatidyl-ethanolamine, phosphatidyl-serine and cerebrosides. The distribution is highly abnormal in purified myelin from Quaking mutant ; very low quantities of myelin with normal density are found, but unexpected large amount of high density particles are found, possibly related to a "pre-myelin" material (oligodendrogial) processes which are not maturing into normal myelin).

Calcium content of mice brain lipids during myelination.

Calcium levels have been determined in brain of C57Bl mice and in the Quaking dysmyelinating mutant during the myelination period. In control mice, calcium content per gram brain is maximum at 20 days, at the acme of myelination, and decreases thereafter to reach a plateau at 30 days. This variation does not occur in the mutant where the level is 50% lower than maximum in controls and stable at 15 days after birth. In control mice, the variation may be related to the level or to the qualitative variation of some glycolipids and proteolipids as it disappears in lipid extract after Folch wash.

In vivo incorporation of exogenous stearic acid in synaptosomes: high occurrence of non-esterified fatty acids.

Subcutaneously injected stearic acid is taken up by the brain through the 'blood-brain barrier' and is incorporated into synaptosomal lipids (as well as into other brain compartments). Phospholipids are potent acceptors (choline phosphatides, ethanolamine phosphatides, serine phosphatides). Moreover a high level of radioactivity was found in non-esterified fatty acids.

Analysis of the major lipid classes in human peripheral nerve biopsies. Age group differences and abnormalities of ganglioside level in perhexiline maleate therapy.

We report here the results of a simple and reproducible technique which can be used in semi-routine analysis of peripheral nerve biopsy specimens, so as to have a quantitative analysis of the major lipid classes, i.e. cholesterol, cerebrosides, ethanolamine phospholipids, phosphatidyl-choline, phosphatidyl-serine + phosphatidylinositol, sphingomyelin and gangliosides. Glycolipid hexoses, cholesterol and total phospholipids have been compared in different age groups. Although all lipid classes increased from the younger to the older age group, the molar ratio of cholesterol to phospholipid differed less than the glycolipid to phospholipid ratio. Both increased significantly, even between age group 10--16 and older patients (36, 54, 61, 68, 72 and 73 years old). Although individual variations in lipid content are noteworthy, it must be emphasized that evolution with age of the lipid composition must be taken into account. Furthermore, this study confirms and extends earlier findings of increased ganglioside levels in some cases of peripheral neuropathies observed during perhexiline maleate therapy where characteristic lipid-like polymorphous inclusions have been demonstrated.

Zinc and DNA fragmentation in keratinocyte apoptosis: its inhibitory effect in UVB irradiated cells.

Zinc has been shown to have antioxidant properties and to exhibit inhibitory effects on apoptosis. In this work we investigated the effect of zinc on DNA integrity and on apoptosis of HaCaT keratinocytes. Cells were submitted to zinc deprivation by a diffusible zinc chelator, (N,N,N',N'-tetrakis (2-pyridylmethyl)ethylenediamine) (TPEN) or supplied with zinc chloride and submitted to UVB radiation. After cell exposure to TPEN for 2 h, strand breaks significantly impaired DNA resistance to alkaline denaturation. DNA strand breaks induced by a 6 h TPEN application were significantly prevented if zinc chloride was supplied together with the chelator. TPEN also generated, after 4-6 h of application, cytoplasmic histone-associated DNA fragments (mononucleosomes and oligonucleosomes), features of cell death by apoptosis. Moreover, UVB irradiation led to early DNA strand breaks and to an increase in cytoplasmic nucleosomes which was maximum 10 h after irradiation. These effects were prevented by the supply of zinc chloride (0.1 mM) in the culture medium. These results suggest that zinc ions interfere with the apoptosis process at an early stage, by decreasing DNA damage able to trigger apoptosis.

[Neurological disorders and perhexiline maleate therapy. Clinical study of 10 cases. Neuropathological, pharmacocinetic and biochemical studies (author's transl)]. / Manifestations neurologiques en rapport avec le traitement par le maléate de perhexiline. Etude clinique d'une série de 10 cas. Documents neuropathologiques, pharmacocinétiques et biochimiques.

Ten new cases of perhexiline induced peripheral neuropathies are reported. The authors emphasize the possible association of other neurological disorders: cerebellar symptoms in one case, complex tremor in two other cases, marked decrease of photomotor reflexes in one case and disgeusia in another one. The pharmacocinetic study of 4 cases revealed the presence of a low metabolism of the drug in one of them. Polymorphous inclusions have been seen in Schwann cell and endothelial cell cytoplasm in the three patients with electron microscopic study of the nerves. The pathological study of one case showed the demyelination of spinal cord posterior columns. In another case, who died from hepatic coma, the biochemical study of cerebral lipids revealed the low values of cerebrosides and sulfatides in cerebellum and cerebral white matter.