Cigarettes pendant la grossesse,poids de naissance et mortalité périnatale

This study is based on a 10% random sample of medical certifications of birth in Quebec in 1970-71 and on additional information obtained from perinatal death certificates and birth registrations. Smoking in pregnancy significantly reduced the average birth weight after 35 weeks of gestation. It increased the risk of perinatal death by 24%. This increase was concentrated in the age groups under 25 and 35 +, in the parity groups 0 and 4 + and among women with less than 12 years of schooling. The proportion of mothers smoking during pregnancy was 43.2% and ranged as high as 62.2% among those under 20 with less than eight years of schooling. These depressingly high percentages imply that new educational approaches aimed particularly at high-risk groups should be developed and evaluated.     

Large scale purification, nucleotide binding properties, and ATPase activity of the MalK subunit of Salmonella typhimurium maltose transport complex.

The malK gene, encoding a membrane-associated component of the maltose transport complex of Salmonella typhimurium was cloned into an expression vector downstream of the promoters lambda pR and lambda pL and a strong translation initiation region. Escherichia coli strain JM109 harboring the resulting plasmid pCW14 synthesized a protein of apparent molecular mass of 43 kDa upon temperature shift, as demonstrated by sodium dodecyl sulfate-gel electrophoresis. The identity of the protein was determined by N-terminal amino acid sequencing. The overproduced protein was sequestered in inclusion bodies as revealed by electron microscopy. The protein was purified to homogeneity on a large scale by disrupting the cells with a passage through a Ribi press, solubilizing the inclusion bodies with urea, and subsequent chromatography on Red Agarose. Purified MalK, as the membrane-bound MalK protein could be covalently modified by [gamma-32P]8-azido-ATP. Furthermore, the purified protein bound [gamma-32P] ATP with a dissociation constant of 150 microM and exhibited ATPase activity, which was stimulated by dimethyl-sulfoxide and inhibited by ADP.     

Individual variations of the seven carbohydrate components of human erythrocyte membrane during aging in vivo

The contents of fucose, mannose, galactose, glucose, 2-acetamido-2-deoxy-d-glucose and -d-galactose, and sialic acid, when the results were expressed as nmol per mg of membrane dry-weights, were found to be significantly lower in the membranes of old erythrocytes than in the membranes of young ones. No significant difference was found between young and old membranes when the compositions were expressed as residues per one hundred carbohydrate residues, suggesting that a homogeneous decrease of the carbohydrate moieties may occur during aging in vivo.     

Lysophospholipid receptors: Signalling, pharmacology and regulation by lysophospholipid metabolism

The lysophospholipids, sphingosine-1-phosphate (S1P), lysophosphatidic acid (LPA), sphingosylphosphorylcholine (SPC) and lysophosphatidylcholine (LPC), activate diverse groups of G-protein-coupled receptors that are widely expressed and regulate decisive cellular functions. Receptors of the endothelial differentiation gene family are activated by S1P (S1P_1-5) or LPA (LPA_1-3); two more distantly related receptors are activated by LPA (LPA_4/5); the GPR_3/6/12 receptors have a high constitutive activity but are further activated by S1P and/or SPC; and receptors of the OGR1 cluster (OGR1, GPR4, G2A, TDAG8) appear to be activated by SPC, LPC, psychosine and/or protons. G-protein-coupled lysophospholipid receptors regulate cellular Ca²⁺ homoeostasis and the cytoskeleton, proliferation and survival, migration and adhesion. They have been implicated in development, regulation of the cardiovascular, immune and nervous systems, inflammation, arteriosclerosis and cancer. The availability of S1P and LPA at their G-protein-coupled receptors is regulated by enzymes that generate or metabolize these lysophospholipids, and localization plays an important role in this process. Besides FTY720, which is phosphorylated by sphingosine kinase-2 and then acts on four of the five S1P receptors of the endothelial differentiation gene family, other compounds have been identified that interact with more ore less selectivity with lysophospholipid receptors.