Biochemical mediators in acute respiratory distress syndrome (ARDS) after burning injury

in Paubert-Braquet (Ed.) Lipids mediators in the immunology of shock (1987)

Biochemical Study of Collagen in Adult Groin Hernias

in Journal of Surgical Research (2001), 95(2), 107-13

BACKGROUND: Previous works have suggested that a defect in collagen fiber structure may play a role in inguinal hernia formation. These studies focused mainly on the rectus sheath or the skin, while only ... [more ▼]

BACKGROUND: Previous works have suggested that a defect in collagen fiber structure may play a role in inguinal hernia formation. These studies focused mainly on the rectus sheath or the skin, while only few reports dealt with the transversalis fascia. According to these findings and to our previous biomechanical and histological studies suggesting that a connective tissue pathology could play a role in the genesis of groin hernias, we performed a biochemical investigation of the collagen in the transversalis fascia and rectus sheath. MATERIALS AND METHODS: The samples were collected from 40 adult patients with uni- or bilateral hernias and from 20 control subjects without hernia (autopsies and organ donors). A constant area of tissue was taken by using a calibrator. The wet and dry weights per 100 mm(2) were determined and the total collagen concentration as well as its sequential extractibility in NaCl, acetic acid, and pepsin was measured. The ratios of alpha(1)/alpha(2) chains (I) and of type I/III collagen were assessed by polyacrylamide gel electrophoresis. RESULTS: Samples collected in the control and patient sheaths showed an increased wet weight per 100 mm(2) in the patients. The wet and dry weights per unit area were increased in the patient fascias. The collagen concentration was increased in the indirect hernias. The fascias from the direct hernias (DH) presented a significantly increased collagen extractibility after pepsin digestion (5.6%), when compared to the control fascias (2.6%). The extractibility was 3.4% in the nonherniated (NH) sides. The qualitative study (ratios alpha(1)/alpha(2) (I) and I/III collagen) showed no difference between the fascia groups. CONCLUSIONS: The significant increase of collagen extractibility with pepsin in the DH fascias and at a lesser degree in the NH fascias suggests that molecular alterations of collagen could be involved in the genesis of groin hernias. This connective tissue pathology would express preferentially its effects in the inguinal region, since we have observed no major difference between the rectus sheaths of controls and those of patients. [less ▲]

Biochemical, genetic and molecular characterization of new respiratory-deficient mutants in Chlamydomonas reinhardtii.

in Plant Molecular Biology (1992), 18

Eight respiratory-deficient mutants of Chlamydomonas reinhardtii have been isolated after mutagenic treatment with acriflavine or ethidium bromide. They are characterized by their inability to grow or ... [more ▼]

Eight respiratory-deficient mutants of Chlamydomonas reinhardtii have been isolated after mutagenic treatment with acriflavine or ethidium bromide. They are characterized by their inability to grow or their very reduced growth under heterotrophic conditions. One mutation (Class III) is of nuclear origin whereas the seven remaining mutants (Classes I and II) display a predominantly paternal mt- inheritance, typical of mutations residing in the mitochondrial DNA. Biochemical analysis has shown that all mutants are deficient in the cyanide-sensitive cytochrome pathway of the respiration whereas the alternative pathway is still functional. Measurements of complexes II + III (antimycin-sensitive succinate-cytochrome c oxido-reductase) and complex IV (cytochrome c oxidase) activities allowed to conclude that six mutations have to be localized in the mitochondrial apocytochrome b (COB) gene, one in the mitochondrial cytochrome oxidase subunit I (COI) gene and one in a nuclear gene encoding a component of the cytochrome oxidase complex. By using specific probes, we have moreover demonstrated that five mutants (Class II mutants) contain mitochondrial DNA molecules deleted in the terminal end containing the COB gene and the telomeric region; they also possess dimeric molecules resulting from end-to-end junctions of deleted monomers. The two other mitochondrial mutants (Class I) have no detectable gross alteration. Class I and Class II mutants can also be distinguished by the pattern of transmission of the mutation in crosses. An in vivo staining test has been developed to identify rapidly the mutants impaired in cyanide-sensitive respiration. [less ▲]

Biochemistry and comparative genomics of SxxK superfamily acyltransferases offer a clue to the mycobacterial paradox: Presence of penicillin-susceptible target proteins versus lack of efficiency of penicillin as therapeutic agent

in Microbiology & Molecular Biology Reviews (2002), 66(4), 702-738

The bacterial acyltransferases of the SxxK superfamily vary enormously in sequence and function, with conservation of particular amino acid groups and all-alpha and alpha/beta folds. They occur as ... [more ▼]

The bacterial acyltransferases of the SxxK superfamily vary enormously in sequence and function, with conservation of particular amino acid groups and all-alpha and alpha/beta folds. They occur as independent entities (free-standing polypeptides) and as modules linked to other polypeptides (protein fusions). They can be classified into three groups. The group I SxxK D,D-acyltransferases are ubiquitous in the bacterial world. They invariably bear the motifs SxxK, SxN(D), and KT(S)G. Anchored in the plasma membrane with the bulk of the polypeptide chain exposed on the outer face of it, they are implicated in the synthesis of wall peptidoglycans of the most frequently encountered (4-->3) type. They are inactivated by penicillin and other beta-lactam antibiotics acting as suicide carbonyl donors in the form of penicillin-binding proteins (PBPs). They are components of a morphogenetic apparatus which, as a whole, controls multiple parameters such as shape and size and allows the bacterial cells to enlarge and duplicate their particular pattern. Class A PBP fusions comprise a glycosyltransferase module fused to an SxxK acyltransferase of class A. Class B PBP fusions comprise a linker, i.e., protein recognition, module fused to an SxxK acyltransferase of class B. They ensure the remodeling of the (4-->3) peptidoglycans in a cell cycle-dependent manner. The free-standing PBPs hydrolyze D,D peptide bonds. The group II SxxK acyltransferases frequently have a partially modified bar code, but the SxxK motif is invariant. They react with penicillin in various ways and illustrate the great plasticity of the catalytic centers. The secreted free-standing PBPs, the serine beta-lactamases, and the penicillin sensors of several penicillin sensory transducers help the D,D-acyltransferases of group I escape penicillin action. The group III SxxK acyltransferases are indistinguishable from the PBP fusion proteins of group I in motifs and membrane topology, but they resist penicillin. They are referred to as Pen(r) protein fusions. Plausible hypotheses are put forward on the roles that the Pen(r) protein fusions, acting as L,D-acyltransferases, may play in the (3-->3) peptidoglycan-synthesizing molecular machines. Shifting the wall peptidoglycan from the (4-->3) type to the (3-->3) type could help Mycobacterium tuberculosis and Mycobacterium leprae survive by making them penicillin resistant. [less ▲]

Biochemistry of beta-lactamases and penicillin-binding proteins - Discussion

in Reviews of Infectious Diseases (1988), 10(4), 739-742

Biochemistry of the Bacterial Wall Peptidoglycan in Relation to the Membrane

in FEBS Symposium (1970), 20

Biochemistry of thiamine and thiamine phosphate compounds

in Lennarz, W. J.; Lane, M. D. (Eds.) The Encyclopedia of Biological Chemistry, vol 1 (2013)

Biochemostratigraphy of the upper Frasnian in the Namur–Dinant Basin, Belgium: Implications for a global Frasnian–Famennian pre-event

in Palaeogeography, Palaeoclimatology, Palaeoecology (2012), 313-314

The Upper Frasnian sequence of the Namur–Dinant Basin in southern Belgium consists of mixed siliclastic–carbonate succession of a ramp setting, where the sequence spans the rhenana–linguiformis conodont ... [more ▼]

The Upper Frasnian sequence of the Namur–Dinant Basin in southern Belgium consists of mixed siliclastic–carbonate succession of a ramp setting, where the sequence spans the rhenana–linguiformis conodont zones. Earlier studies investigated the chemostratigraphic variations during the Frasnian-Famennian event, but little has been yet known about the nature of the counterpart variations that immediately preceded that time interval. Despite the scarcity of well-preserved brachiopods, sixty–one calcitic shells were collected mainly from beds of the Neuville and Les Valisettes formations (Lower and Upper rhenana zones), to investigate biochemostratigraphic profiles of oxygen-, carbon-isotope and rare earth element (REE) variations of the time interval immediately before the Frasnian-Famennian boundary. The δ18O and δ13 C values of the well-preserved shells range from − 9.5 to − 5.6 ‰ VPDB (− 7.7 ± 1.1, n = 33) and from − 1.8 to 3.8 ‰ VPDB (1.1 ± 1.7, n = 33), respectively, which are within the documented global values. The C- and O-isotope profiles exhibit parallel shifts, particularly at the top of the Neuville Formation (top of the Lower rhenana Zone), which are associated with a sea-level rise and shrinkage in the brachiopod community. Also, the Th/U (0.9 ± 0.6, n = 16) and Ce/Ce* (2.2 ± 0.5, n = 16) ratios suggest deposition under reducing conditions consistent with sea transgression. [less ▲]

Bioclimate-based Plant Affinity Groups and Regional Biome Simulation of China (In Chinese)

in Quaternary Sciences (2009), 29

Biocompatibilidad de nuevos policationes sintéticos sobre las propiedades mecánicas y morfológicas de la membrana eritrocitaria

Poster (2006, September 25)