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J M Verdier

Publications and source records attributed to J M Verdier.

At least 37 records · Page 2Linked to original sources
PubMed1992

Preliminary treatment of urinary proteins improves electrophoretic analysis and immunodetection.

Analysis of urinary protein composition is an important tool in studies on renal physiology and physiopathology. Urine is, however, a complex mixture containing, besides protein, a variety of compounds such as salts, peptides, oligosaccharides, and glycosaminoglycans. Some of these compounds interfere with the electrophoretic migration of protein in sodium dodecyl sulfate-polyacrylamide gels and prevent correct analysis of the protein pattern. We describe a simple method for extracting urinary proteins that considerably improves their electrophoretic migration and subsequent immunodetection. This treatment involves ammonium sulfate fractionations (for precipitating proteins), EDTA (for inhibiting protein aggregation), and HCl hydrolysis (for removing glycosylaminoglycans). Recovery during extraction was found to be almost quantitative for total protein and three representative proteins: albumin, alpha 1-glycoprotein acid, and beta 2-microglobulin.

Albuminuria↗
PubMed1991

Rat pancreatic stone protein messenger RNA. Abundant expression in mature exocrine cells, regulation by food content, and sequence identity with the endocrine reg transcript.

We used a cDNA encoding the human pancreatic stone protein (PSP-S), the secretory inhibitor of CaCO3 crystal growth, as a probe for cloning rat PSP-S messenger RNA. Overlapping clones gave a mRNA sequence of 783 nucleotides encoding a preprotein of 165 amino acids including a prepeptide of 21 amino acids. Rat and human PSP-S showed 70% identity, and the mature proteins had the same length. PSP-S mRNA concentration was measured in the pancreas of rats adapted to diets containing 15, 25, or 70% protein. Compared with the 15% protein diet, concentration increased 3 and 12 times with the diets with 25 and 70% protein, respectively, which is 3 times higher than for serine proteases. A complete sequence identity was observed between the rat PSP-S transcript and the reg mRNA described by Terazono et al. (Terazono, K., Yamamoto, H., Takasawa, S., Shiga, K., Yonemura, Y., Tochino, Y., and Okamoto, H. (1988) J. Biol. Chem. 263, 2111-2114), which is expressed in regenerating pancreatic islets but not in mature islets. A specific role of the reg protein in islet regeneration was suggested. We found that PSP-S (reg) mRNA concentration was indeed increased in isolated regenerating islets. Yet, a transient increase was also observed in exocrine tissue during the initial phase of regeneration following pancreatectomy or acute pancreatitis, suggesting increased expression during cell dedifferentiation. It is concluded that, in mature pancreas, expression of the reg/PSP-S gene occurs primarily in acinar cells. The gene product, which encodes a secretory protein inhibiting CaCO3 crystal growth in juice, is unlikely to play a specific role in islet regeneration.

Amino Acid Sequence↗
PubMed1990

Preparation and characterization of yeast nuclear extracts for efficient RNA polymerase B (II)-dependent transcription in vitro.

We present a reproducible method for the preparation of nuclear extracts from the yeast Saccharomyces cerevisiae that support efficient RNA polymerase B (II)-dependent transcription. Extracts from both a crude nuclear fraction and Percoll-purified nuclei are highly active for site-specific initiation and transcription of a G-free cassette under the Adenovirus major late promoter. At optimal extract concentrations transcription is at least 5 times more efficient with the yeast extracts than with HeLa whole cell extracts. We show that the transcriptional activity is sensitive to alpha-amanitin and to depletion of factor(s) recognizing the TATA-box of the promoter. The in vitro reaction showed maximal activity after 45 min, was very sensitive to Cl-, but was not affected by high concentrations of potassium. We find that the efficiency of in vitro transcription in nuclear extracts is reproducibly high when spheroplasting is performed with a partially purified beta 1,3-glucanase (lyticase). Therefore a simplified method to isolate the lyticase from the supernatant of Oerskovia xanthineolytica is also presented.

Amanitins↗
PubMed1990

A yeast homolog of the human UEF stimulates transcription from the adenovirus 2 major late promoter in yeast and in mammalian cell-free systems.

We report the identification and purification of a yeast factor functionally homologous to the human upstream element factor (UEFh). Although the yeast protein (UEFy) has a higher molecular weight than the HeLa UEF (60 kD versus 45 kD) both have identical DNA-binding properties: the purified UEFy recognizes the Adenovirus 2 (Ad2) major late promoter upstream element (MLP-UE; from nucleotide -49 to -67) as well as the IVa2 upstream element (IVa2-UE; from nucleotide -98 to -122) with a higher affinity for the MLP-UE than for the IVa2-UE. Based on its DNA binding specificity, size and thermostability, the UEFy protein appears also similar or equivalent to the centromere binding protein CP1. In a competition assay with oligonucleotides containing the MLP-UE binding site, a drastic reduction of Ad2 MLP transcription was observed both in a HeLa and in a yeast cell free system, which was restored by addition of either the purified UEFh or UEFy proteins. We conclude that both UEFh and UEFy activate transcription from the Ad2 MLP upon binding to the upstream element, whatever is the in vitro cell-free system (yeast or HeLa). This indicate that some regulatory function represented by the upstream element and its cognate factor, is well conserved between human and yeast.

Adenoviruses, Human↗
PubMed1984

Carcinogen-induced mutation spectrum in wild-type, uvrA and umuC strains of Escherichia coli. Strain specificity and mutation-prone sequences.

Forward mutations induced by the ultimate carcinogen N-acetoxy-N-2-acetylaminofluorene (N-Aco-AAF) in the tetracycline resistance gene carried on plasmid pBR322 are shown to be dependent upon the induction of the host SOS functions in wild-type and umuC Escherichia coli cells. The mutation frequency in the umuC strain is equal to about 40% of the mutation frequency observed in the umu+ background. In the excision-repair-deficient uvrA mutant strain the mutagenic response is the same as in SOS-induced wild-type cells whether or not the uvrA bacteria are SOS-induced. Equal mutation frequencies are obtained in both the wild-type and the uvrA strains for equal modification levels although the survival of AAF-modified plasmid DNA is greatly reduced in the uvrA strain as compared to the wild-type strain. Sequence analysis of the mutations reveals that more than 90% of the N-Aco-AAF-induced mutations are frameshift mutations. Two types of mutational hotspots are observed occurring either at repetitive sequences or at non-repetitive sequences. Both types of mutants appear at similar locations and frequencies in both the wild-type and the uvrA strains. On the other hand, only the non-repetitive sequence mutants are obtained in the umuC background. These non-repetitive sequence mutants preferentially occur within the sequence 5' G-G-C-G-C-C 3' (the NarI restriction enzyme recognition sequence). The analysis of the -AAF binding spectrum to the same DNA fragment shows that there is no direct correlation between the modification spectrum and the mutation spectrum. We suggest that certain sequences are "mutation-prone" in the sense that only these sequences can be efficiently mutated as the result of an active processing mediated by specific proteins. When a sequence is said to be mutation-prone it probably corresponds to a particular structure that is induced within this sequence as a result of the binding to the DNA of the mutagen. This sequence-specific conformational change is the substrate for the protein(s) that fixes the mutation. The mutagenic processing pathway(s) is part of the cellular response to DNA-damaging agents (the so-called SOS response). Two pathways for frameshift mutagenesis are suggested by the data: an umuC-dependent pathway, which is involved in the mutagenic processing of lesions within repetitive sequences; an umuC-independent pathway responsible for the fixation of mutations within specific non-repetitive sequences.

2-Acetylaminofluorene↗
PubMed1982

[Candida albicans spondylitis. Review of the literature apropos of a case with study of bone penetration of 5-fluorocytosine].

In spite of the development in cases of deep mycoses, cases of osteoarthritis with Candida remain rare (only thirty seven cases reported). Among these, ten observations of spondylodiscitis have been collected and the authors report a new case where Candida albicans was isolated in the discovertebral focus through bone puncture. This spondylodiscitis occurring in a leukemic patient receiving antibiotics, corticosteroids, cytostatics drugs and radiotherapy, was treated successfully by an association of Amphotericin B-5-Fluorocytosine. The authors take this opportunity to report the main characteristics of the ten previously described cases specifying the rules for the uses of fungicidal drugs in the treatment of deep mycoses and for the first time, they study simultaneously seric concentration, penetration into healthy bone and into discovertebral focus of the 5-Fluorocytosine. They also justify their preference for the association of Amphotericin B-5-Fluorocytosine as a "first line" treatment after confirming the sensitivity of the strain to 5-Fluorcytosine.

Amphotericin B↗
PubMed1980

[Beta-2-microglobulin and rheumatoid factor levels in the synovial fluid (author's transl)].

The object of this study was to determine whether levels of beta-2-microglobulin and of rheumatoid factor measured by an enzyme-immunoassay allowed good discrimination between inflammatory and degenerative arthropathies. A multiparametric study of synovial fluid was performed on 85 specimens from patients with rheumatoid arthritis, chondrocalcinosis, mechanical arthritis and traumatic arthopathies. A beta-2-microglobulin level of less than 4 mg/l is a result very mich in favor of a non-inflammatory arthropathy (48/49 cases). The quantification of intra-articular rheumatoid factor allows for reclassification in the context of sero-negative rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1976

[Radiologic study of the jaws in the course of myeloma. A propos of 111 cases].

The authors studied the radiological manifestations in bone in 111 patients suffering from multiple bone myeloma. The analysis deals mainly with the maxilla, and in particular with the lower maxilla which was the site of myelomatous lesions in 49 cases. The authors describe two different types of image observed and the radiological methods used, and they discuss the principal problems of diagnosis. They emphasize the diagnostic value of systematic study of this site, which may be solitary, without a concomitant lesion of the cranial dome in particular.

Adult↗
PubMed1976

[The hemarthroses of articular chondrocalcinosis].

Spontaneous haemarthrosis may occur during the evolution of articular chondrocalcinosis. It occurs mainly in older women and involves the knee in particular. The disorder may recur in the same or in different joints. A study of 11 case histories and counts of red blood corpuscles in samples of synovial fluid confirm that bleeding occurs more readily in chondrocalcinosis than in arthrosis alone. The proposed mechanism of haemarthrosis is only a hypothesis, but it is possible to imagine the onset of microcrystalline flow in a joint that is senile and affected by arthrosis. It is suspected that repeated haemarthrosis favours an oseolytic evolution in certain cases of chondrocalcinosis.

Aged↗