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M Chartier

Publications and source records attributed to M Chartier.

At least 37 records · Page 2Linked to original sources
PubMed1985

Lysis protein encoded by plasmid ColA-CA31. Gene sequence and export.

A gene, cal, coding for a polypeptide needed for the release of colicin A from Escherichia coli cells has been identified by transposon insertion. The cal gene was located on the ColA plasmid map adjacent to cai, the gene coding for colicin A immunity protein, and therefore 592 bases downstream from caa, the structural gene for colicin A. Transcription of cal is in the same direction as caa, that is in the opposite direction to cai. Its sequence has been determined and the predicted amino acid composition features a basic N-terminal end followed by a serie of hydrophobic residues similar to the signal sequence in precursors of exported proteins. The C-terminal part also contains a core of hydrophobic residues. The overall amino acid sequence of the cal protein is homologous to that of lytic proteins encoded by the related plasmids pColE1, and pCloDF13. The cal protein has been identified on urea-SDS-polyacrylamide gels by selective labelling with various radioactive amino acids and its synthesis is co-induced with that of colicin A. The cal protein undergoes slow processing with loss of the N-terminal "signal" region and the mature form is released into the medium together with colicin A.

Amino Acid Sequence↗
PubMed1984

Prenatal diagnosis of congenital rubella.

In an attempt at prenatal diagnosis of fetal infection after primary rubella infection before 18 weeks of pregnancy fetal blood was taken by direct puncture under ultrasound guidance at 20-26 weeks of pregnancy from eighteen patients. Total IgM was assayed by radial immunodiffusion and rubella-specific IgM by IgM capture immunoassay. Rubella-specific IgM was detected in twelve of the eighteen fetuses. The parents decided whether to continue or terminate the pregnancy on the basis of the time of onset of maternal rubella. All six pregnancies in which rubella occurred before 12 weeks of gestation were terminated. Of the six with rubella after 12 weeks two were terminated. Among the six fetuses negative for rubella-specific IgM, five had no rubella-specific IgM at birth and no persistent IgG but one was found to be infected at birth; this false-negative diagnosis was due to sampling too early during pregnancy.

Antibody Specificity↗
PubMed1983

Complete nucleotide sequence of the structural gene for colicin A, a gene translated at non-uniform rate.

The complete nucleotide sequence of the structural gene for colicin A has been established. This sequence consists of 1776 base-pairs. According to the predicted amino acid sequence, the colicin A polypeptide chain comprises 592 amino acids and has a molecular weight of 62,989. The amino-terminal part is rich in proline and glycine and accordingly secondary structure prediction indicates that this region (1 to 185) is beta-structured. The rest of the molecule (residues 186 to 592) is very rich in alpha-helix. An uncharged amino acid sequence of 48 residues is located in the C-terminal part of the molecule, which is involved in the membrane depolarization caused by colicin A. A similar region has been found in colicin E1, which has the same mode of action as colicin A. Three peptides of these bacteriocins were found to be homologous, but a comparison of the bacteriocin genes did not reveal any significant homology out of the corresponding regions. The codon usage of both genes, however, exhibits some similarity and is quite different from that of genes coding for highly or weakly expressed proteins of Escherichia coli.

Amino Acid Sequence↗
PubMed1983

Nucleotide sequence of promoter, operator and amino-terminal region of caa, the structural gene of colicin A.

The nucleotide sequence of 378 bp covering the promoter-operator regions and the region coding for the N-terminal portion of the colicin A gene was determined. These assignments were made possible by the determination of the N-terminal 12 amino acids of the colicin A protein. DNA sequence homologies between operator regions of recA, lexA, uvrA, uvrB, cea and caa genes are discussed.

Amino Acid Sequence↗
PubMed1980

Renal lesions in the hypertensive syndromes of pregnancy: immunomorphological and ultrastructural studies in 114 cases.

One hundred and fourteen women presenting during pregnancy with an abnormally high blood pressure and/or proteinuria had a renal biopsy usually on the 8th day following delivery. The pathological specimens were examined by light and/or electron and/or immunofluorescence microscopy. Forty-one cases were studied with all three techniques. The patients could be allocated to six groups on the basis of clinical criteria. The first two groups (52 patients) showed the typical clinical and pathological features of classical preeclampsia. The remaining 62 women (four groups) had isolated hypertension, and, of these, 42 had a renal pathological pattern similar to that of preeclampsia. These 42 patients also had persistent hyperuricemia. Thus in pregnancy, hypertension and persistently elevated uric acid levels are indicative of glomerular lesions of "pregnancy induced nephropathy".

Adult↗
PubMed1979

Measurement of plasma human chorionic gonadotropin (hCG) and beta-hCG activities in the late luteal phase: evidence of the occurrence of spontaneous menstrual abortions in infertile women.

Plasma luteinizing hormone (LH-human chorionic gonadotropin (hCG) and beta-hCG activities were measured during the late luteal phase in 321 cycles of 147 infertile women. In 71 cycles the hCG measurement permitted the diagnosis of pregnancy between the 10th and 14th days after the thermal nadir. The slope of the regression line derived from hCG levels during the first 22 days of pregnancy was significantly lower in pregnancies which aborted before the 60th day than in normal pregnancies (P less than 0.01). Among 72 cycles ended by apparently normal menses which exhibited an LH-hCG activity at least equal to 7 mIU of hCG/ml during the late luteal phase, the beta-hCG activity was measured in 49 cycles during which hCG had not been given. Significant beta-hCG activity (greater than or equal to 4 mIU of hCG/ml) was detected in 19 cases. This finding supports the assumption that secretory trophoblastic tissue had been present and that spontaneous menstrual abortions had occurred in these women.

Abortion, Spontaneous↗
PubMed1975

[Diagnosis of pregnancy before the menstrual period is delayed. Interest of the determination of plasma chorionic gonadotropin (HCG) in fertility disorders].

Estimating plasma HCG levels in the last days of the menstrual cycle have very early diagnosis of pregnancy. In 86 cycles occurring in 65 women being treated for sterility the levels were estimated between the 10th and the 15th day following the low point in the temperature curve for the purpose of trying to estimate the practical use of this method. In 30 cycles studied one case of fertilisation took place and was confirmed by the evolution of a pregnancy. From the 11th day onwards with the exception of one solitary case the concentrations of HCG ranged between 15 and 405 mUl-2 degrees-IS-hCC/ml. These levels, therefore are higher than the apparent concentrations found in a group of women used as controls who were not pregnant (0 to 4.5 mUl/ml.). In 56 other cycles apparently normal periods followed on the expected date. All the same, the apparent concentration of HCG (2 to 32 mUl/ml) is far higher often than in the control group. The interference of LH in the level makes it impossible to decide between two hypotheses: whether raised levels of LH are associated with irregular menstrual function or with fertilisation, followed by premature expulsion of the oocyte.

Chorionic Gonadotropin↗