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M Legrain

Publications and source records attributed to M Legrain.

At least 19 recordsLinked to original sources
PubMed1992

Two-dimensional 1H NMR study of recombinant insect defensin A in water: resonance assignments, secondary structure and global folding.

A 500 MHz 2D 1H NMR study of recombinant insect defensin A is reported. This defense protein of 40 residues contains 3 disulfide bridges, is positively charged and exhibits antibacterial properties. 2D NMR maps of recombinant defensin A were fully assigned and secondary structure elements were localized. The set of NOE connectivities, 3JNH-alpha H coupling constants as well as 1H/2H exchange rates and delta delta/delta T temperature coefficients of NH protons strongly support the existence of an alpha-helix (residues 14-24) and of an antiparallel beta-sheet (residues 27-40). Models of the backbone folding were generated by using the DISMAN program and energy refined by using the AMBER program. This was done on the basis of: (i) 133 selected NOEs, (ii) 21 dihedral restraints from 3JNH-alpha H coupling constants, (iii) 12 hydrogen bonds mostly deduced from 1H/2H exchange rates or temperature coefficients, in addition to 9 initial disulfide bridge covalent constraints. The two secondary structure elements and the two bends connecting them involve approximately 70% of the total number of residues, which impose some stability in the C-terminal part of the molecule. The remaining N-terminal fragment forms a less well defined loop. This spatial organization, in which a beta-sheet is linked to an alpha-helix by two disulfide bridges and to a large loop by a third disulfide bridge, is rather similar to that found in scorpion charybdotoxin and seems to be partly present in several invertebrate toxins.

Amino Acid Sequence↗
PubMed1990

Negative regulatory elements of the Saccharomyces cerevisiae PHO system: interaction between PHO80 and PHO85 proteins.

The negative regulatory genes, PHO80 and PHO85, involved in transcriptional regulation of the yeast repressible acid-phosphatase-encoding gene, PHO5, have been cloned. Expression of PHO80 and PHO85 has been studied by means of lacZ fusions. We show here that these expressions are inorganic phosphate (Pi) independent and that they are controlled by the PHO80 gene product; moreover, PHO80 expression is controlled by PHO85. We also present genetic evidence for an interaction between the PHO80 and PHO85 proteins: increased PHO85 gene dosage partially compensates for the pho80-1 mutation and this effect is allele-specific. The pho80-1 allele has been cloned and sequenced. The mutation changes Gly229 to Asp. This region was shown to be essential for PHO80 function by C-terminal deletion analysis.

Acid Phosphatase↗
PubMed1989

High yield synthesis of the bovine leukemia virus (BLV) p24 major internal protein in Saccharomyces cerevisiae.

Bovine leukemia virus (BLV) p24 gene was expressed in Saccharomyces cerevisiae under the control of the PHO5 (encoding repressible acid phosphatase, rAPase) promoter. Yeast cells were transformed by a yeast-E. coli shuttle vector carrying the PHO5 promoter, the p24 gene and the CYC1 transcription terminator. After low inorganic phosphate (Pi) induction of the PHO5 promoter, p24 accumulated in the producing cells up to a concentration representing 10% of total soluble proteins. The expression level of p24 gene was not increased by insertion of the positive regulatory gene PHO4 on the p24 expression vector. The p24 produced in this system and incubated in crude yeast extract showed a remarkably high resistance to proteolytic degradation, a feature that presumably correlates with the compact globular conformation of the protein combined to the stabilizing effect of the N-terminal residue.

Acid Phosphatase↗
PubMed1989

Biochemical and immunological characterization of the bovine leukemia virus (BLV) envelope glycoprotein (gp51) produced in Saccharomyces cerevisiae.

The nucleotide sequence coding for bovine leukemia virus (BLV) envelope glycoprotein gp51 was inserted into a yeast-Escherichia coli shuttle vector carrying the promoter and secretion signal sequence of PHO5 (the yeast gene coding for repressible acid phosphatase) and the CYC1 transcriptional terminator. Yeast cells transformed by this construction synthesized gp51 after PHO5 induction by inorganic phosphate deprivation. The yeast-expressed gp51 was partially glycosylated into heterodisperse protein molecules ranging from 40 to 48 kDa. No gp51 was excreted in the culture medium. The amount of protein accumulated in yeast cells was estimated to reach 0.06% of soluble proteins. This modest level of expression seemed to be due to the toxicity of gp51 to the yeast cell. The yeast-expressed gp51 products were used in enzyme-linked immunosorbent assays for the detection of antibodies in sera from BLV-infected animals; they were also screened for the presence of well-defined biological epitopes. In both studies poor reactivity was observed. Rabbits immunized with the recombinant gp51 showed high antibody titers to native BLV gp51. However, these antibodies did not neutralize BLV in vitro.

Acid Phosphatase↗
PubMed1979

[Glomerulonephritis: critical evaluation of immunological tests performed routinely (author's transl)].

The clinical value of the immunological tests performed routinely has been evaluated in 91 patients with various histological types of glomerulonephritis. An antigen possibly involved in the pathogeny of renal disease was found in 24% cases. However, in most instances no direct link between the presence of this given antigen and the disease could be observed. Therefore systematic investigations for antigens should be restricted to dosages of antistreptolysin and antinuclear antibodies and to determination of Hbs antigen. Immune complexes, which were observed in many cases, were of no discriminant value for the clinician. Dosages of the complement fractions and the determination of cryoglobulins can be helpful for diagnostic, follow-up and treatment. Our results justify a restricted selection of the routine immunological tests used in patients with glomerulonephritis. More specific investigations remain useful when they are clinically oriented.

Antibodies, Antinuclear↗
PubMed1979

[Society of Nephrology, Computer Technology Commission. Dialysis computer program. VI. - Survival and risk factors].

The sixth report of the "Diaphane Dialyse Informatique" Program concerns 2,518 adult patients (age 15 and over) treated by chronic hemodialysis or hemofiltration in 33 French dialysis centres between June 1972 and December 1978. 1) The number of centers participating to the program is progressively increasing. Overall duration of follow-up represents 4,192 patient-years, allowing precise evolutive studies of terminal renal failure treated by hemodialysis. 2) Mean age at start of treatment continues to increase. Among 709 patients who started treatment in 1977-1978, 8,8 p. 100 of men and 11 p. 100 of women were over 69 years old. 3) Patients with diabetic nephropathy represent 4,4 p. 100 of all patients dialyzed between 1972 and 1978 and 5,9 p. 100 of the patients starting treatment in 1977-1978. 4) The percentage of patients temporarily treated by peritoneal dialysis before hemodialysis decreases from 32,9 p. 100 in 1973-1974 to 15,9 p. 100 in 1977-1978. 5) In 1978, 65,3 p. 100 of patients are dialyzed 3 times a week with a mean weekly duration of 14,0 h for male and 12,9 for female. 73 p. 100 of the patients are dialyzed during the night. 6) Disposable parallel plate hemodialyzers (71,8 per cent of dialysis sessions in 1978) and hollow fiber hemodialyzers (11,6 per cent) progressively replace disposable coil dialyzers and non disposable Kiil dialyzers. 7) Transient hypotensive episodes during dialysis sessions remain the most frequent complications (21,7 per cent of sessions in 1978). Transient hypotensive episodes are more frequently observed with coils than with parallel plate hemodialyzers or with hollow fiber dialyzers. 8) Mean diastolic blood pressure (DBP) +/- SD is 101,9 +/- 21,7 mmHg at start of dialysis and 81,4 +/- 11,8 mmHg when dialysed. During the course of treatment 28,7 per cent of the patients receive long term antihypertensive treatment. In spite of dialysis and antihypertensive treatments 11 per cent of all patients followed up maintain DBP greater than or equal to 95 mmHg. 9) Viral hepatitis remain the most prominent infectious problem with 30 per cent of patients being chronic Hbs antigen carriers. 10) Annual death rate calculated in the 2,518 patients dialyzed between 1972 and 1978 (78/1000) is 12 times superior to the death rate of the French population, adjusted for sex and age to the dialysis population. 43,1 per cent of deaths are of cardiovascular origin. Risk factors for overall mortality are age, sex (male), existence of a vascular or diabetic nephropathy, twice weekly dialysis strategy, elevation of systolic or diastolic blood pressure during the course of dialysis treatment, hypocholesterolemia and to a lesser extent hypotriglyceridemia. On the contrary, hypercholesterolemia, hypertriglyceridemia and hyperuricemia do not appear as risk factors for overall mortality or cardiovascular mortality. These results plead for a perfect control of hypertension and to the extension of thrice weekly dialysis for the whole population of patients treated by maintenance hemodialysis.

Adolescent↗
PubMed1978

[The prognosis in primary chronic glomerulonephritis in the adult. 298 clinicopathological cases (author's transl)].

The study involved 298 cases of chronic glomerulonephritis (GN) in adults. The results of renal biopsy were used to classify the patients into four groups: Membranous GN, 81 cases; focal glomerulo sclerosis, 80 cases; Membrano-proliferative GN, 62 cases; GN with mesangial deposits of IgA, 75 cases. The patients were observed over a period ranging from 1 month to 36 years. The average period of surveillance for each category was between 4 and 6 years. The course in each histological type was assessed on the basis of actuarial tates of renal death, of moderate renal insufficiency (plasma creatinine greater than 1.5 mg%( and of hypertension. Renal survival at 10 years was was arounds 90% for membranous GN. 85% for GN with mesangial deposits of IgA, 70% for focal glomerulo sclerosis and 50% for membrano-proliferative GN. The prognosis should be based upon a combination of histological and clinical findings. Severity of prolonged nephrotic syndrome, regardless of the histological type of the nephropathy, is worthy of emphasis. In the group fo focal glomerulo sclerosis, prognosis differs greatly in relation to the presence or absence of a nephrotic syndrome. Complete remission may be seen in the group of focal glomerulo sclerosis, and in membrano-proliferative GN despite the persistence or worsening of histological lesions seen on repeated biopsies.

Adult↗
PubMed1978

[Effect on serum aluminium levels of continued ingestion of aluminium gels by patients with chronic renal insufficiency (author's transl)].

Atomic spectrometric absorption without flame allows reliable determination of serum aluminium levels (S.A.). Serum level in 59 normal subjects taking no aluminium gel (A.G.) is 24.3 +/- 8.4 microgram/l. Similar value were observed in 27 patients with renal insufficiency even severe who do not take A.G. Mild elevation of S.A. (40 +/- 12 microgram/l) was observed in 21 dialysed patients receiving no A.G. S.A. elevation is related to the aluminium content of dialysis fluid. A.G. intake in patients with renal insufficiency is followed by increase of S.A. The levels increase in relation with the daily dose of A.G. The highest values are observed among dialysed patients. In 41 dialysed cases A.S. values are between 70 and 600 microgram/l. In 17 patients dialysed for a mean period of 47 months mean serum A.S. is 165 +/- 40 microgram/l. The precise role of aluminium intoxication in the genesis of the dialysis encephalopathy syndrom remains controversial. From a clinical point of view aluminium intoxication should be looked for in any patient with encephalopathy who is taking aluminium gels and/or who is dialysed.

Aluminum↗
PubMed1978

Focal glomerulosclerosis: natural history and treatment. A report of 70 cases.

70 cases of focal glomerulosclerosis (FGS) followed for periods ranging from 1 to 24 years are reported. 39 patients had a nephrotic syndrome. 31 patients had asymptomatic proteinuria. 97 renal biopsies were performed. At least one biopsy specimen from every patient showed focal and segmental involvement of glomeruli, but no lesions were observed on the first biopsy in 6 patients. 26 of the 35 patients with a nephrotic syndrome were treated with steroids alone and/or chemotherapy and/or indomethacin. Resistance to treatment was encountered in 21 patients. Complete remission was observed in 6 cases, despite persistence or accentuation of histological lesions on serial biopsies in 3 cases. Actuarial renal survival rate at 10 years was 45% in the group with a nephrotic syndrome versus 91% in patients with proteinuria. FGS with a persistent nephrotic syndrome represents the 'malignant' form of the disease. Recurrence of the disease was observed after transplantation in 2 cases and was absent in 1.

Adolescent↗
PubMed1978

Clinical significance of circulating immune complexes detection in chronic glomerulonephritis.

Sera from 168 patients with various types of chronic glomerulonephritis (GN) were assayed for immune complexes (IC) by two independent methods, a modification of the PEG precipitation test (PEG) and the inhibition of complement-dependent lymphocyte rosette formation (RI). Both assays had different reactivities, the RI being more sensitive than the PEG test. Higher percentages of positivity of these tests were observed in the GN groups than in normal controls. However serial measurements demonstrated that IC were present only intermittently in most instances. The presence of IC correlated with disease activity in patients with focal glomerulosclerosis membranous GN and membranoproliferative GN, while in lupus erythematosus it reflected the effects of different treatment regimens although it had no relationship with clinical symptoms. Nevertheless, our results suggest that these tests are of little help to the clinician to appreciate disease activity and monitor therapy in individual GN patients.

Antigen-Antibody Complex↗