Search PubMed⌕ Search

Biomedical subjects

F Lamy

Publications and source records attributed to F Lamy.

At least 91 records · Page 5Linked to original sources
PubMed1977

Photolysis of desmosine and isodesmosine by ultraviolet light.

It is known that the pyridinium ring of a model compound such as N-methyl pyridinium chloride is cleaved by U.V. radiation at 254 nm. At acid pH the products obtained are methylamine and glutaconaldehyde. Under the same conditions desmosine and isodesmosine are degraded into lysine and probably into the homologous substituted ketone of glutaconaldehyde. At pH 6.0-7.0, a transient open-chain aminoaldehyde intermediate is observed which can either reform the original compound or be cleaved as at low pH. When intact elastin is photolysed for 20 minutes in water, approximately 75% of the (iso) desmosines are destroyed, accompanied by an increase of free lysine residues. No change in the concentration of the other amino acids, including tyrosine, are noted. It is therefore likely that the crosslinks engaged in peptide links are also cleaved photochemically.

Amino Acids↗
PubMed1976

UDP-glucose dehydrogenase from Escherichia coli. Purification and subunit structure.

UDPglucose dehydrogenase from Escherichia coli has been purified 330-fold with an overall yield of 27%. A single homogeneous subunit was demonstrated by ultracentrifugation in 6 M guanidium chloride and by dodecyl sulfate-polyacrylamide gel electrophoresis. Since the molecular weight of the intact dehydrogenase is in the order of 86 000 and the subunit weight determined by the dodecyl sulfate-polyacrylamide gel electrophoresis is 47 000, the enzyme consists of two polypeptide chains. The sole amino terminal acid shown by the dansylation technique was arginine. Forty-four tryptic peptides were obtained by peptide mapping, in agreement with the number of arginine and lysine residues/mole protein [43] determined by amino acid analysis. The data are consistent with the presence of two identical or very similar polypeptide chains in E. coli UDPglucose dehydrogenase.

Alcohol Oxidoreductases↗
PubMed1976

Photolysis of desmosine and isodesmosine by ultraviolet light.

1. Desmosine and isodesmosine were separated by ion-exchange and paper chromatography, after acid hydrolysis of purified elastin from beef ligamentum nuchae. The fractions obtained by ion-exchange chromatography were clearly mixtures of related compounds. The desmosine fraction could be resolved into seven compounds and the isodesmosine into four by paper chromatography. 2. Desmosine was maximally degraded by irradiation at 274 nm and isodesmosine at 285 nm. These wavelengths did not correspond to the absorption maxima of the cross links, but to shoulders of the main absorption peaks. 3. When irradiated at their optimum wavelengths, but at various pH, both desmosine and isodesmosine seemed quite stable at pH greater than 8.5. Between pH 8 and 5, the photolytic rate was maximum and decreased slightly at more acidic pH. Below pH 4.0, one of the products of photolysis was free lysine. 4. In analogy to the mechanism of the photolytic degradation of N-methyl pyridinium chloride, it appears that the (iso)desmosines were degraded via the formation of an open amino aldehyde, which was hydrolysed at acid pH to give free lysine and a substituted glutaconic aldehyde.

Amino Acids↗
PubMed1975

Electrophoretic characterization of porcine pancreatic (pro)elastases A and B.

Two porcine pancreatic zymogens can be separated by free electrophoresis on a sucrose gradient. After activation by trypsin, both enzymes can hydrolyze completely the fibrous protein elastin. One of the two proteins, proelastase B, has, in addition, an esterolytic activity towards N-acetyl-L-tyrosine ethyl ester. The other, proelastase A, does not possess it. The activation products of the zymogens have been tagged with radioactive diisopropylfluro-phosphonate and separated by polacrylamide-gel electrophoresis. Proelastase A gives only one active species, pancreatopeptidase E, but three distinct proteins can be obtained from proelastase B. Elastases A and B exhibit an important synergism when acting together upon a purified elastin lacking microfibrils. Trypsin has considerably less synergistic activity, and chymotrypsin has practically none.

Animals↗
PubMed1975

Purification and characterization of a trypsin inhibitor from Solanum tuberosum.

A trypsin inhibitor isolated from a potato acetone powder has been purified by affinity chromatography. This protein inhibits trypsin mole per mole. To a lesser extent it combines also with chymotrypsin and elastase. For trypsin, K1 = 8 X 10(-7) M. The inhibitor has a single polypeptide chain of 207 amino acid residues. It contains no sugar or free sulfhydryl groups. Its extinction coefficient E2801% = 10.3 and its isoelectric point is 6.9. Its molecular weight is of the order of 21 000-22000, as determined by sedimentation equilbrium, by inhibition experiment or from its amino acid composition. These same techniques, taken together with the single band observed at different pH on polyacrylamide gel electrophoresis, indicate that the protein purified is monodisperse. However, the finding of two N-terminal amino acid residues, leucine and aspartic acid, and the different stoichometry observed during the interaction of the inhibitor, either with trypsin or with chymotrypsin and elastase, raises the possibility that our preparation is contaminated by a polyvalent inhibitor not detectable by physiochemical methods.

Amino Acids↗
PubMed1975

Live attenuated influenza virus vaccines in patients with chronic broncho-pulmonary diseases. Clinical and immunological evaluation.

The safety and potency of two live attenuated influenza A virus vaccines, administered intranasally, were tested in outpatients suffering from chronic obstructive lung disease, during two successive trials performed between 1972 and 1974. The vaccine strains were representative of the prevalent influenza A virus types; the Ann strain was derived from a classical H3N2 (A/Hong-Kong/878/69) isolated and the Alice strain from a recent H3N2 drift (A/England/42/72). The serum and nasal antibody responses were studied in a total of 40 vaccinees. When a sufficient virus dose was administered, the hemagglutination-inhibition (HI) seroconversion rate was, respectively, 86 and 73% for each vaccine trial in patients with low (less than or equal to 32) prevaccination antibody titers. A booster effect was also observed in some subjects with higher prevaccination titers. In the two trials, clear-cut rises in local antibody activity, as tested in nasal washings' samples were found in, respectively, 92 and 75% of the patients devoid of initial titer before vaccination and in 40 and 37%, respectively, of the subjects having low prevaccination titers. Clinical symptoms were observed in 29% of the cases; they were, however, mild and transient and their occurrence was not necessarily related to the vaccination. Two administrations of intranasal attenuated virus appear therefore to be safe and to lead to a satisfactory antibody response in this "high risk" group of patients.

Adult↗
PubMed1975

Immune response to combined live influenza virus vaccines administered intranasally.

The immune responses in volunteers vaccinated intranasally with a live influenza virus vaccine containing attenuated A and B strains have been studied. The hemagglutination-inhibiting antibody titers for both components were determined a few weeks after vaccination. They demonstrated that a good antibody response had been induced in a high percentage of volunteers. The hemagglutination inhibiting titers and percentage of seroconversion for both components were comparable to the results obtained after the intranasal administration of each component separately.

Administration, Intranasal↗
PubMed1973

Immune response to vaccination with a live influenza virus (H3N2) vaccine ("Ann" strain).

A live attenuated influenza virus ("Ann" strain) derived from A/England/878/69 was given intranasally to a group of volunteers, most of whom had already circulating antibodies against H(3)N(2) viruses at the time of inoculation. There was a fourfold or higher increase of circulating hemagglutination-inhibiting antibodies in those volunteers who had relatively low initial titers. The response was lower in those with initially higher serum titers. The pattern of the serum neutralizing antibody response was very similar. The geometric means of the antineuraminidase antibodies were 67 and 118 pre- and postvaccination, respectively. All subjects showed a rise in local neutralizing antibodies in their nasal secretions with geometric means of 4 and 17 pre- and postvaccination, respectively. The levels of local antineuraminidase antibodies also rose in most subjects. In addition to the response to the homologous virus type, the antibody formation to the recent A/England/42/72 was measured in the sera and nasal secretions of some subjects. There was a clearcut response in most of the sera and in all of the secretions examined. The stimulation of circulating lymphocytes was measured in 6 volunteers. All volunteers showed a temporary stimulation. The stimulation index ranged between 2.5 and 28.5.

Administration, Intranasal↗