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Biomedical subjects

F Almazan

Publications and source records attributed to F Almazan.

7 recordsLinked to original sources
PubMed2001

Coronavirus derived expression systems.

Both helper dependent expression systems, based on two components, and single genomes constructed by targeted recombination, or by using infectious cDNA clones, have been developed. The sequences that regulate transcription have been characterized mainly using helper dependent expression systems and it will now be possible to validate them using single genomes. The genome of coronaviruses has been engineered by modification of the infectious cDNA leading to an efficient (>20 microg ml(-1)) and stable (>20 passages) expression of the foreign gene. The possibility of engineering the tissue and species tropism to target expression to different organs and animal species, including humans, increases the potential of coronaviruses as vectors. Thus, coronaviruses are promising virus vectors for vaccine development and, possibly, for gene therapy.

Coronavirus↗
PubMed2001

Complete genome sequence of transmissible gastroenteritis coronavirus PUR46-MAD clone and evolution of the purdue virus cluster.

The complete sequence (28580 nt) of the PUR46-MAD clone of the Purdue cluster of transmissible gastroenteritis coronavirus (TGEV) has been determined and compared with members of this cluster and other coronaviruses. The computing distances among their S gene sequences resulted in the grouping of these coronaviruses into four clusters, one of them exclusively formed by the Purdue viruses. Three new potential sequence motifs with homology to the alpha-subunit of the polymerase-associated nucleocapsid phosphoprotein of rinderpest virus, the Bowman-Birk type of proteinase inhibitors, and the metallothionein superfamily of cysteine rich chelating proteins have been identified. Comparison of the TGEV polymerase sequence with that of other RNA viruses revealed high sequence homology with the A-E domains of the palm subdomain of nucleic acid polymerases.

Amino Acid Sequence↗
PubMed1997

A new approach to determining the rates of recruitment of circulating leukocytes into tissues: application to the measurement of leukocyte recruitment into atherosclerotic lesions.

Recruitment of circulating monocytes into the artery wall is an important feature of early atherogenesis. In vitro studies have identified a number of adhesion molecules and chemokines that may control this process but very little work has been done to evaluate their relative importance in vivo, in part because there have been no methods available of sufficient sensitivity and reliability. This paper proposes a new approach in which advantage is taken of naturally occurring or transgenically induced mutations to "mark" donor cells and to follow their fate in recipient animals using highly sensitive PCR methods. The feasibility of the approach is demonstrated by preliminary studies of monocyte recruitment into atherosclerotic lesions. However, the method should in principle be applicable to the study of any of the circulating leukocytes and their rate of entry into any tissue or tissues of interest.

Animals↗
PubMed1991

Feasibility of using an oleate-rich diet to reduce the susceptibility of low-density lipoprotein to oxidative modification in humans.

Oxidized low-density lipoprotein (LDL) is more atherogenic than native LDL. The initial step in the oxidation is the peroxidation of polyunsaturated fatty acids. Thus, decreasing the concentration of polyunsaturated fatty acids should reduce the susceptibility of LDL to oxidation. Therefore, we tested the possibility that diets enriched in oleate might result in LDL that is less susceptible to oxidative modification. LDL isolated from subjects consuming an oleate-enriched diet, compared with LDL from subjects on a linoleate-enriched diet, contained significantly more oleate (28.7% vs 11.5%) and less linoleate (31.9% vs 50.9%). Generation of conjugated dienes was significantly lower in the LDL from the oleate group. Most important, after incubation with endothelial cells, LDL from the oleate group underwent less degradation by macrophages. These studies demonstrate the feasibility of altering the diet in a way that will not raise LDL cholesterol concentrations and yet will decrease the susceptibility of LDL to oxidative modification.

Adult↗