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P Ramos

Publications and source records attributed to P Ramos.

97 records · Page 6Linked to original sources
PubMedDate not supplied

[Fragmentation of the lactose-protease plasmid in lactose-negative derivatives of Streptococcus lactis and S. lactis ssp. diacetylactis].

DNA analysis showed the presence of plasmids in all 29 strains of mesophilic lactic streptococci. Their number ranged from 1 to 9 and their molecular weight extended from 1.8 to 45 megadaltons (Md). Comparison of the plasmid profiles from 9 strains of Streptococcus lactis, 3 strains of S. lactis ssp. diacetylactis and from their Lac-,Prt-variants was carried out. In most of the strains, a single plasmid of 27 to 45 Md carried both the lactose and protease (lac and prt) determinants. In Lac- variants, this composite plasmid may at times be lost; in most derivatives, this plasmid was fragmented into several smaller plasmids. Fragmentation resulted in the inactivation of lac genes and often of prt genes; sometimes prt genes remained intact in one of these new plasmids. Fragmentation of the plasmid may also take place without inactivation of these metabolic genes. Restriction analysis of the lactose-protease plasmid from 3 strains of S. lactis and from one Lac-variant confirmed the plasmid fragmentation phenomenon, and led to a proposal for physical mapping of the plasmid and preliminary localization of the lac-prt genes.

DNA Restriction Enzymes↗
PubMedDate not supplied

RT-PCR comparative study of viral load levels in the HIV positive population in Puerto Rico before and after protease inhibitor regimen implanted.

Ponce School of Medicine AIDS Research Program conducted a large scale viral load assessment of Puerto Ricans who are infected by human immunodeficiency virus type 1 (HIV-1) during the summer of 1996 through the Roche ACCESS program before general implementation of combination therapy. Since January 1997, it has monitored those HIV-1 patients who are under treatments at most HIV-1 health care clinics, including both public and private. The present study was conducted to evaluate how the new treatment has generally impacted on the HIV-1 disease status of HIV-1 infected population in the eight Immunology Clinics. Assessment was made by consecutively monitoring the changes in HIV-1 viral load profiles of the population from January to September, 1997. A large majority of samples were delivered for viral load assessment without information of their treatment status, and only a small number of samples were identifiable either as baseline or followup. Despite the paucity of individual information, remarkable improvements of HIV-1 (+) population at large were evident. For example, in the summer of 1996 (ACCESS), population median viral load was 51,842; only 9% of the population had viral load less than 500 viral RNA copies/ml plasma and 72% had over 10,000 copies/ml. By July-September, 1997, the population median dropped to 8,679 (83%); 23% were below 500 copies/ml (+156%) and the proportion of patients who had over 10,000 copies/ml was reduced to 48% (-33%). The group of individuals who were positively identified as "follow-up" (i.e., under active treatment) had a median of 37128 copies/ml (-94%); 28% were below 500 copies/ml (+211%) and only 40% had more than 10,000 copies/ml (-44%). It is obvious that the implementation of triple combination therapy by PASET in 1997, has very markedly improve the HIV-1 disease status of HIV-1 (+) population in Puerto Rico.

HIV Infections↗