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P Rodríguez

Publications and source records attributed to P Rodríguez.

86 records · Page 5Linked to original sources
PubMedDate not supplied

Contrasting physiological responses of dwarf sea-lavender and marguerite to simulated sea aerosol deposition.

Plants of two wild native species from littoral areas, marguerite [Argyranthemum coronopifolium (Willd.) C.J. Humphries] and dwarf sea-lavender [Limonium pectinatum (Aiton) O. Kuntze], grown in an unheated plastic greenhouse, were sprayed 2 to 3 min per day over a 7-d period with different aqueous solutions containing (i) an anionic surfactant (S1); (ii) a solution simulating the composition of sea aerosol (S2); (iii) a solution simulating sea aerosol with anionic surfactant (S3), and (iv) deionized water alone (control). The plant resistance to sea aerosol and the ability to recover from treatments were studied. By the end of the spraying period, marguerite showed a significant reduction in growth compared with control. However, most of the growth parameters were significantly unaffected in dwarf sea-lavender when plants were treated with sea aerosol containing surfactant. Measurements of water relations variables in marguerite showed a slight decrease in leaf turgor potential after spraying with sea aerosol containing surfactant. The surfactant enhanced the foliar absorption of salt in marguerite plants, inducing reductions in leaf stomatal conductance and causing such damage in the photosynthetic apparatus that the level of net photosynthesis decreased and had not recovered by the end of the experiment. The treatments had no effect on leaf stomatal conductance and photosynthesis rate in dwarf sea-lavender plants. The response of the species studied to sea aerosol was related to the degree of salinity tolerance. Although both species are wild native plants from littoral areas, marguerite is not salt tolerant and was the most sensitive to the sea aerosol treatments, while dwarf sea-lavender, a halophyte species, was more efficient at decreasing the toxic salt content of the tissues as its growth and ornamental characteristics were not affected.

Absorption↗
PubMedDate not supplied

Differences in the effects of simulated sea aerosol on water relations, salt content, and leaf ultrastructure of rock-rose plants.

White-leaf rock-rose (Cistus albidus L.) and Montpellier rock-rose (C. monspeliensis L.) plants were sprayed 2 to 3 min per day over a 7-d period, in an unheated plastic greenhouse, with different aqueous solutions containing deionized water alone (control); an anionic surfactant (sodium dodecylbenzenesulfonate 82.5%, 50 mg L(-1)) (S1); a solution simulating the composition of sea aerosol (S2); and a solution simulating sea aerosol with anionic surfactant (S3). White-leaf rock-rose was more sensitive to sea aerosol, showing greater leaf damage and markedly decreased growth, and the presence of surfactant enhanced the phytotoxic effect leading to greater increases in mortality. Montpellier rock-rose did not appear to be more adversely affected when surfactant was used in combination with sea aerosol, and manifested slight or less severe symptoms than white-leaf rock-rose. There was a significant increase in leaf turgor potential in the plants treated with both sea aerosol treatments by osmotic adjustment effect. The decrease in photosynthesis level seems to be due to both stomatal and nonstomatal factors. The results of microscopical analysis of Montpellier rock-rose plants show that sea aerosol treatment caused alterations in the chloroplast structure, reducing the starch grain and swelling the thylakoid membranes. The results of this study indicated that Montpellier rock-rose was more tolerant to sea aerosol than white-leaf rock-rose, showing a lower reduction in plant growth and less leaf damage, probably because of its ability to compartmentalize the toxic ions at the intracellular level.

Aerosols↗
PubMedDate not supplied

Clinical, histologic and genetic characterization of non-Hodgkin's lymphomas in Mexicans.

We describe the anatomical distribution, histological and molecular characteristics of 32 cases of NHL. Staging of the NHL was made according to conventionally accepted schemes. Histologically the NHL were classified in grades following the criteria defined by the Working Formulation. Rearrangements in one or more Ig or TcR receptor genes were detected in Southern blots and allowed us to determine the cell type and stage of differentiation. Serological analysis of 26 serum samples revealed the existence of antibodies against EBV epitopes; eight of these patients carried viral sequences in the tumor genome as determined by slot blot hybridization. Our studies indicate that the use of various methods is of paramount importance in order to improve our understanding of the natural history of NHL.

Adolescent↗
PubMedDate not supplied

[Hepatinecrosis caused by furosemide. Special lesions of various species?].

Furosemide is a wellknown hepatotoxic agent in rodents. Toxicity is result of the production of a catabolite by action of microsomal enzymes. The goal of this study was to demonstrate differences in toxicity between two rodents species: rat and hamster. Animals received 400 mg/k/i.p. of furosemide, with or without pretreatment with phenobarbital as enzymatic inducer. Adequates controls were used. Microscopic findings were different in both groups. Rats treated with furosemide plus phenobarbital, exhibited extensive mediozonal necrosis; when those without pretreatment, showed less extensive necrosis of liver cells, erratic in distribution. In contrast, it was a lack of necrosis in hamsters' livers, showing only unremarkable changes.

Animals↗
PubMedDate not supplied

[Etiology of enteritis in a university general hospital in Barcelona (1992-1995)].

BACKGROUND: The aim of the study was to describe the etiology of enteropathogenic agents over a four-year period (1992-1995) in a University Hospital in Barcelona. METHODS: We studied 12,793 stool samples, 4519 were obtained from patients under 15 years and 8274 were obtained from patients over 14 years. The specimens were examined for bacteriological, parasitological and virological enteropathogens. RESULTS: In 3380 specimens of 12,793 stool samples studied were identified an enteropathogen (26.4%). Polymicrobial associations were observed in the 6.8% of the cases. Pathogens were identified in 45% of children samples and 16.3% of adults samples. The etiological enteritis agents more frequently detected in the paediatric patients were Campylobacter (13.5%), rotavirus (11.3%) and Salmonella (10.2%); and Salmonella (4.9%), Campylobacter (3.1%) and Giardia intestinalis (2.1%) in adults. Cryptosporidium (13.5%) was the most frequent cause of gastrointestinal tract infections in HIV-infected subjects. In the children with stools positives, the presence of red and white blood cells were more frequent than the adults with stools positives (73% versus 26.6%). CONCLUSIONS: The enteropathogenic agents such as Campylobacter, Salmonella, and Giardia were the most frequent cause of gastroenteritis in our environment. In the children, rotavirus infections predominated during the cold months. The most frequent cause of gastroenteritis in HIV-infected patients was Cryptosporidium followed by Campylobacter.

Adolescent↗