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Biomedical subjects

V Acosta

Publications and source records attributed to V Acosta.

6 recordsLinked to original sources
PubMed2000

[Density, growth and survival of Lyropecten (Nodipecten) nodosus (Pteroida: Pectinidae) juveniles in suspended-frame culture in Golfo de Cariaco, Venezuela].

The effect of culture density on growth and survival of juveniles was studied in the scallop Lyropecten nodosus with intermediate hanging cultures in Golfo de Cariaco, Sucre state, Venezuela, from December 1993 to July 1994. Six spat-densities (7, 15, 30, 60, 125 and 250 scallops/nets) were evaluated. The initial shell height and dry mass tissue were 9.4 +/- 0.18 mm and 0.007 +/- 0.0026 g, respectively. The specimens were placed into pearl nets and suspended in a long line at 8 m depth. Growth patterns of somatic tissue were similar, but with different magnitudes and inverse proportionality to culture density. No effect of density was observed on survival. These results suggest that intraspecific competition of cultivated scallops cause stress, which affects growth but not survival. We suggest as strategy for the management of culture density, successive density reductions, to obtain in a six months culture (intermediate culture) specimens of 50 mm in shell height in order to start the final culture period.

Animals↗
PubMed1998

Centrifugal pulsing increases the recovery of viable spermatozoa.

PURPOSE: Our purpose was to compare the number and quality of spermatozoa recover following the standard centrifugation method with those after pulsing the relative centrifugal field during centrifugation. METHODS: A prospectively controlled in vitro study using ejaculates from 10 healthy sperm donors was undertaken. Number of sperm and sperm motility at 0, 3, and 24 hr post-incubation at 5 degrees C in TEST-yolk results determined the efficacy of the centrifugation techniques. RESULTS: The number of sperm and sperm motility at 0, 3, and 24 hr post-incubation at 5 degrees C in TEST-yolk were significantly higher for the sperm recovered following pulse centrifugation compared with those after standard centrifugation. CONCLUSIONS: Pulsing the relative centrifugal field during centrifugation yields a higher number of viable spermatozoa.

Adult↗
PubMed1994

[HIV and blood donors: past, present and future].

PURPOSE: To evaluate the changes in the spectrum of HIV-positive blood donors along seven years. PATIENTS AND METHODS: The municipal Blood Bank of Caracas Federal District examined 193,796 blood donors between 1986 and 1992. Anti-HIV antibodies were determined by the following methods: Ortho HIV-Elisa Test System (59.5% of the samples), Abbott Recombinant HIV-EIA (28.6%), Vironostika HIV Microelisa System-Organon Teknika (2.1%), Bio-Test anti-HIV Recombinant Elisa (2.1%), and Recombigen (env and gag) HIV Cambridge Biotech (7.7%). Results confirmation was performed with Biotech/Dupont HIV-I Western Blot Kit, Chiron Riba HIV 216 Test System and Inno-Lia HIV 1/2 Ab immunogenetics SA. RESULTS: Slow but progressive increase of positive results was seen in the blood donors along the years, from 0.05% in 1986 to 0.31% in 1992. Higher prevalence was seen in males (p < 0.001), although absolute increase in the number of positive females was found by 1992 (p < 0.05). According to their type, 80.6% of the donors were patient-related (RD), 13% attended mobile blood-drawing units (MU) and 6.4% were VD (p < 0.001), with a trend to increase amongst DR and decrease amongst MV. The majority of the positive donors pertained to homo-or bisexuals (60.5%), although they showed progressive decrease, whereas the positive findings increased in the promiscuous heterosexual group and amongst those having contacts with persons at risk. CONCLUSIONS: High prevalence of HIV-positive donors is found, the expected figure for 1995 being 0.37% if the present trends are maintained. Thus, a better selection of blood donors is recommended by means of careful enquiries, the use of optimal reagents capable of shortening the window period, deferring people at risk from blood donation, and promoting altruistic voluntary donation of blood.

Adolescent↗
PubMed1991

[Post-transfusional hepatitis. Preliminary study].

In Venezuela post-transfusional hepatitis (PTH) data is unknown. We studied, prospectively, 147 patients who received blood transfusions (1 to 48 different blood components). They were screened for HBsAg (Ortho HBsAg Elisa Test System), anti HBc (Ortho HBc Elisa Test System and CORZYME, Abbott Laboratories) and amino-transferases (Doles), before and after transfusions. Only the last 36 patients were tested for anti HCV (Ortho HCV antibody Elisa Test)R from the beginning. The test were performed at 2, 7, 12 and 24 weeks subsequently in the negative recipients. PTH for type B virus was 3.8% (5/131), and for NANBH 2.7% (3/110). In both groups those recipients who had more transfusions had the greatest incidence of PTH. We conclude that anti HBc and ALT must be done in all blood donors to prevent the occurrence of PTH either B virus or NANBH. We suggest also, to include anti HCV screening in blood donors as a mean to make blood transfusion safer.

Adolescent↗