Biomedical subjects

M Valverde

Publications and source records attributed to M Valverde.

22 records · Page 2Linked to original sources

PubMed1996

Reprotoxic and genotoxic studies of vanadium pentoxide in male mice.

Effects of vanadium pentoxide (V2O5) treatment on reproductive function and testicular DNA in male mice were investigated. These functions were evaluated with fertility rate, implants, resorptions, sperm counts, motility, and morphology. The DNA damage in individual testis cells was analyzed by single-cell gel electrophoresis technique (COMET assay). V2O5 treatment resulted in a decrease in fertility rate, implantations, live fetuses, and fetal weight, and an increase in the number of resorptions/dam. Sperm count, motility, and morphology were impaired with the advancement of treatment. Vanadium treatment induced DNA damage depending on the dose in the testis cells that was expressed and detected as DNA migration in the COMET assay. The distribution of DNA migration among cells, a function of dose, revealed that the majority of cells of treated animals expressed more DNA damage than cells from control animals. It is concluded that vanadium pentoxide was a reprotoxic and genotoxic agent in mice.

Animals↗

PubMed1993

Sporocidal properties of peracetic acid and hydrogen peroxide, alone and in combination, in comparison with chlorine and formaldehyde for ultrafiltration membrane disinfection.

The sporocidal properties of peracetic acid, hydrogen peroxide, chlorine, and formaldehyde were compared in vitro using a dilution-neutralization micromethod. A combination of peracetic acid and hydrogen peroxide was also tested to assess their interactions. The activities of these agents, which are widely used as disinfectants, were evaluated against Bacillus spore isolates found on stored membranes and collection cultures. Peracetic acid and chlorine exhibited an excellent antimicrobial activity, with a destruction of 10(5) spores/mL after 5 min of contact. Generally the effects of the biocides tested were time dependent. The sporocidal activities of hydrogen peroxide and formaldehyde were the lowest. The combination of peracetic acid and hydrogen peroxide, tested by a checkerboard micromethod, was found to be synergistic. The minimal sporocidal concentration (MSC) was established in terms of time for each biocide. The lowest MSC values for peracetic acid, hydrogen peroxide, chlorine, and formaldehyde were 168-336 ppm (1-2 h of contact), 5625-11250 ppm (5-7 h), 168-336 ppm (2-3 h), and 1875-3750 ppm (5-30 min), respectively. The MSC of a biocide combination of peracetic acid and hydrogen peroxide showed that synergy was maintained with increasing contact time and that the MSC could be reduced by two to eight times when compared with those of the biocides alone. Optimal concentrations and contact times of those chemicals that were promising in vitro were then tested for their ability to disinfect ultrafiltration membranes. The sporocidal activities of peroxide compounds and chlorine were confirmed and the synergism between peracetic acid and hydrogen peroxide was also maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacillus↗

PubMed1993

[Subcutaneous venous reservoirs: comparative study of their efficacy in patients with AIDS versus oncology and hematology patients].

BACKGROUND: Chronic venous access may constitute a serious problem in some patients and the subcutaneous venous reservoirs have demonstrated to be a useful alternative. AIDS patients require intense pharmacologic treatment, thus the use of subcutaneous venous reservoirs may be specially useful. However, the prevalence of septic type complications following placement of the subcutaneous venous reservoirs in these patients is particularly high. AIMS: To know the efficacy of subcutaneous venous reservoirs in the AIDS population and compare the results in a non AIDS population. METHODS: All the subcutaneous venous reservoirs placed between January 1990 and December 1992 were prospectively studied with two groups being established: Group I: patients with positive serology for HIV and who achieved criteria of AIDS requiring placement of a subcutaneous venous reservoirs. Group II: All the remaining patients in whom a subcutaneous venous reservoirs was placed during the same period of time. RESULTS: The incidence of infection was higher in group I (AIDS) with respect to group II (0.1 versus 0.014 infections/100 catheters/day, p < 0.01) and the non septic complications were higher in group II (3.6% versus 12.7%, p < 0.0004). The catheters were most frequently used in group I with respect to group II (12.7 +/- 7.1 versus 3.3 +/- 4.9 punctures/month) but the period was use longer in group II (13.7 +/- 9.2 versus 4.3 +/- 3.1 months, p < 0.0001). CONCLUSIONS: The population of AIDS patients may benefit greatly from the systematic use of subcutaneous venous reservoir due to their clinical and therapeutic characteristics. Nonetheless greater risk of infection may occur in these patients because of the greater need for punctures with respect to the other indications for placement of these catheters.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Dermatophytoses in Cusco (Peru).

A total of 90 cases of suspected dermatophytoses was observed over a period of 9 months in the city of Cusco (Peru) and in its environs. The age groups most commonly infected were 1-10 and 11-20 year old. The most common tineae diagnosed were tinea capitis (13.3%) and tinea unguium (11.1%). Only four species of dermatophytes were isolated: Microsporum canis (52.4%), Trichophyton mentagrophytes (35.7%), Tr. rubrum (9.5%) and Epidermophyton floccosum (2.4%). Dry weather, low temperature and high altitude do not seem to affect proliferation and infections by dermatophytes.

Adolescent↗