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Biomedical subjects

F Vicente

Publications and source records attributed to F Vicente.

At least 37 records · Page 2Linked to original sources
PubMed2001

Urinary energy losses in dogs fed commercial extruded foods.

Energy and nitrogen losses in the urine were recorded in 134 individual balances with adult (1- to 2-year-old) female Beagles that were fed 23 dry extruded dog foods ranging in crude protein (CP) content from 242 to 360 g/kg dry matter. The energy equivalent of urinary nitrogen was estimated as 33.9 kJ/g N. Both energy losses in the urine corrected for the nitrogen balance, and the metabolizable energy (MEn): digestible energy (DE) ratio were found to be closely related to diet CP content (r : 0.851 and 0.820). The MEn content of extruded dog foods can be accurately calculated from the DE content, either by subtracting 4.59 MJ/kg CP or estimating the MEn/DE ratio from the food CP content by the following equation: MEn/DE=0.98 - 3.44 +/- 0.517 x CP (kg/MJ DE).

Animal Feed↗
PubMed2001

The effect of crude fibre on apparent digestibility and digestible energy content of extruded dog foods.

The apparent digestibility of nutrients and energy of 38 commercial dry extruded dog foods was measured using six adult (2 to 3 year-old) female Beagles. Diets contained [in g/kg dry matter (DM)]: 164-360 crude protein (CP); 79-261 ether extracts (EE); 8-33 crude fibre (CF) and 318-585 nitrogen free extracts (NFE). Apparent energy digestibility ranged from 77.3 to 91.6%, and was closely related to CF content (r=-0.85), yielding the resultant equation: GED (%)=94.00 - 4.04 x CF (% DM). The estimation of digestible energy content of foods from digestibility coefficients predicted from the above equation and gross energy measured or estimated from the Weende fractions, provides a more accurate prediction of experimental values than the Atwater approach followed by the National Research Council and the Association of American Feed Control Officials.

Animal Feed↗
PubMed2000

The discovery of enfumafungin, a novel antifungal compound produced by an endophytic Hormonema species biological activity and taxonomy of the producing organisms.

In a screening of natural products with antifungal activity derived from endophytic fungi, we detected a potent activity in a culture belonging to the form-genus Hormonema, isolated from leaves of Juniperus communis. The compound is a new triterpene glycoside, showing an antifungal activity highly potent in vitro against Candida and Aspergillus and with moderate efficacy in an in vivo mouse model of disseminated candidiasis. The agent is especially interesting since its antifungal spectrum and its effect on morphology of Aspergillus fumigatus is comparable to that of the glucan synthase inhibitor pneumocandin B,,, the natural precursor of the clinical candidate MK-0991 (caspofungin acetate). An additional search for other Hormonema isolates producing improved titers or derivatives resulted in the isolation of two more strains recovered from the same plant host showing identical activity. The producing isolates were compared with other non-producing Hormonema strains by DNA fingerprinting and sequencing of the rDNA internal transcribed spacers. Comparison of rDNA sequences with other fungal species suggests that the producing fungus could be an undetermined Kabatina species. Kabatina is a coelomycetous genus whose members are known to produce Hormonema-like states in culture.

Animals↗
PubMed2000

Discovery of novel antifungal (1,3)-beta-D-glucan synthase inhibitors.

The increasing incidence of life-threatening fungal infections has driven the search for new, broad-spectrum fungicidal agents that can be used for treatment and prophylaxis in immunocompromised patients. Natural-product inhibitors of cell wall (1,3)-beta-D-glucan synthase such as lipopeptide pneumocandins and echinocandins as well as the glycolipid papulacandins have been evaluated as potential therapeutics for the last two decades. As a result, MK-0991 (caspofungin acetate; Cancidas), a semisynthetic analogue of pneumocandin B(o), is being developed as a broad-spectrum parenteral agent for the treatment of aspergillosis and candidiasis. This and other lipopeptide antifungal agents have limited oral bioavailability. Thus, we have sought new chemical structures with the mode of action of lipopeptide antifungal agents but with the potential for oral absorption. Results of natural-product screening by a series of newly developed methods has led to the identification of four acidic terpenoid (1,3)-beta-D-glucan synthase inhibitors. Of the four compounds, the in vitro antifungal activity of one, enfumafungin, is comparable to that of L-733560, a close analogue of MK-0991. Like the lipopeptides, enfumafungin specifically inhibits glucan synthesis in whole cells and in (1,3)-beta-D-glucan synthase assays, alters the morphologies of yeasts and molds, and produces a unique response in Saccharomyces cerevisiae strains with point mutations in FKS1, the gene which encodes the large subunit of glucan synthase.

Antifungal Agents↗
PubMed1999

Study of the solid-phase extraction of diclofenac sodium, indomethacin and phenylbutazone for their analysis in human urine by liquid chromatography.

A selective semi-automated solid-phase extraction (SPE) of the non-steroidal anti-inflammatory drugs diclofenac sodium, indomethacin and phenylbutazone from urine prior to high-performance liquid chromatography was investigated. The drugs were recovered from urine buffered at pH 5.0 using C18 Bond-Elut cartridges as solid sorbent material and mixtures of methanol-aqueous buffer or acetonitrile-aqueous buffer as washing and elution solvents. The extracts were chromatographed on a reversed-phase ODS column using 10 mM acetate buffer (pH 4.0)-acetonitrile (58:42, v/v) as the mobile phase, and the effluent from the column was monitored at 210 nm with ultraviolet detection. Absolute recoveries of the anti-inflammatory drugs within the range 0.02-1.0 microg/ml were about 85% for diclofenac and indomethacin, and 50% for phenylbutazone without any interference from endogenous compounds of the urine. The within-day and between-day repeatabilities were in all cases less than 5% and 10%, respectively. Limits of detection were 0.007 microg/ml for diclofenac sodium and indomethacin and 0.035 microg/ml for phenylbutazone, whereas limits of quantitation were 0.02 microg/ml for diclofenac and indomethacin and 0.1 microg/ml for phenylbutazone.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Semi-automated solid-phase extraction procedure for the high-performance liquid chromatographic determination of alinastine in biological fluids.

A solid-phase extraction (SPE) method for sample clean-up followed by a reversed-phase HPLC procedure for the assay of alinastina (pINN) in biological fluids is reported. The effects of the sample pH, composition of the washing and elution solvents and the nature of the SPE cartridge on recovery were evaluated. The selectivity of SPE was examined using spiked rat urine and plasma samples and the CH and PH cartridges gave rise to the cleanest extracts. The recoveries obtained in spiked rat urine and plasma samples were 91.2+/-2.7 and 99.9+/-2.8%, respectively. The proposed SPE method coupled off-line with a reserved-phase HPLC system with fluorimetric detection was applied to the quantitation of alinastine in real rat urine samples. The analytical method was also applied and validated for the determination of alinastine in dog plasma. The recovery from spiked dog plasma samples using the PH cartridge was around 65%. The within-day and between-day precisions were 7 and 12%, respectively. The detection and quantitation limits in dog plasma were 0.024 and 0.078 microg/ml, respectively.

Animals↗
PubMed1997

Antimicrobial activity of viridiofungins.

A family of aminoacyl alkyl citrate compounds called viridiofungins, are novel squalene synthase inhibitors. The compounds have broad spectrum fungicidal activity but lack antibacterial activity. Although the compounds inhibit squalene synthase, the first committed step in ergosterol biosynthesis, results presented in this paper show that inhibition of fungal growth is not related to inhibition of ergosterol synthesis.

Antifungal Agents↗
PubMed1996

Pseudoaneurysm of the inferior epigastric artery. Pathogenesis, diagnosis, and treatment.

We present a new case of pseudoaneurysm of the abdominal wall, subsidiary to the inferior epigastric artery, associated with the use of discharge sutures. Pseudoaneurysms are a well-known complication of surgery, puncture, or trauma. Pseudoaneurysms of the inferior epigastric artery are very infrequent. We know of only two cases in the literature. In both cases, the pseudoaneurysm was associated with the use of discharge sutures. We discuss its pathogenesis, diagnosis, and treatment.

Adult↗
PubMed1993

Analysis of oxazepam in urine using solid-phase extraction and high-performance liquid chromatography with fluorescence detection by post-column derivatization.

A reversed-phase high-performance liquid chromatographic method for oxazepam in human urine samples has been developed. The sample preparation consists of an enzymatic hydrolysis with beta-glucuronidase, followed by a solid-phase extraction process using Bond-Elut C2 cartridges. The mobile phase used was a methanol-water (60:40, v/v) mixture at a flow-rate of 0.50 ml/min. The column was a 3.5 cm x 4.6 mm I.D. C18 reversed-phase column. The detection system was based on a fluorescence post-column derivatization of oxazepam in mixtures of methanol and acetic acid. A linear range from 0.01 to 1 micrograms/ml of urine and a limit of detection of 4 ng/ml of urine were attained. Within-day recoveries and reproducibilities from urine samples spiked with 0.2 and 0.02 microgram/ml oxazepam were 97.9 and 95.0 and 2.1 and 9.4%, respectively.

Chromatography, High Pressure Liquid↗
PubMed1993

Voltammetric behavior of berenil.

Berenil is reduced on mercury drops electrode in buffered aqueous media. The reduction of -N=N- group is controlled by diffusion. Polarographic waves are of analytical usefulness. The hydrogen discharge is favored by the basic centers of the molecule in Co(II)/ammonia-buffered media.

Diminazene↗
PubMed1983

Paraffin embedded "Echinococcus granulosus" protoscoleces as suitable antigen in the indirect immunofluorescence test for human hydatid disease.

The employment of Echinococcus granulosus protoscoleces embedded in paraffin as antigen for the indirect immunofluorescence (IIF) test for human hydatid disease is described. An evaluation of its sensitivity and specificity is made studying 108 pre-operative sera from surgically confirmed hydatidosis and 91 control sera. Using the positivity criterion based on the serological reactivity at which minimum cross-reactivity was observed, the IIF test showed an overall sensitivity of 83.3% and 2.2% of cross-reactions. No differences in sensitivity between sera from hepatic and pulmonary hydatidosis was observed. The advantages of the method are pointed out.

Cross Reactions↗