Biomedical subjects

I Fernandez

Publications and source records attributed to I Fernandez.

59 records · Page 4Linked to original sources

PubMedDate not supplied

Fibrolytic activities and cellulolytic bacterial community structure in the solid and liquid phases of rumen contents.

Four sheep were fed an alfalfa hay diet. Rumen content samples were collected three hours after feeding in order to total microorganism population (TP), solid attached population (SAP) and solid attached firmly population (SAFP). Fibrolytic specific activities (xylanase, CMCase and beta-glycosidases) were estimated by the amount of reducing sugars or p-nitrophenol released from the appropriate substrate. The distribution of the three main cellulolytic bacterial species (Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens) was quantified by dot-blot hybridisation using specific 16S-rRNA-targeting probes. Specific activities of polysaccharidase enzymes were higher in SAP than in TP, and in SAFP than in SAP. The sum of RNA of the three cellulolytic bacterial species represented on average 9% of the total bacterial RNA, and increased after filtration. In all samples, the relative population size of F. succinogenes was higher than that of R. albus and of R. flavefaciens. These results demonstrate that the most active enzymes are secreted by the particle-associated microorganisms. The differences in composition of the microflora between the solid and liquid phase suggest that bacteria are not equally distributed throughout the rumen content: the cellulolytic species are present in a higher proportion in the solid phase of rumen contents.

Animals↗

PubMedDate not supplied

Reproducibility of optic nerve head measurements obtained by optical coherence tomography.

PURPOSE: To evaluate reproducibility of optic nerve head (ONH) morphometry measurements obtained by optical coherence tomography (the fast optical disk protocol of the -Zeiss model 3000 OCT system) in normal and glaucomatous eyes. METHODS: Prospective instrument-evaluation study. ONH measurements for 20 eyes were obtained in eight scan sessions taken during two visits to an ophthalmology clinic (10 normal patients, 10 glaucoma patients, one eye per subject). At every one of the eight sessions for each eye, estimates of eight ONH morphometry variables (see Main outcome measures) were obtained. The first two sessions were performed by two operators, followed by a 30-minute break. The same operators then completed a third and fourth session. This sequence was duplicated on a second visit. Intrasession, intersession, intervisit, and interoperator reproducibility of the eight variables were calculated by the use of a components variance model. Intraclass correlation coefficients (ICC) were used to assess reliability. RESULTS: Vertical integrated rim area, horizontal integrated rim area, disk area, cup area, rim area, cup/disk area ratio, cup/disk horizontal ratio, cup/disk vertical ratio. With the exception of the horizontal integrated rim area and rim area in normal subjects, the factor subject was the most important source of variance for all variables. Reliability values as measured by ICC for normal eyes were above 81%, with the exception of measurements of the horizontal integrated rim area (23.1%), rim area (33.3%), and disk area (64.7%). For glaucomatous eyes all values were above 85%, with the exception of the disk area (68.1%). CONCLUSIONS: ONH measurements obtained using the fast optical disk protocol of the Zeiss 3000 OCT system show good reproducibility, for both normal and glaucomatous eyes.

Adult↗

PubMedDate not supplied

Prediction of the lower esophageal sphincter pressure after oral molsidomine by sydnonimine plasma concentrations.

BACKGROUND/AIMS: Recent studies suggest that endogenous nitric oxide decreases lower esophageal sphincter pressure (LESP). Substances leading to the formation of nitric oxide, such as molsidomine, decreases the human LESP. It is not yet clear whether this reduction is related to plasma concentrations of molsidomine, the nitrate-active substance sydnonimine (SIN-1) or to serum concentrations of nitrate/nitrite (NOx) as a stable end-product of volatile nitric oxide. METHODOLOGY: We performed a double blind controlled crossover trial in 8 healthy male volunteers. Plasma concentrations of molsidomine, SIN-1 and serum concentrations of NOx as well as esophageal manometry were determined. RESULTS: Mean basal LESP was significantly decreased from 25.4 +/- 2.8 mmHg to 21.9 +/- 2.7 mmHg and 21.4 +/- 2.6 mmHg 2 and 3 hours after molsidomine administration, respectively (mean +/- SEM; n = 8; p < 0.05). The maximum decrease of LESP from the baseline within 1-4 hours after molsidomine administration was 7.6 +/- 1.5 mmHg (mean +/- SEM; n = 8; p < 0.01). The decrease of the LESP correlated significantly with plasma concentrations of SIN-1 (r = -0.53; p = 0.002). NOx levels remained unchanged. CONCLUSIONS: Molsidomine decreases the LESP and plasma concentrations of the active metabolite SIN-1 may predict the potency of molsidomine to lower LESP. NOx was useless as a control metabolite to measure the LESP in response to molsidomine in healthy volunteers.

Administration, Oral↗

PubMedDate not supplied

[Absence of HTLV-I/II virus circulation in blood donors from the provinces of Santa Fe and Santiago del Estero].

In the present study, we evaluated the seroprevalence of HTLV-I/II infection among the blood donors in Santa Fe and Santiago del Estero provinces. A total of 1327 serum samples from blood donors from Rafaela blood bank of Santa Fe province and 3382 serum samples from blood donors from Dr Edgar Bouzon blood bank of Santiago del Estero province were studied. The antibody screening was done by particle agglutination assay (PA) (SERODIA, Fujirebio Inc., Tokyo, Japan) or by enzyme immuno assay (EIA) (Abbott HTLV-I/HTLV-II EIA, Abbott, Germany). The "in house" indirect immunofluorescence assay (IFA) and Western blot (Bioblot HTLV Biokit, Barcelona, Spain) were used as confirmatory assays. All the samples resulted negative for specific antibodies against HTLV-I/II. These results suggest that HTLV-I/II are not circulating in low risk populations in these provinces or that the prevalences of infection would be lower than that reported by blood banks in other provinces of Argentina.

Adult↗

PubMedDate not supplied

Clinical effects of fluvoxamine on panic symptomatology.

In a double-blind randomized placebo-controlled cross-over design trial, the effects of a 4 week fluvoxamine versus a 4 week placebo treatment regimen on panic symptomatology were studied. Fluvoxamine seems to have specific antipanic properties, as a significant decrease in the number of panic attacks was observed. Other components of the disorder, like free-floating anxiety and avoidance behavior were not influenced during the short 4 week treatment period.

Adult↗