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F Vidal

Publications and source records attributed to F Vidal.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Yield of blood cultures in relation to the cultured blood volume in Bactec 6A bottles].

BACKGROUND: Concentration of microorganisms in blood is low in bacteremia from extravascular sources. The best yield from blood cultures is achieved by culturing a minimum of 10-20 ml, although in some processing blood culture systems such as Bactec NR-860, smaller volume is used. The objectives of the present study were to establish the frequency in which inadequate small blood volumes are employed for culturing and to analyze the relation between the cultured blood volume in Bactec 6A bottles and the yield achieved. MATERIAL AND METHODS: We weighed 2000 Bactec 6A bottles pertaining to consecutive blood cultures obtained from untreated patients with clinical suspicion of Infection. The cultured blood volume was estimated subtracting the mean empty bottle weight. RESULTS: Microorganisms were recovered from 251 bottles (12.5%). One hundred and thirty one (6.8%) isolates were considered as clinically significant and 115 (5.7%) as contaminant. The inoculated blood volume in both significant (5.532 +/- 1.587 ml) and non-significant (5.471 +/- 1.563 ml) recoveries was superior than that of bottles without microbiologic growth (5.209 +/- 1.575 ml, p = 0.016 and p = 0.06, respectively). A linear positive trend was found between the cultivated blood volume and the rate of recoveries (p = 0.008). Within the range of 1 up to 10 ml, the rate of recoveries increased 2.28% for each additional ml of cultivated blood (r = 0.953, p < 0.0001). Out of the 2,000 weighed bottles 127 (6.3%) contained less than 3 ml of blood and 576 (29%) between 3 and 5 ml. CONCLUSIONS: We have proved that the rate of recoveries from Bactec 6A bottles increased with the volume of cultured blood. In untreated patients, this increase is maintained up to volumes of 7 to 10 ml.

Adult↗
PubMed1997

Alcohol dehydrogenase of human and rat blood vessels. Role in ethanol metabolism.

Alcohol dehydrogenase (ADH) activity has been detected in all arteries and veins examined from humans and rat. In distinct human autopsy vessels, activity values range from 0.9 +/- 0.2 to 9.9 +/- 7.7 mU/mg. Distribution of the activity in human aorta was: intima (23.5%), media (74%) and adventia (2.5%). In most of the samples the beta1 beta1 isozyme of class I ADH was the only form responsible for the ADH activity. Class IV ADH (sigma sigma-ADH) was present in three of the 28 individuals examined. The rat blood vessels showed class IV, but not class I, ADH localized in endothelium and media. The physiological role of vascular ADH is probably related to retinoid metabolism and elimination of lipid peroxidation aldehydes. A contribution to human ethanol metabolism is supported by the significant amount of low-Km activity and the extension of the vascular system.

Adult↗
PubMed1997

Cryopreservation of caprine beta-lactoglobulin transgenic mouse embryos.

As an economical and safer alternative to the maintenance of transgenic animals as live stocks, transgenic embryo cryobanks can be generated and maintained indefinitely. Two-cell embryos obtained from four lines of caprine beta-lactoglobulin transgenic mice homozygous for the transgene were cryopreserved, and their response to cryopreservation-related stress was investigated. Significant differences between transgenic lines were found in the viability of frozen/thawed transgenic embryos and also in two-cell embryo production after superovulatory treatment of transgenic females. The results of this study suggest that cryopreservation protocols should be assessed on each transgenic line before the generation of transgenic embryo banks.

Animals↗
PubMed1997

Increased incidence of disomic sperm nuclei in a 47,XYY male assessed by fluorescent in situ hybridization (FISH).

Using triple-colour fluorescent in situ hybridization in decondensed sperm heads, we assessed the sex-chromosome distribution in spermatozoa from a 47,XYY male compared with controls. The incidence of spermatozoa with 24,XY (0.30%) and 24,YY (1.01%) disomy was significantly higher than in our control series. Diploid meiocytes present in the ejaculate were mainly 47,XYY (60.6-86.7%), and haploid meiocytes were mainly 24,XY (78.1%).These results suggest that, although the extra Y chromosome is thought to be eliminated during spermatogenesis, XYY germ cells can complete meiosis and produce disomic spermatozoa.

Adult↗
PubMed1997

Chromosome segregation in a man heterozygous for a pericentric inversion, inv(9)(p11q13), analyzed by using sperm karyotyping and two-color fluorescence in situ hybridization on sperm nuclei.

Analysis of sperm karyotypes and two-color fluorescent in situ hybridization (FISH) on sperm nuclei were carried out in a man heterozygous for the pericentric inversion inv(9)(p11q13). Sperm chromosome complements were obtained after in vitro fusion of zona-free hamster oocytes and donor sperm. A total of 314 sperm complements was analyzed: 153 (48.7%) carried the inverted chromosome 9 and 161 (51.3%) carried the normal one. None of the sperm complements contained a recombinant chromosome 9, suggesting that no chiasmata were formed in the heterochromatic region. The frequency of structural chromosome aberrations unrelated to the inversion (8.3%) and the frequency of conservative aneuploidy (3.2%) were within the limits observed in our control donors. The proportions of X-bearing (47.3%) and Y-bearing sperm (52.7%) were not significantly different from the expected 1:1 ratio. The percentage of disomy for chromosome 21 was analyzed by two-color FISH in 10336 sperm nuclei. The disomy rate for chromosome 21 (0.30%) was not significantly different from that found in our controls. These results suggest that the risk for this man of producing chromosomally abnormal offspring or spontaneous abortions was not increased, and do not support the existence of an interchromosomal effect for chromosome 21.

Adult↗
PubMed1997

Mevalonate deprivation impairs IGF-I/insulin signaling in human vascular smooth muscle cells.

3-Hydroxy-3-methylglutaryl Coenzyme A (HMG-CoA) reductase inhibitors (statins) are therapeutically used to lower plasma cholesterol levels. In addition, these drugs can block vascular smooth muscle cell (VSMC) proliferation. The present study addressed the question whether the inhibitory effect of lovastatin on premitotic DNA synthesis correlates with a downregulation of c-fos mRNA levels, a marker of signaling efficiency, in human SMC. Here we show that in human SMC exposed to individual growth factors (platelet-derived growth factor, epidermal growth factor, alpha-thrombin, insulin, insulin-like growth factor I (IGF-I)) and human serum, the maximal [3H]thymidine incorporation and c-fos mRNA expression are closely correlated. Only alpha-thrombin elicited overexpression of c-fos as compared with its effect on [3H]thymidine incorporation. Lovastatin efficiently inhibited [3H]thymidine uptake promoted by all mitogens tested (76-87%); however, it significantly inhibited upregulation of c-fos mRNA levels induced only by insulin (33-67%, P < 0.05) and IGF-I (31 57%, P < 0.05). This inhibition was overcome by mevalonate and geranylgeraniol, and partially by farnesol. c-fos mRNA expression induced by 4-beta-phorbol-12-myristate-13-acetate, an activator of protein kinase C, was insensitive to lovastatin treatment. Thus, in human vascular SMC, lovastatin impairs premitotic DNA synthesis induced by growth factors, but only c-fos expression promoted by insulin and IGF-I. These data indicate that statin-sensitive and -insensitive pathways seem to be involved in the regulation of c-fos in the response of human SMC to proliferative stimuli, and suggest a prominent role of isoprenylated proteins in the activation of VSMC through the IGF-I/insulin dependent pathways.

Cells, Cultured↗
PubMed1997

Expression of caprine beta-lactoglobulin in the milk of transgenic mice.

A 14.5 kb-long transgene containing the complete caprine beta-lactoglobulin gene transcription unit as well as 6.1 kb and 3.7 kb of the 5'- and 3'-flanking regions, respectively, was microinjected into pronuclear stage mouse embryos. Four lines of transgenic mice were obtained, three of them expressing the transgene in their mammary glands during lactation. Western blot analysis of caprine beta-lactoglobulin in the milk of hemizygous transgenic animals demonstrated the presence of the exogenous protein at concentrations up to 0.5 mg ml-1 of mouse milk.

Animals↗
PubMed1997

Origin of tripronucleate zygotes after intracytoplasmic sperm injection.

Zygotes morphologically classified as tripronuclear (3PN) after intracytoplasmic sperm injection (ICSI), which are thought to be digynic in their origin, were studied by fluorescent in-situ hybridization (FISH). FISH results allowed us to assess the suspected ploidy after morphological evaluation of the zygote and to determine the origin of the third pronuclei. Our results show that, firstly, 36% of those zygotes classified as 3PN following their morphological evaluation were, in fact, diploid, and secondly, the main cause for triploidy after ICSI is the non-extrusion of the second polar body.

Cell Nucleus↗
PubMed1997

An epidural abscess due to resistant Staphylococcus aureus following epidural catheterisation.

We report a case of abscess formation after epidural analgesia, a rare complication that developed in our patient 13 days after placement of a thoracic epidural catheter for patient controlled analgesia. Culture of the pus grew methicillin-resistant Staphylococcus aureus. Although early diagnosis and rapid management have been reported to yield a satisfactory outcome, the case we describe ended in severe sequelae.

Abscess↗
PubMed1997

Fatal Listeria meningitis, endocarditis and pericarditis in a patient with haemochromatosis.

A 65-year-old man with primary haemochromatosis was admitted because of fever and confusion. He was found to have bacteraemia and meningitis due to Listeria monocytogenes. Treatment with ampicillin plus tobramycin was instituted, and despite an initial improvement, the patient experienced an unfavourable course and died. At postmortem examination, tricuspid valve endocarditis and purulent pericarditis with tamponade were detected. Listeria monocytogenes grew in the culture of the pericardial fluid. Documentation of Listeria monocytogenes pericarditis is extremely rare, and data on the patient described and on seven published cases are reported.

Aged↗
PubMed1997

Immunological and virological activity of zalcitabine and zidovudine in combination in HIV-positive people with CD4 cell counts of between 200-500 cells/mm3.

We evaluated the effect of combination therapy with zidovudine (AZT) plus zalcitabine (ddC) in human immunodeficiency virus type 1 (HIV-1)-infected patients who had not previously received antiretroviral treatment ('naive' patients). The immunological and virological parameters evaluated were CD4 cell count, syncytium-inducing (SI) viral phenotype and plasma HIV-1 RNA copies/ml (HIV viral load). A total of 75 patients entered the study, with CD4 cell counts between 200 and 500 cells/mm3. All received zidovudine (200 mg) plus zalcitabine (0.75 mg) three times daily for 24 weeks. Treatment was well tolerated. However, four patients presented with anaemia (haemoglobin < 10.0 g/dl) and one patient had both anaemia and neutropenia (0.8 x 10(9) neutrophils/l). Combination therapy with zidovudine plus zalcitabine resulted in a pronounced improvement of virological and immunological markers. Approximately 25% of patients achieved undetectable plasma HIV RNA levels (< 200 copies/ml) at week 24. At the end of the study (24 weeks) a significant reduction (> 0.5 log) of plasma HIV RNA was observed in approximately 70% of patients and in 50% an even greater decrease (> 1 log) was achieved. The most significant decrease in mean plasma HIV RNA levels was observed at week 4, whereas the highest increase in CD4 cell count was found at week 24. Approximately 80% of patients who showed baseline plasma HIV RNA levels below 20000 copies/ml had less than 5000 copies/ml at week 24. The plasma HIV RNA reduction observed at week 4 was significantly maintained at week 24. Therefore, we can rapidly select those who will not respond to therapy and adjust the treatment after a short interval. Our study supports the idea of early therapy because all patients who reached undetectable levels of plasma HIV RNA at week 24 had at baseline a median plasma HIV RNA load of 2560 copies/ml. In conclusion, zidovudine in combination with zalcitabine was well tolerated in the majority of patients and led to a significant reduction in plasma HIV RNA copies in most of the patients with initial viraemia lower than 20000 copies/ml.

Anti-HIV Agents↗
PubMed1997

[Subconjunctival anesthesia: an alternative for vitrectomy in mitochondrial myopathy].

The case of a 63-year-old woman with mitochondrial myopathy with palpebral ptosis and nighttime nasal home oxygen therapy is reported. The patient successfully underwent outpatient vitrectomy with subconjunctival anesthesia, receiving no premedication or sedation during the operation. Subconjunctival analgesia was provided, with prior instillation of an anesthetic collyrium followed by subconjunctival injection of 1 ml of 0.4% bupivacaine and 2% lidocaine. Analgesia during surgery was satisfactory. We review the possibilities of using this technique in patients at high risk of presenting postoperative complications after general anesthesia, and discuss the possible side effects on musculature when peribulbar or retrobulbar anesthesia is provided.

Anesthesia, Local↗
PubMed1996

Epidemiology and outcome of Pseudomonas aeruginosa bacteremia, with special emphasis on the influence of antibiotic treatment. Analysis of 189 episodes.

OBJECTIVE: To evaluate the trend in incidence of Pseudomonas aeruginosa bacteremia, underlying conditions of patients, mortality rate, and factors associated with poor outcome. PATIENTS AND METHODS: Medical charts of 189 consecutive episodes of P aeruginosa bacteremia, detected between January 1, 1991, and December 31, 1994, were prospectively evaluated. Associated risk factors, treatment, and outcome were recorded. RESULTS: Pseudomonas aeruginosa bacteremia represented 5.7% of the total number of bacteremias, 6.9% of nosocomial bacteremias, and 23.6% of nosocomial gram-negative bacteremias. There were 1.5 episodes per 1000 discharges. These numbers were slightly lower than those recorded at our hospital 10 years earlier. Human immunodeficiency virus infection was the most frequent underlying disease (28/189 [15%]). Overall mortality was 18% (34/189). The presence of fatal underlying disease (P < .001), surgery (P = .001), pneumonia (P = .02), and severe sepsis (P < .001) were associated with poor prognosis, the mortality of the patients with these variables being 28%, 28%, 47%, and 62%, respectively. The presence of inappropriate definitive antimicrobial treatment became an independent factor predictive of death (P = .04) only when the subset of patients with intravenous catheter-associated bacteremia was excluded from the analysis. The survival rate was no greater in patients who received 2 or more antibiotics active in vitro against P aeruginosa than in those who received only 1. Neutropenia was not associated with increased mortality. The use of colony-stimulating factors did not affect the outcome of the neutropenic patients. CONCLUSIONS: The rate of P aeruginosa bacteremia is falling slightly at our hospital. The emergence of the human immunodeficiency virus epidemic has had a considerable impact on both epidemiology and mortality. The presence of severe underlying disease, surgery, pneumonia, and, especially, severe sepsis are associated with a poor outcome. With the exclusion of patients with intravenous catheter-associated P aeruginosa bacteremia, the administration of an appropriate antimicrobial therapy is essential to a good outcome. Treatment with 1 active antibiotic seems to be sufficient.

Aged↗