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Biomedical subjects

M F Fernández

Publications and source records attributed to M F Fernández.

14 recordsLinked to original sources
PubMed2003

Probiotic properties of human lactobacilli strains to be used in the gastrointestinal tract.

AIMS: The study of two human strains of Lactobacillus to be used as probiotics in the gastrointestinal tract. METHODS AND RESULTS: The Lactobacillus acidophilus UO 001 and Lact. gasseri UO 002, were resistant to the gastrointestinal conditions (pH 2 and 3, presence of pepsin, pancreatin or bile salts), the resistance was enhanced in the presence of skimmed milk. Additionally, adhered to Caco-2 cells through glycoproteins in Lact. gasseri and carbohydrates in the case of Lact. acidophilus. These strains are able to inhibit the growth of certain enteropathogens: Salmonella, Listeria and Campylobacter without interfering with the normal microbiota of the gastrointestinal tract, as stated by using the mixed culture and the spot agar test. Finally, strongly adherent Lact. gasseri were found to inhibit the attachment of Escherichia coli O111 to intestinal Caco-2 cells under the condition of exclusion. CONCLUSIONS: These results indicate that the two strains of Lactobacillus from human origin present important properties for survival in, and colonization of, the gastrointestinal tract, that give them potential probiotic. SIGNIFICANCE AND IMPACT OF THE STUDY: Two strains of Lactobacillus isolated from human vagina of healthy premenopausal women could be promising candidates to be used in the preparation of probiotic products and for their use as health-promoting bacteria.

Adhesins, Bacterial↗
PubMed2002

The effect of AH 26 and AH Plus on MCF-7 breast cancer cell proliferation in vitro.

AIM: The purpose of this study was to determine whether AH 26 and AH Plus have in vitro oestrogenic effects. METHODOLOGY: MCF-7 breast cancer cells were trypsinized and plated in 24-well plates at initial concentrations of 10,000 cells per well in 5% FBS in DME. Cells were allowed to attach for 24 h; then the seeding medium was replaced with 10% CDHuS-supplemented phenol red-free DME. Different concentrations of the test compound were added to sample wells (AH 26 and AH Plus at 1/100 to 1/1,000,000 dilutions), 10 pM estradiol-17beta to positive controL and no sub-stance to negative control (hormone-free control cells). The assay was stopped after 144 h. RESULTS: AH 26-powder induced MCF-7 cell proliferation in a dose-dependent manner. The cell yield obtained with AH 26-powder at 1/100 dilution sample was 2.5-fold greater than in control cultures. The sam-ple prepared with mixed AH 26 paste/powder 1:1 also induced MCF-7 cell proliferation, but showed less potency than AH 26-powder alone. The cell yield obtained with AH 26 paste/powder at 1/100 dilution sample was 1.9-fold greater than in control cultures. AH Plus did not show in vitro oestrogenic effect. CONCLUSIONS: AH 26 showed in vitro oestrogenic effect, but not AH Plus. The endodontist must consider the possible oestrogenic effect of AH 26, as well as the cytotoxic effects of root filling materials, and avoid the leakage of sealer through the apex during root canal treatment.

Benzhydryl Compounds↗
PubMed2000

Complications after total laryngectomy in nonradiated laryngeal and hypopharyngeal carcinomas.

To study the complications of total laryngectomy, we evaluated 471 previously untreated patients who underwent total laryngectomy between 1980 and 1997. This series consisted of 358 patients with primary carcinoma of the larynx and 113 with carcinoma of the hypopharynx. Concurrent neck dissection was performed in 85% of patients. Complications were studied in relation to age, T and N stage, previous tracheostomy, neck dissection, margins, reconstruction, tracheoesophageal puncture, and surgeon. Complication treatment and hospitalization were also evaluated. The overall complication rate was 30.7%, with 29.2% major and 6.5% minor complications. The mortality rate was 0.6% (3/471). Pharyngocutaneous fistula was the most frequent wound complication (21%), followed by wound infection (4.2%) and hemorrhage (2.3%). Pneumonia (1.4%) and embolism (0.4%) were the most frequent medical complications. Hypopharyngeal tumors, neck dissection, and extended procedures had a significantly higher rate of complications. Complication causes, prevention, and treatment are discussed.

Adult↗
PubMed1999

Antibodies to a synthetic 1-9-N-terminal amino acid fragment of mature pediocin PA-1: sensitivity and specificity for pediocin PA-1 and cross-reactivity against Class IIa bacteriocins.

Polyclonal antibodies specific for pediocin PA-1 (PedA1) were generated by immunization of rabbits with a chemically synthesized 1-9-N-terminal amino acid fragment of this bacteriocin (PH1) conjugated to the carrier protein keyhole limpet haemocyanin (KLH). The PH1 fragment holds a highly conserved amino acid sequence with closely related Class IIa bacteriocins. The sensitivity and specificity of the PH1-KLH-generated rabbit polyclonal antibodies were evaluated by the development of various ELISAs, such as a non-competitive indirect ELISA (NCI-ELISA), a competitive indirect ELISA (CI-ELISA), a competitive direct ELISA (CD-ELISA) and a sandwich ELISA (S-ELISA), and by protein slot-blotting and Western blotting. NCI- and CI-ELISA were valuable for detecting the existence of PedA1-specific antibodies in the sera of immunized rabbits. The limit of detection of PedA1 in MRS medium was found to be 0.5 microg ml(-1) in NCI-ELISA, while CI-ELISA on plates coated with purified PedA1 increased the affinity of the PH1-KLH-generated antibodies for PedA1; the limit of detection of PedA1 was less than 0.01 microg ml(-1) and 50% binding inhibition was achieved with 0.1 microg PedA1 ml(-1). Similarly, the limits of detection of PedA1 in MRS medium were found to be 5 microg ml(-1) by protein slot-blotting and 0.01 microg ml(-1) by Western blotting. Most importantly, PH1-KLH-generated polyclonal antibodies detected the presence of PedA1 in the supernatants of the producing strains of Pediococcus acidilactici 347, Z102, A172, X13 and P20, with no reactivity or negligible immunoreactivity with the supernatants of other lactic acid bacteria producing or not producing closely related or different bacteriocins. The approaches taken for the selection of the bacteriocin peptide fragment, the generation of antibodies and the development of immunoassays could prove useful for the generation and evaluation of antibodies of adequate specificity for other bacteriocins of interest in the food industry.

Amino Acid Sequence↗
PubMed1999

[Lower limb monoplegia and dissociated hypoesthesia after peridural anesthesia].

Neurological sequelae reported after epidural anesthesia include epidural hematoma, spinal cord ischemic injury and lumbosacral nerve root injury. We describe here a case of monoplegia of the right lower limb associated with an ipsilateral loss of perception of pain and temperature following an epidural anesthesia. MRI was compatible with a right centrolateral infarction in the gray matter of the spinal cord below D8. Hypotension, vascular spasm, trauma, arteriosclerosis, pressure increase in the epidural space are potential causative mechanisms. Unilateral symptoms might result from injury to a sulcocommissural artery or an anterior spinal artery when duplicated.

Aged↗
PubMed1998

Analgesic, antiinflammatory, and antipyretic effects of S(+)-ketoprofen in vivo.

Many studies indicate that the S-enantiomers of arylpropionic (APA) nonsteroidal antiinflammatory drugs (NSAIDs) are the pharmacologically active enantiomers. S(+)-ketoprofen (dexketoprofen) stereoselectively inhibits cyclooxygenase (COX) in vitro but very little is known about the differential activity of ketoprofen enantiomers in vivo. We examined the analgesic, antiinflammatory, and antipyretic activities of S(+)-ketoprofen in rats and mice. First, we measured the antinociceptive action of S(+)-ketoprofen in abdominal pain models. After intravenous administration. 0.5 mg/kg S(+)-ketoprofen inhibited 92.1+/-2.2% of writhing in mice. Stereoselectivity in the activity was detected; intravenous administration of the R(-)-enantiomer resulted in no statistically significant activity in a dose range of 0.15-1 mg/kg. Similar results were obtained after oral administration in mice. In the rat, S(+)-ketoprofen was a more potent analgesic than diclofenac by both intravenous and oral administration. There was no significant difference between the analgesic effect of S(+)-ketoprofen treatment and the twofold dose of the racemic form in both the mouse and rat models. Second, we measured the antiinflammatory activity of S(+)-ketoprofen using a carrageenan-induced paw edema model in the rat. Intravenous administration of 5 mg/kg of S(+)-ketoprofen almost completely inhibited edema formation. After oral administration, S(+)-ketoprofen is both more potent and effective than diclofenac. Third, we measured antipyretic activity. S(+)-ketoprofen showed a marked antipyretic action (ED50 = 1.6 mg/kg) and was the most potent of the NSAIDs tested. S(+)-ketoprofen is a potent antiinflammatory, analgesic, and antipyretic agent in vivo, consistent with its potent anti-COX activity.

Administration, Oral↗
PubMed1997

Lactic acid bacteria: hydrophobicity and strength of attachment to meat surfaces.

The hydrophobicity and strength of attachment of several lactic acid bacteria with antimicrobial activity were studied. Hydrophobicity was determined by bacterial adherence to hydrocarbons (BATH; octane or xylene), adhesion to nitrocellulose filters (NCF), salt aggregation test (SAT) and adherence to phenyl-Sepharose beads (PSB). The relative hydrophobicity of lactic acid bacteria depended markedly on the method used. No correlation between either SAT or BATH (octane) and strength of attachment (Sr value) existed. However, a significant relationship between strength of attachment and BATH (xylene), NCF and PSB, respectively, was observed, showing the highest correlation coefficient (r = 0.778) for BATH (xylene).

Ammonium Sulfate↗
PubMed1997

The problem of diagnosing von Willebrand's disease.

Diagnosis of von Willebrand's disease (vWD), particularly vWD Type 1, remains a clinical problem for several aspects. Its definitive diagnosis requires documentation of three factors: bleeding, low levels of qualitatively normal von Willebrand factor (vWF), and inheritance. In the absence of any of these factors the diagnosis may be only merely 'possible', or even unacceptable. Laboratory diagnosis of vWD includes screening tests and confirmatory tests. vWD Types 2 and 3 are relatively easy to diagnose and appear to be genetic disease of a single locus, the vWF gene. As new genetic and possibly non-genetic factors are discovered, the diagnosis of vWD Type 1 may become easier.

Diagnosis, Differential↗
PubMed1996

Attachment of lactic acid bacteria to beef-muscle surfaces.

The effect of immersion time and cell concentration in the attachment of several lactic acid bacteria with antibacterial activity to beef-muscle surface was studied. The number of firmly attached bacteria increased with immersion time in the case of Pediococcus acidilacti, Lactobacillus sake, Lactococcus cremoris (two strains) and Pediococcus acidilacti. Pediococcus pentosaceus, Lactococcus lactis and Lactobacillus curvatus reached maximum adhesion after 15-30 min. The highest strength of attachment (Sr values) were observed after 15-30 min of contact time except for P. pentosaceus. For all strains, the number of bacteria adhering to meat increased with increasing cell concentration in the adhesion medium. The highest strength of attachment was observed at a cell concentration of 10(5)/mL mainly for L. sake, L. lactis and L. cremoris. Due to their attachment characteristics, L. sake, L. lactis and L. cremoris are proposed as potential biocontrol agents because they could grow on meat surface and limit the potential attachment of pathogenic microorganisms.

Animals↗
PubMed1993

[Utilization of lactic bacteria in the control of pathogenic microorganisms in food].

The lactic acid bacteria have the potential to inhibit the growth of pathogenic and spoilage bacteria and the possibility exists of using them to improve the hygienic quality and to extend the shelf-life of different foods. Among the many inhibitory substances produced by the lactic acid bacteria, the bacteriocins are of particular interest. It has been the objective of this work to review the bacteriocins produced by lactic acid bacteria from the genera Lactococcus, Lactobacillus and Pediococcus, as well as Leuconostoc and Carnobacterium to understand their relevant biochemical, immunological and genetic characteristics. The lactic acid bacteria may also express foreign genes codifying metabolites with antimicrobial activities against foodborne pathogens of interest, and this will also permit hypothesize about theoretical and experimental models of microbial antagonism mediated by the lactic acid bacteria.

Bacteriocins↗
PubMed1992

Sakacin M, a bacteriocin-like substance from Lactobacillus sake 148.

The antagonistic activity of Lactobacillus sake 148 was evaluated during its growth on complex broth media and in a semisynthetic defined medium (SDM) with various supplements. The antagonistic activity was a growth-associated property, being detected and quantified when L. sake 148 was grown at either 4, 8, 16, 25 or 32 degrees C. The concentrated culture supernatant of L. sake 148 was subjected to purification by lyophilization and gel filtration. The purification procedure resulted in a small increase in its specific activity (7-fold) and in a low recovery of the original inhibitory activity (8%). Gel filtration analysis of the partially purified activity on Sephadex G-50 revealed an apparent molecular weight of 4640. The partially purified antagonistic activity of L. sake 148 was destroyed by treatment with proteolytic enzymes. However, the antagonistic activity was resistant to heat, having D-values at 121, 135 and 150 degrees C of 23.8, 17.4 and 15.2 min, respectively.

Animals↗
PubMed1991

Antibacterial activity of Lactobacillus sake isolated from dry fermented sausages.

Lactic acid bacteria isolated from Spanish dry fermented sausages were screened for antagonistic activities under conditions that eliminated the effects of low pH and hydrogen peroxide. From 720 isolates tested 119 were inhibitory to Lactobacillus fermentum CECT285. The isolates showing the largest inhibitory activity exhibited an antagonistic effect against several other lactobacilli and the selected foodborne pathogens Staphylococcus aureus and Listeria monocytogenes. Comparison of the antimicrobial spectra of the supernatants suggested that the inhibitory compounds were not identical. The isolates were tentatively characterized as Lactobacillus sake. One of the isolates, L. sake 148 was chosen for further study. The compound excreted by L. sake 148 was active against various lactobacilli and several Gram-positive foodborne bacteria, but not against the Gram-negative bacteria tested. The antagonistic effects were almost eliminated by treatment with proteases, whereas they were heat resistant and bacteriostatic rather than bacteriocidal.

Animals↗
PubMedDate not supplied

[Perspectives on endocrine disruption].

Two decades ago, reports of alterations in the reproductive function of some wild animal species and clear evidence of human and animal exposure to chemical substances with hormonal activity agonist and antagonist generated what is known now as the hypothesis of endocrine disruption. This is an emerging environmental health problem that has challenged some of the paradigms on which the control and regulation of the use of chemical compounds is based. The need to include in routine toxicology tests new research objectives that specifically refer to the development and growth of species and to the homeostasis and functionality of hormonal systems, has served to complicate both the evaluation of new compounds and the re-evaluation of existing ones. The repercussions on regulation and international trade have not taken long to be felt. On both sides of the Atlantic, screening systems for endocrine disrupters have been designed and established, and research programmes have been launched to characterise and quantify adverse effects on human and animal health and to develop preventive measures.

Animals↗