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Biomedical subjects

F J González

Publications and source records attributed to F J González.

At least 19 recordsLinked to original sources
PubMed2006

Cloning and characterization of the erg1 gene of Trichoderma harzianum: effect of the erg1 silencing on ergosterol biosynthesis and resistance to terbinafine.

Trichoderma species are commonly used as biocontrol agents of different plant-pathogenic fungi. Terpene compounds are involved in the biocontrol process due to their antifungal properties (e.g., ergokonins and viridins) but additionally their structural function in the cell membranes (ergosterol) is essential. We report here the characterization of the T. harzianum erg1 gene, encoding a squalene epoxidase, a key enzyme in the biosynthesis of triterpene derivatives such as ergosterol. In T. harzianum the partial silencing of the erg1 gene gave rise to transformants with a higher level of sensitivity to terbinafine, an antifungal compound that acts specifically over the squalene epoxidase activity. In addition, these silenced transformants produced lower levels of ergosterol than the wild type strain. Finally, the silencing of the erg1 gene resulted in an increase in the expression level of the erg7 gene that encodes the oxidosqualene lanosterol-cyclase, another enzyme of the terpene biosynthesis pathway.

Antifungal Agents↗
PubMed2004

[Phosphotyrosine phosphatase SHP-1, somatostatin and prostate cancer].

We review the mechanisms involved in prostatic growth based on androgens and product of neuroendocrine secretion, with special reference to the role of somatostatin (SS) in the inhibition of neoplastic growth. Our contributions in the field confirm the antiproliferative effect of SS on the prostate is mediated by phosphotyrosine phosphatase SHP-1, that is present in human prostate. This enzyme plays a role in the control of prostatic cell proliferation and in the progression of prostate cancer. Besides, we consider its presence may determine the therapeutic potential of SS in the control of prostate cancer.

Biomedical Research↗
PubMed1999

Hematologic parameters of the Spanish ibex (Capra pyrenaica).

Thirteen hematologic parameters were measured in 52 Spanish ibexes (Capra pyrenaica) from Sierra Nevada Natural Park, southern Spain. The animals were captured, maintained in captivity, and physically restrained for blood collection. We compared hematologic values for healthy ibexes with animals infected with sarcoptic mites and animals treated for scabies and recovered. Ibexes with scabies showed a decreased number of erythrocytes, a higher mean corpuscular volume and mean corpuscular hemoglobin, and increased numbers of band neutrophils. The number of lymphocytes was significantly higher in animals that had recovered from scabies as compared with infested ones. The only difference observed between healthy and recovered animals was in the number of monocytes, which remained significantly higher in animals that had recovered from scabies. No hemoparasites were found in this study.

Animals↗
PubMed1998

Non-conventional yeasts as hosts for heterologous protein production.

Yeasts are an attractive group of lower eukaryotic microorganisms, some of which are used in several industrial processes that include brewing, baking and the production of a variety of biochemical compounds. More recently, yeasts have been developed as host organisms for the production of foreign (heterologous) proteins. Saccharomyces cerevisiae has usually been the yeast of choice, but an increasing number of alternative non-Saccharomyces yeasts has now become accessible for modern molecular genetics techniques. Some of them exhibit certain favourable traits such as high-level secretion or very strong and tightly regulated promoters, offering significant advantages over traditional bakers' yeast. In the present work, the current status of Kluyveromyces lactis, Yarrowia lipolytica, Hansenula polymorpha and Pichia pastoris (the best-known alternative yeast systems) is reviewed. The advantages and limitations of these systems are discussed in relation to S. cerevisiae.

Gene Expression Regulation, Fungal↗
PubMed1998

Participation of T lymphocytes in cutaneous allergic reactions to drugs.

Immunological mechanisms implicated in drug allergic reactions are not yet well understood, but there is 'in vivo' and 'in vitro' evidence that T lymphocytes are involved in these hypersensitivity reactions. The cutaneous lymphocyte-associated antigen (CLA) is the skin homing receptor and is involved in targeting a skin-selective memory T lymphocyte to cutaneous sites of chronic inflammation. We have seen that CLA expression is increased in circulating T lymphocytes of patients who develop a drug allergic cutaneous reaction, these cells are activated and their CLA values tend to become normal in parallel with the disappearance of skin symptoms, demonstrating that CD3+ CLA+ cells are involved in the immunological mechanisms responsible for the pathogenesis of the chronic inflammation process in cutaneous drug reactions.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1997

Molecular cloning of TvDAO1, a gene encoding a D-amino acid oxidase from Trigonopsis variabilis and its expression in Saccharomyces cerevisiae and Kluyveromyces lactis.

The DAO1 gene of Trigonopsis variabilis encoding a D-amino acid oxidase (EC 1.4.3.3) was isolated from genomic clones selected for their specific hybridization to synthetic oligodeoxyribonucleotide probes based on regions of the enzyme that have been conserved through evolution. The nucleotide sequence of the gene predicts a protein with similarities to human, pig, rabbit, mouse and Fusarium solani D-amino acid oxidases. The open reading frame of the T. variabilis DAO1 gene was interrupted by an intron. The Dao1p sequence displays two regions, one in the N-terminal section--the FAD binding site--and the other near the C-terminal region that contains conserved signatures found in all the D-amino acid oxidases. The three C-terminal amino acids suggest that the enzyme may be located in peroxisomes. Northern blot experiments showed that no transcriptional activation occurred in the presence of D-methionine. The cDNA encoding Dao1p was expressed in Saccharomyces cerevisiae and Kluyveromyces lactis. Both yeast species are able to synthesize a functional enzyme under the control of the GAL1 promoter. In K. lactis, up to six times more enzyme units per gram of dry weight are produced with a multicopy plasmid in comparison with the wild-type strain of T. variabilis. The yeast expression system we describe may constitute an alternative source for the production of D-amino acid oxidases at industrial level.

Amino Acid Sequence↗
PubMed1996

Effect of venovenous bypass on perioperative renal function in liver transplantation: results of a randomized, controlled trial.

Although venovenous bypass (VVBP) has been suggested to protect the kidneys during liver transplantation and its systematic use has therefore been recommended, this beneficial effect of VVBP has not been clearly demonstrated. In a prospective, randomized, controlled trial, 77 patients receiving liver transplants for chronic liver disease were allocated to be supported with VVBP (group 1, 38 patients) or not (group 2, 39 patients). Both groups were similar in relation to preoperative clinical and laboratory data and operative transfusion requirements. Inulin clearance and urinary beta(2)-microglobulin and N-acetyl-beta-D-glucosaminidase (NAG) excretion (to determine glomerular filtration rate and tubular damage, respectively) were measured at different perioperative periods (anesthesia induction, hepatectomy, anhepatic phase, biliary anastomosis, and 24 hours after surgery). A significant decrease in inulin clearance and increase in tubular damage markers were observed in the anhepatic phase, which only partly improved in the subsequent phases. No significant differences were observed between groups 1 and 2 at any perioperative phase, except during the anhepatic phase, in which a more marked renal function impairment occurred in group 2 patients. However, renal function on the 7th postoperative day and the need for hemodialysis/ hemofiltration during the 1st week were similar in both groups. Among 40 variables analyzed, only low mean arterial pressure at anesthesia induction was identified as an independent predictor for early postoperative severe renal failure (inulin clearance < 10 mL/min/1.73 m(2) at the 24th postoperative hour), with no significant relationship between this complication and the use of venovenous bypass. Renal function markedly deteriorates during liver transplantation, and renal impairment persists during the early postoperative period. Because VVBP support is not associated with any clear benefit in renal function, its systematic use does not seem to be justified.

Acute Kidney Injury↗
PubMed1993

Kinetic behaviour of a repressible acid phosphatase from the yeast Yarrowia lipolytica: a comparative study between the solubilized enzyme, the enzyme bound to cell-wall fragments and the enzyme bound to intact cells.

(1) The substrate specificities and types of inhibitors of a repressible acid phosphatase from the yeast Yarrowia lipolytica as solubilized enzyme, enzyme bound to cell-wall fragments and enzyme bound to the intact cell were found to be essentially the same. (2) A similar pattern for the activation of the enzymatic activity by ionic strength was found for solubilized enzyme, the enzyme in cell-wall fragments and the enzyme in intact cells. (3) v[S] studies with all three locations of the enzyme revealed non-linear Eadie-Hofstee plots with concave-up curves of the negative cooperativity type; these were correctly fitted with a rate equation of 2:2 degree polynomial quotient. In all cases, the same behaviour was obtained and no new kinetic properties were observed when the enzyme was bound to the cell-wall matrix with respect to the solubilized enzyme. (4) Inhibition by phosphate was characterized for the three locations of the enzyme by v[I] and v[S] studies. The same pattern of partial inhibition and non-Michaelian inhibition of 'non-competitive' nature was observed for all three forms. (5) The above results are interpreted in terms of the hypothesis that the cell wall of Y. lipolytica has a slight negative charge but behaves as a permeable matrix that does not lead to novel characteristics regarding the catalytic and regulatory properties shown by the enzyme molecule in free solution.

Acid Phosphatase↗
PubMed1993

[Team cohesiveness: opinions of a group of primary health care professionals from Salamanca].

OBJECTIVE: To assess the view of a group of Primary care professionals on their level of perception of group cohesiveness in their teams' work dynamic. DESIGN: A descriptive and sectional study. SETTING: Four urban health centres in Salamanca with a recognised teaching activity. PARTICIPANTS: Both health professionals and those outside the Health Service, working in Primary Care, who had been members of their teams for more than a year (N = 90). MEASUREMENTS AND MAIN RESULTS: Descriptive statistics and "Chi squared" tests were employed. PARTICIPATION: 72%. A high level of agreement on the need for team work (95.23%). They perceived their group cohesiveness as being very low (84.21% affirmed that they encounter problems of cohesiveness). The main statements concerning this lack of cohesiveness were: "lack of common objectives" (25.5%), "intolerance between workers" (20.13%), "work not shared" (19.46%) and "the taking of decisions individually" (19.44%). The main causes given were: lack of support from Management (23.74%) and too little training for team work (21.58%). CONCLUSIONS: There is a high degree of conviction that the team work model is the most efficacious way of developing Primary Care. However in three of the four teams questioned, there were serious problems preventing the teams' reaching an adequate level of group cohesiveness.

Adult↗
PubMed1992

The use of the University of Wisconsin (UW) and Euro-Collins (EC) solutions either alone or in a combined method.

From June 1988 to October 1990, a total of 100 orthotopic liver transplantations (OLTs) in 91 patients were performed at the Hospital Clínic of Barcelona. Euro-Collins (EC) solution was used as the flush and storage solution in 29 livers, and the University of Wisconsin (UW) solution was used in 24. A combined method, consisting of flushing and harvesting the liver with UW solution through the portal vein and with EC solution through the aorta, was used in the remaining 47 livers. Livers harvested using such a combined method showed substantially better postoperative function in terms of AST, ALT, and prothrombin activity than those harvested in EC solution alone. Although AST and ALT values were lower in patients whose livers were harvested using the combined method than with UW alone, differences were not significant. On the other hand, prothrombin activity was consistently better in the UW group. Bilirubin levels, platelet count, and bile output showed no difference among the three groups. We conclude that the combined use of UW and EC solutions for flushing and harvesting is not hazardous to human liver preservation and, in fact, may considerably reduce the amount of UW solution needed and, consequently, the costs.

Adenosine↗
PubMed1992

Changes in tropomyosin during primary culture of embryonic myocardiocytes.

We chose the Hamburger and Hamilton's stage 29 (HH 29) to investigate the expression of tropomyosin in chick myocardiocytes during 14 days on culture. Throughout 14 days of cell culture, changes in cell morphology were accompanied by a redistribution of tropomyosin in different cell compartments. We used FACScan, SDS-PAGE and densitometric analysis to quantify total cell tropomyosin and concentrations of this protein in different cell fractions. Tropomyosin was found mostly in the cytoskeletal fraction than in the cytoplasmic. When we compared the densitometric values from SDS-PAGE of cells in different stages of development we found that in HH 19, tropomyosin was more abundant in the cytoplasmic than in the cytoskeletal fraction. By HH 29, the two fractions had become inverted, and in HH 39, tropomyosin was clearly more abundant in the cytoskeletal than in the cytoplasmic fraction. In the IFI analysis, tropomyosin was found to label the Stress fiber-like structures (SFL) in different patterns depending on the area of the cell which expressed this protein.

Animals↗
PubMed1992

Quantification and distribution of troponin-T in cultures of chick embryo myocardiocytes.

We analyzed the distribution and labeling patterns of troponin-T, a protein involved in the regulation of striated muscle contraction, in myocardiocytes obtained from chick embryos in Hamburger and Hamilton's stage 25 and 39, and cultured for 8 days. Troponin-T expression was examined with indirect immunofluorescence, densitometry, fluorescence-activated cell sorting, electrophoresis and immunoblotting. The patterns of expression of troponin-T were compared with those of actin to determine possible correlations in different stages of chick embryo development and culture. Our findings show that in both stages of embryonic development, the cellular accumulation of troponin-T changed after 8 days of culture. Our results revealed a quantitative modification with time: after 4 days of culture there was a significant increase in this protein, followed by a slight additional increase after 8 days of culture. Flow cytometry findings confirmed these trends over time, showing a significant increase in positive cells after 4 days, followed by a smaller rise after 8 days of culture. In comparison with actin, this pattern was similar only in cells from Hamburger and Hamilton's stage 25 embryos.

Actins↗