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Biomedical subjects

B González

Publications and source records attributed to B González.

At least 19 recordsLinked to original sources
PubMed1992

Increased cytotoxicity of polyunsaturated fatty acids on human tumoral B and T-cell lines compared with normal lymphocytes.

Epidemiological and experimental data suggest that fatty acids may modulate the growth of tumor cells. We have analyzed the effect of different types of fatty acids, bound to serum proteins in physiological conditions, on the lipid composition and growth of human neoplastic B and T-cell lines and compared their effect on normal lymphocyte proliferation. Fatty acids with 0 to 2 unsaturations (stearic, oleic, and linoleic), at concentrations up to 50 or 100 microM did not significantly affect the proliferation of leukemic cells. However, long-chain polyunsaturated fatty acids (PUFA), and mainly docosahexaenoic (22:6, n-3), were cytotoxic at concentrations greater than or equal to 20 microM after 48-72 h in culture. Simultaneous supplementation with vitamin E restored normal cell growth. The amount of end-products of lipid peroxidation in cells correlated with the observed toxicity but the amount of superoxides did not. Fatty acid supplementations increased cell triacylglycerol content but did not affect the degree of unsaturation of phospholipids, cholesterol/phospholipids molar ratio, or membrane fluidity. Glutathione-S-transferase activity was low in Raji and CEM cells, moderate in lymphocytes and high in Ramos cells and did not increase with supplementations. The proliferation of normal lymphocytes, which produced lower amounts of end-products of lipid perodixation, was not inhibited, but in some cases stimulated, by PUFA (with the exception of 30 microM 22:6). The extension of these results to situations in vivo could lead to use of PUFA for delaying leukemia progression or in adjuvant chemotherapy.

Burkitt Lymphoma↗
PubMed1992

Therapeutic efficacy and safety of the new antimycotic sertaconazole in the treatment of cutaneous dermatophytosis.

7-Chloro-3-[1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethoxy-methyl] benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) is a new antimycotic which, in experimental infection studies, proved to possess potent antifungal activity. In a randomized, parallel, double-blind trial, the activity of sertaconazole cream was studied in 20 patients suffering from superficial mycoses caused by dermatophytes, confirmed by microscopic examination (KOH) and culture test. The patients, who were included in accordance with microbiological, microscopic and clinical criteria, were divided into two groups of 10 and were treated with sertaconazole 1% or sertaconazole 2% (cream) twice a day for 28 days. Both treatments achieved a total cure of the disease, with a cure being reached in a shorter time in the group of patients treated with sertaconazole 2%. No undesirable effects or statistically significant changes in the blood tests conducted at the end of the trial were observed. The results of the trial show that sertaconazole 2% cream is more effective. In view of the advantages offered by topical therapy over systemic therapy and of the good results obtained in patients with dermatophytosis, sertaconazole may represent an important advance in the therapy of superficial dermatophytoses.

Adult↗
PubMed1991

Effect of alpha-fetoprotein and albumin on the uptake of polyunsaturated fatty acids by rat hepatoma cells and fetal rat hepatocytes.

The uptake of polyunsaturated fatty acids by rat hepatoma cells and fetal hepatocytes has been studied using albumin and alpha-fetoprotein (AFP) as carrier proteins. Both types of cells took up linoleic (18:2(n-6)) and linolenic (18:3(n-3)) fatty acids at the same rate when they were added complexed either to albumin or AFP at a 1:1 molar ratio. At 37 degrees C a greater incorporation of arachidonic acid (20:4(n-6)) and mainly docosahexaenoic acid (22:6(n-3)) was observed when these acids were bound to albumin (6.5 nmol 20:4(n-6); 6.4 nmol 22:6(n-3) /million cells) as compared to AFP (5.5 nmol 20:4(n-6); 4.3 nmol 22:6(n-3)/million cells). The 20:4(n-6) and 22:6(n-3) uptake seems to be inversely related to the apparent association constants (k'a) between these fatty acids and both proteins (1.3 and 1.5 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for albumin; 6.4 and 54.0 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for AFP). Experiments carried out at 4 degrees C indicated that binding of 20:4(n-6) (0.83 nmol/million cells in presence of albumin; 2.16 nmol/million cells in presence of AFP) and 22:6(n-3) (0.83 nmol/million cells in presence of albumin; 1.32 nmol/million cells in presence of AFP) by cell membranes was also inversely related to the k'a of these proteins. At 4 degrees C, the k'a of AFP and albumin for 20:4(n-6) and 22:6(n-3) changed considerably (12.7 and 9.6 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for albumin; 3.9 and 14.6 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for AFP) with respect to the k'a calculated at 37 degrees C. Hence, k'a values were higher for albumin and lower for AFP than the corresponding values at 37 degrees C. It was concluded that uptake by cells and interaction of fatty acids with cell membranes depend mainly on the k'a of fatty acids and carrier proteins at equilibrium.

Animals↗
PubMed1991

A double staining technique for simultaneous demonstration of astrocytes and microglia in brain sections and astroglial cell cultures.

We developed a double staining technique for simultaneous demonstration of astrocytes and microglial cells in histological brain sections and cell cultures. The procedure included a histochemical stain specific for microglial cells and an immunocytochemical stain specific for astroglial cells, with postponement of the final visualization of the staining products until both reactions had been performed. First, microglial cells were specifically but invisibly labeled by histochemical reaction for nucleoside diphosphatase (NDPase). Then the astroglial cells were labeled by performing the first parts of the immunocytochemical reaction for glial fibrillary acidic protein (GFAP). Finally, in a series of intervening steps, the NDPase reaction product was visualized and stabilized by treatment with ammonium sulfide and silver nitrate, while the 1-naphthol basic dye method was used to visualize the GFAP immunoreactive product. As an end product, the NDPase-positive microglial cells were brown and the GFAP-reactive astroglial cells blue. The two types of glial cells were clearly distinguishable in vibratome sections of rat brain tissue and in primary astroglial cell cultures, and we never observed cells that stained for both NDPase and GFAP. When the GFAP antibody was replaced by the OX-42 antibody, which recognizes microglial cells and macrophages, double staining of microglial cells was observed. The staining protocol has wide applications in studies of the functional interactions between microglial and astroglial cells in the normal brain and in different pathological states with neuronal or axonal degeneration, just as it can be used for experimental studies in cell cultures.

Acid Anhydride Hydrolases↗
PubMed1990

Fatty acid metabolism in human lymphocytes. I. Time-course changes in fatty acid composition and membrane fluidity during blastic transformation of peripheral blood lymphocytes.

The time-course changes in fatty acid composition of human T-lymphocytes during blastic transformation were analysed, as well as the variations in membrane fluidity determined by fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH), using a fluorescence-activated cell sorter. The more important changes observed, in activated relative to quiescent cells, started after 24 h and consisted in an increase in the proportion of oleic (18:1(n - 9)), docosapentaenoic (22:5(n - 3)) and docosahexaenoic (22:6(n - 3)) acids and a decrease in that of linoleic (18:2(n - 6)) and arachidonic (20:4(n - 6)) acids. This represented a relative increase of 26% for 18:1, 56% for 22:5 and 84% for 22:6 in peripheral blood mononuclear cells (PBMC) and 35%, 182% and 94%, respectively, in purified T-lymphocytes, both activated for 72 h. The decrease in n - 6 fatty acids was of 42% for 18:2 and 14% for 20:4 in PBMC and 30% and 19%, respectively, for 72 h. The decrease in n - 6 fatty acids was of 42% for 18:2 and 14% for 20:4 in PBMC and 30% and phosphatidylethanolamine) rather than neutral lipids. The 18:1/18:0 ratio increased greatly in major cell phospholipids. The proportion of 20:4, 22:5 and 22:6 in phosphatidylinositol was not significantly altered after 72 h of activation. The molar ratio cholesterol/phospholipids was reduced in 72-h-activated lymphocytes (0.29) compared to quiescent cells (0.5). On the other hand, the stimulation of human T-lymphocytes caused a significant decrease in the order parameter (S) of DPH, according to the observed changes in lipid composition. After 72 h in culture, the S value for quiescent and stimulated T-lymphocytes was 0.530 and 0.326, respectively. In conclusion, the blastic transformation of human T-lymphocytes is associated with changes in lipid composition which modify the physical properties of their membranes. These modifications could modulate, in turn, the activity of membrane proteins implicated in the process of blastic transformation.

Cells, Cultured↗
PubMed1990

Fatty acid metabolism in human lymphocytes. II. Activation of fatty acid desaturase-elongase systems during blastic transformation.

The fatty acid desaturation-elongation ability of human T-lymphocytes during blastic transformation was determined both by gas-liquid chromatography and incubation with radiolabeled precursors. Human peripheral blood mononuclear cells (PBMC) were activated with phytohemagglutinin (PHA) and cultured in media supplemented with different fatty acids (18:0, 18:1(n - 9), 18:2(n - 6), 18:3(n - 3) and 20:4(n - 6)) at a final concentration of 30 microM. All the fatty acids added were elongated by activated PBMC and the maximal activity was observed on 20:4(n - 6) (a 25% of conversion to 22:4(n - 6)). Supplementation with stearic acid increased the proportion of oleic (from 21.4% to 23.7%) and eicosaenoic (from 3.1% to 5.7%) acids in cellular lipids, indicating the existence of a delta 9-desaturase activity. Supplementation with linoleic and linoleic acids increased slightly the cell content in their more unsaturated derivatives. Direct measurement of desaturase activities was performed by incubating quiescent and activated PBMC with [1-14C]stearic, [1-14C]linoleic and [1-14C]linolenic acids. Quiescent cells exhibited a very low delta 9-desaturase and no sign of delta 6-desaturase activity. A moderate and progressive activation of delta 9-, delta 6- and delta 5-desaturases was observed during blastic transformation of human PBMC. Up to 8% of 18:0 was converted to monoenes, 4% and 1.5% of 18:2(n - 6) was converted to trienes and tetraenes, respectively, and 14.5% of 18:3(n - 3) was converted to pentaenes. The maximal relative activities were found after 48 h of PHA-stimulation for delta 9-desaturase (around 90 pmol of 18:0 converted per 10(6) cells in the last 24 h) and at 72 h for delta 6- and delta 5-desaturases (around 75 and 140 pmol of 18:2 and 18:3, respectively, converted per 10(7) cells in the last 24 h). Although these activities are not enough to explain all the changes in fatty acid composition of human PBMC during blastic transformation, they may contribute to a more controlled cell phospholipid composition.

Acetyltransferases↗
PubMed1990

Histochemical demonstration of purine nucleoside phosphorylase (PNPase) in microglial and astroglial cells of adult rat brain.

The histochemical localization of enzymes associated with purine nucleoside metabolism indicates that glial cells might participate in the regulation of these compounds in the central nervous system. In the present study we examined the histochemical localization of purine nucleoside phosphorylase (PNPase) in sections from adult rat brain. Some sections were also sequentially stained immunocytochemically for astroglial or microglial cells utilizing glial fibrillary acidic protein (GFAP) or OX-42 antibodies, respectively. Our observations showed that PNPase was restricted to glial cells, whereas neurons always remained negative. Brain sections stained for both PNPase and GFAP showed that the GFAP-positive astroglial cells were always PNPase positive. Other PNPase-positive but GFAP-negative cells were also observed. These cells resembled microglial cells, and brain sections reacted for both PNPase and OX-42 confirmed this by showing that the major part of OX-42-positive microglial cells were PNPase positive. In these sections, the PNPase-positive but OX-42-negative cells present resembled astroglial cells. From our double staining experiments, we conclude that PNPase is present in both astroglial and microglial cells in normal adult brain.

Animals↗
PubMed1990

[Acute post-partum infarct of the myocardium secondary to a spontaneous dissection of the coronary artery].

A 38 year-old woman had an anterolateral wall myocardial infarction and acute left ventricular failure 11 days after a cesarean section. Coronary angiography performed 14 days later because of recurrent angina disclosed dissection of the left main coronary artery. She subsequently underwent aorto coronary bypass surgery uneventfully. Spontaneous coronary artery dissection is a rare entity that mainly affects women in peripartum periods and presents a high mortality rate.

Adult↗
PubMed1990

Linoleate and linolenate desaturation by rat hepatoma cells.

Morris 7777 rat hepatoma cells in culture possess high delta 6 and delta 5 desaturase activities over linolenic acid added to the medium as albumin or alpha-fetoprotein complexes. After 2 hours incubation with [1-14C] linolenic acid (7 microM), around 40% of the radioactivity was recovered in other polyene fatty acids, mainly pentaenes. After 24 hours incubation with this substrate the polyene derivatives raised to more than 60%. However, [1-14C] linoleic acid was poorly converted to other polyene fatty acids. Linoleic acid up to 58 microM concentration in the medium do not inhibited linolenic acid desaturation. Long-term supplementation with 50 microM linoleic or linolenic acid, which modified the fatty acid profile of hepatoma lipids, enhanced the desaturase activities against linoleic acid. Desaturase activities were not affected by the fatty acid protein carrier, alpha-fetoprotein or albumin.

Animals↗
PubMed1989

Increased synthesis and production of prostaglandin E2 by monocytes from drug addicts with AIDS.

We analysed the production of prostaglandin E2 (PGE2) by monocytes in 11 drug addicts with AIDS and opportunistic infections and in 13 controls. In three patients and six controls we isolated the PGE2 fraction from culture supernatants of purified monocytes (greater than 95%) incubated in medium containing (3H) arachidonic acid, using silicic acid columns. In two of three patients PGE2-fraction values (21.9 and 21.6 pmol/g protein) were significantly higher than controls (10 +/- 4). In eight AIDS patients and seven controls, PGE2 levels were determined by high-performance liquid chromatography and radioimmunoassay (HPLC and RIA). In three out of eight patients PGE2 levels were markedly higher (736, 419 and 208 pg/ml) than the mean + 2 s.d. values from controls (73 +/- 51). We tested the effect of PGE2 on the production of interleukin-2 by normal phytohemagglutinin-stimulated peripheral blood lymphocytes (PBL). There was a significant suppression of interleukin-2 production by PGE2 released from AIDS monocytes. PGE2 may be one of the factors involved in the severe immune dysfunction associated with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Benzaldehyde lyase, a novel thiamine PPi-requiring enzyme, from Pseudomonas fluorescens biovar I.

Pseudomonas fluorescens biovar I can grow on benzoin as the sole carbon and energy source. This ability is due to benzaldehyde lyase, a new type of enzyme that irreversibly cleaves the acyloin linkage of benzoin, producing two molecules of benzaldehyde. Benzaldehyde lyase was purified 70-fold and found to require catalytic amounts of thiamine PPi (TPP) and a divalent cation as cofactors. Optimal activity was obtained with a 1.0 mM concentration of Mn2+, Mg2+, or Ca2+. Gel permeation chromatography indicated a native molecular weight of 80,000, whereas the enzyme migrated in sodium dodecyl sulfate-containing polyacrylamide gels as a single polypeptide with a molecular weight of 53,000. Benzaldehyde lyase is highly specific; of a variety of structurally related compounds tested, only benzoin and anisoin (4,4'-dimethoxybenzoin) acted as substrates, their apparent Kms being 9.0 x 10(-3) and 3.25 x 10(-2) mM, respectively. A catalytic mechanism for the enzyme is proposed.

Aldehyde-Lyases↗
PubMed1988

Degradation of diarylethane structures by Pseudomonas fluorescens biovar I.

Pseudomonas fluorescens biovar I was isolated from a pulp mill effluent based on its ability to grow on synthetic media containing 1,2-diarylethane structures as the sole carbon and energy source. Analysis of samples taken from cultures of this strain in benzoin or 4,4'-dimethoxybenzoin (anisoin), showed that cleavage between the two aliphatic carbons takes place prior to ring fission. Intermonomeric cleavage was also obtained with crude extracts. Substrates of this reaction were only those 1,2-diarylethane compounds that supported growth of the bacterium. The purification and partial characterization of an enzyme that catalyzes the NADH-dependent reduction of the carbonyl group of benzoin and anisoin is also reported.

Alcohol Oxidoreductases↗
PubMed1988

Binding of BAL 31 RNA polymerase to PM2 DNA as determined by electron microscopy and protection against restriction endonuclease cleavage.

Specific binding sites of BAL 31 RNA polymerase on PM2 DNA have been mapped by protection against HincII and HindIII cleavage and by observation of enzyme-DNA complexes by electron microscopy. Nine specific binding sites were observed at map units 0.19, 0.20, 0.28, 0.54, 0.63, 0.65, 0.71, 0.72, and 0.75 by the first method. All these sites were confirmed by electron microscopy which, in addition, revealed another site at 0.05 map unit. Published nucleotide sequences of the region surrounding sites at 0.71 and 0.75 map units show the presence of consensus sequences for procaryotic promoters.

Bacteriophages↗
PubMed1985

Electron microscopic mapping of Thermus thermophilus RNA polymerase binding sites on plasmid pBR322.

The binding of RNA polymerase from the extreme thermophile T. thermophilus HB8 to plasmid pBR322 was measured by electron microscopy. DNA-protein complexes were prepared at 35 and 60 degrees C. At both temperatures the enzyme binds strongly to sites which coincide with promoters P1, P2, P3 and P4 present in pBR322. At 60 degrees C, an additional binding site appears, which is located between P3 and P4. There is a high degree of correlation between RNA polymerase binding sites and the location of A-T rich regions on pBR322 DNA.

Binding Sites↗
PubMed1978

[Personal experience in colonoscopy and polypectomy].

The purpose of this presentation is to point out the importance of this new diagnosis and treatment method, recently incorporated. The studies were done with the Fibroscope F9-A with doble channel, equipped with an desection smear for polipectomies and an extracting forceps. The patients arrive with their intestine perfectly cleaned with classical methods. This detail is most important for the polipectomies. If the local conditions aren't the desired, presence of bowels or barium of an previous enema, we postpone both, examination and polipectomy, because those are causes of false diagnosis in the first case or eventual accidents in the second condition. Regarding this, we had an performing doing a biopsy in an stenosing neoplasm of the sigmoid colon. We believe it convenient to prevent this complication, to reduce the air pressure before performing the biopsy. Of the 160 patients examinated, 54 had no patology, 32 had polips and of this group 4 had multiple poliposis, 4 had association with diverticulosis and 3 associated with neoplasm. (4 were neoplasm, 10 stenosis without mucous lesions, 1 villous adenoma, 1 megacolon and 1 rectitis). We made 12 polipectomies, 10 with the conventional technique and 2 associated with surgery. We had no accidents and one of them was an early stage of colon cancer.

Colonic Diseases↗
PubMed1975

[Team nursing].

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Nursing, Team↗