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Biomedical subjects

M Delgado

Publications and source records attributed to M Delgado.

At least 163 records · Page 9Linked to original sources
PubMed1994

Vasoactive intestinal peptide modulation of adherence and mobility in rat peritoneal lymphocytes and macrophages.

In this work, the effects of vasoactive intestinal peptide (VIP) in a concentration range from 10(-13) to 10(-7) M were studied in vitro on two common activities of peritoneal rat lymphocytes and macrophages: adherence and mobility (spontaneous and chemotaxis). The results show that VIP stimulated the adherence of the two cells studied, and increased the macrophage mobility but decreased this activity in lymphocytes. Moreover, a specific protein kinase C (PKC) activator such as phorbol myristate acetate (PMA, 50 ng/ml) also stimulated significantly the adherence and chemotaxis of both macrophages and lymphocytes. By contrast, a PKC inhibitor, retinal (2 x 10(-5) M), decreased significantly these capacities. Macrophages incubated with both VIP and PMA in relation to those incubated with VIP or PMA showed an increase in adherence and chemotaxis, whereas in lymphocytes adherence was also increased but chemotaxis decreased. The incubation with forskolin (10(-5) M), an enhancer of intracellular cAMP levels, produced an inhibitory effect of the chemotaxis activity in both types of cells. VIP prevented this inhibitory effect of forskolin in macrophages but not in lymphocytes. In addition, VIP was chemoattractant for macrophages but not for lymphocytes. The present study proves that VIP proves that VIP has a coronary effect on the two principal and representative types of immune cells in the rat peritoneum: lymphocytes and macrophages, stimulating macrophage chemotaxis through PKC activation and inhibiting lymphocyte chemotaxis through adenylate cyclase activation.

Animals↗
PubMed1994

[Evaluation of the Chromotitre EIA test in the diagnosis of human brucellosis].

BACKGROUND: The aim of the study was to evaluate the diagnostic efficacy of Chromotitre EIA test for the diagnosis of human brucellosis and compare the same with other classical serologic test. METHODS: A prospective study was performed in 50 patients with active brucellosis. Thirty blood donors, 64 patients with different neoplastic and autoimmune infectious processes, 20 patients with history of brucellosis and 8 subjects with continuous exposure to Brucella at work were analyzed as the control group. RESULTS: Forty-five patients with brucellosis (90%) presented a positive IgM or IgG ELISA, 32 (62%) only IgM, 34 (68%) only IgG and 22 (44%) both immunoglobulins were positive. The sensitivity and specificity of ELISA test jointly evaluating IgM and IgG was 90 and 68%, respectively with these numbers being 62 and 98% and 68% and 38% for ELISA IgM and ELISA IgG. A moderate correlation was found between ELISA IgM with Bengal's Rose test (r = 0.53, p = 0.003) and sero-agglutination (r = 0.63, p = 0.0001) and ELISA IgG with the Coombs test (r = 0.55, p = 0.003). Only acceptable concordance was observed between ELISA IgM and sero-agglutination (kappa = 0.55, p = 0.0001). CONCLUSIONS: The ELISA test evaluated was very useful for the detection of IgM antibodies but was found to be insufficient with respect to IgG antibodies. Despite the slight diagnostic efficacy of the ELISA IgG the combined parallel use of both immunoglobulins achieved a performance similar to that achieved with the classical tests.

Adolescent↗
PubMed1994

[Isolation of several species of the genus Aspergillus from soil of intrahospital ornamental plants].

The earth of ornamental plants is one of the main reservoirs of Aspergillus type of fungi in hospital areas. We studied 174 ornamental interior plants from a hospital at Santiago. Samples were obtained from the soil surface and sowed in Sabouraud-glucose agar, adding streptomycin and G-penicillin. After 72 h of culture, at least one strain of Aspergillus was isolated from 140 samples (80.5%). The most frequently isolated strain was A fumigatus (129 samples), followed by A niger (75 samples). A fumigatus and A niger were the only isolated strains in 65 and 11 samples respectively. These findings confirm that ornamental plants can be important reservoirs of Aspergillus strains, a potential infectious agent for immunocompromised patients, in hospital areas.

Aspergillus↗
PubMed1993

Stimulation by vasoactive intestinal peptide (VIP) of phagocytic function in rat macrophages. Protein kinase C involvement.

The action of vasoactive intestinal peptide (VIP) on macrophages has not yet been studied, although there are studies that show an inhibitory action of VIP on lymphocyte functions. The present study shows that VIP in a range from 10(-12) to 10(-7) M increased significantly the phagocytosis and digestion capacities of rat peritoneal macrophages. The most effective concentration of VIP was 10(-9) M followed by 10(-8) M. With respect to the phagocytic capacity, the ingestion of cells (Candida albicans) or inert particles (latex beads) was stimulated significantly with all the concentrations used. The digestion capacity was analyzed through the production of superoxide anion, measured by the reduction of nitroblue tetrazolium (NBT). As with phagocytic capacity, superoxide anion production was increased by VIP in non-stimulated macrophages (incubated without latex beads) and even more in stimulated cells (incubated in the presence of latex beads). The study of the mechanism of action of this neuropeptide showed that protein kinase C (PKC) was activated in the presence of VIP concentrations from 10(-10) to 10(-8) M in a similar way to that found with a specific PKC activator such as phorbol myristate acetate (PMA, 50 ng/ml). PMA also stimulated significantly the phagocytosis and digestion capacities of rat macrophages. By contrast, a PKC inhibitor, retinal (20 microM), decreased significantly the phagocytosis and digestion capacities. These data show that VIP could stimulate these macrophage functions through PKC activation.

Animals↗
PubMed1993

Simultaneous determination of carbamazepine, phenytoin, phenobarbital, primidone and their principal metabolites by high-performance liquid chromatography with photodiode-array detection.

We have established a precise and accurate high-performance liquid chromatographic method for the simultaneous assay of carbamazepine, phenytoin, phenobarbital, primidone and their principal metabolites. This method has been used for the analysis of these drugs and the metabolites in serum, saliva and urine samples. Acetonitrile is used for the deproteinization of serum and saliva samples while solid-phase extraction is utilized for urine sample pretreatment. Samples of 2 microliters are injected onto a 3-microns ODS-Hypersil column (250 mm x 2 mm I.D.) with a column temperature of 40 degrees C. The drugs and metabolites are eluted with a mobile phase containing potassium phosphate buffer-acetonitrile-methanol (110:50:30, v/v/v) at a flow-rate of 0.2 ml/min. Signals are monitored by a photodiode-array detector at a sample wavelength of 200 nm with a bandwidth of 10 nm. These four commonly used antiepileptic drugs and their six metabolites are well separated from one another within 15 min. Within-day coefficients of variation (C.V.) are within 5% in most cases and between-day C.V. are from 2.32 to 4.75%. The recovery rates range from 95.12 to 104.42%. This method has the necessary sensitivity and linearity for routine therapeutic monitoring of both total and free drug levels and may be employed for pharmacokinetics studies of drug interactions and metabolism as well.

Anticonvulsants↗
PubMed1993

VIP gene expression in rat thymus and spleen.

Vasoactive intestinal peptide (VIP) is a neuropeptide with immunomodulatory properties. In the present study, we demonstrate VIP gene expression in cells of both thymus and spleen in the rat by in situ hybridization. In thymus sections, hybridization signal for VIP mRNA was found in cells in corticomedullary and medulla regions. In the spleen, cells were labeled at the outer area on the periarteriolar lymphoid sheath of the white pulp. Hybridization signal appeared to be in lymphoid cells. These findings suggest that lymphoid cells might produce VIP, which, if released, could exert a paracrine action on central and peripheral lymphoid organs. We suggest that VIP participates in the bidirectional communication between the nervous and the immune systems.

Animals↗
PubMed1993

Neonatal hypotonia.

The approach to a newborn with hypotonia should not differ substantially from that to an older patient. The examination may be more difficult to interpret, especially in evaluating mental status and muscle strength. However, laboratory studies such as serum enzymes, EMG, and muscle biopsy may be very specific in helping the neurologist to arrive at a diagnosis, even in premature infants.

Humans↗
PubMed1993

Determination of total and free carbamazepine and the principal metabolites in serum by high-performance liquid chromatography with photodiode-array detection.

A precise and accurate high-performance liquid chromatography (HPLC) method has been established for the simultaneous analysis of carbamazepine (CBZ), carbamazepine-10,11-epoxide (CBZ-E), and trans-10,11-dihydroxy-10,11-dihydro-CBZ (CBZ-H) in serum samples and their ultrafiltrates. CBZ and its metabolites are eluted in a 3-microM ODS-Hypersil column (250 x 2 mm) at a column temperature of 40 degrees C. The mobile phase is a mixture containing potassium phosphate buffer-acetonitrile-methanol (110:50:30, vol/vol/vol) at a flow rate of 0.2 ml/min. Signals are monitored by a photodiodearray detector with a main sample wavelength of 215 nm and a bandwidth of 10 nm. Coefficients of variation (CVs) for within- and between-day are within 5%, with the recovery rates ranging from 98.16 to 104.64%. This method has the necessary sensitivity and linearity for routine therapeutic monitoring of both total and free CBZ and its principal metabolites. Total serum concentrations of CBZ, CBZ-E, and CBZ-H obtained from 55 epileptic children were 12.58 +/- 4.42, 2.45 +/- 1.22, and 5.83 +/- 3.17 (mean +/- SD, micrograms/ml), respectively. Levels of free CBZ, CBZ-E, and CBZ-H were 2.59 +/- 0.93, 1.05 +/- 0.57 and 3.73 +/- 1.87, respectively. Free fractions of CBZ, CBZ-E, and CBZ-H were 20.98 +/- 4.34, 42.63 +/- 8.21, and 65.41 +/- 7.80%, respectively. CBZ-H and CBZ-E had larger CVs than did CBZ (54.34 and 49.75 vs 35.15%, respectively, for total levels, and 50.31 and 54.46 vs 36.22%, respectively, for free levels), as well as higher free fractions. Determination of both total and free concentrations and free fractions of CBZ and its metabolites, as well as their ratios, should provide additional needed information for therapeutic drug monitoring of CBZ.

Carbamazepine↗
PubMed1993

Role of endoscopic retrograde cholangiopancreatography in liver transplantation.

Biliary tract complications develop in 5-10% of patients undergoing liver transplantation. They should be differentiated from other causes of graft dysfunction. The role of endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis and treatment of these patients is analyzed in a series of 116 liver transplant patients. Nine patients (7.8%) were suspected to have biliary complications, and only four of them required immediate surgery because of early accidental T-tube removal and biliary tract stricture. The remaining five patients could be satisfactorily diagnosed and managed by ERCP which showed bile casts in the common bile duct in one case, and bile leaks in four cases, all of them being successfully resolved after endoscopic papillotomy. There were no complications related to the procedure. ERCP and endoscopic papillotomy is the technique of choice for diagnosis and treatment of biliary tract complications after liver transplantation.

Adolescent↗
PubMed1992

Determination of valproic acid by high-performance liquid chromatography with photodiode-array and fluorescence detection.

The derivatization of valproic acid and undecylenic acid with 4-bromomethyl-7-methoxycoumarin is described. The derivatives were detected by photodiode-array and fluorescence detectors. The optimum monitoring conditions and the stability of the suspension solution and derivatives were investigated. A high-performance liquid chromatographic (HPLC) method with isocratic or gradient elution has been established for the analysis. This method has been used for the determination of total and free valproic acid in serum. There is a satisfactory correlation between the results obtained by this HPLC method and those measured by the enzyme immunoassay. Some other common anti-epileptic drugs did not interfere with the analysis. The method is simple and fast and has better sensitivity and linearity than enzyme immunoassay. It is suited for routine therapeutic drug monitoring.

Chromatography, High Pressure Liquid↗
PubMed1992

An activated murine B cell lymphoma line (A-20) produces a factor-like activity which is functionally related to human natural killer cell stimulatory factor.

In the present article we show that supernatants derived from lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA)-stimulated A-20 B cell lymphoma are able to induce polyclonal immunoglobulin (Ig) secretion by normal B cells in a T-cell-dependent manner. This activity could be blocked by neutralizing monoclonal antibodies against interferon-gamma, but not by monoclonal antibodies against interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10 and granulocyte macrophage colony-stimulating factor (GM-CSF) or even a polyclonal antibody against tumor necrosis factor (TNF)-alpha. Furthermore, A-20 supernatants induced the production of measurable amounts of interferon-gamma by normal murine spleen cells and activates natural killer (NK) cells. Fractionation of factor-rich supernatants on a Sephacryl S-200 column revealed that the factor activity is located in the fractions corresponding to a molecular mass of 160-150 kDa and 80-70 kDa. The biological activities found in the A-20 supernatant are very similar to the ones described for the recently cloned human IL-12/NK cell stimulatory factor. These results suggest the existence of a murine analogous factor for the human IL-12 produced by A-20 B cell lymphoma.

Animals↗
PubMed1992

A crude extract of Artocarpus integrifolia contains two lectins with distinct biological activities.

The crude extract derived from seeds of Artocarpus integrifolia (jack fruit) contains two fractions with different biological activities for lymphocytes. One fraction is the D-galactose-binding lectin, jacalin, obtained by affinity purification on a D-galactose agarose column. The other, which is a component of the flow-through fraction (FT), is responsible for the mitogenic activity observed with human PBMC and murine spleen cells. In contrast, jacalin inhibits FT- and ConA-induced proliferative activity of human PMBC and murine spleen cells. This inhibition is not due to toxicity, because: (1) jacalin induces significant levels of IL-3/GM-CSF but not of IL-2 and/or IL-4 in murine spleen cells; (2) jacalin does not affect the capacity of these cells to secrete IL-2 or IL-4 as supernatants obtained from spleen cells sequentially stimulated with jacalin and ConA contain IL-2 and/or IL-4 as well as IL-3/GM-CSF. The ligand for the mitogen contained in the FT fraction is D-mannose as determined by sugar inhibition studies.

Animals↗
PubMed1992

Deletion delta F508 and clinical expression of cystic fibrosis-related liver disease.

A study of liver function in 108 adult cystic fibrosis patients showed that 20 had established liver disease, and that these had significantly better pulmonary function than the subgroup without liver disease. The relative risk of liver disease for homozygotes vs heterozygotes was 2:1 in our series. Four of the liver patients had a sibling with CF, but three of the sibships were discordant for liver disease. Environmental or genetic factors other than the deletion Delta F508 may influence the development of cystic fibrosis-related liver disease.

Adolescent↗
PubMed1992

Determination of free valproic acid: evaluation of the Centrifree system and comparison between high-performance liquid chromatography and enzyme immunoassay.

Valproic Acid (VPA) is an important drug for the treatment of several types of seizures because it has a wide spectrum of activity. Since VPA has an unusual nonlinear binding characteristic and a wide interindividual variation, monitoring of its free concentration can be helpful in patient management. The determination of unbound VPA is more difficult because an extra sample preparation step is needed and the concentration of free VPA is low. Free drug monitoring can assume a more important role if there is a refinement in the technology. A high-performance liquid chromatography (HPLC) method with isocratic elution has been established for the analysis of the 4-bromomethyl-7-methoxycoumarin (BrMMC) derivative of free VPA. This method has a better sensitivity, linearity, and precision than enzyme immunoassay (EIA). Ultrafiltration with the Centrifree system was evaluated for the sample preparation. The influence of centrifuge times, relative centrifugal forces, and the starting sample amounts on the final results of the ultrafiltration were investigated. There was a satisfactory correlation between the free VPA levels determined by the HPLC method and the concentrations obtained by EIA. The total and free VPA were determined on 100 samples from 36 patients. The total VPA levels were in a range of 25 to 208 micrograms/ml, free VPA concentrations ranged from 1.92 to 55.75 micrograms/ml with the free fractions from 7 to 37%.

Anticonvulsants↗
PubMed1991

Infant, neonatal, postneonatal and perinatal mortality in Spain, 1975-1984. Interregional and interannual differences.

The national infant, neonatal, postneonatal and perinatal mortality in Spain does not reflect the differences which exist among regions. The aim of the present study is to demonstrate and to quantify these differences, as well as their annual trends. We have also attempted to define groups of regions presenting similar rates. The results of the study confirmed a decrease in all mortality rates during the analyzed period. Regions were grouped according to their rates. Differences between the top and the bottom groups (with the lowest and the highest rates, respectively) resulted in statistical significance. However, the differences between these and the middle groups were not sharply defined. In addition, a clear geographic aggregation was evidenced in both top and bottom groups. These differences are mainly due to economic and sanitary factors.

Analysis of Variance↗
PubMed1991

Regulation of the expression of mitogen-regulated protein (MRP; proliferin) and cathepsin L in cultured cells and in the murine placenta.

The genes encoding mitogen-regulated protein (MRP; also called proliferin; PLF) and procathepsin L (CL; also called major excreted protein; MEP) are expressed to high levels in the mouse placenta. Although they are both regulated by epidermal growth factor (EGF) and fibroblast growth factor (FGF) in 3T3 cells, expression of these genes is differently regulated with growth state. The expression patterns of MRP and CL as a function of murine development are also different. Basal and growth factor-stimulated levels of MRP expression are much higher in growing than in quiescent 3T3 cells, whereas CL levels are similar. These changes in gene expression in cultured quiescent cells parallel the changes in MRP and CL expression observed in the late-gestational quiescent placenta. These results suggest growth factors may regulate the expression of these genes, but other influences also regulate the expression of MRP and CL in vivo.

3T3 Cells↗
PubMed1990

Relationship of 4F2 antigen with local growth and metastatic potential of squamous cell carcinoma of the larynx.

The 4F2 antigen is a cell-membrane glycoprotein which arises early in the G0-G1 phases of the cell cycle. This molecule is present in all established human cell lines and most malignant human cells. The authors used an indirect immunophosphatase method to study 50 squamous cell carcinomas of the larynx and ten lymph-node metastases, corresponding to six primary tumors, for 4F2 expression. The tumors showed several patterns of 4F2 staining which were correlated with different behaviors and prognoses of the neoplasms. Three different patterns (no staining, peripheral staining, and diffuse 4F2 expression) are described as are their relationships with metastatic behavior of the carcinomas. Tumors with metastases were found only in the third group (P = 0.0001). These results led to the following conclusions: (1) the 4F2 antigen is present in squamous cell carcinomas; (2) its distribution reflects the tumor-spreading pattern; and (3) it correlates with differentiation and metastatic behavior.

Antibodies, Monoclonal↗