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Biomedical subjects

E Navarro

Publications and source records attributed to E Navarro.

At least 109 records · Page 6Linked to original sources
PubMed1988

The b-32 protein from maize endosperm, an albumin regulated by the O2 locus: nucleic acid (cDNA) and amino acid sequences.

The cDNA coding for the b-32 protein, an albumin expressed in maize endosperm cells under the control of the O2 and O6 loci, has been cloned and the complete amino acid sequence of the protein derived. A lambda gt11 cDNA library from mRNA of immature maize endosperm was screened for the expression of the b-32 protein using antibodies against the purified protein. One of the positive clones obtained was used to isolate a full-length cDNA clone. By Northern analysis, the size of the b-32 mRNA was estimated to be 1.2 kb. Hybrid-selected translation assays show that the message codes for a protein with an apparent molecular weight of 30-35 kDa. The nucleotide sequence shows that several internal repeats are present. The protein has a length of 303 amino acid residues (mol. wt. 32430 dalton) and its sequence shows the following features: no signal peptide is observable; it contains seven tryptophan residues, an amino acid absent in maize storage proteins; polar and hydrophobic residues are spread along the sequence; several pairs of basic residues are present in the N-terminal region; the secondary structure allows the prediction of two structural domains for the b-32 protein that would fold up giving rise to a globular shape. The cloning of this gene may help in understanding the role of the O2 and O6 loci in regulating the deposition of zein, the major storage protein of maize endosperm.

Amino Acid Sequence↗
PubMed1988

Release of prostaglandin E2 from brain of cat: II. In vivo studies on the effects of adrenergic, cholinergic and dopaminergic agonists and antagonists.

This study examined the effect of several neurotransmitters, receptor agonists and antagonists on the release of prostaglandin E2 (PGE2) from brain. Levels of PGE2 were measured in consecutive 30-min samples, collected from ventriculocisternal perfusions (100 microliters/min) in chloralose-urethanized cats, before, during and after the addition of carbachol, norepinephrine (NE) and dopamine (DA). Samples were submitted to acid organic extraction and radioimmunoassay (RIA) with a specific antibody. Displacement curves of ligand binding with control and stimulated samples were parallel to those observed with PGE2. The addition of carbachol (10(-4) M) to the perfusate resulted in a significant increase in the levels of PGE2 from 600 +/- 259 pg PGE2/min during the control period up to 1306 +/- 429 pg PGE2/min during the perfusion (P less than 0.02). Though NE (10(-3) M) and isoproterenol (10(-3) M, beta) were without effect, methoxamine (10(-3) M, alpha 1), but not ST-91 (an alpha 2-agonist), produced an increase in secretion of PGE2. This increase was blocked by phentolamine (10(-3) M). The addition of DA (10(-4) M) produced a fall from control levels of 642 +/- 185 pg PGE2/min to 290 +/- 101 pg PGE2/min (P less than 0.02). These results suggest that the central activation of selected populations of receptors will alter basal levels of PGE2 in the extracellular space.

Adrenergic alpha-Agonists↗
PubMed1988

Radiocesium concentration in migratory birds wintering in Spain after the Chernobyl accident.

Levels of 137Cs and 134Cs resulting from the Chernobyl nuclear accident were studied in 195 birds that winter in two regions of Spain. Only five of the 12 species examined were contaminated. The average values for 137Cs vary between 1.6 and 41 Bq kg-1 fresh. In particular, the contamination for song-thrushes (Turdus philomelos) are compared between the regions of Extremadura and Valencia, 350 km east of Extremadura at the same latitude. The results show that the contamination of birds wintering in Spain decreases from east to west. The whole-body dose commitment for humans consuming these contaminated birds was calculated. The values are well below the established ICRP guideline.

Accidents↗
PubMed1988

Size changes of a growth hormone- and prolactin-producing adenoma during and after sandostatin treatment.

A 46-year-old woman with acromegaly and marked hyperprolactinemia was treated chronically with sandostatin (50 micrograms b.i.d. up to 100 micrograms t.i.d.). Plasma growth hormone (GH) was reduced by 90% of basal values and prolactin (PRL) dropped from initially 204 to 74 ng/ml. Serial CAT scans detected a volume reduction of the pituitary adenoma of 46.7%, but discontinuation of therapy was followed by re-expansion of the tumor. Tissue collected at transsphenoidal adenomectomy was examined by immunohistology and found positive for both GH and PRL. This characteristic would explain the dual hormonal response to the specific GH inhibitor sandostatin.

Adenoma↗
PubMed1986

A multiple sample immunoblotting system (MSIS) for the intrinsic detection of antinuclear autoantibodies.

A multiple sample immunoblotting system (MSIS) is described. The MSIS permits the detection and classification of antinuclear antibodies (ANA) according to the pattern of antigenic polypeptides recognized in four different extracts: calf thymus whole tissue, nuclear extract, and two ammonium sulphate fractions of the nuclear extract. The procedure permits the classification of anti-RNP, anti-SS/B and anti-Sm, and the detection of new ANAs in sera from SLE patients. The reaction patterns presented are specific and unambiguous, and make the use of validated control sera unnecessary.

Antibodies, Antinuclear↗
PubMed1985

Sociocultural effects in neuropsychological assessment.

The group selected for this evaluation consisted of 109 normal people with an average age of 25, coming from two different sociocultural levels (high and low) of Mexico City. All were completely evaluated by Luria's battery for neuropsychological assessment, adapted by Ardila, Ostrosky, and Canseco, 1981. This group of tests measures nine different areas: Motor Functions, Somatosensory Knowledge, Auditory Knowledge, Visuospatial Knowledge, Cognitive Processes, Language, Reading, Writing and Basic Calculations. For all of these, the higher performance standards were achieved by the subjects from the high sociocultural level. A significant interaction between sociocultural level and sex was observed. The differences between sexes appear only in subjects from the low sociocultural level. Factor analysis of the battery revealed that the most sensitive items to sociocultural level were those related on one hand, to the handling of complex structural and conceptual aspects of language and on the other hand, to the organization of motor sequences and in general motor programming. Research related to the differences found is reviewed and implications for clinical assessment are discussed.

Adult↗
PubMed1985

[Metabolic effects of exposure to air and the post-aeration response in the intertidal anthozoan Actinia equina L].

Metabolic adjustments occurring during air exposure have been studied in a population of Actinia equina submitted to long-lasting emersion periods. Oxygen consumption upon reimmersion seems to account for the discharge of an oxygen debt related to the accumulation of end-products derived from anaerobic pathways. Incorporation of radioactive labelled glucose into both submerged and air exposed animals has allowed identification of these final products. A correspondence between the length of exposure-time and the amount of oxygen debt is encountered, which parallels the evolution of the rate of radioactivity incorporation into amino acids. Increasing levels of amino acid synthesis from glucose in the exposed conditions appear as the main metabolic feature.

Adaptation, Physiological↗
PubMed1984

Isolation and comparative studies of glycogen phosphorylase isoenzymes from lymphocytes and polymorphonuclear leucocytes.

Two glycogen phosphorylase isoenzymes have been identified in pig lymphocytes and polymorphonuclear leucocytes by DEAE cellulose chromatography. Both isophosphorylases have been further purified by affinity chromatography on Sepharose-AMP to almost homogeneity. The purified isophosphorylases were composed of subunits of molecular weight similar to the muscle and liver monomers. Isophosphorylase I was more related to the liver enzyme than isophosphorylase II based on immuno-inhibition experiments. Both isoenzymes were markedly different from liver and muscle phosphorylases in their activation by AMP, sodium sulfate and 1,2-dimethoxyethane.

Animals↗
PubMed1983

Ethanol and receptor function.

The effects of ethanol in vitro (21 and 42 mM) and in vitro (10 and 30 days of exposure) on the dose:effect curves for noradrenaline and acetylcholine in isolated auricles and uterus of rats, respectively, have been studied. Likewise, the acetylcholine-atropine interaction was studied in rat uterus under the above-mentioned conditions. Analysis of theoretical curves as well as pD2 and pA2 calculations revealed that ethanol causes changes in the tissue responses to the agents assayed which in turn may be an expression of modification in the receptor function.

Acetylcholine↗
PubMed1982

Indications for and limitations of laparoscopic ovarian biopsy.

A series of 213 patients with different menstrual patterns underwent laparoscopic visualization of the ovaries and ovarian biopsy in order to evaluate ovarian function. Menstrual patterns were classified in four groups: regular menstrual cycles, oligoamenorrhea, secondary amenorrhea and primary amenorrhea. Laparoscopic gross ovarian appearance was classified in four groups, also. Microscopic picture of the ovaries was also placed in four categories. Laparoscopic vision of the ovaries is not justified in regular menstrual cycle patients. Laparoscopic vision of the ovaries might be useful when menstrual disorders exist, especially in secondary amenorrhea. There is some controversy about whether primary amenorrhea patients should be biopsied. Histology may be important in x,y karyotype primary amenorrhea. Biopsy should be avoided in oligoamenorrhea patients. Premature menopause might be diagnosed histologically in patients with secondary amenorrhea. Gross ovarian appearance may help in the selection of patients for ovarian biopsy. Sclerocystic polycystic ovaries should be biopsied, but the procedure must be bloodless and correctly performed. Streak gonad biopsy is not without hazard, and ureteral injury has been reported. The diagnostic, prognostic and therapeutic value of ovarian biopsy should be balanced against the risk and expense of the procedure.

Amenorrhea↗