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Biomedical subjects

C Barroso

Publications and source records attributed to C Barroso.

At least 19 recordsLinked to original sources
PubMed2006

Upper limb tremor induced by peripheral nerve injury.

We report a patient with proximal right upper limb tremor, secondary to direct peripheral nerve lesion caused by prior thoracic surgery. Electromyography demonstrated neurogenic abnormalities and tremor in muscles innervated by the thoracodorsal and long thoracic nerves. Somatosensory evoked potentials, transcranial magnetic stimulation, and MRI of the cervical and thoracic spine were normal. Tremor persisted in REM and non-REM sleep. These findings suggest a peripheral generator.

Arm↗
PubMed2000

Promoting tolerance and moral engagement through peer modeling.

Behavioral journalism influences audiences by presenting peer modeling for cognitive processes that lead to behavior change. This technique was used in student newsletters promoting intergroup tolerance and moral engagement in a Houston high school with a diverse ethnic composition. Pretest (N = 393) and posttest (N = 363) cross-sectional comparisons of the student population in that school provided evidence of short-term (6 month) communication effects on attitudes and behavior. Tolerance and moral engagement increased among students in the school where behavioral journalism newsletters were distributed, and there was a corresponding reduction in hostile behavioral intentions and in reports of verbal aggression.

Adolescent↗
PubMed2000

Two kinesin-related proteins associated with the cold-stable cytoskeleton of carrot cells: characterization of a novel kinesin, DcKRP120-2.

We have previously described the biochemical isolation of 65 kDa and 120 kDa microtubule-associated proteins from carrot cytoskeletons. The 65 kDa MAPs have subsequently been shown to be structural MAPs that reconstitute 30 nm cross-bridges of the kind that maintain cortical microtubules in parallel groups. By exploiting its avid binding to microtubules, we have now devised a method for isolating MAP120 from protoplast extracts, and shown that it has properties of a kinesin-related protein. MAP120 segregates with the cold stable pool of microtubules in carrot cytoskeletons, whilst the 65 kDa MAPs are also associated with the cold-sensitive microtubules. On gradient gels, MAP120 resolves as two kinesin-like bands. We report the isolation of a carrot cDNA, DcKRP120-2, corresponding to a novel kinesin of the BimC class known to move to the plus ends of microtubules. Antibodies raised against specific expressed sequences recognize the upper band, while the lower band is recognized by antibodies to the tobacco kinesin-related protein, TKRP125. We have also isolated a partial genomic carrot DNA, DcKRP120-1, homologous to the motor region of tobacco TKRP125. Immunofluorescence of the two proteins produces different staining patterns. Anti-TKRP125 labels the cortical microtubules and the pre-prophase band, but anti-DcKRP120-2 does so only weakly. Both clearly stain the spindle and the phragmoplast, but in a proportion of cells anti-DcKRP120-2 strongly decorates the phragmoplast mid-line where the plus ends of the microtubules overlap. We discuss the potential roles of these proteins during the microtubule cycle.

Amino Acid Sequence↗
PubMed1999

Salt-specific regulation of the cytosolic O-acetylserine(thiol)lyase gene from Arabidopsis thaliana is dependent on abscisic acid.

The expression of Atcys-3A gene coding for cytosolic O-acetylserine(thiol)lyase, a key enzyme in cysteine biosynthesis, from Arabidopsis thaliana is significantly induced by exposure to salt and heavy-metal stresses. Addition of NaCl to mature plants induced a rapid accumulation of the mRNA throughout the leaf lamina and roots, and later on in stems, being mainly restricted to vascular tissues. The salt-specific regulation of Atcys-3A was also mediated by abscisic acid (ABA) since: (1) exogenous addition of ABA to the culture medium mimicked the salt-induced plant response by raising the level of Atcys-3A transcript, and (2) Arabidopsis mutants aba-1 and abi2-1 were not able to respond to NaCl. Our results suggest that a high rate of cysteine biosynthesis is required in Arabidopsis under salt stress necessary for a plant protection or adaptation mechanism. This hypothesis was supported by the observation that intracellular levels of cysteine and glutathione increased up to 3-fold after salt treatment.

Abscisic Acid↗
PubMed1999

Cysteine biosynthesis in Chlamydomonas reinhardtii. Molecular cloning and regulation of O-acetylserine(thiol)lyase.

A cDNA, Cys1ACr, encoding an isoform of O-acetylserine(thiol) lyase has been isolated from Chlamydomonas reinhardtii, using a PCR-based approach. The inclusion of dimethylsulfoxide in the PCR reaction has been demonstrated to be essential for the correct amplification of C. reinhardtii templates with complex secondary structures caused by a high G + C content. The deduced amino acid sequence exhibited highest similarity with plant O-acetylserine(thiol)lyase isoforms, indicating that the C. reinhardtii enzyme was structurally more similar to higher plant O-acetylserine(thiol)lyase than to the corresponding prokaryotic enzymes. The N-terminal extension present in Cys1ACr showed several characteristics of an organellar transit peptide, with a length typical for C. reinhardtii. Southern blot analysis suggested that the C. reinhardtii genome may contain a single copy of the organellar O-acetylserine(thiol)lyase gene. O-acetylserine(thiol)lyase activity was strongly induced by sulfur-deficient conditions (up to sevenfold the level observed in a sulfur-repleted cell culture) and required the presence of a nitrogen source. Northern blot analysis showed a different pattern of regulation of Cys1ACr to that observed at the activity level. To obtain an increase of transcript abundance a longer period of sulfur limitation was required, reaching a maximum level of approximately threefold Cys1ACr mRNA when compared with the level of a sulfate-grown culture.

Amino Acid Sequence↗
PubMed1998

The role of roots in cysteine biosynthesis by Arabidopsis thaliana.

O-Acetylserine(thiol)lyase (OASTL) enzyme catalyzes the cysteine biosynthesis in photosynthetic organisms. In mature Arabidopsis thaliana the highest activity level is observed in non-photosynthetic tissues like roots, that also show significant amount of protein detected by Western blot analysis. By means of specific probes for cytosolic and plastidic OASTL isoenzyme transcripts, cytosolic isoenzyme has been determined to be predominantly expressed in roots, while the expression of the plastidic isoform is high in both green and non-green tissues. Sulfur starvation produces an increase on the OASTL activity level in all the Arabidopsis organs examined, this effect being particularly significant in the aerial parts of the plant.

Arabidopsis↗
PubMed1997

Occurrence of binding sites for [125I] ANP in the myocardium but not in Purkinje fibers of the bovine heart.

Atrial natriuretic peptide has frequently been detected in the cardiac conduction system and has been shown to regulate some intracellular effects in Purkinje fibers. To determine if atrial natriuretic peptide works as an autocrine and/or paracrine hormone on cardiac Purkinje fibers, we examined the different parts of the conduction system in the bovine heart by use of in vitro receptor autoradiography. In no parts of the bovine conduction system were specific binding sites for [125I] atrial natriuretic peptide observed, whereas the ventricular myocardium exhibited a large number of [125I] atrial natriuretic peptide binding sites. This is the first morphologic study showing the presence of [125I] atrial natriuretic peptide binding sites in the ventricular myocardium and their absence in the conduction system. The present observations together with results obtained in studies using other methods strongly suggest that natriuretic peptide receptors are localized on ventricular myocytes.

Animals↗
PubMed1997

Tissue-specific expression of ATCYS-3A, a gene encoding the cytosolic isoform of O-acetylserine(thiol)lyase in Arabidopsis.

Atcys-3A from Arabidopsis encodes the cytosolic isoform of O-acetylserine(thiol)lyase that catalyzes the last step of cysteine biosynthesis. The Atcys-3A transcript is present in different organs of mature plants, being more abundant in roots and declining to 40-50% in rosette leaves and flowers. In situ hybridization studies have shown a high Atcys-3A signal in root tissues, mainly localized to the cortex and xylem parenchyma. In a flower before anthesis, the transcript is detected exclusively in anthers and sepals and evenly distributed throughout the receptacle of the flower. An unexpected observation from these studies is the highest expression of Atcys-3A mRNA found in trichomes of either leaf or stem. The presence of high levels of the transcript is observed very early in trichome cell development. This is the first report describing the cellular localization of any plant O-acetylserine(thiol)lyase mRNA. The high level of Atcys-3A expression in trichomes raises new aspects to the biological function of trichomes, related to sulfate metabolism.

Arabidopsis↗
PubMed1997

Neuronal nitric oxide synthase activation by vasoactive intestinal peptide in bovine cerebral arteries.

The participation of nitric oxide and vasoactive intestinal peptide (VIP) in the neurogenic regulation of bovine cerebral arteries was investigated. Nitrergic nerve fibers and ganglion-like groups of neurons were revealed by NADPH-diaphorase staining in the adventitial layer of bovine cerebral arteries. NADPH diaphorase also was present in endothelial cells but not in the smooth muscle layer. Double immunolabeling for neuronal nitric oxide synthase and VIP indicated that both molecules co-localized in the same nerve fibers in these vessels. Transmural nerve stimulation (200 mA, 0.2 milliseconds, 1 to 8 Hz) of endothelium-denuded bovine cerebral artery rings precontracted with prostaglandin F2 alpha, produced tetrodotoxin-sensitive relaxations that were completely suppressed by NG-nitro-L-arginine methyl ester (L-NAME) and by the guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline (ODQ), but were not affected by the adenylyl cyclase inhibitor 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ 22,536), nor by VIP tachyphylaxis induced by pretreatment with 1 mumol/L VIP. Transmural nerve stimulation also elicited increases in intracellular cyclic GMP concentration, which were prevented by L-NAME, and small decreases in intracellular cyclic AMP concentration. Addition of VIP to bovine cerebral artery rings without endothelium produced a concentration-dependent relaxation that was partially inhibited by L-NAME, ODQ, and SQ 22,536. The effects of L-NAME and SQ 22,536 were additive. VIP induced a transient increase in intracellular cyclic GMP concentration, which was maximal 1 minute after VIP addition, when the highest relaxation rate was observed, and which was blocked by L-NAME. It is concluded that nitric oxide produced by perivascular neurons and nerve fibers fully accounts for the experimental neurogenic relaxation of bovine cerebral arteries and that VIP, which also is present in the same perivascular fibers, acts as a neuromodulator by activating neuronal nitric oxide synthase.

Animals↗
PubMed1996

Errors evolution and analysis in antineoplastic drug preparation during one year.

We analyzed the errors occurring in the preparation circuit of cytotoxic mixtures of the Centralized Cytotoxic Preparation Unit during one year. Analysis of their evolution meant the investigation of twenty parameters susceptible to error. Each parameter was considered one error opportunity. Error has been defined either by the lack of data or mistake in the controlled parameter. In 4,734 preparations (94,680 parameters) there were 314 errors. The percentage of error per parameter in the first month of study was 0.74; at sixth was 0.34 and the last month was 0.26. Only in four months the day of maximum number of preparations coincided with the day of maximum number of errors. We conclude that the percentage of errors in the preparation process is low with a tendency to decrease and that the number of daily preparations is not the single factor that influences the production of errors.

Antineoplastic Agents↗
PubMed1996

Anesthetic efficacy of eutectic prilocaine-lidocaine cream in pediatric oncology patients undergoing lumbar puncture.

OBJECTIVE: To evaluate the efficacy of eutectic mixture of local anesthetics 5% (Emla) in reducing pain associated with lumbar punctures in children. DESIGN: Prospective, double-blind, randomized, placebo-controlled trial. SETTING: University pediatric hospital. PATIENTS: Eleven pediatric oncology patients (mean age 6.6 y, range 4-16) who underwent 31 lumbar punctures. MAIN OUTCOME MEASURES: The analgesic effect was measured by using two methods. The first was a 10-point visual analog scale reported by the patient and the second was an 8-point behavioral pain scale assessed by the nurse who applied the cream. RESULTS: Emla cream was associated with significantly lower pain scores than those with placebo as measured by the patient when the puncture was successful on the first attempt (2.0 +/- 1.6 Emla group, 3.8 +/- 1.9 placebo group; p < 0.05). CONCLUSIONS: The use of Emla cream may reduce pain substantially only in patients who undergo a successful lumbar puncture on the first attempt.

Adolescent↗
PubMed1995

A new member of the cytosolic O-acetylserine(thiol)lyase gene family in Arabidopsis thaliana.

A cDNA, Atcys-3A, encoding O-acetylserine-(thiol)lyase has been isolated from Arabidopsis thaliana. The deduced peptide sequence showed a high level of similarity with the bacterial counterpart, and a remarkable percentage of identity with other higher plant O-acetylserine(thiol)lyase genes. Sequence comparison and Southern blot analysis suggested that Atcys-3A was a new and different to the previously reported member of the cytosolic gene family in Arabidopsis. The Atcys-3A expression was activated by sulfur limitation, requiring a carbon and nitrogen source for maximal expression. A similar pattern of regulation was observed at the O-acetylserine(thiol)lyase activity level. Northern blot analysis also showed an organ-specific expression of Atcys-3A.

Amino Acid Sequence↗
PubMed1995

[Pleural effusion of non-neoplastic etiology in a patient with a rare form of myeloma].

Pleural effusions can be a manifestation of several nosological entities. Etiologic diagnosis involves a good clinical history, followed by thoracocentesis with pleural biopsy and eventually bronchoscopy or thoracoscopy. The differentiation between transudates and exudates, by the biochemical characteristics of the pleural effusions, can orientate the underlying disorder. It is known that there are more than 35 different etiological entities of exudative pleural effusions. However, pneumonia, malignancies, pulmonary embolism, abdominal disease and tuberculosis are the major causes (around 90%). Transudative effusions are more frequently due to congestive heart failure, renal or hepatic failure. The AA present a clinical situation of pleural effusion, the etiology of which was initially attributed to congestive heart failure, with a good response, clinical and radiological response to the treatment established. However the laboratory alteration persisted (anaemia, renal failure, acute inflammation). The subsequent study showed the existence of a rare syndrome, a Myeloma Ig M lambda that can lead to differential diagnosis with Waldenström's Macroglobulinemia, about which the authors make some theoretical considerations showing the difficulty in etiologic diagnosis of some pleural effusions.

Aged↗
PubMed1992

[Severity evaluation of ventilated patients at a respiratory intensive care unit with the APACHE II system].

APACHE II system, is a simple and inexpensive method to evaluate severity of Intensive Care Patients. In a 2 years period (between 1988 and 1990), grading severity using APACHE II system, was performed on 498 consecutive mechanical Ventilated Patients in a Respiratory Intensive Care Unit. APACHE II was higher in COPD patients, but patients with Pneumonia and Organophosphate Poisoning had higher mortality. Correlating the different components of APACHE II with the results, we verified that Prognosis was not influenced by the Previous Health Status. Mortality was higher with increasing age, in patients with COPD and Organophosphate Poisoning. APS was the most important index for prognosis. Patients with Pneumonia and Organophosphate Poisoning had the highest APS. The Authors conclude that APACHE II is an objective and not time consuming method to evaluate severity in ICU Patients. However indexes measured on the first 24 hours of ICU staying are a result of severity of illness, treatment performed and time elapsed before ICU admission, and, this may be a possible source of bias when comparing different Unit results.

Adolescent↗