[Muscle uptake of 18FDG in positron emission tomography].
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Antineoplastic Agents↗
Biomedical subjects
A Maldonado
Publications and source records attributed to A Maldonado.
[The role of PET-FDG in questionable diagnosis of relapse in the presence of radionecrosis of brain tumors].
INTRODUCTION: Although CT and MR are sensitive techniques for the detection of cerebral tumours, both have limitations in distinguishing between tumour relapse (TR) and post-treatment radionecrosis (RN). PATIENTS AND METHODS: In this study we have determined the usefulness of metabolic imaging with PET-FDG in such situations. We assessed 70 patients with CNS tumours (22 low grade astrocytomas, 25 high grade astrocytomas, 3 oligodendrogliomas, 13 metastatic tumours and 7 other tumours. All had been treated with radiotherapy and other treatments such as radiosurgery, chemotherapy or different types of surgery, and presented clinical pictures which made it necessary to decide the differential diagnosis of relapse or radionecrosis. RESULTS: In the PET-FDG study visual and semiquantitative analysis was done by SUV (Standardized Update Value). Confirmation of the findings was obtained in 44 cases (24 TR and 20 RN). MR was doubtful or inconclusive in most cases, whilst with PET correct diagnosis was made in all cases. CONCLUSIONS: Metabolic imaging with PET-FGD is better than anatomostructural imaging techniques for differential diagnosis between tumour relapse and radionecrosis in CNS tumours which have been treated. Prospective studies are necessary for evaluation of SUV as a factor for prognosis of survival.
Adult↗
Successive negative contrast in one-way avoidance: effect of thiopental sodium and chlorpromazine.
The successive negative contrast effect on one-way avoidance was induced by shifting rats from a large reward (30 s spent in the safe compartment after completion of the avoidance response, pre-shift phase) to a small reward (1 s, post-shift phase). Under these conditions, the previously learned avoidance response deteriorated (negative contrast) when compared to a control group for which 'safe time' remained constant throughout the experimental situation (1 s). Thiopental sodium at a dose of 5 or 10 mg/kg, but not at 1, 2, 15 or 20 mg/kg i.p., abolished the negative contrast effect, and did not affect performance of the one-way avoidance task. Similar results were found when rats were treated with diazepam (1 mg/kg i.p.). Chlorpromazine at a dose of 0.5 or 1 mg/kg i.p. did not affect negative contrast, although at higher doses (2 or 3 mg/kg) there was an increase in the number of trials needed to reach the criterion for learning the avoidance response. This increase was evident in both pre-shift and post-shift phases, although only in the experimental situations involving a low level of reinforcement (1 s in the safe compartment). On the basis of these results, we tentatively suggest that the successive negative contrast effect in one-way avoidance in rats can be considered a useful pharmacological animal model for research into anxiety.
Animals↗
Acute pleuropneumonia in Barbary sheep (Amnotragus lervia) associated with Chromobacterium violaceum.
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Acute Disease↗
Swelling behavior and local topology of an L3 (sponge) phase.
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Journal Article↗
Differential effect of buspirone and diazepam on negative contrast in one-way avoidance learning.
The main aim of the present work was to investigate the effect of buspirone, a 5-HT1A receptor agonist, on successive negative contrast in one-way avoidance learning. Successive negative contrast was induced by shifting rats from a large reward (30 s spent in the safe compartment) to a small reward (1 s). Acute administration of buspirone (0.25, 0.5, 0.75 and 1.0 mg/kg i.p.) did not attenuate the contrast effect, as opposed to that observed for diazepam (1 mg/kg i.p.). The highest dose of buspirone used, however, did interfere with the learning of the avoidance response itself. Chronic buspirone (20 days, 0.5 and 0.75 mg/kg i.p.) did not have any effect on successive negative contrast either. Overall, these results could suggest that the 5-HT1A receptor is not involved in the negative contrast effect studied, quite different to that observed for the gamma-aminobutyric acid (GABA) system. The findings are compared to results obtained with animal models selectively sensitive to some anxiolytic drugs, as are the so-called 'conflict models'.
Animals↗
Development of highly specific monoclonal antibodies for the diagnosis of Vibrio cholerae 01.
We report here the development of two monoclonal antibodies, termed 5G8 and 5C12, belonging to the IgM and IgG1 class, respectively, suitable for the identification of Vibrio cholerae 01 in clinical and environmental samples. The specificities of the monoclonals were evaluated by ELISA and indirect immunofluorescent microscopy of microorganisms normally present in stool samples and with two bacterial panels. One panel included 72 potentially antigenically related bacterial strains and the second panel included 20 pathogenic bacterial strains involved in diarrhea cases. The results of these extensive analyses indicate that monoclonal antibodies 5G8 and 5C12 are highly specific and suitable for the clinical diagnosis of Vibrio cholerae 01 in human stool samples by indirect immunofluorescent microscopy. Although the antigenic sites recognized by these antibodies were not identified in this study, the observation of Western blot patterns suggested that 5G8 and 5C12 monoclonal antibodies bind to LPS epitopes, a good structural marker for the detection of V. cholerae 01 because it is present in all bacterial cell walls.
Animals↗
Serological survey for avian paramyxoviruses from wildfowl in aquatic habitats in Andalusia.
A serological survey for a range of avian paramyxoviruses (PMV) was carried out among wildfowl from southern Spain, 1990 to 1992, using the hemagglutination inhibition technique. We collected 579 sera from 24 avian families (18 aquatic and six non-aquatic). Antibodies were detected to all paramyxoviruses in waterfowl, with a notable prevalence of antibodies to PMV-8 (43%) and to a lesser extent PMV-6 (21%). By contrast, in non-aquatic species high antibody prevalences were detected only to PMV-2 (60%), particularly in sparrows (68%), while antibody prevalences to other PMV's were moderate or low.
Animals↗
Learned irrelevance is not the sum of exposure to CS and US.
In three experiments hungry rats received appetitive conditioning trials with a light that signalled the delivery of sucrose solution. In Experiment 1, prior exposure to uncorrelated presentations of the conditioned stimulus (CS) and unconditioned stimulus (US) retarded conditioning significantly more than did prior exposure to the CS alone. In Experiments 2 and 3, groups exposed to uncorrelated presentations of the CS and US within the same session conditioned significantly more slowly than groups given separate sessions of exposure to the CS followed by sessions of exposure to the US (or vice versa). Some part of the learned irrelevance effect depends on exposure to a zero correlation between the CS and US, perhaps because this promotes learning that the CS predicts no change in the probability of the US.
Animals↗
Increased plasma pancreastatin-like immunoreactivity levels in non-obese patients with essential hypertension.
DESIGN: Pancreastatin, a novel peptide, is known to inhibit insulin secretion and to have a glycogenolytic effect, and is present in many endocrine and chromaffin cells. Both the plasma insulin levels and the adrenergic activity accompanying insulin resistance have been shown to be increased in hypertensive subjects. Our working hypothesis was that pancreastatin might play a role in these pathological phenomena. METHODS: We studied the plasma pancreastatin level in non-obese essential hypertensive patients in response to an intravenous glucose load. We further measured the responses to the glucose challenge of insulin, glucagon, catecholamines and free fatty acids, as well as other factors related to insulin resistance (i.e. lipoproteins and apolipoproteins). We separated the hypertensive patients into three groups according to their response to an oral glucose-tolerance test: normoinsulinaemic, hyperinsulinaemic and glucose-intolerant. Matched normotensive control subjects were also studied. RESULTS: Pancreastatin levels did not change in the control group after the glucose challenge. However, all hypertensive patients showed an increase in plasma pancreastatin levels after glucose loading. The normoinsulinaemic hypertensive patients also had elevated basal pancreastatin levels. The increase in pancreastatin levels was in the ranking: normoinsulinaemic > hyperinsulinaemic > glucose-intolerant. The pancreastatin: insulin ratio showed that the secretion of pancreastatin and insulin may be regulated differently. Basal free fatty acid and glucagon levels were found to be elevated both in the hyperinsulinaemic and in the glucose-intolerant group. Fasting triglycerides levels were increased in all of the hypertensive patients. Other risk factors for coronary artery disease were also found to be altered: elevated very low-density lipoprotein-cholesterol and decreased high-density lipoprotein-cholesterol, with ranking: normoinsulinaemic < hyperinsulinaemic < glucose-intolerant. CONCLUSIONS: These results show an increase in pancreastatin levels in hypertensive patients, suggesting that pancreastatin might play a role in the pathophysiology of essential hypertension.
Adult↗
[ERCP/ES in the therapy of acute calculous pancreatitis].
In the medical press there are several data confirming the value of E.R.C.P. and E.E.S., in the therapeutical approach of acute lithiasic pancreatitis (A.L.P.). Nowadays it is a first line endoscopic technic on the therapeutical approach in A.L.P. permitting to clean out the biliary tree of stones, eliminating the etiological factor of the disease. It's the experience of the group of E.R.C.P./E.S.E. of Hospital dos Capuchos that we will present on this paper.
Acute Disease↗
Phase II trial of edatrexate in patients with advanced hepatocellular carcinoma.
BACKGROUND: The methotrexate analogue edatrexate (10-ethyl-10-deaza-aminopterin, or 10-EDAM) has demonstrated greater activity than methotrexate has against murine tumors and human tumor xenografts. Phase II trials of edatrexate have already demonstrated its activity against breast, lung, and head and neck carcinomas. A phase II trial of edatrexate was conducted in patients with advanced hepatocellular carcinoma. PATIENTS AND METHODS: Seventeen patients with previously untreated unresectable hepatocellular carcinoma were enrolled on the study. Edatrexate, 80 mg/m2 weekly for 5 weeks, was administered intravenously. The treatment course was repeated every 6 weeks. Tumor response was evaluated by computerized tomographic scan after 2 courses. RESULTS: No complete or partial responses were observed in this trial. Two minor responses, each lasting less than 12 weeks, were observed. Twelve patients had elevated serum alpha-fetoprotein (AFP) levels at entry into the study; 4 of the 12 patients experienced a > or = 25% decrease in the level of this tumor marker; 3 of the 4 had a > 50% reduction in AFP level. Grade 3 and 4 toxic effects were granulocytopenia, thrombocytopenia, anemia, oral mucositis, skin reactions, fatigue, anorexia, and diarrhea. CONCLUSIONS: Edatrexate administered at this dose and schedule appears to have little therapeutic efficacy against advanced hepatocellular carcinoma.
Adult↗
Diminished insulin receptors on erythrocyte ghosts in nonobese patients with essential hypertension independent of hyperinsulinemia.
Hypertension is associated with insulin resistance and dyslipidemia in a syndrome named X. Epidemiologic evidence also supports a link between hyperinsulinemia and blood pressure (BP), independent of obesity and non-insulin-dependent diabetes mellitus. To assess the possible role of insulin receptors in this syndrome, we studied insulin binding by erythrocyte ghosts in patients with moderate essential hypertension with or without fasting or postglucose hyperinsulinemia. We measured plasma glucose and insulin before and at 30, 60, and 120 min after administration of 75 g glucose in 62 hypertensive patients and 20 matched normotensive controls. Both groups had comparable age (mean 45 years) and waist/hip ratios (mean 0.88). Patients undergoing antihypertensive treatment did not receive antihypertensive medication for 3 weeks. Patients with fasting or postglucose hyperglycemia were excluded from the study. Insulin binding to erythrocyte ghosts was significantly decreased (p < 0.001) to almost half the values of controls (6.5% specific binding) in both patients with hyperinsulinemic (3.2% specific binding) and those with normoinsulinemic (3.9% specific binding) hypertension. Scatchard analysis demonstrated that this was due to a lesser number of insulin receptors. These data indicate that patients with essential hypertension can show decreased erythrocyte insulin receptors without detectable hyperinsulinemia.
Adult↗
Prevalence of antibodies to different Leptospira interrogans serovars in pigs on large farms.
A seroepidemiological survey was carried out in the province of Badajoz (south-western Spain) in order to determine the presence and spread of Leptospira interrogans. The 521 sera tested were drawn from breeding sows on 28 large farms (15 with fewer than 60 and 13 with over 60 breeders). Immunological testing was performed using the Martin-Pettit micro-agglutination technique. Pigs with titres equal to or greater than 1:100 were considered positive. Haemolysed and/or contaminated test sera were reprocessed following filter-paper treatment. A total of 10.56% of pigs tested proved positive, 39.28% of farms being affected. The following L. interrogans serovars were detected: pomona (6.53%), castellonis (1.15%), sejroe (1.15%), grippotyphosa (0.96%), australis (0.38%), hebdomadis (0.19%) and icterohaemorrhagiae (0.19%).
Animals↗
Susceptibility of Streptococcus suis to various antimicrobial agents.
A study was performed to determine the susceptibility of 59 S. suis strains, isolated from sick and healthy carrier swine, to a range of antimicrobial agents. The beta-lactamic group proved more active both in Kirby-Bauer and MCI tests. Trimethoprim-sulfamethoxazole emerged as an alternative drug in chemoprevention and treatment of S. suis infections.
Animals↗
Identification of Streptococcus suis isolated from swine: proposal for biochemical parameters.
A study was made of the biochemical profiles of 59 strains serotyped as Streptococcus suis, isolated from diseased and clinically healthy pigs. The following parameters are proposed for the identification of the species: Voges-Proskauer negativity, hydrolysis of esculin positivity, trehalose positivity, negativity for growth in 6.5% NaCl, and absence of beta-hemolysis on sheep blood agar. S. suis serotype 2 is negative for hippurate, pyrrolidonylarylamidase, and mannose.
Animals↗
[Characterization of a multiresistant strain of Vibrio cholerae O1, isolated from a case of cholera in Chile].
This report characterizes a multiresistant Vibrio Cholerae O1 strain, isolated from a patient with cholera, and investigates the mechanism of resistance. The analyzed strain was resistant to tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole. The resistance was mediated by a 101 megadalton plasmid that was transferred to the resultant of a conjugation assay between the multiresistant V. Cholerae strain and E. coli C-600 used as receptor strain, that acquired the triple resistance of the parental strain. The resistant V. cholerae strain had a Ogawa serotype, El Tor biotype and toxigenic capacity, demonstrated by ELISA and latex agglutination techniques. The biochemical features of the strain were identical to those of susceptible strains, except for the resistance to 10 and 150 ug o 129 vibriostatic factor. The emergence of plasmid mediated resistance to drugs of choice in the treatment of cholera must alert Chilean and Latin American health authorities, considering the cholera will continue affecting the region.
Anti-Bacterial Agents↗
[Characterization of Neisseria meningitidis isolated fron systemic infections. Chile, 1992-1993].
BACKGROUND: in Chile, all systemic infections caused by Neisseria meningitidis must be reported and the bacterial strain must be sent to a Reference Laboratory at the Instituto de Salud Pública de Chile (ISP). AIM: to report the characterization of strains of N. meningitidis isolated during systemic infections in Chile during the years 1992 and 1993. METHODS: the serogroup, serotype, subtype and antimicrobial susceptibility of every strain of N. meningitidis received at the ISP during 1992 and 1993 was studied. RESULTS: six hundred twenty eight strains of N. meningitidis were confirmed during 1992 and 1993. B serogroup was responsible of 91.1% and 94.7% of confirmed cases during 1992 and 1993 respectively. Serotypes and subtypes most frequently associated to B serogroup were B: 15: P1.3 (63.2%) in 1992 and 51.8% in 1993) and B:NT:P1.3 (11.7% in 1992 and 21.3% in 1993). In 1992, all strains were susceptible to penicillin, chloramphenicol, ceftriaxone and rifampicin. During 1993, 7 (2%) strains were found, for the first time in Chile, moderately susceptible to penicillin and rifampicin MIC90 increased fourfold in respect of 1992, although all strains continued to be susceptible to this antimicrobial. CONCLUSIONS: the increasing frequency of NT (non typified strains) isolation will demand the use of molecular biology techniques for their identification. The appearance of penicillin resistant strains in our country is worrisome.
Chile↗