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Biomedical subjects

J Castell

Publications and source records attributed to J Castell.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Study of an outbreak of hysteria after hepatitis B vaccination].

BACKGROUND: The aim of this study was to describe an epidemic outbreak of mass hysteria among adolescents which occurred after the immunisation with vaccine against hepatitis B and to determine the association with social variables related to the students. SUBJECTS AND METHODS: All the available information was evaluated and a questionnaire was designed, which included sociodemographic, clinics and school environment variables. A case-control study was conducted. The data were analyzed and outbreak rate and odds ratio with their respective CI (95%) were calculated. RESULTS: 18 cases (among a set of 74 students of seventh of EGB) were clustered in time (10.30-11 h) and space (class of seventh B). There was a clear association between the cases and the female sex (odds ratio = 5.4; CI 95% 1.3 - 23.8). As for the sociological variables there was a association with increasing household members (odds ratio = 5.3; CI 95% 1.3 - 23.4) and with lower educational levels of the father (odds ratio = 10.6; CI 95% 1.2 - 239.9). Among the affected a more unfavorable opinion of the school was detected. CONCLUSIONS: This outbreak fulfils 8 of the 11 criteria classically admitted as usual characteristics of a mass psychogenic illness episode. The sensorial transmission remains demonstrated supporting the hypothesis of a chain reaction.

Adolescent↗
PubMed1996

Intimal injury in a transiently occluded coronary artery increases myocardial necrosis. Effect of aspirin.

This study tested the hypothesis that intimal injury in a transiently occluded coronary artery limits myocardial salvage. The effect of intimal injury on reactive hyperaemia was investigated in 17 pigs submitted to a 30-min occlusion of the left anterior descending coronary artery (LAD), not resulting in myocardial infarction. Catheter-induced intimal damage increased local platelet deposition (99mTc) and reduced hyperaemia, but did not modify myocardial platelet or polymorphonuclear leucocyte content (myeloperoxidase activity) after 6 h reperfusion. To investigate the influence of intimal injury on the extent of myocardial necrosis secondary to a more prolonged coronary occlusion, and the role of platelets on this influence, 52 pigs were submitted to a double randomization (2x2 factorial design) to 250 mg i.v. aspirin vs. placebo and to coronary intimal injury vs. no coronary damage before a 48-min occlusion of the LAD and 6 h of reperfusion. After excluding 12 animals with reocclusion, coronary intimal injury was associated with larger infarcts (triphenyltetrazolium reaction) in animals receiving placebo (36.2+/-7.0% of the area at risk in animals with intimal injury vs. 10.8+/-3.9% in animals without coronary injury, P=0.006) but not in those receiving aspirin (20.3+/-6.5 vs. 21.7+/-6.5% of the area at risk in animals with and without intimal injury respectively). These results suggest that coronary intimal injury in the reperfused artery may have adverse effects on myocardial salvage by mechanisms other than reocclusion or embolization of platelet aggregates.

Animals↗
PubMed1995

Strategies for prognostic assessment of uncomplicated first myocardial infarction: 5-year follow-up study.

OBJECTIVES: Our aim was to use noninvasive studies early after infarction to assess medium-term prognosis in patients with a first uncomplicated myocardial infarction. BACKGROUND: Although the use of early postinfarction assessment to gauge short-term prognosis in myocardial infarction is well established, there have been few comprehensive evaluations of noninvasive methods for assessing medium- and long-term prognosis. METHODS: We prospectively studied 115 consecutive patients < 65 years old with a first acute uncomplicated myocardial infarction to evaluate the prognostic role of predischarge cardiac studies. These included submaximal exercise testing, thallium-201 scintigraphy, radionuclide exercise ventriculography, two-dimensional echocardiography, ambulatory electrocardiographic (Holter) monitoring and cardiac catheterization. All patients without complications were followed up > or = 5 years. RESULTS: During the follow-up period, 78 patients (68%) developed complications, which were severe in 37 (32%). Exercise thallium-201 scintigraphy yielded the highest percentage (77%) for correctly classified patients. It also had the highest predictive value for complications (97%) and severe complications (92%) when it was used in association with exercise testing and radionuclide ventriculography. The addition of cardiac catheterization did not improve on the predictive power of noninvasive studies. Four decision trees (exercise testing + echocardiography, exercise testing + radionuclide ventriculography, thallium-201 + echocardiography, thallium-201 + radionuclide ventriculography) allowed stratification of all patients in a high, intermediate or low risk category. The combination of thallium-201 scintigraphy and radionuclide ventriculography yielded the best results (90% predictive value for complications if the outcome of both tests was positive), but there were no significant differences with the other models. CONCLUSIONS: Any combination of a test detecting residual ischemia or functional capacity, or both (exercise testing or thallium-201 scintigraphy), and a test assessing ventricular function (echocardiography or radionuclide ventriculography) results in useful prognostic information in patients with an uncomplicated first acute myocardial infarction.

Adult↗
PubMed1995

[ST segment elevation during exercise test and perfusion scintigraphy in patients without infarction].

BACKGROUND: The features of perfusion scintigraphy in patients who show exercise-induced ST-segment elevation in the absence of previous infarction have been assessed in only a few reports. Therefore, we have evaluated our experience in a wide review of exercise 201-thallium scintigraphies. METHODS: 16,620 exercise 201-thallium scintigraphies, carried out between 1986 and 1993, have been retrospectively reviewed. Fourteen patients (0.8/1000) without previous infarction who were evaluated for chest pain showed ST-segment elevation. In all patients coronary arteriography was also available. RESULTS: Five patients were free from significant coronary artery stenoses, 6 had one-vessel disease, 2 had two-vessel disease, and the remaining patient had three-vessel disease. In 8 patients ST-segment elevation (up to 3-24 mm) was inferior, in 5 anterior and in 1 lateral. The radionuclide was injected during ST-segment elevation in 10 cases and before such elevation (which developed in the postexercise phase) in 4. In 3 out of these 4, which had angiographically normal coronary arteries, the scintigraphy was negative. In all cases where thallium-201 was injected during ST elevation, severe perfusion defects were detected corresponding to the localization of ST elevation. In the 4 patients with critical coronary stenoses, thallium-201 redistribution after 3 hours was partial. CONCLUSIONS: In patients without previous infarction and with exercise-induced ST-segment elevation, very severe perfusion defects are detected when the radionuclide has been injected during the crisis. Thallium-201 redistribution after 3 hours was not total in patients with fixed critical stenoses. When radionuclide injection preceded the crisis, the result of the scintigraphy was in agreement with the coronary anatomy.

Adult↗
PubMed1995

[Myocardial contractility and viability. A radionuclide tomography study using technetium-99m labeled isonitriles].

BACKGROUND: There are comparatively few studies evaluating the patterns of myocardial viability and its relation with contractility in patients with coronary artery disease. The aim of the present study was to quantify the viable and nonviable myocardium, using 99m-technetium isonitriles SPET, as related with left ventricular regional wall motion abnormalities. METHOD: 61 consecutive patients with coronary artery disease were investigated. The severity and extension of the defects were evaluated using a qualitative and quantitative analysis of the 99mTc-isonitriles SPET and compared with ventricular wall motion in contrast ventriculography. An uptake level of 40% of peak uptake or higher was considered as indicating viable myocardium. RESULTS: Of the 244 evaluated regions (4 per patient), 72 (29%) had normal perfusion, 100 (41%) were ischemic, 25 (10%) had a mild irreversible defect and 47 (19%) had a severe irreversible defect. Wall motion was normal in 176 regions (72%), 29 (12%) were hypokinetic, and 39 (16%) were akinetic of dyskinetic. The amount of viable myocardium in akinetic and dyskinetic regions (64.8%) was significantly different (p < 0.05) from that in hypokinetic (86.1%) and normokinetic (98.8%) regions. Visual assessment of uptake underestimated myocardial viability, as quantitative analysis disclosed that in 61% of akinetic and dyskinetic regions with severe irreversible defects there was more than 50% of viable myocardium. CONCLUSIONS: In 61% of akinetic and dyskinetic regions with a severe irreversible defect in perfusion scintigraphy positive viability criteria were found. Therefore, visual assessment of the myocardial perfusion studies using 99mTc-MIBI SPET underestimates viable myocardium. Tomographic studies with quantification of the uptake and defect extension are required for a proper evaluation of viable myocardium.

Adult↗
PubMed1994

[Isotopic renogram after captopril administration: clinical experience in the assessment of the hypertensive patient].

BACKGROUND: Isotopic renogram allows renal function to be estimated in both kidneys independently. The glomerular filtrate in ischemic kidneys is largely dependent on the tone of the efferent glomerular arteriolae and therefore on the concentration of circulating angiotensin II. METHODS: In 42 patients with severe high blood pressure in whom renal angiographic study was carried out for suspicion of vasculo-renal hypertension, an isotopic renogram using 99m Tc-DTPA as a tracer was performed in basal conditions and following the administration of 50 mg of oral captopril. RESULTS: In 21 patients both the angiographic examination and the post-captopril renogram were normal. In 16 patients in whom uni or bilateral stenosis higher than 50% of the lumen of renal artery was observed on angiographic examination, the post-captopril renogram showed changes. In 5 patients the angiography was normal while the renogram showed evaluable changes. No false negatives were observed in the post-captopril renogram, however the basal renogram was not demonstrative in 6 patients with stenosis of the renal artery. Sensitivity of the test was thus 100% and specificity 80%. The positive predictive value was 76% and the negative predictive value 100%. CONCLUSIONS: The post-captopril renogram may be a useful test in the functional study of renal behaviour in patients with vasculo-renal hypertension.

Adolescent↗
PubMed1994

Pericardial and myocardial localization of antimyosin in a case of acute myocarditis.

A 60-yr-old immunodepressed woman presented with acute perimyocarditis and cardiac tamponade complicating meningococcic infection. We had the opportunity to study her cardiac condition by injecting antimyosin during the acute phase. Images at 48 hr showed unexpected findings, with obvious localization of the tracer in the pericardial fluid, as well as myocardial uptake. Possible mechanisms for pericardial activity are discussed.

Antibodies, Monoclonal↗
PubMed1994

[An evolutionary study at 5 years of left ventricular systolic function in patients with an uncomplicated infarct].

INTRODUCTION AND OBJECTIVES: The aim of the present study was to compare the left ventricular ejection fraction in a first uncomplicated acute myocardial infarction before hospital discharge (initial ejection fraction) and 5 years later (late ejection fraction) and to evaluate the factors that may influence their possible changes. PATIENTS AND METHODS: Eighty-three patients (mean age: 52.2 +/- 7.5, range: 35-65 years) who had a first uncomplicated infarction were evaluated. Between 10 and 15 days after the acute episode, thallium perfusion scintigraphy, radionuclide ventriculography and coronary arteriography were carried out. The ventricular function was reevaluated after 5 years with radionuclide ventriculography. The population was classified according to the localization of infarction (anterior or inferior) and to the initial ejection fraction (< 30%, 30-50% and > 50%). The factors derived from predischarge exercise test, perfusion scintigraphy, radionuclide ventriculography and coronary arteriography that might have had an influence on ejection fraction changes were evaluated with bivariate and multivariate analysis. RESULTS: 1) left ventricular ejection fraction of anterior infarctions was lower than in inferior infarctions, both during the subacute phase (35.1 +/- 12.9 vs 48.1 +/- 12.1; p < 0.001) and after 5 years (41.3 +/- 15.1 vs 47.6 +/- 12.8; p = 0.006); 2) a significant increase in ejection fraction after 5 years was found in patients with anterior infarction (35.1 +/- 12.9 vs 41.3 +/- 15.1; p < 0.001), particularly in those with initial ejection fraction between 30-50% (38.8 +/- 5.9 vs 44.8 +/- 11.2; p < 0.001), and 3) no variable, either clinical or derived from exercise test, perfusion scintigraphy, radionuclide ventriculography or coronary arteriography, discriminated between the patients in whom ejection fraction decreased by more than 5% during follow-up nor those with anterior infarction and initial ejection fraction between 30-50% in whom ventricular function was improved after 5 years. CONCLUSIONS: Left ventricular ejection fraction of anterior infarctions shows a significant improvement after 5 years, particularly in the subgroups with initial ejection fraction between 30-50%. Predictive factors of such improvement have not been identified.

Adult↗
PubMed1993

[A cost-effectiveness analysis of prognostic studies in acute uncomplicated myocardial infarct].

INTRODUCTION AND OBJECTIVES: The prognostic assessment of the acute myocardial infarction may be obtained through clinical criteria, particularly in patients who are symptomatic during admission, or with several studies in patients without complications. The "effectiveness" of such investigations has been long studied, but not so their "efficiency", which analyses the relationships between costs and outcomes. The goal of the present study is to report the results of a cost-effectiveness analysis of various combinations of diagnostic tests. METHODS: One hundred and fifteen patients (age < 65) with uncomplicated first acute myocardial infarction were evaluated. In all patients exercise test, two-dimensional echocardiogram thallium-201 scintigraphy, radionuclide ventriculography, Holter monitoring and cardiac catheterization were performed. The effectiveness was calculated as the "global value" (rate of correctly diagnosed patients: complications prediction during the first year follow-up) of every of such tests combinations. We have used the direct differential costs estimated following the "Colegio Oficial de Médicos de Barcelona" standards. The index used in the cost-effectiveness analysis was the medium cost person/global value. The lowest index corresponded to the most efficient test combination. RESULTS: The highest effectiveness was found for the exercise test plus bidimensional echocardiography combination (global value = 0.64). At the same time it was the less expensive combination (medium cost = 14.444 ptas); therefore, its index was the lowest (21.724 ptas/patient). CONCLUSIONS: In patients with a first uncomplicated myocardial infarction, the performance of exercise test and echocardiogram is the less costly and most effective combination of studies for one year prognosis. In these patients, routine cardiac catheterization does not improve the results.

Chi-Square Distribution↗
PubMed1991

Uncomplicated first myocardial infarction: strategy for comprehensive prognostic studies.

To evaluate the prognostic role of combined cardiac studies (submaximal exercise test, thallium-201 scintigraphy, radionuclide exercise ventriculography, two-dimensional echocardiography, Holter monitoring and cardiac catheterization) in patients with a first acute myocardial infarction without complications during hospital admission, 115 consecutive patients aged less than 65 years were prospectively evaluated. The studies were carried out before hospital discharge and the patients were then clinically followed up for 12 months. During the follow-up period, 69 patients (60%) developed complications, which were severe in 23 (20%). Half of all complications and 70% of severe complications developed during the 1st follow-up month. Logistic regression analysis disclosed that the combination of studies with the highest predictive power for complications (probability of complications 99%) and severe complications (probability of severe complications 95%) was the association of exercise test + thallium-201 + echocardiogram. Four decision models (exercise test + echocardiography, exercise test + radionuclide ventriculography, thallium-201 scintigraphy + echocardiography, thallium-201 scintigraphy + radionuclide ventriculography) allowed the stratification of all patients in a particular risk category (high, intermediate or low). The best decision model was the association of thallium-201 scintigraphy + radionuclide ventriculography (probability of complications if both tests were positive 84%; probability of absence of severe complications if both tests were negative 88%), but there were no significant differences with the other models. Any association of a test detecting residual ischemia or functional capacity, or both (exercise test or thallium-201) and a test assessing ventricular function (echocardiography or radionuclide ventriculography) results in significant prognostic information in patients with an uncomplicated first acute myocardial infarction. Additional cardiac catheterization does not improve the predictive power of noninvasive studies, which should ideally be performed before hospital discharge because most complications develop during the 1st follow-up month.

Adult↗
PubMed1990

Fate of interleukin-6 in the rat. Involvement of skin in its catabolism.

Iodinated recombinant human interleukin-6 (125I-rhIL-6) was intravenously injected into rats and its fate was studied during 24 h. Between 10-20 min after a single-dose injection, 125I-rhIL-6 accumulated in liver as previously reported [Castell et al. (1988) Eur. J. Biochem. 177, 357-361]. After 1 h, the radioactivity disappeared from the liver and accumulated in skin, reaching 35% of injected 125I-rhIL-6 5-8 h after injection. No comparable accumulation of radioactivity was found in skin when [125I]iodide or rat serum 125I-albumin was administered. Finally the radioactivity was detected as [125I]iodide in urine. Autoradiographic analysis of skin sections 5 h after 125I-rhIL-6 injection showed radioactivity in the interstitium. When the experiments were carried out with [35S]rhIL-6, essentially the same results were obtained: a decrease in radioactivity in the liver after 20 min, and a substantial increase in skin 7 h after injection. In vitro experiments showed that 125I-rhIL-6 is degraded by rat and human fibroblasts, whereas no degradation was observed with rat hepatoma cells (Fao) or human hepatocytes. These observations suggest the involvement of skin in the catabolism of IL-6.

Animals↗
PubMed1989

O- and N-glycosylation lead to different molecular mass forms of human monocyte interleukin-6.

The biosynthesis and secretion of human interleukin-6 (IL-6) was studied in monocyte cultures stimulated with endotoxin. After labeling with [35S]methionine and immunoprecipitation with a specific antiserum one major (24 kDa) and four minor (27.5, 23.3, 22.5 and 21.8 kDa) molecular mass forms of IL-6 could be found in the cells and media. Incubation of monocyte media with sialidase and subsequently with endo-alpha-N-acetylgalactosaminidase, which cleaves Gal(beta 1-3)Gal-NAc from serine or threonine, led to the formation of only two forms of IL-6 with apparent molecular masses of 25 and 21.8 kDa. The latter had an electrophoretic mobility indistinguishable from that of 125I-labeled recombinant human IL-6. The results suggest that human monocyte IL-6 carries O-glycosidically bound carbohydrates with a Gal(beta 1-3)Gal-NAc core to which only sialic acid is bound. Differences in O-glycosylation are the major cause for the molecular heterogeneity of IL-6. A small part of IL-6 (27.5 kDa form) is in addition N-glycosylated. Incubation of monocytes with tunicamycin and 1-deoxymynnojirimycin and treatment of IL-6 with endoglucosaminidase H suggested that the 27.5 kDa form of IL-6 carries at least one N-linked complex-type oligosaccharide chain.

1-Deoxynojirimycin↗
PubMed1989

Fate and biological action of human recombinant interleukin 1 beta in the rat in vivo.

The plasma half life of recombinant human interleukin 1 beta (rhIL 1 beta) was determined in rats by measuring the disappearance of the radioactivity of 125I-labeled rhIL 1 beta from the circulation. The plasma clearance showed a biphasic behavior: an initial fast disappearance (half life of about 3 min) was followed by a second slower one (half life of about 4 h). Twenty minutes after a single-dose injection of 125I-labeled rhIL 1 beta most of the radioactivity was concentrated in kidneys, liver and intestine. rhIL 1 beta induced the synthesis of alpha 1-acid glycoprotein (AGP), alpha 1-cysteine proteinase inhibitor (CPI) and beta-fibrinogen mRNA in liver. Half maximal stimulation was elicited by approximately 3000 U of rhIL 1 beta per animal. The mRNA changes for AGP and CPI were followed by corresponding protein increases in serum. Twenty hours after rhIL 1 beta injection, serum AGP rose from 0.7 to 2.5 mg/ml. CPI increased from 0.3 to 1.9 mg/ml 25 h after administration of rhIL 1 beta. Within 20 h after rhIL 1 beta injection, albumin serum concentration showed a strong decrease, preceded by a reduction in hepatic albumin mRNA levels. Neither changes in albumin synthesis nor degradation can explain this decrease suggesting that other mechanisms such as increased transvascular permeability are involved.

Acute-Phase Proteins↗
PubMed1989

Transplant renography: 99m-Tc-DTPA versus 99m-Tc-MAG3. A preliminary note.

99mTc-MAG3 has been proposed as a replacement for both 131I-hippuran and 99mTc-DTPA on clinical grounds. We undertook a prospective preliminary study to ascertain whether 99mTc-MAG3 works better than 99mTc-DTPA in the follow up of renal transplant recipients. Seventeen patients (21 renograms each MAG3 and DTPA) were studied, together, with a reference group of 10 patients in whom MAG3 and Hippuran clearance rates were determined simultaneously. As expected, 99mTc-MAG3 analog images were excellent and 99mTcMAG3 clearance correlated very well with 131I-hippuran clearance (r = 0.978). MAG3 values were 60% of hippuran values. However, when the corresponding renographic and perfusion findings were faced with different diagnostic challenges, such as post transplant renal failure and rejection, 99mTc MAG3 did not differ from 99mTc-DTPA in a significant way. 99mTc-DTPA was superior to 99mtc-MAG3 in one case of rejection.

Adult↗