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Biomedical subjects

A Ribeiro

Publications and source records attributed to A Ribeiro.

At least 37 records · Page 2Linked to original sources

The biological effects induced in mice by p36, a proteinaceous factor of virulence produced by African swine fever virus, are mediated by interleukin-4 and also to a lesser extent by interleukin-10.

We have previously presented indirect evidence that both specific immunosuppression and lymphocyte mitogenicity induced in mice by p36, a proteinaceous factor of virulence produced by porcine monocytes infected by African swine fever virus, were consistent with a Th2-driven response. Here we show: (1) Interleukin-4 (IL-4) and interleukin-10 (IL-10) mRNA expression in the spleen and thymus of C57BL/6 mice were displayed early after p36 inoculation. The expression of thymic IL-10 mRNA occurred, however, later than that of IL-4 mRNA. (2) Increased serum levels of these two cytokines were also soon detected after the protein inoculation. (3) Both immunosuppressive and mitogenic effects of p36 were absent in IL-4 gene-targeted mice and partially abrogated in mice depleted of IL-4 by neutralizing monoclonal antibodies. (4) IL-10 depletion abrogated the immunosuppressive but not the p36 lymphocyte mitogenic biological effects. (5) The increase in the serum concentrations of both IL-4 and IL-10 were lower in thymectomized than in non-thymectomized mice. (6) The expression of interferon-gamma (IFN-gamma) mRNA was weakly or not at all induced in p36-treated mice. Taken together, these results are in agreement with the promotion of a Th2 immune response induced by p36.

African Swine Fever Virus↗

Pulmonary embolism: a follow-up study of the relation between the degree of right ventricle overload and the extent of perfusion defects.

OBJECTIVES: To describe the course of changes in perfusion lung scintigraphy (LS) after acute pulmonary embolism (PE) and test the hypothesis that patients with persistent pulmonary hypertension (PH)/right ventricle (RV) dysfunction after acute PE can be differentiated from those without through larger perfusion defects (PDf) on LS. Design. Prospective, one-year follow-up study with repeated LS and echocardiography-Doppler investigations. SETTING: Single centre, University Hospital. SUBJECTS: Patients with clinical suspicion of acute PE with a diagnosis confirmed by LS and/or pulmonary angiography and able to undergo repeated investigations. Of the 78 patients included, a six-week follow-up was completed in 67 and a one-year follow-up in 64. MAIN OUTCOME MEASURES: Time course of PDf in relation to time course of pulmonary artery systolic pressure (PAsP) and RV function. RESULTS: Initially, PDf decreased exponentially, until the beginning of a stable phase, which was achieved within 54 days for 90% of the patients and within 148 days for all. The temporal relation for the regress of PDf and decrease in PAsP was loose. Patients with persistent PDf suffered PH/RV dysfunction more often than those without. However, the variability in the degree of haemodynamic changes for a given extent of PDf was large. CONCLUSIONS: After acute PE, LS is of use for the identification of the group of patients that may have persistent PH/RV dysfunction. However. since the identification of individual patients is uncertain, LS cannot replace echocardiography-Doppler in the identification of persistent PH/RV dysfunction after acute PE.

Acute Disease↗

Hodgkin's disease of the esophagus: report of a case.

Most esophageal malignancies are either squamous carcinomas or adenocarcinomas arising in the background of Barrett's esophagus. We describe a case of an 85-yr-old woman in whom the diagnosis of esophageal malignancy was difficult to confirm despite its endoscopic appearance and previous biopsies. This case illustrates the difficulty in diagnosing Hodgkin's disease of the esophagus. Despite the rarity of this entity, if clinically indicated by symptoms, large, deep biopsies by rigid esophagoscopy should be considered.

Aged↗

Non-coronary sinus of Valsalva aneurysm diagnosed after a road traffic accident.

A 38 year old man with a huge unruptured sinus of Valsalva aneurysm, complicated with severe valvar aortic regurgitation, is described. The aneurysm was detected by echocardiography in the asymptomatic patient who presented with an intense precordial diastolic rumble after a road traffic accident. The patient had successful surgery for the aneurysm and aortic valve replacement. Possible aetiologies for the aneurysm and a brief revision of clinical aspects and treatment are discussed.

Accidents, Traffic↗

[Myocardial infarct without angiographic coronary atherosclerosis: study of a group of patients].

STUDY OBJECTIVES: Clinical characterization and aspects of subsidiary clinical tests in a group of patients with myocardial infarction with no visible angiographic atherosclerotic stenosis. Etiologic identification, therapeutic approach and prognostic assessment of non atherosclerotic myocardial infarction. PATIENTS: We studied patients admitted with myocardial infarction to coronary care unit over a 4 year period and in whom cardiac catheterism did not show atherosclerotic coronary stenosis (17 patients). METHODOLOGY: Retrospective study; Assessment of clinical characteristics, exercise test parameters, echocardiogram, hemodynamics, heart rate variability (HRV) and signal-averaged electrocardiogram (ECG) of this group of patients; Maximal follow-up of 44 months and minimal of 3 months (average: 19.9 +/- 12.7 months) for the occurrence of ischemic cardiac events (recurrent angina, reinfarction or sudden death). RESULTS: Non atherosclerotic coronary infarction was an unusual situation (2% of the totality of the infarction hospitalized during those 4 years--795 cases), occurring mainly among young men, with few vascular risk factors (except smoking), as small infarctions, without a preferential localization and with good evolution in the acute phase (Killip I). In the predischarge exercise test there was no residual ischemia and functional capacity was generally good. In the majority of cases left ventricular systolic function was preserved (82% of the cases). With cardiac catheterism, we observed two cases of "bridging" and four cases of slow contrast progression. In arrhythmic risk stratification with 24 hours ECG, HRV and high resolution ECG, we observed no adverse prognostic markers in the majority of the cases. The clinical observation of the patients and the tests permitted us to establish probable hypotheses for the etiological diagnoses in 10 of the cases (left main anterior descending artery "bridging"--2 cases; slow contrast progression in the coronary vessels--4 cases, severe aortic stenosis--1 case; left valvular mechanic prosthesis--1 case: probable coronary thrombosis with complete reperfusion after thrombolytic therapy--2 cases). The therapeutic approach in the acute phase was the same as that of atherosclerotic infarctions. Secondary prevention was individualized and according to each case etiology, maintaining the antiplatelet agents. In the follow-up there was unstable angina in 3 patients. There were no cases of reinfarction or sudden death. CONCLUSIONS: This study allowed the characterization of the group of non atherosclerotic myocardial infarction as a group of young men with few vascular risk factors, with small infarctions and good prognosis, without adverse arrhythmic risk markers. It also allowed to identify the probable infarction etiology in 10 patients and the secondary individual prevention for each situation. We noted a good prognosis of this situation at two years.

Adult↗

[Pulmonary thromboembolism in a female with resistance to activated protein C].

Primary or acquired hypercoagulable states favour thrombotic events. The identification of prothrombotic states is of immediate practical usefulness in the orientation, prophylaxis and treatment of pulmonary embolism. Detection of individuals resistant to activated protein C. the most frequent laboratory anomaly in the study of patients with venous thromboembolism, offers a better approach for these patients as well as a better prophylaxis and orientation of their direct relatives concerning thromboembolic events. The authors describe the clinical case of a young woman, previously healthy, who developed serious pulmonary thromboembolism, the resolution of which was difficult and the evolution unusual. Later, a state of resistance to activated protein C (aPCr) was identified. Concerning the case described, the authors reflect on hypercoagulable situations, especially "aPCr" states.

Activated Protein C Resistance↗

Management of liver adenomatosis: results with a conservative surgical approach.

Liver adenomatosis is defined by the presence of multiple hepatic adenomas (more than three lesions). The natural history and treatment of liver adenomatosis are not yet well defined. The Mayo Clinic (Rochester, MN) experience with liver adenomatosis in the past 11 years was reviewed and a rational treatment approach is presented. Records from patients with liver adenomatosis and hepatic adenoma seen at the Mayo Clinic from January 1986 to June 1997 were reviewed. Estrogen- and progesterone-receptor status was assessed by immunohistochemistry. Eight women with liver adenomatosis were identified. All patients had undergone surgical treatment. Abdominal pain was the presenting symptom in 87.5% of the patients with adenomatosis and in 42.1% of the patients with hepatic adenoma. Tumor bleeding was present in 62.5% of the patients with adenomatosis and in 26.3% of the patients with hepatic adenomas. Bleeding occurred predominantly in lesions greater than 4 cm. All patients with liver adenomatosis reported improvement of symptoms after surgery, and the mean bleeding-free period after resection in 5 patients was 52.6 +/- 23.6 months. In 6 patients, estrogen receptor-positive and estrogen receptor-negative tumors were identified in the same liver. Based on the good outcome after resection in symptomatic patients with liver adenomatosis, we recommend resection of large (>/=5 cm) or symptomatic lesions with observation of smaller lesions (</=3 cm). Lack of estrogen receptors in many lesions suggests that estrogen does not play a dominant role in the pathogenesis of liver adenomatosis.

Adenoma, Liver Cell↗

Pulmonary embolism: relation between the degree of right ventricle overload and the extent of perfusion defects.

BACKGROUND: Inasmuch as the presence of right ventricle (RV) overload in patients with pulmonary embolism (PE) is associated with a bad prognosis, evaluation of RV function in PE is of importance. This study was done to establish if the degree of RV overload can be predicted from the extent of perfusion defects (PDf). METHODS: One hundred twenty-one consecutive patients with PE diagnosed by lung scintigraphy (LS) were examined by echocardiography Doppler (ED) immediately after diagnosis. PDf were graded visually in categories (LS score 1 = < or =20%, 2 = >20% of total lung area) and on a continuous scale (normal perfusion = 0, no perfusion = 1). The reproducibility of both methods was tested. RV wall motion was assessed on a four-point scale (0 = normal to 3 = severely hypokinetic). The distance from LV posterior wall to RV anterior wall and dimensions of RV and LV were measured. Pulmonary artery systolic pressure (PAsP) was calculated by using the maximum velocity of tricuspid regurgitation. RESULTS: There were 51 patients with LS score 1 and 70 (58%) with score 2. In comparison with patients with LS score 1, those with score 2 more often had RV hypokinesis 2+ or 3+ (n = 49 vs n = 16) (p < 0.001), larger RV (34 +/- 6 mm [22 to 48] vs 29 +/- 5 [17 to 38]) (SD [range]) (p < 0.001) and higher PAsP (51 +/- 13 mm Hg [21 to 83] vs 42 +/- 14 [20 to 81]) (p < 0.001). The variability in both groups was large. With continuous scaling, PDf averaged 0.3. This was also the value that best discriminated RV hypokinesis 2+ or 3+ in a receiver operating characteristic curve. However, the variability for this scan scoring method was SD 0.073, giving a 95% confidence limit of +/-0.15. CONCLUSION: There is a significant correlation between RV overload and PDf, but the variability is large; therefore, an estimate of the size of perfusion defects in LS cannot replace ED in the assessment of PAsP and the degree of RV overload in PE.

Aged↗

Colonic strictures induced by nonsteroidal anti-inflammatory drugs.

Long-term use of nonsteroidal anti-inflammatory drugs has been reported to cause small bowel and colonic ulcerations and strictures. Abdominal pain, change in bowel habits, and anemia are frequently present, mimicking other inflammatory and neoplastic diseases of the gut. We report two cases of drug-induced colonic stricture that illustrate two different spectrums of this disease. The first is a case of ascending colon ulcerated strictures and severe anemia managed conservatively, and the second is a chronic variant with obstructive-type symptoms and a tight nonulcerated colonic stricture that necessitated right hemicolectomy.

Aged↗

[Differential imaging diagnosis of left ventricular aneurysm and pseudoaneurysm in the course of a myocardial infarct].

Differential diagnosis between true and false left ventricular aneurysms is not always easy, despite the use of imaging techniques of great diagnostic accuracy. We report a case in which the distinction between these two situations offers some difficulty. Finally, we review the characteristics of ventricular aneurysms and that of pseudoaneurysms, focusing on the aspects that enable their differentiation.

Aneurysm, False↗

[Anomalous origin of the left pulmonary artery (Sling): a case report and review of the literature].

Anomalous left pulmonary artery (vascular sling) is a congenital anomaly in which the vascular structure arises either from the posterior surface of the right pulmonary artery, or from the main pulmonary artery and courses to the left lung between the posterior surface of the trachea and the anterior surface of the esophagus. It may cause compression on the tracheobronchial tree. It is a rare condition leading to death in the first months of life, if it is not corrected. Its diagnosis is quite difficult because it usually presents non specific symptoms frequently associated to diffuse tracheal stenosis. The authors present a clinical case of a newborn with trisomy 21 who had a left pulmonary artery sling associated to tracheal stenosis and congenital heart disease (complete atrioventricular septal defect). They review the literature, particular in what concerns embryopathogenesis, the difficulties in establishing the diagnosis and the surgery which must be performed as soon as possible.

Aortopulmonary Septal Defect↗

Echocardiography Doppler in pulmonary embolism: right ventricular dysfunction as a predictor of mortality rate.

To test the hypothesis that right ventricular (RV) systolic dysfunction at the time of diagnosis of pulmonary embolism (PE) is a predictor of mortality rate, 126 consecutive patients with PE were examined with echocardiography Doppler (ED) on the day of diagnosis. RV function was assessed by evaluation of wall motion on a four-point scale. The material was divided into two groups: group A (n = 56) with normal or slightly reduced RV function and group B (n = 70) with moderately or severely reduced RV function. The overall mortality rate was 7.9% in the hospital and 15.1% within 1 year. Four deaths occurred in group A and 15 in group B (p = 0.04). All in-hospital deaths (n = 10) occurred in group B (p = 0.002). The variables associated with mortality rate were RV dysfunction and cancer (in-hospital, p = 0.002 and 0.004; 1 year, p = 0.04 and < 0.001, respectively). Nine (7.1%) deaths (all in-hospital) were caused by PE. Five of these patients had advanced-stage cancer. The in-hospital mortality rate in patients without cancer was 4%, all from PE and all in group B. In conclusion, RV dysfunction when diagnosis of PE is established is associated with mortality rate. A strategy for risk stratification of patients with PE with ED may be of clinical usefulness.

Aged↗

Laparoscopic evaluation of liver disease in chronic renal failure prior to renal transplantation.

BACKGROUND: Diagnostic laparoscopy with liver biopsy has been shown to be safe and effective in the evaluation of patients with chronic liver disease. Patients with end-stage renal disease may be more prone to bleeding complications secondary to liver biopsy as a result of multiple factors directly related to their underlying renal condition. METHODS AND PATIENTS: From January 1994 to June 1996, 16 patients with end-stage renal disease and hepatic dysfunction (6 women and 10 men) underwent diagnostic laparoscopy with liver biopsy prior to renal transplantation at the University of Miami School of Medicine. Laparoscopy was performed using a 5 mm video laparoscope with a left paramedian approach. The mean patient age was 46 years. Fourteen patients had chronic hepatitis C with a reactive anti-HCV by ELISA; one patient had chronic hepatitis B with reactive HBsAg, and one patient was co-infected with both hepatitis B and C viruses. RESULTS: Two patients developed hypotension related to the procedure and one patient developed an intra-abdominal hemorrhage 5 days after laparoscopy that did not require surgical intervention. Biopsy findings were as follows: 13 patients had mild chronic hepatitis; 2 patients had chronic hepatitis with bridging fibrosis; and 1 patient was cirrhotic. Prior kidney transplantation or peritoneal dialysis did not preclude the performance of laparoscopy. CONCLUSION: Diagnostic laparoscopy can be safety performed in patients with end-stage renal disease with acceptable morbidity and mortality.

Abdomen↗

Trypanocidal flavonoids from Trixis vauthieri.

The crude extract of Trixis vauthieri (Asteraceae) was active against the trypomastigote forms of Trypanosoma cruzi, the protozoan that causes Chagas' disease. Bioassay-guided fractionation of this extract afforded the trypanocidal flavonoids 5,4'-dihydroxy-7-methoxyflavanone (1) and 5,4'-dihydroxy-3,6,7-trimethoxyflavone (2) besides the inactive flavonoids 3,5,4'-trihydroxy-7-methoxyflavanone (3) and 5,4'-dihydroxy-3,6,7,8-tetramethoxy flavone (4). The trypanocidal activity of 1 and 2 and the presence of compounds 2 and 4 in Trixis vauthieri are reported here for the first time.

Animals↗

The addition of mibefradil to chronic hydrochlorothiazide therapy in hypertensive patients is associated with a significant antihypertensive effect.

OBJECTIVE: To evaluate the antihypertensive efficacy, tolerability, safety, and dose-response characteristics of the novel calcium antagonist, mibefradil, in combination with a diuretic regimen. DESIGN: A multinational, double-blind, randomised, placebo-controlled, parallel-design trial. METHODS: Three hundred and seven patients whose mild-to-moderate essential hypertension remained uncontrolled after 4 weeks of treatment with hydrochlorothiazide (HCTZ) 25 mg/day and placebo were randomised to receive combined treatment with HCTZ and once-daily doses of 12.5, 25, 50, or 100 mg of mibefradil or placebo. After 8 weeks of combined treatment, HCTZ was withdrawn and the mibefradil groups continued on their respective doses for an additional 6 weeks. RESULTS: After 8 weeks, the addition of once-daily doses of mibefradil to the initial HCTZ regimen resulted in clinically relevant, dose-related reductions in sitting diastolic blood pressure (SDBP) and sitting systolic blood pressure (SSBP) at trough, which were significantly greater in the 50 and 100 mg dose groups compared to the placebo group (P < or = 0.003). Placebo-corrected treatment effects on SDBP and SSBP at the end of the combined treatment period relative to baseline were, respectively, -4.1 and -8.0 mm Hg in the 50 mg mibefradil group and -9.5 and -8.0 mm Hg in the 100 mg mibefradil group. Therapeutic response rates to combination mibefradil and HCTZ therapy were high and dose related, reaching 82% for SDBP in the 100 mg group. CONCLUSIONS: The addition of once-daily doses of 50 or 100 mg of mibefradil to patients whose hypertension is not controlled by HCTZ alone is well tolerated and effective in improving BP control.

Adult↗