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Biomedical subjects

N Stolf

Publications and source records attributed to N Stolf.

At least 37 records · Page 2Linked to original sources
PubMed1995

Autoimmunity in Chagas disease cardiopathy: biological relevance of a cardiac myosin-specific epitope crossreactive to an immunodominant Trypanosoma cruzi antigen.

Heart tissue destruction in chronic Chagas disease cardiopathy (CCC) may be caused by autoimmune recognition of heart tissue by a mononuclear cell infiltrate decades after Trypanosoma cruzi infection. Indirect evidence suggests that there is antigenic crossreactivity between T. cruzi and heart tissue. As there is evidence for immune recognition of cardiac myosin in CCC, we searched for a putative myosin-crossreactive T. cruzi antigen. T. cruzi lysate immunoblots were probed with anti-cardiac myosin heavy chain IgG antibodies (AMA) affinity-purified from CCC or asymptomatic Chagas disease patient-seropositive sera. A 140/116-kDa doublet was predominantly recognized by AMA from CCC sera. Further, recombinant T. cruzi protein B13--whose native protein is also a 140- and 116-kDa double band--was identified by crossreactive AMA. Among 28 sera tested in a dot-blot assay, AMA from 100% of CCC sera but only 14% of the asymptomatic Chagas disease sera recognized B13 protein (P = 2.3 x 10(-6)). Sequence homology to B13 protein was found at positions 8-13 and 1442-1447 of human cardiac myosin heavy chain. Competitive ELISA assays that used the correspondent myosin synthetic peptides to inhibit serum antibody binding to B13 protein identified the heart-specific AAALDK (1442-1447) sequence of human cardiac myosin heavy chain and the homologous AAAGDK B13 sequence as the respective crossreactive epitopes. The recognition of a heart-specific T. cruzi crossreactive epitope, in strong association with the presence of chronic heart lesions, suggests the involvement of crossreactivity between cardiac myosin and B13 in the pathogenesis of CCC.

Amino Acid Sequence↗
PubMed1995

[Infections in 100 heart transplantation patients].

PURPOSE: A prospective study of infective agents in diagnosed infections and deaths by specific agents in cardiac transplant patients. METHODS: Infections occurring in a series of 100 consecutive cardiac transplant patients after transplantation with definite infectious diagnosis were studied; follow-up after transplantation was 3 to 90 (medium 25.38 +/- 25.97) months. Diagnostic criteria for defining infections were those used in the Epidemiology and Quality Control Division of the INCOR, that are the same published by the Centers for Disease Control. The following parameters were analysed: infections/patient/time, causes of infection and organs infected, clinical presentation and clinical aspects of infections, methods used for the infective diagnosis and relationship between rejection episodes and infection. Death caused by infections and survival rates per infection were also studied. RESULTS: Bacterial infections were more frequent (56.3% of all infections), followed by viral infections (19.6%), fungal infections (18%) and protozoal infections (6.1%). Of all deaths after transplantation, 25% were caused by infections. CONCLUSION: Infections are an important cause of mortality and morbidity in this patient population; our data are in accordance to the other reported series.

Actuarial Analysis↗
PubMed1994

Restricted heterogeneity of T cell receptor variable alpha chain transcripts in hearts of Chagas' disease cardiomyopathy patients.

The role of autoimmunity in the pathogenesis and progression of heart lesions in the chronic phase of Chagas' disease is controversial. In the absence of parasites in situ, the T cell infiltrate seen in heart lesions may be the primary determinant of tissue damage ultimately leading to heart failure and death. We used the polymerase chain reaction to amplify each known T cell receptor (TCR) V alpha and V beta subfamily-specific sequence in transcripts derived from heart samples obtained from Chagas' cardiomyopathy patients. The average number of TCR V alpha subfamilies (7.1 per tissue sample) was significantly lower than that for TCR V beta subfamilies (15.1 per sample). The average percentage of tissue samples positive per TCR V alpha and V beta subfamily was respectively 39.6% vs. 73.5%. These data suggest that, in Chagas' heart lesions, the detectable TCR V alpha repertoire is significantly narrower than TCR V beta repertoire. On the other hand, in normal heart tissue, diversity of V alpha and V beta TCR is similar among the scarce circulating T cell population. Such evidence of restricted TCR V region repertoire has been described in experimental and human autoimmune diseases. Our results are consistent with the possibility that T cells responsible for heart damage in chronic Chagas' cardiomyopathy may be recognizing a few heart-specific antigenic targets.

Base Sequence↗
PubMed1994

[Lipoprotein (a), apolipoproteins and the lipid profile late after heart transplantation].

PURPOSE--To evaluate if the levels of lipoprotein (a) [Lp(a)], apolipoproteins (apo) A1, B and the lipid profile (LP) differ among heart transplantation (HT) patients, with coronary artery disease (CAD) and patients without CAD (NL) and if LP discriminates patients with graft vascular disease (GVD). METHODS--A hundred and seventy patients separated in 3 groups: I) HT [n = 43 46 +/- 15 years, 24 months (median) after transplantation], of these 28 were submitted to serial angiography after the first year of transplantation subgroups with GVD (n = 9) and without GVD (NGVD) (n = 19); II) CAD (n = 72, 48 +/- 6 years); III) NL (n = 45, 50 +/- 6 years). RESULTS--HT presented higher apo A1 levels than CAD and NL (1.5 +/- 0.5 vs 1.2 +/- 0.05 vs 1.1 +/- 0.06 g/l p < 0.05 respectively). Apo B was higher on CAD than in HT and NL (1.5 +/- 0.05 vs 1.2 +/- 0.07 vs 1.3 +/- 0.09 g/l p < 0.05). Lp (a) presented a trend to higher levels in HT and CAD than in NL [25(2-97), 24(1-130) and 15 (1-100) mg/dl, p = 0.05)]. However, when individually evaluated against NL Lp(a) levels were higher in HT and CAD (p = 0.019 and 0.03 respectively). LP did not differ between GVD and NGVD. CONCLUSION--Increased Lp(a) levels after transplantation might be related to the high prevalence of GVD. The LP did not discriminate GVD.

Adult↗
PubMed1994

[Hemodynamic evaluation during isotonic exercise of patients with orthotopic heart transplantation].

PURPOSE: To evaluate the hemodynamic response of patients submitted to orthotopic heart transplantation during progressive isotonic exercise. METHODS: Eight patients who underwent orthotopic heart transplantation have been evaluated through invasive hemodynamic study during isotonic exercise. The mean right atrial pressure (RAP), pulmonary artery pressure (PAP), pulmonary artery wedge pressure (PAWP), arterial blood pressure (ABP), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), heart rate (HR) and cardiac output (CO) have been determined in three distinct situations: at rest in the supine position (R), at rest with the legs up (RU) and during progressive isotonic exercise (E). The hemodynamic results at rest have been compared to the ones before transplantation. Phase RU and E results have been compared with each other. RESULTS: Comparing to the phase before transplantation at the R phase we found normalization of mean PAP (34.9 +/- 14.0 to 17.0 +/- 3.5 mmHg), RAP (7.3 +/- 4.3 to 2.9 +/- 1.9 mmHg) and CO (2.9 +/- 0.98 to 5.7 +/- 0.99 l/min), otherwise there was an increase in HR (89 +/- 15 to 94 +/- 13 bpm) mean ABP (84 +/- 25 to 115 +/- 12 mmH) and SVR (30 +/- 15 to 22 +/- 7 units Wood), (p < 0.05). Comparing phase E to phase RU, there was a significant increase in RAP (3.1 +/- 1.8 to 9.4 +/- 3.9 mmHg), mean PAP (21.0 +/- 2.8 to 37.0 +/- 10.0 mmHg), PAWP (8.1 +/- 2.1 to 15.0 +/- 5.8 mmHg), CO (5.8 +/- 0.8 to 9.9 +/- 2.4 l/min), HR (93 +/- 8 to 116 +/- 18 bpm) and a decrease in SVR (22.0 +/- 3.0 to 13.3 +/- 3.8 units Wood), (p < 0.05), otherwise there was no statistically significant modifications in PVR (2.2 +/- 0.7 to 2.3 +/- 1.2 units Wood) and mean ABP (129 +/- 12 to 129 +/- 15 mmHg), (p = NS). CONCLUSION: Patients submitted to heart transplantation may improve cardiac output mainly from increasing in stroke volume, associated with an increase in RAP and PAP. Nevertheless, the improvement increase in CO is compatible to exercise capacity after heart transplantation.

Adult↗
PubMed1994

[Percutaneous transluminal coronary angioplasty after orthotopic heart transplantation].

We report the case of 22 year-old male who developed coronary artery disease two years after orthotopic cardiac transplantation, manifested as congestive heart failure NYHA functional class III. The left ventricular radioisotopic evaluation at rest revealed worsening of left ventricular ejection fraction from 50% to 39% (normal value > or = 55%) and septal hypokinesia. The hemodynamic and coronariographic study showed two subocclusive lesions at the mid portion and distal portion of the left descending coronary artery and the patient underwent PTCA of both lesions, successfully reducing them to 30%. A new radionuclide and echocardiographic evaluation of left ventricular function at rest, showed marked improvement of global function no regional abnormalities, increasing the ejection fraction from 39% to 45%. The patient showed improvement of NYHA functional class, passing to functional class II and was discharged home. We conclude that PTCA could be performed in a successful manner in this patient.

Adult↗
PubMed1994

[Arrhythmias following orthotopic heart transplantation].

PURPOSE: To correlate the incidence of arrhythmias to the degree of allograft rejection on endomyocardial biopsy. METHODS: Seventeen patients who underwent orthotopic heart transplantation were submitted to ambulatory Holter monitoring 24h prior to endomyocardial biopsy. The biopsy results were compared to Holter monitoring results. RESULTS: The mean study period was 252 +/- 166 days (15 to 515). We found a high incidence of ventricular premature beats (> 70%), except in patients with severe rejection (25%), but there was no statistically significant difference between the groups with no rejection, mild and moderate rejection. Atrial premature beats were more common in patients with mild and moderate rejection (53% and 70%, respectively) when compared to patients with no rejection (33%) and patients with severe rejection (9%), (p < 0.05). Sinus bradycardia was present in 50% of patients with severe rejection, but only in 9% of moderate, 3% of mild and 5% of the patients with no rejection (p < 0.05). CONCLUSION: Supraventricular tachycardia and atrial premature beats are related to moderate rejection. Ventricular premature beats are not related to degree of rejection. Sinus bradycardia occurring in the first year after transplantation should suggest severe cardiac allograft rejection.

Arrhythmias, Cardiac↗
PubMed1994

[Hemodynamic and neurohormonal profile during assisted circulation with heterotopic artificial ventricle followed by heart transplantation].

We describe the hemodynamic and neurohormonal data during ventricular assistance device system support as a bridge to heart transplantation of one patient, 30 years old, with heart failure due to Chagas' heart disease in functional class IV. We determined the pressures in mmHg of right atrium (RA), pulmonary artery pressure (PAP), pulmonary wedge pressure (WEDGE), arterial blood pressure (AP), and the cardiac output (CO) in l/min. In addition, the blood levels of norepinephrine (Ne), renin (Re), epinephrine (Ep), lactate and the mixed venous oxygen pressure (pVO2) were determined. The CO increased from 2.14 to 3.9-4.2 l/min, the AD decreased from 26mmHg to 8mmHg, the MPAP reduced from 38mmHg to 14-24mmHg, the WEDGE reduced from 25 to 4mmHg and the AP become normal. The Ne reduced from 1927pg/ml to 983pg/ml, the lactate reduced from 99mg/dl to 22mg/dl and the pVO2 increased from 28mmHg to 43mmHg. The EP remained between 81pg/ml and 129pg/ml, the renin activity remained between 113ng/ml/hr and 136ng/ml/hr. Thus, during the ventricular assistance device system support there was a improvement in hemodynamic and neurohormonal conditions. The patient underwent successful heart transplantation.

Adult↗
PubMed1992

[Acute aortic dissections. Hospital outcome of 186 cases].

PURPOSE: To determine in hospital outcome acute aortic dissection patients. METHODS: We revised 186 consecutive cases (up to 14 days of dissection), in a period of 6 years. The patients were divided according to Daily's classification (types A and B). RESULTS: Type A--127 cases: a) 75 were surgically treated (37 died); b) 2 were medically treated (both died); c) 39 died before the definitive treatment could be initiated; d) 11 died misdiagnosed or undiagnosed. The total mortality was 70.0%. Type B--59 cases: a) 11 complicated cases were surgically treated (6 died); b) 40 were medically treated (8 died); c) 7 died before the definitive treatment could be initiated; d) one died misdiagnosed. The total mortality was 37.25%. In summary, 41.4% of the patients survived. 28.4% died despite the definitive treatment, 24.7% died before the definitive treatment could be initiated and 6.4% died without the correct diagnosis. CONCLUSION: The acute aortic dissection is a dramatic situation, mainly type A. In this type of dissection many patients (41%) died misdiagnosed, undiagnosed or without enough time to surgical therapy. So, an earlier diagnosis and treatment are imperative.

Acute Disease↗
PubMed1991

Decrease in sulphated glycosaminoglycans in aortic dissection--possible role in the pathogenesis.

STUDY OBJECTIVE: The aim was to investigate alterations in sulphated glycosaminoglycans in aortic dissection. DESIGN: Aortic fragments were taken from 10 patients within the first 3 d after onset of symptoms of aortic dissection and from nine age matched patients with no aortic disease. Sulphated glycosaminoglycans were analysed and quantified by agarose gel electrophoresis and densitometry after degradation with specific enzymes. MEASUREMENTS AND MAIN RESULTS: The amount of chondroitin sulphate was similar (7.14 v 7.60 mg.g-1 of dry tissue, n = 10, p greater than 0.5) in patients with dissection and in the control group. Total sulphated glycosaminoglycan content was decreased (11.51 v 14.26 mg.g-1 of dry tissue, n = 10, p less than 0.001). This difference was due to heparan sulphate (1.79 v 2.48 mg.g-1 of dry tissue, n = 10, p less than 0.05) and mainly to dermatan sulphate (2.58 v 4.18 mg.g-1 of dry tissue, n = 10, p less than 0.001). The ratio of 6-/4-sulphated disaccharides after chondroitinase ABC digestion was increased in the affected group. No correlation between these biochemical results and a histological evaluation of mucoid content was found. On the other hand, a significant increase in chondroitin sulphate could be observed related to aging. CONCLUSIONS: The diminution in sulphated glycosaminoglycans and its possible relationship with fat, collagen, and other extracellular matrix molecules could lead to a weakness in the aortic wall related to the dissection.

Adult↗
PubMed1991

[Coronary angioplasty in a 12-year-old child].

Coronary artery disease is seldom reported in patients under 20 years of age. We present here the case of a 12 years old male, with systemic high blood pressure who had 2 episodes of typical chest pain. He underwent a submaximal exercise treadmill test which was negative. He then underwent cinecoronarography that revealed a 78% (measured by the caliper) obstruction in the proximal segment of the circumflex coronary artery with 3 mm of extension. The left coronary artery and the left ventricle were normal. The patient was subjected to a percutaneous transluminal coronary angioplasty, which was successful and left a 12% (measured by caliper) residual stenosis. The late angiographic restudy (5 months after the procedure) showed the maintenance of the immediate success of the procedure.

Angioplasty, Balloon, Coronary↗