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Biomedical subjects

G Del Negro

Publications and source records attributed to G Del Negro.

17 recordsLinked to original sources

Extended vertical transseptal approach versus conventional left atriotomy for mitral valve surgery.

BACKGROUND AND AIM OF THE STUDY: Mitral valve surgery requires optimal exposure of the valvular apparatus, particularly when a conservative procedure is used. Retrospectively, we compared surgical results in patients who underwent mitral valve surgery using the vertical transseptal approach (which has been adopted routinely in our institute) with those in patients undergoing conventional left atriotomy. METHODS: A total of 172 consecutive patients operated on for mitral procedures were allocated to either group A (those operated on through a longitudinal left atriotomy; n = 62), or group B (mitral valve exposure achieved through an extensive vertical transseptal approach; n = 110). RESULTS: In group A, there were 24 valvular reconstructions and 38 valvular replacements. Mean (+/- SD) cardiopulmonary bypass (CPB) time was 65.9 +/- 17 min and mean ischemia time 37.4 +/- 13 min. Total postoperative bleeding was 277 +/- 171 ml. There was no surgical re-exploration for bleeding. One patient in this group died (mortality rate 2%). Among 40 patients in atrial fibrillation preoperatively, four had one episode of temporary junctional rhythm, six had temporary sinus rhythm and two had stable sinus rhythm. Among patients with preoperative sinus rhythm, six (27%) had episodes of atrial fibrillation and two (9%) temporary atrioventricular block. In group B, 46 mitral reconstructions and 64 mitral replacements were performed. Mean CPB time was 67.9 +/- 20 min and mean ischemia time 48.1 +/- 17 min. Total postoperative bleeding was 400 +/- 189 ml. Three patients in this group died (mortality rate 2.7%). Among 60 patients with preoperative atrial fibrillation, six (10%) had one episode of temporary junctional rhythm, 14 (24%) had temporary sinus rhythm and two (3%) had conversion to stable sinus rhythm. Among those in sinus rhythm preoperatively, 16 (32%) had episodes of temporary junctional rhythm, two (4%) had temporary atrial fibrillations, and four (8%) had stable atrial fibrillation. In group B patients, the incidences of ischemia time and total postoperative bleeding (p = 0.004), and postoperative junctional arrhythmia in those with preoperative sinus rhythm (p < 0.001), were greater than in group A patients. CONCLUSIONS: No technique-related deaths occurred; neither were causes of re-exploration for bleeding related to technique, and there was no evidence of residual interatrial shunt. In conclusion, transseptal extended atriotomy provides excellent exposure for mitral valve surgery. Disadvantages of minimally increased ischemia time and surgical bleeding are minor compared with the superior and more complete surgical reconstruction achieved. The advantages of the technique are undermined by the higher incidence of junctional arrhythmia which, even if temporary, requires strict postoperative monitoring.

Cardiopulmonary Bypass↗

One leaflet immobilization after mitral valve replacement with a bileaflet prosthesis.

We report four cases of one leaflet immobilization which occurred early after mitral valve replacement with a Carbomedics bileaflet valve. The first case was diagnosed incidentally six days after surgery and did not require reoperation because of the spontaneous normalization of the valve movements the day before the scheduled reoperation. Since then, we have been using intraoperative transesophageal echocardiography in mitral procedures routinely (both valve repair or replacement). We were able to detect malfunctions which required reorientation in three other prostheses. We emphasize the importance of performing intraoperative transesophageal echocardiography routinely in these procedures; its high sensitivity and low risk can help to avoid a late reoperation.

Echocardiography, Doppler↗

Activation of human complement system in paracoccidioidomycosis.

Plasma samples of 14 patients with paracoccidioidomycosis were analysed for components that represent activation of the complement system. Most patients (12/13) showed significant titres of complement-fixing antibodies and 14/14 had increased C4d/C4 ratios. There was no conclusive correlation between these two immunological indices, however. Factor B values of patients were similar to normal donors and fragment Ba was not detected in any of the patients. These results indicate a classical complement pathway activation in the plasma of patients with paracoccidioidomycosis.

Adolescent↗

Gallium-67 imaging in the diagnosis of blastomycosis.

67Ga imaging was used in a group of 13 untreated patients with documented South American blastomycosis in an attempt to obtain additional information on the site and extent of the lesions. All diagnoses were confirmed by demonstration of the fungi in the lesions or body fluids. Serologic tests were performed on all patients. 67Ga imaging was correlated with X-ray in all patients, and with bone imaging when bony lesions were suspected. 67Ga imaging was positive for all lesions detected on chest X-ray and by clinical evaluation. More importantly, lesions clinically unsuspected and missed by other diagnostic techniques were shown on 67Ga imaging: bony and hepatic lesions in three patients; a brain lesion in one patient and parotid gland involvement in five patients. There was good agreement between 67Ga imaging and clinical and laboratory data, scintigraphy being more sensitive. Follow-up studies after specific therapy demonstrated decreased uptake in the lungs and other sites. 67Ga imaging is a useful tool for detection of suspected and unsuspected lesions of blastomycosis and to evaluate the response of the disease to specific therapy.

Adult↗

Primary cutaneous cryptococcosis.

A 7-year-old boy, without apparent underlying disease, but with a non-specific failure in his cellular immunity, developed a cutaneous lesion on the left retroauricular area with spontaneous healing. Mycologic study revealed Cryptococcus neoformans, a capsule deficient strain, as the etiologic agent.

Child↗

Limited adrenal reserve in paracoccidioidomycosis: cortisol and aldosterone responses to 1-24 ACTH.

Adrenal function in twenty-three patients with paracoccidioidomycosis (South American Blastomycosis) has been assessed by measuring the response to adrenocortical stimulation with 1-24 ACTH. Two patients with overt Addison's disease showed very low basal levels and the complete absence of an increase in either cortisol or aldosterone secretion. Six patients showed probable diminished adrenal reserve in terms of cortisol and three patients showed diminished reserve in terms of aldosterone function. These findings indicate an incidence of significant hypoadrenalism in 44% of hospitalized patients with disseminated paracoccidioidomycosis.

Adolescent↗

Thrombocytopenia and leptospirosis.

The present study has intended to contribute to the elucidation of the pathogenic mechanisms, involved in the thrombocytopenia and in the bleeding diathesis seen in the course of Leptospirosis. The group of cases included in the present prospective study consisted of 30 patients with Leptospirosis, admitted to the Infectious and Parasitic Diseases Ward, Hospital das Clínicas, Faculty of Medicine, University of São Paulo. The following possible mechanisms of thrombocytopenia have been considered and therefore investigated: platelet consumption, due to disseminated intravascular coagulation; immune-mediated platelet destruction, due to platelet-associated antibodies and an inhibited platelet production in the bone marrow. Thrombocytopenia occurred in 86.6% of 30 patients and did not seem to be immune-mediated by platelet-associated antibodies. Furthermore it did not seem to be due to a disseminated intravascular coagulation consumption. Although there was a statistically-significant correlation between bone marrow platelet production and platelet counts we think that the static microscopic examination of a bone marrow aspirate cannot accurately depict the dynamic mechanisms of platelet production when these cells are being consumed in peripheral blood. Vasculitis should be considered as the most important factor for the pathogenesis of the bleeding disturbances in Leptospirosis. However, we believe that thrombocytopenia, uremia and coagulation disorders, individually or as a group, should be included among the contributing factors that lead to and worsen bleeding episodes, which represent the leading cause of death in this disease.

Antibodies↗

[Bone marrow involvement and eosinophilia in paracoccidioidomycosis].

The authors described three acute paracoccidioidomycosis patients with bone marrow involvement. P. brasiliensis yeast forms were observed in bone marrow smears of all them, and in one case, culture also revealed fungus growth. The mononuclear phagocytic system involvement, the blood eosinophilia and the negative skin hypersensibility responses were emphasized in all of them, as well as the severity of the disease in one case, with disseminated bone lesions and 20.260 eosinophils/mm3 in peripheral blood. The authors discuss the possible role of eosinophil in the host-parasite interaction in paracoccidioidomycosis, suggesting that TH 2 subpopulation activation and increased IL 5 and GM-CSF secretions may be responsible by eosinophilia in the most severe case.

Acute Disease↗