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Biomedical subjects

M Valente

Publications and source records attributed to M Valente.

At least 253 records · Page 14Linked to original sources
PubMed1981

Pathological study of infective endocarditis on Hancock porcine bioprostheses.

A pathological study has been performed on 10 infected Hancock bioprostheses removed from nine patients who died of prosthetic endocarditis. The devices had been in place from 2 to 87 months (average 37.5), the interval between operation and onset of infection averaging 30 months. The offending organisms were Gram negative bacteria in three patients (Klebsiella pneumoniae, Enterobacter cloacae, and Serratia marcescens), Gram positive bacteria in two (Staphylococcus aureus and Streptococcus viridans), and fungi in four (Candida species in three and Aspergillus species in one). Gross examination of the explants revealed in most cases a vegetative endocarditis of one porcine valve leaflets. Septic embolization occurred in five cases owing to the high friability of the vegetations. Prosthetic valve incompetence was the commonest type to dysfunction observed because of tears, perforations, and even complete destruction of the cusps. Prosthetic valve stenosis following obstruction of the valve orifice by infected polypous masses was noted in two cases. Clumps of infective organisms were detected deep in the cusp tissue in most cases on histologic examination. Infection located on the paraprosthetic tissues, associated with ring abscess, valve detachment, and insufficiency, was observed only once. According to the results of investigation, endocarditis on porcine bioprostheses is associated with a better preserved native valvular ring as viewed at reoperation. Therefore surgical intervention appears appropriate in the presence of severe hemodynamic complications after adequate antibiotic treatment. However, infection of these particular prostheses still carries an extremely high mortality. In the present series, this poor outcome might be explained by the frequently associated septic and thromboembolic events.

Adult↗
PubMed1981

[Prajmalium bitartrate in hyperkinetic ventricular arrhythmias in infarct patients during rehabilitation].

The present study was designed to assess the antiarrhythmic Prajmalium Bitartrate (PB) efficacy in the long term treatment of 22 patients with recent myocardial infarction and persistent, frequent, polimorphous, repetitive (two or more in a row) ventricular premature complexes (VPCs). VPCs were exposed by means of 24-hours ambulatory monitoring. The acute drug testing with a single dose of PB (30 mg) was followed by multiple maintenance therapy with a dose decreasing from 60 to 40 mg every day. Than, the long term antiarrhythmic action was evaluated by both monitoring and exercise stress testing (EST), symptom self-limited, in a 7 months and 28 days follow-up. A favorable therapeutic effect, with a reduction of VPCs frequency greater than 85% and the suppression of their greater Lown degrees, was obtained in 13 cases (59.2%) using PB alone and in 6 cases (27.2%) using PB associated with Amiodarone in 5 patients and with Metoprololo in one. No VPCs were present or they were less than 2 every 3 minutes during EST. Fourteen patients reported a recurrence of VPCs when the drug was stopped for 24-28 hours, after 3-5 months of the treatment. In 3 patients (13.6%) the PB was uneffective. In a case there was, during the acute drug testing, a paradox increasing of the arrhythmias, and in the other two an abnormal lengthening of QTc interval, while arrhythmia was unchanged. PB, alone or associated with other antiarrhythmic drugs, appears a well tolerated, handy and effective agent and it can be proposed as a drug of first choice for controlling VPCs.

Adult↗
PubMed1980

Estrogen receptors and MPA treatment in metastatic renal carcinoma. A preliminary report.

Ten previously untreated patients with metastatic renal carcinoma underwent transperitoneal radical nephrectomy followed by high dosage MPA treatment. Estrogen receptors were determined in the specimen of all cases by the dextran-coated charcoal method: both the neoplastic tissue and the healthy parenchyma were tested. The disease progressed in 8 cases, and 2 patients are alive without any evidence of progressive disease 12 and 27 months after the operation. Very low receptor levels were detected in these 2 cases and one of them could be defined as borderline with our threshold criterion. However, receptors were undetectable in the neoplastic tissue from 4 of 8 patients who progressed. These questionable results justified the start of a prospective multicentric trial to study in a large number of cases both hormone receptors and clinical response to hormone therapy in human renal cancer.

Adult↗
PubMed1980

Screening of thalassaemia carriers in intermediate school of Latium: results of four years' work.

From 1975 to 1979 the Rome Microcythaemia Centre carried out four health education campaigns and thalassaemia screenings among students of the intermediate schools throughout Latium, under the auspices and with the financial support of the Health Authorities of the Latium region. This project is aimed at avoiding reproduction by pairs of thalassaemia carriers and the birth of homozygous children. During the four campaigns 138 501 students were examined, that is, 70 to 76% of those enrolled. Of these 3343 were found to be thalassaemic. Thus the overall prevalence of thalassaemia in Latium is 2.41%, with minor fluctuations from one province to another and, above all, a slight, though definite, trend towards higher values in the southern part of Latium bordering on Campania. The screening was welcomed by the population and the thalassaemic families, there were no detectable negative side-effects, and it resulted in an increased awareness of the problem of the thalassaemias.

Adolescent↗
PubMed1980

Histological survey of the saphenous vein before its use as autologous aortocoronary bypass graft.

A histological examination has been carried out on the saphenous veins used in 150 consecutive patients undergoing aortocoronary bypass. Morphological changes were observed frequently and consisted mainly of fibrosis of the intima and of the medial longitudinal muscular layer. Intimal fibrosis was rarely severe enough to narrow the lumen significantly. Statistical analysis disclosed that the fibrosis of the intima and the medial longitudinal muscular layer do not increase with age. The use of frozen histological sections of the saphenous vein in patients undergoing aortocoronary bypass operations could be considered in order to discard unsuitable grafts and to direct the surgeon to alternative conduits.

Coronary Artery Bypass↗
PubMed1980

Preoperative irradiation and surgery for esophageal cancer: causes of failure.

Twenty-seven patients with squamous esophageal cancer underwent small volume, low-dose, concentrated radiotherapy followed by esophageal resection whenever possible (esophagectomy for tumors of the thoracic esophagus and esophagogastrectomy for tumors of the lower esophagus). Curative resectability was 70% (19/27) with 4 operative deaths (21%). Recurrence rate was 66% after a mean period of 16 months, and the failure pathway was nodal in 53% of the cases. Historical comparison of the data suggests that preoperative irradiation increases the curative resectability rate without changing the early recurrence rate or failure pathway. Tumors with deeper invasion of the esophageal wall, which benefit by preoperative irradiation, are probably related to greater nodal diffusion, which is partly outside of the volume that may be resected or irradiated.

Adult↗
PubMed1980

[The acromegalic heart disease (author's transl)].

The clinical and pathological findings of 3 patients with acromegalic heart disease are reported. In 2 of them no other causes of the cardiopathy could be recognized but a primitive involvement of the myocardium. The GH is responsible of cardiac hypertrophy without overload, which would shift towards progressive congestive heart failure. A possible depletion of intramyocardial cathecolamines is postulated in acromegalic heart disease as much as in cardiomegalies with pressure or volume overload.

Acromegaly↗
PubMed1980

[Structural changes of Hancock bioprostheses in children (author's transl)].

Conservative management is the treatment of choice for either congenital or acquired valvular disease in children. However, prosthetic valve replacement may sometimes be required and in this situation the surgeon is faced with the problem of which valvular substitute is the best for this particular patient. The glutaraldehyde-preserved Hancock porcine xenograft has been considered the safest one to use in the pediatric age group since the risks of thromboembolism as well as the mortality and morbidity related to anticoagulant treatment are reduced with this device. However durability of porcine bioprostheses at this time is still unknown, and it remains one of its major concerns. Recent reports have highlighted that porcine heterografts implanted in children undergo early and severe fibrocalcific degeneration. After having reviewed our pathological collection of explanted Hancock valves we have summarized our experience with pathology of porcine bioprostheses in young patients in the present report. Five Hancock heterografts were available for gross and histologic examination. They came from 3 children, 2 females and 1 male, who died or were reoperated upon because of prosthetic dysfunction. Both girls, aged 8 and 10 years, had undergone total correction of complete a-v canal which required mitral valve replacement in the first and mitrotricuspid valve replacement in the second. The first one was reoperated 2.10 years after surgery because of severe prosthetic stenosis and died in the 1st postoperative day of low output syndrome. The second, who developed the signs of mitral stenosis 3.4 years later, was successfully reoperated, but died in severe heart failure 2.9 years following mitral prosthetic re-replacement. The third patient, a 11-year-old boy, underwent mitral valve replacement because of mitral incompetence due to bacterial endocarditis; 5.4 years after surgery he necessitated reoperation because of mitral prosthetic stenosis. He is currently asymptomatic. Pathologic examination of the 5 explants (4 mitral, 1 tricuspid) which had been in place from 34 to 72 months (average 49 mos), showed a severe stenosis with impairment of the effective prosthetic orifice in all. The stenosis was due to coarse calcific deposits of the cusps and commissures and was worsened in 3 cases by fibrous tissue overgrowth on the inflow aspect of the leaflets. In 2 cases an atrial thrombosis was observed, as a consequence of prosthetic stenosis. Histologic examination together with microradiographic investigation showed in all cases the presence of diffuse calcifications of commissures and leaflets. Our pathological experience confirms that the Hancock bioprostheses, when implanted in children, undergoes structural changes early and severe enough so as to discourage their employment in this group of patients.

Bioprosthesis↗
PubMed1980

[The solitary pulmonary nodule. A radiologic and clinical approach (author's transl)].

The cases of pulmonary coin lesions operated at the National Cancer Institute of Milan during the last ten years are presented. Both the disadvantages of early thoracotomy as well as watchful waiting are discussed. Therefore different parameters with the aim to select the patients with the highest probability of cancer are analysed. Finally we tried to identify a diagnostic-therapeutic approach to reduce the complications and risks of thoracotomy in non-oncologic patients.

Adult↗
PubMed1979

X pentasomy: a case and review.

A 49,XXXXX girl is reported. The most typical features of the patient are: severe mental retardation, serious dental anomalies, various anomalies of the bones, and a high rate of gonadotropins. The few similar cases so far described are reviewed to aid in delineation of this rare syndrome. The implications of Lyon's hypothesis on X-aneuploidies are also discussed.

Aneuploidy↗