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Biomedical subjects

M Valente

Publications and source records attributed to M Valente.

At least 181 records · Page 10Linked to original sources
PubMed1988

Lung resection as salvage treatment for metastatic osteosarcoma.

Resection of pulmonary metastases has achieved a central role in the overall management of osteosarcoma, since a number of studies have demonstrated that salvage surgery is able to cure 20 to 40% of all relapsing patients. This paper presents the results of surgical management of 27 consecutive cases of pulmonary metastases from osteosarcoma, who underwent complete resection at the Istituto Nazionale Tumori of Milan between 1975 and 1986. In the present series, overall actuarial survival at 3 years from the first thoracotomy was 47%, with a median survival of 28 months and no operative mortality. Better results were observed in patients with single lesions (68% survival) or when the interval to lung metastases exceeded 12 months (60% survival). These data support the concept of pulmonary metastasectomy as effective salvage therapy for metastatic osteosarcomas whose distant spread is confined in the lungs.

Adult↗
PubMed1988

Modified Schoemacher resection for distal gastric cancer.

Between October 1979 and February 1987, 30 consecutive patients with cancer of the lower stomach underwent B1-Schoemacher resection with a tubular gastric pouch. Operative mortality was 0% and operative morbidity 10% (leak 3%, anastomotic stricture 3% and abscess 3%). After a mean follow-up of 30 months, the expected 5-year survival was 32%. The causes of death were: 7 distant relapses, 2 noncancer diseases and 1 new primary cancer. The overall incidence of postgastrectomy symptoms was 23% for the whole series and 35% for the patients harboring small tumors. Mild dyspepsia occurred in 71%. The declining concept of total gastrectomy as an essential requirement for curative resection and the recent evidence that B2 for gastric lesions is a carcinogenic operation necessitate alternative procedures. The data show that modified Schoemacher resection can be consider a valid challenge to B2.

Aged↗
PubMed1988

Late results after sleeve or wedge lobectomies for non-small-cell lung carcinoma.

From January 1971 to June 1983, 35 lobectomies with bronchoplastic procedures for invasive non-small-cell lung carcinoma were performed. Sleeve lobectomy was carried out in 21 cases, wedge lobectomy in 11, and upper sleeve bilobectomy in 3. There were 23 stage I, 10 stage II, and 2 stage IIIa tumors. Completion pneumonectomy was required in 1 case for anastomotic fistula and in 2 for atelectasis of residual lung. One of these patients died later due to empyema. The 5-year probability of death with recurrence was 31.98%. The 5-year disease-free survival was 58.57%. Metastatic relapse was observed in 8 cases and loco-regional recurrence in 5. A new primary lung tumor occurred in 2 patients.

Aged↗
PubMed1988

Thyroid hormone and the mitochondrial population in the rat heart.

The effects of the thyroid hormone on the number and protein content of mitochondria were investigated in rat heart. The specific mitochondrial population, determined by direct counting, was estimated to be about 3.7 X 10(11) mitochondria per g wet weight in young hypothyroid male rats (T) and about 2.4 X 10(11) (65%) in euthyroid animals, sex- and age-matched. Triiodothyronine (T3) treatment of T animals restored the levels to normal values. The protein content per mitochondrion, on the contrary, was higher in euthyroid animals or hypothyroid animals, following T3 treatment, compared to T. Finally, thyroid hormone enhanced the heart mass and, therefore, the cardiocytal and mitochondrial populations of the whole organ. These results differ from previous data from our laboratory indicating that liver weight is increased by thyroid treatment, albeit at a slower rate, while the number of mitochondria per g tissue increases and the protein content per mitochondrion decreases. In conclusion, the effects of the thyroid hormone on mitochondria are different in the hepatocyte and in the cardiocyte. It appears that the hormone differently modulates the machinery of mitochondrial protein synthesis in the two target cells according to the physiological role of mitochondria in liver and heart cells, i.e. heat production or mechanical energy output, respectively.

Animals↗
PubMed1988

Importance of early recanalization of the occluded coronary artery in acute myocardial infarction for preservation of left ventricular function.

Ninety-two patients with acute myocardial infarction, treated with intracoronary thrombolysis within 3 h from the onset of ischemic symptoms, were studied with coronary arteriography and left ventriculography. These examinations were repeated after 2 to 4 weeks to assess the importance of duration of ischemia on recovery of regional and global left ventricular pump function. Patency was achieved acutely and maintained at control angiography in 73 patients (87%), who were subdivided into three groups according to duration of ischemia before reperfusion: group 1 (29 patients): revascularized within 3 h; group 2 (22 patients): revascularized between 3 and 4 h; group 3 (22 patients): revascularized after 4 h. Patency was acutely achieved, but not maintained at control angiography in 11 patients (group 4), while thrombolysis was unsuccessful in eight patients (group 5). In group 1 there was a significant reduction in the number of hypokinetic segments (P less than 0.001) and a significant increase in mean percentual area change of hypokinetic segments (P less than 0.001) and in global ejection fraction (P less than 0.001). A still significant, but less evident improvement in these parameters was also seen in group 2 (P less than 0.05, P less than 0.01, P less than 0.01 respectively). Insignificant changes, with only occasional improvements were observed on group 3, while a tendency toward deterioration was found in group 4. A clear and significant (P less than 0.001) worsening of local and global ventricular function was detected in group 5. Our results indicate a significant inverse relationship between duration of ischemia and left ventricular functional improvement. Particularly, the first 3 to 4 h after onset of ischemic symptoms are critical for preservation of left ventricular function (group 1 and 2). Reperfusion after 4 h (group 3) is only rarely associated with improvement of ventricular motion. The importance of very early pharmacological thrombolysis and of maintenance of coronary patency is stressed.

Aged↗
PubMed1988

The Hancock pericardial xenograft: incidence of early mechanical failures at a medium-term follow-up.

The Hancock pericardial xenograft has been used in our Institution since August 1981 as an alternative to porcine bioprostheses. Up to July 1984, 97 Hancock pericardial xenografts have been implanted in 84 patients; of 76 operative survivors with a mean age of 55.2 +/- 13 years (range 13-75 years), 50 had undergone aortic valve replacement, 16 mitral valve replacement and 10 mitral-aortic valve replacement. Follow-up ranged from 0.5 to 5.2 years with a cumulative duration of 239 patient/years and is 99% complete. Actuarial survival is 92% +/- 4% for patients with aortic valve replacement and 84% +/- 10% for patients with mitral valve replacement at 5 years, and 77% +/- 14% for those with mitral-aortic valve replacement at 4 years. Thromboembolic episodes occurred in 2 patients (1 after aortic and 1 after mitral valve replacement). The actuarial freedom from emboli is 100% for patients with mitral-aortic valve replacement at 4 years, and 96% +/- 3% for patients with aortic and 93% +/- 6% for patients with mitral valve replacement at 5 years. Reoperation was performed in 13 patients (9 aortic, 2 mitral and 2 mitral-aortic valve replacements), because of endocarditis in 3 (2 aortic and 1 mitral valve replacement), paravalvular leak in 1 (aortic valve replacement), and primary tissue failure in 9 (6 aortic, 1 mitral and 2 mitral-aortic valve replacements). Actuarial freedom from primary tissue failure is 72% +/- 9% for aortic and 83% +/- 8% for mitral Hancock pericardial xenografts at 5 years. Eleven xenografts explanted because of primary tissue failure were studied pathologically.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Lung cancer chemoprevention with retinol palmitate. Preliminary data from a randomized trial on stage Ia non small-cell lung cancer.

On the basis of epidemiologic and experimental evidence of an anticancer activity of vitamin A, a randomized clinical trial was activated in Milan with the aim of evaluating if retinol palmitate administration (per os, 300,000 I.U. daily) after complete resection of stage Ia non small-cell lung cancer could reduce the occurrence of cancer relapses (within 3 years) and/or the occurrence of new primary tumors (beyond 3 years). By September 1987, 181 patients had entered the trial: 87 in the treatment arm and 94 in the control arm. After a median follow-up of 14 months, the interim analysis was focused on the evaluation of toxicity, compliance, and early recurrences. Although the large majority of patients were affected by skin and mucous membrane desquamation and dryness during treatment, these symptoms were generally mild and well tolerated, and never induced the patient to stop the treatment. Other side effects like headache, hair loss, itching, or dyspepsia were detected at a much lower frequency. Only in 3 patients the treatment was interrupted, because of signs or symptoms potentially related to vitamin A administration. At the time of the analysis, a total of 42 (23%) patients had relapsed; 16 (18%) in the treated arm, and 26 (28%) in the control arm. The largest difference between treated patients and controls was observed for bone metastases (2 vs. 7) and brain metastases (3 vs. 6), and for squamous histology (6 vs. 11). Only 2 cases of new primary cancer were detected, both in the control arm. These results are promising both in terms of tolerance and efficacy of treatment, but given the short median follow-up they must be very cautiously interpreted. A longer follow-up is necessary to establish whether a significant proportion of early recurrences could be prevented, or only delayed, by vitamin A administration.

Adolescent↗
PubMed1987

Five-year recurrence probabilities in 330 patients curatively resected for stage Ia bronchogenic carcinoma.

Three hundred and thirty consecutive cases of resected Stage Ia (TNM UICC classification) lung carcinomas were retrospectively reviewed with the aim of evaluating actuarial probabilities of recurrence within the 5th year from operation, according to the extent of resection, the cell type, and the T number. The probabilities of recurrence according to the pattern of failure were also assessed. Five-year overall probability of recurrence was 46.3%. Pneumonectomies showed a lower rate of relapse (37.4%) than lobectomies (49.2%), even though non significant. However, patients submitted to a lobectomy had a higher rate of 5-year survivors. Cell type had no significant impact on the probability of recurrence. 35.5% of patients with T1 carcinomas had evidence of relapse compared with 51.1% of patients with T2 tumors. This datum is explained by the presence in T1 group of a high share of squamous cell cases. Patients with T1 squamous cell carcinomas had, in fact, the best prognosis (26.5% recurred) among the subgroups obtained by stratification of T number and cell type together; loco-regional failure as exclusive modality of relapse had a 5-year rate of 19.7% and metastatic failure of 30.0%. Adenocarcinomas had a significantly higher impact on the occurrence of brain metastases.

Adult↗
PubMed1987

Current results of esophageal cancer surgery. Time trends in operative mortality and long term survival.

This paper represents a historical analysis of the results achieved by esophageal cancer surgery over the last three decades, as they appear in the literature of the years 1954-1985, and in our own experience between 1965 and 1985, with the aim of assessing the evolution of operative mortality and long-term survival. In a review of 4930 resections reported in western literature, mean values of perioperative mortality went down from 30% to 9%, while the five-year survival increased from 8% to 19%. Similar changes were evident in Japanese and Chinese literature where the survival rose from 9% to 23% in unscreened populations and up to 90% in early cancers. In our experience, dividing the series in two decades (1965-74 and 1975-85), the overall perioperative mortality changed from 28% to 13%. The actuarial survival for the two periods was 8% vs 18% at 5 years, with a median survival of 9 and 18 months. A greater difference was evident for N0 patients where the survival rose from 15% to 35% at 5 years, with a median survival of 15 vs 38 months.

China↗
PubMed1987

Pleural mesothelioma of epithelial type and pulmonary adenocarcinoma: an ultrastructural and cytochemical comparison.

Twelve diffuse pleural mesotheliomas of epithelial type have been compared with 20 intrapulmonary adenocarcinomas. All mesotheliomas were negative for epithelial mucin by diastase periodic acid Schiff staining and for carcinoembryonic antigen by immunoperoxidase staining, whereas 17/20 carcinomas stained for epithelial mucin and 15/20 for carcinoembryonic antigen. Hyaluronidase-sensitive alcian blue positive material was present in 6/10 mesotheliomas and 0/20 carcinomas. Previously described electron microscopic differences were validated, including one which has so far received insufficient emphasis: microvilli making direct contact through basement membrane deficiencies with collagen fibres on the abluminal side of tumour cells were identified in 10/12 mesotheliomas and in 0/20 carcinomas.

Adenocarcinoma↗
PubMed1987

Post bending of the polypropylene flexible stent in mitral Hancock bioprostheses.

The occurrence of stent post deformity was investigated in 38 consecutive, polypropylene flexible-stented Hancock porcine bioprostheses (PB) recovered from the mitral position because of early postoperative death or late tissue failure. The degree of deformity was assessed for each explant by calculating the triangular area obtained by projecting the apex of the stent posts on a plane and comparing it with the same area calculated for unimplanted PBs of comparable size. A significant stent deformity (reduction of the triangular area greater than 40%) was observed only in 6 PBs explanted because of tissue failure after a mean function time of 69.6 +/- 28 months. In these PBs, scanning electron microscopy of the bare surface of the stent at the point of maximal flexion showed cracks 0.7-1 microns large, which represent the morphological substrate of the so-called "creep" of polypropylene. Inward stent post bending may occur after implantation in mitral PBs and when severe, it corresponds to a definite ultrastructural plastic deformity of polypropylene.

Animals↗
PubMed1987

Familial histiocytic dermatoarthritis. Histologic and ultrastructural findings in two cases.

We report the clinical, histological, and ultrastructural study of two patients, mother and daughter, 32 and six years old, respectively, who presented with dermatitis and arthritis. From the clinical point of view, they appeared to be affected by Familial Histiocytic Dermatoarthritis (FHD), a diagnosis supported by the early age of onset, familial occurrence, and a typical ocular lesion in the mother (glaucoma, uveitis, and cataracts). However, histology revealed the presence of multinucleated giant cells that are usually associated with Multicentric Reticulohistiocytosis (MR). Unlike MR, in the cases here reported the PAS positive, intracytoplasmic material appeared to be glycogen. Electron microscopy disclosed pleomorphic bodies, which have also been described in MR. Thus, we conclude that FHD and MR probably do not represent separate entities, and that a spectrum of disorders exists between these two conditions.

Adult↗
PubMed1987

Prevention of lipid peroxidation by NAD(P)H in rat liver submitochondrial particles.

In rat liver submitochondrial particles both NADH and NADPH inhibit lipid peroxidation induced by cumene hydroperoxide. Concomitantly with the inhibition of lipid peroxidation, NADH and NADPH strongly stimulate the peroxidase activity of rat liver submitochondrial particles. Rotenone slightly prevents both the protective effect on malondialdehyde formation and peroxidase activity. The peroxidase activity of rat liver submitochondrial particles was attributed to the NAD(P)H-mediated reduction of mitochondrial cytochrome P-450 which can act upon hydroperoxides, by decomposing them to alcohols.

Alcohols↗
PubMed1987

Early mechanical failures of the Hancock pericardial xenograft.

From August 1981 to July 1984, a total of 97 Hancock pericardial xenografts were implanted in 84 patients, whose ages ranged from 13 to 75 years (mean 55.7 +/- 13). Mitral value replacement was performed in 17, aortic valve replacement in 54, and mitral-aortic valve replacement in 13. Operative survivors were reevaluated from July to September 1985. Cumulative duration of follow-up is 167 patient-years (range 0.5 to 4.1 years), and follow-up is 99% complete. The overall late mortality (at 4 years) is 3.6% +/- 1.4% per patient year, and the actuarial survival rate is 95.4% +/- 3% for aortic valve replacement, 74.7% +/- 16.5% for mitral valve replacement, and 67.1% +/- 20.7% for mitral-aortic valve replacement. One patient sustained a thromboembolic event after mitral valve replacement, but no such complications occurred after aortic or mitral-aortic valve replacement. Actuarial freedom from embolism at 4 years is 100% for aortic and mitral-aortic valve replacement and 93.3% +/- 6.4% for mitral valve replacement. Reoperation for Hancock pericardial xenograft dysfunction was performed in seven patients (five aortic and two mitral-aortic). In the aortic valve replacement group the causes were endocarditis in one, paravalvular leak in one, and primary tissue failure in three; all survived reoperation. The two patients with mitral-aortic valve replacement required reoperation because of primary tissue failure of both Hancock pericardial xenografts, and one died. All values explanted because of primary tissue failure showed commissural tears causing severe prosthetic regurgitation. Calcium deposits were severe in one and mild but unrelated to the cusp rupture in another. Collagen disarray was seen only at the site of the tears, whereas the collagen structure was well preserved in the intact parts of the cusps. Four patients with aortic valve replacement and one with mitral valve replacement show evidence of Hancock pericardial xenograft failure and are awaiting reoperation. The actuarial freedom from primary tissue failure at 4 years is 74.3% +/- 9.8% for aortic and 78.9% +/- 13.2% for mitral Hancock pericardial xenografts. At medium-term follow-up, the Hancock pericardial xenograft has shown poor durability and an extremely high rate of early mechanical failure, especially in the aortic position. These observations suggest the need for a close follow-up of Hancock pericardial xenograft recipients and possibly elective reoperation in asymptomatic patients with clinical evidence of prosthetic failure. These results have led us to discontinue the clinical use of this pericardial xenograft.

Adolescent↗
PubMed1987

Dissecting cuspal hematomas. A rare form of porcine bioprosthetic valve dysfunction.

Large dissecting cuspal hematomas (DCHs) were present in six (3%) of 193 porcine bioprostheses (PBs) explanted at reoperation. In four mitral PBs, the DCHs contributed to valve dysfunction; in one aortic PB, DCH was the only determinant of failure, causing stenosis by cusp thickening and rigidity. In another mitral PB, DCHs were occasionally found in the setting of valve incompetence due to commissural tears. While confirming that DCHs are a potential but infrequent cause of PB failure, these observations demonstrate that they may involve PBs implanted both in mitral and aortic position and might be a complication of anticoagulation.

Adult↗