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Biomedical subjects

M Valente

Publications and source records attributed to M Valente.

At least 145 records · Page 8Linked to original sources
PubMed1991

Laboratory evaluation during high-dose vitamin A administration: a randomized study on lung cancer patients after surgical resection.

The laboratory findings in patients receiving high-dose vitamin A as adjuvant treatment for stage I lung cancer are here reported. A group of 283 patients were randomized to either treatment with retinyl palmitate (300,000 IU daily for 12 months) or standard follow-up, and are now evaluable after a median observation period of 28 months. At regular intervals, all the patients underwent a physical examination, chest roentgenogram, blood chemistries, haematological assays, hepatic and renal function tests and determinations of serum triglycerides and cholesterol. Serum transaminase abnormalities were of similar magnitude in cases and controls, while gamma-glutamyltransferase levels were abnormally elevated in 69% of the treated patients compared to 39% of controls (mean values 149 vs 57 IU/l at 24 months, P less than 0.05). Serum triglyceride concentrations over 150 mg/dl were seen in 74% of treated patients compared to 43% of controls at 12 months, the average concentration was 283 mg/dl compared to 179 mg/dl (P less than 0.05). Cholesterol levels showed a modest, non-significant rise with time in both groups, and there was no other laboratory evidence of toxicity attributable to vitamin A. Serum retinol and retinol-binding protein, assessed on a limited sample of patients, were higher in the treatment arm (P less than 0.05) at 12 months. In our experience 300,000 IU/day of retinyl palmitate can be administered as a possible chemopreventive agent with reasonable safety for up to 2 years.

Aspartate Aminotransferases↗
PubMed1991

Reliability and intersubject variability of the real ear unaided response.

Intratester test-retest reliability of the real ear unaided response (REUR) was determined on 49 ears using the Frye 6500 real ear analyzer. Results revealed mean differences of less than 1 dB for repeat measurements at seven test frequencies between 250 and 4000 Hz. The average peak resonant frequency of the repeated measure was within 16 Hz of the initial measure. In addition, the intersubject variability of the amplitude of REUR was quite large. A range of 7 dB was found at 250 to 500 Hz with the range expanding to 15 to 20 dB at 2000 to 4000 Hz. Also, the peak resonant frequency varied between 2100-4800 Hz. These results are discussed in terms of those dispensers who use the REUR to "custom" order hearing aids.

Acoustics↗
PubMed1991

Safety of high-dose vitamin A. Randomized trial on lung cancer chemoprevention.

The paper reports on the efficacy and side effects of high-dose vitamin A, administered as adjuvant treatment for resected stage I lung cancer in a randomized clinical trial. After a median follow-up of 28 months, 283 patients were evaluable: 138 allocated to treatment with retinol palmitate (300,000 IU daily for at least 12 months) and 145 to standard observation. The clinical results available to date do well justify a continuation of the study. Skin dryness and desquamation were the most frequent symptoms, affecting 60% of all treated patients. Other symptoms such as dyspepsia, headache, nosebleeds and mild hair loss occurred in less than 10% of patients, and were self-terminating. Only in 4 patients (3%) was the treatment interrupted because of symptoms potentially related to vitamin A administration. As for laboratory tests, gamma-GT levels were abnormally elevated in 69% of treated patients vs. 39% of controls at 24 months (mean 149 vs. 58 IU/l; p less than 0.05). Serum triglyceride concentrations over 150 mg/dl were seen in 74% of treated patients vs. 43% of controls at 12 months (mean 283 vs. 179 mg/dl; p less than 0.05). There were no other laboratory signs of toxicity attributable to vitamin A. In our experience, high-dose retinoyl palmitate administration was a well-tolerated and safe treatment. The long-term impact on lipid metabolism still remains to be determined.

Alkaline Phosphatase↗
PubMed1991

The contribution of salvage surgery to the management of childhood osteosarcoma.

Between January 1970 and December 1988, 174 consecutive patients under the age of 20 years with curatively resected primary osteosarcoma were treated at our institute; 72 in the years of 1970 to 1981 and 102 in the years 1982 to 1988. In the latter period, adjuvant chemotherapy was replaced by neoadjuvant programs, and new criteria were adopted for the management of lung metastases, consisting in early bilateral surgical staging and lung resection through median sternotomy for all patients with purely intrathoracic relapse. Follow-up was updated in December 1989. During the last period, the overall 5-year survival improved significantly from 35% to 58% (P less than .001). The disease-free survival rose from 38% to 45% at 5 years, with median values of 15 months versus 33 months, while the frequency of isolated lung metastases dropped from 58% to the actuarial 48%. The proportion of patients who underwent complete resections of their pulmonary metastases rose from 17% (seven of 42) to 55% (27 of 49), without operative mortality. Due to such a high proportion of patients eligible for salvage surgery, the overall survival from detection of lung metastases improved from 0% to 28% at 5 years (P less than .001). Contralateral occult metastases were resected in three of 15 subjects with monolateral clinical lesions, and five patients underwent subsequent lung resections. These data indicate that systematic bilateral pulmonary resection plays an important role in improving the final cure rate of childhood osteosarcoma, beyond the benefit resulting from neoadjuvant chemotherapy.

Adolescent↗
PubMed1991

Stroke-cirrhosis relationship: an autopsy study in a heavy drinking population.

A positive association between alcohol consumption and stroke incidence has been clearly established. The present study evaluated the frequency of stroke in a sample of 500 autopsied patients affected by liver cirrhosis mainly due to chronic alcohol abuse as confirmed by the histologic pattern mostly of mixed and micronodular types. Frequency of stroke was compared to that of 4,741 non-cirrhotic patients autopsied in the same period. Our findings demonstrate that stroke frequency, especially when due to thromboembolism, decreased significantly in cirrhotics. Therefore, hepatopathy is a crucial event in alcoholic patients. Nevertheless the concomitant presence of liver cirrhosis, in studies dealing with this subject, is not being currently evaluated.

Age Factors↗
PubMed1991

Limited resection for Stage I lung cancer.

We have reviewed our experience of limited resections for Stage I lung cancer for the years 1971-88. Sixty-one cases of sublobar resection (wedge or segmental) were compared with 411 lobar resections (lobectomies or bilobectomies), performed over the same period. Operative mortality was 0% in the limited resection group and 3% (12/411) in the control group. Cancer recurrence was detected respectively in 36% and 38% of patients, and actuarial survival at 5 years was 55% versus 49% overall. Sublobar resection had a slightly better outcome than lobar resection in pathological T1 (5-year survival of 73% vs 55%) but a worse outcome in pT2 (35% vs 46%); however, none of the differences was statistically significant. In 28 patients with pre-existing cardiac or pulmonary co-morbidity, limited resection yielded the same 5-year survival as lobectomy (53% vs 51%) with no peri-operative deaths (0 vs 5%). Although derived from a retrospective analysis, these data offer a further confirmation that limited resection combined with adequate nodal staging is a reliable and effective technique for early stage lung cancer management.

Aged↗
PubMed1990

Incident lung cancer survival. Long-term follow-up of a population-based study in Italy.

The long-term survival of an incident lung cancer population was evaluated in relation to clinical stage, treatment modalities and other prognostic factors. The survey was carried out among the residents in the Local Sanitary Unit of Saronno, a highly industrialized area of northern Italy, where all the lung cancer cases diagnosed during the years 1976-79 had been identified and clinically studied. The overall survival of the 222 cases included in the analysis was 32% at 1 year, 10% at 3 years and 5% at 5 years; median survival was 7 months. A significantly better prognosis was associated with surgical resection (32% at 5 years; median, 42 mo), clinical stage I (16% at 5 years; median, 15 mo), and squamous cell carcinoma (13% at 5 years; median, 11 mo). Other factors such as age, sex, social class or cancer symptoms did not affect survival when treatment was taken into account. Our data show that surgical resection is the major determinant of survival, and suggest that sub-optimal access to curative treatment, particularly in patients aged 60 to 75 with limited disease, might have compromised the overall survival.

Adenocarcinoma↗
PubMed1990

Results of conservative surgery for stage I lung cancer.

This paper reports our results with sublobar resections for stage I non small cell lung cancer. Sixty-one cases of wedge or segmental resection were compared with 517 standard resections (411 lobectomies and 106 pneumonectomies), performed during the years 1971-88. Operative mortality was 0% in the limited resection group and 4% (19/517) in the standard resection group; cancer recurrence was detected in 36% of both groups; actuarial survival at 5 years was 55% versus 48% overall. In 28 patients with pre-existing cardiac or pulmonary co-morbidity, limited resection yielded a similar 5-year survival than standard resection (53% vs 49%) with no perioperative deaths (0 vs 6%). Our data support the experience of other authors on conservative management of stage I lung cancer. Particularly in patients with concomitant cardio-pulmonary disease, previous cancer or small peripheral tumors, limited resection combined with adequate nodal staging may be as effective as standard lobar resection with respect to long term survival.

Adult↗
PubMed1990

Ketanserin and captopril interaction in the treatment of essential hypertensives.

The aim of the study was to evaluate whether the combination of ketanserin with captopril exerts an additive antihypertensive effect, as compared with single drug treatment. Twelve patients with uncomplicated moderate essential hypertension received, according to a randomized, double-blind, crossover design, ketanserin (40 mg twice daily), captopril (50 mg twice daily), the combination of the two drugs at these dosages, and the corresponding placebo, each treatment being given for 1 month. Both ketanserin and captopril as monotherapy similarly and significantly reduced blood pressure as compared with placebo (p less than 0.001). The combination treatment of ketanserin plus captopril further and significantly reduced blood pressure when compared with single drug treatment (p less than 0.001). Moreover, the percentage of responders and patients whose blood pressure was normalized were significantly greater under the combined treatment than under ketanserin or captopril monotherapy (p less than 0.001). These data indicate that the combination of ketanserin plus captopril exerts a clear additive antihypertensive effect when compared with each treatment as monotherapy, a finding that suggests this combination can be usefully employed in the treatment of hypertensive patients.

Adult↗
PubMed1990

Degenerative, non-atherosclerotic cardiovascular disease in the elderly: a clinico-pathological survey.

Cardiovascular disease, the major cause of death in the elderly, is mostly ascribable to complications of coronary atherosclerosis: angina pectoris, myocardial infarction, and sudden death. However, other degenerative diseases involving several cardiac structures exist, and should be distinguished from age-related cardiac changes. Extensive dystrophic calcification determines aortic stenosis, and may affect either a normally tricuspid or a congenitally bicuspid valve. Surgical valve replacement is now a low risk option, even in elderly persons, whereas the efficacy of balloon valvuloplasty is questionable. Aortic incompetence in adults and aged persons is mostly the consequence of aortic tunica media atrophy with anular ectasia, in the setting of nearly normal aortic leaflets. Mitral valve prolapse is the main cause of mitral incompetence; spontaneous cordal rupture is a late complication in the natural history of this disease, thus warranting prompt surgical valve repair or replacement. The entire spectrum of cardiomyopathies is observed in the elderly: dilated, hypertrophic, restrictive, arrhythmogenic. Cardiac amyloidosis is by far the most frequent secondary form and leads to congestive heart failure by impairing ventricular compliance. Idiopathic fibrosis of the specialized AV junction or dystrophic calcification of central fibrous body are the usual substrates of AV block, which requires pace-maker implantation. Nonrheumatic atrial fibrillation, due to fibro-fatty degeneration of the atrial musculature or dilated left atrium, carries a high risk of thromboembolic complications and cerebral accidents; oral anticoagulants have proven to be effective in preventing stroke. Aortic dissecting aneurysm is a spontaneous laceration, and usually a complication of longstanding systemic hypertension; exceptionally, spontaneous dissection may primarily occur in the coronary arteries. In conclusion, longevity at present is mostly threatened by cardiovascular disease, among which the role of degenerative, non-atherosclerotic disorders may be greater than thought.

Aged↗
PubMed1990

The protective action of pyruvate on recovery of ischemic rat heart: comparison with other oxidizable substrates.

The recovery of both contractile performance and metabolic response of rat heart following 1 h of ischemia after equilibration with glucose + insulin (glucose-ischemia) or with pyruvate (pyruvate-ischemia), was tested in normoxic reperfusion in the presence of glucose + insulin, pyruvate, lactate or acetate. In glucose-ischemia only the reperfusion with pyruvate results in a complete recovery of the contractile force (left ventricular pressure, LVP) (170%) and good recovery of high energy phosphate compounds. Lower LVP and tissue energy charge were found in glucose reperfusion and even less in lactate and acetate reperfusion. Disappearance of the IMP accumulated during ischemia is evident only in the pyruvate reperfusion indicating a higher metabolic recovery. On the contrary in pyruvate-ischemia all types of reperfusion tested were effective in reactivating the contractile force (although acetate to a lesser extent); the contractile activity was accompanied by a good recovery of phosphocreatine, ATP, energy charge and by the decrease of IMP. Large decreases of adenine nucleotides and NADP and lower decreases of NAD are observed during ischemia/reperfusion in both systems. Pyruvate-ischemia is quite similar to, if not worse than glucose-ischemia, for all the metabolic parameters considered, but not worse for the possibility of recovery. Some specific effect of pyruvate should be exerted during the ischemic phase. The mechanism of pyruvate protection is discussed in relationship to: (i) the possible activation of pyruvate dehydrogenase, (ii) the activation of NADPH-dependent peroxide scavenging systems, (iii) the direct scavenging action of pyruvate on H2O2.

Acetates↗
PubMed1990

Median sternotomy and multiple lung resections for metastatic sarcomas.

In the attempt to apply salvage surgery to the majority of patients with pulmonary tumour relapse, we have adopted a new treatment plan consisting of early bilateral lung exploration and resection through median sternotomy in all cases of sarcoma with resectable lung metastases, including synchronous or previously resected ones. The present paper summarizes the early results achieved with this technique in 56 consecutive patients treated between 1985 and 1988. Perioperative mortality was zero, and morbidity negligible. Occult contralateral metastases were resected in about one third of subjects with monolateral clinical lesions. Overall actuarial survival from first pulmonary resection is 51% at 2 years and 35% at 3 years. A slightly more favourable trend is evident for solitary lesions but the difference is not statistically significant. No difference in survival is observed in relation to the initial disease-free interval or to the histological type. The majority of relapses occurred within 6 months of sternotomy (23/35) and were confined to the lungs (21/35). Ten of these 21 patients with pulmonary relapse have undergone further resection and 5 of them are alive, with a median survival of 28 months. Present results are encouraging as far as resectability and early recurrence rate are concerned. Median sternotomy appears a most valuable therapeutic approach to pulmonary metastases from sarcomas, being safe and effective in local control of disease, and compatible with further surgical management of pulmonary recurrences.

Adolescent↗
PubMed1990

Results of salvage surgery for metastatic sarcomas.

Between January 1970 and December 1988, 105 consecutive patients underwent complete resection for lung metastases from sarcoma, 33 of them in the years from 1970 to 1983 and 72 between 1984 and 1988. In the latter period, new criteria consisting of early bilateral surgical staging and lung resection through median sternotomy were adopted for the management of lung metastases, in all patients with purely intrathoracic relapse. There was no operative mortality, follow-up was updated in August 1989, and actuarial survivals were calculated by the logrank method at 36 months from the time of first lung resection. During the second period, the overall actuarial survival at three years improved significantly (24% vs. 50%, P less than 0.02), notwithstanding the higher incidence of patients with unfavourable prognostic factors. The three-year survival was also significantly better in the subset of patients with a disease-free interval less than or equal to 12 mos. and/or multiple pathological lesions (9% vs. 45%, P less than 0.05). Contralateral occult metastases were resected in 10 of 29 subjects who underwent sternotomy for monolateral clinical lesions. Of 26 patients with further intrapulmonary recurrence, 16 (62%) were amenable to re-operation and eventual surgical rescue. These data suggest that median sternotomy and early management of occult contralateral disease may contribute to an improvement in the long-term survival of patients with metastatic sarcomas. On the other hand, it is possible that the effectiveness of salvage surgery is related to the higher activity and wider application of adjuvant and salvage chemotherapy.

Adolescent↗
PubMed1990

Intratester test-retest reliability of insertion gain measures.

Intratester test-retest reliability of insertion gain was determined on 28 subjects using the Frye 6500 real-ear analyzer. Results revealed mean differences of less than 1 dB for repeat measurements at six test frequencies between 250 and 4000 Hz. Also, over 80% of the repeat measures were within +/- 3 dB of the first measure. The results of this study are compared with previous studies of intratester reliability of insertion gain measures.

Aged↗
PubMed1990

The pathology of Hancock standard porcine valve prosthesis: a 20-year span of experience.

A spectrum of events leading to tissue failure is responsible for late dysfunction of Hancock porcine valve xenografts: (a) Primary failure: dystrophic calcification, thrombosis, fibrous tissue overgrowth, primary tears, cuspal hematomas, and stent postbending. (b) Secondary failure: endocarditis and paravalvular leak. Dystrophic calcification is the main factor influencing long-term durability and accounts in our experience for 88% of primary failure, through different clinical presentations; particularly, incompetence by cusp tearing and egg-shell fragmentation is by far the most frequent mode of failure. Cusp degeneration by primary tears (in the absence of dystrophic calcification) is an uncommon event, due to lipid infiltration or to right coronary muscle shelf spontaneous or immuno-related disruption.

Bioprosthesis↗