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Biomedical subjects

M Valente

Publications and source records attributed to M Valente.

At least 73 records · Page 4Linked to original sources
PubMed1998

HIV infection in the first heart transplantation in Italy: fatal outcome. Case report.

A 46-year-old man with alcoholic dilated cardiomyopathy underwent heart transplantation on November 14, 1985. It was the first cardiac transplant in Italy and at that time no HIV antibody screening test was available in this country. The patient remained in good health for 6 years postoperatively, with only one episode of rejection (type 3A). In June 1992 he died of fulminant complications of AIDS and severe chronic rejection. Neither the patient nor the organ donor belonged to any of the known risk groups for HIV infection; a retrospective analysis revealed that perioperative blood transfusions had been the vectors of transmission.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Glutaric aciduria type 1: phenotypic variability. Report of 6 patients].

We report six patients with glutaric aciduria type 1 in four families. The patients had marked clinical variability, even within families. Three of the patients studied were normal until the onset of neurologic abnormalities, that presented as an encephalitis-like illness in the first year of age. One patient had an early and important developmental delay, but never suffered an encephalopathic crisis. Two patients have intellectual preservation; one of them has a mild tremor and choreoathetosis since the first year of age, and the other had only two afebrile seizures in infancy and no other neurologic signs. Three patients are severely handicapped, with a severe dystonic-dyskinetic disorder and unable to even sit. All the six patients have macrocephaly and in all the computed tomography showed enlarged CSF spaces and sulcal separation over the frontal and temporal lobes. Urine organic acids study of all patients showed large quantities of glutaric acid.

Adult↗
PubMed1998

[Goiter prevalence and urinary excretion of iodine in a sample of school age children in the city of Rome].

The aim of the study was the assessment of the urinary iodine excretion and the evaluation of thyroid volume compared with clinical examination in 1040 schoolchildren (6-14 years old), living in Rome. Mean urinary iodine excretion was 98.52 +/- 49.81 micrograms/l (median 92 micrograms/l). Thyroid enlargement, as assessed by palpation, was found to be grade 1A in 35.4% of the children, grade 1B in 9.6% and grade 2 in 0.2%. Thyroid volume, determined by ultrasound, increased with age, was significantly correlated with body surface area and was significantly higher in females, as compared to males, in the 11 and 12 years old group. Eleven children (1.9%) were negative at palpation (grade 0) but showed thyroid enlargement by ultrasound. The prevalence of goiter determined by ultrasound resulted to be 4.7%.

Adolescent↗
PubMed1998

Novel heart diseases requiring transplantation.

Cardiac transplantation represents an extraordinary opportunity to study in vivo the pathology of native disease in the terminal phase. The experience cumulated at the University of Padua in 418 orthotopic cardiac transplant procedures allowed to come across previously unrecognized disease: idiopathic left ventricular aneurysm, non-compacted (spongy) myocardium, restrictive cardiomyopathy. A discrepancy between pre- and post-transplant diagnosis was found in 8% of cases. Endomyocardial biopsy and coronary arteriography should be carried out in each patient with apparently dilated cardiomyopathy before proceeding to heart removal, since alternative therapeutic procedures may be available.

Journal Article↗
PubMed1998

In vivo evidence of apoptosis in arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary heart muscle disease characterized by progressive atrophy of the right ventricular myocardium with fibro-fatty replacement and the risk of electrical instability and sudden death. The disease is often familial and the aetiopathogenesis is still unknown. Recently apoptosis (genetically determined cell death) was postulated to account for progressive loss of myocardium. To establish whether apoptosis is present in ARVC, right ventricular endomyocardial biopsies from 20 patients with clinical and histological diagnosis of ARVC were examined by electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling method (TUNEL). Apoptotic index was calculated as the percentage of positive nuclei in sections stained by TUNEL. Cell proliferation activity was also assessed by argyrophilic staining of the nucleolar organizer region (AgNOR) and MIB-1 antibody analysis. Twenty biopsies taken from patients during monitoring of cardiac transplantation (grade 0 rejection) served as control. Occurrence of apoptosis was correlated with clinical history duration and the presence of acute symptoms and signs like angina, pyrexia, erythrocyte sedimentation rate and creatine phosphokinase elevation, as well as ST segment elevation on basal electrocardiogram. Electron microscopy and TUNEL revealed presence of apoptotic myocytes in seven cases (35%) with a mean apoptotic index of 24.4+/-9.8. The remaining 13 patients and all of the 20 controls were negative both at the electron microscopy and TUNEL. Presence of apoptosis appeared to be significantly related to clinical history duration of less than 6 months (P < 0.001) and presence of acute symptoms and signs (P = 0.007). AgNOR staining and MIB-1 antibody analysis ruled out cell proliferation activity. In conclusion, apoptosis is present in endomyocardial biopsies of patients with ARVC, especially in the early symptomatic phase of disease. Myocardial destruction with replacement by fat may be episodic rather than gradual and continuous.

Adult↗
PubMed1998

Pathology of the Pericarbon bovine pericardial xenograft implanted in humans.

BACKGROUND AND AIMS OF THE STUDY: Pericarbon is a new-generation bovine pericardial bioprosthesis designed to withstand mechanical wear. Following optimal in vitro testing and animal experiments, clinical trials were initiated in many European centers and explants sent to our department for pathological evaluation. This included gross, radiographic, histologic and ultrastructural investigations. METHODS: Between 1986 and 1996, 24 bioprostheses (eight aortic, 11 mitral, two mitro-aortic, one tricuspid) were collected from 22 patients (10 males and 12 females; mean age 57.0 +/- 18.9 years) either at autopsy (nine) or reoperation (15). RESULTS: Ten bioprostheses explanted < 2 months after surgery were either normal or failed because of surgical problems or non-structural causes. Among the other 14 bioprostheses (mean placement 41.9 +/- 23.6 months; range: 7 to 90 months), structural deterioration occurred in seven and was due to dystrophic calcification with stenosis in five (three aortic, two mitral), mixed lesion in one (mitral), and incompetence in one by calcium-related commissural tear (mitral). At the ultrastructural level, calcification was detected either on cell debris or upon collagen fibers. No bioprosthesis failed because of fibrous tissue overgrowth. Of the remaining seven bioprostheses, vegetative endocarditis occurred in two, thrombosis in one, and aseptic paravalvular leak in one; whereas three showed no signs of dysfunction. CONCLUSIONS: This pathologic experience with the Pericarbon valve showed calcification to be the main cause of late structural failure, causing mainly cusp stiffness and bioprosthesis stenosis. Tissue rupture or abrupt dysfunction never occurred. Thus, prevention of mineralization remains the main challenge.

Adult↗
PubMed1998

Detoxified glutaraldehyde cross-linked pericardium: tissue preservation and mineralization mitigation in a subcutaneous rat model.

BACKGROUND AND AIM OF THE STUDY: Glutaraldehyde is considered a promoter of calcification by the action of toxic aldehyde group residuals from cross-linking. Post-fixation treatment with homocysteic acid (HA), besides bonding aldehyde groups and neutralizing toxicity, should enhance biocompatibility due to the strongly electronegative sulfonic group. The aim of this investigation was to evaluate HA efficacy on tissue preservation and dystrophic calcification mitigation in glutaraldehyde cross-linked bovine pericardium (BP) using a subcutaneous rat model. METHODS: Four samples of BP, two with glutaraldehyde-HA and two with glutaraldehyde treatment, were implanted in each of 24 male Sprague-Dawley rats. Three rats were killed at 14 days, eight at 28 days, eight at 56 days and five at 84 days. Unimplanted glutaraldehyde-HA- and glutaraldehyde-treated samples served as controls. All samples were studied by gross examination, mammography, light transmission and scanning electron microscopy, and atomic absorption spectroscopy. The nature of mineralization was investigated by coupling techniques of scanning electron microscopy, electron microprobe analysis and X-ray powder diffraction. RESULTS: No histological and ultrastructural differences were found between glutaraldehyde-HA- and glutaraldehyde-treated BP, whether implanted or unimplanted. In both groups, calcification progressed with time, but significantly less after glutaraldehyde-HA treatment than after glutaraldehyde alone and at all time intervals (14.63 +/- 21.34 versus 43.17 +/- 15.99 at 28 days, p = 0.003; 56.42 +/- 40.20 versus 90.59 +/- 32.90 at 56 days, p = 0.008; 91.68 +/- 67.68 versus 156.23 +/- 17.85 at 84 days, p = 0.01). Differences were evident by mammography and histology (von Kossa stain). Electron microprobe analysis in both groups showed the composition of calcified nuclei to be calcium phosphate, stoichiometrically close to apatite (Ca5(PO4)3(OH)). The occurrence of crystallized apatite was supported by X-ray powder diffraction findings, the amount of crystallized apatite being higher in glutaraldehyde-treated samples. CONCLUSIONS: Post-fixation treatment with HA preserves BP structural properties and significantly mitigates mineralization of long-term subcutaneous implants.

Animals↗
PubMed1998

[Mathematical model for the predictive value of a test in critically ill patients studies according to APACHE II score and pathology at admission].

OBJECTIVE: To find a predictive model for mortality at four different days from the admission for critically ill patients. DESIGN: Retrospective study on two consecutive series of critically ill patients admitted in ICU. SUBJECTS: 1254 critically ill patients, subdivided into two series of 813 (561 survivors and 252 non survivors) and 441 patients (291 survivors and 150 non survivors), respectively. INTERVENTIONS: None. MEASUREMENTS: All patients had APACHE II calculated within the first 24 hours from the admission in ICU and, if the patient was still in ICU, also at the 5th, 10th and 15th day from the admission. Casistics was subdivided into two unequal series, ratio 2:1, with a random selection made on each of the 6 considered years. On the 1st series, in 1st, 5th, 10th and 15th day, for mathematical predictive models were made, using stepwise logistic regression (BMDP, Los Angeles). In the 1st day the following independent variables were utilized: APACHE II score, the specific diagnosis at admission, fitted following Knaus' diagnostic criteria, united in 6 principal categories, while for the other 3 days the variation % of APACE II score as regards the previous day. RESULTS: For each of the considered day four mathematical models have been made. These models have been validated in both series in calibration from the Hosmer-Lemeshow Goodness-of-fit test and in discrimination from the ROC curves. For each day Y (Prob.% to die) = eLogit/1 + eLogit, where Logit = beta 0 (constant) + beta 1*APACHE II + beta 2*Variat.%APACE II (difference between actual APACHE II - APACHE II of the previous day/actual APACHE II) + beta k, (coefficient pertinent to pathology). CONCLUSIONS: The mathematical model, as other models do, stratifies enough the casistics according to the risk of death. Waiting for further studies to make more precise prognostic mathematical models, this one and others can help the clinical assessment in single patient evaluation.

APACHE↗
PubMed1998

Comparing the performance of the Widex SENSO digital hearing aid with analog hearing aids.

Differences in performance were evaluated between the Widex SENSO and several analog hearing aids currently worn by 50 hearing-impaired subjects. Subjects were initially fit with the SENSO using the manufacturer's recommended procedure. After wearing the hearing aids for 1 week, the adjustable parameters were fine-tuned based on subjective comments. Differences in performance between the SENSO and the subjects' current hearing aids were assessed using the Speech Perception in Noise administered at overall levels of 50, 65, and 80 dB SPL; the Hearing in Noise Test in which the background noise was presented at 50, 65, and 80 dBA; the Abbreviated Profile of Hearing Aid Benefit; and two questionnaires relating to overall preference between the SENSO and the subjects' current hearing aids.

Adult↗
PubMed1997

Cardiac lithomyxoma.

Among 102 consecutive cardiac myxomas, 10 (10%) showed heavy calcification both on gross inspection and on x-ray examination. Mineralization was partial in 6 patients (mean age 56.8 years) and massive stone-like in 4 (mean age 70 years); relevant histologic findings in patients with partial calcification were Gamma-Gandy bodies in 5, cartilaginous and bone metaplasia in 2, and aspecific calcium deposits in 1. All were incidental findings either at autopsy or during clinical investigation.

Calcinosis↗
PubMed1997

Morphologic spectrum of primary restrictive cardiomyopathy.

A restrictive hemodynamic profile with left ventricular (LV) end-diastolic volume < 100 ml/m2 and LV end-diastolic pressure > 18 mm Hg, in the absence of endomyocardial, pericardial, and specific cardiomyopathy, is a peculiar feature of primary restrictive cardiomyopathy. From 1985 to 1994, 7 hearts of patients who met the above hemodynamic criteria and underwent endomyocardial biopsy because of heart failure, were studied through gross (5 cardiectomies and 2 autopsies), histologic, and electron microscopic investigations. Ages ranged from 9 to 48 years (mean age 29 +/- 13). Four patients (57%) had a positive family history: 2 for hypertrophic and 2 for restrictive cardiomyopathy. Three patterns were identified in the 7 hearts: (1) pure restrictive form in 4 cases with mass/volume ratio 1.2 +/- 0.5 g/ml, ejection fraction 58 +/- 5%, LV end-diastolic volume 67.5 +/- 12.6 ml/m2, LV end-diastolic pressure 26.7 +/- 3.5 mm Hg; (2) hypertrophic-restrictive form in 2 cases with mass/volume ratio 1.5 +/- 0.07 g/ml, ejection fraction 62 +/- 1%, LV end-diastolic volume 69 +/- 10 ml/m2, LV end-diastolic pressure 30 +/- 7 mm Hg; and (3) mildly dilated restrictive form in 1 case with mass/volume ratio 0.9 g/ml, ejection fraction 25%, LV end-diastolic volume 98 ml/m2, LV end-diastolic pressure 40 mm Hg. Histology and electron microscopy disclosed myocardial and myofibrillar disarray and endoperimysial interstitial fibrosis in each pattern. The familial forms suggest the presence of a genetic abnormality. Primary restrictive cardiomyopathy may present with or without hypertrophy and shares similar microscopic pictures with hypertrophic cardiomyopathy. The 2 entities may represent a different phenotypic expression of the same genetic disease.

Adolescent↗
PubMed1997

The protective effects of L-arginine after liver ischaemia/reperfusion injury in a pig model.

Hepatic ischaemia/reperfusion is characterized by circulatory and metabolic derangement, liver dysfunction, and tissue damage. To evaluate the role of L-arginine, a substrate of nitric oxide, in ischaemia/reperfusion injury, total liver ischaemia was induced for 120 min in 22 Landrace x Large White female pigs, which were randomly assigned to a treatment group (10 animals) or a control group (12 animals). An L-arginine bolus (540 mg/kg i.v.) was administered to the treatment group 1 h before clamping the hepatic hilum, at clamping, at reperfusion, and at 1 and 2 h after reperfusion. The control animals received normal saline and an i.v. infusion. Liver function tests and analysis of serum, erythrocyte, and tissue malondialdehyde contents were performed at commencement of laparotomy, before reperfusion, and at 30 min and 7 days after reperfusion. Liver biopsies were taken at laparotomy, at 30 min, and at 7 days after reperfusion for histological and ultrastructural examination. Assessment of apoptosis included in situ end-labelling analysis and DNA gel electrophoresis. Survival at 7 days was better in the treated animals than in the controls (9/10 vs. 7/12). Tissue malondialdehyde content, aspartate aminotransferase, and lactate dehydrogenase levels were lower in the treatment group, in which morphological changes were significantly less evident than in the controls 30 min after reperfusion. At 7 days, differences between the groups with respect to cell integrity were apparent only on ultrastructural analysis. Glycogen content, 7 days after reperfusion, was higher in the treatment group than in the controls: 70.25 per cent vs. 21.66 per cent positive hepatocytes (score 3 vs. score 1). Multiparametric analysis showed fewer apoptotic cells in the treatment group at all times. Our data show that the administration of L-arginine reduces damage to liver tissue after ischaemia/reperfusion injury in a pig model. This may be explained not only by the known vasodilator, anti-aggregation, and superoxide inactivation effects of increased nitric oxide release, but possibly also by some other action of L-arginine, such as its influence on cellular metabolism.

Animals↗
PubMed1997

Ovariectomy in the rat induces a rapid increase in the urinary excretion of hydroxylysine glycosides and non-reducible crosslink residues.

The ovariectomized rat is the most commonly used animal model of human postmenopausal osteoporosis, exhibiting a high rate of bone turnover with resorption exceeding formation. At present, bone turnover is quantified directly by dynamic histomorphometry. The aim of the present study was to determine whether the measurement of the urinary output of some specific bone collagen catabolites--pyridinolines and hydroxylysine glycosides--could be used to indirectly monitor the initial phase of bone turnover increase in ovariectomized 90-day-old rats. Ninety-day-old female rats were randomly divided into three groups (n = 6): ovariectomized, sham-operated and non-treated controls. Urine samples (24 h) were collected 6 days before surgery and twice weekly for the 4 weeks following ovariectomy. Urinary excretion of pyridinoline (PYD), deoxypyridinoline (DPD), glucosyl-galactosyl-hydroxylysine (GGHYL) and galactosyl-hydroxylysine (GHYL) were measured. As expected, ovariectomy was associated with a significant decrease in bone mineral density in both the proximal tibial and distal femoral metaphysis. Compared with both sham-operated and control animals, ovariectomized rats showed significant increases in PYD, GGHYL, and GHYL urinary output 8 days after surgery and in DPD output after 15 days. These changes were maintained throughout the study. The results confirm that measurement of the urinary excretion of pyridinolines and hydroxylysine glycosides represents a powerful tool for detecting the onset of bone turnover in ovariectomized 90-day-old rats.

Amino Acids↗
PubMed1997

Surgical pathology of primary cardiac and pericardial tumors.

OBJECTIVE: Retrospective study of surgical pathology experience on cardiac and pericardial tumors at the University of Padua in the era of immunohistochemistry and endomyocardial biopsy. METHODS: In the period 1970-1995, we studied 125 bioptic primary neoplasms: specimens were obtained from surgical resection in 116 cases, heart transplantation in 3, pericardiectomy in 3, endomyocardial biopsy in 2 and thoracoscopic biopsy in 1. Tumor histotype was established by light microscopy and more recently by immuno-histochemistry, using a large panel of antibodies, through avidin-biotin peroxidase method, against factor VIII-related antigen, ulex-europaeus, desmin, myoglobin, muscle-specific actin, smooth muscle-specific actin, vimentin, cytokeratins, leukocytic common antigen, neurofilaments and S100-protein. RESULTS: One hundred and thirteen were benign neoplasms: myxoma was the most frequent (87 cases) followed by pericardial cyst (8), endocardial papilloma (5), fibroma (3), rhabdomyoma (3), hematic cyst (2), teratoma (2), hemangioma (1), celothelioma (1) and lipoma (1). Malignancy was diagnosed in 12 cases, and consisted of pericardial mesothelioma (3), myxosarcoma (3), angiosarcoma (2), fibrosarcoma (2) and leiomyosarcoma (2); 4 of them were intracavitary atrial masses and were supposed to be atrial myxoma on the clinical ground. Differential diagnosis included endocardial thrombosis (10), metastasis of concealed extracardiac tumors (5), echinococcosis (3), and Loeffler's fibroplastic endocarditis (3). In 4 cases, cardiac mass histotype was defined without thoracotomy, through endomyocardial (3) and thoracoscopic (1) biopsy. CONCLUSIONS: A large spectrum of cardiac tumors is observed in the surgical pathology practice. Although the diagnosis of cardiac masses is easily attainable by routine imaging techniques, differential diagnosis between primary and secondary tumors, malignant and benign forms, and non neoplastic masses, is achievable only by a thorough microscopic study of surgical resections. The role of the cardiac pathologist is becoming crucial as in other fields of oncology.

Adolescent↗
PubMed1997

Chronic isolated macrothrombocytopenia with autosomal dominant transmission: a morphological and qualitative platelet disorder.

We studied 47 subjects belonging to 13 unrelated families with a history of mild haemorrhagic diathesis and chronic thrombocytopenia. 36 patients presented some degree of thrombocytopenia: 7/36 (19%) had slight thrombocytopenia (100-150 x 10(9)/L); 26/36 (72%) had mild thrombocytopenia (50-100 x 10(9)/L) and 3/36 (8%) had severe thrombocytopenia (< 50 x 10(9)/L). No correlation was observed between platelet count and the degree of haemorrhagic diathesis, which was mild in the majority of patients. Transmission was autosomal dominant. Platelet anisocytosis, increased percentage of large platelets and absence of leukocyte inclusions were observed in 26/30 (87%) of the examined blood smears. The ultrastructural appearance of platelets was normal. Megakaryocytes appeared normal in number in 10/10 patients, but showed asynchronous nuclear-cytoplasm maturation and mainly nonlobulated nuclei. Platelet aggregation was studied in 26 patients and either increased or decreased curves were variably observed in response to different aggregating agents. Platelet-associated IgG (PAIgG) was increased in 18/31 (58%) patients, while serum autoantibodies against platelet glycoproteins Ib/IX or IIb/IIIa were demonstrable in only 1 case. An increased expression of platelet surface glycoproteins Ib and IIb/IIIa, as studied by murine monoclonal antibodies binding in 17 cases, was observed. Platelet survival performed by 111Inoxine-labelled autologous platelets was normal in the 3 studied patients. Congenital macrothrombocytopenia confirms to be a distinct clinical disorder for which the name of "chronic isolated hereditary macrothrombocytopenia" is proposed.

Adolescent↗
PubMed1997

Pancoast tumours: clinical assessment and long-term results of combined radiosurgical treatment.

BACKGROUND: Many oncologists have now accepted a combined radiosurgical approach as the treatment of choice in patients with Pancoast tumour but most reports show an incorrect assessment of the disease. METHODS: Stage III lung cancer was classified as Pancoast tumour if the pulmonary extent was limited to the upper apical segment and if at least one of the features of Pancoast syndrome, indicating tumour spread to the para-apical structures, was present. Between 1984 and 1988 15 consecutive patients were treated with primary radiotherapy followed by surgery or with primary excision and subsequent radiotherapy in the absence of an initial histological diagnosis. RESULTS: The mortality of patients given the combined treatment was 6.6% (one death due to pulmonary embolism), and the five year survival rate was 26.6% for all patients and 57% for those who underwent complete resection without N2 disease. Long-term survival was 0% for those cases with incomplete resection, N2 disease, or malignant invasion of the first rib. CONCLUSIONS: Stage III lung cancer, classified as Pancoast tumour according to strict, consistent criteria, is best treated by primary radiotherapy; combined treatment should be used only for patients with potentially resectable cancer without N2 disease and/or malignant invasion of the first rib.

Combined Modality Therapy↗
PubMed1997

Differences and intersubject variability of loudness discomfort levels measured in sound pressure level and hearing level for TDH-50P and ER-3A earphones.

Loudness discomfort levels (LDLs) were measured in dB HL and SPL at discrete frequencies between 500 to 4000 Hz on 31 hearing-impaired ears using TDH-50P and ER-3A earphones. The results revealed no significant differences in the measured sound pressure level (SPL) between the two earphones at all test frequencies. However, with dB HL measurements, statistically significant differences were revealed at 1500 and 4000 Hz between earphone conditions. The results also revealed large intersubject differences in the measured LDL (HL and SPL) for both earphones. The results of this study highlight the difficulty in accurately predicting individual performance from averaged group data.

Correction of Hearing Impairment↗