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Biomedical subjects

F Silvestri

Publications and source records attributed to F Silvestri.

At least 19 recordsLinked to original sources
PubMed2004

Cyclo-oxygenase-2 (COX-2) expression at the site of recent myocardial infarction: friend or foe?

BACKGROUND: Cyclo-oxygenase-2 (COX-2) is induced in cardiomyocytes only in response to stress, such as ischaemia. OBJECTIVE: To assess COX-2 expression at the site of recent myocardial infarction. METHODS: COX-2 expression was evaluated by specific immunostaining in cardiomyocytes from 23 subjects who died 10-60 days after acute myocardial infarction. The relation between COX-2 myocardial expression and apoptotic rate was investigated. Cardiomyocyte apoptotic rate was defined as the number of cells co-expressing in situ end labelling of DNA fragmentation (TUNEL) and immunostaining for activated caspase-3. RESULTS: COX-2 expression was found in cardiomyocytes at the site of infarction in nine of 23 cases (39%). It was associated with fivefold higher apoptotic rates (median 17.9% (interquartile range 11.0-25.4%) v 3.7% (0.6-12.8%); p = 0.016), and apoptotic rate increased progressively from mild to intense COX-2 staining (p for trend 0.009). COX-2 expression co-localised with TUNEL nuclear staining in myocytes, and there was a high concordance between COX-2 and hypoxia induced factor 1-alpha staining (78%, p = 0.021) and between COX-2 and bax (83%, p = 0.014). Subjects showing myocardial COX-2 expression were more likely to have enlarged hearts (p = 0.050), and intense COX-2 staining was strictly associated with symptomatic heart failure (p = 0.035). CONCLUSIONS: COX-2 is expressed in cardiomyocytes in nearly 40% of cases at the site of recent acute myocardial infarction, even late after the index event. Its expression was associated with extremely high apoptotic rates. These findings suggest a potential cause-effect link between COX-2 expression and enhanced myocardial apoptosis in ischaemic cardiomyopathy.

Aged↗
PubMed2003

High-risk clinical features predict increased post-infarction myocardial apoptosis and the benefits as a result of an open infarct-related artery.

BACKGROUND: Infarct-related artery (IRA) patency after acute myocardial infarction (AMI) is associated with a more favourable clinical course, in particular in patients with high-risk features. As it has been recently reported that IRA patency is associated with a reduced postinfarction apoptotic rate (AR), the aim of our study was to assess whether IRA status late after AMI had a different impact on AR in high- vs. low-risk patients. METHODS AND RESULTS: Co-localization of TUNEL and caspase-3 was used to calculate the AR at the site of infarction at the time of death in 30 subjects. The Norris coronary prognostic index (NI) was calculated (computing age, presence of pulmonary congestion, heart size and history of previous additional AMI) in order to define the patients' individual risk at the time of hospitalization. According to the NI (< or =7 vs. >7), subjects were divided into low and high risk, as NI >7 carries an approximate threefold higher risk of death. The NI was significantly correlated with the AR at the time of death both in infarct and remote areas. Twenty subjects had IRA occlusion at the time of death, and in these patients AR was significantly higher both in infarct and remote areas (P<0.001 and P=0.009 vs. the others, respectively). However the impact of IRA occlusion on AR was significantly different comparing high- vs. low-risk subjects. In particular, AR at the infarct site was 10-fold higher in the high-risk subjects with IRA occlusion (26.1%[20.4-28.7%]) vs. those with open IRA (2.3%[0.6-3.5%]; P=0.002) and was nonsignificantly different in the low-risk subjects vs. those without IRA occlusion (8.2%[2.5-17.5%] vs. 5.4%[1.5-7.9%]; P=0.48). Similarly, in the high-risk subjects, AR in remote areas was significantly greater in cases with occluded vs. open IRA (0.7%[0.4-0.9%] vs. 0.3%[0.3-0.32%]; P=0.009). CONCLUSION: A significantly higher AR is associated with IRA occlusion late post AMI in subjects with high-risk clinical features, and not in low-risk patients. The diverse impact of IRA occlusion on AR in subjects with different risk profiles may explain the greater benefit associated with coronary reperfusion in high-risk subjects. The overall lower AR in low-risk subjects, independently from the IRA status, may be correlated with the better long-term prognosis after AMI in this case.

Aged↗
PubMed2003

Fusobacterium nucleatum: a rare cause of bacteremia in neutropenic patients with leukemia and lymphoma.

Although anaerobic bacteremias are uncommon in oncohematologic patients, nevertheless they have been considered an emergent problem in the last few years. Fusobacterium nucleatum is an anaerobic Gram-negative bacillus commonly present in the oral cavity and in the respiratory and genito-urinary tracts. Over a 10-year period 18 episodes of F. nucleatum bacteremia in patients with hematological malignances (15 leukemias and 3 lymphomas) have been observed in our Department of Hematology. Predisposing factors included oropharyngeal mucositis and severe neutropenia owing to intensive chemotherapy. In our experience no septic shock occurred and the outcome of bacteremias caused by F. nucleatum was favorable.

Adolescent↗
PubMed2003

Right ventricular dilatation after left ventricular acute myocardial infarction is predictive of extremely high peri-infarctual apoptosis at postmortem examination in humans.

BACKGROUND: Cardiac remodelling after acute myocardial infarction (AMI) is characterised by molecular and cellular mechanisms involving both left and right ventricles, and biventricular failure identifies patients with an extremely unfavourable prognosis. AIMS: To assess whether a link exists between increased myocardial apoptotic rates (AR) at sites of recent infarction and patterns of unfavourable cardiac remodelling, such as biventricular enlargement after left ventricular (LV) infarction. METHODS: Twelve patients with recent AMI involving the LV and not the right ventricle (RV) and with permanent infarct related artery occlusion were selected at necropsy. Gross pathological characteristics, such as LV and RV dilatation, and AR at site of infarction were assessed. Potential false positive results (DNA synthesis and RNA splicing) were excluded from the cell count. RESULTS: RV enlargement, defined as a tricuspidal ring greater than 120 mm, was found in five cases and was associated with LV dilatation. These patients showed significantly higher AR than the others. When the subjects were divided into three groups according to progressive cardiac remodelling (absence of cardiac dilatation, isolated LV dilatation, and biventricular enlargement), the last group had significantly higher ARs than the other two groups, showing that myocardiocyte apoptosis is increased in more unfavourable forms of cardiac remodelling. CONCLUSION: Patients with severely unfavourable cardiac remodelling, such as biventricular enlargement, have extremely high myocardiocyte apoptosis at necropsy, even late after LV myocardial infarction, supporting the role of myocardiocyte loss in determining post-infarction adverse remodelling.

Aged↗
PubMed2002

[The Pathology museum of Trieste. From medical arachaeology to revitalization].

Abandoned in the attic of Trieste's Ospedale Maggiore--which since 1872 housed the hospital's Department of Pathological Anatomy, then known as the Prosettura--is a "museum" of pathology that comprises a heterogeneous collection of anatomic specimens: traumatic, inflammatory and neoplastic lesions, as well as specimens of tattooed skin and hymens. All this material, most of which dates back to the end of the nineteenth and to the start of the twentieth century, will soon be recovered and displayed in a museum. Because this operation has given rise to an interesting discussion on the very significance--both present and past--of this kind of museum, we believe it necessary to extend the debate to those in charge of similar collections and to all our colleagues in the medical profession. It is our opinion that this operation may be justified and meaningful, provided that each specimen is presented with adequate reference to its historical and scientific context.

History, 19th Century↗
PubMed2001

Meningeal and cerebral involvement in multiple myeloma patients.

Cerebral involvement is an unusual complication in multiple myeloma: herein four patients who presented myelomatous meningitis with multiple intraparenchymal lesions or a localized cerebral plasmacytoma are described. Two of these patients relapsed with meningeal involvement and a very limited disease outside the central nervous system after an initial complete remission obtained with induction chemotherapy. In the other two cases, the cerebral tumor appeared during first-line treatment. Cytological examination of the cerebrospinal fluid and magnetic resonance were essential for diagnosis. Different modalities of treatment were used, including intrathecal chemotherapy, cranial irradiation, and systemic chemotherapy with high-dose methotrexate and cytarabine, achieving improvement of neurological symptoms in three of four patients.

Aged↗
PubMed2001

Evidence that human cardiac myocytes divide after myocardial infarction.

BACKGROUND: The scarring of the heart that results from myocardial infarction has been interpreted as evidence that the heart is composed of myocytes that are unable to divide. However, recent observations have provided evidence of proliferation of myocytes in the adult heart. Therefore, we studied the extent of mitosis among myocytes after myocardial infarction in humans. METHODS: Samples from the border of the infarct and from areas of the myocardium distant from the infarct were obtained from 13 patients who had died 4 to 12 days after infarction. Ten normal hearts were used as controls. Myocytes that had entered the cell cycle in preparation for cell division were measured by labeling of the nuclear antigen Ki-67, which is associated with cell division. The fraction of myocyte nuclei that were undergoing mitosis was determined, and the mitotic index (the ratio of the number of nuclei undergoing mitosis to the number not undergoing mitosis) was calculated. The presence of mitotic spindles, contractile rings, karyokinesis, and cytokinesis was also recorded. RESULTS: In the infarcted hearts, Ki-67 expression was detected in 4 percent of myocyte nuclei in the regions adjacent to the infarcts and in 1 percent of those in regions distant from the infarcts. The reentry of myocytes into the cell cycle resulted in mitotic indexes of 0.08 percent and 0.03 percent, respectively, in the zones adjacent to and distant from the infarcts. Events characteristic of cell division--the formation of the mitotic spindles, the formation of contractile rings, karyokinesis, and cytokinesis--were identified; these features demonstrated that there was myocyte proliferation after myocardial infarction. CONCLUSIONS: Our results challenge the dogma that the adult heart is a postmitotic organ and indicate that the regeneration of myocytes may be a critical component of the increase in muscle mass of the myocardium.

Antibodies, Monoclonal↗
PubMed2001

Long-lasting complete remission of hepatitis C virus (HCV) infection and HCV-associated immunocytoma with alpha-interferon treatment.

Several epidemiological data suggest the involvement of hepatitis C virus (HCV) in the pathogenesis of some histotypes of B-cell non-Hodgkin's lymphomas, in particular immunocytoma. We report a patient with HCV-associated immunocytoma, first treated with six courses of fludarabine. A partial response was achieved and subsequent therapy with alpha-interferon resulted in the clearance of the virus and a long-lasting complete clinical and histological remission of the lymphoproliferative disease.

Adult↗
PubMed2001

Absence of connections between spinal nerves and the spinal cord in a twin fetus: a very rare malformation occasionally evidenced at autopsy.

We describe a rare case of spinal cord malformation in a dichorionic diamniotic twin fetus aborted at 20 weeks' gestation due to acute chorioamnionitis with placental dysmaturity probably caused by a maternal viral infection. At autopsy, there were no connections between the spinal nerves and the spinal cord. The spinal cord lacked the posterior median fissure and gray matter; only a few neurons were present in the anterior and lateral gray columns. No chromosome anomalies were found. Although we cannot reconstruct the pathogenetic chain of events leading to this malformation, we believe that it is correlated with a maternal viral infection. We hypothesize that this viral infection altered the delicate balance between the factors inducing and those inhibiting fetal spinal neural differentiation.

Abortion, Spontaneous↗
PubMed2000

Short-TE projection reconstruction MR microscopy in the evaluation of articular cartilage thickness.

The aim of this study was to assess the potential of projection-reconstruction (PR) MR microscopy in the accurate measurement of cartilage thickness. Short-TE PR microimages were acquired at 7.05 T on bone-cartilage cylindrical plugs excised from four regions of two disarticulated femoral heads (i. e. superior, inferior, posterior and anterior), using an NMR instrument equipped with a microimaging accessory. The PR microimages were then correlated with conventional spin-echo (SE) microimages and with histology. On PR microimages, acquired with an echo time of 3.2 ms, the cartilage signal was increased, allowing an accurate delineation of the cartilage from the tidemark/cortical bone region. As a consequence, by the PR method a more precise measurement of cartilage thickness compared with that performed by the conventional SE approach was feasible. An excellent correlation between PR microimages and histology was also obtained (r = 0.90). By the proposed method it is possible to accurately determine the cartilage thickness better than with the conventional SE sequences.

Aged↗
PubMed2000

Hepatitis c and lymphoma.

Epidemiologic data presented in this review suggest the involvement of hepatitis C virus (HCV) in the patho- genesis of some histotypes of B-cell non-Hodgkin's lymphoma, in particular immunocytoma and lymphomas growing primarily in the liver and major salivary glands. Experimental data further support this hypothesis. Recent findings include demonstration that patients with hematologic malignancies can be treated safely with standard and high-dose chemotherapy even in the presence of HCV infection.

Animals↗
PubMed2000

Articular cartilage repair in rabbits by using suspensions of allogenic chondrocytes in alginate.

The feasibility of allogenic implants of chondrocytes in alginate gels was tested for the reconstruction in vivo of artificially full-thickness-damaged articular rabbit cartilage. The suspensions of chondrocytes in alginate were gelled by the addition of calcium chloride solution directly into the defects giving in situ a construct perfectly inserted and adherent to the subchondral bone and to the walls of intact cartilage. The tissue repair was controlled at 1, 2, 4 and 6 months after the implant by NMR microscopy, synchrotron radiation induced X-ray emission to map the sulfur of glycosaminoglycans and by histochemistry. Practically a complete repair of the defect was observed 4-6 months from the implant of the chondrocytes with the recovery of a normal tissue structure. Controls in which Ca-alginate alone was implanted developed only a fibrous cartilage.

Alginates↗
PubMed2000

Wound closure technique and acute wound complications in gastric surgery for morbid obesity: a prospective randomized trial.

BACKGROUND: During the past 10 years, numerous clinical studies have supported the use of continuous monofilament fascial closure after laparotomy. Because of the increased incidence of surgical-site infections and other acute wound complications in the morbidly obese, these patients are well suited for a study of technical factors that may affect the frequency of these wound complications. STUDY DESIGN: A prospective, randomized study of the midline fascial closure technique in gastric bariatric operations was conducted between 1991 and 1998 in 331 consecutive morbidly obese patients. At the time of closure of the upper midline laparotomy wound, the patients were randomized into two groups: Group I patients (n = 172) underwent continuous fascial closure and group II patients (n = 159) underwent interrupted fascial closure. All patients received prophylactic antibiotics in a similar fashion. Wounds were monitored for 30 days postoperatively, and acute wound complications were classified as superficial or deep. Superficial complications included superficial surgical-site infections, seromas, and hematomas. In all superficial complications, the fascia remained uninvolved and intact. Deep wound complications included deep surgical-site infections and fascial dehiscence. RESULTS: A total of 49 acute wound complications occurred (15%). There were 22 superficial (7%) and 27 deep (8%) wound complications in the 331 in the patients studied. Group I patients experienced fewer total wound complications than group II patients (18 versus 31; p=0.021). Group I patients also experienced fewer deep wound complications than group II (5 versus 22; p = 0.003). CONCLUSIONS: Continuous fascial closure reduces major acute wound complications in morbidly obese patients undergoing gastric operations for obesity.

Cholecystectomy↗