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Biomedical subjects

S Schena

Publications and source records attributed to S Schena.

17 recordsLinked to original sources
PubMed2001

Pyruvate inhibits hepatic ischemia-reperfusion injury in rats.

BACKGROUND: Ischemia/reperfusion (I/R) injury is a limiting factor in liver transplantation. We have recently shown that pyruvate (PY) inhibits intestinal and renal I/R injury. This study aims to evaluate the protective effect of PY on hepatic I/R injury. METHODS: ACI rats were treated with PY, whereas control animals received placebo. Rats were killed after 60 min of partial hepatic ischemia and after 2, 6, 24, and 48 hr of reperfusion. For each time point, serum aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase were measured, and liver biopsy specimens were obtained to evaluate morphology, DNA fragmentation, and apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling). RESULTS: The survival rate 48 hr after I/R was 83% in the control group, and 100% in the PY-treated group (P>0.05). Increased enzymatic levels and histologic findings showed increased liver damage in the untreated group compared with PY. In control rats, apoptosis was enhanced after 1 hr of ischemia and peaked after 2 hr of reperfusion, to decrease gradually 48 hr after reperfusion; in the PY group apoptosis was delayed and reduced. After 1 hr of ischemia, the number of apoptotic nuclei was significantly increased in control livers compared with normal preischemic livers, whereas the number was significantly reduced by PY. After 2 hr of reperfusion, the maximum number of apoptotic cells was observed, whereas PY significantly reduced the amount of apoptotic cells (P<0.05). Apoptosis was delayed in PY-treated livers to 6 hr after reperfusion, peaking at a significantly lower count compared with placebo-treated controls (P<0.05). CONCLUSION: These data indicate that PY has a protective effect on I/R injury of the liver.

Animals↗
PubMed2001

Early assessment of apoptosis in isolated islets of Langerhans.

BACKGROUND: There is substantial evidence to link early graft loss after islet transplantation to isolation-induced islet cell apoptosis. Measurement of caspase 3 activity and detection of the lost cell membrane asymmetry, revealed by annexin V binding, are newly available assays that allow the analysis of early events of apoptosis. METHODS: In this study, we compared these tests with the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay and analysis of DNA fragmentation after gel electrophoresis in freshly isolated islets obtained from rats, before and after treatment with interleukin-1 beta, interferon gamma, and tumor necrosis factor a, cytokines known to induce islet cell damage. RESULTS: A measurable level of apoptosis was observed the day after isolation when caspase 3 activity and annexin V binding were used as assays, although no substantial DNA fragmentation was detected with TUNEL assay and DNA gel electrophoresis. Baseline caspase 3 activity was 0.8+/-0.3 U/100 islet equivalents and it increased to 1.4+/-0.45 U/100 islet equivalents 3 hr after cytokine stimulation (P<0.05 vs. unstimulated islets). The baseline level of apoptosis, as detected by annexin V binding, was 21.1%+/-5.8%, and it increased to 27.5%+/-8.1% 6 hr after addition of the cytokine cocktail (P<0.01 vs. unstimulated islets). An increase in the number of TUNEL-positive nuclei was detected 24 hr after stimulation and peaked at 48 hr. DNA laddering was also evident 24 hr after cytokine treatment. CONCLUSION: These data suggest that measurement of caspase 3 activity and annexin V binding analysis might represent reliable markers of early events of islet cell apoptosis.

Animals↗
PubMed2001

Endovascular stent-graft treatment for diseases of the descending thoracic aorta.

OBJECTIVE: Assessment of endovascular stent-graft treatment for diseases of the descending thoracic aorta as a valid and effective alternative to surgery. METHODS: From March 1999 to August 2000, a total of 16 patients underwent deployment of endovascular stent-grafts in the descending thoracic aorta. Patients were divided into three groups according to the type of lesion. Group A (n=8) included five patients with atherosclerotic aneurysm and three with chronic post-traumatic pseudoaneurysm. Patients with acute post-traumatic pseudoaneurysm (n=3) and type B aortic dissection (n=5) were included in Groups B and C, respectively. All patients underwent 5-mm chest spiral angio-computerized tomography (CT) scan and angiography as preoperative assessment. The deployed stent-graft systems were Talent-Medtronic and Excluder-Gore. RESULTS: A total of 20 stent-grafts were placed. Two patients required deployment of two grafts, while three grafts were juxtaposed in a third patient in order to treat larger lesions. There was no mortality related to the procedure, although one patient (6.2%) died because of multiorgan failure 24h post-operatively. The placement of the graft was successful in all cases except one affected with type B dissection and characterized by a very large intimal flap, which was eventually fenestrated by graft guidewire. Therefore, an optimal sealing of the grafts was achieved in 15 patients. However, in one patient the descending aorta had to be surgically replaced because of the calcified pseudoaneurysm still compressing the trachea and left bronchus. Two patients required a left carotid-subclavian by-pass in order to achieve a sufficient neck for the proximal placement of the graft. No spinal cord injuries were observed. At the follow-up, performed with chest spiral angio-CT scan within 72 h and scheduled at 6 and 12 months and once a year, no stent-graft related complications have been detected. CONCLUSIONS: Endoluminal stent-graft treatment may represent a valid option in well-selected cases of descending thoracic aorta diseases. A longer follow-up in a larger series of patients is desirable to confirm these initial positive results.

Adolescent↗
PubMed2000

FK409, a spontaneous nitric oxide releaser, attenuates allograft vasculopathy in a rat aortic transplant model.

Although systemic administration of NO donors has been shown to attenuate the development of neointimal hyperplasia in the balloon injury model, this strategy has not been tested in a model of allograft vasculopathy. In this study, we investigated the effect of FK409, a spontaneous NO releaser, on the development of allograft vasculopathy, using a rat aortic transplant model. Thoracic aortas from ACI rats were transplanted heterotopically into the abdominal aorta of Wistar-Furth rats. Postoperatively, recipients received FK409 orally every 8 hours from the day of transplantation to the time of euthanization. Morphometric and immunohistochemical analyses were performed on the aortic grafts 8 weeks after transplantation. Control allografts showed severe neointimal hyperplasia, which consists mainly of alpha-actin-containing vascular smooth muscle cells. The FK409-treated allografts showed a dose-dependent reduction (statistically significant compared with the control) in the neointimal thickness as the dose increased from 1 to 10 mg/kg (thrice per day). However, there was no significant difference in the neointimal thickness between groups treated with 10 and with 20 mg/kg. FK409 treatment (10 mg/kg) caused a significant decrease in DNA synthesis (5-bromo-2-deoxyuridine [BrdU] uptake), an increase in DNA fragmentation (terminal deoxynucleotidyltransferase-mediated uridine nick-end labeling [TUNEL]), and upregulation of Fas expression, in the neointimal vascular smooth muscle cells. These data suggest that FK409 attenuates the allograft vasculopathy in a rat aortic transplant model.

Animals↗
PubMed2000

Multicystic kidney dysplasia and Turner syndrome: two cases and a literature review.

Renal malformations occur in 33%-70% of cases of Turner syndrome (chromosome 45 and variants). We describe two cases of multicystic dysplastic kidney in Turner syndrome. A literature review of renal abnormalities in Turner syndrome shows the frequency of cystic disease to be 1.76%. In multicystic dysplastic kidney, diagnostic investigation of the contralateral kidney, including voiding cystourethrography, is necessary in view of the high incidence of associated diseases (15%-20% of cases, vesicoureteric reflux) and other anomalies.

Female↗
PubMed2000

Inflammatory response and angiogenesis after percutaneous transmyocardial laser revascularization.

BACKGROUND: The aim of our study was to investigate the inflammatory response immediately after percutaneous transmyocardial laser revascularization (PTMR) along with the underlying mechanism of angiogenesis. METHODS: Patients with angina pectoris underwent coronary angiography and were divided into two groups. Group A (n = 10) included patients with obstructed vessels who received PTMR, whereas group B (n = 5) comprised patients who had normal coronary arteries. Blood levels of neutrophils, procalcitonin, troponin-I, myoglobin, and creatine kinase (CK) mass were evaluated in each patient before angiography and monitored up to 48 hours after the procedure. Six patients were injected with 99mTc-leukoscan approximately 60 to 90 minutes after PTMR. During the 240 to 300 minutes after the radionuclide administration, single photon emission tomography (SPET) was performed and compared with conventional 99mTc-sestamibi-SPET. RESULTS: A significant increase in blood levels of neutrophils and procalcitonin was observed in group A only (p < 0.005). A slight but significant increase of troponin-I was evident in the same group (p < 0.05), and a distinct myocardial uptake of 99mTc-Leukoscan-SPET was observed in each patient along homologous regions treated by PTMR. CONCLUSIONS: The increased amount of neutrophils (both circulating and inside the treated myocardial areas) along with the raised levels of procalcitonin were the immediate reactions to PTMR. This systemic and intramyocardial inflammatory response is the underlying mechanism that gives rise to angiogenesis.

Antibodies, Monoclonal↗
PubMed2000

Instrumental validation of percutaneous transmyocardial revascularization: follow-up data at one year.

BACKGROUND: Despite the clinical efficacy of percutaneous transmyocardial revascularization (PTMR), up to date there are still no instrumental validations to demonstrate both the improved perfusion of treated areas and cardiac function. METHODS: During the first year of follow-up after PTMR, 27 patients (group A) underwent 99mTc MIBI exercise-single photon emission tomography (SPET), while 30 patients (group B) underwent serial transthoracic echocardiography (TTE) evaluations with analysis of cardiac volumes and subendocardial layer thickness in systole. RESULTS: All 57 patients had a significant angina Canadian Cardiovascular Society (CCS) class improvement. Group A patients (75%) had improved exercise-SPET perfusion in treated areas at 12 weeks after PTMR, and at the next follow-up. Group B patients had non-significant reduction in global volume and no significant change in ejection fraction. However, there was an improvement in thickness of the subendocardial-treated areas in systole that persisted during follow-up. CONCLUSIONS: The use of SPET and TTE validates the clinical efficacy of PTMR.

Aged↗
PubMed2000

Distribution of food intake as a risk factor for childhood obesity.

OBJECTIVE: The purpose of our study was to assess the relationship between nutrient intake, partitioning of food intake, parents' overweight and adiposity in a group of children. SUBJECTS: 530 7-11-year-old children: 278 males, 252 females. METHODS: Energy intake, nutrient intake and percentage distribution of the intake of energy among the different meals were assessed by means of diet history. Body composition was obtained by measuring skinfold thickness. RESULTS: We identified the relationship between the children's adiposity and their parents' body mass index (BMI) mother: r=0.12, P<0.01; father: r=0.13; P<0.01), carbohydrate (r=-0. 15, P<0.001) and fat intake (r=0.14, P<0.002), and the proportion of energy taken at dinner (r=0.1, P<0.05). A multiple regression analysis was run with a stepwise procedure using relative adiposity as the dependent variable and parents' BMI, dinner intake (percentage of energy intake), EI/BMR ratio (an index of energy intake validity), and sex (dummy variable) as independent variables. All the independent variables, except percentage of fat intake, were included in the final model. The equation was able to explain approximately 19% (R=0.44, P<0.001) of inter-individual fat mass percentage variability. CONCLUSIONS: Diet composition did not contribute to explain the children's adiposity when the parents' overweight (BMI) was taken into account. However, the percentage distribution of the intake of energy among the different meals, particularly at dinner, contributed to explain inter-individual variance of fatness in children of both sexes. International Journal of Obesity (2000)24, 75-80

Body Composition↗
PubMed2000

Survival following treatment of a cardiac malignant fibrous histiocytoma.

The authors report the successful surgical and chemotherapeutic management of a malignant fibrous histiocytoma with localization in the heart. This rare malignancy has specific morphologic characteristics and is diagnosed in adults when it is already locally aggressive or metastasized. The average survival time for patients with malignant fibrous histiocytoma is < 12 months. Neither clinical nor instrumental signs of recurrence have been detected in this patient after an aggressive surgical resection and a specific therapeutic approach.

Aged↗
PubMed1999

One step surgical repair of type II acute aortic dissection and aortic coarctation.

It is presented the case of acute type II aortic dissection in a patient with aneurysmal ascending aorta, hypoplastic arch and isthmic coarctation. One single step replacement of the ascending aorta, arch and the isthmus was performed by ensuring simultaneous optimal perfusion above and below the coarctation through the femoral and subclavian artery.

Abnormalities, Multiple↗
PubMed1997

Asymptomatic large left-atrial ball thrombus. Secondary to mitral stenosis.

We describe the very unusual case of a patient with a large, free-floating left-atrial thrombus secondary to severe mitral stenosis, in whom the peculiar symptoms and complications of a ball thrombus were absent. The patient's only symptom before the episode reported here was mild dyspnea, which was attributed to mitral stenosis. She experienced neither embolism nor syncope. While even her clinical signs did not indicate a left-atrial ball thrombus, both echocardiography and angiography showed a free-floating thrombus. Because of the risk of stroke and acute obstruction of the mitral valve, emergency surgery was performed upon diagnosis of the ball thrombus. The surgery, which consisted of removing the thrombus and replacing the mitral valve with a mechanical prosthesis, was uneventful. A computed tomographic brain scan prior to discharge did not detect any cerebral infarction.

Aged↗
PubMedDate not supplied

Hypoxic reperfusion limits functional impairment following cardioplegic arrest in isolated rat heart.

BACKGROUND: Reperfusion injury decreases both systolic contractility and diastolic compliance. Several studies indicate that the sustained decrease in diastolic compliance is mainly due to reactive oxygen intermediates (ROI) generation and calcium overload. METHODS: Male Wistar isolated rat hearts were divided into 2 groups (n=10 each), perfused according to Langendorff technique and exposed to 45 min of ischemia. Hearts belonging to the first group were reperfused with Krebs-Henseleit solution at 600 mmHg pO2; a 150 mmHg pO2 perfusate was utilized in the second group during the first minute and switched to 600 mmHg pO2 thereafter. Modifications in diastolic compliance and systolic contractility were assessed by changes in left ventricular end-diastolic (LVEDP) and developed pressure (LVDP), and first derivative of the pressure curve (dP/dt). RESULTS: Increase in LVEDP values, with respect to pre-ischemic data, were detected at 1, 5, 10, 20 min following reperfusion at 600 mmHg pO2, and were respectively: +40.17+/-18.61, +57.5+/-28.8, +59.8+/-30.5 and +63.2+/-34.1 mmHg. At 150 mmHg pO2 they were: +15.69+/-13.13, +22.4+/-14.1, +26.2+/-13.7 and +28.9+/-15.8, with a significant difference within the first 20 min (p<0.05). At high pO2 levels, LVDP decreased of 53.0+/-27.35, 60.5+/-22.6, 59.8+/-23.3 and 50.7+/-25.0 mmHg, versus 42.7+/-25.7, 38.0+/-29.5, 39.2+/-30.9 and 38.7+/-32.7 mmHg at lower pO2 (p=NS). The correspondent values of the dP/dt were 37.8+/-27.7, 30.1+/-17.2, 32.2+/-13.6 and 35.4+/-14.0% of pre-ischemic values at high pO2, versus 43.3+/-27.09, 51.9+/-25.1, 50.1+/-24.6 and 53.1+/-29.9% at lower pO2. Statistical significance was lower for LVDP and dP/dt than LVEDP. CONCLUSIONS: Diastolic functional impairment was partially reduced within the first 20 min following low pO2 reperfusion, but without any significant improvement of contractility.

Animals↗