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Biomedical subjects

L Zannini

Publications and source records attributed to L Zannini.

At least 19 recordsLinked to original sources

Clinical evaluation of oxidative stress and myocardial reperfusion injury in pediatric cardiac surgery.

BACKGROUND: To evaluate oxidative stress and myocardial damage after aortic crossclamping release (ACCR) during cardio pulmonary bypass (CPB) in children two parameters were investigated: total glutathione (GSH) and its oxidoreductive reactions (GSH/GSSG) as expression of oxidative stress, and plasmatic turnover of myocardial taurine (TAU) as expression of cell damage. METHODS: The study was divided in two periods: 1) first period: analysis of oxidative stress and myocardial damage in 18 children. 2) Second period: evaluation of myocardial cell protection by controlled anterograde low oxygen warm reperfusion (ALOWR) before declamping. Twenty-one children were divided in two groups: not receiving (Group 1, 9 patients) and receiving (Group 2, 12 patients) ALOWR. RESULTS: In the first period GSH values increased significantly after onset of mechanical ventilation (MV) in vein, after CPB start in artery and after ACCR in coronary sinus. Moreover TAU turnover in aortic and coronary sinus blood increased significantly after ACCR. In the second period, Group 2 showed a lower oxidative stress after ACCR, while no differences were observed in TAU turnover. CONCLUSIONS: 1) Assessment of TAU and GSH levels can be considered a good method to clinically evaluate myocardial injury during cardiac surgery. 2) MV and CPB can induce oxidative stress before aortic clamping and can decrease the physiologic scavengers. Therefore, to prevent that depletion, the strategy of these techniques must be adapted to the patient and to his cardiac disease. 3) Intramyocardial TAU turnover is not significantly modified by the reperfusion technique. 4) ALOWR can reduce myocardial oxidative stress and can improve heart recovery after the cardioplegic arrest.

Cardiopulmonary Bypass↗

Giving bad news: a GPs' narrative perspective.

The purpose of this study was to explore GPs' perspectives on giving bad news during consultations. To this end, 168 GPs were asked to recall, and record on the first page of a questionnaire, an occasion when they had given medically related bad news to a patient. The stories were analysed with a qualitative and interpretative approach. Two axes, each with a semantic polarity, were identified: a relational axis (semantic polarity: escape vs accompanying) and an ethical axis (semantic polarity: the doctor's choice vs the patient's choice). Furthermore, two main topics appeared to be common to almost all the narratives: the need to reassure the patient and the account of the doctor's emotions. Two different relational patterns appear to be described by doctors. A substantial number of GPs implicitly describe a disease- or doctor-centred consultation: in these cases the physicians refer to signs and symptoms, diagnosis and treatments; they decide for themselves whether to tell the truth or not. On the other hand, a smaller number describe consultations that could be defined as patient centred: these doctors consider that their duty of care for the individual ill person is paramount and try to respect the patient's right to decide. In both these relational patterns, GPs feel it is a fundamental professional duty to reassure the patient; furthermore, they feel the most difficult aspect is managing their own emotional responses.

Adult↗

Chk2 activation dependence on Nbs1 after DNA damage.

The checkpoint kinase Chk2 has a key role in delaying cell cycle progression in response to DNA damage. Upon activation by low-dose ionizing radiation (IR), which occurs in an ataxia telangiectasia mutated (ATM)-dependent manner, Chk2 can phosphorylate the mitosis-inducing phosphatase Cdc25C on an inhibitory site, blocking entry into mitosis, and p53 on a regulatory site, causing G(1) arrest. Here we show that the ATM-dependent activation of Chk2 by gamma- radiation requires Nbs1, the gene product involved in the Nijmegen breakage syndrome (NBS), a disorder that shares with AT a variety of phenotypic defects including chromosome fragility, radiosensitivity, and radioresistant DNA synthesis. Thus, whereas in normal cells Chk2 undergoes a time-dependent increased phosphorylation and induction of catalytic activity against Cdc25C, in NBS cells null for Nbs1 protein, Chk2 phosphorylation and activation are both defective. Importantly, these defects in NBS cells can be complemented by reintroduction of wild-type Nbs1, but neither by a carboxy-terminal deletion mutant of Nbs1 at amino acid 590, unable to form a complex with and to transport Mre11 and Rad50 in the nucleus, nor by an Nbs1 mutated at Ser343 (S343A), the ATM phosphorylation site. Chk2 nuclear expression is unaffected in NBS cells, hence excluding a mislocalization as the cause of failed Chk2 activation in Nbs1-null cells. Interestingly, the impaired Chk2 function in NBS cells correlates with the inability, unlike normal cells, to stop entry into mitosis immediately after irradiation, a checkpoint abnormality that can be corrected by introduction of the wild-type but not the S343A mutant form of Nbs1. Altogether, these findings underscore the crucial role of a functional Nbs1 complex in Chk2 activation and suggest that checkpoint defects in NBS cells may result from the inability to activate Chk2.

Cell Cycle↗

[Circulation support in left thoracotomy for descending thoracic aorta diseases in pediatric patients].

BACKGROUND: Complications of surgery of the descending thoracic aorta could include neurological problems such as paraparesis and paraplegia. Intestinal ischemia and acute renal failure could occur, too. During the cross-clamping time, the perfusion of the distal aorta by means of extracorporeal circulatory assistance can be useful to protect the spinal cord and the splanchnic organs and to reduce the incidence of these untoward events. The aim of this study was to verify the efficacy and suitability of this type of circulatory assistance in a pediatric age group. METHODS: From January 1996 to March 2000, in the Pediatric Cardiac Surgery Department of the Gaslini Institute (Genoa, Italy), 6 patients (mean age 39 months, mean weight 14.4 kg) were treated using extracorporeal circulatory assistance through the left thoracotomy. Indications for surgery included the removal of a migrated device previously inserted in order to close a patent ductus arteriosus in 1 patient, recurrent coarctation in 2 patients, and native coarctation with a poor collateral circulation in 3 patients. RESULTS: The early and late mortality rates as well as the morbidity rates (both neurological and splanchnic) were nil. CONCLUSIONS: Extracorporeal circulatory assistance can be helpful in pediatric patients and it can prevent neurological and renal injuries in cases of a) coarctation of the aorta with a poor collateral circulation and low distal pressure (< 40 mmHg during aortic occlusion); b) recoarctation with complex anatomy; c) other pathologies requiring prolonged descending thoracic aorta cross-clamping.

Aorta, Thoracic↗

Giant aneurysm following coil occlusion of patent ductus arteriosus.

A case is described in which a giant aneurysm developed following successful PDA coil occlusion in an infant with Marfan syndrome. This rare and severe complication brings into question the need for careful evaluation of these children before and after transcatheter occlusion.

Coronary Aneurysm↗

SEL1L, the human homolog of C. elegans sel-1: refined physical mapping, gene structure and identification of polymorphic markers.

We have cloned the human full-length cDNA SEL1L, which is highly similar to the C. elegans sel-1 gene, an important negative regulator of the "notch" pathway which acts as a key regulator of the cellular proliferation and specification processes in both vertebrates and invertebrates. The SEL1L gene maps to 14q24.3-31 and here we report its fine localization by HAPPY mapping, which determines its molecular distance to microsatellite markers isolated in the region. We have found two new polymorphic (CA)n microsatellites located in the gene, and have identified the exon-intron boundaries. The gene is composed of 21 exons spanning 70 kb of genomic DNA. Human SEL1L protein exhibits a high degree of similarity compared to the mouse and nematode homologs.

Amino Acid Sequence↗

Quantitative and qualitative evaluation of blood salvaged after extracorporeal circulation (ECC) in paediatric heart surgery. Study of biochemical, morphological and structural variations of RBC after ECC and after salvaging of ECC circuit priming blood.

The salvaging of ECC circuit priming blood is essential for reducing the morbidity related to homologous blood transfusions and the importance of this technique is inversely proportionate to the age and weight of the child. In infants, the washing and centrifugation of blood not only drastically reduce the risk of contracting blood-transmitted diseases and cut management costs, but are also of considerable hemodynamic importance, producing a rapid normalization of the patient's hematocrit and hemoglobin and balancing the O2 consumption/demand ratio. The marketing of miniaturized salvagin devices with 55 ml bowls by Dideco has made possible the recovery of small quantities of blood, so as to normalise the hematic crisis and permit the application of total hemodilution in low-weight patients. The salvaged blood shows an average hematocrit of 52.7+/-9.7% (max 68.1%) and an average hemoglobin of 17.6 +/- 2.9 g/dl (max 20.7 g/dl), and maintains its structural components, osmotic resistance, concentration of intraerythrocytic hemoglobin and mean corpuscular hemoglobin all intact. Washing with isoosmotic and isoionic hydroelectrolytic solutions normalizes the ionic situation in the post-operative period and activated blood salvaging after Extracorporeal Circulation. The use of solutions without nutritional substances results however in a considerable fall in the number of enzymes in the intraerythrocytic metabolic glucide chain (G6PDH: -40.7 +/- 14.3% p<0.001), (PK: -23.8 +/- 20.5% p<0.03). This drop may be responsible for erythrocytic morphological alterations (echinocytic change) and probably for the release of hemoglobin from the red blood cells. Washing with isoionic, isoosmotic solutions containing G5% and adenine could, at least in theory, improve the quality of the salvaged blood, by normalizing the morphology and the volume of the RBC and by increasing the hematocrit.

Adolescent↗

Bidirectional cavo-pulmonary anastomosis with an additional flow source to the lungs: clinical experience in 21 cases.

The Fontan operation is considered a palliative procedure for the treatment of complex congenital heart diseases with a morbidity and mortality that are not negligible, especially in high-risk patients. In these cases, a bidirectional cavopulmonary anastomosis with additional source of blood flow to the lungs can represent a valuable surgical option. Between November 1992 and December 1995, 21 patients with univentricular heart physiology were submitted to bidirectional cavopulmonary anastomosis with additional blood flow the additional flow consisted of an aortopulmonary shunt in 13 cases, pulmonary artery banding in seven cases, and pulmonary artery stenosis in one case. Mean age at operation was 35.5 months (range 4 months to 12 years) and mean body weight 10.9 (range 4-24.4) kg. Hospital mortality was zero. Morbidity (pleuropericardial effusions) was significant in one case. There were three late deaths (14%) caused by worsening atrioventricular valve regurgitation: two of these occurred in patients with right isomerism. Late haemodynamic evaluation documented a significant increase in cardiac output (P < 0.01) and oxygen saturation (P < 0.05) during pharmacological stress testing. Angiographic characterization of blood flow distribution to the lungs showed better results when the additional blood flow was represented by an anterograde source (pulmonary artery banding or native pulmonary artery stenosis). In conclusion, bidrectional cavopulmonary anastomosis with additional blood flow is a good alternative to classic or fenestrated Fontan technique in high-risk patients. Secondly, the diagnosis of isomerism could be a contraindication to this type of surgery, because the persistent volume overload could worsen atrioventricular valve regurgitation. Thirdly, the pharmacological stress testing shows a favourable behaviour of cardiac output and arterial oxygen saturation. Fourth, the type of additional blood flow seems to condition both pulsatility and distribution of pulmonary blood flow.

Child↗

[Differential types of pulmonary flow in bidirectional cavo-pulmonary anastomosis with an additional flow source].

While Fontan operation is considered a palliative procedure for the treatment of complex congenital heart disease, its morbidity and mortality are certainly not negligible, especially in high-risk patients. In our opinion, a bidirectional cavo-pulmonary anastomosis with an additional source of blood flow to the lungs (Blalock-Taussig shunt, pulmonary artery banding, native pulmonary stenosis) represents a valuable surgical option in this subset of patients. From November 1992 to September 1994, sixteen patients with complex congenital heart disease underwent bidirectional cavo-pulmonary anastomosis, leaving an additional source of blood flow in place (modified Blalock-Taussig shunt in 9 cases, pulmonary artery banding in 6 cases, native pulmonary stenosis in 1 case). Eight of these patients (50%) were reinvestigated after a mean follow-up of 15.7 months (range 1-26 m). It has been possible to differentiate two types of pulmonary blood flow, according to the nature of the additional flow source; in the case of cavo-pulmonary anastomosis and pulmonary artery banding or pulmonary stenosis, pulmonary blood flow was pulsatile and evenly distributed to both lungs, while in the case of bidirectional cavo-pulmonary anastomosis and Blalock-Taussig shunt, pulmonary flow was non pulsatile and asymmetric (angiographic criteria). There were no hospital deaths. Late mortality was 12.5% (2 pts) due to worsening of atrioventricular valve regurgitation. In one of these two patients, prolonged pleural and pericardial effusion occurred. In conclusion, bidirectional cavo-pulmonary anastomosis with an additional flow source is a good alternative to classic or fenestrated Fontan operation in the treatment of complex congenital heart disease. The best results are obtained with an additional flow source represented by pulmonary artery banding or pulmonary stenosis, due to pulsatility and uniform distribution of blood flow in the pulmonary district. Morbility and mortality compare favorably with the rates observed in classic or fenestrated Fontan operation.

Anastomosis, Surgical↗

[Classification of congenital heart diseases and surgical interventions in pediatric cardiology for the standardization of hospitalization records].

The utilization of DRGs for the evaluation of hospital activity requires the availability, on a current basis, of coded in-patient records (Hospital Discharge Form, SDO) with information concerning nosology of the patient and procedures performed. Consequently, the promotion of a standardized use of ICD.9 and ICD.9.CM code systems (International Classification of Diseases, 9th Revision, and International Classification of Diseases, 9th Revision, Clinical Modification) among clinicians is necessary. The National Research Council, Council Research Hospital for Cardiology and Cardiac Surgery (CREAS-IFC-CNR) has promoted the establishment of a permanent work group for the evaluation of the activity in the field of pediatric cardiology and cardiosurgery at a national level. In co-operation with two leading institution (AO "Bambino Gesù", Rome; AO "G. Gaslini", Genoa) an in-patient survey has been promoted including an overall revision of the ICD.9.CM code systems both for diagnosis and procedures in order to improve the standardization of data. Besides, the fitness of DRGs allocation by different codes has been judged. Some general and specific suggestions upon codes adequacy and DRGs identification have emerged from this study. The aim of this paper is to spread this preliminary standardization activity of the group as a contribution to the improvement of in-patient coded records quality.

Age Factors↗

[Closure of patent ductus arteriosus in thoracoscopy: analysis of the experience in the Gaslini Institute of Genoa].

In 1993, Laborde et al described a new surgical approach for closure of the patent ductus arteriosus (PDA), using a videoassisted technique. For the first time, videosurgery was utilized in pediatric cardiovascular surgery. The advantages of this new method are that it is minimally invasive (thoracotomy is replaced by three small holes), it reduces postoperative pain, recovery is more rapid with a shorter hospital stay and convalescence, and last but not least, it offers better aesthetic results. Between July 1994 and June 1996, we utilized the videoassisted thoracoscopic technique described by Laborde in 23 patients with PDA (age: 8 m-12 yrs, mean 45.2 m +/- 37.8; weight: 5.3-32 kg, mean 23 kg +/- 10.3). In two patients, we converted the procedure to standard thoracotomy due to anatomic problems. Echo-doppler evaluation, performed in the operating room shortly after the procedure, confirmed the complete closure of the PDA in all patients. There was neither morbidity nor mortality. The average hospital stay was four days. At a mean follow-up interval of 7.2 months (range 1-13 months), all patients showed excellent cosmetic results. We conclude that thoracoscopic closure of PDA is a valuable therapeutic option that can be used as an alternative to open-chest surgery and interventional cardiology.

Adolescent↗

Surgical management of complete atrioventricular canal associated with tetralogy of Fallot.

Between 1984 and 1993, 12 children with an atrioventricular canal and tetralogy of Fallot underwent surgical repair. The mean(s.d.) age at operation was 58(18) months, and the mean(s.d.) body weight 15(4) kg. Nine patients underwent 11 palliative procedures. The ventricular septal defect was closed through a combined (right atrial and right ventricular) approach in nine cases, and through a right atrial approach in three, using a prosthetic patch with a wide anterior extension, secured with a running suture. The 'ostium primum' defect was closed with a separate prosthetic patch in 11 cases (double-patch technique). Right ventricular outflow obstruction was relieved by a composite infundibular patch (seven cases) or a transanular patch (five). There were four hospital deaths (33%). These were caused by low cardiac output in three cases and infection in one (three deaths occurred in patients with a transanular patch). One patient has so far died during follow-up. Assessment at 50(36) months by echo-Doppler showed moderate-to-severe 'mitral' regurgitation in three cases, and moderate 'tricuspid' regurgitation with right ventricular dysfunction in one case. Two patients have required further surgery.

Blood Vessel Prosthesis↗

A postgraduate teaching course in laparoscopic surgery.

A teaching course in laparoscopic surgery was addressed to 21 young postgraduates as a part of their general surgery program with the aim of making them familiar with the basic principles of laparoscopic surgery. The methodology was based on tutorial teaching and "learning by problems"; the students worked in little groups elaborating check lists, discussing problems, and practising with laparoscopic training devices. Theoretical learning, practical abilities, and efficacy of tutorial teaching were investigated at the end of the course: the participant's understanding of instrument function, mastering of equipment, and solutions to clinical problems were good, as were the efficiency and pleasantness of the didactic method. Tutorial teaching seems to be a valid model for basic training in laparoscopic surgery in a modern medical education program.

Education, Medical, Continuing↗

Left ventricular morphology and diastolic function in uraemia: echocardiographic evidence of a specific cardiomyopathy.

OBJECTIVE: To see whether cardiac morphological and functional abnormalities in uraemic patients are determined by high blood pressure or if they are an expression of a specific cardiomyopathy. DESIGN: Cross sectional study. SETTING: City general hospital in Italy. SUBJECTS: 35 uraemic patients receiving haemodialysis (17 men, 18 women; mean age 60.3 (11.2); mean duration of dialysis 52 months) were selected from the 64 patients in Venice who were receiving dialysis; subjects with diabetes, haemochromatosis, valvar dysfunction, regional dyskinesias, and pericarditis were excluded. 19 control normotensive subjects (6 men and 13 women), matched for age. MAIN OUTCOME MEASURES: Echocardiographic measurements of left atrium, left ventricular end diastolic and end systolic volume, aortic root diameter, posterior wall and interventricular septum thickness, left ventricle mass index, and ejection fraction in controls and in patients according to whether they were normotensive (five men, eight women) or hypertensive (12 men, 10 women) on 48 hour ambulatory monitoring; left ventricular diastolic function by Doppler ultrasonography. RESULTS: Mean systolic and diastolic pressures, daytime systolic and diastolic pressures, and night time systolic and diastolic pressures were significantly higher in the hypertensive patients than in the normotensive patients. The normotensive patients had similar blood pressures to the controls. Left ventricular mass correlated significantly with the mean diastolic pressure and mean night time systolic and diastolic pressures. Parathyroid hormone concentrations were similar in the two groups of patients. Diastolic relaxation was impaired to the same degree in the two groups of patients. Parameters of diastolic function showed no relation to left ventricular mass, which was significantly higher in the hypertensive than in the normotensive patients. CONCLUSIONS: Uraemia is likely to induce specific changes in the relaxation properties of the myocardium. These changes are responsible for the impaired diastolic function independently of blood pressure, degree of hypertrophy, and metabolic changes, which suggests the existence of a specific cardiomyopathy. Hypertension remains a determinant of left ventricular mass.

Diastole↗

Interrupted aortic arch and aortopulmonary window: one-stage repair in the first week of life.

Aortic arch interruption associated with an aortopulmonary window is a rare congenital malformation that needs an early diagnosis and surgical treatment to avoid irreversible pulmonary lesions. Here we describe a case of a successful one-stage surgical repair in a 3-day-old neonate, without the use of prosthetic material, for the correction of the aortic arch interruption.

Aorta, Thoracic↗

Aortic coarctation with hypoplastic arch in neonates: a spectrum of anatomic lesions requiring different surgical options.

Hypoplasia of the transverse aortic arch is frequently associated with isthmic coarctation in many patients referred for operation in early infancy, and the surgical technique should be adjusted to suit each type of anatomic lesion. Referring to the anatomic description of hypoplastic aortic arch reported by Moulaert and associates, between January 1988 and July 1991 we operated on 32 consecutive infants (< or = 3 months old) using a surgical approach based on the echocardiographic and angiographic findings; 20 patients (62%) were younger than 2 weeks of age and 20 patients (62%) had associated intracardiac lesions. According to the location, extension, and size of the hypoplasia of the aortic arch, we had three groups of patients: in group 1 (21 patients) we performed resection and extended end-to-end anastomosis, as previously described in 1985; in group 2 (5 patients) we performed resection, posterior end-to-end anastomosis, and anterior subclavian flap enlargement; and in group 3 (6 patients) we performed direct side-to-end anastomosis between ascending and descending aorta through a median sternotomy. One patient died during the postoperative course in group 3. With a mean follow-up time of 26 months we had 4 cases (13%) of "residual" or "recurrent" coarctation in group 1, successfully repaired at 2 months of age by an anterior approach in 2 patients and by percutaneous angioplasty in the others. In conclusion, hypoplastic aortic arch in neonates represents a common difficulty, and optimal reconstruction of the entire aortic arch is mandatory to reduce operative mortality and incidence of recoarctation, especially when there are complex associated intracardiac lesions or left ventricular dysfunction.

Aorta, Thoracic↗

Tubular supravalvar aortic stenosis: replacement of ascending aorta in a young patient.

The diffuse form of supravalvar aortic stenosis represents a surgical challenge when ascending aorta and proximal aortic arch are involved. We describe a technique performed on a 14-year-old patient with normal aortic annulus and severe diffuse supravalvar aortic stenosis in which the replacement of ascending aorta and proximal aortic arch with a tubular prosthetic graft completely relieved the obstruction as confirmed by cardiac catheterization.

Adolescent↗