PubMed Health⌕ Search

Biomedical subjects

F Simeone

Publications and source records attributed to F Simeone.

At least 19 recordsLinked to original sources
PubMed2002

Cardiac surgery: myocardial energy balance, antioxidant status and endothelial function after ischemia-reperfusion.

Myocardial and endothelial damage is still a widely debated problem during the ischemia-reperfusion sequence in heart surgery. We evaluated myocardial purine metabolites, antioxidant defense mechanisms, oxidative status and endothelial dysfunction markers in 14 patients undergoing coronary artery by-pass graft (CABG). Heart biopsies were taken before aortic cross-clamping (t1), before clamp removal (t2) and 30 min after reperfusion (t3); perchloric extracts of the tissue were analyzed for glutathione, NAD, nucleotide nucleoside and base content by capillary electrophoresis (CE). In plasma samples from the coronary sinus we evaluated: nitrate and nitrite concentrations by CE, plasma glutathione peroxidase (plGPx) by ELISA, endothelin-1 (ET-1) by RIA and reactive oxygen metabolites (ROM) by colorimetric assay. During the ischemic period (t2) we observed a reduction in cellular NAD and GSH levels, as well as nitrate, nitrite and plGPx. ATP and GTP levels decreased and their catabolic products AMP, GMP, IMP, adenosine, inosine and hypoxanthine accumulated. The energy charge, ATP/ADP ratio, and nucleotide/(nucleoside + base) ratios decreased. At t3, levels of plasma ET-1 increased and monophosphate nucleotides tended to return to basal values. The energy charge did not increase but the nucleotide/(nucleoside + nucleobase) ratio recovered to some extent. Levels of nitrates plus nitrites continued to decrease. No significant variation in ROM levels was observed. Our data indicate that oxidative stress and endothelial damage are major events during CABG, overwhelming the scavenging capacity of the myocyte and preventing restoration of the normal energy balance for 30 min after reperfusion. The AMP deaminase pathway leading to IMP production is active during ischemia and adenosine is not the main compound derived from ATP break-down in the human heart. The possible role of extracorporeal circulation is also discussed.

Aged↗
PubMed2002

Optimization of mechanical ventilation support following cardiac surgery.

BACKGROUND: Mechanical ventilation (MV) is essential in the management of patients that underwent cardiac surgery and cardiopulmonary bypass. It has been demonstrated that MV dependence is directly related to morbidity incidence and ICU length of stay, with a strong impact on economic cost. Therefore identification of measures that can reduce MV interval, may reduce the incidence of respiratory complications and length of hospitalization. The aim of this study was to identify weaning indexes and adopt a weaning algorithm in order to optimize ventilatory support after cardiac surgery. METHODS: Forty-nine patients with low and medium Higgins risk score, who underwent, between February and November 1999, elective surgery at our Institution, were enrolled in this study. All patients were randomized into 2 groups: Group I (weaning group - 24 patients), extubated with the aid of a weaning protocol, and Group II (control group - 25 patients), extubated with conservative weaning, dependent on the physician's subjective clinical judgment. All patients were successfully weaned from mechanical support. RESULTS: Intubation time was significantly lower in Group I than Group II and "Fast Track Recovery" group (p=0.05). ICU length of stay was also significantly lower in Group I (p=0.03). Analysis of weaning indexes did not show cut-off points predictive of successful weaning, except for PaO2/FiO2 ratio, which was higher in Group I (p=0.02). CONCLUSIONS: These results confirm that the use of a weaning algorithm enables the MV interval and hospital length of stay to be shortened, suggesting that it should be used in the management following cardiac surgery.

Aged↗
PubMed2001

Image-guided transorbital roof craniotomy via a suprabrow approach: a surgical series of 72 patients.

OBJECTIVE: Many subfrontal and orbitofrontal craniotomy techniques have been developed. We present our results with the transorbital roof craniotomy, a frontal craniotomy that incorporates the orbital roof and is performed via a suprabrow incision. This technique was used in 72 patients, primarily for tumor resection. METHODS: Charts were retrospectively reviewed for all patients undergoing transorbital procedures. A total of 72 patients underwent 82 transorbital craniotomies from September 1995 to July 1999. The primary indication for the transorbital approach was mass lesion of the orbit, anterior fossa, or parasellar region. RESULTS: A total of 47 women and 25 men with a mean age of 53 years underwent 82 procedures. The primary pathological finding was meningioma, which occurred in 40 patients (55.6%), followed by craniopharyngioma (6.9%), pituitary macroadenoma (6.9%), schwannoma (5.5%), and hemangioma (5.5%). Simpson Grade I or II resection was achieved in 54% of patients, with Simpson Grade III to V resection achieved in the remaining 46%. Forty-one patients presented with visual loss in 43 cases, with 44.2% experiencing postoperative visual improvement, 46.5% remaining unchanged, and 9.3% worsening. Overall morbidity was 18.4%, with cerebrospinal fluid leak being the most common complication (6.6%). No patients died. CONCLUSION: The transorbital roof craniotomy is an evolutionary approach that provides excellent exposure to the orbit, anterior fossa, and parasellar region with little significant morbidity and, in our series, no mortality. Although we have used this approach primarily for resection of mass lesions, future directions for this procedure will likely lie in treating vascular lesions and lesions of the interpeduncular fossa.

Adult↗
PubMed1999

The diagnostic and prognostic value of cardiac Troponin T in bypass surgery.

BACKGROUND: The purpose of this study was to verify the utility of serum Troponin T (TnT) in the diagnosis of myocardial damage after coronary surgery performed using different methods of myocardial protection. The prognostic value of TnT peak for a poor postoperative course was also investigated. METHODS: Forty-three patients were enrolled and randomised in 2 group: Group A (n. 22) receiving warm blood cardioplegia and Group B (n. 21) receiving cold blood cardioplegia. According to TnT peak levels 3 subgroups were identified: Subgroup 1 (TnT peak < than 1 ng/ml); Subgroup 2 (TnT peak between 1 and 3 ng/ml), Subgroup 3 (TnT peak >3 ng/ml). A comparison with the standard criteria for diagnosis of myocardial ischemia was performed for each subgroup of patients. A 12 months follow-up for the patients of subgroups 1 and 2 was also completed in order to evaluate the prognostic value of a higher TnT peak. RESULTS: The overall patients subdivision in subgroup 1, 2 and 3 was 20 (46.5%), 14 (32.5%) and 9 (20.9%) respectively with no statistical difference for Group A or B. Only 7 of the patients of subgroup 3 (87%) matched the WHO diagnostic criteria for myocardial infarction. At the overall follow-up, 2 (14.28%) patients of subgroup 2, and 4 (20.0%) of subgroup 3, revealed a residual ischemia at the ECG-stress test even if none of these needed reoperation. CONCLUSIONS: Our data confirmed the high sensitivity and specificity of TnT measurement in the diagnosis of myocardial infarction and minor myocardial damage. This study, however, failed to show any statistically significant difference of the TnT peak when using different strategies of myocardial protection. The late prognostic value of the TnT increase in the early post-operative course has to be confirmed from a further study.

Aged↗
PubMed1998

Myocardial ischemic injury and purine metabolism in patients undergoing coronary artery bypass.

OBJECTIVES: High-energy phosphates and their catabolic products were determined in myocardium during coronary artery bypass surgery with blood cardioplegic reperfusion in order to evaluate the effects of aortic cross-clamping and reoxygenation on myocardial purine metabolism. DESIGN AND METHODS: Transmural left ventricular biopsy specimens were taken with ITu-Cut biopsy needles, before aortic cross-clamping, before cross-clamp removal and after 30' of reperfusion; perchloric extracts of the material were analyzed for nucleotide content by capillary zone electrophoresis (CZE). The CZE procedure used separates the complete spectrum of purine metabolites in myocardial extracts obtained from 0.6-8.6 mg biopsy material. RESULTS: The basal values of ATP/ADP ratio and energy charge were low, IMP content was high. After the ischemic period, ATP levels further decreased and IMP, nucleosides and bases accumulated. After reperfusion, nucleoside and base basal levels, but not energy charge, were restored to some extent. CONCLUSIONS: The study arises the problem of myocardial preservation during heart surgery. In this investigation, capillary electrophoresis was an extremely adaptable technique for the evaluation of ischemic injury and could be useful in studying the effects of cardioplegic solutions.

Aged↗
PubMed1998

Well-differentiated papillary adenocarcinoma arising in a supratentorial enterogenous cyst: case report.

OBJECTIVE AND IMPORTANCE: We report a case of a well-differentiated papillary adenocarcinoma arising in an supratentorial enterogenous cyst. The clinicopathological features of this case and a brief review of the literature are presented. CLINICAL PRESENTATION: A 45-year-old woman presented with abrupt onset of sensory seizures and abnormal sensation on the left side of her face, left leg, and left arm. Radiological studies showed a cystic extraaxial tumor with mass effect in the right parietal area. The initial clinical impression was a metastatic lesion, and a comprehensive metastatic workup revealed no evidence of tumor elsewhere. INTERVENTION: A gross total resection of the solid cystic tumor was achieved by a frontoparietal craniotomy. Sixteen months after the initial surgery, the patient presented with signs of increased intracranial pressure and a large parietal cyst. The cyst was fenestrated at the time of the second craniotomy. CONCLUSION: A pathological study of the initial surgical material revealed it to be a well-differentiated papillary adenocarcinoma in association with an enterogenous cyst. The second surgical specimen consisted only of the benign cyst wall. The patient recovered uneventfully from the second surgery and was free of symptoms 6 months postoperatively. The importance of recognizing the rare possibility of malignant progression of a benign enterogenous cyst in the central nervous system is discussed.

Adenocarcinoma, Papillary↗
PubMed1996

Perioperative use of botulinum toxin for movement disorder-induced cervical spine disease.

Patients with cervical dystonia or tics of the nuchal muscles can develop serious cervical spine disease. We report a series of four patients who received botulinum toxin injections to control their movement disorders prior to their required surgery. One patient with cervical tic-induced radiculomyelopathy required botulinum toxin injection postoperatively to facilitate stabilization of the cervical fusion. Two patients with torticollis-induced cervical radiculomyelopathy, and one patient with dystonia-induced C5 fracture, had botulinum toxin injected preoperatively to facilitate postoperative recovery. Botulinum toxin appears to be a useful adjunct in the treatment of cervical movement disorders prior to or following surgery for associated cervical spine disease.

Adult↗
PubMed1994

Assisted circulation in postcardiotomy heart failure: experience with the Bio-Medicus centrifugal pump in ten patients.

Between January 1990 and September 1992, ten patients required assisted circulation for postcardiotomy heart failure which was unresponsive to inotropic drugs and aortic counterpulsation. All patients were supported by a Bio-Medicus centrifugal pump (biventricular assist in five, left ventricular in three, right ventricular in two); six had ischaemic heart disease, two a congenital ventricular septal defect, one an acute mitral valve incompetence and one an aortic type 'A' dissection. The mean duration of circulatory support was 5.1 days (range 2 hours to 8 days). Six patients were weaned from the device and four were discharged; the perioperative deaths among the patients weaned from support were the result of cerebral haemorrhage and multiorgan failure respectively. No late deaths occurred at a mean follow-up of 15 months. Common complications were bleeding (40%), acute renal failure (30%) and sepsis (30%). All patients who developed renal failure died. The high incidence of haemorrhagic complications makes the use of pre-heparinized circuits desirable as these patients do not then require additional anticoagulation.

Acute Kidney Injury↗
PubMed1994

[Dosimetric and qualitative evaluations of the use of rhodium filtration in mammography].

The value of rhodium filtration in mammography was compared with that of conventional molybdenum; dosimetric and qualitative tests were performed on a phantom and in vivo on informed and consenting patients. Phantom dosimetric tests confirmed a dose reduction with rhodium filtration changing according to thickness and primary beam energy. With rhodium filtration the dose decreased by 40% on the average topping 67% in breasts thicker than 6.5 cm. No significant differences were observed between rhodium and molybdenum filtration in clinical and phantom qualitative tests. Four radiologists--three of them in double blind--studied 29 mammograms repeated in the same technical setting and expressed a very slight preference for molybdenum also in thick and dense breasts. The slight preference was not based on higher diagnostic yield and therefore clinically irrelevant. Preferences appeared to be subjective, differing from one radiologist to another. In conclusion, the authors suggest the use of rhodium filtration in thick breasts because of the lower administered dose and of shorter exposure time with direct magnification.

Breast Neoplasms↗
PubMed1994

Measurement of cardiac troponin T and myosin to detect perioperative myocardial damage during coronary surgery.

This study evaluated the use of monitoring blood levels of the isoenzyme of creatine phosphokinase, troponin T (tnT) and myosin in the detection of perioperative myocardial damage after coronary artery surgery. Serial blood samples were collected in 24 patients undergoing myocardial revascularization. The patients were retrospectively divided into three groups: group A with no changes in their electrocardiogram; group B showing non-specific signs of perioperative myocardial infarction such as deep and permanent T wave inversion; and group C with definite electrocardiographic signs of perioperative myocardial infarction (new persistent Q-waves and loss of R-waves). Group A (n = 17) demonstrated a mean(s.d.) troponin T peak blood level of 0.64(0.35) ng/ml at 12-24 h after surgery, a myosin peak of 1030(670) mu units/l at 3-6 days afterwards, and a creatine phosphokinase isoenzyme peak of 25.8(10.6) units/l. In group B (n = 5), mean(s.d.) troponin T levels were elevated to a peak of 4.8(3.9) ng/ml 24 h after intervention, while myosin rose to 2074(340) mu units/l 3-6 days after surgery and creatine phosphokinase isoenzyme reached 57.8(38) units/l. Group C (n = 2) had a mean(s.d.) troponin T peak of 4.8(2.6) ng/ml, a myosin peak of 2404(392) mu unit/l and a creatine phosphokinase isoenzyme peak of 88.5(20) units/l. Peak values of troponin T and myosin in groups B and C were statistically different from those in group A (P < 0.001). These results suggest that troponin T and myosin are reliable indicators of perioperative myocardial damage. In particular, troponin T may allow the differentiation of reversible from irreversible myocardial injury.

Biomarkers↗
PubMed1993

Myocardial function in early hours after coronary artery bypass grafting: comparison of two cardioplegic methods.

The theoretical advantages of retrograde blood cardioplegia combined with anterograde blood cardioplegia and warm reperfusion before aortic unclamping during coronary surgery were evaluated in 41 patients (group 2). The early postoperative myocardial function of this group was compared with that of 55 patients (group 1) in whom cold crystalloid cardioplegia was administered. The following variables were measured and analyzed by multivariate statistical analysis: heart rate, left atrial pressure, systemic arterial pressure, cardiac index, left ventricular stroke work index, ventricular function, oxygen delivery, hemoglobin, partial oxygen pressure in mixed venous blood, arteriovenous oxygen difference, carbon dioxide production per square meter, and cardiac isoenzyme of creatine-kinase. The myocardial function improved progressively and cardiac enzymatic release was low for both groups 9 hours after admission to the intensive care unit. However, group 2 had significantly higher oxygen delivery, carbon dioxide production per square meter, cardiac index, left ventricular stroke work index, and ventricular function and significantly lower left atrial pressure and mean systemic arterial pressure than that of group 1. The best separation of group 2 from group 1 occurred at the ninth hour, with a probability of correct recognition of 92.1%.

Blood Pressure↗