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Biomedical subjects

F Miraldi

Publications and source records attributed to F Miraldi.

At least 19 recordsLinked to original sources
PubMed2002

Preservation of myocardial energy status by bovine hemoglobin solutions during ischemia.

Compared to murine and human hemoglobin, bovine hemoglobin has a less exothermic oxygen binding and delivers oxygen even at low temperatures. This property could improve oxygen availability for myocytes during hypothermic arrest of hearts. The aim of this study was to evaluate the advantage of using cardioplegic solutions enriched with bovine hemoglobin when storing rat hearts. Hearts excised from rats after perfusion with different cardioplegic solutions (Celsior, Celsior plus 4% human hemoglobin, Celsior plus 4% and 8% bovine hemoglobin) were compared. Biopsies were obtained from the beating hearts before cardioplegic infusion and during a 48 h period of cold storage. Adenosine triphosphate, its catabolites and markers of oxidative stress were measured as indices of preservation. The results show that bovine hemoglobin-enriched solutions highly improve adenosine triphosphate content, decreasing its catabolites; no significant changes in antioxidant status were evident. The statistically significant difference was evident up to 6 h of storage. Doubling the concentration of bovine hemoglobin produces only slight improvement. Alternative hemoglobins with different properties may improve and prolong heart storage. As bovine hemoglobin delivers oxygen even at low temperatures, it improves energy content and anabolic reactions, without decreasing oxidative stress.

Animals↗
PubMed2002

Antiphospholipid antibodies and intracardiac thrombosis. A case report.

The antiphospholipid syndrome (APS) has been associated with multiple cardiac abnormalities. The present report describes a case of right ventricle thrombus in a 51-year-old woman with a history of autoimmune haemolytic anemia and antiphospholipid antibodies. Transthoracic echocardiography demonstrated the presence of a right ventricle mass, mimicking a myxoma. She underwent open heart removal of the mass and was started on indefinitely anticoagulant therapy. At 2 years follow-up she was free of symptoms.

Anemia, Hemolytic, Autoimmune↗
PubMed2001

Positive emission tomography for evaluating a complete clinical response in patients with ovarian or peritoneal carcinoma: correlation with second-look laparotomy.

OBJECTIVE: Positive emission tomography (PET) provides a novel means of imaging malignancies. The following study was undertaken to evaluate the predictive value of PET in determining a pathologic complete response in patients with advanced ovarian or peritoneal carcinoma who had a complete clinical response following primary chemotherapy. METHODS: Twenty-two patients with advanced-stage ovarian (N = 17) or peritoneal (N = 5) carcinoma who had achieved complete clinical and radiologic remission and normal CA-125 level after six cycles of chemotherapy and who had consented to a second look laparotomy procedure were studied. All patients received platinum based therapy and all but one patient, treated elsewhere, received paclitaxel in combination with platinum. Following IV administration of 20 mCi [(18)F]fluorodeoxyglucose (FDG), the entire abdomen and pelvis were scanned. Various technical modifications including bladder activity dilution, intravenous hydration with diuretic therapy, and mechanical bowel preparations, were used to reduce background activity. Second-look laparotomy findings were classified as negative, macroscopically positive if a biopsy of a suspicious area was histologically positive, or microscopically positive if only a nonsuspicious area was histologically positive. The effect of patient preparation prior to PET imaging was evaluated. RESULTS: Persistent disease was found in 13 of the 22 patients (59%). Only one of nine sites with macroscopic and none of four with microscopic disease were accurately predicted. The sensitivity was only 10% and the specificity 42%. Intravenous hydration, diuretic therapy, and bowel preparation did not improve the results. CONCLUSIONS: These results suggest that despite technical modifications the sensitivity of PET before second-look laparotomy for small-volume persistent disease is low.

Adenocarcinoma, Mucinous↗
PubMed2001

Emergency surgery for retrograde extension of type B dissection after endovascular stent graft repair.

Endovascular stent graft repair of type B dissection is a new and alternative treatment to the surgical or medical therapy. This technique is not free from minor or major complications and we herein report the case of a patient who developed a retrograde dissection after endovascular stent graft placement. The emergent surgical treatment undertaken consisted of ascending aorta replacement without treating the arch in account of the presence of the endoluminal prosthesis.

Aortic Dissection↗
PubMed2001

Increased expression of thyroid hormone receptor isoforms in end-stage human congestive heart failure.

Thyroid hormone plays an important role on myocardial development and function. The local effects of thyroid hormone are mediated by the receptor isoforms ultimately driving the expression of cardiac-specific genes. Although overt and subclinical thyroid dysfunction causes well-known changes in the cardiovascular system, little is known about local thyroid hormone action in normal and failing human myocardium. With a newly developed multiplex competitive RT-PCR method, we evaluated the expression of thyroid hormone receptor (TR) isoforms alpha-1, alpha-2, and beta-1 in normal human hearts and in end-stage congestive heart failure. A statistically significant difference in the expression of all three TR isoforms was observed among samples from normal subjects, ischemic heart disease (IHD), and dilated cardiomyopathy (DCM). In DCM, compared with normal, the studied TR isoforms were significantly increased. In IHD, the increased expression was found significant only for alpha-1 and alpha-2 isoforms. No differences were observed between the pathologic groups. In conclusion, a coordinated increment in the expression of the TR isoforms was observed in both DCM and IHD by multiplex competitive RT-PCR. The observed changes could represent a compensatory mechanism to myocardial failure or to locally altered thyroid hormone action.

Adult↗
PubMed2001

Chylothorax: a complication after internal thoracic artery harvesting.

Chylothorax is a rare but serious complication of cardiac surgery. A 64-year-old man with three-vessel disease underwent coronary artery bypass grafting. Ten days later he developed left pleural effusion. An intercostal drain was inserted and 1600 ml of pale pink, milky fluid were obtained. The results of biochemical analysis were consistent with chyle. The diagnosis of a left chylothorax was made. Conservative treatment consisting of total parenteral nutrition and pleural drainage was successfully employed. In the literature we found 17 cases in which the development of chylothorax after a coronary revascularization procedure is described.

Chylothorax↗
PubMed2001

Hormone metabolism in the pulmonary circulation.

We measured hormonal levels in blood samples from pulmonary and radial arteries in 117 patients undergoing aorto-coronary by-pass surgery with the aim of investigating the role of the pulmonary vessel endothelium in hormone metabolism. Insulin and glucagon concentrations were significantly higher in pulmonary artery blood with respect to radial artery blood (73 +/- 65 vs. 65 +/- 47 pmol/l, p < 0.005, and 80 +/- 49 vs. 73 +/- 51 ng/l, p < 0.01, respectively), while no difference was found for growth hormone, prolactin, C peptide, insulin-like growth factor I, follicle stimulating hormone, luteinizing hormone, thyroid stimulating hormone, parathyroid hormone, thyroglobulin, triiodothyronine, thyroxine, free triiodothyronine, and free thyroxine. Moreover, prolactin concentrations were more than twice the normal levels, this being an effect of propafol and the opiate fentanyl used for the general anesthesia. Assuming that the arteriovenous differences observed are a marker of peptide hormone degradation, our study has demonstrated that with similar kinetics insulin and glucagon secreted into portal circulation and escaping from hepatic extraction undergo further homeostatic removal of about 9-10 % in the pulmonary circulation before entering the general circulation.

Aged↗
PubMed2000

A circuit to perform a combined ultrafiltration procedure in pediatric open heart surgery.

Cardiopulmonary bypass (CPB) induces an increased capillary permeability and tissues water content due to hemodilution and the inflammatory response, resulting in organ dysfunction. The reduction of the water accumulation and inflammatory response can be achieved by employing ultrafiltration during CPB. Recently we developed a simple CPB circuit for ultrafiltration using the aortic venting tube as an inlet line. Such a technique offers the advantages of performing a combined ultrafiltration procedure and eliminating the danger of air embolism. We employed this circuit in 12 consecutive pediatric patients undergoing open heart surgery.

Cardiopulmonary Bypass↗
PubMed2000

Undergoing cardiopulmonary bypass using enoxaparin only during a cardiac transplantation procedure.

The use of enoxaparin as a replacement drug to standard heparin, for anticoagulation during extracorporeal circulation, in patients with heparin-induced thrombocytopenia, is still very limited. Enoxaparin significantly reduces thrombin formation and activity during cardiopulmonary bypass. The prolonged circulating rate, slow elimination rate and non-total reversion of enoxaparin by protamine can induce important postoperative bleeding. We are describing the first case of cardiac transplantation where enoxaparin was used as a replacement drug to standard heparin.

Adult↗
PubMed1999

Positron emission tomography for evaluating para-aortic nodal metastasis in locally advanced cervical cancer before surgical staging: a surgicopathologic study.

PURPOSE: Positron emission tomographic (PET) scanning provides a novel means of imaging malignancies. This prospective study was undertaken to evaluate PET scanning in detecting para-aortic nodal metastasis in patients with locally advanced cervical carcinoma and no evidence of extrapelvic disease before planned surgical staging lymphadenectomy. MATERIALS AND METHODS: After 20 mCi of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) were administered intravenously, the abdomen and pelvis were scanned. Continuous bladder irrigation was used to reduce artifact. Patients were classified by the presence or absence of FDG uptake in the primary tumor and in pelvic or para-aortic nodes. Para-aortic node metastases were classified as present or absent according to a standardized staging procedure. Pelvic node metastases were similarly classified in a subset of patients who underwent pelvic node resection. RESULTS: Thirty-two patients with stage IIB (n = 6), IIIB (n = 24), and IVA (n = 2) tumors were studied. Fluorodeoxyglucose was taken up by 91% of the cervical tumors. Six of eight patients with positive para-aortic node metastasis had PET scan evidence of para-aortic nodal metastasis. One of the two false-negatives had only one microscopic focus of metastatic cancer. In the para-aortic nodes, PET scanning had a sensitivity of 75%, a specificity of 92%, a positive predictive value of 75%, and a negative predictive value of 92%. Fluorodeoxyglucose para-aortic nodal uptake conferred a relative risk of 9.0 (95% confidence interval, 2.3 to 36.0) for para-aortic nodal metastasis. All 10 of 17 patients with metastasis were predicted by PET scanning (P < .001); five of these patients had abnormalities on computed tomographic scans. CONCLUSION: Cervical cancers have a high avidity for FDG. The use of PET-FDG scanning accurately predicts both the presence and absence of pelvic and para-aortic nodal metastatic disease.

Aorta↗
PubMed1999

Siena's experience with pulmonary autograft operations: clinical and echocardiographic follow-up.

As there is no perfect aortic valve substitute, there is a need to find out which one is the best option to replace the diseased aortic valve. Any type of mechanical or biological stented device has a residual gradient and does not reproduce the extremely sophisticated normal aortic valve function. This may influence the short- and long-term outcome, especially in dilated and poorly contracting left ventricles which do not tolerate even a mild stenosis. Thus, the potentially ideal valve to replace the aortic valve is either an aortic valve (aortic homograft) or a pulmonary autograft in aortic position. These grafts are also less subject to endocarditis. It has been demonstrated that pulmonary autografts can grow when implanted in children and as they remain viable, they maintain their dynamic behavior and possibly the internal innervation of the cusps. Unfortunately, pulmonary autograft surgery is more demanding and lasts longer, which may increase the risk of the operation. In addition, the exact indications and applications of the operation, particularly in patients with poor left ventricles or additional lesions, have not been clearly defined. Here we report our experience with this technique in 11 patients with severe aortic valve disease, including those with poor left ventricle function and/or associated disease. We describe our short- and medium-term follow-up, which shows optimal left ventricle recovery with no perioperative or postoperative complications, thus supporting a wider application of the operation.

Adult↗
PubMed1998

The role of fluorodeoxyglucose and positron emission tomography in the evaluation of pancreatic disease.

BACKGROUND: The difficulties involved in the timely and accurate diagnosis of pancreatic disease are well known. The usual imaging modalities usually identify abnormalities but may not always differentiate malignancy from other condition such as scar tissue or chronic inflammation. The purpose of our study was to determine if fluorodeoxyglucose positron emission tomography (FDG PET) can accurately diagnose pancreatic disease. METHODS: The records of 15 patients presenting with pancreatic disease were retrospectively reviewed. The diagnosis suspected by imaging modalities was compared with the final tissue diagnosis. Two patients were excluded because no tissue was obtained. RESULTS: Adenocarcinoma was diagnosed in 9 patients. A mass consistent with this diagnosis was seen in 8 of 9, 6 of 9, 6 of 8, and 5 of 5 patients by PET, computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS), respectively. Chronic pancreatitis (CP) was diagnosed in 2 patients. The unique appearance on FDG PET made the diagnosis in both these patients. Both patients with CP were thought to have a malignancy by CT and EUS and 1 of 2 by ERCP. Neuroendocrine tumors were diagnosed in 2 other patients. One of 2 was seen by FDG PET and both by CT. CONCLUSIONS: FDG PET can accurately differentiate a pancreatic adenocarcinoma from chronic pancreatitis in a patient with a suspicious pancreatic mass. Thus, FDG PET may help in establishing a diagnosis and subsequently managing a patient with pancreatic disease.

Adenocarcinoma↗
PubMed1998

Elimination of artifactual accumulation of FDG in PET imaging of colorectal cancer.

BACKGROUND: Positron emission tomography (PET) with fluorine-18 labeled deoxyglucose (FDG) can detect tumor recurrences in surgical patients that are otherwise difficult to assess by CT, as well as distant metastases and small malignant nodes that are not identified by other imaging modalities. However, the evaluation of such malignancy is complicated by urinary and colonic concentrations of FDG. Methods and examples of the elimination of artifactual accumulation of FDG in PET imaging of the abdomen and pelvis are presented. METHODS: Elimination of artifactual accumulation requires patient preparation that begins with cleansing of the colon using an isosmotic solution taken the evening prior to examination. Approximately 500 MBq of F-18 FDG is intravenously administered upon arrival at the PET facility and then the patient is hydrated. After administration of furosemide, a Foley catheter with a drainage bag is placed and the patient is then scanned. Just prior to scanning over the pelvis, normal saline is delivered retrogradely into the urinary bladder. At the end of scanning, the patient voids and repeated pelvic images are obtained. RESULTS: These routines yield a clean scanning field. Lesions that will generally be missed because they are obscured by FDG accumulations along the colon or in the kidneys, ureters, or bladder are better visualized and identified with greater confidence. Artifacts that lead to misinterpretation also are reduced. CONCLUSION: Elimination of artifactual accumulation of FDG in the colon and urinary system is essential if primary cancer, associated adenopathy, or subtle recurrences are to be evaluated in FDG PET imaging of the abdomen and pelvis.

Abdomen↗
PubMed1998

Biodistribution and kinetics of nasal carbon-11-triamcinolone acetonide.

UNLABELLED: PET is a technique with a strong potential for use in drug evaluation and development. In particular, the distribution and pharmacokinetics of locally administered drugs may be advantageously explored noninvasively using labeled compounds. This pilot study was performed to demonstrate the effectiveness of PET for drug development and to determine the human biodistribution and kinetics of triamcinolone acetonide, labeled with 11C, formulated and nasally administered as Nasacort AQ nasal inhalant. METHODS: Carbon-11-labeled triamcinolone acetonide was formulated as the commercial product, and PET scans of the heads of four volunteers were performed in a vertical orientation. Region-of-interest analysis with MRI coregistration was used to analyze the distribution and kinetics in nasal tissues. RESULTS: Deposition of the majority of the dose on target tissues was immediate. Penetration into sinuses was observed. There was moderate redistribution and slow migration of the drug through nasal passages to the throat. Significant amounts of the drug remained in target regions for several hours. CONCLUSION: PET is an effective means to determine local drug distribution and kinetics.

Administration, Inhalation↗
PubMed1997

Neuroimaging of vessel amyloid in Alzheimer's disease.

Despite extensive recent advances in understanding Alzheimer's disease (AD) we are unable to noninvasively establish a definite diagnosis during life and cannot monitor the cerebral deposition of amyloid beta protein (A beta) in living patients. We evaluated the use of 10H3, a monoclonal antibody Fab targeting A beta protein 1-28 labeled with Tc-99m. Six subjects with probable AD were studied using single-photon emission computed tomography (SPECT) at times from 0-24 hours following injection. Curves of radioactivity in blood demonstrate a half-life of the injected Fab of 2-3 hours. Images show uptake around the head in the scalp or bone marrow in all subjects. There is no evidence of cerebral uptake of the antibody. Scalp biopsies in all six patients demonstrate diffuse staining with 10H3 of the scalp, a pattern indistinguishable from that found in controls. Evidence of amyloid deposition in the scalp in AD is not seen with other anti-A beta antibodies, suggesting that 10H3 is cross-reacting with another protein. Further studies with anti-A beta antibodies will require longer-lived radionuclides to detect cerebral uptake at later times after injection to allow for complete clearance from the blood. Alternately, imaging using labeled A beta itself may provide a means for noninvasive targeting of cerebral amyloid.

Alzheimer Disease↗
PubMed1997

Technical improvements in fluorine-18-FDG PET imaging of the abdomen and pelvis.

UNLABELLED: PET tumor imaging of the abdomen and pelvis is prone to artifacts due to urinary tract activity. A new technique has been developed to reduce such artifacts and enhance study interpretation. METHODS: Thirty minutes after the injection of 18F-FDG, 500 cc 0.45% NaCl were administered intravenously over 30 min and a Foley catheter was placed in the bladder. At the start of imaging (60 min post-injection), furosemide was given (0.3 mg/kg). Prior to imaging the pelvis, the urinary catheter was clamped and saline was introduced retrograde into the bladder until full. RESULTS: This technique has been used successfully in more than 130 patients, resulting in a marked improvement in study quality and tumor detection. CONCLUSION: Hydration and administration of furosemide, along with placement of a Foley catheter in the bladder, have proven effective in eliminating image artifacts originating from the kidneys, ureters and bladder. Backfilling the bladder also provides a well-defined anatomic landmark for study interpretation.

Abdominal Neoplasms↗