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Biomedical subjects

M Caputo

Publications and source records attributed to M Caputo.

At least 73 records · Page 4Linked to original sources
PubMed1999

Cardiac papillary fibroelastoma: report of two cases.

We report 2 cases of cardiac papillary fibroelastoma in aortic position that were successfully treated by complete surgical excision, without damage to the aortic valve. This rare cardiac tumor can be associated with serious embolic or hemodynamic complications and therefore, prompt surgical intervention is required.

Adult↗
PubMed1998

Specific glycoconjugates are present at the oolemma of the fertilization site in the egg of Discoglossus pictus (Anurans) and bind spermatozoa in an in vitro assay.

In the egg of the anuran Discoglossus pictus, the site of fertilization is restricted to the central portion of an animal hemisphere indentation (the dimple). Previous studies showed that the acrosome reaction of D. pictus sperm is triggered in the jelly, and yet sperm arrive at the dimple surface with the plasma membrane at an early stage of vesiculation. Reactivity of the dimple surface with specific lectins suggests that fucose might be utilized as a marker of glycoproteins located at the dimple surface. In this paper, proteins of the egg surface were labeled with the membrane impermeable sulfo-NHS-biotin. Four main bands of 200, 230, 260, and 270 kDa labeled only at the dimple surface, although they were detected in the cortex of the whole egg. The 270-kDa band reacted with Galanthus nivalis agglutinin only in the cortex of the dimple, suggesting that this band is differently glycosylated according to its localization. The alpha-l-fucose-specific lectin Ulex europaeus agglutinin I was utilized both in lectin blotting and in affinity chromatography and cross-reacted with the 200- and 270/260-kDa bands. Furthermore, two polypeptides were obtained by exposure of intact eggs to lysylendoproteinase C. They were also reactive to Ulex europaeus agglutinin I. The 200- and 270/260-kDa bands were eluted from the acrylamide gels and adsorbed to polystyrene beads. An assay for sperm binding to 200-kDa glycoprotein-bound beads was developed. Sperm stuck to the beads before but not after Ca-ionophore treatment. When the beads were coated with the 270/260-kDa glycoproteins, binding occurred after ionophore treatment. In these assays, the 200- and 270/260-kDa glycoproteins competitively inhibited sperm binding to the beads coated with the corresponding glycoprotein. These results indicate that the assayed glycoproteins, located either in the glycocalyx or in the plasma membrane of the fertilization site, are involved in sperm binding.

Animals↗
PubMed1998

Metabolic differences between hearts of patients with aortic valve disease and hearts of patients with ischaemic disease.

The hypertrophic hearts of patients with aortic valve disease are likely to have metabolic demands different from hearts with ischaemic disease. In this study we measured the myocardial concentration of ATP, ADP, lactate and 16 different amino acids in left ventricular biopsies collected from patients with aortic valve disease and from patients with ischaemic heart disease. Compared to hearts with ischaemic disease, hypertrophic hearts had significantly higher concentrations of ATP, but lower concentrations of lactate, branched-chain amino acids and alanine. These differences have important implications for energy metabolism and protein turnover in the two pathologies.

Adenosine Diphosphate↗
PubMed1998

Warm blood hyperkalaemic reperfusion ('hot shot') prevents myocardial substrate derangement in patients undergoing coronary artery bypass surgery.

OBJECTIVE: A significant metabolic derangement occurs in the ischaemic-reperfused heart of patients undergoing coronary artery bypass surgery using cold blood cardioplegia. The aim of the present study was to investigate whether this effect could be reversed by complementing cold blood cardioplegia with a short terminal exposure of warm blood hyperkalaemic cardioplegia ('hot shot'). METHODS: Thirty-five patients undergoing primary elective coronary revascularisation were randomized to one of two different techniques of myocardial protection. In the cold blood group (n = 17) myocardial protection was induced using antegrade hyperkalaemic cold blood cardioplegic solution. In the hot shot group (n = 18) this was supplemented with a short exposure to hyperkalaemic warm blood cardioplegia prior to removal of the cross clamp. Intracellular substrates (ATP and amino acids) were measured in left ventricular biopsies collected 5 min after institution of cardiopulmonary bypass, after 30 min of ischaemic arrest and 20 min after reperfusion. RESULTS: Biopsies taken at the end of the period of myocardial ischaemia, when compared to control, did not show any significant change in the intracellular concentration of ATP (from 2.71 +/- 0.32 to 2.43 +/- 0.37 micromol g wet for cold blood group and from 2.6 +/- 0.3 to 2.5 +/- 0.34 micromol/g wet weight for hot shot group) or total free intracellular amino acids pool (from 33.0 +/- 1.4 to 30.0 +/- 1.4 micromol/g wet weight for cold blood group and from 34.0 +/- 1.4 to 34.5 +/- 2.3 micromol/g wet weight for hot shot group). Upon reperfusion, however, there was a significant fall in ATP (23.7 +/- 1.6 micromol/g wet weight amino acids, P < 0.05) and in amino acids (1.53 +/- 0.24 micromol/g wet weight, P < 0.05) in the group receiving only cold blood cardioplegia but not in the hot shot group (2.27 +/- 0.27 micromol/g wet weight ATP and 30.5 +/- 1.6 micromol/g wet weight amino acids). CONCLUSIONS: The data suggest that warm blood hyperkalaemic reperfusion hot shot prevents myocardial metabolic derangement seen during coronary artery surgery.

Adenosine Triphosphate↗
PubMed1998

The end of the cold era: from intermittent cold to intermittent warm blood cardioplegia.

BACKGROUND: A major reduction in the energy demand of the myocardium results from the electromechanical arrest, and cooling contributes to a lesser degree to this reduction. It is from this assumption that strategies of myocardial protection, utilizing warm blood cardioplegic induction, followed by cold cardioplegia with terminal warm reperfusion before removal of the aortic cross clamp, became established as optimal myocardial protection. Continuous normothermic perfusion 'closed the loop' by avoiding myocardial ischemia and linking warm induction and terminal reperfusion. A series of laboratory and clinical data confirmed the benefits of warm heart surgery on myocardial function and metabolism. The disadvantages of continuous warm blood cardioplegia including disturbance of the operative field, led surgeons to administer warm hyperkalaemic blood intermittently as a new cardioplegic strategy. METHODS: This review examines the laboratory and clinical data with reference to the intermittent warm blood cardioplegia, to establish its experimental basis and place in clinical practice. CONCLUSIONS: Experimental observation and clinical application have established intermittent warm blood cardioplegia as a practical, effective and cheap myocardial protection technique, particularly with reference to coronary artery surgery.

Animals↗
PubMed1998

Intermittent antegrade hyperkalaemic warm blood cardioplegia supplemented with magnesium prevents myocardial substrate derangement in patients undergoing coronary artery bypass surgery.

OBJECTIVE: The influence of the addition of magnesium on myocardial protection with intermittent antegrade warm blood hyperkalaemic cardioplegia in patients undergoing coronary artery surgery was investigated and compared with intermittent antegrade warm blood hyperkalaemic cardioplegia only. METHODS: Twenty-three patients undergoing primary elective coronary revascularization were randomized to one of two different techniques of myocardial protection. In the first group, myocardial protection was induced using intermittent antegrade warm blood hyperkalaemic cardioplegia. In the second group, the same technique was used except that magnesium was added to the cardioplegia. Intracellular substrates (ATP, lactate and amino acids) were measured in left ventricular biopsies collected 5 min after institution of cardiopulmonary bypass, after 30 min of ischaemic arrest and 20 min after reperfusion. RESULTS: There were no significant changes in the intracellular concentration of ATP or free amino acid pool in biopsies taken at the end of the period of myocardial ischaemia. However, the addition of magnesium prevented the significant increase in the intracellular concentration of lactate seen with intermittent antegrade warm blood hyperkalaemic cardioplegia. Upon reperfusion there was a significant fall in ATP and amino acid concentration when the technique of intermittent antegrade warm blood hyperkalaemic cardioplegia was used but not when magnesium was added to the cardioplegia. CONCLUSIONS: This work shows that intermittent antegrade warm blood hyperkalaemic cardioplegia supplemented with magnesium prevents substrate derangement early after reperfusion.

Adenosine Triphosphate↗
PubMed1998

Measurement of urine relative density using refractometer and reagent strips.

The relative density of urine is the ratio of its density to that of water and depends on both the number and weight of solute particles in the sample, while osmolality depends only on the number of solute particles. Water metabolism is regulated by the interaction of the renal medullary countercurrent system with the circulating levels of antidiuretic hormone and thirst. The concentration of solids in urine can be measured by weighing, hydrometry, oscillations of a capillary tube, refractometry and reagent strip. These techniques, interrelated but not identical, are commonly used in hospital laboratories and in clinical wards. We compared the results obtained in 1725 urine samples of inpatients and outpatients using an automated refractometer to those obtained using two visually read dip stick tests. The correlation coefficients (Super Aution analyser vs. Aution Sticks 10EA, Aution Sticks 10 EA vs. N-Multistix, Super Aution analyser vs. N-Multisticks were 0.663, 0.645 and 0.514, respectively) and the great dispersion of mountain plots demonstrates that different techniques are not interchangeable in the measurement of relative density. Since the results obtained after discarding the samples with pH higher than 7 and those containing glucose or protein were very similar to the ones reported above, the role of these interferents appears negligible in inducing the discrepancy.

Humans↗
PubMed1998

[Role of spiral computerized tomography in the staging of pancreatic carcinoma].

INTRODUCTION: Few pancreatic carcinomas (5-22%) are resectable at the time of diagnosis because this lesion is seldom diagnosed in an early stage. Unresectability is mainly due to the presence of metastases to the liver, peritoneum and lymph nodes and to tumor spread especially to the portal mesenteric trunk where it can invade, compress, reduce, or occlude the vessels. We investigated the diagnostic yield of multiplanar and 3D spiral CT in the assessment of pancreatic carcinoma resectability. MATERIAL AND METHODS: Twenty-seven patients with histologically confirmed pancreatic head cancer were submitted to spiral CT and color Doppler US in the Surgical Clinic I of the Bologna University. The examination results were correlated with the intraoperative findings of careful inspection and palpation and of US studies of the pancreatic mass and adjacent structures. The tumors were classified in relation to some CT parameters: tumor size (T), infiltration of the stomach (S) and/or duodenum, lymph nodes (N) or distant (M) metastases, involvement of vascular structures (V), particularly of portal or superior mesenteric vein, or superior mesenteric artery. Five grades of vascular involvement were considered. The results of these techniques were correlated with intraoperative findings from careful inspection and palpation and with US studies of the pancreatic mass and adjacent structures. RESULTS: Spiral CT revealed vascular involvement in 19 of 27 cases (70.4%): involvement of portal and superior mesenteric vein was found in 14 (73.6%), superior mesenteric vein was involved in 2 (10.6%), the portal vein in one (2%) and, finally the portal, superior mesenteric vein and superior mesenteric artery in 2 cases (10.6%). The spiral CT results were confirmed intraoperatively in 26 of 27 cases (96.3%); spiral CT did not reveal hepatic metastasis only in one case. Spiral CT with multiplanar reconstructions had very high specificity and sensitivity (100%) in the assessment of vascular involvement, while color Doppler US had the same specificity but lower sensitivity (84.2%). Spiral CT was less sensitive (80%) in the detection of liver metastases. CONCLUSIONS: We believe that spiral CT is currently the best technique for pancreatic carcinoma staging, providing useful information for correct surgical planning.

Adult↗
PubMed1997

Effect of ischaemia and reperfusion on the intracellular concentration of taurine and glutamine in the hearts of patients undergoing coronary artery surgery.

Taurine and glutamine are the most abundant intracellular free amino acids in mammalian hearts where changes in their intracellular concentrations are likely to influence a number of cellular activities. In this study we investigated the effects of ischaemia and reperfusion on the intracellular concentrations of taurine and glutamine in the hearts of patients undergoing coronary artery bypass surgery using cold crystalloid or cold blood cardioplegic solutions. Ischaemic arrest (30 min), using cold crystalloid cardioplegic solution (n = 19), decreased the intracellular concentrations (micromol/g wet weight) of taurine (from 9.8 +/- 0.8 to 7.7 +/- 0.7, P < 0.05) and glutamine (8.7 +/- 0.5 to 7.2 +/- 0.6). After 20 min of normothermic reperfusion the fall in taurine and glutamine was maintained (7.5 +/- 0.5 and 7.4 +/- 0.7 for taurine and glutamine respectively). Myocardial ischaemic arrest with cold blood cardioplegic solution (n = 16) did not cause a significant fall in tissue taurine or glutamine. However, on reperfusion there was a marked fall in the intracellular concentrations of taurine (9.4 +/- 0.5 to 6.5 +/- 0.7) and glutamine (8.0 +/- 0.7 to 5.8 +/- 0.4). The fall in amino acids was associated with a fall in ATP and a rise in tissue lactate. This work demonstrates that irrespective of the cardioplegic solution used to arrest the heart, there is a marked fall in tissue taurine and glutamine which may influence the extent of recovery following surgery. The fall in taurine is largely due to efflux whereas changes in glutamine are due to both transport and metabolism. Ischaemia, hypothermia and changes in the transmembrane concentration gradients are the likely factors responsible for the changes in tissue amino acids.

Adenosine Triphosphate↗
PubMed1997

Cardiac troponin T and troponin I release during coronary artery surgery using cold crystalloid and cold blood cardioplegia.

OBJECTIVE: To evaluate and compare myocardial protection using cold crystalloid and blood cardioplegia by measuring release of cardiac Troponin T and Troponin I during coronary artery surgery. METHODS: Forty two patients undergoing myocardial revascularization were prospectively randomised into two groups in whom myocardial protection was achieved with either antegrade cold (4 degrees C) crystalloid (CCP) (n = 21) St. Thomas' I cardioplegic solution. Serial venous blood samples were collected for measurement of cardiac Troponin T and Troponin I, prior to induction of anesthesia and at 4, 12, 24 and 48 h after removal of the aortic cross clamp. RESULTS: There were no hospital deaths in the two groups and one patient in each group suffered a perioperative myocardial infarction. Rising levels of Troponin T and Troponin I were found in all patients. Serum concentrations increased as early as 4 h after removal of the aortic cross clamp, and reached a peak at 12 h postoperatively in both groups. These levels subsequently declined, but remained higher than preoperative values at 48 h. There were no differences between the two groups with respect to serum Troponin T and I release at 4, 12, 24 and 48 h, area under the respective curves, and peak Troponin T and I release. Serum Troponin levels were significantly higher in patients with unstable angina and in two patients who suffered a perioperative myocardial infarction. CONCLUSION: Serum release of cardiac Troponin T and Troponin I is significantly raised in low risk patients undergoing myocardial revascularization. This release is similar when either cold crystalloid or cold blood cardioplegia are used. This may imply that both methods offer identical protection to the myocardium in a low risk group of patients.

Aged↗
PubMed1997

Changes in myocardial concentration of glutamate and aspartate during coronary artery surgery.

Myocardial ischemic arrest, using a cold crystalloid cardioplegic solution, decreases intracellular concentrations of glutamate (from 6.2 +/- 0.5 to 4.5 +/- 0.45 micromol/g wet weight, n = 19, P < 0.05) and ATP (from 3.0 +/- 0.4 to 1.9 +/- 0.3 micromol/g wet weight, n = 9, P < 0.05) but not aspartate. After 20 min of normothermic reperfusion, the fall in glutamate and ATP was maintained (4.5 +/- 0.52 and 2.0 +/- 0.2 micromol/g wet weight, respectively), and there was a fall in aspartate (from 1.32 +/- 0.12 to 0.9 +/- 0.1 micromol/g wet weight). Myocardial arrest with cold blood cardioplegic solution did not cause a significant fall in tissue ATP, glutamate, or aspartate. However, after reperfusion all three fell significantly. With the exception of a fall in tissue valine during ischemia with cold crystalloid cardioplegic solution and a rise in alanine during ischemia with cold blood cardioplegic solution, there were no significant changes in tissue alanine, valine, leucine, or isoleucine during ischemia or after reperfusion using crystalloid or blood cardioplegic solutions. This work documents the changes in the intracellular concentrations of important metabolites in the hearts of patients undergoing coronary artery surgery using different myocardial protection techniques.

Adenosine Triphosphate↗
PubMed1996

Tissue plasminogen activator, tissue plasminogen activator inhibitor and lipoprotein(a) in patients with coronary, epiaortic and peripheral occlusive artery disease.

In order to evaluate the relationship between the presence of atherosclerotic disease, documented by angiography, and the fibrinolytic profile, 262 consecutive patients affected by coronary (n = 90), epiaortic (n = 60) and peripheral (n = 104) artery disease have been included in the study. Twenty-two healthy subjects were used as controls for laboratory parameters determination. All patients were classified on the basis of the presence (S+) or absence (S-) of clinically significant stenosis, according to specific scoring systems. Lipoprotein(a), plasminogen activator inhibitor (PAI-1), tissue plasminogen activator (t-PA) and the PAI-1/t-PA ratio were significantly lower in controls than in coronary, epiaortic and peripheral artery disease patients. However, the levels of these parameters were not statistically different between S+ and S- subjects. These results confirm the association between lipoprotein(a), PAI-1 and t-PA levels and the presence of atherosclerotic disease independently of the arterial districts considered, while they do not appear to be directly linked to the severity of the morphological disease.

Adult↗