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Biomedical subjects

M Caputo

Publications and source records attributed to M Caputo.

At least 55 records · Page 3Linked to original sources

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↗

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↗

[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↗

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↗

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↗

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↗

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↗

The insulin resistance in women with hyperandrogenism is partially reversed by antiandrogen treatment: evidence that androgens impair insulin action in women.

To assess whether androgen excess per se might impair insulin action, insulin sensitivity was measured by a two-step (20 and 80 mU/m2.min) hyperinsulinemic euglycemic clamp combined with indirect calorimetry and tracer glucose infusion in 43 women (13 obese and 30 nonobese) with normal glucose tolerance and clinical evidence of increased androgen action (hirsutism and/or polycystic ovary syndrome) as well as 12 age- and body mass index-matched healthy controls. Hyperandrogenic women were studied basally and after 3-4 months of antiandrogen treatment with 3 different drugs: spironolactone (n = 23), flutamide (n = 10), or the GnRH agonist buserelin (n = 10). Six women given spironolactone were also reexamined after 1 yr of therapy. At baseline, insulin-mediated glucose uptake was lower in hyperandrogenic women than in controls (by ANOVA, F = 14.3; P < 0.001). Insulin resistance was observed in both ovarian and nonovarian hyperandrogenism, as distinguished by acute GnRH agonist testing. After antiandrogen therapy, insulin action on glucose metabolism significantly increased for both the patients as a whole (F = 7.4; P < 0.01) and each treatment group separately. However, insulin action remained lower than in controls and showed no further improvement in patients reevaluated after I yr of treatment. Increases in both oxidative and nonoxidative glucose metabolism accounted for the improvement in substrate disposal induced by antiandrogen drugs. The increase in the effectiveness of insulin was greater in the lean subjects, whereas the change was small and not statistically significant in the obese women. Response to treatment was more pronounced in women with nonovarian hyperandrogenism, particularly at the low insulin infusion rate. Endogenous glucose production in hyperandrogenic patients was similar to that in healthy women and was unaffected by therapy. In conclusion, antiandrogen treatment partially reversed the peripheral insulin resistance associated with hyperandrogenism regardless of which antiandrogen was used. These data strongly suggest that in women, androgen excess per se contributes to impairment of insulin action.

Adult↗

Renal effects of prolonged antihypertensive treatment with diltiazem.

The effects of diltiazem (DTZ) treatment on blood pressure, renal function and renal hemodynamics over a six week period of therapy were evaluated in 14 adult patients with mild to moderate hypertension. Their creatinine clearances were 64 to 153 ml/min. After a week of treatment with placebo, DTZ was administered orally at a daily dose of 120 mg b.i.d. Blood pressure decreased from a mean value of 152/99 mm Hg (+/-13/6 SD) up to 144/91 (+/-17/8, P < 0.005) in the supine position and from 149/107 (+/-14/9) to 141/96 (+/-16/9, P < 0.005) in standing position. Heart rate decreased from 74 (+/-9) to 69 (+/-8). Plasma urea, creatinine, uric acid and their clearances as well as GFR and ERPF remained stable throughout the trial. Plasma glucose increased from 81 (+/-15) mg/dl to 98 (+/-30, P < 0.05) and plasma potassium decreased from 4.0 mEq/liter to 3.7 (+/-0.3, P < 0.005). Plasma cholesterol and triglycerides were unmodified. DTZ is an effective antihypertensive agent which does not significantly affect renal function. The effects on plasma glucose and potassium require periodical check-ups of these parameters.

Adult↗

SPECT and epilepsy with continuous spike waves during slow-wave sleep.

Ten cases of epilepsy with continuous spike waves in slow-wave sleep (CSWS) were evaluated using single photon emission computed tomography (SPECT); in eight patients the EEG paroxysmal abnormalities showed a predominant localization. SPECT carried out using 99mTc-HMPAO allows study of cerebral blood flow (CBF); the examination was performed during phases of drowsiness and the results compared to the EEG data. In four cases SPECT revealed areas of low CBF in sites corresponding to those of the prevalent EEG discharges; in two cases the areas of hypoperfusion did not correspond to those indicated by the EEG; lastly, in four cases SPECT results were negative. The areas of hypoperfusion were predominantly located in the frontal, temporal, and parietal regions. Furthermore, the percentage of positive SPECT results was significantly higher (five cases out of six) in the group in which the CSWS phase was prolonged for at least 1 year, compared to the group in which this phase lasted less than 1 year. Thus, in this type of epilepsy, SPECT reveals focal cortical areas of decreased CBF which correlated generally to the predominant sites of EEG abnormalities. A longer duration of the CSWS phase seems to be associated with a more significant cortical disorder, documented by the presence of areas of hypoperfusion.

Adolescent↗

[The role of the radiological hemithorax examination in closed trauma of the chest].

January, 1992, to September, 1994, a hundred and seventy-eight blunt chest trauma patients were examined with plain chest films and detailed rib studies. The patients were subdivided into three groups according to: a) the presence/absence of rib fractures correlated with clinical data; b) the depiction of rib fractures and/or thoracic complications; c) treatment customization in the presence/absence of rib fractures. In our series of patients the clinical data and the presence of rib fractures were poorly correlated. The detection rates of minor and major complications were also investigated on plain chest films and detailed rib studies. Plain chest films most frequently depicted the complications requiring conservative or surgical management and gave the indication for further imaging investigations. The detailed rib studies of the involved hemithorax yielded no further information useful to therapy except in few cases: and should therefore be limited to the cases exhibiting complications on chest films, which may benefit from surgical fixation. The accurate study of rib fractures is paramount in the cases where legal action may be undertaken.

Humans↗

[Incidence of dilatation of residual cystic duct in liver transplantation. Our experience with 152 cases].

In our series of patients, we studied the incidence of residual cystic duct mucocele, which is still considered a rare complication in orthotopic liver transplantation (OLT). 152 OLTs were performed in 138 patients in the II Surgery Dept. of Bologna University, May 1986 to June 1994; a termino-terminal choledocho-choledochal anastomosis was performed in 145 of them. A choledocho-jejunal anastomosis was performed in other 7 patients. In 3 patients we observed an anechoic ovoidal structure localized just before the portal vein, near the main bile duct (MBD). Then, we monitored the evolution of this finding by ultrasonography (US), Doppler US, CT and CT-cholangiography. Integrated imaging, clinical and surgical data, led to the diagnosis of non-obstructive mucocele of residual cystic duct in OLT. To date, this complication has not led, on our series, to the necessity of new surgical procedures for cholestasis by MBD compression, which is in disagreement with literature data. In our series, the incidence of residual cystic duct mucocele is 2%, which is a higher value than those reported in the literature, suggesting that this condition be investigated carefully as a non-rare complication in OLT.

Adult↗