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Biomedical subjects

M Merli

Publications and source records attributed to M Merli.

At least 91 records · Page 5Linked to original sources
PubMed1988

A prospective study of the clinical benefits of prostacyclin in 554 cardiopulmonary bypass procedures.

Abnormal bleeding after cardiopulmonary bypass (CPB) may result from incomplete neutralization of heparin, increased fibrinolytic activity, consumption of coagulation factors, or from a reduction in the number of circulating platelets together with impairment of platelet function. Although researchers have reason to believe that hemostasis after CPB could be improved with prostacyclin (PGI(2)), a potent inhibitor of platelet aggregation, the drug's clear-cut benefits in this respect have not yet been confirmed. After conducting an initial study concerning the fate of platelets during CPB, in which we determined that PGI(2) had a protective effect, we investigated the effects of PGI(2) infusion during CPB on postoperative blood loss in 554 open-heart surgery patients, 200 of whom underwent valve replacement, 200 of whom had coronary artery bypass grafting (CABG), and 154 of whom underwent repeat valve replacement or CABG. The patients were divided into 2 groups: 277 patients (the study group) received both heparin and PGI(2) during CPB, whereas the remaining 277 patients (the control group) were given heparin alone. Of the patients who underwent surgery for the first time, those treated with PGI(2) had a reduced mean blood loss (p < 0.05 only in CABG patients) in comparison with those who received heparin alone. Of the patients who underwent redo operations, those who received PGI(2) had a nonsignificant tendency toward reduced blood loss. The mean difference in blood loss between the study group and the control group had no clinical relevance, however, because it was less than the smallest practical unit of measurement (i.e., 1 unit of blood).

Journal Article↗
PubMed1987

Composition of free fatty acids and adipose tissue triglycerides in portacaval shunted rats.

This study was designed to determine the individual fatty-acid pattern in plasma and in two adipose tissue sites of rats submitted to portacaval shunt (PCS) using the button technique. The animals were studied both in a fed state and after a 48-hour fast. Glucose, ketone bodies (KB), lactate and pyruvate levels were also measured. The results of the shunted animals were compared with pair-fed and freely fed control groups. In PCS rats, plasma free fatty-acid (FFA) levels were not significantly higher than in freely fed controls. beta-Hydroxybutyrate was significantly lower in PCS rats compared with both control groups. A 48-hour fast caused an elevation of plasma FFA and KB in all groups, but in PCS rats this increase was less pronounced. Lactate levels did not decrease during fasting in PCS rats, as they did in the control groups. PCS did not modify plasma FFA or the adipose tissue composition, neither in fed nor in fasted rats. We conclude that the PCS rats operated upon by using the button technique show mild modifications in lipid metabolism, affecting the fatty-acid composition neither in plasma FFA nor in adipose tissue.

Adipose Tissue↗
PubMed1986

Fatty acid composition of adipose tissue in patients with chronic liver disease.

In this study plasma free fatty acids and adipose tissue fatty acid composition in 10 cirrhotic patients, 5 patients with non-cirrhotic chronic liver disease and in 5 controls have been investigated. Fatty acid composition of adipose tissue in cirrhotic patients demonstrated a significant increase of 16:1 and a decrease of 18:2. Monounsaturated fatty acids represented the major fraction both in cirrhotic patients (57.5%) and in controls (55.2%). Polyunsaturated fatty acids were significantly lower in cirrhotic patients (9.1%) than in controls (14.3%). In plasma, total free fatty acids were higher in cirrhotics (732 +/- 111 microM) than in controls (319 +/- 38 microM; mean +/- SE) and the individual fatty acid profile showed a prevalence of monounsaturated fatty acid (increase of 16:1 and 18:1 and decrease of 16:0 and 18:0). The decrease in polyunsaturated fatty acids in the composition of adipose tissue triglycerides could represent a marker of long-term reduction in lipid absorption, intake and/or enhanced lipid consumption. The resemblance between plasma and adipose tissue pattern in cirrhotic patients supports the hypothesis that increased lipolysis in such patients plays the most important role in influencing plasma free fatty acid composition.

Adipose Tissue↗
PubMed1986

Splanchnic and leg exchange of free fatty acids in patients with liver cirrhosis.

Splanchnic and leg exchange of free fatty acids (FFA), glycerol and ketone bodies, as well as FFA turnover, were determined in the post-absorptive state in 8 patients with liver cirrhosis and in 6 healthy control subjects. The catheter technique was used together with tracer ([14C]oleate) infusion. The arterial concentrations of FFA, glycerol and ketone bodies were 2-6-fold higher in the patients than in the controls. The FFA turnover was 230% greater in the patients, while the fractional turnover was similar in the two groups. In the splanchnic region as well as in the leg, both FFA uptake and release were increased 2-4-fold in the patients. The fractional uptake of FFA was reduced in both areas, indicating that the augmented uptake was due to the high circulating FFA levels alone. The splanchnic production of ketone bodies was four times higher in the patients than in the controls (295 +/- 30 vs 87 +/- 11 mumol/min). The fraction of FFA converted to ketone bodies was greater (42 +/- 6 vs 20 +/- 5%, P less than 0.05), indicating that the accelerated ketone body production was a combined effect of raised FFA uptake and altered intrahepatic metabolism of FFA. The splanchnic production of glucose was reduced by approximately 50% in the patients, while the uptake of glycerol was augmented. The leg uptake of 3-hydroxybutyrate was increased 300% and the release of glycerol was 200% greater in the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1985

Aminoacid imbalance and malnutrition in liver cirrhosis.

The reason branched chain aminoacids are decreased and aromatic aminoacids increased in chronic liver failure is unclear. Branched chain aminoacids are mainly catabolised in muscles, and it is known that protein energy malnutrition may decrease the concentration of these aminoacids in plasma. In this study we have evaluated the nutritional status of a group of cirrhotics and compared it with their plasma aminoacid imbalance. Fourteen patients were considered as well-nourished and nine as malnourished. Plasma levels of branched chain aminoacids were significantly decreased and the phenylalanine increased in the malnourished group. Arm muscle circumference was significantly correlated with branched chain aminoacids. In conclusion our data suggest that malnutrition may contribute to the low levels of these aminoacids in patients with liver cirrhosis.

Journal Article↗
PubMed1984

Total and individual free fatty acid concentrations in liver cirrhosis.

The finding of high plasma free fatty acid (FFA) levels in cirrhotic patients has been attributed either to decreased hepatic clearance or to enhanced fat mobilization. To better clarify these hypotheses, total and individual FFA and glycerol levels were determined in 21 cirrhotic patients with different degrees of hepatocellular damage (evaluated by liver function tests), portal hypertension (evaluated by endoscopy and clinical signs), and nutritional status (evaluated by anthropometric and biohumoral parameters) and in 10 age- and sex-matched healthy subjects. Glucose tolerance and insulin and glucagon levels were determined in all individuals. Well-nourished and malnourished patients were identified within the cirrhotic group. Plasma FFA and glycerol concentrations were well correlated (r = 0.47, P less than 0.05), levels being significantly higher in cirrhotic individuals than in controls (746.6 +/- 46.29 SE v 359.22 +/- 40.82 mumol/L, P less than 0.001 for plasma FFA; 150.1 +/- 3.12 v 82.5 +/- 9.2 mumol/L, P less than 0.01 for glycerol). Plasma FFA and glycerol showed no correlation with the liver function test results or portal hypertension parameters. Interestingly, plasma levels of FFA and glycerol were influenced by the nutritional status, significantly higher FFA levels being observed in the well-nourished than in the malnourished patients (842.5 +/- 47.5 v 563.4 +/- 78 mumol/L, P less than 0.005). Furthermore, a positive correlation was found between plasma glycerol level and percentage of triceps skinfold (r = 0.45, P less than 0.05). No correlation was found between plasma levels of FFA or glycerol and glucose tolerance, insulin and glucagon.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Circulating anti-insulin receptor antibodies in a patient suffering from lupus nephritis and hypoinsulinemic hypoglycaemia.

A 46-year-old female patient suffering from Lupus Nephritis came to our attention in 1981 for severe recurrent hypoglycaemia; she was obliged to eat every 5-7 hr to maintain glucose values not below 1.3-1.6 mM. All known causes of hypoglycaemia were excluded by performing selective angiography of the pancreas and skull, chest and abdominal computerized tomography, as well as stimulation and suppression tests. Oral glucose tolerance, tolbutamide and intravenous insulin (0.4 U/Kg b.w.) tests demonstrated that the patient was highly insulin resistant; furthermore, studies on the patient's red blood cells suggested that her insulin receptors were completely unable to bind insulin. Studies carried out to reveal the reason for this binding inhibition demonstrated that red blood cells from normal subjects as well as adipocytes from normal rats incubated with the patient's serum did not bind insulin (50% inhibition occurring at about 1:30 serum dilution). Insulin binding inhibitors were found in the fraction of the serum precipitated by ammonium sulphate. The serum cleared of IgG fraction was unable to affect insulin binding. These data demonstrate that the serum from the female patient investigated contained anti-insulin receptor antibodies blocking the binding of insulin to its receptors. Plasmapheresis improved the patient's metabolic status. The clinical picture would suggest that recurrent hypoglycaemia was caused by anti-insulin receptor antibodies acting as insulin on target cells.

Autoantibodies↗
PubMed1982

Branched-chain amino acids vs lactulose in the treatment of hepatic coma: a controlled study.

A controlled study was carried out in two groups of 20 patients with cirrhosis of the liver and deep coma in order to compare the efficacy of intravenous branched-chain amino acid solutions in 20% glucose (group A) vs lactulose plus glucose in isocaloric amount (group B). There were 3 drop-outs from each group. Plasma amino acids and ammonia were assayed at fixed intervals throughout the 10-day observation period. Routine tests were assayed daily. Complete mental recovery was obtained in 70% of patients in group A and in 47% in group B. The difference was not significant, likely due to the lack of placebo group. With the exception of free tryptophan/all competing amino acids ratio, the modifications in plasma amino acid levels showed no correlation with the clinical course under either treatment. Ammonia, like free tryptophan, decreased significantly upon mental recovery, paralleling the clinical course throughout the study. In conclusion, branched-chain amino acids are at least as effective as lactulose in deep hepatic coma. It is suggested that branched-chain amino acids may reverse coma either by competing with brain entry of the aromatic amino acid or by metabolically decreasing free tryptophan and ammonia.

Amino Acids↗
PubMed1982

Plasma and cerebrospinal fluid amino acid patterns in hepatic encephalopathy.

Plasma and cerebrospinal fluid amino acid levels wee measured in 12 cirrhotic patients in grade 0 hepatic encephalopathy and 17 in grade 3-4 hepatic encephalopathy. In 5 of these patients amino acid determinations were performed during the evolution of the encephalopathy. No correlation was found between the degree of hepatic encephalopathy and the plasma amino acid imbalance. In the CSF of cirrhotic patients without encephalopathy, a significant increase was found in nearly all amino acids, including those known to not easily cross the blood-brain barrier; this suggests the presence of a nonspecific modification of the blood-brain barrier permeability. In patients with severe hepatic encephalopathy, the further increase only in cerebrospinal fluid aromatic amino acids and methionine levels suggests the presence of a selective stimulation of the neutral amino acid transport system across the blood-brain barrier. Finally, the good correlation between glutamine and the sum of neutral amino acids found in the cerebrospinal fluid only in the presence of encephalopathy supports the hypothesis that brain glutamine may stimulate neutral amino acid transport across the blood-brain barrier.

Adult↗
PubMed1982

[Stenosis of the left coronary trunk. Results of aorto-coronary bypass in a series of 46 patients].

Forty-six patients were operated on from 1979 to 1980 in the Department of Cardiovascular Surgery "A. De Gasperis" in Milan, to relieve left main coronary artery stenosis. There was only one death (2,1%) in a patient with "untractable angina". Three patients had per-operative infarction. No other complication were noted. The follow-up varies from 4 to 30 months: 40 patients are asymptomatic, 2 are improved, 1 patient had a recurrence of angina after 15 months. There were no deaths nor myocardial infarctions in the long-term follow-up.

Adult↗
PubMed1979

[Massive pulmonary thromboembolism: medical or surgical treatment?].

Anticoagulant-thrombolytic therapy and surgery, remain the topics of recent advances in the treatment of pulmonary embolism. The Authors have treated 3 patients with anticoagulant-thrombolytic therapy, and 14 patients with pulmonary embolectomy with cardiopulmonary bypass. By this experience, they suggest an indication for medical or surgical treatment for pulmonary embolism.

Anticoagulants↗