Local insulin infusion stimulates expression of plasminogen activator inhibitor-1 and tissue-type plasminogen activator in normal subjects

PURPOSE

Plasma levels of plasminogen activator inhibitor-1 are increased in obesity, hypertension, and diabetes. Their correlation with insulin levels supports the hypothesis that hypofibrinolysis may affect the development of atherosclerotic complications in patients with insulin resistance. To investigate the effect of insulin on fibrinolysis, we evaluated levels of plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) antigens during insulin infusion in the forearm vascular beds of 8 healthy subjects.

MATERIALS AND METHODS

Insulin was infused in the brachial artery of each subject to raise local venous concentrations to approximately 100 microU/mL. Blood samples were obtained from the brachial artery and vein at baseline, after 30, 60, 90, and 120 minutes of infusion, and 30 minutes after the end of the infusion.

RESULTS

Following intra-arterial infusion of insulin, forearm blood flow (mean +/- SD) increased progressively from 2.7 +/- 0.6 to 4.0 +/- 0.6 mL/dL/min (P <0.01) and did not return to baseline after the end of the infusion. Plasminogen activator inhibitor-1 balance increased (345 +/- 160 versus 8 +/- 152 fmol/dL/min, P <0.02) at 60 minutes, reaching baseline levels after the end of the infusion. After 90 minutes, tPA balance increased (40 +/- 26 versus 7 +/- 29 fmol/dL/min, P <0.01) with a profile similar to forearm blood flow.

CONCLUSIONS

Local hyperinsulinemia induces regional vasodilation and expression of PAI-1 and tPA antigens. An alteration of this physiological process could be involved in the development of hypofibrinolysis and atherosclerosis in states of insulin resistance.

Activation of coagulation in smoking and non-smoking women using a third-generation oral contraceptive containing desogestrel

The concurret use of smoking and oral contraceptives affects the hemostatic balance, thereby inducing a thrombophilic state. In order to clarify the effects of this association on the hemostatic system, the possible changes in the markers of activation of coagulation (thrombin-antithrombin III complexes and prothrombin fragment F1+2) were evaluated in 35 women given a third-generation oral contraceptive for 6 months; 13 of these women (37.1%) were mild or moderate smokers. No differences were found in basal levels of the coagulation and fibrinolytic parameters between smokers and non-smokers. During oral contraceptive administration, both F1+2 fragment and thrombin-antithrombin III complex concentrations significantly increased both in smokers and in non-smokers (p < 0.01). Fibrinogen plasma levels increased in both groups (p < 0.01). Antithrombin III activity was reduced in both groups during treatment, but the difference was significant only in smokers (p < 0.05). Although the sample size of smokers was too small to draw definitive conclusions, present results appeared to confirm previous data about the effect of the concurrent use of smoking and oral contraceptives on antithrombin III levels, but did not demonstrate any additional effect of moderate smoking on the activation of the clotting system induced by this oral contraceptive preparation.

Acetylcholine-mediated vasodilatation and tissue-type plasminogen activator release in normal and hypertensive men

Muscarinic agents release tissue plasminogen activator (t-PA) in the forearm circulation of normal subjects, but no information exists about their effect in those hypertensive patients in whom the response to endothelial-mediated vasodilators is blunted. Acetylcholine, an endothelium-dependent vasodilator and a muscarinic agonist that releases t-PA from in-vitro systems, and sodium nitroprusside, an endothelium-independent vasodilator, were infused into the brachial artery at rates calculated to cause a similar degree of vasodilatation. The study was performed in five elderly, smoking hypertensive patients in whom the clustering of detrimental factors for endothelial function permitted prediction of defective endothelial-mediated vasorelaxation, and five young, normotensive, nonsmoking male volunteers. Forearm blood flow was assessed by venous plethysmography; t-PA and plasminogen activator inhibitor 1 (PAI-1) antigen values were expressed as flow-dependent (net release, the product of venoarterial concentration gradient and forearm blood flow) or independent (absolute and fractional concentration gradients) indices. In patients, acetylcholine did not change flow and net release and concentration gradients of t-PA, suggesting that vasodilatation as such, possibly by increasing fluid shear stress, may induce t-PA release in human forearm. In normal subjects, acetylcholine and sodium nitroprusside increased t-PA antigen net release at the highest infusion rate, an effect attributable to forearm hyperperfusion, since absolute and fractional gradients did not change significantly. PAI-1 antigen did not change during either infusion in both controls and patients, indicating the absence of an endothelial pool to be mobilized acutely.

[The Hartmann procedure in colorectal emergencies. Report of 76 cases]

The Hartmann procedure has, in emergency colo-rectal surgery, many implications. The decision is based on clinical, radiological, instrumental and pathological findings. The authors report the results of 76 Hartmann's procedures performed between 1986 and 1995 and compare their results with those found in the current medical literature on the topic. In particular, they draw attention to an increased use of this procedures in colo-rectal emergencies; the morbility and mortality rates confirm the severity of the clinical cases that can be treated with this operation. To improve results the authors propose a therapeutic plan that uses a score for stratification of the risk (MPI, APA-CHE II, SSI, Hinchey); so the surgeon can choose the best surgical operation. Finally, the authors underline the importance of the principles of oncology surgery in colo-rectal cancer.

[Savariaud's maneuver in surgical procedures used for direct hemostasis in gastric hemorrhage]

The paper illustrates the manoeuvre proposed by Savariaud for the surgical exploration of the gastric cavity. The indications and results of the method are described and its considerable diagnostic and therapeutic value are underlined especially in the presence of severe gastric hemorrhage.

[Clamping the suprahepatic inferior vena cava in emergency surgery. Technical note]

In major hepatic surgery the temporary exclusion of the vena cava may be achieved using a variety of more or less complex procedures. Alternatively, for use above all in emergency surgery, the paper illustrates a method of clamping the suprahepatic inferior vena cava using a left lateral route, which is quick to carry out and undoubtedly efficient.

[Subdiaphragmatic aortic clamping in abdominal hemorrhagic emergencies]

The paper describes a technique of subdiaphragmatic aortic clamping as a provisional method to stop blood flow in abdominal hemorrhage emergencies. The numerous indications for the method and satisfactory results obtained by its use are described.

[Position anomalies of the gallbladder. Apropos of 4 cases]

Four cases of ectopic gallbladder are reported and interesting pictures presented. Related embryological, diagnostic and therapeutic aspects are then examined.

[Hemoperitoneum in segmental portal hypertension caused by pancreatic pseudocyst]

A case of haemoperitoneum during segmentary portal hypertension due to pancreatic pseudocyst is reported. After a short general review, certain physiopathological and therapeutic aspects of particular practical interest are presented.

[Microscopic analysis of saphenous veins used for aortocoronary bypass]

The Authors describe a study performed on a sample of 88 saphenous veins used as aorto-coronary bypass grafts. The patients underwent surgery in the Department of Cardiovascular Surgery of Ancona from Jan. 1981 to Dec. 1984. The morphological analysis (light and electron microscope) was conducted with a comparative method between two surgical techniques (ST). The first refers (Group I) to 1981-82, the second (Group II) to 1983-84. In Group I the veins were taken with a conventional surgical technique. In Group II the ST was performed using an atraumatic procedure, topic vasodilators, distension of the vein with autologous blood and driving pressure less than 150 mmHg, and storage of the vein in blood at room temperature. The results show that in Group II there is better preservation of the endothelial venous layer. The distending pressure of the venous graft (less than 150 mmHg) and prevention of venous spasm were statistically relevant (p less than 0.05). The AA. conclude that vein graft damage during surgery can be avoided by means of the following procedures: dissection of the vein with atraumatic technique; prevention of venous spasm with topic vasodilators; distension of the vein at pressure less than 150 mmHg.

[Infarct rupture of the heart. A clinical case operated on with success]

A 48-year-old woman was admitted for acute myocardial infarction with a normal clinical course. On the fifth day a new chest pain occurred, with low cardiac output and high central venous pressure; a pericardial effusion was present at the echocardiogram. The clinical picture improved with intensive medical care but, on the tenth day, there was a relapse with a life-threatening heart tamponade. An emergency operation was performed without previous heart catheterization. The pericardium was tense and contained about 300 ml of clots; in a wide infarcted area of the lateral wall of the left ventricle two small perforations were evident. Primary reconstruction was accomplished with interrupted stitches supported by Teflon felt strips. The bypass weaning was easy and the postoperative clinical course uneventful. We believe that the cardiac rupture is a surgical emergency; the non-invasive diagnosis is possible; the coronary angiography and revascularization must be postponed.

Neuralgic amyotrophy of the shoulder girdle. The Parsonage-Turner syndrome

From 1971 to 1983 we observed 58 cases of the Parsonage-Turner syndrome. This is a neuromuscular disease of the shoulder girdle and upper extremity which up to now has been dealt with almost exclusively in the French and Anglo-Saxon literature. The aetiology remains obscure. It is characterised by pain of acute and violent onset with paralysis and wasting of the muscles of no specific nerve root distribution. The diagnosis is based on clinical examination and electromyography. The prognosis is usually favourable. The differential diagnosis and treatment are discussed.

Changes in respiratory function in disorders of the thoracic cage. With special reference to the ventilatory mechanism and the regulation in scoliosis

After describing the clinical and functional effects of pathological changes in the thoracic cage ("mechanical syndrome" and "neuromuscular syndrome"), the authors discuss the disorders of respiratory function observed in a group of patients with poliomyelitic scoliosis. The aim was to establish the type and nature of these changes with a view to clarifying certain pathogenetic aspects. Two factors suggest that the altered geometry of the thoracic cage in scoliosis is responsible for the mechanical inefficiency of the thoracopulmonary apparatus, namely: 1. changes in respiratory function, since there was a strict correlation between the severity of the scoliosis and the degree of change in certain indices of respiratory function (vital capacity, maximum expiratory volume per second, maximum ventilation per minute); 2. changes in the regulation of ventilation, indicated by: a) good correlation between the ventilatory response to CO2 and the severity of the anatomical lesion; b) a reduction in the occlusion pressure, which is regarded as the pressure available to produce ventilation.

Stimulation of pancreatic secretion by sulpiride

Sulpiride is a nonsedative neuroleptic, pharmacologically related to metoclopramide, which has previously been shown to affect various gastric functions and to exert a beneficial effect in the treatment of duodenal ulcer. In the present study the authors investigated the effects of sulpiride on pancreatic exocrine secretion. The intravenous injection of sulpiride (100 mg) during a constant infusion of secretin (0.5 CU/kg/hr) and cholecystokinin (0.5 IDU/kg/hr) significantly increased outputs of bicarbonate and enzymes in nine healthy subjects. The increase was maximal 20-30 min after sulpiride administration and lasted for the duration of the study (1 hr). Compared to presulpiride control levels, the mean maximum percent increase was 35% for bicarbonate, 39% for lipase, and 32% for chymotrypsin. It is concluded that sulpiride augments pancreatic secretion stimulated by submaximal doses of secretin and cholecystokinin. The mechanism of this effect is unknown.

Abdominal aorta-caval fistula: treatment with aortic and caval synthetic grafts (one year follow-up)

A fistula located between the abdominal aorta and the inferior vena cava is an unusual acquired condition which necessitates prompt diagnosis and, in most instances, emergency surgical repair. The signs and symptoms are related to the size of the shunt. The classical findings are those of a continuous abdominal bruit, edema and venous pooling of the legs, wide pulse pressure, and sudden progressive high-output cardiac failure. Aortography is the definitive diagnostic procedure. However it is impractical in those situations presenting an asymptomatic fistula and contraindicated in presence of signs of progressive renal failure, where emergency surgical treatment is required. In these instances aorta-caval fistula can be correctly diagnosed by means of radionuclide aortography. The fistula can usually be repaired from within the aneurysm after endoarterectomy. Then the aortic graft replacement is completed. In rare cases the pathology at operation is such that this type of repair cannot be performed and an unexpected replacement of the inferior vena cava may be required. The purpose of this paper is to present the description of a patient in whom the diagnosis of aorta-caval fistula was confirmed by means of an isotope angiogram, followed by a successful surgical graft replacement of the abdominal aorta and a dacron tubular graft replacement of the inferior vena cava.

Emergency operations for left ventricular asynergy

Thirty-two patients were submitted to an emergency surgical procedure for left ventricular asynergy, following myocardial infarction. Indications and results are analyzed. All patients were operated upon with the aid of cardiopulmonary by-pass; an aneurysmectomy was performed in twenty-nine patients, a plication technique in three. These procedures were combined with mitral and/or aortic replacement in five patients, closure of ventricular septal defect in five, aorto-coronary saphenous vein by-pass in five. Early over all post-operative mortality was 75%: 80% in patients operated within three months from myocardial infarction, 67% in patients operated after three months from myocardial infarction.