Biomedical subjects

V Martin-Paredero

Publications and source records attributed to V Martin-Paredero.

11 recordsLinked to original sources

PubMed1998

Fibrinogen and fibrinolysis in blood and in the arterial wall: its role in advanced atherosclerotic disease.

High plasma fibrinogen appears to be an important risk factor for the development of atherosclerosis. The aim of our study was to measure fibrinogen and fibrin degradation products (D-dimer), interleukin-6 tissue plasminogen activator, plasminogen activator inhibitor-1 and urokinase-type plasminogen activator in the plasma and arterial walls of 45 patients who had arterial surgery between April 1993 and November 1995. The arterial specimens were also examined by immunohistochemists for these same factors. The serum fibrinogen and fibrin degradation products were high in all patients, and fibrinolysis was depressed. Few leukocytes were seen in the arterial walls, which had poor fibrinolytic activity. Plasminogen-activator inhibitor activity in the wall was also reduced in the affected arterial walls. The abdominal aorta appeared to have the highest levels of fibrinogen and this may be related to its ability to form aneurysms. Fibrinogen may play an important role in the progression of atherosclerotic disease.

Aorta, Abdominal↗

PubMed1998

Hemangiopericytoma ischiorectal. Report of a case.

Hemangiopericytoma (HP) is a rare tumoral neoplasm of the soft tissues. Here, we report a case of HP that appeared in a young woman in a very uncommon location (perianal). Initially it was considered as a perianal abscess: arteriography, CT-scan and, eventually, histological studies, confirmed the diagnosis of HP. The tumoral mass was first embolized and thereafter was resected through a double approach (abdominal and perineal). One and a half years after surgery, the patient remains asymptomatic.

Adult↗

PubMed1995

Tumor embolism after pneumonectomy for primary pulmonary neoplasia.

We report a case of tumor embolism of the lower right extremity after right pneumonectomy. This is an infrequent complication and in most cases occurs during the intraoperative or immediate postoperative period. Our patient underwent surgery for primary pulmonary neoplasia (squamous cell carcinoma) and 4 hours later showed clinical signs of acute arterial occlusion in the lower right extremity. An emergency embolectomy was performed and a thrombus with tumor characteristics was extracted from the right common femoral artery. The pathologic features of this thrombus were identical to those of the pulmonary tumor.

Aged↗

PubMed1991

Renal function derangements induced by portacaval anastomosis in normal rats.

The purpose of this study was to determine the renal function derangements that portacaval shunting caused in previously normal rats. Eight rats suffered a surgical portacaval shunt (PCS) and another 8 a sham operation (SHAM). Renal function was investigated by determining urinary volume, sodium, potassium, creatinine and aldosterone excretion, in basal conditions and after sodium overload. Plasma renin concentration and urinary excretion of PGE2, 6-keto-PGF1 alpha and TXB2 were also determined in basal conditions. PCS rats showed increased urinary volume, creatinine excretion and endogenous creatinine clearance, either in basal conditions or after sodium load. After the latter, PCS animals also showed sodium retention and hyperaldosteronuria. PCS caused in basal conditions a striking diminution in urinary excretion of all prostaglandins and no changes in plasma renin. In conclusion, PCS in the normal rat caused a renal dysfunction consisting of polyuria, possibly related to ADH disfunction and an inability to manage a sodium load.

Aldosterone↗

PubMed1990

Hepatic haemodynamic changes after portacaval anastomosis in normal, cirrhotic and chronic prehepatic portally hypertensive rats.

Radioactive microspheres were used to determine the hepatic haemodynamic response to portacaval anastomosis in normal, cirrhotic and chronic prehepatic portally hypertensive rats 20 days after operation, and in normal rats 2 months after operation. After 20 days portacaval anastomosis caused a decrease in liver mass only in normal and cirrhotic animals, whereas hepatic arterial blood flow per unit of mass increased in normal (+488 per cent), cirrhotic (+191 per cent) and prehepatic portally hypertensive rats (+133 per cent). Despite these facts, animals with portacaval anastomosis showed a reduced hepatic total perfusion (arterial plus portal inflow) per unit of mass with respect to controls in normal (-53 per cent) and cirrhotic rats (-68 per cent), but not in those with prehepatic portal hypertension. Comparing studies carried out at 2 months with those performed 20 days after portacaval anastomosis in normal rats, some recovery of liver mass and total liver blood flow was observed. In conclusion, portacaval anastomosis produced a limited increase in hepatic arterial blood flow which was unable to preserve liver mass and its total perfusion in normal and cirrhotic animals. In contrast, portacaval anastomosis did not significantly alter liver mass or its perfusion in animals with chronic prehepatic portal hypertension, as both values were previously diminished in controls. Thus, the risk of liver failure after portacaval anastomosis is higher in normal and cirrhotic rats than in those with chronic prehepatic portal hypertension.

Animals↗

PubMed1990

Role of glucagon in the splanchnic and systemic hemodynamic changes induced by portal-systemic blood shunting.

Portal-systemic blood shunting is often accompanied by hyperglucagonemia and hemodynamic changes. To determine this causal relation, splanchnic and systemic hemodynamics (radioactive microspheres) and plasma glucagon levels (radioimmunoassay) were assessed in conditions of total portal-systemic shunting in portacaval-shunted (PCS) rats and in sham-operated (SO) normal rats. To compare these results, another hemodynamic study was undertaken basally and during glucagon infusion in nonoperated normal rats. PCS rats showed a threefold greater plasma glucagon concentration than SO animals (924 +/- 134 vs. 309 +/- 18 pg/ml, p less than 0.01), and they developed a hyperdynamic splanchnic circulation with higher portal venous inflow than SO rats (8.29 +/- 1.1 vs. 5.09 +/- 0.4 ml/min/100 g, p less than 0.05). Infusion of a pharmacological dose of glucagon in normal rats increased portal venous inflow (from 4.92 +/- 0.33 to 6.24 +/- 0.48 ml/min/100 g, p less than 0.05) so as to imply this hormone in the development of the hyperdynamic splanchnic circulation in conditions of portal-systemic shunting. However, the discrepancies in systemic hemodynamics between PCS and glucagon-infused rats may be a result of the different plasma glucagon levels reached in the two groups.

Animals↗

PubMed1985

Effect of captopril infusion on systemic and renal haemodynamics in conscious hypertensive rats with chronic, progressive aortic ligation.

The effect of the converting enzyme inhibitor captopril (5 mg (kg bwt)-1) on systemic and renal haemodynamics has been studied in conscious rats in which a progressive hypertension has been induced by progressive aortic ligation (AL) between the renal arteries, and in a sham-operated (SO) group. Cardiac output (CO), organ blood flow and vascular resistances have been measured using radioactive microsphaeres. Captopril infusion caused increases in CO in both groups of rats, but the increase was higher in SO (9.2 +/- 0.7%) than in AL rats (5.2 +/- 0.6%; P less than 0.005). Plasma renin concentrations were similar in both groups but increased more in AL (10.3 microIU +/- 1.0) than in SO (5.81 microIU +/- 0.62; P less than 0.05) after captopril. Captopril induced also a larger decrease in arterial pressure (36 +/- 4 mmHg), and of the pressure gradient across the stenosis (19 +/- 3) mmHg in AL than in SO rats (5.6 +/- 1.4 and 1.1 +/- 1.3 mmHg, P less than 0.005 for both cases). Vascular resistance of the kidney above the ligature decreased more in AL than in SO rats, but this difference was not observed in the other kidney. From these data it can be concluded that captopril has an acute hypotensive effect despite the normal renin levels of this model of chronic hypertension. In addition, blood flow to the high-pressure perfused kidney seems to be dependent on the increased renin production by the contralateral kidney.

Animals↗

PubMed1985

Acute renal dysfunction after major arteriography.

The incidence of acute renal dysfunction (ARD) after major arteriography was evaluated by assessment of the change in serum creatinine in 364 patients undergoing arteriography. Major arteriography was defined as abdominal aortography, abdominal aortography with lower-extremity runoff, aortic arch studies, or aortic arch plus selective carotid angiography. The influence of the volume of contrast material received, hydration, and associated risk factors was evaluated. In the entire group, the frequency of postarteriographic ARD was 7.1%. Although most patients recovered, 1.4% required renal dialysis. The frequency of renal dysfunction was significantly higher in patients with preexisting renal disease (14.8%), and 3.7% of these patients went on to require dialysis. In the total group and in those with normal renal function prearteriographically, the frequency of ARD was found to be related to the volume of iodinated contrast material received. Hydration before, during, and after angiography did not prevent this complication. Several risk factors, namely preexisting renal disease, advanced age, volume of contrast material used, type of study performed, diabetes mellitus, and coexistent heart disease were found to be associated with a statistically significant increased risk of postangiographic ARD.

Acute Kidney Injury↗

PubMed1984

Polytetrafluoroethylene grafts as the first-choice arterial substitute in femoropopliteal revascularization.

We studied a series of femoropopliteal bypass operations in which polytetrafluoroethylene (PTFE) grafts were used as the first choice, regardless of the availability of saphenous vein. From Jan 1, 1979 to Dec 31, 1982, 63 PTFE femoropopliteal bypass grafts were placed in 55 patients without exploration of the saphenous vein. Forty-three grafts were placed for limb salvage, and 20 grafts were placed for disabling claudication. Patients were followed up for nine to 53 months (average, 23 months). The operative mortality was 1.8%. There were no infections. The overall patency at 30 months was 76.1%. The 30 months' cumulative patency rate for patients with claudication was 89.3%, and there were no amputations. The cumulative 30-month patency for limb salvage was 70.1%, and there was a limb salvage rate of 81.2%. Because the 30-month results were comparable with reported series using autogenous saphenous vein, we concluded that PTFE conduits may be considered the first-choice arterial substitute for femoropopliteal reconstruction. Until longer follow-ups are available, reversed autogenous saphenous vein should probably be the graft of first choice in younger patients (less than 60 years of age) without coronary artery disease who are undergoing femoropopliteal revascularizations.

Aged↗

PubMed1983

Risk of renal failure after major angiography.

In 400 patients who underwent major aortography, acute renal dysfunction (ARD) occurred in 11.3%. Of the group with normal renal function before the procedure, 8.2% had ARD and 0.8% required dialysis. Patients with prior abnormal renal function had a 41.7% incidence of ARD, and 8.3% required dialysis as a result of angiography. Vigorous intravenous hydration was used in all patients but did not completely prevent renal problems. Two risk factors not previously emphasized were the injection site (higher risk with abdominal aortic studies) and presence of congestive heart failure requiring treatment with digoxin. Other notable risk factors included contrast load and age. These results emphasized that even with modern contrast agents and application of current concepts of treatment, there remains a risk of renal injury with major angiography.

Acute Kidney Injury↗

PubMed1983

Fate of aortic graft removal.

Reoperation to remove an aortic graft was performed in 18 patients. The need for removal was infection in the majority. A changing flora was seen in aortic graft infection with gram-negative organisms predominating. Despite a standardized approach with total graft removal, aortic closure, and extraanatomic reconstruction, amputation and mortality rates remain unacceptably high. A new approach to this problem is needed, and further trials with autogenous reconstruction appear warranted.

Aged↗