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Biomedical subjects

M Monreal

Publications and source records attributed to M Monreal.

At least 19 recordsLinked to original sources
PubMed1992

Deep venous thrombosis and the risk of pulmonary embolism. A systematic study.

The influence of several diseases and clinical conditions on the presence of pulmonary embolism (PE) in a large series of patients with deep venous thrombosis (DVT) in the lower extremities was analyzed prospectively. Lung scan findings from a series of 434 consecutive patients with DVT (with and without symptoms of PE) were studied and then correlated to five clinical variables: age, sex, elapsed time since clinical symptoms had appeared in the leg to diagnosis, degree of proximity of venous thrombus, and the presence or not of several risk factors that could have predisposed to thrombus development. According to scintigraphic findings, 164 patients were considered to have PE (asymptomatic in 76 of them), while 200 patients were classified as having only DVT. Lung scan was considered to be indeterminate for PE in 70 patients, and they were not included in the study. No differences were found in terms of age, sex, interval of time elapsed since onset of symptoms to diagnosis, or in the degree of proximity of the thrombus. However, several differences between groups were found when comparing the presence or absence of several predisposing factors for thrombosis: DVT developing in immobilized patients was associated with a significantly lower incidence of PE as compared with nonimmobilized patients (p = 0.005). Conversely, patients with a history of venous thromboembolism (VTE) had a significantly higher rate of embolism (31/51 vs 133/313; p = 0.01). On logistic regression analysis, a history of VTE showed a statistically significant association with more than a twofold higher risk of having PE for patients with such an antecedent. Our findings suggest that different pathophysiologic pathways could perhaps explain differences in embolic potential.

Causality↗
PubMed1992

Effects of inhaled platelet activating factor on bronchial responsiveness in patients with symptomatic and asymptomatic pulmonary embolism.

To determine the possible role of platelet-activating factor (PAF) in pulmonary embolism (PE), the reactivity of the airways to inhaled PAF, using doses ranging from 6.25 to 400 micrograms, was examined in 24 patients with a past episode of PE. Twelve of these patients had experienced acute respiratory insufficiency during the episode (with or without additional symptoms). None of the remaining 12 patients had experienced any respiratory symptoms during the PE episode. Diagnosis was established by means of a ventilation-perfusion lung scan performed when admitted to the hospital because of deep venous thrombosis (DVT) in the lower limbs. Nonspecific bronchial reactivity as measured by the response to bronchoprovocation testing with methacholine showed no significant differences between both groups. PAF caused a dose-dependent bronchoconstriction defined by at least a 35 percent decrease in specific airway conductance (SGaw) in all patients. The average dose of PAF needed to decrease SGaw 35 percent was significantly lower in patients who had had a symptomatic PE than in those with asymptomatic PE (p = 0.011). This finding suggests that patients who suffered from symptomatic PE may present a greater airway reactivity to inhaled PAF. This different behavior might explain the existence of some of the respiratory symptoms of PE, which could be attributed to PAF-related effects. However, additional studies are needed to evaluate the role of PAF in PE.

Administration, Inhalation↗
PubMed1991

Occult cancer in patients with deep venous thrombosis. A systematic approach.

The authors prospectively studied 113 consecutive patients with deep venous thrombosis of the lower extremities to determine the most appropriate workup study for searching for a hidden cancer. After a careful physical examination, the following routine tests were performed: erythrocyte sedimentation rate (ESR), whole blood counts, biochemistry, carcinoembryonic antigen (CEA) levels, chest radiograph, upper gastrointestinal endoscopy, abdominal ultrasound and computed tomography (CT) scan. If a malignant lesion was suspected, further appropriate studies were performed. After discharge, periodic follow-up was performed on all patients in the outpatient clinic. A malignant neoplasm was detected in 12 patients. Of these 12 patients, six were asymptomatic with the exception of experiencing thrombophlebitis. Cancer was found more commonly in patients with idiopathic deep vein thrombosis (DVT) (7 of 31 versus 5 of 82 patients with secondary DVT; P = 0.012), and in those patients with abnormal lactic dehydrogenase (LDH) levels (6 of 23 versus 6 of 90; P = 0.007). Abnormal CEA levels allowed diagnosis of two cases of colonic cancer (on colonoscopy). Both ultrasound and CT scan of the abdomen showed two cases of urinary bladder carcinoma at a very early stage. Furthermore, two cases of adenomatous polyps in colon were found, a condition considered by most authors to be a colorectal cancer precursor. In addition, there were five patients with large benign pelvic tumors, and two patients with absent inferior vena cava. The most striking finding was that some cases of cancer were at a very early stage. It was concluded that blood cell counts, LDH, CEA, chest radiograph, and abdominal ultrasonography (or CT scan) should be routinely performed on all patients with deep venous thrombosis (particularly those with idiopathic DVT). Malignancy would not have been recognized in some patients if these tests had not been performed.

Adult↗
PubMed1991

Role of granulocytes in the development of venous thrombosis in patients with hip fractures.

In a previously reported study we compared the use of a low-molecular-weight heparin (LMWH) and conventional heparin in the thromboprophylaxis of patients with hip fracture. In an attempt to establish additional factors which could aid in predicting the development of deep-venous thrombosis (DVT), we retrospectively studied several clinical and laboratory variables and found that granulocyte count on admission was higher in patients without subsequent postoperative DVT. Forty additional patients were included in a further prospective study in order to validate our previous findings. 38% of patients who developed DVT had a granulocyte count lower than 9,500/microliters, whereas only 18% of those patients with DVT had a count higher than 9,500/microliters. These figures imply a positive predictive value of 38% and a negative predictive value of 82%. We suggest that granulocytes could play a role in the development of DVT and preoperative granulocyte count may be used to detect a high-risk population for DVT after a hip fracture.

Adult↗
PubMed1991

Comparative study on the antithrombotic efficacy of four low-molecular-weight heparins in three different models of experimental venous thrombosis.

In a randomized, blind study, both the antithrombotic efficacy (reduction of thrombus weight) and potency (anti-Xa activity) of several commercially available low-molecular-weight heparins (LMWHs) were compared with those of unfractioned heparin (UFH) and placebo. Three different thrombogenic challenges were used: venous thrombosis was induced by direct endothelial damage in 60 New Zealand rabbits (group I), intracarotid injection of bovine thrombin in an additional series of 60 rabbits (group II), or after inferior-vena-cava ligature in 60 Wistar rats (group III). The drugs were administered subcutaneously 2 h before surgery in a blind fashion. The doses recommended for clinical practice were used (adjusted by body weight), except in group II animals, in whom doses were doubled. No differences were found between UFH and most LMWHs in terms of reduction of thrombus weight in group I animals. But UFH showed a weaker antithrombotic efficacy in the other two models. Similarly, one of the LMWHs used (Clexane) proved to be not as effective as the remainder. However, only clinical studies will provide enough information to verify these differences. Additionally, our findings confirm that the antithrombotic efficacy of a given drug differs according to the stimulus used to induce venous thrombosis.

Animals↗
PubMed1991

Acute gastroduodenal lesions in patients with venous thromboembolism. Identification of patients at risk.

The prime complication of heparin therapy is bleeding, and the gastrointestinal tract is the most common site of bleeding in patients treated with heparin. We recently reported that gastroduodenal lesions are common in patients admitted because of acute venous thromboembolism, and now we present our experience in a larger series of patients. The aims of the study were to try to validate our previous findings and to identify clinical factors that could increase the likelihood of having an acute, potential bleeding lesion in the gastroduodenal tract. Upper gastrointestinal endoscopy was performed on admission in 155 consecutive patients with acute venous thromboembolism (118 with deep vein thrombosis, 37 with pulmonary embolism). Acute lesions (both peptic ulcers and diffuse erosions) were found in 19 of 118 patients (16 percent) with venous thrombosis, and in 14 of 37 patients (38 percent) with pulmonary embolism (p = 0.005). When only patients with pulmonary embolism were considered, lesions were more commonly found in men, and in patients with severe hypoxemia on admission. When considered overall, only the timing of endoscopy was statistically significant; acute lesions were more commonly found when endoscopy was performed early after admission. No significant differences were found in terms of age, sex, smoking habits, alcohol intake, concomitant drug ingestion, comorbid diseases, or previous history of ulcer. The very high incidence of upper GI tract lesions in these patients will have long-term diagnostic/therapeutic implications which cannot be ignored. Who should receive prophylactic H2 blockers and for how long remains to be determined.

Acute Disease↗
PubMed1991

Platelet count and venous thromboembolism. A useful test for suspected pulmonary embolism.

We have previously reported that patients with deep vein thrombosis (DVT) and scintigraphic evidence of pulmonary embolism (PE) had a fall in platelet count, as compared with their levels before thrombosis had developed. Otherwise, no changes were found in DVT patients without embolism. We recently conducted a prospective study with a larger series of patients and studied platelet count behavior in 189 consecutive patients with acute venous thromboembolism (VTE) in whom a baseline blood cell count was available (obtained before thromboembolism developed). We found no significant differences in baseline platelet counts between groups. However, at the time of VTE diagnosis the analysis of variance demonstrated that mean platelet count was significantly higher in patients without embolism as compared with PE patients (p less than 0.001). On the other hand, no differences were found between patients with silent PE and those with clinically obvious PE. When patients with postoperative VTE and those with nonpostoperative VTE were analyzed separately, mean platelet count increased only in postoperative DVT patients without embolism (p less than 0.001). In the absence of a previous intervention, DVT did not produce any change in platelet count, while PE significantly reduced platelet number (p less than 0.008). In DVT patients without respiratory symptoms of embolism, we suggest that a lung scan should be performed when platelet count is lower than baseline value. For patients with a higher count, the probability of finding PE is very low, and scintigraphy is not cost-effective.

Adolescent↗
PubMed1991

Upper-extremity deep venous thrombosis and pulmonary embolism. A prospective study.

We prospectively evaluated the prevalence of pulmonary embolism (PE) in 30 consecutive patients with proved deep venous thrombosis (DVT) of the upper extremity. Ten patients (seven male and three female; mean age, 43 years) had primary DVT, and 20 patients (14 male and six female; mean age, 52 years) had catheter-related DVT. Ventilation-perfusion lung scans were routinely performed at the time of hospital admission to all but one patient (one patient was critically ill, and he died four days after DVT diagnosis because of massive PE). Lung scan findings were normal in nine of ten patients with primary DVT, and they were indetermine in the remaining patient. By contrast, perfusion defects were considered highly suggestive of PE in four patients with catheter-related DVT; two patients had indeterminate lung scans, and 13 patients had normal scans. We conclude that PE is not a rare complication in upper extremity DVT, and that patients with catheter-related DVT seem to be at a higher risk.

Adult↗
PubMed1991

[Treatment with octreotide (SMS 201-995) in a case of intestinal carcinoid tumor].

Over the past few years the usefulness of some somatostatin's analogues in the treatment of intestinal tract endocrine tumors has been demonstrated. Notwithstanding, the results obtained are variable. The case of a carcinoid tumor with a hepatic metastasis is presented and its clinical as well as its biochemical and its morphological results are evaluated after treatment with octreotide over a seven months period. It is important to highlight the great clinical improvement obtained at the beginning of treatment. Treatment was not effective in the control of tumor progression. After the injection of such a drug, a decrease in serotonin and 5-hydroxy-indoleacetic acid serum levels was observed as well as a reduction in the urinary metabolite. It is concluded that octreotide is very useful for the symptomatic treatment of carcinoid syndrome.

Aged↗
PubMed1991

[Segond's fracture at the knee level].

Ten patients out of twelve with Segond's fracture were treated surgically, checking the existence of an injury to the anterior cruciate ligament and in the remaining two were confirmed clinically and by radiology. Some controversy has existed regarding just what type of injury was being treated, and if it was associated or not with a ligament injury. In that series the injury was defined exactly, and we confirm the opinion of authors such as Insall, who consider it to be a pathognomonic sign of injury of the anterior cruciate ligament.

Adolescent↗
PubMed1990

Insulin requirements and residual beta-cell function 12 months after concluding immunotherapy in type I diabetic patients treated with combined azathioprine and thymostimulin administration for one year.

An increase in clinical and functional remissions with immunosuppression, as well as abnormal T-cell function, in Type I diabetic patients has been reported in the early stages of diabetes. A controlled trial with azathioprine and thymostimulin in separate and combined administration was performed in 45 recently diagnosed Type I diabetic patients. Phenotyping of the T-lymphocyte subsets, levels of CD25 positive cells and interleukin-2 production by patients' lymphocytes, as well as remission rate and stimulated C-peptide levels, were serially assessed. Remission was defined as mean weekly glycemic profiles less than or equal to 7 mmole/l, serial HbA1 values in the normal range and no insulin requirements for at least 2 consecutive months. At 3,6,9 and 12 months of immunotherapy, remission occurred respectively in 0%, 8.3%, 16.6% and 0% of the conventionally treated diabetic controls and in 42.8%, 50%, 42.8% and 36.2% of the subjects submitted to combined azathioprine and thymostimulin administration. Patients receiving azathioprine or thymostimulin alone did not achieve better remission rates than controls. C-peptide levels were significantly higher (above 0.6 pmol/ml) in patients with remission than in those not in remission (P less than 0.02) throughout the trial. Excessive interleukin-2 production in recently diagnosed diabetics returned to normal levels in patients in remission. In the group receiving combined therapy, 38.5%, 25% and 23% were still in clinical remission at 6, 9 and 12 months after drug withdrawal. Twelve months after stopping treatment, patients who had remitted exhibited significantly lower insulin requirements and greater endogenous insulin secretion than those who had not remitted; the former also maintained near normal glycemic control. No side effects were detected except mild and transient leucopenia in a reduced number of patients receiving azathioprine. Remission was related to the time of beginning immunotherapy after the onset of diabetes (17.1 +/- 7 vs 42.5 +/- 15 days; P less than 0.01) and to age (17.7 +/- 5.6 vs 13 +/- 7 years; P less than 0.05). Interleukin-2 production seems to be negatively associated with clinical remission in the early stages of diabetes. Results suggest a complementary effect of the drugs used in this study that may enhance long-term remission in recently diagnosed Type I diabetic patients.

Adolescent↗
PubMed1990

Heparin-related osteoporosis in rats. A comparative study between unfractioned heparin and a low-molecular-weight heparin.

In an animal model, the effect of a high dose of conventional heparin (2 IU/g s.c. twice a day) and a low-molecular-weight heparin (LMWH; Fragmin, 1 anti-Xa U/g once a day) was compared with that of placebo on the mineral bone mass in the femur of rats. After 33 days of treatment no differences were found in the weight of the femur. But heparin-treated rats exhibited a lower density (1,249 +/- 0.046 g/ml as compared with that in control rats (p = 0.00007) and also in LMWH-treated rats (p = 0.001). Similarly, statistically significant differences have been found in ash contents. They were higher in control rats than in heparin-treated rats (p = 0.0002), and also slightly higher than in LMWH-treated rats (p = 0.01). Our findings suggest that LMWH may have a lower osteopenic effect than that of conventional heparin.

Animals↗