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Biomedical subjects

M Monreal

Publications and source records attributed to M Monreal.

At least 91 records · Page 5Linked to original sources
PubMed1980

[Absence of antiDNA antibodies in the cryoglobulins of a case with sicca syndrome (author's transl)].

Cryoglobulins are serum immunoglobulins (immunocomplexes) that precipitate in the cold and redissolve on warming. Cryoglobulins from patients with several diseases showed the presence of antiDNA antibodies when previously underwent incubation in acid buffer. The possibility that antiDNA antibodies might constitute the immunocomplexes found in patients with systemic lupus erythematosus and with other connective tissue diseases is suggested. Negative findings in relation to the presence of antiDNA antibodies in cryoglobulins of a case with sicca syndrome are reported.

Antibodies↗
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Gastroduodenal ulcer incidence in patients with venous thromboembolism.

The presence of peptic ulcer disease implies a high risk of bleeding in patients on heparin therapy. We reviewed our experience with 166 consecutive patients admitted because of venous thromboembolism. Of these 166 patients, 29 were referred for upper gastrointestinal endoscopy in order to detect the presence of any lesion that might contraindicate heparin therapy. A gastric ulcer was found in 10 patients, a duodenal ulcer in 11, and gastric erosions with signs of bleeding in 3 patients. Given the unexpectedly high frequency of ulcer in these patients, an upper gastrointestinal endoscopy was routinely performed early in the course of admission in 50 consecutive patients with venous thromboembolism. A gastric ulcer was found in 5 patients (10%), a duodenal ulcer in 7 (14%), and erosions in 2. Five of these patients had an unsuspected ulcer. A case can be made for prophylactic antiulcer therapy for all patients placed on anticoagulants for venous thromboembolism. Upper gastrointestinal endoscopy is indicated in patients with ulcer symptoms, in those with a previous history of peptic ulcer disease, and perhaps, in patients developing occult blood in the stools while on treatment with anticoagulants.

Adult↗
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Secondary prevention of venous thromboembolism: A role for low-molecular-weight heparin.

BACKGROUND: After a short initial course of heparin therapy, patients with venous thrombo-embolism (VTE) require continuing anticoagulant therapy for several months after hospital discharge. At present, two small-scale studies have compared the efficacy and safety of low-molecular-weight heparin (LMWH) with warfarin in the secondary prevention of VTE. PATIENTS AND METHODS: We studied 654 consecutive patients, 202 with pulmonary embolism (PE) and 452 patients with deep vein thrombosis (DVT) of the lower limbs. 220/654 patients (34%) were considered to have some contraindications to coumarin, and were discharged on LMWH (dalteparin, Fragmin((R)), 10, 000 IU s.c. once daily). The remaining 434/654 patients were asked to choose between either coumarin or LMWH: 190 patients preferred LMWH and 244 coumarin. Patients were followed up for a 3-month (DVT patients) or 6-month (PE patients) period. RESULTS: 14/654 patients (2%) developed recurrent VTE while on anticoagulant therapy. One in every three recurrent episodes was PE (which was fatal in 2/5 patients), and half of the recurrent DVT were located in the contralateral leg. We failed to find any differences between patients receiving LMWH and those on coumarin therapy, but recurrences were more common in patients with cancer (hazard ratio: 17.15; 95% CI: 4.0-73.5; p < 0.001). 21 patients (3.3%) bled (major bleeding 5 patients; minor bleeding 16). Bleeding was more common in patients on coumarin therapy (hazard ratio: 3.14; 95% CI: 1.20-8.22; p = 0.02). CONCLUSIONS: Long-term LMWH therapy proved to be both effective and safe in the long-term treatment of VTE. Thus, we suggest long-term LMWH therapy should be considered for patients with contraindications to coumarin, or those with difficulties in coming to laboratory control.

Aged↗
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Comparative study on the antithrombotic efficacy of hirudin, heparin and a low-molecular weight heparin in preventing experimentally induced venous thrombosis.

In a random, blind study, we compared the antithrombotic potential of unfractioned heparin, a low-molecular weight heparin (LMWH) and a recombinant hirudin (r-hirudin) given subcutaneously in a jugular vein thrombosis model in rabbits. All drugs and placebo were injected subcutaneously 2 h before inducing experimental thrombosis. A good thromboprophylactic effect was obtained with either LMWH and r-hirudin as compared with placebo. By contrast, no significant differences were found between groups in bleeding time. We also found a small (non-significant) prolongation of the activated partial thromboplastin time in the r-hirudin-treated animals. As for thrombin time, r-hirudin-treated rabbits exhibited too much sensitivity, with noncoagulable end-points. In our study, r-hirudin at the dose used seemed to be as effective as LMWH is in the prophylaxis of venous thrombosis.

Animals↗
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Platelet count in acute pulmonary embolism: its relationship to recurrences.

We have prospectively studied a large series of patients with acute venous thromboembolism, trying to correlate pulmonary embolism (PE) recurrences to a number of clinical variables, and platelet count behavior. A baseline lung scan was obtained initially in every patient. Repeated chest X-ray and lung scans were obtained routinely 8 days after heparin onset. The primary trial endpoint was confirmed, clinically apparent recurrent PE; in addition, laboratory evidence of subclinical PE at the repeat scan was also considered. PE recurrences were found in 26/180 patients, and 3 out of these patients died because of massive, recurrent PE. No significant differences were found in age and sex distribution, or in the degree of deep vein thrombosis proximity between patients who did or did not develop recurrences. There were, however, differences between groups in platelet count: No differences were found in baseline counts, but mean values were significantly lower by the 8th day when recurrences had appeared (229 +/- 86 x 10(9) liters-1 versus 314 +/- 129 x 10(9) liters-1; p < 0.005). The sensitivity, specificity, positive predictive value and negative predictive value for platelet count decrease were 52, 71, 21 and 91%, respectively. Thus, platelet count cannot be reliably used for individual cases, but our findings add to the pathophysiological picture of the disease.

Acute Disease↗
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Effects of recombinant hirudin on D dimer levels before and after experimental venous thrombosis.

In a randomized, blind study, the effect of saline, a low-molecular-weight heparin (Fragmin), and a recombinant hirudin (CGP 39393) on thrombin-antithrombin (TAT) complexes and D dimer (DD) levels were studied in 60 rabbits. The drugs were always injected subcutaneously 2 h before the induction of thrombosis in the jugular vein by a combination of endothelial damage and flow reduction. A sample of blood was obtained just before surgery, and a further sample was obtained 10 min after thrombus formation. No significant differences were found in TAT plasma levels between the different study agents, either before or after thrombus development. However, 2 h after drug administration DD values were significantly lower in hirudin-treated animals (292 +/- 69 vs. 372 +/- 138 ng/ml; p < 0.05). Then, after thrombus formation, DD levels significantly increased in all three groups of animals, as compared to baseline levels. But the increase was significantly higher in hirudin-treated rabbits; DD levels after thrombus development were significantly higher in this group as compared to placebo (779 +/- 188 vs. 664 +/- 152 ng/ml; p < 0.05). There are no previous reports in the literature about the effect of hirudin on DD levels. Our hypothesis is that the effect of hirudin on DD may be the result of its ability to inhibit the thrombin-induced thrombus growth. If the thrombus is not allowed to grow then it will lyse more quickly, producing more DD and the process will not be impaired by the constant deposition of fibrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
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Effects of long-term therapy with either heparin or low-molecular-weight heparin on serum lipid levels. A prospective study.

Beside the anticoagulant and antithrombotic activity, heparin also exerts a lipolytic activity. In a prospective study on patients with venous thromboembolism and some contraindications to coumarin therapy, a low-molecular-weight heparin (Fragmin) was compared to unfractioned (UF) heparin in terms of both efficacy and safety. A secondary aim was to study the influence of both types of heparin on serum lipid levels. Sixty-six consecutive patients who were not taking concomitant treatment with lipid-lowering drugs entered the study. Patients received treatment with either UF heparin, 10,000 IU s.c., b.d., or Fragmin 5,000 IU anti-factor Xa s.c., b.d. for a period of 3 or 6 months, according to whether the initial diagnosis was deep venous thrombosis or pulmonary embolism. Each patient was followed up at 6-weekly intervals, and blood samples were obtained at discharge, and then 6 and 12 weeks after discharge. Finally, a further sample was obtained 3 months after therapy was discontinued. Total cholesterol levels increased significantly in both groups of patients: levels increased from 193 +/- 56 to 246 +/- 63 mg/dl in the UF heparin group (p < 0.001), and from 189 +/- 53 to 222 +/- 47 mg/dl in the Fragmin group (p < 0.05). The increase was mostly due to a very strong increase in HDL cholesterol levels in patients receiving UF heparin (from 46 +/- 12 to 71 +/- 23 mg/dl; p < 0.000005). Three months after discharge, HDL cholesterol levels were significantly higher in patients taking UF heparin than in patients in Fragmin (p = 0.006). By contrast, patients on Fragmin exhibited a significant increase in LDL cholesterol levels: from 112 +/- 39 to 139 +/- 37 mg/dl; p < 0.01.

Adult↗
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Preoperative platelet count and postoperative blood loss in patients undergoing hip surgery: an inverse correlation.

In a previous study we tried to assess the clinical usefulness of platelet count (PlC) to confirm whether postoperative pulmonary embolism could be suspected early. Unexpectedly, the 19 patients who subsequently developed pulmonary embolism had significantly lower mean PlC levels even before surgery. In an attempt to discover whether the preoperative PlC levels were associated with a different incidence of postoperative blood loss, we decided to retrospectively study the relationship between preoperative PlC levels and the consequences of blood loss. There were 459 consecutive patients undergoing hip surgery. After excluding 5 patients who died during the first 3 postoperative days, and 16 patients who bled from a definitive anatomic site, there were 438 patients. Blood loss was considered to be excessive when two or more of the following conditions were present: (1) total transfusion requirements exceeding 1,000 ml whole blood or 2 units of packed red cells; (2) a drop in hemoglobin level of 5 g/dl or more, and (3) a hemoglobin level below 8 g/dl at any moment during the first 8 postoperative days. Blood loss was considered to be excessive in 91 patients. Preoperative PlC levels were significantly lower in these patients as compared to patients without the condition (204 +/- 52 vs. 236 +/- 79 x 10(9) liter-1; p = 0.0002). When patients were classified according to the quartiles of preoperative PlC, the odds ratio of developing excessive blood loss was 0.69 (95% CI: 0.38-1.26) in patients in the second quartile; 0.57 (95% CI: 0.30-1.06) in the third quartile, and 0.27 (95% CI: 0.13-0.57) in patients in the highest quartile. After adjusting for age, sex, type of surgery and type of prophylaxis, the preoperative PlC levels maintained a statistically significant inverse correlation with postoperative blood loss.

Aged↗
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Platelet count and the risk of bleeding in hospitalized patients with venous thromboembolism starting anticoagulant therapy.

In a series of patients with pulmonary embolism (PE) we have previously demonstrated that the risk of recurrent PE was inversely correlated to platelet count (PlC) levels. To find out whether PlC levels were also associated to a different incidence of heparin-related bleeding complications, we report our experience with 1,103 consecutive patients with venous thromboembolism (VTE) receiving full-dose heparin therapy. Six points of clinical and laboratory information were recorded on admission and then compared to the development of bleeding: the patient's age and sex; the etiology of VTE; the type of heparin used (unfractioned, UFH, vs. low-molecular-weight, LMWH), the presence or lack of PE findings on lung scan, and the PC levels on admission. Bleeding occurred in 64/1,103 patients (6%). Patients who bled were significantly older than those who did not (72 +/- 11 vs. 64 +/- 17 years; p = 0.0005). There were no significant differences in bleeding rate according to any of the risk factors that could have predisposed to VTE, but patients treated with UFH bled significantly more frequently than those on LMWH (48/636 vs. 16/467; odds ratio: 2.30; 95% confidence interval: 1.25-4.28). Finally, mean PlC levels were significantly lower at VTE diagnosis in patients who subsequently bled (227 +/- 112 vs. 262 +/- 110 x 10(9) liters-1; p = 0.01). The logistic regression analysis confirmed that all three variables were independent risk factors for bleeding complications. This is the first study to demonstrate that PlC levels (within the normal range) are inversely correlated with the risk of heparin-related bleeding. These findings may be interest not only from the point of view of pathogenesis but also clinically, as they may be used in the decision as to which VTE patients could receive heparin therapy at home.

Age Factors↗
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[The renin-angiotensin system and anterior pituitary function: endocrine interaction or paracrine modulation?].

The identification of elements of the renin-angiotensin system and ulterior demonstration of specific cellular angiotensin II (Ag II) receptors at hypothalamic-pituitary level has suggested the possibility that these peptide play a modulatory role on anterior pituitary secretion. Recent "in vivo" and "in vitro" studies provided confirmation of a stimulatory effect of the renin-angiotensin system on growth hormone (GH) and ACTH variable. Initial experiments indicate that there is no effect on TSH and gonadotrophins secretion. Treatment with angiotensin-converting enzyme inhibitors leads to a reduction of Ag II levels that results in slight decrease of PRL and GH concentrations. However, the mechanism by which Ag II is able to modulate anterior pituitary secretion still remains obscure. Both, indirect effects mediated through changes in neuropeptide secretion or a direct interaction on pituitary cells by a paracrine or endocrine mechanism emerge as possible hypothesis to explain this regulatory function.

Adrenocorticotropic Hormone↗
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[Clinical usefulness of the glucagon test in the study of pancreatic islet cell function].

In an attempt to assess the utility of glucagon test as an index of beta cell function, we have studied the C-Peptide response to intravenous injection of 1 mg of glucagon in 77 patients with type I diabetes, 27 type II diabetics and 14 normal subjects. A significant difference between basal and glucagon-stimulated C-Peptide levels as well as a good relationship between both values were observed in all groups (r values 0.91, 0.80 and 0.89 respectively). Both basal and stimulated C-Peptide concentrations showed significant relationship with the body mass index and total cholesterol levels, whereas both parameters were negatively related to insulin requirements in type I diabetic group. Absolute C-Peptide increment was different in all groups, despite it was not related to basal C-Peptide levels. These findings confirm the usefulness of glucagon test as an investigative tool to assess the secretory capacity of beta-cell, suggesting that estimation of C-Peptide increment represents the best parameter to evaluate beta-cell reserve.

Adolescent↗
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Occlusive arterial disease as a form of presentation of homocystinuria.

Homocystinuria was first described in 1962. The disease affects several systems including the eyes, skeletal and nervous and vascular systems. We present the case of a 28-year old woman who presented with a severe occlusive arteriopathy. Screening for the most usual causes of arterial disease in young patients was negative, but a study of aminoaciduria and column chromatography confirmed the diagnosis of B6-responsive homocystinuria. Although it was necessary to amputate her left leg, the patient remains asymptomatic 16 months after B6 therapy was started.

Adult↗
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[Heparin-induced hemorrhage in the treatment of venous thromboembolism].

Retrospective study about the frequency of hemorrhagic complications (258 patients) in the treatment of venous thrombosis and/o pulmonary embolism, with heparin. Heparin was intermittently administered by endovenous way and controlled during the ten first days. Mostly of the big hemorrhages happened between the seventh and the tenth day, in digestive and urinary system mainly.

Hemorrhage↗
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[Compression of the iliac vein and occult neoplasm].

Three cases demonstrating the possible venous system compression by some neoplasias, feigning an nonexistent thrombosis, are presented. Author stands out the fitness of to investigate possible neoplasias in thrombosis without apparent causality.

Adult↗