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Biomedical subjects

R Gilabert

Publications and source records attributed to R Gilabert.

At least 37 records · Page 2Linked to original sources
PubMed1998

Clinical events after transjugular intrahepatic portosystemic shunt: correlation with hemodynamic findings.

BACKGROUND & AIMS: Transjugular intrahepatic portosystemic shunt (TIPS) procedures are increasingly being used, but the relationship between the hemodynamic effects of TIPS and the clinical events on follow-up remains undefined. Hence, we have investigated the hemodynamic correlations of portal hypertension-related events after a TIPS procedure. METHODS: Prospective follow-up of 122 cirrhotic patients who had a TIPS procedure performed because of variceal hemorrhage was conducted. RESULTS: The portacaval pressure gradient (PPG) significantly decreased after the TIPS procedure (from 19.7 +/- 4.6 to 8.6 +/- 2.7 mm Hg; P > 0.001), but increased thereafter and at rebleeding (n = 25) was > 12 mm Hg in all patients (18.4 +/- 4.6 mm Hg). Twenty-six patients developed ascites; the PPG (measured in 19) was always > 12 mm Hg. Increasing the PPG to > 12 mm Hg occurred very frequently (83% at 1 year). Within 1 year, 77% of patients underwent balloon angioplasty or restenting. However, 80% had again a PPG of > 12 mm Hg 1 year after reintervention. Hepatic encephalopathy developed in 31% of patients at 1 year; 21 of 23 patients had a PPG of < 12 mm Hg. CONCLUSIONS: Total protection from the risk of recurrent complications of portal hypertension after a TIPS procedure requires that the PPG be decreased and maintained < 12 mm Hg. However, reintervention will be required in most patients within 1 year and again the second year. On the other hand, such portal decompression is associated with an increased risk of hepatic encephalopathy.

Adult↗
PubMed1998

Coagulation and fibrinolytic parameters in normal pregnancy and in pregnancy complicated by intrauterine growth retardation.

The objective of this article is to evaluate the plasma levels of coagulation and fibrinolysis parameters in the third trimester of gestation and 72 hr postdelivery. Antithrombin III (ATIII), thrombin-antithrombin III complexes (TAT), heparin cofactor II (HCII), protein C (PC), protein S (PS), tissue plasminogen activator (t-PA), D-dimer, and plasminogen activator inhibitors (PAI-1 and PAI-2) levels in uncomplicated pregnancies and in pregnancies complicated by intrauterine growth retardation (IUGR) have been determined. Normal pregnant women (n = 63) and women whose was complicated by IUGR (n = 10) formed the study population. Coagulation and fibrinolysis parameters were estimated using commercial tests. There were no differences in ATIII, HCII, and PS levels between normal and IUGR pregnancies. TAT, t-PA, and D-dimer levels were higher in IUGR pregnancy than in the uncomplicated pregnancy group. PAI-1 and PAI-2 were found depressed in IUGR pregnancy when compared with normal pregnancy. Changes in coagulation and fibrinolytic systems occur in plasma of women with pregnancies complicated by IUGR. The results suggest an activation of the coagulation system in pregnancies complicated by IUGR. Reduced PAI-2 and high TAT levels correlate with birth weight. In IUGR pregnancies a hypercoagulative state with hyperfibrinolytic compensatory mechanisms is suggested.

Adult↗
PubMed1998

Coagulation and fibrinolysis parameters in normal pregnancy and in gestational diabetes.

The changes in coagulation and fibrinolysis parameters during pregnancy, delivery and 3 days after delivery were evaluated in normotensive and gestational diabetes pregnant women. Normal pregnant women (n = 60) and pregnant women with gestational diabetes (n = 15) formed the study population. Coagulation and fibrinolysis parameters were estimated using commercial tests. Antithrombin III, thrombin-antithrombin III complexes, heparin cofactor II, protein C, protein S, tissue plasminogen activator, (t-PA) D-dimer and plasminogen activator inhibitor (PAI-1 and PAI-2) activities in normal and gestational diabetes pregnancies were determined. Thrombin-antithrombin III complexes increased and coagulation inhibitors decreased in gestational diabetes. Plasminogen activator inhibitors remained unchanged and t-PA levels increased in gestational diabetes.

Adult↗
PubMed1998

Has double-phase MIBI scintigraphy usefulness in the diagnosis of hyperparathyroidism?

The usefulness of double-phase parathyroid technetium-99m-MIBI scintigraphy for the detection of hyperplastic parathyroid tissue has been described. The aim of the present study was to establish the effectiveness of this new technique in the morphological and functional assessment of parathyroid glands in patients with different types of hyperparathyroidism. We performed 99mTc-MIBI scintigraphy (MIBI) and neck ultrasonography in 38 patients with primary (n=16) or secondary (n=22) hyperparathyroidism. All patients underwent surgical neck exploration, removing a total of 84 parathyroid glands. Before and after surgery, blood intact parathyroid hormone (iPTH) was measured peripherally and in both the right and left internal jugular veins. In patients with primary hyperparathyroidism, ultrasonography showed one enlarged gland in 11 cases (69%), while MIBI was positive in 15 (94%) (including two ectopic glands). The sensitivity of MIBI (93%) was greater than that of ultrasonography (68%), with a similar specificity (100 and 97%, respectively). In patients with secondary hyperparathyroidism, there was a discrepancy between both imaging modalities in 29 glands (33%). The sensitivity of both techniques was similar (41 and 54%, respectively), with the same specificity (89%). There were more difficulties in detecting the upper than the lower pathological glands. MIBI reflected more accurately the functionality of the glands, and ultrasonography has a better correlation with the volume and weight. In conclusion, Tc-99m-MIBI scintigraphy is a good technique to identify parathyroid hyperfunctioning tissue in cases of primary hyperparathyroidism and to detect ectopic glands, but it does not give significantly better results than conventional ultrasonography in patients with secondary hyperparathyroidism.

Female↗
PubMed1998

Endothelial cell markers and fibrinopeptide A to D-dimer ratio as a measure of coagulation and fibrinolysis balance in normal pregnancy.

OBJECTIVE: Changes in hemostatic system were evaluated in healthy pregnant women. METHODS: Blood was sampled in the 1st, 2nd and 3rd trimesters of gestation, during delivery and 3 days postpartum and plasma factors were measured using commercial tests. RESULTS: Thrombin-antithrombin III complexes, fibrinopeptide A and D-dimer were higher during pregnancy. The endothelial cell markers, fibronectin and tissue factor, remained within the normal reference values in the healthy nonpregnant population. This result suggests no endothelial injury and shows no activation of extrinsic coagulation pathway during pregnancy. The balance coagulation/fibrinolysy is maintained during pregnancy and delivery, as shown by the ratio fibrinopeptide A/D-dimer, however, a tendency towards coagulation process is developed in the early puerperium.

Adult↗
PubMed1998

Heparin cofactor II: a new marker for pre-eclampsia.

The plasma levels of heparin cofactor II were determined in pregnant women who were either normotensive, or had essential hypertension, gestational hypertension or pre-eclampsia during the third trimester and 72 h after delivery. Heparin cofactor II levels in the pre-eclampsia group were depressed. The clinical relevance of this finding is the potential utility of heparin cofactor II plasma levels in the differential diagnostic between non-proteinuric hypertension and pre-eclampsia.

Adult↗
PubMed1997

Facility changes mediated by cAMP in the bovine anterior segment in vitro.

The aim of this study was to investigate the influence of substances that increase intracellular cAMP levels on the aqueous humor outflow facility (C) of isolated bovine anterior segments. Anterior segments were perfused in vitro at a constant pressure of 10 mmHg for 270 min with a general protocol as follows: 90 min control perfusion with DMEM, 90 min of experimental perfusion with DMEM containing the test drug(s), and 90 min of postdrug-perfusion with DMEM. C was calculated as the ratio between the rate of medium inflow (microliter/min) and the perfusion pressure (mmHg). Anterior segments can be perfused in vitro for up to 5 hr without significantly modifying their C. The addition of epinephrine, forskolin, dibutyryl-cAMP or isobutylmethylxanthine to the control perfusion medium elicited a significant increase of C. If, during isobutylmethylxanthine perfusion, forskolin or epinephrine was added, C increased significantly. Finally, perfusion with indomethacin prior to addition of epinephrine prevented the increase of C induced by epinephrine. Epinephrine, the adenylate cyclase activator forskolin, the cAMP analog dibutyryl-cAMP, and the phosphodiesterase inhibitor isobutylmethylxanthine all increase aqueous facility. It seems reasonable to suspect that the cAMP system is involved in epinephrine's effects on bovine trabecular meshwork cells. Moreover, the complete inhibition by indomethacin of the outflow facility increase induced by epinephrine suggests that prostaglandins may be involved in the outflow facility mechanisms related to adrenoreceptor stimulation of trabecular meshwork cells.

1-Methyl-3-isobutylxanthine↗
PubMed1997

Enrichment of the fraction of nociceptive neurones in cultures of primary sensory neurones.

A method for enriching the fraction of nociceptive neurones in cultures of primary sensory neurones is described. Neurones from neonatal rat dorsal root ganglia were isolated, layered on 40% Ficoll and centrifuged, separating the neurones into a low density fraction (LDF) and a high-density fraction (HDF). The LDF had a smaller mean diameter (19.7 microm) than the HDF (27.3 microm) and uncentrifuged cells (23.6 microm). The proportion of cells immunoreactive for antibodies to substance P and calcitonin gene-related peptide, both of which are found in nociceptive neurones, was significantly greater in the LDF than in HDF. A substantial enrichment of the proportion of neurones responding to the algogenic substances capsaicin and bradykinin with an increase in intracellular calcium was observed in the LDF. The proportion of capsaicin and bradykinin-responsive neurones was also found to be increased by culturing the neurones, with a particularly pronounced enhancement in the proportion of bradykinin-responsive cells. We conclude that separation on the basis of density followed by culture is a useful way of enriching the proportion of nociceptive neurones for the purpose of electrophysiological, biochemical or other studies.

Animals↗
PubMed1997

Fibrinolysis changes in normal pregnancy.

The aim of this study was to evaluate the changes in fibrinolysis parameters during pregnancy. Normal pregnant women (n = 60) formed the study population. Blood samples were taken in the first, second and third trimester, during delivery and three days after delivery. Fibrinolysis parameters were estimated using commercial tests. Tissue plasminogen activator, D-dimer and plasminogen activator inhibitors (PAI-1 and PAI-2) were determined. Tissue plasminogen activator and D-dimer increased after the first trimester and reached maximum levels during delivery. Plasminogen activator inhibitors type 1 and type 2 were also higher, in particular PAI-2, and reached maximum levels in the third trimester. On the third day after delivery, fibrinolysis activity recovered, but D-dimer and PAI-2 levels remained above the normal non-pregnant range.

Adult↗
PubMed1997

[Effects of percutaneous intrahepatic portosystemic shunt on splanchnic and systemic hemodynamics in patients with portal hypertension].

Transjugular intrahepatic portosystemic shunt (TIPS) is a calibrated shunt directed at reducing the portal pressure gradient with a low incidence of hepatic encephalopathy and deterioration of hepatocellular function. The present study investigated the effects of TIPS on splanchnic and systemic hemodynamics on liver function and on the development of encephalopathy. A group of 30 patients treated with TIPS were included in the study: 26 patients with hepatic cirrhosis for an hemorrhagic episode by esophageal varices not controlled by medical treatment and sclerotherapy and in 4 cases with the Budd-Chiari syndrome for ascites refractory to medical treatment. Before, at 24 hours and 2 months after TIPS, the portal pressure gradient, cardiopulmonary pressure and cardiac output, blood flow of the azygos vein, and hepatic clearance of indocyanine green as indexes of liver function were determined. TIPS significantly decreased the portal pressures gradient and azygos blood flow. This was associated with a significant increase in cardiac output and a significant decrease in peripheral vascular resistance and hepatic clearance of indocyanine green. Portal flow deviated by TIPS was greater in the 9 patients (30%) who developed hepatic encephalopathy during follow up. In conclusion, TIPS effectively reduces portal hypertension. Nonetheless, it is associated with an increase in hyperdynamic circulation, a high incidence of encephalopathy and a deterioration in liver function.

Adolescent↗
PubMed1997

Effects of time of storage, albumin, and osmolality changes on outflow facility (C) of bovine anterior segment in vitro.

PURPOSE: To analyze the influence of time of storage, the presence of albumin at physiological concentrations, and the perfusion with anisosmotic media on the aqueous humor outflow facility (C) of isolated bovine anterior segments (AS). METHODS: Anterior segments dissected from cow eyes were perfused at a constant pressure of 10 mm Hg with Dulbecco's modified Eagle's medium (DMEM; osmolality 300 mOsm/kg), with hyposmotic media (150, 210, and 270 mOsm/kg), or with hyperosmotic media (360, 420, and 480 mOsm/kg). Outflow facility was calculated every 5 seconds as the ratio between average inflow from the reservoir (in microliters per minute) and the perfusion pressure (in millimeters of mercury). Three groups were studied: a 0-hour group, with AS perfused with DMEM 1 to 3 hours after enucleation; a 0-hour alb-group, with AS perfused with DMEM plus 0.1 mg/ml albumin 1 to 3 hours after enucleation; and a 24-hour group, with AS perfused after storage for 24 hours in DMEM. In the 0-hour groups, perfusion with increasingly hyposmotic or hyperosmotic media was also made in 30-minute steps, followed by a return to isosmotic medium for 90 minutes. RESULTS: Perfusion of AS with DMEM for 9 hours caused a progressive increase in C that was statistically significant at 225 minutes in the 0-hour group perfused with DMEM and at 195 minutes in the 24-hour group perfused with DMEM. The 0-hour alb-group perfused with DMEM did not show changes in C throughout the 9-hour perfusion period. Perfusion with increasingly hyposmotic media induced a progressive decrease in C that did not recover on return to isotonic medium. Hyperosmotic media caused a progressive increase in C that returned to control values when isotonic medium was again perfused. CONCLUSIONS: Preservation of tissue for C measurements is best achieved with short storage time (1 to 3 hours). Physiological concentrations of albumin (0.1 mg/ml) prevent development of washout, suggesting that albumin or an albumin-bound factor in aqueous humor may play a role in the maintenance of outflow resistance. Outflow facility also may be influenced by volume changes in the trabecular meshwork.

Animals↗
PubMed1995

[Carotid atherosclerosis evaluated by two-dimensional ultrasonography in patients with primary hypercholesterolemia].

BACKGROUND: Two-dimension ultrasonography permits to noninvasively quantify extracoronary atherosclerosis. The objective of this study was to assess preclinical atherosclerosis of the extracranial carotid arteries in patients with primary hypercholesterolemia. METHODS: Lipid and nonlipid cardiovascular risk factors were evaluated in 206 patients with dyslipidemia (127 men and 79 women, mean age 49 years, range 18-75), and a multifactorial cardiovascular risk profile was constructed for each patient. Ultrasound measurements of the intima-media thickness in the common carotid artery of each side were taken, and the number and height of any atheroma plaques present were quantified. RESULTS: Asymptomatic plaques were found in 120 patients (58%), and were more frequent in men than in women (65 vs 47%, p = 0.009), and in patients with than in those without prior coronary heart disease (80 vs 50%, p < 0.001). Both intimal thickening, indicative of early atherosclerosis, and the extent of arterial wall involvement with plaques, which represents an advanced stage of the disease, increased significantly with age and with increasing multifactorial cardiovascular risk, reflecting a positive relation between signs of atherosclerosis and the burden of risk factors. Intima-media thickness also increased with increasing plaque score, indicating the generalization of atherosclerosis. CONCLUSIONS: The high prevalence of preclinical carotid atherosclerosis confirms the atherogenic risk of primary dyslipidemias. The relation between carotid lesions and both coronary heart disease and multifactorial risk supports the validity of arterial ultrasound studies for cardiovascular risk prediction.

Adolescent↗
PubMed1994

Bone marrow purging in acute lymphoblastic leukemia: biological and clinical features.

A group of 56 patients with immunophenotyped acute lymphoblastic leukemia had their bone marrow purged using monoclonal antibody (MAb) and complement. Mononuclear marrow cells were treated with panels of MAb directed against T cells (n = 19), CD10-CALLA (n = 16), and B cells (n = 21), resulting in median specific cell depletions of 96.50, 97.59, and 96.97%, respectively. The resulting CFU-GM recoveries were 60.15, 110.6, and 72.9%. Long-term bone marrow cultures showed normal formation of adherent cell layers in 17 of 23 cases, and failure to form an adherent layer correlated with poor hematological reconstitution. A total of 32 patients (aged 4-40 years) received purged marrow grafts containing a median of 1.32 x 10(7) mononuclear cells/kg and 1.64 x 10(4) CFU-GM/kg; 7 patients required backup marrow. Time to engraftment of 500 granulocytes, 1000 leukocytes, 20,000 platelets, and 50,000 platelets was 37, 38, 39, and 57 days, respectively. A total of 16 patients (50%) remain alive and in complete remission 313-913 days posttransplant (median 565 days); 13 patients (41%) relapsed between 50 and 365 days posttransplant (median 100 days), and 3 patients (9%) died from transplant-associated complications.

Adolescent↗
PubMed1994

Cell function studies in long-term bone marrow culture after cell concentration and cryopreservation for autologous transplantation.

Autologous bone marrow transplantation (ABMT) is frequently used in the treatment of neoplastic diseases. It involves several manipulations in vitro that can damage the stem cells responsible for grafting. Long-term bone marrow cultures (LTBMC) reproduce the bone marrow microenvironment and support haematopoiesis in vitro for several weeks. This technique provides information on the extent of the injury of stem cells during manipulations of bone marrow cells in vitro. We studied the effect of the usual process of bone marrow cells in vitro in autologous transplantation: cell concentration and cell cryopreservation. 28 bone marrows from healthy donors and 45 from patients who had undergone ABMT were assayed in LTBMC. The cultures were initiated after manual or automatic buffy coat cell separation or after density gradient or automatic mononucleated cells suspension. Bone marrows were studied pre- and post-cryopreservation. The results show that several manipulations can disturb normal cell behaviour in LTBMC. Following automatic mononucleated cell separation and after thawing, the development of adherent cell layer in LTBMC is anomalous. These manipulations led to a delay in covering 50% of the flask surface, absence of adypocytes in adherent cell layer and absence of haemopoietic precursors in the supernatant at the 4th week of culture. The results suggest that LTBMC can be used for control of the manipulations in vitro related with ABMT.

Bone Marrow Cells↗