Outcome of Patients with Venous Thromboembolism and Factor V Leiden or Prothrombin 20210 Carrier Mutations During the Course of Anticoagulation

BACKGROUND

Individuals with factor V Leiden or prothrombin G20210A mutations are at a higher risk to develop venous thromboembolism. However, the influence of these polymorphisms on patient outcome during anticoagulant therapy has not been consistently explored.

METHODS

We used the Registro Informatizado de Enfermedad TromboEmbólica database to compare rates of venous thromboembolism recurrence and bleeding events occurring during the anticoagulation course in factor V Leiden carriers, prothrombin mutation carriers, and noncarriers.

RESULTS

Between March 2001 and December 2015, 10,139 patients underwent thrombophilia testing. Of these, 1384 were factor V Leiden carriers, 1115 were prothrombin mutation carriers, and 7640 were noncarriers. During the anticoagulation course, 160 patients developed recurrent deep vein thrombosis and 94 patients developed pulmonary embolism (16 died); 154 patients had major bleeding (10 died), and 291 patients had nonmajor bleeding. On multivariable analysis, factor V Leiden carriers had a similar rate of venous thromboembolism recurrence (adjusted hazard ratio [HR], 1.16; 95% confidence interval [CI], 0.82-1.64), half the rate of major bleeding (adjusted HR, 0.50; 95% CI, 0.25-0.99) and a nonsignificantly lower rate of nonmajor bleeding (adjusted HR, 0.66; 95% CI, 0.43-1.01) than noncarriers. Prothrombin mutation carriers and noncarriers had a comparable rate of venous thromboembolism recurrence (adjusted HR, 1.00; 95% CI, 0.68-1.48), major bleeding (adjusted HR, 0.75; 95% CI, 0.42-1.34), and nonmajor bleeding events (adjusted HR, 1.10; 95% CI, 0.77-1.57).

CONCLUSIONS

During the anticoagulation course, factor V Leiden carriers had a similar risk for venous thromboembolism recurrence and half the risk for major bleeding compared with noncarriers. This finding may contribute to decision-making regarding anticoagulation duration in selected factor V Leiden carriers with venous thromboembolism.

Ursodeoxycholic acid reduces lipid peroxidation and mucin secretagogue activity in gallbladder bile of patients with cholesterol gallstones

BACKGROUND

Recently it has been postulated that gallbladder mucin hypersecretion observed in the pathogenesis of cholesterol gallstone disease may be induced by biliary lipid peroxidation. Ursodeoxycholic acid treatment reduces mucin concentration and the formation of cholesterol crystals in the gallbladder bile of patients with cholesterol gallstones and this effect might be mediated by a decrease of biliary lipid peroxidation.

MATERIAL AND METHODS

In a double-blind, placebo-controlled trial patients with symptomatic cholesterol gallstones received either ursodeoxycholic acid (750 mg daily) (n = 10) or placebo (n = 12) 10-12 days prior to cholecystectomy. As a marker for lipid peroxidation malondialdehyde was measured in bile together with mucin concentration. In addition, the mucin secretagogue activity of the individual bile samples was assessed in cultured dog gallbladder epithelial cells.

RESULTS

Ursodeoxycholic acid therapy resulted in a significant reduction of lipid peroxidation in bile as determined by the biliary malondialdehyde concentration (1.36 +/- 0.28 vs. 2.05 +/- 0.38 micromol L(-1); P < 0.005) and the malondialdehyde (micromol L(-1))/total bile acid (mmol L(-1)) ratio (0.02 +/- 0.005 vs. 0.06 +/- 0.01; P < 0.001). Furthermore, a decrease in mucin concentrations (0.7 +/- 0.3 vs. 1.3 +/- 0.5 mg mL(-1); P < 0.005) and of the mucin secretagogue activity of gallbladder bile (0.9 +/- 0.2 vs. 2.2 +/- 0.3 times control; P < 0.001) was observed.

CONCLUSIONS

The reduction of lipid peroxidation and mucin secretagogue activity of gallbladder bile induced by ursodeoxycholic acid treatment may contribute to the beneficial effects of this drug on gallbladder bile composition and symptoms in cholesterol gallstone patients.

Three-dimensional finite element analysis of human temporomandibular joint with and without disc displacement during jaw opening

The aim of this study was to evaluate the differences of stress distribution in the temporomandibular joint (TMJ) disc during jaw opening between the subjects with and without internal derangement of TMJ (TMJ-ID). Three symptom-free volunteers and three symptomatic patients with anterior disc displacement were selected as normal and TMJ-ID subjects, respectively. For each subject, magnetic resonance images (MRI) were taken in the axial, sagittal and coronal directions. Using MRI taken, six three-dimensional finite element models of TMJ were developed. For each subject, the condylar movements during jaw opening were recorded and used as the loading condition for stress analysis. By comparing the calculated disc displacement to the measured one from MRI, the frictional coefficients were mu = 0.001 for the normal subjects, but mu = 0.01-0.001 for the TMJ-ID subjects. For the normal subjects, relatively high stresses were found at the anterior and lateral portions of the disc throughout jaw opening. In the connective tissues, the stress level was higher in the TMJ-ID than in the normal subjects. It is suggested that the disc displacement induces the change of stress distribution in the disc and the increase of frictional coefficients between articular surfaces, resulting in the secondary tissue damage.

The regional difference of viscoelastic property of bovine temporomandibular joint disc in compressive stress-relaxation

An in vitro experimental technique was performed to measure the viscoelastic properties of the bovine disc. Thirteen TMJ discs from young cattle (3-year-old) were used. Each disc was divided into five specimens of anterior, central, posterior, lateral and medial regions, and they were used for compression tests. A series of stress-relaxation tests was conducted for each specimen from 5% strain up to 20% strain with 5% intervals. The stress-relaxation was monitored over a period of 5 min. Each region exhibited a different biomechanical behavior, which is presumably related to the organization and distribution of proteoglycans that indirectly modulate the stiffness of the collagen network. It is suggested that an improved understanding of the viscoelastic properties of the disc under function may guide consideration for design and selection of biomaterials for TMJ reconstruction.

Start-up of a pilot-scale anaerobic fixed film reactor at low temperature treating slaughterhouse wastewater

A pilot-scale anaerobic fixed film reactor (AFFR) with vertically arranged PVC tubes as biomass carrier, treating poultry slaughterhouse wastewater was started-up in 74 days at temperatures between 20-24 degrees C. The start-up process consisted of a long acclimatization phase followed by a low loaded growth phase, a gradual increase of OLR upto 9.2 kg COD/m3d, and a final maturation phase at moderated loads of 2.7 kg COD/m3d at which total COD removal efficiencies of 57% were achieved. Alkalinity ratio IA:PA was found to be the best control parameter to avoid VFA accumulation. OLR increase based on pH control was not satisfactory because changes in CO2 solubility caused daily by temperature and flow variations led to pH oscillations of 0.2 units. The low wastewater alkalinity, 260 mg/l CaCO3 was insufficient to buffer the pH system, therefore the pH decrease associated with the VFA accumulation was not easily detected and could not be used as a way of OLR control. Organic matter removal took place by accumulation and biodegradation processes. Limitation in the reactor hydrodynamics and particulate fraction hydrolysis was detected at high flow rates.

Mucin and phospholipids determine viscosity of gallbladder bile in patients with gallstones

AIM: An increased viscosity of gallbladder bile has been considered an important factor in the pathogenesis of gallstone disease. Besides lipids and proteins, mucin has been suggested to affect the viscosity of bile. To further clarify these issues we compared mucin, protein and the lipid componEnts of hepatic and gallbladder bile and its viscosity in patients with gallstones.

METHODS: Viscosity of bile (mPa.s) was measured using rotation viscosimetry in regard to the non Newtonian property of bile at low shear rates.

RESULTS: Biliary viscosity was markedly higher in gallbladder bile of patients with cholesterol (5.00 ± 0.60 mPa.s, mean ± SEM, n = 28) and mixed stones (3.50 ± 0.68 mPa.s; n = 8) compared to hepatic bile (0.92 ± 0.06 mPa.s, n = 6). A positive correlation between mucin and viscosity was found in gallbladder biles (r = 0. 65; P < 0.001) but not in hepatic biles. The addition of physiologic and supraphysiologic amounts of mucin to gallbladder bile resulted in a dose dependent non linear increase of its viscosity. A positive correlation was determined between phospholipid concentration and viscosity (r = 0.34, P < 0.005) in gallbladder biles. However, no correlation was found between total protein or the other lipid concentrations and viscosity in both gallbladder and hepatic biles.

CONCLUSION: The viscosity of gallbladder bile is markedly higher than that of hepatic bile in patients with gallstones. The concentration of mucin is the major determinant of biliary viscosity and may contribute by this mechanism to the role of mucin in the pathogenesis of gallstones.

Effects of tensile forces on the expression of type III collagen in rat interparietal suture

The aim was to investigate the direct contribution of mechanically induced stress to synthesized type III collagen in the interparietal suture. Twenty 4-week-old male rats were used as experimental animals. An activated expansion spring was placed across the interparietal suture. After expansion, the parietal bones including the suture were dissected and immunostained for type I and III collagens. Also, a three-dimensional model of the interparietal suture was developed to analyze stress during expansion. The localization of type III collagen in the suture was dependent upon the duration of expansion. Although the control suture exhibited no or little reactivity for type III collagen, it was observed as early as 15 h of expansion in the cambial layers, and was distributed throughout the suture at 50 h of expansion. The time-dependent distribution of type III collagen was fully consistent with that of tensile stresses calculated by the use of a three-dimensional finite-element model. It was concluded that the increases in tensile stress are associated with the synthesis of type III collagen in the suture.

Changes in the biomechanical properties of the rat interparietal suture incident to continuous tensile force application

This study was designed to investigate the relation between the biomechanical behaviour of rat interparietal sutures and expansion forces placed on them. Thirty-five 4-week-old rats were divided into four groups, a control group and three experimental groups subjected to mechanical expansion of the interparietal sutures with a tensile force for 15, 30 and 50 h. After expansion, the parietal bones, including the interparietal suture, were dissected as specimens for tensile tests. Under tension, the relaxed stress-strain plots in the control group could be better fitted by a power of 2.00, and the relaxed moduli were 0.64 and 4.51 MPa at the lower and the higher applied strains, respectively. An initial fall in the relaxed moduli at 15 h of expansion was followed by an increase over time. It is therefore suggested that the biomechanical behaviour of the interparietal sutures is influenced by the duration of an external force.

Rapid formation of cholesterol crystals in gallbladder bile is associated with stone recurrence after laparoscopic cholecystotomy

Laparoscopic cholecystotomy (LCT) with subsequent extraction of gallstones and primary closure of the gallbladder has been introduced as an alternative therapy for patients with cholecystolithiasis and preserved gallbladder function. However, stone recurrence has to be considered as a major drawback that might be related to lithogenic factors of gallbladder bile or the composition of gallbladder stones. Therefore, these were studied in relation to stone recurrence within an observation period of 1 to 5 years (median, 3.6 years) in 50 patients after LCT. The concentrations of total and individual bile acids, phospholipids, cholesterol, total lipids, mucin, protein, and the cholesterol saturation indices in gallbladder bile were not significantly different between 10 patients with and 40 patients without stone recurrence. However, the crystal observation time was significantly (P < .02) shorter (range, 1-2 days; median, 1.5) in the bile of patients with stone recurrence compared to those without (range, 1-21 days, median 3.5). Moreover, all 10 stone recurrences were observed in the 28 patients with a crystal observation time in the bile of less than or equal to 2 days (approximate annual risk: 12%-15%), and no recurrences were observed in the 22 patients with a crystal observation time greater than 2 days (P < .0001) or in patients with pigment stones. The rapid formation of cholesterol monohydrate crystals in bile seems to be the major risk factor for recurrent stones after LCT. These are most likely cholesterol stones and, therefore, are amenable to oral bile-acid prevention or treatment.

Quantification of mucin in human gallbladder bile: a fast, specific, and reproducible method

It is generally accepted that gallbladder mucin (GBM) plays an important role in the pathogenesis of cholesterol gallstone (ChG) disease. However, it remains unclear whether ChG patients have higher GBM concentrations than controls. Discrepant findings regarding biliary mucin concentrations may be due to methodological problems with the assays commonly used. The methods currently used to quantitate mucin in bile have not been systematically evaluated. To establish a reliable method for mucin quantification in bile, we evaluated three mucin assays: the classic Pearson-PAS (periodic acid Schiff) assay, a direct fluorometric assay, and a new PAS or fluorometric assay with the following modifications of the Pearson assay: preincubation of bile samples with TBS containing KSCN and sodium taurocholate and micellation of biliary lipids during gel chromatographic fractionation using 25 mM sodium taurocholate in the elution buffer. SDS-PAGE and monoclonal anti-human-GBM (GBM59) were used to identify mucin. Highly specific and reproducible mucin isolation was achieved with the modified method. We found considerable loss of mucin during the different purification steps in the Pearson method. The direct fluorometric assay showed unspecific fluorometric signal with low molecular constituents of bile. Our experiments showed that human-GBM can be accurately measured after a simple modified chromatographic fractionation followed by a PAS or fluorometric assay.

Indomethacin decreases viscosity of gallbladder bile in patients with cholesterol gallstone disease

There is experimental evidence that inhibition of cyclooxygenase with nonsteroidal anti-inflammatory drugs may decrease cholesterol gallstone formation and mitigate biliary pain in gallstone patients. The mechanisms by which NSAIDs exert these effect are unclear. In a prospective, controlled clinical trial we examined the effects of oral indomethacin on the composition of human gallbladder bile. The study included 28 patients with symptomatic cholesterol or mixed gallstones. Of these, 8 were treated with 3 x 25 mg indomethacin daily for 7 days prior to elective cholecystectomy while 20 received no treatment and served as controls. Bile and tissue samples from the gallbladder were obtained during cholecystectomy. Indomethacin tissue levels in the gallbladder mucosa, as assessed by HPLC, were 1.05 +/- 0.4 ng/mg wet weight, a concentration known to inhibit effectively cyclooxygenase activity. Nevertheless, no differences between the treated and untreated groups were found in the concentrations of biliary mucus glycoprotein (0.94 +/- 0.27 versus 0.93 +/- 0.32 mg/ml) or total protein (5.8 +/- 0.9 versus 6.4 +/- 1.3 mg/ml), cholesterol saturation (1.3 +/- 0.2 versus 1.5 +/- 0.2), or nucleation time (2.0 +/- 3.0 versus 1.5 +/- 2.0 days). However, biliary viscosity, measured using a low-shear rotation viscosimeter, was significantly lower in patients receiving indomethacin treatment (2.9 +/- 0.6 versus 5.6 +/- 1.2 mPa.s; P < 0.02). In conclusion, in man oral indomethacin decreases bile viscosity without alteration of bile lithogenicity or biliary mucus glycoprotein content.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile acids inhibit secretion of very low density lipoprotein by rat hepatocytes

The influence of taurocholate on very low density lipoprotein (VLDL) triacylglycerol synthesis and secretion was studied by isolated rat liver-parenchymal cells. The incorporation of [3H]glycerol into cell-associated and VLDL triacylglycerols were measured after incubation in medium containing 0.75 mM oleate. Taurocholate caused a maked decrease in VLDL [3H]triacylglycerol secretion from the hepatocytes: 50-150 microM taurocholate inhibited secretion of VLDL [3H]triacylglycerols by 70-90%. Similar results were obtained when the mass of secreted VLDL triacylglycerols was measured. Taurocholate caused a decreased secretion of VLDL [3H]triacylglycerols after 15-30 min incubation. A higher amount of cellular triacylglycerols was found in taurocholate-supplemented cells. Furthermore taurocholate did not change the intracellular lipolysis of triacylglycerols. These results suggest that bile acids interfere more probably with the assembly and/or secretion of VLDL-particles and not with earlier stages of VLDL formation, e.g. triacylglycerol synthesis.