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J Weber

Publications and source records attributed to J Weber.

At least 19 recordsLinked to original sources
PubMed2006

Bayesian network analysis of resistance pathways against HIV-1 protease inhibitors.

Interpretation of Human Immunodeficiency Virus 1 (HIV-1) genotypic drug resistance is still a major challenge in the follow-up of antiviral therapy in infected patients. Because of the high degree of HIV-1 natural variation, complex interactions and stochastic behaviour of evolution, the role of resistance mutations is in many cases not well understood. Using Bayesian network learning of HIV-1 sequence data from diverse subtypes (A, B, C, F and G), we could determine the specific role of many resistance mutations against the protease inhibitors (PIs) nelfinavir (NFV), indinavir (IDV), and saquinavir (SQV). Such networks visualize relationships between treatment, selection of resistance mutations and presence of polymorphisms in a graphical way. The analysis identified 30N, 88S, and 90M for nelfinavir, 90M for saquinavir, and 82A/T and 46I/L for indinavir as most probable major resistance mutations. Moreover we found striking similarities for the role of many mutations against all of these drugs. For example, for all three inhibitors, we found that the novel mutation 89I was minor and associated with mutations at positions 90 and 71. Bayesian network learning provides an autonomous method to gain insight in the role of resistance mutations and the influence of HIV-1 natural variation. We successfully applied the method to three protease inhibitors. The analysis shows differences with current knowledge especially concerning resistance development in several non-B subtypes.

Bayes Theorem↗
PubMed2006

Use of sedation for routine diagnostic upper gastrointestinal endoscopy: a European Society of Gastrointestinal Endoscopy Survey of National Endoscopy Society Members.

BACKGROUND/AIMS: Sedation rates may vary among countries, depending on patients' and endoscopists' preferences. The aim of this survey was to investigate the rate of using premedication for routine diagnostic upper gastrointestinal (UGI) endoscopy in endoscopy societies, members of the European Society of Gastrointestinal Endoscopy (ESGE). METHODS: We evaluated a multiple-choice questionnaire which was e-mailed to representatives of national endoscopy societies, which are members of the ESGE. The questionnaire had 14 items referring to endoscopy practices in each country and the representatives' endoscopy units. RESULTS: The response rate was 76% (34/45). In 47% of the countries, less than 25% of patients undergo routine diagnostic UGI endoscopy with conscious sedation. In 62% of the responders' endoscopy units, patients are not asked their preference for sedation and do not sign a consent form (59%). Common sedatives in use are midazolam (82%), diazepam (38%) or propofol (47%). Monitoring equipment is not available 'in most of the endoscopy units' in 46% (13/28) of the countries. Though they were available in 91% of the national representatives' endoscopy units, they are rarely (21%) used to monitor unsedated routine diagnostic UGI endoscopy. CONCLUSIONS: In about 50% of ESGE-related countries, less than 25% of patients are sedated for routine diagnostic UGI endoscopy. Major issues to improve include availability of monitoring equipment and the use of a consent form.

Procedural Sedation↗
PubMed2006

Global and regional reproducibility of T2 relaxation time measurements in human patellar cartilage.

Seven T2 maps (multiecho (ME) sequence: 3000 ms, eight echoes with 13.2 ms of echo spacing, 20 sections) and T1-weighted (T1-w) fast low-angle shot (FLASH-water excitation (WE)) data sets from four imaging sessions (right patellae of 10 healthy volunteers) were obtained. A segmentation of cartilage (WE sequence) was overlaid on the ME data and T2 values were calculated for total cartilage, three layers, three facets (global), and 240 ROIs (regional). Reproducibility (precision error) was calculated as the root mean square average (RMSA) of the individual coefficients of variation (COVs, %) and standard deviations (SDs, ms) for intra- and intersession reproducibility. The precision error was 3-7% and 6-29% for global and regional T2, respectively. There was no difference between intra- and intersession reproducibility, but there was worse reproducibility in the superficial layers compared to the deeper layers. Peripheral ROI reproducibility (mean=13%) was worse than in the central portions (mean=11%), but omission of the periphery did not positively affect the globally calculated T2 reproducibility. The precision errors were small compared to reported changes in diseased cartilage, suggesting good discriminatory power of the technique. Our data provide a first estimate of global and regional reproducibility errors of T2 in healthy cartilage, and may serve as a basis for sample size calculations and aid study designs for longitudinal and cross-sectional trials in osteoarthritis (OA).

Adult↗
PubMed2006

[The undetected brain lesion in sports. Minor traumatic brain injury and its sequelae].

The minor traumatic brain injury (mTBI) in sports is often looked at as a bagatelle. The treating physician underestimates the severity of the injury suspecting that a mTBI is a nonstructural lesion with an overall excellent prognosis in the majority of the cases. This paper shows that the minor traumatic brain injury may be a structural brain lesion with potentially life-threatening dangers. The therapy should follow exactly defined guidelines, e.g., stepwise protocol of the Concussion in Sports (CIS-) Group. Return to sports activities should happen only when all physical but also cognitive symptoms have subsided. All mTBIs that have been sustained prior to the actual injury have to be recorded properly because repeated mTBIs may cause chronic degenerative brain damage. Neuropsychological testing will aid in the correct diagnosis of a mTBI and is a useful parameter in the course of the injury. In the future biochemical markers may serve as indicators of the severity of the brain injury and may also aid in predicting the outcome after TBI. Today biochemical markers do not serve as a substitute for neuroimaging.

Adolescent↗
PubMed2006

Congenital vascular malformations: the persistence of marginal and embryonal veins.

BACKGROUND: In about 18% of cases with conginental vascular malformations we find a perspective of an atypical truncular vein, located along the outside of the leg, frequently extended from the dorsal foot up to the bottom. In presence of a normally developed system of the deep collecting veins of the lower limb and within the pelvic outflow we are talking about a persisting marginal vein (MV). Hypoplasia or even aplasia of the main deep veins in contrary defines the persisting embryonal vein (EV). Already in childhood these truncular dysplastic veins tend to develop varicose enlargement, causing severe reflux of a huge volume of blood--even more when being associated with av-fistulas (46%). In consequence a rapidly growing chronic venous insufficiency will guide to additional injuries. PATIENTS AND RESULTS: We have analysed 97 patients showing a persisting MV (n: 92 ) within a total of 102 legs. A persistent embryonal vein (EV) was seen 10 times within this clientel. The persisting truncular veins, associated with phlebectasias and typical clinical symptoms have been examined in a diagnostic "step-by-step" procedure, mainly phlebographically (ascending leg phlebography and varicography), including direct venous blood pressure measurements (phlebodynamometry) and--if needed--by arteriography, showing av-shunting fistulae in 46% of cases. CT and MRI were consulted for the exact therapy planing (frequently initially offered as a non-invasive, however, inadequate key of diagnostic). Actually now these techniques cannot replace pre-operatively the angiographic imaging techniques. CONCLUSIONS: The analysis of clinical, morphologic and functional signs, guiding to a specific therapy-relevant classification of MV's and EV's will be presented. And a specific strategy of surgical repair, interventional treatment of av-fistulas and conservative compressive follow-up treatment attempting palliative recompensation of the diseased venous outflow will be discussed also.

Adolescent↗
PubMed2006

Kinematic analysis of the golf swing in men and women experienced golfers.

Golf has become an increasingly popular sport, which is enjoyed by both men and women. This paper addresses the question what differences may exist between men and women golfers. The purpose of this study is to analyze the kinematic pattern of the golf swing in both men and women experienced golfers. Seven male and five female golfers participated in the study. The measurements of kinematic data during swing were obtained with the optoelectronic system VICON (Oxford's Metric, Oxford, UK) with five cameras operating at 50 frames per second. Clubhead speed was measured using a radar system (Bell-Tronics, Ltd, Covington, USA). A Mann-Whitney test (p = 0.05) showed that the women seem to produce a wide swing with larger hip and shoulder joint rotation angles at the top of the backswing. Men flexed their left knee more during the backswing, this may promote a greater weight transfer to the right side. Nevertheless, these two kinematic patterns showed no significant differences in the clubhead speed. Men probably used their increased knee flexion to compensate for their muscular and articular suppleness which is less than that of the women. The results of this study show that there is a specific swing for women.

Adult↗
PubMed2006

Transmitted drug-resistant HIV-1 in primary HIV-1 infection; incidence, evolution and impact on response to antiretroviral therapy.

OBJECTIVES: The aim of the study was to determine the incidence and persistence of transmitted drug-resistant HIV-1 in an incident cohort between 2000 and 2004, and to investigate the impact of transmitted drug-resistant HIV-1 on the response to antiretroviral therapy (ART). METHODS: A prospective, nonrandomized study was carried out on 140 individuals identified with primary HIV-1 infection (PHI). PHI was defined as an HIV-positive antibody test with an HIV antibody-negative result in the prior 6 months (n = 69); positive HIV DNA in the absence of antibody (n = 30); an evolving titre positive HIV antibody test (n = 23), or an incident 'detuned' assay (B clade viruses only) (n = 18). Genotypic resistance testing was performed at baseline, following ART and annually over a 4-year period. RESULTS: The prevalence of transmitted drug-resistant HIV-1 infection between January 2000 and June 2004 was nine in 140 (6.0%) and the annual incidence was stable. Seven of these nine patients had a single point mutation conferring single-class drug resistance and the other two patients had multiple mutations conferring multiclass drug resistance (MDR). In eight of the nine cases, mutations conferring drug resistance persisted for more than 12 months off therapy. In contrast to transmitted MDR HIV-1, the virological response to initial ART and CD4 decline were comparable in those with wild-type virus, virus with 'polymorphisms' (secondary mutations) and virus with single drug-resistance mutations. CONCLUSIONS: The incidence of transmitted drug-resistant HIV remained stable and low over a 4-year period. Although MDR remains rare, its presence significantly affects the response to first-line ART, predisposes towards the accumulation of new resistance mutations and is associated with a more rapid CD4 decline.

Adult↗
PubMed2006

Passive sexual transmission of human immunodeficiency virus type 1 variants and adaptation in new hosts.

Human immunodeficiency virus type 1 (HIV-1) genetic diversity is a major obstacle for the design of a successful vaccine. Certain viral polymorphisms encode human leukocyte antigen (HLA)-associated immune escape, potentially overcoming limited vaccine protection. Although transmission of immune escape variants has been reported, the overall extent to which this phenomenon occurs in populations and the degree to which it contributes to HIV-1 viral evolution are unknown. Selection on the HIV-1 env gene at transmission favors neutralization-sensitive variants, but it is not known to what degree selection acts on the internal HIV-1 proteins to restrict or enhance the transmission of immune escape variants. Studies have suggested that HLA class I may determine susceptibility to HIV-1 infection, but a definitive role for HLA at transmission remains unproven. Comparing populations of acute seroconverters and chronically infected patients, we found no evidence of selection acting to restrict transmission of HIV-1 variants. We found that statistical associations previously reported in chronic infection between viral polymorphisms and HLA class I alleles are not present in acute infection, suggesting that the majority of viral polymorphisms in these patients are the result of transmission rather than de novo adaptation. Using four episodes of HIV-1 transmission in which the donors and recipients were both sampled very close to the time of infection we found that, despite a transmission bottleneck, genetic variants of HIV-1 infection are transmitted in a frequency-dependent manner. As HIV-1 infections are seeded by unique donor-adapted viral variants, each episode is a highly individual antigenic challenge. Host-specific, idiosyncratic HIV-1 antigenic diversity will seriously tax the efficacy of immunization based on consensus sequences.

AIDS Vaccines↗
PubMed2006

Primary HIV.

Explore the source record for details and available documents.

Antiretroviral Therapy, Highly Active↗
PubMed2006

Prevention of major venous thromboembolism following total hip or knee replacement: a randomized comparison of low-molecular-weight heparin with unfractionated heparin (ECHOS Trial).

AIM: Venous thromboembolism remains a frequent complication after total hip or knee replacement surgery despite routine prophylaxis. However, the ability of pharmacologic thromboprophylaxis to prevent major venous thromboembolism, defined as proximal deep vein thrombosis, and/or pulmonary embolism, and/or death, has not been previously validated. METHODS: In a double-blind randomized study, 2018 patients, undergoing either total hip or knee replacement surgery, were allocated to receive subcutaneous preoperative reviparin (4,200 anti Xa IU) once daily or 7,500 IU unfractionated heparin twice daily, for a minimum of 11 days. The primary efficacy outcome was major venous thromboembolism, defined as the composite of venographically confirmed proximal deep vein thrombosis, and/or symptomatic pulmonary embolism and death, recorded up to day 14. RESULTS: The primary efficacy outcome was assessed in 1,628 patients and demonstrated a significant reduction in the reviparin group (3.4% [28 of 813 patients] compared with unfractionated heparin (5.5% [45 of 815]) (odds ratio, 0.61; 95% confidence interval, 0.38 to 0.99, P=0.04) by day 11 to 14. A significant reduction in venous thromboembolism was maintained up to 6-8 weeks (3.4% [28 of 813 reviparin patients] versus 5.6% [46 of 815 unfractionated heparin patients]) (odds ratio, 0.6; 95% confidence interval, 0.37 to 0.97, P=0.03). Major bleeding events occurred in 9 reviparin-treated patients (0.9%) and in 12 unfractionated heparin-treated patients (1.2%). CONCLUSIONS: Prophylaxis with reviparin significantly reduces the risk of major venous thromboembolism compared with unfractionated heparin in patients undergoing elective hip or knee replacement without increasing the risk of bleeding.

Adult↗
PubMed2005

Levels of polychlorinated biphenyls (PCBs) in meat and meat products from the state of Rio Grande do Sul, Brazil.

The levels of six polychlorinated biphenyl congeners (PCBs) were evaluated in 55 samples of meat (bovine and pork) and meat products (sausage, hot dog sausage, bologna sausage, canned export meat and salami) from 11 cities of the state of Rio Grande do Sul, Brazil, between July and August 2002. PCB congeners were found (in fat basis) in the following rank 52 (5.18 ng/g) > 180 (1.69 ng/g) > 10 (1.35 ng/g) > 28 (1.19 ng/g) >153 (0.47 ng/g) >138 (0.43 ng/g), with a summation SigmaPCB amounting to 10.30 ng/g. Meat products had higher PCB levels than meat. PCB levels in samples followed the rank: mixed meat products > pork meat > bovine meat. These results indicate the presence of PCBs in food samples from Rio Grande do Sul, Brazil, but the levels found were well below the maximum level established for animal food products in Brazil (3000 ng/g fat). Only one sample exceeded the maximum level established by the European Community (200 ng/g fat). This is the first paper describing background concentrations of PCBs in meat and meat products from Brazil.

Animals↗
PubMed2005

Trends in work-related musculoskeletal disorder reports by year, type, and industrial sector: a capture-recapture analysis.

BACKGROUND: Musculoskeletal disorders (MSD) are thought to be declining based on Bureau of Labor Statistics survey data, but there is also evidence of MSD under-reporting, raising the possibility of contrary trends. The magnitude of MSD under-reporting over time, and its industry distribution have not been adequately described. METHODS: Capture-recapture analysis of 7 years of Connecticut MSD (1995-2001), utilizing Workers' Compensation and physician reporting data was performed. RESULTS: Only 5.5%-7.9% of MSD cases appear to be reported to Workers Compensation annually. The capture-recapture estimated average annual rate for upper-extremity MSD was 133.1 per 10,000 employed persons, far above BLS rates. By industry, Manufacturing, State Government, and the Finance/Insurance/Real Estate sectors all had significantly higher MSD rates than Wholesale/Retail Trade. CONCLUSIONS: Upper-extremity MSD appears to be significantly under-reported, and rates are not decreasing over time. Capture-recapture methods provide an improved surveillance method for monitoring temporal trends in injury rates.

Adult↗
PubMed2005

High-resolution diffusion tensor imaging of human patellar cartilage: feasibility and preliminary findings.

MR diffusion tensor imaging (DTI) was used to analyze the microstructural properties of articular cartilage. Human patellar cartilage-on-bone samples were imaged at 9.4T using a diffusion-weighted SE sequence (12 gradient directions, resolution = 39 x 78 x 1500 microm(3)). Voxel-based maps of the mean diffusivity, fractional anisotropy (FA), and eigenvectors were calculated. The mean diffusivity decreased from the surface (1.45 x 10(-3) mm(2)/s) to the tide mark (0.68 x 10(-3) mm(2)/s). The FA was low (0.04-0.28) and had local maxima near the surface and in the portion of the cartilage corresponding to the radial layer. The eigenvector corresponding to the largest eigenvalue showed a distinct zonal pattern, being oriented tangentially and radially in the upper and lower portions of the cartilage, respectively. The findings correspond to current scanning electron microscopy (SEM) data on the zonal architecture of cartilage. The eigenvector maps appear to reflect the alignment of the collagenous fibers in cartilage. In view of current efforts to develop and evaluate structure-modifying therapeutic approaches in osteoarthritis (OA), DTI may offer a tool to assess the structural properties of cartilage.

Anisotropy↗
PubMed2005

[Postural biofeedback and locomotion reeducation in stroke patients].

AIMS: To compare, in post-acute hemiparetic patients, gait improvement after conventional physical therapy alone or with a specialised balance retraining program. PATIENTS: Twenty-six patients within 3 months of onset of stroke were randomised to receive physical therapy (control group) or therapy and retraining (experimental group), most of the patients in both groups with left hemiplegia. The experimental group was significantly older than the control group. METHOD: Thirteen patients received early conventional therapy, and 13 received therapy combined with standing balance training by biofeedback (BPM Monitor). Clinical measures were collected at entry (J0), once when subjects began to walk (JM) and 30 days later (JM + 30). Gait spatiotemporal parameters were collected by use of the Vicon system at JM and JM + 30. RESULTS: Whatever the method of rehabilitation, the clinical scores improved significantly between J0 and JM + 30, except for spasticity. The time between stroke and the beginning of walking was not significantly different between both groups. Gait velocity increased significantly between JM and JM + 30 in both groups, with no difference between groups. The walking pattern was improved for both groups, with a significant increase of the duration of the paretic limb single stance. The experimental group significantly improved the duration of the reception double stance on the paretic limb between JM and JM + 30 compared with the control group (P = 0.03). CONCLUSION: Both groups demonstrated improvement in the rehabilitation unit. The benefits of visual biofeedback by forceplate system training suggest particular improvement of anticipation equilibrium with conventional therapy.

Aged↗
PubMed2005

Comparison of intra-arterial thrombolysis with conventional treatment in patients with acute central retinal artery occlusion.

BACKGROUND: Several case series and a recent meta-analysis indicate that intra-arterial thrombolysis (IAT) is effective for the treatment of acute central retinal artery occlusion (CRAO). METHODS: A total of 37 patients with acute monocular blindness because of unilateral thromboembolic CRAO were treated with IAT using urokinase within six hours of the onset of symptoms. Visual outcome was compared with a control group of 19 patients, also seen within six hours, who did not undergo thrombolytic treatment. In both groups some patients were treated by paracentesis and/or acetazolamide. Predictors of visual outcome were evaluated. RESULTS: Visual improvement was more likely with IAT (p = 0.01) as were the chances to regain visual acuity of >0.6 significantly better (p = 0.04): 8/37 patients (22%) regained visual acuity of >0.6 in the IAT group and none (0/19) in the control group. Younger patients were more likely to regain some vision with (p = 0.012) or without IAT (p = 0.026). Three patients had minor treatment related cerebral ischaemic events, two had transient ischaemic attacks and one a minor stroke. There were no haemorrhagic complications. CONCLUSIONS: This series of patients with CRAO demonstrated that IAT enhanced the chances of visual improvement compared with conventional treatment only. Furthermore, younger patients have a better chance to achieve some visual recovery.

Acute Disease↗