Search PubMed⌕ Search

Biomedical subjects

C Meyer

Publications and source records attributed to C Meyer.

At least 19 recordsLinked to original sources
PubMed2007

[Intraoperative radiation exposure in elastic stable intramedullary nailing (ESIN) during the growth period. Observations in 162 long bone shaft fractures].

BACKGROUND: The increase of intraoperative radiation exposure in intramedullary techniques of osteosynthesis is recognised and accepted in adults especially in interlocked nailing. In contrast data about fluoroscopy times in elastic stable intramedullary nailing (ESIN) in children and adolescents are hardly available. MATERIAL AND METHOD: Operation records of 162 surgical procedures (8.6% humerus, 43.8% forearm, 32.7% femur, 14.8% lower leg) of a 3-year period were evaluated retrospectively. The mean age was 6.1 years in femoral shaft fractures, nearly similar in forearm and lower leg fractures (8.7 and 7.9 years, respectively) and 12.4 years in patients with humeral shaft fractures. RESULTS: Mean operation (OP) and fluoroscopy times (FL) were increased in humeral fractures (58.1 min OP, 1.62 min FL), at a medium level in forearm fractures (35.2 min OP, 1.06 min FL) and femoral fractures (42.3 min OP, 1.27 min FL) and shortest in lower leg fractures (29.6 min OP, 0.69 min FL). CONCLUSION: Our results and literature analysis show that optimal technical conditions, especially the use of a pulsed image intensifier and well-trained theatre staff, are able to reduce intraoperative radiation load.

Body Burden↗
PubMed2007

Alcohol screening in general practices using the AUDIT: how many response categories are necessary?

AIMS: The Alcohol Use Disorders Identification Test (AUDIT) is a common screening instrument. This study analyses if response categories of the AUDIT might be dichotomized without affecting the psychometric properties of the questionnaire. METHODS: Participants between 18 and 65 years were recruited from general practices in two northern German cities. In total, 10,803 screenings were conducted (refusal rate: 5.9%). For those who were screened positive, the Munich-Composite International Diagnostic Interview (M-CIDI) was used for identification of 12-month Alcohol Use Disorders and at-risk consumption (exceeding 20/30 g per day). Abstinent subjects and screening positives without diagnostic interview were excluded from the analysis, leaving a sample of 7,112 subjects. ROC-Curves were calculated separately for each item in order to identify an optimal cut-off value. Finally, a version of the AUDIT based on dichotomized items was compared to the original version and its short-form, the AUDIT version based on three questions dealing with consumption AUDIT-C. RESULTS: As an optimal cut-off value for items on consumption, drinking at least once a week, having more than 1-2 drinks per occasion, and drinking 6 or more drinks in one sitting at least once a month were identified. For all questions on alcohol-related problems or dependence symptoms, having 'ever occurred' differed best between subjects with and without Alcohol Use Disorders or at-risk consumption. Sensitivity and specificity of the dichotomized version of the AUDIT did not differ from the original version, and both full versions performed superior compared to the AUDIT-C. CONCLUSION: Data indicate that the AUDIT response categories may be dichotomized without affecting its validity.

Adolescent↗
PubMed2006

[Recurrence of hepatitis C virus (HCV) infection after liver transplantation for HCV-related disease: host factors and viral factors implicated in the occurrence and the severity of HCV recurrence].

Cirrhosis due to chronic infection by hepatitis C virus (HCV), associated or not to a primary hepatocarcinoma, has become the first indication of liver transplantation. Graft reinfection by HCV is considered to be systematic while its prognosis is variable from one patient to another. A better knowledge of factors implicated in the occurrence and severity of hepatitis C recurrence is crucial in order to make optimal patients' monitoring. This article aims to present available data in this field, clarifying the role of viral factors (viral load, genotype, evolution of viral quasispecies) and host-related factors (immune response) which could take part in the development of hepatitis C recurrence.

Carcinoma, Hepatocellular↗
PubMed2006

CD95 ligand mediates T-cell receptor-induced apoptosis of a CD4+ CD8+ double positive thymic lymphoma.

Tumors in the thymus can be of different cellular origin. Among the most common tumors are thymoma and lymphoma, which are derived from transformed thymic epithelial cells and transformed lymphocytes, respectively. Thymic lymphoma and their response to apoptotic stimuli are poorly characterized. Here, we analyse apoptosis events in the thymic lymphoma cell line Thy278, which expresses cell surface antigens characteristic of immature double positive thymocytes. Upon T-cell receptor (TCR)/CD3 stimulation, Thy278 cells die by apoptosis, similar as primary thymocytes during negative selection. Caspases are crucial for deletion of both Thy278 cells and normal thymocytes. Moreover, we show that deletion of primary thymocytes and Thy278 cells upon CD3 stimulation is considerably impaired by neutralizing CD95L antibody. Thus, our results not only demonstrate that TCR-induced apoptosis is still functional in transformed thymocytes, but also suggest that Thy278 cells are a helpful model for the molecular analysis of negative selection.

Animals↗
PubMed2006

Cardiac stress MR imaging with dobutamine.

Stress testing for detection of ischemia-induced wall-motion abnormalities has become a mainstay for noninvasive diagnosis and risk stratification of patients with suspected coronary artery disease (CAD). Recent technical developments in magnetic resonance imaging (MRI), including the adoption of balanced steady-state free precession (b-SSFP) sequences-preferentially in combination with parallel imaging techniques-have led to a significant reduction of imaging time and improved patient safety. The stress protocol includes application of high-dose dobutamine (up to 40 microg/kg/min) combined with fractionated atropine (up to a maximal dose of 1.0 mg). High-dose dobutamine stress MRI revealed good sensitivity (83-96%) and specificity (80-100%) for detection of significant CAD. Myocardial tagging methods have been shown to further increase sensitivity for CAD detection. Severe complications (sustained tachycardia, ventricular fibrillation, myocardial infarction, cardiogenic shock) are rare but may be expected in 0.1-0.3% of patients. Dobutamine stress MRI has emerged as a reliable and safe clinical alternative for noninvasive assessment of CAD. New pulse sequences, such as real-time imaging, might obviate the need for breath holding and electrocardiogram (ECG) triggering in patients with severe dyspnoea and cardiac arrhythmias, which may further improve the clinical impact and acceptance of stress MRI in the future.

Atropine↗
PubMed2006

Smoking status, obesity and hypertension in a general population sample: a cross-sectional study.

BACKGROUND: In some studies, hypertension is more common in never and former smokers than in current smokers. AIM: To examine the associations between hypertension and smoking status, when divided into subgroups by overweight and obesity. DESIGN: Cross-sectional study. METHODS: We used data from a national health survey with a probability sample of the national population of Germany aged 18 to 79 (n = 6903 with complete data). Smoking status data were collected via questionnaire. Obesity and overweight were assessed by body mass index, hypertension by blood pressure measurement and by participants' statements about antihypertensive treatment. Analyses were adjusted for gender, age, history of coronary artery disease, serum cholesterol levels, alcohol drinking, exercise, and education. RESULTS: Obese former smokers who were abstinent for 3 or more years had an adjusted odds ratio (OR) 3.6 (95% confidence interval, CI 2.3-5.7) for mild hypertension (> or =140 mmHg systolic or > or =90 mmHg diastolic blood pressure) and an adjusted OR 6.5 (95%CI 3.6-11.8) for moderate or severe hypertension (> or =160 mmHg systolic or > or =100 mmHg diastolic). Normal weight never or former smokers did not differ from normal weight current smokers smoking > or =15 cigarettes/day with regard to likelihood of hypertension (normal weight never smokers, OR 1.1, 95%CI 0.8-1.5; normal weight former smokers, abstinent 3 or more years, OR 0.8, 95%CI 0.5-1.3). DISCUSSION: In this nationally representative sample, never or former smoking was unrelated to hypertension among normal weight individuals.

Adolescent↗
PubMed2006

[Left colon necrosis after endoscopic para-aortic lymph node exploration in a cervical carcinoma stage IIB].

Authors report a left colon ischemia six days after laparoscopic para-aortic lymphadenectomy in the staging of advanced cervical carcinoma. Before surgery, positron emission tomography scanning was performed: there were no para-aortic nodal metastasis. The histologic examination confirmed the radiological staging. Positron emission tomography scanning could avoid surgery in the case of patients with high risks morbidity factors.

Aged↗
PubMed2006

Clinical rotation in pathology: description of a case based approach.

BACKGROUND: The implementation of a system based, integrated curriculum at the Faculty of Health Sciences of Stellenbosch University, Western Cape, South Africa, resulted in less contact time for the pathology disciplines during theoretical modules, while a weekly rotation in pathology was introduced during clinical training in the fourth and fifth years. OBJECTIVE: To describe a problem based approach for this rotation. METHODS: Students are presented with a clinical "paper" case daily, integrating as many of the pathology disciplines as possible to demonstrate the interdependence of the various disciplines. They receive chemical pathology tutorials, visit the various laboratories, and receive practical training in fine needle aspiration biopsy. On the final day, the case studies are assessed and discussed. RESULTS: Most students appreciated all activities. This rotation enhanced student interactivity and autonomy and guaranteed immediate feedback. On evaluation of the rotation it was found that the students enjoyed the rotation, learnt something new, and realised the value of group work. CONCLUSIONS: This innovation integrates pathology with clinical practice and illustrates the use of laboratory medicine in the management of common diseases seen in this country. Students appreciate learning practical skills and having to request special investigations under a pathologist's supervision changes their approach to pathology requests. Familiarity with the pathology environment empowers the student to use pathology with greater ease. A bank of case studies that can be expanded to include all medical disciplines will facilitate the application of a problem based approach and enhance communication between the basic science disciplines and the clinical and pathology disciplines.

Biopsy, Fine-Needle↗
PubMed2006

[Simultaneous rupture of a patellar tendon and contralateral quadriceps tendon].

The simultaneous bilateral rupture of the quadriceps tendon is a rare injury; only occasional reports exist about the bilateral simultaneous rupture of the patellar tendon. Degenerative changes of the tendon due to drugs or diseases lead to the rupture. We describe two cases of simultaneous rupture of the patellar and contralateral quadriceps tendons; only one patient had special risks. We report the management of therapy and the functional results using the Lysholm score and Knee Rating Scale.

Adult↗
PubMed2006

[Right atrial ablation of ectopic atrial tachycardia using a 20-pole mapping catheter].

INTRODUCTION: Ectopic atrial tachycardia (EAT) are frequently unresponsive to pharmacological antiarrhythmic therapy. Radiofrequency ablation seems to be a safe approach to treat those arrhythmias. In the present study we report our results of radiofrequency ablation of EAT with a new mapping system (Stablemapr, Medtronic). METHODS: Thirty consecutive patients with right atrial tachycardia were included in the study. In 15 patients (G1) the 20-polar Stablemapr was used for localization of the arrhythmia foci. Data were compared with a control group (G2, n=15), in which mapping was performed conventionally. The demographic characteristics and the distribution of the different cardiac diseases were comparable in both groups. In group 1 the identification of the EAT was facilitated by the placement of the 20-pole mapping catheter in the right atrium. In group 2 point by point measurements were performed to find the earliest local atrial activation compared to a reference electrode in the high right atrium (activation mapping), or foci were identified by analysis of the P-wave morphology during stimulation (pacemapping). RESULTS: It was possible to successfully ablate all atrial tachycardias. The distribution of the foci was similar in both groups (G1/G2): near to the superior (3/5) and inferior (1/0) caval vene ostium, on the free wall (3/3), at the coronary sinus ostium (3/3) and on the interatrial septum (5/4). The mean procedure (G1: 88+/-33 vs G2: 151+/-61 min; p= or <0.05) and fluoroscopic times (G1: 19+/-9 vs G2: 38+/-28 min; p= or <0.05) were significantly shorter in group 1. Moreover, the mean number of radiofrequency applications was reduced significantly by using the new mapping system (G1: 10+/-10 vs G2: 16+/-13; p= or <0.05). CONCLUSION: Radiofrequency ablation of EAT with right atrial focus can be performed safely and successfully using a 20-pole mapping catheter. The greatest advantages compared to conventional mapping and ablation strategies lies in the shortened investigation and fluoroscopic time.

Body Surface Potential Mapping↗
PubMed2006

[Long-term functional and aesthetic sequelae after complex facial trauma associated with a mild brain injury].

INTRODUCTION: Most victims of complex facial trauma will have permanent sequelae. The goal of our work was to evaluate, by means of a retrospective study, the long-term sequelae in these patients. MATERIAL AND METHOD: 102 victims of complex facial trauma were treated in our department between 1995 and 2000. Twenty-four could be re-examined in 2006 in order to evaluate their long-term sequelae. All the patients suffered a mild brain injury. RESULTS: The overall satisfaction rate was good (19/24), but all patients presented either functional or aesthetic sequelae. The major functional sequelae were dental lost (17/24), sensory impairment of the trigeminal nerve (15/24), partial or complete loss of vision (10/24), pain (10/24), hypo- or anosmia (9/24), stenosis of the lacrimal ducts (8/24) and symptomatic deviation of the nasal septum (7/24). The main esthetic sequelae were facial scarring (23/24), facial asymmetry (13/24), dystopia of the eyeball (11/24) and modification of the aspect of the nose (10/24). DISCUSSION: The prognosis of severe facial trauma is highly dependent on the quality of the initial pluridisciplinary care. Secondary revision procedures are technically more difficult and only enable partial resolution of persisting sequelae. Thus, primary single-course surgical procedures should be a priority, recognizing that complete recovery is almost always illusory.

Adolescent↗
PubMed2006

[Total work disability: a national inquiry in France].

Physicians are often asked to draft a descriptive medical certificate for victims of traumatic maxillofacial injuries. Among other requisites, this certificate must mention the subject's total work disability. If the injury results from intentional or unintentional assault and battery, the duration of the work disability will determine the competence of the court that will try and condemn the perpetrator. Thus the total work disability certificate has penal value and should be used only for this purpose. Using the data acquired from a national inquiry in France, we evaluated common practices among a panel of maxillofacial teams concerning the information mentioned on the initial medical certificate and, in particular, the duration of work disability allocated for the most frequent facial fractures. The aim of this study was to establish, based on the observed practices, whether it would be licit to propose a total work disability scale for maxillofacial trauma.

Disability Evaluation↗
PubMed2006

Monitoring minimal residual disease by quantification of genomic chromosomal breakpoint sequences in acute leukemias with MLL aberrations.

An estimated 10% of acute leukemias carry mixed-lineage leukemia (MLL) fusion genes. Approximately 50 different fusion partners of the MLL gene have already been molecularly identified. These leukemias are commonly regarded as high-risk cases and are treated accordingly with intensified therapy regimens, including hematopoietic stem cell transplantation. However, a subset of patients may achieve long-term remissions with conventional therapy. Monitoring minimal residual disease (MRD) is undoubtedly of great value in clinical decision making, also in the pre- and post-transplant setting. Here, we describe a novel method for detecting MRD in leukemias with MLL aberrations. The method is based on monitoring patient-specific chromosomal breakpoint DNA sequences. This has several advantages over other methods that are based either on detecting specific RNA molecules of MLL fusion genes or on surrogate markers. An accurate and absolute quantification of the MRD level is possible. No reference to housekeeping genes is necessary and the target structure is much more stable than any mRNA fusion transcript.

Acute Disease↗
PubMed2006

The MLL recombinome of acute leukemias.

Chromosomal rearrangements of the human MLL gene are a hallmark for aggressive (high-risk) pediatric, adult and therapy-associated acute leukemias. These patients need to be identified in order to subject these patients to appropriate therapy regimen. A recently developed long-distance inverse PCR method was applied to genomic DNA isolated from individual acute leukemia patients in order to identify chromosomal rearrangements of the human MLL gene. We present data of the molecular characterization of 414 samples obtained from 272 pediatric and 142 adult leukemia patients. The precise localization of genomic breakpoints within the MLL gene and the involved translocation partner genes (TPGs) was determined and several new TPGs were identified. The combined data of our study and published data revealed a total of 87 different MLL rearrangements of which 51 TPGs are now characterized at the molecular level. Interestingly, the four most frequently found TPGs (AF4, AF9, ENL and AF10) encode nuclear proteins that are part of a protein network involved in histone H3K79 methylation. Thus, translocations of the MLL gene, by itself coding for a histone H3K4 methyltransferase, are presumably not randomly chosen, rather functionally selected.

Acute Disease↗
PubMed2006

Regular insulin secretory oscillations despite impaired ATP synthesis in Friedreich Ataxia patients.

Friedreich Ataxia is an inherited disorder caused by decreased expression of a mitochondrial protein called frataxin. Deficiency of this protein causes reduced biogenesis of iron-sulfur clusters, and subsequently impaired synthesis and replenishment of ATP IN VIVO. Basal secretion of insulin occurs in an oscillating manner presumably triggered by ATP-dependent feedback inhibition of glycolytic flux. Hence, individuals with reduced ATP synthesis rates should possibly exhibit impaired insulin secretory oscillations if these were solely dependent on ATP. In the present study Friedreich Ataxia patients with a presumptive impairment of ATP synthesis in pancreatic beta-cells were evaluated for regularity of basal secretory oscillations of insulin. Healthy siblings were employed as controls. In conflict with the initial hypothesis, no differences in regards to oscillation patterns were observed between patients and controls. Supported by EX VIVO evidence, these findings tentatively suggest that pulsatile insulin secretion might not be exclusively dependent on ATP feedback inhibition in humans.

Adenosine Triphosphate↗
PubMed2006

Why do idiopathic scoliosis patients participate more in gymnastics?

The influence of physical and sporting activities (PSA) on idiopathic scoliosis (IS) is still obscure. The aim of this study was to investigate whether such an influence exists and if so, to determine its characteristics. Two hundred and one teenagers with IS and a control group of 192 adolescents completed an epidemiological questionnaire. Those practising gymnastics were more numerous in the IS group than in the control group. Moreover, the practice of gymnastics was chosen before IS was diagnosed. As gymnastic activities are considered neither as a therapy nor as a precursor of IS, the distribution observed could be linked to a common factor that both increases the likelihood of IS and favors the practice of gymnastics. Joint laxity (JL) may be such a common factor, and was therefore tested (wrist and middle finger) on 42 girls with IS and 21 girls of a control group. IS patients, practising gymnastics or not, showed a higher JL than the control group practising gymnastics or not. Furthermore, the groups practising gymnastic activities did not show higher JL levels than the other groups. Children with a high JL could be drawn toward gymnastics because of their ability to adapt to the constraints of this sport. Girls with a high JL may therefore be prone to developing IS. The fact that most teenagers with IS practise gymnastics could be related to a higher JL.

Adolescent↗