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Biomedical subjects

A Beyer

Publications and source records attributed to A Beyer.

At least 19 recordsLinked to original sources
PubMed2006

Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): standardized protocol and reference values.

The nationwide multicenter trials of the German Research Network on Neuropathic Pain (DFNS) aim to characterize the somatosensory phenotype of patients with neuropathic pain. For this purpose, we have implemented a standardized quantitative sensory testing (QST) protocol giving a complete profile for one region within 30 min. To judge plus or minus signs in patients we have now established age- and gender-matched absolute and relative QST reference values from 180 healthy subjects, assessed bilaterally over face, hand and foot. We determined thermal detection and pain thresholds including a test for paradoxical heat sensations, mechanical detection thresholds to von Frey filaments and a 64 Hz tuning fork, mechanical pain thresholds to pinprick stimuli and blunt pressure, stimulus/response-functions for pinprick and dynamic mechanical allodynia, and pain summation (wind-up ratio). QST parameters were region specific and age dependent. Pain thresholds were significantly lower in women than men. Detection thresholds were generally independent of gender. Reference data were normalized to the specific group means and variances (region, age, gender) by calculating z-scores. Due to confidence limits close to the respective limits of the possible data range, heat hypoalgesia, cold hypoalgesia, and mechanical hyperesthesia can hardly be diagnosed. Nevertheless, these parameters can be used for group comparisons. Sensitivity is enhanced by side-to-side comparisons by a factor ranging from 1.1 to 2.5. Relative comparisons across body regions do not offer advantages over absolute reference values. Application of this standardized QST protocol in patients and human surrogate models will allow to infer underlying mechanisms from somatosensory phenotypes.

Adolescent↗
PubMed2006

Do patients with skin allergies have higher levels of anxiety than patients with allergic respiratory diseases? Results of a large-scale cross-sectional study in a French population.

BACKGROUND: Psychological comorbidity is a known aspect of allergic disease. However, there is recent evidence that a large proportion of allergic patients remains undiagnosed and untreated for psychological disease. In addition, the complexities of the anxiety-allergy relationship, i.e. differences for current and past disease, or differences among allergic disease types, are not well understood. OBJECTIVES: To measure the level of anxiety in a large allergic population in France using a standardized measure, the State/Trait Anxiety Inventory (STAI). METHODS: Allergy patients in France (n = 3939) who visited their allergy specialists participated in the study. The patients completed a questionnaire which was then linked to the questionnaire completed by their physician. Only patients with both subject and physician questionnaire were kept in the analyses. Mean STAI scores for the State (S) and Trait (T) scales were obtained for each allergic disease. ANCOVA models testing group differences on the mean scores, using the categories "current disease", "past disease" and "allergic disease ever", were assessed along with relevant confounders. RESULTS: Allergic rhinitis (AR), asthma and atopic dermatitis (AD) were the most prevalent conditions of the 12 allergic diseases assessed in the study. Women had higher mean STAI S/T scores than men and age was also found to be associated with higher S scores; therefore, both age and gender were included as covariates where relevant. A single ANCOVA model for each STAI scale showed a statistical difference among the various allergic diseases. Using the category "current disease" each allergic disease was assessed separately regarding the presence or absence of that disease. Higher, statistically significant mean STAI scores were found for AD and allergic urticaria on the S scale and for AD on the T scale. Similarly, for the category "allergic disease ever", AD and allergic urticaria reached statistical significance on the S scale, while on the T scale only AD was statistically significant. When patients were assessed for anxiety based on their past disease, asthma, AR and sinusitis were significant on the S scale while asthma and nasal polyps were statistically significant on the T scale. When asthma and AD were tested simultaneously, only the latter was significant. CONCLUSIONS: High mean scores for State and Trait anxiety were mostly associated with AD.

Adolescent↗
PubMed2005

[Endogenous cannabinoid system. Effect on neuronal plasticity and pain memory].

AIM: The aim of this study was to evaluate the role of the endogenous cannabinoid system in controlling neuroplasticity. METHODS: The pain threshold for electrical stimuli was determined in transgenic mice lacking the cannabinoid receptor type 1 (CB1(-/-)) and in the corresponding respective wild-type animals. Electrophysiological experiments were performed in prepared brain slices to test the effect of endogenous and exogenous cannabinoids on synaptic transmission and long-term potentiation (LTP) in the amygdala. RESULTS: The pain threshold was nearly identical in both groups for the first pain induction; however, with repeated pain induction it decreased to a significantly greater extent in the CB1(-/-) mice than in the wild-type animals. Synoptic transmission and the inducibility of LTP were not influenced by the acute pharmacological blockade of CB1 receptors, but inhibited by the CB1 agonist WIN55,212-2. CONCLUSION: The endogenous cannabinoid system is involved in the control of neuroplasticity as part of pain processing . Cannabinoids prevent the formation of LTP in the amygdala via activation of CB1 receptors. Synoptic transmission and the inducibility of LTP were not influenced by the acute pharmacological blockade of CB1 receptors, but inhibited by the CB1 agonist Win55,212-2.

Cannabinoids↗
PubMed2005

[Evaluation of sympathicolysis after continuous brachial plexus analgesia using laser Doppler flowmetry in patients suffering from CRPS I].

OBJECTIVE: The aim of this study was to evaluate continuous brachial plexus analgesia in terms of pain relief and sympathicolysis in patients suffering from CRPS I. METHODS: A detailed clinical examination comprised measurement of temperature changes (Infrared Thermometry), pain rating (VAS scale) and assessment of peripheral sympathetic nervous function using laser Doppler flowmetry. A total number of 12 patients (mean age: 56 +/- 9 years, range: 30 to 69 years) received continuous brachial plexus analgesia after placing a catheter in the perineurial sheath of the brachial plexus through an axillary approach. Prior to continuous analgesia (Morphin 0.04 mg/ml, Clonidin 1.5 microg/ml, Bupivacaine 0.0625 %) running at 4 ml/h a test dosis of 20 ml Bupivacaine 0.25 % was applied to establish brachial plexus block. RESULTS: After an equilibration period of 2 hours, consecutive pain measurements revealed sufficient pain relief in 9 out of 12 patients (75 %) with a mean pain rating dropping from 4.7 +/- 0.68 to 1.59 +/- 1.02 (p < 0.001). Pain reduction was accompanied by a significant temperature increase from -0.78 degrees C to 1.7 degrees C (p < 0.05). However measurement of sympathetic function by laser Doppler flowmetry revealed that no significant sympathicolysis occurred. CONCLUSIONS: The study shows that clinical investigation of temperature change is not reliable in the evaluation of sympathicolysis. This is of special interest in patients who are suspected of having sympathically maintained pain (SMP) and are treated by brachial plexus analgesia.

Adult↗
PubMed2004

Dynamic simulation of protein complex formation on a genomic scale.

MOTIVATION: One of the central questions in the post-genomic era is the understanding of protein-protein interactions and of protein complex formation. It has been observed that protein complex size distributions of the yeast Saccharomyces cerevisiae decay exponentially. The shape of these size distributions reflects mechanisms of protein complex association and dissociation. RESULTS: We present the most simple dynamic model that is able to reproduce the observed protein complex size distribution for yeast. This protein association-dissociation model (PAD-model) simulates the dynamics of protein complex formation on a genomic scale for about 50 million protein molecules. By ruling out different model variants it is possible to elucidate fundamental features of the protein complex dynamics, e.g. complex association is independent of complex size. In addition, the PAD-model provides information about the complexity of the yeast proteome and it gives an idea of how many complexes could not be identified during the measurements. AVAILABILITY: All programs used for this publication are available on request from the authors. CONTACT: beyer@imb-jena.de SUPPLEMENTARY INFORMATION: Supplementary information about the model and its interpretation can be downloaded from http://www.imb-jena.de/tsb/pad.

Computer Simulation↗
PubMed2004

[The norovirus-epidemic in Berlin - clinic, epidemiology, and prevention].

INTRODUCTION: During the winter 2002/2003, an increased number of outbreaks of acute gastroenteritis caused by norovirus was reported from Germany, some other European countries and the USA. In this study, the epidemiological and clinical features of the Berlin norovirus outbreak were investigated in order to identify the reasons for the spread of norovirus gastroenteritis and possible control measures. METHODS: Cases and spread of norovirus infection in eleven long-term care facilities and a university hospital in Berlin were monitored from October 2002 to February 2003. To investigate the symptomatology and routes of transmission, a retrospective and interview-based study of infected staff members was performed. RESULTS: Norovirus outbreaks in eleven long-term care facilities affected 314 patients (attack rate: 28.3 %, rate of hospitalisation: 20.7 %). 219 persons were affected in the hospital, during a period of four months. Sequence analysis revealed the circulation of Norovirus genogroup II (Grimsby-like viruses). The mean duration of symptoms was 69 hours. The duration of outbreaks on specific wards was negatively correlated with the time of returning to work (mean: 1.8 days) of the staff members after the disease. DISCUSSION: This report demonstrates the potential of norovirus to cause large outbreaks by person to person transmission. Spread by aerosols generated by vomiting and environmental contamination seem to be particular important in institutional settings. The duration of symptoms was longer than reported previously, reflecting a possible increased virulence. Besides this, the outbreak was facilitated by insufficient preventive measures.

Adult↗
PubMed2002

Knowledge, compliance and practice of antibiotic endocarditis prophylaxis of patients with congenital heart disease.

The aim of this study was to determine the knowledge, compliance, and practice of antibiotic endocarditis prophylaxis (AEP) for patients with congenital heart disease (CHD) during various diagnostic or therapeutic procedures. Patients (296) and their parents were interrogated during a visit with an 18-question survey pertaining to the practice of AEP. Most patients (91.6%) had acyanotic congenital heart disease, usually preoperative (45.3%), or had high risk of infective endocarditis due to previous endocarditis (2.0%), cyanosis (8.4%), or prosthetic valves (5.4%). Potential sources for failure of AEP were (1) no existence of a wallet card (6.8%), no communication between patient and doctor concerning the potential risk of endocarditis during a visit (13.2%), or no sufficient anamnestic inquiry by the physician before procedures were performed (43.2%). The patients underestimated (4.4%) or had no knowledge of the individual risks of endocarditis (37.5%) or underestimated indication for AEP (11.1%). AEP was often not performed at all (60.5%). Bad dental status with no previous dental therapy (35.5%) and a high rate of caries (17.2%) or gingivitis (7.4%) even in young children was frequent. AEP for patients with CHD has not been sufficiently used because of the patient's, and the physician's failure to take the necessary steps, the cardiac diagnosis, or the dental health status. Alternative strategies in prophylaxis for AEP are discussed here.

Adolescent↗
PubMed2002

[Electric stimulation acupuncture in peripheral neuropathic pain syndromes. Clinical pilot study on analgesic effectiveness].

AIM: The aim of this pilot study was to investigate the potential value of acupuncture in the treatment of peripheral neuropathic pain. Explorative analysis should provide data for further randomised controlled trials. METHOD: In an uncontrolled clinical trial electroacupuncture was given to 17 patients with chronic neuropathic pain of peripheral origin which was resistant to preceding pain therapy. Patients were treated twice weekly for 4 weeks. Assessment of outcome measurements comprised: Intensity of continuous pain (visual analogue scale, VAS), intensity of pain attacks (VAS), duration of pain attacks, number of pain attacks and changes in mood (VAS). All measures were evaluated by diary (1 week before treatment to 2 weeks after treatment and 1 week at follow up three months after treatment). Changes of global complaints and patients' beliefs in treatment (credibility assessment) were also assessed. RESULTS: At re-evaluation two weeks after treatment, mean continuous pain was reduced by 32.9% and intensity of pain attacks was reduced by 59%. Mean number of daily pain attacks decreased from 4.2 (SD +/- 4.6, 0.14-13.3) before treatment to 2.2 (SD +/- 3.8, 0-7.5) two weeks after treatment. Duration of pain attacks and mood showed no substantial changes. Three months after treatment, continuous pain was reduced by 15.9% and intensity of pain attacks was reduced by 44% compared to baseline. No serious adverse events were observed CONCLUSIONS: On the basis of this small pilot study, trial treatment by electroacupuncture seems to be justified in these patients given a lack of success of standard treatments. The apparent beneficial analgesic effects of electroacupuncture appear to warrant further investigation.

Acupuncture Analgesia↗
PubMed2002

[Neurobiological mechanisms of acupuncture analgesia].

AIM: The aim of this review is to present the findings of basic research about mechanism of acupuncture-induced analgesia (AA) on the basis of the relevant literature. The transferability of the results into practice and theory of traditional acupuncture are critically discussed. METHOD: Extensive literature research was used to identify and summarize relevant studies. RESULTS: AA has been proven by biochemical, immunohistochemical, molecular biological and neurophysiological investigations. It has been shown that short term AA is mediated by an activation of endogenous antinociceptive systems and descending inhibitory systems. Long term effects cannot be explained sufficiently by experimental results; however, they suggest an involvement of long term inhibitory synaptic modification at spinal cord neurons and clinical and radiological findings indicate limbic system modulation. CONCLUSION: Regarding the complexity of endogenous pain-inhibitory systems and the methodological shortcomings many questions remain unanswered. Further research activities are necessary in this field.

Acupuncture Analgesia↗
PubMed2001

Mammalian cells express two VPS4 proteins both of which are involved in intracellular protein trafficking.

The yeast Vps4 protein (Vps4p) is a member of the AAA protein family (ATPases associated with diverse cellular activities) and a key player in the transport of proteins out of a prevacuolar endosomal compartment. In human cells, we identified two non-allelic orthologous proteins (VPS4-A and VPS4-B) of yeast Vps4p. The human VPS4-A and VPS4-B proteins display a high degree of sequence identity to each other (80 %) and to the yeast Vps4 protein (59 and 60 %, respectively). Yeast cells lacking a functional VPS4 gene exhibit a temperature-sensitive growth defect and mislocalise a carboxypeptidase Y-invertase fusion protein to the cell surface. Heterologous expression of human VPS4 genes in vps4 mutant yeast strains led, in the case of human VPS4-A, to a partial and, in the case of human VPS4-B, to a complete suppression of the temperature-sensitive growth defect. The vacuolar protein sorting defect of vps4 mutant yeast cells was complemented completely by heterologous expressed human VPS4-B protein, and partially by the human VPS4-A protein. Expression of mutant human VPS4-A (E228Q) and VPS4-B (E235Q) proteins, harbouring single amino acid exchanges in their AAA domains, induced dominant-negative vacuolar protein sorting defects in wild-type yeast cells in both cases. Two-hybrid experiments suggest that the human VPS4-A and VPS4-B proteins can form heteromeric complexes, and subcellular localisation experiments indicate that both human VPS4 proteins associate with endosomal compartments in yeast. Based on these results, we conclude that both human VPS4 proteins are involved in intracellular protein trafficking, presumably at a late endosomal protein transport step, similar to the Vps4p in yeast.

ATPases Associated with Diverse Cellular Activitie↗
PubMed2001

[Important acute measures after fractures. Rapid and adequate treatment of pain].

Pain caused by bone fractures needs to be treated promptly and adequately to avoid negative secondary effects. Pain therapy and the healing of soft tissue are goals that are equally as important as healing of the fracture. The following factors have analgesic potential: reduction, immobilization, cooling measures, limb elevation and fasciotomy. Symptomatic treatment of pain is orientated to the WHO stepped approach, which attaches particular importance to the regular administration of analgesics, as dictated by clinical effectiveness.

Analgesics↗
PubMed2001

[When fracture pain does not subside. Recognizing complications].

Over the long term, the evolution of pain caused by fractures is determined by the quality of immobilization, the extent of edema, and by surgical, analgesic and physiotherapeutic treatment. Development of chronicity is initiated by secondary deterioration, persistence of pain in the absence of improvement, changes in the nature of the pain, its spontaneous occurrence, and the appearance of concomitant symptoms. Differential diagnostic considerations must include surgical complications, but also damage to nerves, or the complex regional pain syndrome (CRPS). A particular differential diagnostic problem is the differentiation between CRPS and other complications. Treatment must be matched to the diagnosis: conservative attempts at treatment may have to be followed up with surgical revision. Drug treatment of pain is oriented to the stepped WHO schema. Physiotherapy, physical treatment and ergotherapy play a major role in the treatment of CRPS.

Chronic Disease↗
PubMed2001

Randomised trial of acupuncture compared with conventional massage and "sham" laser acupuncture for treatment of chronic neck pain.

OBJECTIVES: To compare the efficacy of acupuncture and conventional massage for the treatment of chronic neck pain. DESIGN: Prospective, randomised, placebo controlled trial. SETTING: Three outpatient departments in Germany. PARTICIPANTS: 177 patients aged 18-85 years with chronic neck pain. INTERVENTIONS: Patients were randomly allocated to five treatments over three weeks with acupuncture (56), massage (60), or "sham" laser acupuncture (61). MAIN OUTCOME MEASURES PRIMARY OUTCOME MEASURE: maximum pain related to motion (visual analogue scale) irrespective of direction of movement one week after treatment. SECONDARY OUTCOME MEASURES: range of motion (3D ultrasound real time motion analyser), pain related to movement in six directions (visual analogue scale), pressure pain threshold (pressure algometer), changes of spontaneous pain, motion related pain, global complaints (seven point scale), and quality of life (SF-36). Assessments were performed before, during, and one week and three months after treatment. Patients' beliefs in treatment were assessed. RESULTS: One week after five treatments the acupuncture group showed a significantly greater improvement in motion related pain compared with massage (difference 24.22 (95% confidence interval 16.5 to 31.9), P=0.0052) but not compared with sham laser (17.28 (10.0 to 24.6), P=0.327). Differences between acupuncture and massage or sham laser were greater in the subgroup who had had pain for longer than five years (n=75) and in patients with myofascial pain syndrome (n=129). The acupuncture group had the best results in most secondary outcome measures. There were no differences in patients' beliefs in treatment. CONCLUSIONS: Acupuncture is an effective short term treatment for patients with chronic neck pain, but there is only limited evidence for long term effects after five treatments.

Acupuncture Analgesia↗