Biomedical subjects
A Klauser
Publications and source records attributed to A Klauser.
Preferential type 1 chemokine receptors and cytokine production of CD28- T cells in ankylosing spondylitis.
OBJECTIVE: To examine serum levels of type 1 and type 2 chemokines and lymphocytic expression of chemokine receptors, and to compare the results with lymphocytic cytokine production in patients with ankylosing spondylitis (AS). METHODS: Twelve patients with AS (mean (SD) age 44.9 (14.7) years) and 27 healthy controls (46.4 (12.8) years) were enrolled into the study. The expression of chemokine receptors (CCR-5, CXCR-3, CCR-4) and cytokines (interferon gamma (IFNgamma), interleukin (IL)2, IL4, IL10, tumour necrosis factor alpha (TNFalpha)) on CD28(+) and CD28(-) T cell subtypes was analysed by a three colour FACS technique of peripheral blood samples. Serum ELISAs were performed to detect the CCR-5 ligands CCL-5, CCL-3; the CXCR-3 ligands CXCL-10, CXCL-9; and the CCR-4 ligand, CCL-17 before and after administration of the TNFalpha blocking agent infliximab. RESULTS: CD4(+)CD28(-) T cells had higher ratios of CXCR-3 to CCR-4 than CD4(+)CD28(+) T cells. Both, CD4(+) and CD8(+)CD28(-) T cells of patients with AS produced more IFNgamma, TNFalpha, and IL10 than their CD28(+) counterparts (p<0.05), and lacked the production of IL2 and IL4. Serum levels of CXCL-9 were increased in patients with AS to 59.2 pg/ml (34.1-730.5) compared with 32.5 pg/ml (20.0-79.5) in healthy controls (p = 0.016). The levels of both type 1 (CCL-5, CXCL-9) and type 2 chemokines (CCL-17) decreased under blockade of TNFalpha (p<0.05). CONCLUSIONS: The profile of chemokine receptor expression and cytokine production by CD28(-) T cells suggests a type 1 immune reaction in AS, although IL10 is frequently produced by CD28(-) T cells. Treatment with TNFalpha blocking antibodies decreased both types of chemokines in patients' sera.
High positive predictive value of specific antibodies cross-reacting with a 28-kDa Drosophila antigen for diagnosis of ankylosing spondylitis.
OBJECTIVES: Diagnosis of ankylosing spondylitis (AS) can be difficult, and a specific laboratory test has not yet been introduced as a routine diagnostic tool. Our aim was to evaluate the diagnostic value of antibodies specifically binding to a recombinant 28-kDa antigen for the diagnosis of AS. METHODS: Blinded sera were tested for antibodies binding to the procaryotically expressed 28-kDa protein using an enzyme-linked immunosorbent assay (ELISA). This purified 28-kDa protein is produced by a specific clone from an embryonic Drosophila hydei Xgtl I c-DNA library and is bound by human antibodies cross-reacting with both a 36-kDa protein of chromosomes from Drosophila melanogaster and a 69-Da HeLa S3 protein potentially involved in signal transduction pathways. RESULTS: Serum concentrations of antibodies cross-reacting with this specific antigen were increased in 371 patients with AS compared with 37 healthy controls (39.5 vs 22.6 U/ml; P = 0.004). The positive predictive values of this ELISA test for AS were between 95.1% (95% confidence interval 90.6-97.9%) for a cut-off level of 50 U/ml and 97.4% (92.7-99.5%) for a cut-off level of 75 U/ml, and the sensitivities were between 42.1% (37.0-47.3%) for a cut-off level of 50 U/ml and 30.7% (26.1-35.7%) for a cut-off level of 75 U/ml. CONCLUSIONS: Serum ELISA tests for antibodies cross-reacting with the 28-kDa antigen show a high positive predictive value for AS of more than 95%.
[Ultrasound contrast agents and prostate cancer].
Prostatic carcinoma is the most frequent malignant disease in men and associated with very high mortality. The diagnostic work-up of prostatic carcinoma is based on tests to determine the level of prostate-specific antigen (PSA), digital rectal examination, and transrectal sonography. Due to diagnostic limitations, ultrasound-guided prostate biopsy is the method of choice for diagnosis of prostatic carcinoma. New imaging technologies allow detection of prostatic carcinoma, thus facilitating removal of specific biopsy specimens from these regions. Introduction of ultrasound contrast agents ("echo signal enhancers") significantly increased the diagnostic potential of this method, making it possible to visualize tumor vascularization.
[Transrectal three dimensional sonography. Techniques and indications].
In 3-D transrectal ultrasound it is possible, for the first time, to investigate the region of interest in three planes simultaneously. Exact examination of the organs of the small pelvis as well as of pathologic changes in the region of the pelvic floor can be performed with this new imaging technique. The bulbourethral glands can be investigated routinely, which enables the diagnosis of cysts of these glands. The prostatic zones, their relations as well as the growth of the transitional zone during the development of benign prostatic hyperplasia can be visualized. Furthermore, 3-D transrectal ultrasound allows investigation of morphology and function of the rhabdosphincter. The contractility of the muscle can be quantified. 3-D ultrasound guided puncture and drainage of prostatic abscesses represents a minimally invasive therapeutic modality. This technique can be used to place needles as well as implants in the lower urinary tract. Generally, 3-D transrectal ultrasound offers new diagnostic and therapeutic possibilities.
Lower esophageal sphincter pressure in patients with gastroesophageal reflux diseases and posture and time patterns.
Gastroesophageal reflux disease is caused predominantly by lower esophageal sphincter insufficiency. Reports suggest that it is possible to distinguish between two main mechanisms causing reflux: low basal sphincter pressure leading to free reflux, mostly occurring at night in the supine position, and increased transient lower esophageal sphincter relaxations with normal or increased resting pressure leading to reflux during the day in an upright position. Lower esophageal sphincter pressure (LESP)-- s determined by stationary pull-through manometry--was compared to profiles of acidic reflux measured by 24-h pH monitoring in 207 patients with proven gastroesophageal reflux disease. Differences in LESP were not significant among patients with reflux predominantly during the day in an upright position and those with reflux predominantly at night in a supine position (16.1 +/- 7.4 mmHg versus 15.1 +/- 7.8 mmHg; t-test: P = 0.355). For both patterns of LESP, there was a slight negative correlation with the amount of acidic reflux (determined as a percentage of time with pH < 4). Pearson correlation coefficients were -0.196 for upright refluxers and -0.137 for bipositional/supine refluxers (P = 0.006 and P = 0.049, respectively). As there are no differences in LESP with regard to posture or time patterns of acidic reflux it seems unlikely that upright reflux is associated with increased LESP, whereas supine reflux manifests due to a hypotensive LESP. Alternatively, it may be concluded that stationary pull-through manometry is inadequate for determining the cause of gastroesophageal reflux disease and is therefore of limited use in its routine diagnosis.
[The value of ultrasound (US) in the diagnosis of prostate cancer].
The value of ultrasound (US) in the diagnosis of prostate cancer has increased in importance in the past decade, which is mainly related due to the increasing incidence of prostate cancer, the most common malignancy in men. The value of conventional gray-scale US for prostate cancer detection has been extensively investigated. The introduction of US contrast agents has dramatically changed the role of US for prostate cancer detection. Advances in US techniques were introduced to further increase the role of US contrast agents. Although most of these advances in US techniques, which use the interaction of the contrast agent with the transmitted US waves are very sensitive for the detection of microbubbles, are mostly unexplored, in particular for prostate applications. First reports of contrast-enhanced US investigations of blood flow of the prostate have shown that contrast-enhanced US adds important information to the conventional US technique. We present a critical evaluation of the current status of transrectal US imaging for prostate cancer detection. Furthermore, we give background information on US contrast agents and imaging modalities. Early results of contrast-enhanced US suggest the feasibility of the use of US contrast agents to enhance US imaging of the prostate. The application of US contrast agents for the detection and clinical staging of prostate cancer is promising. However, future clinical trials will be needed to determine the promise of contrast-enhanced US of the prostate evolves into clinical application.
[Lymph node tuberculosis in a patient with polymyalgic symptoms: value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)].
18F-FDG-PET studies were performed in a 60-year-old female patient with polymyalgia rheumatica resistant to prior corticosteroid treatment. PET studies showed a cervical focus, which was identified histologically and microbiologically as lymph node tuberculosis.
18F-fluorodeoxyglucose-positron emission tomography: a new explorative perspective.
18F-Fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) is a new functional imaging technique available for clinical and experimental use. 18F-FDG-PET studies can be used for screening, localization and follow-up of hypermetabolic processes including malignancies, infections and autoimmune processes. For several years it has been applied in oncological, cardiological and neurological patients, but nowadays an increasing number of studies favours its use in patients with autoimmune diseases including large vessel arteritis. From the experimental view, this technique has even become more important since the introduction of a small PET scanner for the use in animal models. This review focuses on technical aspects, clinical experiences and experimental and future perspectives of 18F-FDG-PET, with a special emphasis on large vessel vasculitis and other autoimmune diseases.
[Diagnosis of climbing related overuse injuries].
Sport climbing shows an enormous increase in participation, evolving to more popularity, including even school sport activity on high standards. Therefore the number of climbing related injuries is increasing and becomes a more frequently encountered medical problem. Typical climbing associated injuries involve predominantly the upper limb. Overuse injuries are the most common climbing related injuries. The clinical examination is the first line investigation, which is often limited especially in the acute phase. However, an exact diagnosis is desirable for therapeutic management. Imaging modalities have shown to be capable for detection of climbing related injuries. An overview about the current use of x-ray, ultrasound and magnetic resonance imaging in different climbing related overuse injuries is presented.
[Contrast-medium enhanced reflux ultrasound in children. A comparison with radiologic imaging up to now].
Voiding cystourethrography (VCUG) has long been the method of choice for the diagnosis of vesicoureteral reflux (VUR). Especially in the course of conservative treatment, the radiation dose involved might become quite high over the years. Since the development of such ultrasound echo-enhancing agents as Levovist (Schering, Germany), we now have the ability to assess the diagnostic efficacy of this agent in the evaluation of VUR with a view to replacing VCUG with the radiation-free ultrasound methodology. A total of 104 children with a mean age of 5.4 years were examined using echo-enhancing ultrasound after informed consent had been obtained from their parents. For control purposes, all children were examined by standard VCUG as well. The diagnosis of VUR was judged to be positive when microbubbles appeared in the ureter or renal pelvis. Correlations were sought between the sonographic findings and those obtained by standard VCUG. In 76 (37%) of the 208 ureter-kidney units investigated, VUR was detected by both technologies. VUR was diagnosed by ultrasonography only in 5 units and by VCUG only only in 3 units. All reflux grades (I-V) were identified. The specificity and sensitivity of the contrast reflux ultrasound were significantly high. The long contrast time of up to 30 min combined with the high contrast effect resulted in convincing images with high levels of diagnostic confidence. Our results clearly demonstrate that the safety and accuracy of the diagnosis of VUR by means of contrast-enhanced ultrasound is statistically comparable to those of standard radiologic VCUG. Therefore, this methodology is an exceptional approach to reducing the number of children being exposed to ionising radiation especially during conservative follow-up of children with reflux.
Detection of prostate cancer with a microbubble ultrasound contrast agent.
The diagnosis of prostate cancer is currently limited by the low sensitivity and specificity of systematic conventional grey-scale ultrasonography. We assessed contrast-enhanced colour Doppler ultrasonography by means of a microbubble ultrasound contrast agent to detect tumour vascularity and improve the diagnosis of prostate cancer. The use of a microbubble ultrasound contrast agent for transrectal colour Doppler targeted biopsy significantly improved the detection of prostate cancer compared with systematic biopsy following conventional grey-scale ultrasonography (p<0.001). Contrast-agent enhanced colour Doppler imaging may allow for limited targeted biopsies (five or less), which reduces costs and morbidity.
Ultrasonographic assessment of the scrotum.
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US findings in the scrotum of extreme mountain bikers.
PURPOSE: To sonographically investigate whether mountain bikers have a higher prevalence of scrotal abnormalities compared with that in nonbikers. MATERIALS AND METHODS: Eighty-five male mountain bikers (mean age, 25 years; age range, 17-45 years) and 31 healthy nonbikers (mean age, 24 years; age range, 15-37 years) were examined for scrotal findings at ultrasonography (US). Only male subjects with a history of extensive off-road biking (> or =2 h/d 6 d/wk; covered distance, >5,000 km/y) were assigned to the group of mountain bikers, whereas the control group did not engage in bicycling. In addition to clinical evaluation, US examination of the scrotum was performed by using a linear-array transducer operating at a frequency of 8.0 MHZ: RESULTS: Eighty (94%) mountain bikers had abnormal findings at scrotal US. Thirty-nine (46%) had a history of intermittent scrotal tenderness or discomfort but no severe scrotal trauma. Abnormal findings at US included scrotal calculi in 69 (81%), epididymal cysts in 39 (46%), epididymal calcifications in 34 (40%), testicular calcifications in 27 (32%), hydroceles in 24 (28%), varicoceles in nine (11%), and testicular microlithiasis in one (1%). In the control group, abnormal findings were noted in five (16%), all of whom had epididymal cysts. The overall difference in the number of scrotal abnormalities in bikers compared with the number in nonbikers was significant (P <.0001, chi2 test). CONCLUSION: US shows a significantly higher prevalence of extratesticular and testicular disorders in these mountain bikers compared with nonbikers.
Subclinical microtraumatisation of the scrotal contents in extreme mountain biking.
Mountain bikers had a high frequency of extratesticular and testicular disorders, which were associated with clinical symptoms in half the bikers. Hence a high rate of repeated microtraumatisation of the scrotal contents must be assumed.
Accuracy of 13C-urea breath test in clinical use for diagnosis of Helicobacter pylori infection.
UNLABELLED: The 13C-urea breath test (UBT) is a noninvasive test for diagnosis of Helicobacter pylori infection of gastric mucosa. The aim of this prospective study was to assess the accuracy of a simple UBT in clinical routine use. METHODS: The study population comprised of 100 patients (49 f, 51 m) requiring diagnostic upper GI endoscopy. One biopsy specimen was taken from the gastric antrum, body and fundus, respectively, for standard histological examination and one additional specimen from each location was transformed into transport medium for cultivation of H. pylori. After vaccination of the culture plates the biopsies were tested for urease activity (UAT). After recovery from endoscopy the patients had to pass an one liter endexspiratory breath sample before and 15 min after drinking 200 ml orange juice, pH 3.6, containing 75 mg of 13C-urea. 13CO2 was measured in the breath samples using isotope-selective nondispersive infrared spectrometry. RESULTS: Defining gold standard groups with all biopsy tests (from antrum and corpus) positive or negative the 13CO2 delta over baseline (DOB) cut-off level of UBT was set at 6.5/1000 in order to best discriminate positive from negative patients (ROC analysis). UBT was positive in 37% of all subjects. Taken UAT and histological examination together (positive when both tests were positive) UBT displayed a sensitivity of 92%, a specificity of 94%, a positive predictive value of 89%, and a negative predictive value of 94%. When including the results of culture sensitivity and negative predictive value reached almost 100%. The mean of the 13CO2-DOB values from H. pylori-positive duodenal or gastric ulcer patients did not differ from controls (H. pylori-positive patients without lesions). The 13CO2-DOB values of the ulcer group were correlated significantly with the active inflammatory component of gastritis in antrum, corpus, and fundus. CONCLUSION: UBT with this setup detects H. pylori infection in clinical routine use with high accuracy. The increase of exhaled 13CO2 does not predict ulcer disease but reflects the degree of active inflammation of gastric mucosa.
[Value of high-resolution ultrasound in the evaluation of finger injuries in extreme sport climbers].
AIM: To determine the value of high-resolution ultrasound in the evaluation of finger injuries and changes due to strain in the fingers of extreme rock climbers. METHODS: High-frequency ultrasound was performed on 208 fingers of 52 extreme rock climbers (mean age: 29.7 yrs) and on 80 fingers of 20 healthy volunteers (mean age: 28.5 yrs). The following parameters were sonographically assessed: thickness of the pulley-system A2, distance between phalanx and tendon (PS distance), gliding ability of the flexor tendons, and the periarticular and peri-tendinous space. The examination was performed on the handling in a supinated position with extended fingers, followed by active and passive flexion of about 40 degrees. All climbers also underwent clinical examination. RESULTS: The pulley-system of climbers showed a significantly increased thickness of 0.17 (+/- 0.09) cm compared with the healthy volunteers (p < 0.001). PS-distances of up to 0.51 (+/- 0.15) cm were found only in symptomatic climbers and proved to be a sign of tendon bow-stringing. No impairment of gliding ability was seen in both groups. Tendon sheath cysts were detected in 76% (62) of symptomatic fingers of the climbers. CONCLUSIONS: Non-invasive high-resolution ultrasound examination of fingers proved to be a very helpful method for diagnosing changes due to strain as well as finger injuries in rock climbers, especially in cases where the clinical examination was difficult to perform.
Diagnostic quality in endoscopic retrograde cholangiopancreatography: comparison between lodixanol and lopromide.
BACKGROUND AND STUDY AIMS: The contrast medium for endoscopic retrograde cholangiopancreatography (ERCP) must produce adequate images, whilst keeping the risk of complications to a minimum. There is a theoretical reason to suppose that a dimeric isosmolar medium may be superior to a monomeric hyperosmolar medium. We have compared two such media in a triple-centre double-blind randomized study on patients referred with a clinical indication for ERCP. PATIENTS AND METHODS: A total of 160 patients were randomly allocated to either lodixanol or lopromide. Assessments were made of the quality of images and the complications encountered. RESULTS: A total of 151 patients were evaluated. Apart from a trend towards better diagnostic quality for main pancreatic duct imaging with lodixanol, there were no differences between the two groups. The overall frequencies of adverse events were similar CONCLUSIONS: lodixanol is a safe and effective water-soluble contrast medium for ERCP, comparable to lopromide, but despite theoretical advantages lodixanol has no clear practical benefit.