Medizin - Open Access LMU - Teil 14/22 Archiv
250 Episoden
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Background: Total tau (T-tau) and beta-amyloid((1-42)) (A beta(1-42)) levels in cerebrospinal fluid (CSF) can differentiate Alzheimer's disease (AD) from normal aging or depressive pseudo-dementia. Differential diagnosis from dementia with Lewy bodies (DLB) in clinical settings is difficult. Methods: The analytical performance of the INNOTEST (R) PHOSPHO-TAU((181P)) assay was validated in terms of selectivity, sensitivity, specificity, precision, robustness, and stability. Clinical utility of the assay alone, or combined with T-tau and AP1-421 for discrimination of AD (n=94) from patients suffering from DLB (n=60) or from age-matched control subjects (CS) (n=60) was assessed in a multicenter study. Results: CSF concentrations of tau phosphorylated at threonine 181 (P-tau(181P)) in AD was significantly higher than in DLB and CS. Discriminant analysis, a classification tree, and logistic regression showed that P-tau(181P) was the most statistically significant single variable of the three biomarkers for discrimination between AD and DLB. Conclusions: P-tau(181P) quantification is a robust and reliable assay that may be useful in discriminating AD from DLB.
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Background: Measurement of late-night salivary cortisol concentrations is increasingly used as a screening test in suspected Cushing's syndrome. Cortisol concentrations are typically extremely low in late-night samples and discordant assay-specific reference ranges have been reported. Therefore, the aim of our study was to assess the analytical performance of the first automated cortisol immunoassay specified for salivary measurements and to establish late-night sampling reference-range data for this test. Methods: Salivary cortisol was measured using the Roche Cobas Cortisol assay (Roche Diagnostics). Five salivary pools in different concentration ranges were used to assess the inter-assay imprecision of this test in a two-centre evaluation protocol including two reagent lots. Linearity was tested by serial dilution. Salivary samples were obtained at 23:00 h from 100 apparently healthy volunteers using a commercially available salivary sampling device (Salivette, Sarstedt). A subset of 20 samples was used for method comparison with isotope dilution liquid chromatography-tandem mass spectrometry. Results: Inter-assay coefficients of variation (n=20) between 11.6% and 40.4% were found for mean cortisol concentrations between 12.9 and 2.6 nmol/L, with an estimated functional sensitivity of approximately 5.0 nmol/L. The test also gave linear results in the lowest concentration range between 1.0 and 8.3 nmol/L. Mean late-night salivary cortisol of 5.0 nmol/L was found for healthy individuals; the absolute range was 1.4-16.7 nmol/L, and the 95th percentile was 8.9 nmol/L. Substantially lower concentrations were found with isotope dilution LC-MS/MS compared to immunoassay results (mean concentrations 1.8 and 4.4 nmol/L, respectively). Conclusions: The automated assay investigated was found to offer acceptable analytical performance in the very low concentration range required for late-night salivary cortisol, despite a very short turnaround time. Using this assay, late-night salivary cortisol concentrations below 8.9 nmol/L are typically found in healthy volunteers.
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Aims: The decrease in uterine resistance during normal pregnancy is known to be related to invading trophoblast cells which derive from placental tissue. Uterine and peripheral resistance is elevated in preeclampsia. The aim of the present study was to prospectively examine uterine and peripheral resistance in pregnancies complicated by preeclampsia (PE), fetal intrauterine growth restriction (IUGR) and pregnancy induced hypertension (PIH). Methods: Sixty-seven women with normal pregnancies, 17 with PE, 12 with IUGR underwent Doppler sonographic investigation of the uterine and the cubital arteries. The Pulsatility Index (PI) was calculated for each vessel. Statistical analysis was performed and a P-value < 0.05 was considered significant. Results: Patients with preeclampsia and IUGR showed a significant higher resistance at the placental (mean PI 1.267 and 1.063), nonplacental (mean PI 1.631 and 1.124) and cubital artery (mean PI 3,777 and 3.995) compared to the normal pregnancy group (mean PI 0.678; 0.859 and 2.95 respectively). Mean birth weight in the PE group was 1409 g, in the IUGR group 1649 g and 3419 g in the normal pregnancy group. Conclusions: Pregnancies with IUGR are associated with elevated peripheral resistance in the maternal arterial system as seen in pregnancies with preeclampsia. Our findings encourage to further investigate the maternal vascular system in high risk pregnancies.
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Background: Endogenous ligands of cannabinoid receptors ( endocannabinoids), in particular anandamide ( arachidonylethanolamide), have been recognized as being of crucial importance in a variety of physiological functions. Plasma concentrations of anandamide have been measured in a number of investigations; however, discrepant data on "normal'' anandamide plasma concentrations were reported. Since this might be caused by pre-analytical variables, we investigated the impact of different sample handling conditions on measured plasma anandamide concentrations. Methods: Blood samples were taken from healthy volunteers in EDTA- or heparin-containing tubes; whole blood samples were kept at +4 degrees C, room temperature, or 37 degrees C, respectively, for up to 120 min before obtaining plasma by centrifugation. Plasma anandamide concentrations were measured by an isotope-dilution liquid chromatography tandem mass spectrometry ( LC-MS/MS) method. Results: A marked time- and temperature-dependent increase in plasma anandamide concentrations ex vivo was observed in both EDTA- and heparin-containing tubes. Mean anandamide concentrations approximately doubled when EDTA samples were kept at 4 degrees C for 60 min before centrifugation {[}immediately centrifuged, 1.3 mg/L ( SD 0.3 mg/L); 2.8 mg/L ( SD 0.5 mg/L) after storage for 60 min; n=12). After storage of heparinized whole-blood samples for 120 min at 37 degrees C, a mean plasma anandamide concentration of 11.9 mg/L ( SD 1.8 mg/L) was found. In cell-free plasma, no increase in anandamide concentrations was found. Conclusion: Anandamide is released from blood cells ex vivo at a very high rate; therefore, strictly standardized pre-analytical protocols have to be applied for plasma anandamide determination.
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Background: Type 2 diabetes mellitus is associated with increased cardiovascular risk. One laboratory marker for cardiovascular risk assessment is high-sensitivity C-reactive protein (hsCRP). Methods: This cross-sectional study attempted to analyze the association of hsCRP levels with insulin resistance, beta-cell dysfunction and macrovascular disease in 4270 non-insulin-treated patients with type 2 diabetes {[}2146 male, 2124 female; mean age +/- SD, 63.9 +/- 11.1 years; body mass index (BMI) 30.1 +/- 5.5 kg/m(2); disease duration 5.4 +/- 5.6 years; hemoglobin A(1c) (HbA(1c)) 6.8 +/- 1.3% ]. It consisted of a single morning visit with collection of a fasting blood sample. Observational parameters included several clinical scores and laboratory biomarkers. Results: Stratification into cardiovascular risk groups according to hsCRP levels revealed that 934 patients had low risk (hsCRP < 1 mg/L), 1369 patients had intermediate risk (hsCRP 1-3 mg/L), 1352 patients had high risk (hsCRP > 3-10 mg/ L), and 610 patients had unspecific hsCRP elevation ( > 10 mg/ L). Increased hsCRP levels were associated with other indicators of diabetes-related cardiovascular risk (homeostatic model assessment, intact proinsulin, insulin, BMI, beta-cell dysfunction, all p < 0.001), but showed no correlation with disease duration or glucose control. The majority of the patients were treated with diet (34.1%; hsCRP levels 2.85 +/- 2.39 mg/L) or metformin monotherapy (21.1%; 2.95 +/- 2.50 mg/L hsCRP). The highest hsCRP levels were observed in patients treated with sulfonylurea (17.0%; 3.00 +/- 2.43 mg/ L). Conclusions: Our results indicate that hsCRP may be used as a cardiovascular risk marker in patients with type 2 diabetes mellitus and should be evaluated in further prospective studies.
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Background: The neuroprotein S100 released into the circulation has been suggested as a reliable marker for primary brain damage. However, safe identification of relevant traumatic brain injury (TBI) may possibly be hampered by S100 release from peripheral tissue. The objective of this study was to measure early S100 levels using the Elecsys((R)) S100 immunoassay for real-time assessment of severe TBI in multiple trauma. Methods: Consecutively admitted multiple trauma patients (injury severity score >= 16 points) were stratified according to the results of the initial cerebral computed tomography (CCT) examination. S100 serum levels were determined at admission and at 6, 12, 24, 48 and 72 h after trauma. Data were correlated to creatine phosphokinase (CK) and lactate dehydrogenase (LDH) serum levels. Using receiver operating characteristic (ROC) analysis, the discriminating power of S100 measurement was calculated for the detection of CCT+ findings. Results: Median S100 levels of CCT+ patients (n=9; 37 years) decreased from 3.30 mu g/L at admission to 0.41 mu g/L 72 h after trauma. They revealed no significant differences to CCT- patients (n=18; 44 years), but remained elevated compared to controls. Median CK and LDH levels correlated with the corresponding S100 levels during the first 24 h after trauma. ROC analysis displayed a maximum area under the curve of only 0.653 at 12 h after trauma. No significant difference was calculated for the differentiation between CCT+ and CCT- patients. Conclusions: Measurements of S100 serum levels using the Elecsys((R)) S100 immunoassay are not reliable for the real-time detection of severe TBI in multiple trauma patients. Due to soft tissue trauma or bone fractures, S100 is mainly released from peripheral sources such as adipocytes or skeletal muscle cells.
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Background: Liquid chromatography tandem-mass spectrometry (LC-MS/MS) is an efficient technology for routine determination of immunosuppressants in whole blood; however, time-consuming manual sample preparation remains a significant limitation of this technique. Methods: Using a commercially available robotic pipetting system (Tecan Freedom EVO), we developed an automated sample-preparation protocol for quantification of tacrolimus in whole blood by LC-MS/MS. Barcode reading, sample resuspension, transfer of whole blood aliquots into a deep-well plate, addition of internal standard solution, mixing, and protein precipitation by addition of an organic solvent is performed by the robotic system. After centrifugation of the plate, the deproteinized supernatants are submitted to on-line solid phase extraction, using column switching prior to LC-MS/MS analysis. The only manual actions within the entire process are decapping of the tubes, and transfer of the deep-well plate from the robotic system to a centrifuge and finally to the HPLC autosampler. Whole blood pools were used to assess the reproducibility of the entire analytical system for measuring tacrolimus concentrations. Results: A total coefficient of variation of 1.7% was found for the entire automated analytical process (n=40; mean tacrolimus concentration, 5.3 mu g/L). Close agreement between tacrolimus results obtained after manual and automated sample preparation was observed. Conclusions: The analytical system described here, comprising automated protein precipitation, on-line solid phase extraction and LC-MS/MS analysis, is convenient and precise, and minimizes hands-on time and the risk of mistakes in the quantification of whole blood immunosuppressant concentrations compared to conventional methods.
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Trastuzumab (Herceptin (R)) is a humanized monoclonal antibody that specifically targets HER2/neu (human epidermal growth factor receptor-2) breast cancer cells, which are overexpressed in about 25-30% of breast carcinomas. After phase I and II trials, several phase III studies of trastuzumab alone or in combination with various chemotherapies were conducted. Patients with HER2/neu overexpression levels of 3+ determined by immunohistochemical assay or gene amplification (fluorescence in situ hybridization) derive most clinical benefit from trastuzumab. Taking into consideration efficacy and side effect profile, the combination of trastuzumab and paclitaxel showed an improvement of all clinical parameters, including overall survival, for the first time in the history of palliative breast cancer therapy. The application of trastuzumab has meanwhile become an established part of systemic therapy of metastastic breast cancer, and excellent data of its application in the adjuvant setting now exist (NSABP-B31, NCCTG-N9831, HERA), with significantly better relapse-free survival in the treatment arms with trastuzumab. Ongoing trials investigate the role of trastuzumab in the neoadjuvant setting. Trastuzumab is generally well tolerated. Cardiotoxicity is the main concern, thus monitoring of cardiac function is recommended.
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Human epidermal growth factor receptor 2 (HER2) is overexpressed in 15-25% of breast cancers, usually as a result of HER2 gene amplification. Positive HER2 status is considered to be an adverse prognostic factor. Recognition of the role of HER2 in breast cancer growth has led to the development of anti-HER2 directed therapy, with the humanized monoclonal antibody trastuzumab (Herceptin (R)) having been approved for the therapy of HER2-positive metastatic breast cancer. Clinical studies have further suggested that HER2 status can provide important information regarding success or failure of certain hormonal therapies or chemotherapies. As a result of these developments, there has been increasing demand to perform HER2 testing on current and archived breast cancer specimens. This article reviews the molecular background of HER2 function, activation and inhibition as well as current opinions concerning its role in chemosensitivity and interaction with estrogen receptor biology. The different tissue-based assays used to detect HER2 amplification and overexpression are discussed with respect to their advantages and disadvantages, when to test (at initial diagnosis or pre-treatment), where to test (locally or centralized) and the need for quality assurance to ensure accurate and valid testing results.
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Background: International and national guidelines (S3 guideline) for the surveillance of post-treatment breast cancer patients recommend a clinical follow-up including routine history and physical examination and regular mammograms. The practice of a clinical follow-up has been often discussed, but has been proven not to be inferior when compared to an intensified follow-up in randomized trials. Patients and Methods: The present manuscript reports the patients' view on the basis of a survey including 2000 patients with a history of breast cancer. Results: A total of 452 patients (22.6%) answered the questionnaire. The median age was 62 years (range 23-85 years). More than 80% of the patients were disease-free at the time of the survey. The need for surveillance was affirmed by the majority of patients (>95%), and one third stated that there was a need for more technical efforts during follow-up. In contrast to the follow-up guidelines, the results of the present survey indicated that most of the regularly scheduled follow-up visits were expanded using extensive laboratory and imaging procedures. Conclusion: This survey shows that the majority of physicians obviously do not accept the present follow-up guidelines. A new surveillance study investigating the efficacy of an intensified surveillance based on the improved possibilities of modern diagnostics and endocrine, immunotherapeutic, chemotherapeutic and interventional treatment options is warranted.
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s Karyotypic evolution is a well-known phenomenon in patients with malignant hernatological disorders during disease progression. We describe a 50-year-old male patient who had originally presented with pancytopenia in October 1992. The diagnosis of a myelodysplastic syndrome (MDS) FAB subtype RAEB-t was established in April 1993 by histological bone marrow (BM) examination, and therapy with low-dose cytosine arabinoside was initiated. In a phase of partial hernatological remission, cytogenetic assessment in August 1993 revealed a ring chromosome 1 in 13 of 21 metaphases beside BM cells with normal karyotypes {[}46,XY,r(1)(p35q31)/46,XY]. One month later, the patient progressed to an acute myeloid leukemia (AML), subtype M4 with 40% BM blasts and cytogenetic examination showed clonal evolution by the appearance of additional numerical aberrations in addition to the ring chromosome{[}46,XY,r(1),+8,-21/45,XY,r(1),+8,-21,-22/46, XY]. Intensive chemotherapy and radiotherapy was applied to induce remission in preparation for allogeneic bone marrow transplantation (BMT) from the patient's HLA-compatible son. After BMT, complete remission was clinically, hematologically and cytogenetically (normal male karyotype) confirmed. A complete hematopoietic chimerism was demonstrated. A relapse in January 1997 was successfully treated using donor lymphocyte infusion and donor peripheral blood stem cells (PB-SC) in combination with GM-CSF as immunostimulating agent in April 1997, and the patient's clinical condition remained stable as of January 2005. This is an interesting case of a patient with AML secondary to MDS. With the ring chromosome 1 we also describe a rare cytogenetic abnormality that predicted the poor prognosis of the patient, but the patient could be cured by adoptive immunotherapy and the application of donor's PB-SC. This case confirms the value of cytogenetic analysis in characterizing the malignant clone in hernatological neoplasias, the importance of controlling the quality of an induced remission and of the detection of a progress of the disease. Copyright (c) 2006 S. Karger AG, Basel.
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Because of different measurement techniques and the easier design of the CRM prototype, this in vitro study aimed to compare the diagnostic performance and reproducibility of two electrical methods (Electronic Caries Monitor III, ECM and Cariometer 800, CRM) for occlusal caries detection, and to evaluate the effect of staining/ discoloration of fissures on diagnostic performance. Hundred and seventeen third molars with no apparent occlusal cavitation were selected. Six examiners inspected all specimens independently, using the CRM, and a subgroup of 4 using the ECM. Histological validation using a stereomicroscope was performed after hemisectioning. Intra- and interexaminer reproducibility was assessed by Lin's concordance correlation coefficient (CCC) and Bland and Altman analysis. Diagnostic performance parameters included sensitivity (SE), specificity (SP) and area under the ROC curve (A(z)). The CCC yielded an intra- and interexaminer reproducibility of 0.69/0.62 (ECM) and of 0.79/0.74 (CRM). The mean intra- and interexaminer 95% range of measurements (range between Bland and Altman limits of agreement) given in percentages of the instrument reading were 67%/65% for the ECM and 28%/33% for the CRM. A(z) at the D3-4 level was 0.74 (ECM) and 0.78 (CRM). The CRM showed at least equivalent diagnostic performance to the ECM. However, improvement is still desirable. Diagnostic performance appeared to be enhanced in discolored lesions; however, this may be related to sample lesion distribution characteristics. Copyright (C) 2006 S. Karger AG, Basel.
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Originally defined as a lymphokine inhibiting the random migration of macrophages, the macrophage migration inhibitory factor (MIF) is an important mediator of the host response to infection. Beyond its function as a classical cytokine, MIF is currently portrayed as a multifunctional protein with growth-regulating properties present in organ systems beyond immune cells. In previous studies, we detected substantial amounts of MIF in the rat epididymis and epididymal spermatozoa, where it appears to play a role during post-testicular sperm maturation and the acquisition of fertilization ability. To explore its presence in other species not yet examined in this respect, we extended the range of studies to the bull. Using a polyclonal antibody raised against MIF purified from bovine eye lenses, we detected MIF in the epithelium of the adult bovine epididymis with the basal cells representing a prominently stained cell type. A distinct accumulation of MIF at the apical cell pole of the epithelial cells and in membranous vesicles localized in the lumen of the epididynnal duct was obvious. In the fetal bovine epididymis, we also detected MIF in the epithelium, whereas MIF accumulation was evident at the apical cell surface and in apical protrusions. By immuno-electron microscopy of the adult bovine epididymis, we localized MIF in apical protrusions of the epithelial cells and in luminal membrane-bound vesicles that were found in close proximity to sperm cells. Although the precise origin of the MIF-containing vesicles remains to be delineated, our morphological observations support the hypothesis that they become detached from the apical surface of the epididymal epithelial cells. Additionally, an association of MIF with the outer dense fibers of luminal spermatozoa was demonstrated. Data obtained in this study suggest MIF release by an apocrine secretion mode in the bovine epididymis. Furthermore, MIF localized in the basal cells of the epithelium and in the connective tissue could be responsible for regulating the migration of macrophages in order to avoid contact of immune cells with spermatozoa that carry a wide range of potent antigens. Copyright (c) 2006 S. Karger AG, Basel.
