[Update: clinical imaging of cartilage-part 1 : Technical aspects]. / Update: Klinische Knorpelbildgebung ­ Teil 1 : Technische Aspekte.

BACKGROUND: In order to answer clinical therapy-oriented questions, reliable and consistent depiction of articular cartilage across technical platforms is necessary. MATERIALS AND METHODS: Technical standards and developments in cartilage imaging are summarized based on current literature and experience from clinical daily routine. RESULTS: Clinical questions that need to be answered relate to cross-sectional extent, depth, differentiating cartilaginous from bony components of a lesion and to the lesion's location within the compartment. If present, displaced fragments, concomitant meniscal, ligamentous and/or degenerative lesions should be identified. To date, magnetic resonance imaging (MRI) is the workhorse of cartilage imaging and is largely based on moderately T2-weighted and also proton-density (PD)-weighted fat-suppressed turbo-spin-echo sequences. Direct MR- and CT-arthrography are the gold standard to evaluate thin cartilage layers. Recent advances in coil and MR sequence design, increased availability of 3T-MR scanners and more and more sophisticated acceleration techniques allow for better spatial resolution and more robust image contrast at acceptable scan times. DISCUSSION: As abundant as current developments in clinical routine cartilage imaging may be, the radiologist must carefully select the approach best suited to answering the clinical questions.

[Update: Clinical imaging of cartilage-part 2 : Aspects helpul in daily clinical practice]. / Update: Klinische Knorpelbildgebung ­ Teil 2 : In der Klinik hilfreiche Aspekte.

BACKGROUND: Imaging-based analysis of articular cartilage and its defects as well as the radiologist have to live up to the more and more specific clinical questions arising from increasing experience with cartilage-dedicated therapies. MATERIALS AND METHODS: Based on the currently available literature and experience from clinical routine, imaging findings relevant for lesion analysis will be summarized and illustrated by specific pathologies. RESULTS: Local aspects and topographic distribution of bone marrow edema pattern (BMEP), careful analysis of the cartilage surface and of the subchondral plate as well as the patient's clinical and biomechanical context are essential for image analysis. Formal grading is helpful to communicate imaging findings, but in itself is not sufficient for a comprehensive analysis. Assessing the stability of a lesion is important for therapy planning. Imaging is helpful to this end, but can be challenging and requires consideration of the arthroscopic and histologic perspective especially when dealing with juvenile osteochondral lesions. DISCUSSION: In order to maximize the therapeutic and prognostic relevance of findings from cartilage imaging, radiologists need to be sensitive to-often very subtle-imaging clues but at the same time we need to be aware of the limitations of our methods.

[IL-1-blockade with Anakinra during pregnancy : Retrospective analysis of efficacy and safety in female patients with familial Mediterranean fever]. / IL-1-Blockade mit Anakinra in der Schwangerschaft : Retrospektive Wirksamkeits- und Sicherheitsanalyse bei Patientinnen mit familiärem Mittelmeerfieber.

OBJECTIVE: To retrospectively assess and analyze the clinical efficacy and safety of off-label interleukin-1 (IL-1) blockade with anakinra during pregnancy of patients with familial Mediterranean fever (FMF). METHODS: Retrospective analysis of clinical and laboratory parameters making use of an electronic database system. Detailed descriptions of the genotype and phenotype of FMF are given and the course of the pregnancy and fetal development are reported. RESULTS: The data of three patients and a total of four pregnancies under treatedment with anakinra were analyzed. All patients were of Mediterranean origin, fulfilled the Tel Hashomer criteria for diagnosis of FMF and had a confirmed mutation in the MEFV gene. In all patients, treatment with anakinra was initiated due to an insufficient treatment response to colchicine. Anakinra led to a rapid response in all patients. In three pregnancies anakinra treatment was continued during the whole pregnancy, while in one pregnancy anakinra was started in the second trimester because of uncontrolled FMF activity. Fetal development was normal in all pregnancies. In two patients the fetuses were carried to term, while in one patient a primary cesarean section was carried out in week 33 because of an increased risk for complications. All children showed an unremarkable early childhood development without any signs of an existing disease. CONCLUSION: The data of our retrospective analysis suggest that IL-1-blockade by anakinra is an effective and safe treatment in pregnant women suffering from FMF, which can reliably prevent disease flares. In the four pregnancies presented the use of anakinra did not result in impaired fetal and (early) childhood development.

Hospital-based enhanced surveillance for West Nile virus neuroinvasive disease.

Accurate data on the incidence of West Nile virus (WNV) disease are important for directing public health education and control activities. The objective of this project was to assess the underdiagnosis of WNV neuroinvasive disease through laboratory testing of patients with suspected viral meningitis or encephalitis at selected hospitals serving WNV-endemic regions in three states. Of the 279 patients with cerebrospinal fluid (CSF) specimens tested for WNV immunoglobulin M (IgM) antibodies, 258 (92%) were negative, 19 (7%) were positive, and two (1%) had equivocal results. Overall, 63% (12/19) of patients with WNV IgM-positive CSF had WNV IgM testing ordered by their attending physician. Seven (37%) cases would not have been identified as probable WNV infections without the further testing conducted through this project. These findings indicate that over a third of WNV infections in patients with clinically compatible neurological illness might be undiagnosed due to either lack of testing or inappropriate testing, leading to substantial underestimates of WNV neuroinvasive disease burden. Efforts should be made to educate healthcare providers and laboratorians about the local epidemiology of arboviral diseases and the optimal tests to be used in different clinical situations.

Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T.

OBJECTIVES: To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures. METHODS: Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments. RESULTS: Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals. CONCLUSIONS: Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities. KEY POINTS: • 3D MRI helps differentiate true knee-cartilage deformation from random measurement error • 3D MRI maps depict in vivo topographic distribution of cartilage deformation after loading • 3D MRI maps depict in vivo intensity of cartilage deformation after loading • Locating cartilage contact areas might aid differentiating common and work-related osteoarthritis.

Primary wound closure with a Limberg flap vs. secondary wound healing after excision of a pilonidal sinus: a multicentre randomised controlled study.

PURPOSE: Off-midline procedures seem to be the best method of primary wound closure after excision of a pilonidal sinus. Primary wound closure with a Limberg flap was compared to secondary wound healing. METHODS: From January 2006 to July 2012, 102 patients with given informed consent (mean age 28 years, men 81%) who had excision of a pilonidal sinus in three hospitals in Switzerland were randomised to group L (Limberg flap, n = 51) or to group E (excision only, n = 51). Primary endpoint was duration of incapacity for work. Follow-up was at 3 weeks and at 1 year postoperative (95% follow-up). RESULTS: Both groups were comparable with regard to patient characteristics. The median (range) operation time was 60 (30-80) min in group L vs. 30 (10-75) min in group E (p < 0.001). No significant differences were found in postoperative pain and painkiller intake; pain, percentage of patients at work and overall satisfaction at 3 weeks postoperative; and overall duration of incapacity for work and overall satisfaction at 1-year follow-up. The complication rate was 49% in group L vs. 12% in group E (p < 0.001). Complications in group L were seroma (6%), wound dehiscence (45%), skin necrosis (10%), hematoma (6%), infection (4%) and recurrent disease (13%). Complications in group E were recurrent disease (6%) and wound healing disorder (6%). CONCLUSIONS: After excision of a pilonidal sinus, primary wound closure with a Limberg flap has no advantage over secondary wound healing. The main reason for this conclusion is the relatively high complication rate of primary wound closure with a Limberg flap.

Treatment of rare co-occurrence of Epstein-Barr virus-driven post-transplant lymphoproliferative disorder and hemophagocytic lymphohistiocytosis after allogeneic stem cell transplantation.

In both conditions, post-transplant lymphoproliferative disorder (PTLD) and hemophagocytic lymphohistiocytosis (HLH), infection with Epstein-Barr virus (EBV) is a key mechanism: almost all PTLD in allogeneic stem cell transplantation (alloSCT) is caused by EBV-related neoplastic lymphoproliferation, and secondary HLH is most frequently triggered by EBV infection. Therefore, concomitant EBV-driven PTLD and HLH early after alloSCT require an approach to eliminate EBV and balance immune activation simultaneously. We report on a patient who developed simultaneous PTLD and signs of HLH on day 64 after alloSCT. Treatment was comprised of stopping cyclosporine, short-course dexamethasone, and 3 courses of rituximab. The patient showed full recovery and complete remission of lymphadenopathy. This result indicates that immediate reduction in EBV-carrying B cells by rituximab, suppression of general inflammation, and parallel support of reconstitution of long-term T-cell function, might be an appropriate therapeutic approach in this rare situation.

[Post-treatment rehabilitation after autologous chondrocyte implantation: State of the art and recommendations of the Clinical Tissue Regeneration Study Group of the German Society for Accident Surgery and the German Society for Orthopedics and Orthopedic Surgery]. / Nachbehandlung bei der autologen Chondrozytentransplantation: Eine Bestandsaufnahme und Empfehlung der AG Klinische Geweberegeneration der DGU/DGOOC.

BACKGROUND: Over the course of the past two decades autologous chondrocyte implantation (ACI) has become an important surgical technique for treating large cartilage defects. The original method using a periostal flap has been improved by using cell-seeded scaffolds for implantation, the matrix-based autologous chondrocyte implantation (mb-ACI) procedure. MATERIAL AND METHODS: Uniform nationwide guidelines for post-ACI rehabilitation do not exist. A survey was conducted among the members of the clinical tissue regeneration study group concerning the current rehabilitation protocols and the members of the study group published recommendations for postoperative rehabilitation and treatment after ACI based on the results of this survey. RESULTS: There was agreement on fundamentals concerning a location-specific rehabilitation protocol (femoral condyle vs. patellofemoral joint). With regard to weight bearing and range of motion a variety of different protocols exist. Similar to this total agreement on the role of magnetic resonance imaging (MRI) for postsurgical care was found but again a great variety of different protocols exist. CONCLUSIONS: This manuscript summarizes the recommendations of the members of the German clinical tissue regeneration study group on postsurgical rehabilitation and MRI assessment after ACI (level IVb/EBM).

Encephalitis with thalamic and basal ganglia abnormalities: etiologies, neuroimaging, and potential role of respiratory viruses.

BACKGROUND: Encephalitis is a severe neurological syndrome with devastating consequences. Despite extensive testing, the etiology often remains unknown. Involvement of the thalamus or basal ganglia (T/BG) occurs in a subset of patients with encephalitis and may be an important etiological clue. In order to improve diagnosis of T/BG patients, we reviewed this subgroup within the California Encephalitis Project (CEP). METHODS: Data from T/BG cases enrolled in CEP were retrospectively reviewed. Cases were stratified by age and grouped by etiological classification: infectious, postinfectious, and noninfectious. Neuroimaging reports were examined and compared between etiologies. RESULTS: T/BG neuroimaging abnormalities were reported in 6% of 3236 CEP cases. An etiology was found in 76%: 37% infectious, 16% postinfectious, and 23% noninfectious. The most frequently identified infectious agents were respiratory viruses, accounting for 31%, predominantly in children. Other infections more common in the T/BG group included Creutzfeldt-Jakob disease, arbovirus, and Mycobacterium tuberculosis. Infectious and postinfectious cases had higher median cerebrospinal fluid white blood cell count than noninfectious etiologies. Notably, T/BG neuroimaging characteristics were associated with distinct etiologies. In particular, symmetric hemorrhagic abnormalities involving the thalamus were most frequently found within the respiratory virus group. CONCLUSIONS: T/BG involvement in patients with suspected encephalitis was associated with specific etiologies. In addition to agents with established predilection for the T/BG such as M. tuberculosis and arboviruses, a surprisingly high number of cases were associated with respiratory viruses, especially in children. Neuroimaging abnormalities in such patients can aid clinicians in narrowing the etiological scope and in guiding testing.

Case definitions, diagnostic algorithms, and priorities in encephalitis: consensus statement of the international encephalitis consortium.

BACKGROUND: Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research. METHODS: In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study. RESULTS: We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed. CONCLUSIONS: We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

A new method to analyze dGEMRIC measurements in femoroacetabular impingement: preliminary validation against arthroscopic findings.

OBJECTIVE: To validate a new method to analyze delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) measurements in the hip for early assessment of cartilage defects in femoroacetabular impingement (FAI). METHODS: We performed a retrospective review of 10 hips in 10 FAI patients, who underwent hip arthroscopy. T1-weighted images and dGEMRIC T(1) maps were acquired at 1.5 T on coronal planes, including the anterior-superior, superior, posterior-superior hip cartilage. For all slices, a region of interest (ROI) was defined over the central portion of the femoral cartilage, assumed to be healthy, and T1 values (x) were transformed to standard scores (z) using z = (x -µ)/σ, where µ and σ are the average and standard deviation of T1 in the femoral ROI. Diagnostic performance of the resulting standardized dGEMRIC maps was evaluated against intraoperative findings and compared with that of a previously proposed dGEMRIC analysis as well as morphologic assessment. RESULTS: Assuming z = -2 or z = -3 as the threshold between normal and degenerated cartilage, sensitivity, specificity and accuracy were 88%, 51% and 62%, and 71%, 63% and 65%, respectively. By using T1 = 500 ms as single threshold for all dGEMRIC T1 maps, these values became 47%, 58% and 55%, whereas they were 47%, 79% and 70% for morphologic evaluation. CONCLUSIONS: Standardized dGEMRIC can increase the sensitivity in detecting abnormal cartilage in FAI and has the potential to improve the clinical interpretation of dGEMRIC measurements in FAI, by removing the effect of inter- and intra-patient T1 variability.

A simplified approach for computed tomography with an X-ray grating interferometer.

We present a simplified acquisition and processing method for X-ray grating interferometry computed tomography (CT). The proposed approach eliminates the need to scan the gratings, thus allowing for a faster CT acquisition compared to methods presently in use. The contrast in the reconstructed images can be expressed as a linear combination of the absorption and refraction within the sample. Experimental images of a test phantom made of known materials and a human bone-cartilage sample prove the correctness of the method and show very good agreement with the theory. The here proposed approach might be highly interesting in many fields where a reduced imaging acquisition time is requested and/or where the radiation dose delivered to the sample has to be kept low, such as, for example, in in-vivo imaging.

Development and validation of a new method for the radiologic measurement of the tibial slope.

PURPOSE: The posterior tibial slope has a huge influence on the kinematics of the knee. In several orthopedic interventions such as high tibial osteotomy and unicondylar or bicondylar knee replacement changing, the tibial slope can result in altered knee mechanics. Therefore, an exact preoperative measurement of the posterior tibial slope is mandatory. Several methods are used on conventional radiographs and CT scans, but until now there is no standard validated method. The aim of this study was to compare several methods and imaging techniques to measure the posterior tibial slope and to establish a standard and reliable measurement method by radiography. METHODS: Fourteen knees (seven cadavers) were scanned by a 64-slice CT, a 3T-MRI, and true lateral radiographs were performed. The anatomical references (TPAA = tibial proximal anatomical axis; ATC = anterior tibial cortex; PTC = posterior tibial cortex) and the new computed reference (MPA = mean of PTA and ATC) were compared by short as well as long radiographs, CT scan and MRI. The influence of a malrotation in radiographs of the knees was also analyzed. RESULTS: CT scan and MRI are suitable for the measurement of the medial and lateral posterior tibial slopes, the results of the radiographs varied depending on the method used. The new method (MPA) showed the best correlation to the CT scan (r = 0.997), even on short radiographs (10 cm distal the joint line). CONCLUSION: The measurement of the posterior tibial slope on a short lateral radiograph using the MPA is a reliable method and should be established as a standard. LEVEL OF EVIDENCE: Diagnostic study, Level II.

The del/del genotype of the nuclear factor-kappaB -94ATTG polymorphism and its relation to aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Periodontitis is influenced by specific host-dependent immune responses. Periodontopathogens induce innate immune responses, amongst others, via toll-like receptor 2 (TLR2), resulting in activation of the nuclear transcription factor nuclear factor-kappaB (NF-kappaB). The aim of this case-control study was to evaluate links between genetic variants of these genes and chronic/aggressive periodontitis in a multivariate model. MATERIAL AND METHODS: A total of 141 patients with periodontitis (63 with chronic periodontitis and 78 with aggressive periodontitis) and 81 controls without periodontitis were included in the study. Polymorphisms in TLR2 (Arg677Trp, Arg753Gln) and in NF-kappaB (-94ins/delATTG) were determined by restriction fragment length polymorphism and fragment length analyses, respectively. Subgingival bacterial colonization was evaluated using a PCR/DNA probe test (micro-Ident). RESULTS: Although there was no association of the TLR2 polymorphism Arg753Gln with periodontitis, heterozygous carriers (Arg/Gln) were at a higher risk for colonization with bacteria of the 'red complex' (corrected p-value = 0.042). The del/del genotype of the NF-kappaB polymorphism was associated with aggressive periodontitis considering age, gender, smoking and approximal plaque index as potential confounders (odds ratio = 2.81, p = 0.035, 95% confidence interval: 1.08-7.33). del/del carriers had a higher risk for subgingival colonization with Aggregatibacter actinomycetemcomitans (odds ratio = 2.36, p = 0.030, 95% confidence interval: 1.09-5.1; adjusted for age, gender, smoking and pocket depth(bacteria)). CONCLUSIONS: The del/del genotype of NF-kappaB was shown to be associated with the occurrence of aggressive periodontitis.

Primary structure of neocarzinostatin, an antitumor protein.

The antitumor protein neocarzinostatin is an acidic single-chain molecule, cross-linked by two disulfide bridges, and consists of 109 amino acid residues. Complete disulfide bond reduction and S-carboxymethylation was achieved in liquid ammonia. Sequence determination of five tryptic fragments led to the proposed primary structure.

Anti-NMDA receptor encephalitis: report of ten cases and comparison with viral encephalitis.

The California Encephalitis Project (CEP), established in 1998 to explore encephalitic etiologies, has identified patients with N-methyl-D-aspartate receptor (NMDAR) antibodies, the likely etiology of their encephalitis. This study compares the presentation of such patients to those with viral encephalitis, so that infectious disease clinicians may identify individuals with this treatable disorder. Patients were physician-referred, and standardized forms were used to gather demographic, clinical, and laboratory data. Features of anti-NMDAR+ patients were compared with the viral encephalitides of enteroviral (EV), rabies, and herpes simplex-1 (HSV-1) origins. Sixteen cases with confirmed viral etiologies were all negative on NMDAR antibody testing. Ten anti-NMDAR+ patients were profiled with a median age of 18.5 years (range 11-31 years). None were Caucasian. They had a characteristic progression with prominent psychiatric symptoms, autonomic instability, significant neurologic abnormalities, and seizures. Two had a teratoma, and, of the remaining eight, four had serologic evidence of acute Mycoplasma infection. The clinical and imaging features of anti-NMDAR+ patients served to differentiate this autoimmune disorder from HSV-1, EV, and rabies. Unlike classic paraneoplastic encephalitis, anti-NMDAR encephalitis affects younger patients and is often treatable. The association of NMDAR antibodies in patients with possible Mycoplasma pneumoniae infection warrants further study.

Interleukin-2 -330 and 166 gene polymorphisms in relation to aggressive or chronic periodontitis and the presence of periodontopathic bacteria.

BACKGROUND AND OBJECTIVE: As a pro-inflammatory cytokine, interleukin-2 mediates the activation, growth and differentiation of T and B lymphocytes and natural killer cells. Promoter polymorphisms of the interleukin-2 gene have been associated with altered interleukin-2 production or identified as prognostic markers for various infectious diseases. Therefore, the aim of this study was to evaluate two polymorphisms at positions -330 T/G and 166 G/T in patients with generalized chronic periodontitis (n = 58) or generalized aggressive periodontitis (n = 73) in comparison with periodontitis-free controls (n = 69). MATERIAL AND METHODS: Both interleukin-2 polymorphisms were analyzed using the polymerase chain reaction with sequence-specific primers. Distributions of single alleles, genotypes and haplotypes were calculated using the chi-square test. Risk factor analyses were carried out by logistic regression with respect to established cofactors for periodontitis. The presence of subgingival bacteria in an individual were analyzed using a molecular biological method (the micro-Ident test). RESULTS: The interleukin-2 genotype -330 TG occurred less frequently in patients with chronic periodontitis (25.9% vs. 49.3%). Moreover, this genotype decreased the adjusted odds ratio for chronic periodontitis (odds ratio = 0.394), whereas the interleukin-2 genotype 166 TT and the haplotype combination interleukin-2 -330,166 TT : TT were associated with an increased adjusted odds ratio (odds ratio = 2.82 or 2.97). For the latter interleukin-2 combination, a positive association for the subgingival presence of Porphyromonas gingivalis (81.3% vs. 59.5%) and bacteria of the 'red complex' (78.1% vs. 56.0%) was shown. CONCLUSION: The interleukin-2 genotypes -330 TG and 166 TT, as well as the combination genotype interleukin-2 TT : TT, could be putative prognostic factors for chronic periodontitis.

The interleukin-10 promoter haplotype ATA is a putative risk factor for aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Interleukin-10 has been described as an anti-inflammatory cytokine and a B-cell proliferation factor. Promoter polymorphisms of the interleukin-10 gene have been associated with altered interleukin-10 expression. Therefore, the aim of this study was to evaluate three polymorphisms at positions -1082G>A, -819C>T and -590C>A in patients with generalized chronic periodontitis (n = 27) and generalized aggressive periodontitis (n = 32) in comparison with periodontitis-free controls (n = 34). MATERIAL AND METHODS: Interleukin-10 promoter polymorphisms were analyzed by polymerase chain reaction with sequence-specific primers (PCR-SSP). Distributions of single alleles, genotypes and haplotypes were calculated by the chi-square test. Risk factor analyses were carried out by logistic regression. Subgingival bacteria were subjected to molecular biological analyses using the micro-Ident test. RESULTS: The combination ATA/ATA was found only in patients with aggressive periodontitis (15.6 vs. 0.0%, p = 0.023). Taking into account age, gender, smoking and plaque level, an increased odds ratio (3.7, p = 0.04) for aggressive periodontitis was shown for subjects with the haplotype ATA. Prevotella intermedia was found to be decreased in ACC- positive (41.3 vs. 66.7%, p = 0.022), ATA-positive (33.3 vs. 57.1%, p = 0.032) and ACC/ATA-positive (20.0 vs. 55.9%, p = 0.002) individuals. In GCC/GCC-positive subjects, P. intermedia occurred more frequently (86.7 vs. 42.3%, p = 0.002). CONCLUSION: The haplotype ATA, which is known as a 'low interleukin-10 producer' is a putative risk indicator for generalized aggressive periodontitis.

MR-based semi-automated quantification of renal functional parameters with a two-compartment model--an interobserver analysis.

PURPOSE: To assess the interobserver agreement in a semi-automated quantification approach of MR-renal perfusion and filtration parameters with a two-compartment model analysis. MATERIALS AND METHODS: Twelve consecutive patients underwent renal perfusion measurements after intravenous injection of 7 ml Gd-BOPTA at 4 ml/s at 3.0 T. Two independent observers placed two regions of interest (ROI) manually on the axial slice, one in the abdominal aorta to determine the arterial input function (AIF), and one at the tissue-air interface for retrospective triggering. The data were fitted on a pixel-by-pixel basis to the two-compartment model, producing maps of the perfusion parameters FP (plasma flow), TP (plasma mean transit time) and of the tubular filtration parameters FT (tubular flow) and TT (tubular mean transit time). A cortical ROI was segmented by selecting those pixels with plasma volume VP>10 ml/100 ml, and the model fit was repeated on a ROI basis to produce the cortical averages. RESULTS: The average values (observer 1/observer 2) were FP (226.2/187.3 ml/100 ml/min), TP (9.0/9.1s), FT (23.5/20.8 ml/100 ml/min), TT (142.1/140.0 s). The correlation coefficients between both observers were 0.90 (FP), 0.80 (TP), 0.80 (FT), 0.78 (TT). Correlations of all values were significant (p<0.05). A paired t-test yielded significant differences for FP (p=0.004). DISCUSSION/CONCLUSION: The data demonstrate a significant systematic difference for the parameter FP, while TP seems to be most stable. Further decrease of the residual variability of all parameters seems desirable to improve the robustness of the method for clinical routine.

Impact of genetic variants of CD14 and TLR4 on subgingival periodontopathogens.

CD14 and toll-like receptor 4 (TLR4) are involved in host's immune response to bacterial pathogens including periodontal bacteria. Functional important gene polymorphisms are described for both genes. The aim of this study was to evaluate links between genetic polymorphisms of CD14 and TLR4 and risk markers of periodontitis in a multivariate model. One hundred and thirty-three periodontitis patients (chronic: n = 60, aggressive: n = 73) and 80 healthy controls without periodontitis were included in the study. Polymorphisms in CD14 c.-159C>T and in TLR4 Asp299Gly, Thr399Ile were determined by restriction fragment length polymorphism analyses. The clinical investigation included smoking status, plaque and bleeding indexes, pocket depth and attachment loss. Subgingival bacterial colonization was analysed molecularbiologically using the micro-Ident test. Prevotella intermedia occurred less frequently in individuals positive for the TT genotype of CD14 in bivariate analysis (odds ratio = 0.36%, confidence interval: 0.14-0.91, P = 0.045). In binary logistic regression analyses, the occurrence of this bacterium was significantly decreased in TT carriers (odds ratio = 0.31%, confidence interval: 0.81-0.12, P = 0.017) considering age, smoking and maximum clinical attachment loss at microbial test site as confounding factors. However, no significant association with chronic and or aggressive periodontitis and polymorphisms in CD14 and TLR4 could be proven. Although the CD14 c.-159C>T polymorphism could be shown to be associated with subgingival colonization with P. intermedia, there is no evidence that CD14 and TLR4 polymorphisms investigated are independent risk factors for chronic or aggressive periodontitis in German periodontitis patients.