Objectives
To evaluate the diagnostic accuracy of multidetector CT (MDCT) for detection of lumbar disc herniation with MRI as standard of reference.
Methods
Patients with low back pain underwent ...indicated MDCT (128-row MDCT, helical pitch), 60 patients with iterative reconstruction (IR) and 67 patients with filtered back projection (FBP). Lumbar spine MRI (1.5 T) was performed within 1 month. Signal-to-noise ratios (SNR) of cerebrospinal fluid (CSF), annulus fibrosus (AF) and the spinal cord (SC) were determined for all modalities. Two readers independently rated image quality (IQ), diagnostic confidence and accuracy in the diagnosis of lumbar disc herniation using MRI as standard of reference. Inter-reader correlation was assessed with weighted κ.
Results
Sensitivity, specificity, precision and accuracy of MDCT for disc protrusion were 98.8%, 96.5%, 97.1%, 97.8% (disc level), 97.7%, 92.9%, 98.6%, 96.9% (patient level). SNR of IR was significantly higher than FBP. IQ was significantly better in IR owing to visually reduced noise and improved delineation of the discs. κ (>0.90) was excellent for both algorithms.
Conclusion
MDCT of the lumbar spine yields high diagnostic accuracy for detection of lumbar disc herniation. IR improves image quality so that the provided diagnostic accuracy is principally equivalent to MRI.
Key Points
•
MDCT is an accurate alternative to MRI in disc herniation diagnosis
.
•
By IR enhanced image quality improves MDCT diagnostic confidence similar to MRI
.
•
Advances in CT technology contribute to improved diagnostic performance in lumbar spine imaging
.
In humans, we reported an association of a certain allele of carnosinase gene with reduced carnosinase activity and absence of nephropathy in diabetic patients. CN1 degrades histidine dipeptides such ...as carnosine and anserine. Further, we and others showed that treatment with carnosine improves renal function and wound healing in diabetic mice and rats. We now investigated the effects of carnosine treatment alone and in combination with ACE inhibition, a clinically established nephroprotective drug in diabetic nephropathy.
Male Sprague–Dawley rats were injected i.v. with streptozotocin (STZ) to induce diabetes. After 4weeks, rats were unilaterally nephrectomized and randomized for 24weeks of treatment with carnosine, lisinopril or both.
Renal CN1 protein concentrations were increased under diabetic conditions which correlated with decreased anserine levels. Carnosine treatment normalized CN1 abundance and reduced glucosuria, blood concentrations of glycosylated hemoglobin (HbA1c), carboxyl-methyl lysine (CML), N-acetylglucosamine (GlcNac; all p<0.05 vs. non-treated STZ rats), reduced cataract formation (p<0.05) and urinary albumin excretion (p<0.05), preserved podocyte number (p<0.05) and normalized the increased renal tissue CN1 protein concentration. Treatment with lisinopril had no effect on HbA1C, glucosuria, cataract formation and CN1 concentration, but reduced albumin excretion rate more effectively than carnosine treatment (p<0.05). Treatment with both carnosine and lisinopril combined the effects of single treatment, albeit without additive effect on podocyte number or albuminuria.
Increased CN1 amount resulted in decreased anserine levels in the kidney. Both carnosine and lisinopril exert distinct beneficial effects in a standard model of diabetic nephropathy. Both drugs administered together combine the respective effects of single treatment, albeit without exerting additive nephroprotection.
•Carnosine treatment has renoprotective function in diabetic rats.•Renoprotection differs from the effect of the ACE inhibitor lisinopril.•Carnosinase activity correlates with anserine levels in the kidney.•Carnosine and lisinopril together combine the effect of single treatment.
Purpose
To evaluate feasibility of automatic software-based path proposals for CT-guided percutaneous biopsies.
Methods
Thirty-three patients (60
±
12 years) referred for CT-guided biopsy of focal ...liver lesions were consecutively included. Pre-interventional CT and dedicated software (FraunhoferMeVis Pathfinder) were used for (semi)automatic segmentation of relevant structures. The software subsequently generated three path proposals in downward quality for CT-guided biopsy. Proposed needle paths were compared with consensus proposal of two experts (comparable, less suitable, not feasible). In case of comparable results, equivalent approach to software-based path proposal was used. Quality of segmentation process was evaluated (Likert scale, 1
=
best, 6
=
worst), and time for processing was registered.
Results
All biopsies were performed successfully without complications. In 91 % one of the three automatic path proposals was rated comparable to experts’ proposal. None of the first proposals was rated not feasible, and 76 % were rated comparable to the experts’ proposal. 7 % automatic path proposals were rated not feasible, all being second choice (
n
=
1
) or third choice (
n
=
6
). In 79 %, segmentation at least was good. Average total time for establishing automatic path proposal was 42
±
9 s.
Conclusion
Automatic software-based path proposal for CT-guided liver biopsies in the majority provides path proposals that are easy to establish and comparable to experts’ insertion trajectories.
A semisynthetic antibody library composed of single chain Fv fragments (scFv) was constructed by replacing the heavy chain CDR3 region of a human scFv by a random sequence of eight amino acids using ...trinucleotide codons. After cloning into a phage display vector, an antibody library was generated with a complexity of 8 × 108 independent clones. The library was screened for binders to dinitrophenol, fluorescein isothiocyanate and 3-nitro-4-hydroxy-5-iodophenylacetic acid. scFv antibodies that specifically bound the antigen were obtained in each case.
Moderne Bildgebung von Nierentumoren Clevert, D.-A.; Sterzik, A.; Braunagel, M. ...
Urologe. Ausgabe A,
04/2013, Letnik:
52, Številka:
4
Journal Article
Zusammenfassung
Die bildgebenden Verfahren stellen bei Patienten mit Verdacht auf Nierenraumforderungen die Hauptsäule der klinischen Diagnostik dar. In den letzten Jahren haben sich enorme ...Fortschritte erzielen lassen, die eine genaue artdiagnostische Einordnung von Nierenpathologien in der Mehrzahl der Fälle zweifelsfrei erlauben. Nach wie vor ist die Methode der ersten Wahl die Ultraschalluntersuchung, wobei für die Beurteilung von Nierenraumforderungen KM gegeben werden sollte. Die hier vorliegende Arbeit zeigt das Potential dieser Modalität ebenso auf wie neuste Entwicklungen auf dem Gebiet der Mehrzeilencomputertomographie, bei der besonders die sog. „Dual energy-Bildgebung“ hervorzuheben ist – diese hat das Potential zu signifikanter Dosisreduktion und Verbesserung der Charakterisierung von Nierentumoren. Weiterhin kommt die Magnetresonanztomographie bei unklaren Befunden der beiden zuvor genannten Verfahren sowie bei jungen Patienten und bekannter Allergie gegen jodhaltiges KM zum Einsatz. Sie erlaubt mittels hoher Feldstärken, schneller Gradientenmagneten und stark verbesserter Ortsauflösung eine sehr detailgenaue Abbildung von Nierenraumforderungen.
Die Lektüre der hier vorliegenden Arbeit soll unseren urologischen Kollegen den Stellenwert der oben genannten Verfahren sowie ihre Indikationen und Kontraindikationen nahebringen; zudem wird eine Übersicht über die wichtigsten Nierenraumforderungen und ihre radiologische Darstellung gegeben.
Modern imaging of kidney tumors Clevert, D-A; Sterzik, A; Braunagel, M ...
Urologe. Ausgabe A
52, Številka:
4
Journal Article
If a renal mass is suspected on clinical examination or ultrasound the finding has to be confirmed by cross-sectional imaging. Methods that are used include multidetector-row computed tomography ...(MDCT) and magnetic resonance imaging (MRI). Also contrast-enhanced ultrasound has been successfully implemented in renal imaging and now plays a major role in the differentiation of benign from malignant renal masses. In expert hands it can be used to show very faint vascularization and subtle enhancement. The MDCT technique benefits from the recently introduced dual energy technology that allows superior characterization of renal masses in a single-phase examination, thereby greatly reducing radiation exposure. For young patients and persons allergic to iodine MRI should be used and it provides excellent soft tissue contrast and visualizes contrast enhancement kinetics in multiphase examinations.This article aims at giving a comprehensive overview of these different imaging modalities, their clinical indications and contraindications, as well as a description of imaging findings of various renal masses.
A method for the facile simultaneous mutagenesis of complementary-determining regions (CDRs) in a single chain antibody (scFv) is described. Overlapping sets of oligonucleotides containing random ...sequences within the CDRs corresponding to the heavy chain variable region (VH) jointed to a linker peptide (J) and the light chain variable region (VL) were extended under PCR conditions to full-length genes. These gene products were then further amplified using short PCR primers containing complementary overlaps between the 3' and 5' ends of the VH-J and VL genes respectively. In a final step, the VH-J and VL gene products were mixed and assembled into scFv DNA products by overlap extension under standard PCR conditions. Sequence analyses indicated that the method is basically successful. However, some deletions were observed, which probably reflects difficulties in the automatic synthesis of long degenerate oligonucleotides.
Expression vectors for surface display and production of single-chain (Fv) antibodies (scAb) have been constructed based on the phagemid pSEX, which expresses DNA encoding a scAb fused to the gene ...III product of filamentous phage Breitling et al., Gene 104 (1991) 147-153. A smaller version of this phagemid, pSEX20, was made by removing an unnecessary cat. To produce a vector for the surface display of other proteins and peptides, the scAb of pSEX20 was substituted by a polycloning site (MCS) to give pSEX40. For the presentation of Ab on the surface of Escherichia coli, phagemid pAP10 was derived from pSEX20 by substituting gene III with a gene encoding the peptidoglycan-associated lipoprotein (PAL). Vectors for producing scAb that can be purified by antibody and metal affinity chromatography were constructed by substituting gene III in the vector pSEX20 with DNA encoding a peptide with a C-terminal epitope recognised by a monoclonal antibody (phagemid pOPE40) or with five C-terminal histidines (pOPE 90).
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