Coronary magnetic resonance angiography for assessment of the stent lumen: a phantom study.

PURPOSE: To evaluate the feasibility of visualizing the stent lumen using coronary magnetic resonance angiography in vitro. MATERIAL AND METHODS: Nineteen different coronary stents were implanted in plastic tubes with an inner diameter of 3 mm. The tubes were positioned in a plastic container filled with gel and included in a closed flow circuit (constant flow 18 cm/sec). The magnetic resonance images were obtained with a dual inversion fast spin-echo sequence. For intraluminal stent imaging, subtraction images were calculated from scans with and without flow. Subsequently, intraluminal signal properties were objectively assessed and compared. RESULTS: As a function of the stent type, various degrees of in-stent signal attenuation were observed. Tantalum stents demonstrated minimal intraluminal signal attenuation. For nitinol stents, the stent lumen could be identified, but the intraluminal signal was markedly reduced. Steel stents resulted in the most pronounced intraluminal signal voids. CONCLUSIONS: With the present technique, radiofrequency penetration into the stents is strongly influenced by the stent material. Thesefindings may have important implicationsforfuture stent design and stent imaging strategies.

Bacterial community structure of a pesticide-contaminated site and assessment of changes induced in community structure during bioremediation.

The introduction of culture-independent molecular screening techniques, especially based on 16S rRNA gene sequences, has allowed microbiologists to examine a facet of microbial diversity not necessarily reflected by the results of culturing studies. The bacterial community structure was studied for a pesticide-contaminated site that was subsequently remediated using an efficient degradative strain Arthrobacter protophormiae RKJ100. The efficiency of the bioremediation process was assessed by monitoring the depletion of the pollutant, and the effect of addition of an exogenous strain on the existing soil community structure was determined using molecular techniques. The 16S rRNA gene pool amplified from the soil metagenome was cloned and restriction fragment length polymorphism studies revealed 46 different phylotypes on the basis of similar banding patterns. Sequencing of representative clones of each phylotype showed that the community structure of the pesticide-contaminated soil was mainly constituted by Proteobacteria and Actinomycetes. Terminal restriction fragment length polymorphism analysis showed only nonsignificant changes in community structure during the process of bioremediation. Immobilized cells of strain RKJ100 enhanced pollutant degradation but seemed to have no detectable effects on the existing bacterial community structure.

99mTc-sestamibi imaging and bone marrow karyotyping in the assessment of multiple myeloma and MGUS

AIM: The first pathogenetic step in multiple myeloma is the emergence of a limited number of clonal plasma cells, clinically known as monoclonal gammopathy of undetermined significance (MGUS). Patients with MGUS do not have symptoms or end-organ damage but they do have a 1% annual risk of progression to multiple myeloma or related malignant disorders. With progression of MGUS to multiple myeloma, complex genetic events occur in the neoplastic plasma cell. Karyotyping and fluorescence in-situ hybridization (FISH) were shown to be of prognostic value in patients with multiple myeloma. Tc-sestamibi imaging reflects myeloma disease activity in bone marrow with very high sensitivity and specificity predicting disease evolution. This study was undertaken to evaluate the role of Tc-sestamibi imaging and cytogenetic analysis in prognosis prediction of MGUS and multiple myeloma. METHODS: We enrolled 30 consecutive patients with a confirmed diagnosis of multiple myeloma or MGUS. Bone marrow biopsy and biochemical staging according to the International Staging System (ISS) were performed in all cases. Karyotype analysis and FISH were performed in 11 of 12 patients with MGUS and in 17 of 18 patients with multiple myeloma having adequate metaphases. RESULTS: The karyotype was abnormal in four of 11 MGUS and in six of 17 multiple myeloma. Abnormalities of chromosome 13 were present in one case of MGUS and in six cases of multiple myeloma whereas the involvement of immunoglobulin was observed in one case of multiple myeloma. An abnormal FISH panel was found in four MGUS and nine multiple myeloma patients. All patients with MGUS showed a normal MIBI scan (score 0). Among patients with multiple myeloma only three, all with ISS stage I, showed a normal scan while a positive scan was obtained in others (score range, 1-7). The MIBI uptake was strongly related to the bone marrow plasma cell infiltration and to cytogenetic abnormalities. Particularly, a MIBI uptake score above 5 identified patients with poor prognosis encompassing all stage III multiple myeloma and three of seven stage II multiple myeloma. On the other hand all stage I and II patients having a MIBI score less than 5 showed a good prognosis. CONCLUSION: Both cytogenetic analysis and a MIBI scan add no relevant prognostic information to the ISS in patients with stage I and III multiple myeloma. The MIBI scan was of prognostic value in stage II multiple myeloma patients. Additionally, MIBI imaging may be useful to guide bone marrow biopsy in order to obtain adequate samples for cytogenetic analysis.

Gamma Knife radiosurgery after previous microvascular decompression decreases the chances of pain free in classical trigeminal neuralgia

Purpose: To evaluate the safety-efficacy of Gamma Knife surgery (GKS) as a second treatment for classical trigeminal neuralgia (CTN), and the influence of prior microvascular decompression (MVD). Methods: Between July 1992 and November 2010, 737 patients have been operated with GKRS for ITN and prospectively evaluated in Timone University Hospital in Marseille, France. Among these, 54 patients had a previous history of MVD. Radiosurgery using a Gamma Knife (model B or C or Perfexion) was performed on the basis of on both MR and CT targeting. A single 4 mm isocenter was positioned in the cisternal portion of the trigeminal nerve at a median distance of 7.6 mm (range 3.9-11.9) anteriorly to the emergence of the nerve (retrogasserian target). A median maximum dose of 85 Gy (range 70-90) was delivered. Here, the 45 patients with previous MVD and a follow-up longer than one year are evaluated (the patients with megadolichobasilar artery compression and multiple sclerosis were excluded). Results: The median age in this series was 56.75 years (range 28.09-82.39). The median follow-up period was 39.48 months (range 14.10-144.65). All the patients had a past history of surgery, with at least one previous failed MVD, but also radiofrequency lesion (RFL) in 16 patients (35.6%), balloon microcompression in 7 (15.6%) and glycerol rhizotomy in 1 (2.2%). Thirty-five patients (77.8%) were initially pain free after GKS within a median time of 14 days (range 0, 180). Patients from this group had less probability of being pain free compared to our global population of essential trigeminal neuralgia without previous MVD history (p=0.010, hazard ratio of 0.64). Their probability of remaining pain free at 3, 5, 7 and 10 years was 66.5%, 59.1%, 59.1% and 44.3%, respectively. Twelve patients (34.3%) initially pain free experienced a recurrence with a median delay of 31.21 months (range 3.40-89.93). The hypoesthesia actuarial rate at 1 year was 9.1% and remained stable till 12 years with a median delay of onset of 8 months (range 8-8). Conclusions: Retrogasserian GKS proofed to be safe and effective on the long-term basis even after failed previous MVD. Even if the initial result of pain free was only 77.8%, the toxicity was low with only 9.1% hypoesthesia. No patient reported a bothersome hypoesthesia. The probability of maintaining pain relief in the long-term was of 44.3% at 10 years.

Data bases for the assessment of medical technologies: examples from Europe.

The assessment of medical technologies has to answer several questions ranging from safety and effectiveness to complex economical, social, and health policy issues. The type of data needed to carry out such evaluation depends on the specific questions to be answered, as well as on the stage of development of a technology. Basically two types of data may be distinguished: (a) general demographic, administrative, or financial data which has been collected not specifically for technology assessment; (b) the data collected with respect either to a specific technology or to a disease or medical problem. On the basis of a pilot inquiry in Europe and bibliographic research, the following categories of type (b) data bases have been identified: registries, clinical data bases, banks of factual and bibliographic knowledge, and expert systems. Examples of each category are discussed briefly. The following aims for further research and practical goals are proposed: criteria for the minimal data set required, improvement to the registries and clinical data banks, and development of an international clearinghouse to enhance information diffusion on both existing data bases and available reports on medical technology assessments.

High-field (3T) magnetic resonance defecography with functional assessment of the evacuation phase : a pictorial essay : P10

Purpose: Dynamic high-field magnetic resonance (MR) defecography including the evacuation phase is a promising tool for the assessment of functional pelvic disorders, nowadays seen with increasing frequency in elderly women in particular. Learning objectives: 1. To describe the adequate technique of dynamic high-field MRI (3T) in assessing pelvic floor disorders. 2. To provide an overview of the most common pathologies occurring during the evacuation phase, especially in comparison with results of conventional defecography. Methods and materials: After description of the ideal technical parameters of MR defecography performed in supine position after gel rectal filling with a 3 Tesla unit and including the evacuation phase we stress the importance of using a standardized evaluation system for the exact assessment of pelvic floor pathophysiology. Results: The typical pelvic floor disorders occurring before and/or during the evacuation phase, such as sphincter insufficiency, vaginal vault and/or uterine prolapse, cystourethrocele, peritoneo-/ entero-/ sigmoïdocele or rectal prolapse, are demonstrated. The difference between the terms "pelvic floor descent" and "pelvic floor relaxation" are pictorially outlined. MR results are compared with these of conventional defecography. Conclusion: Exact knowledge about the correct technique including the evacuation phase and the use of a standardized evaluation system in assessing pelvic floor disorders by dynamic high-field MRI is mandatory for accurate and reproducible diagnosis.

A dynamic assessment of medication-taking behavior during pregnancy and postpartum: should cART adherence be reinforced during postpartum?

This study compared adherence (persistence and execution) during pregnancy and postpartum in HIV-positive women having taken part in the adherence-enhancing program of the Community Pharmacy of the Department of Ambulatory Care and Community Medicine in Lausanne between 2004 and 2012. This interdisciplinary program combined electronic drug monitoring and semi-structured, repeated motivational interviews. This was a retrospective, observational study. Observation period spread over from first adherence visit after last menstruation until 6 months after childbirth. Medication-taking was recorded by electronic drug monitoring. Socio-demographic and delivery data were collected from Swiss HIV Cohort database. Adherence data, barriers and facilitators were collected from pharmacy database. Electronic data were reconciled with pill-count and interview notes in order to include reported pocket-doses. Execution was analyzed over 3-day periods by a mixed effect logistic model, separating time before and after childbirth. This model allowed us to estimate different time slopes for both periods and to show a sudden fall associated with childbirth. Twenty-five pregnant women were included. Median age was 29 (IQR: 26.5, 32.0), women were in majority black (n_17,68%) and took a cART combining protease and nucleoside reverse transcriptase inhibitors (n_24,96%). Eleven women (44%) were ART-naı¨ve at the beginning of pregnancy. Twenty women (80%) were included in the program because of pregnancy. Women were included at all stages of pregnancy. Six women (24%) stopped the program during pregnancy, 3 (12%) at delivery, 4 (16%) during postpartum and 12 (48%) stayed in program at the end of observation time. Median number of visits was 4 (3.0, 6.3) during pregnancy and 3 (0.8, 6.0) during postpartum. Execution was continuously high during pregnancy, low at beginning of postpartum and increased gradually during the 6 months of postpartum. Major barriers to adherence were medication adverse events and difficulties in daily routine. Facilitators were motivation for promoting child-health and social support. The dramatic drop and very slow increase in cART adherence during postpartum might result in viral rebound and drug resistance. Although much attention is devoted to pregnant women, interdisciplinary care should also be provided to women in the community during first trimester of postpartum to support them in sustaining cART adherence.

QuantiFERON®-CMV assay for the assessment of cytomegalovirus cell-mediated immunity.

Cytomegalovirus (CMV) infection has historically been a major complication among immunocompromised patients, such as solid-organ and stem-cell transplant recipients and patients with advanced HIV infection. While the introduction of antiretroviral therapy has almost eradicated CMV infection in HIV-infected patients, CMV disease remains a significant problem in transplant recipients once antiviral prophylaxis is discontinued. QuantiFERON(®)-CMV allows the assessment of cellular immunity against CMV by detecting the production of IFN-γ following in vitro stimulation with CMV antigens. Preliminary studies have shown a correlation between a lack of detectable cell-mediated immunity measured by the QuantiFERON-CMV assay and a higher incidence of CMV infection and disease in immunocompromised patients. Measurement of cell-mediated immunity against CMV appears to be a promising strategy to identify patients at highest risk for the development of CMV disease and, therefore, to individualize preventive strategies for CMV in transplant recipients.

Initial assessment of safety and clinical feasibility of irreversible electroporation in the focal treatment of prostate cancer.

BACKGROUND: To evaluate the safety and clinical feasibility of focal irreversible electroporation (IRE) of the prostate. METHODS: We assessed the toxicity profile and functional outcomes of consecutive patients undergoing focal IRE for localised prostate cancer in two centres. Eligibility was assessed by multi-parametric magnetic resonance imaging (mpMRI) and targeted and/or template biopsy. IRE was delivered under transrectal ultrasound guidance with two to six electrodes positioned transperineally within the cancer lesion. Complications were recorded and scored accordingly to the NCI Common Terminology Criteria for Adverse Events; the functional outcome was physician reported in all patients with at least 6 months follow-up. A contrast-enhanced MRI 1 week after the procedure was carried out to assess treatment effect with a further mpMRI at 6 months to rule out evidence of residual visible cancer. RESULTS: Overall, 34 patients with a mean age of 65 years (s.d.=±6) and a median PSA of 6.1 ng ml(-1) (interquartile range (IQR)= 4.3-7.7) were included. Nine (26%), 24 (71%) and 1 (3%) men had low, intermediate and high risk disease, respectively (D'Amico criteria). After a median follow-up of 6 months (range 1-24), 12 grade 1 and 10 grade 2 complications occurred. No patient had grade >/= 3 complication. From a functional point of view, 100% (24/24) patients were continent and potency was preserved in 95% (19/20) men potent before treatment. The volume of ablation was a median 12 ml (IQR=5.6-14.5 ml) with the median PSA after 6 months of 3.4 ng ml(-1) (IQR=1.9-4.8 ng ml(-1)). MpMRI showed suspicious residual disease in six patients, of whom four (17%) underwent another form of local treatment. CONCLUSIONS: Focal IRE has a low toxicity profile with encouraging genito-urinary functional outcomes. Further prospective development studies are needed to confirm the functional outcomes and to explore the oncological potential.

Comparison of a multiplexed bead-based assay with an immunofluorescence and an enzyme-immuno assay for the assessment of Epstein-Barr virus serologic status

Dans cette étude, nous avons testé la performance diagnostique d'une nouvelle technique d'analyse multiplexée qui permet la détection d'anticorps de différentes spécificités dans la même réaction. En l'absence de gold standard, nous avons choisi de comparer la performance diagnostique de l'analyse avec deux méthodes de référance que sont l'IF et EIA, et avec un consensus déterminé selon une règle de majorité entre les trois méthodes.¦393 sérums analysés par IF, conservés par congélation, ont été décongelés pour être analysés par EIA et BBA. Pour chaque sérum, les anticorps recherchés ont été les anti-VCA (Viral Capsid Antigen) IgM, anti-VCA IgG et anti-EBNA (Epstein-Barr Nuclear Associated) IgG. Les échantillons ont été classés en cinq groupes selon les résultats de l'IF : séronégatifs, infections aiguës, infections anciennes et deux types d'indéterminés.¦Pour chaque méthode, le résultat numérique (index ou titre) des analyses est converti en termes de positif, négatif ou douteux. Pour le résultat de chaque type d'anticorps, un consensus est établi selon une règle de majorité entre les trois méthodes, permettant une interprétation du stade de l'infection. Puis l'interprétation de chacune des méthodes a été comparée au consensus. Nous avons également comparé les trois méthodes les unes aux autres concernant la détection des anticorps.¦Globalement, nous observons une bonne corrélation qualitative entre les trois approches pour détecter les anti-VCA IgG et IgM. Pour pour les anti-EBNA IgG, il y a une divergence notable entre l'IF et les deux autres méthodes, l'IF apparaissant moins sensible que les autres méthodes, résultant en un nombre accru d'interprétations indéterminées du stade de l'infection.¦L'origine de cette divergence ne peut être due à une perte d'anticorps liée au stockage de longue durée des échantillons. En effet, EIA et BBA restent plus sensibles que IF, dont l'analyse a été faite sur des sérums frais.¦Cette divergence ne semble pas non plus être due aux différents antigènes utilisés par les trois méthodes. EIA et BBA utilisent le même antigène recombinant EBNA-1, alors que l'IF utilise des "cellules lymphoïdes choisies pour leur production sélective d'antigènes EBNA". Ces cellules sont probablement des cellules infectées par EBV qui devraient exprimer plus d'antigènes de latence que seul EBNA-1. Cette différence devrait donc plutôt en principe résulter en une meilleure sensibilité de l'IF par rapport aux deux autres méthodes.¦Les anti-EBNA IgG peuvent disparaître chez les patients immunocompromis chez qui se produit une réactivation d'EBV. Nous avons donc recherché le status immunitaire des patients du groupe dont les sérums étaient négatifs pour anti-EBNA IgG en IF et positifs par les autres méthodes: seulement 28 des 70 patients étaient immunocompromis.¦Par conséquent, il est probable que dans la majorité de ces résultats discordants, les anticorps anti-EBNA IgG détectés par BBA et EIA sont de vrais positifs non décelés par l'IF.¦En conclusion, BBA est meilleur que la méthode de référance qu'est l'IF, et est égal à EIA en ce qui concerne la performance diagnostique. En outre, ces deux nouvelles méthodes offrent une économie de temps en raison de manipulations moindres, et ne requièrent aucune formation en microscopie à fluorescence. Elles sont également plus économes en échantillons que IF. BBA a l'avantage de n'avoir besoin que de deux analyses pour donner un diagnostique, alors que IF et EIA ont en besoin d'une par anticorps. Enfin, BBA dispose de contrôles internes permettant de reconnaître les liaisons non antigène-spécifiques des anticorps. Par contre, BBA nécessite l'achat d'un lecteur par cytométrie de flux assez coûteux.