Intestinal persistence of a plasmid harbouring the OXA-48 carbapenemase gene after hospital discharge.

To study intestinal colonization by OXA-48-producing Klebsiella pneumoniae (KpO48) after hospital discharge, stool samples from 22 previously colonized subjects were collected. Time from discharge was 33-611 days, without readmissions. Eight subjects (36%) were identified as blaOXA-48 gene carriers. In all of them the hospital-acquired strain of KpO48 had been lost, and the gene was harboured by other strains of K. pneumoniae, Klebsiella oxytoca and/or Escherichia coli. Our findings show intestinal persistence for several months of a plasmid harbouring the OXA-48 carbapenemase gene in a significant proportion of individuals in the absence of antibiotic treatment.

Meningitis bacteriana por Streptococcus pyogenes: revisión de la literatura / Bacterial meningitis due to Streptococcus pyogenes: literature review

Introducción: el Streptococcus pyogenes (S. pyogenes) es una etiología poco habitual de meningitis bacteriana a pesar de ser un germen que frecuentemente produce infecciones en otras localizaciones en la edad pediátrica. Material y métodos: se revisaron los casos de bacteriemia por S. pyogenes y los factores de riesgo asociados en la base de datos del Servicio de Microbiología del Hospital Universitario La Paz desde junio de 2002 a junio de 2012. Resultados: únicamente se encontró un caso de bacteremia por S. pyogenes asociado a meningitis, que se describe en este artículo. Conclusiones: a pesar de su baja incidencia, se debe tener en cuenta el S. pyogenes en el diagnóstico diferencial de meningitis bacterianas, especialmente en pacientes con factores de riesgo asociados (AU)

Introduction: Streptococcus pyogenes (S. pyogenes) is a rare cause of meningitis despite being a common source of pediatric infections in other sites. Material and methods: A search was performed of the pediatric patients with S. pyogenes bacteremia in the microbiology database of the Hospital Infantil La Paz from June 2002 until June 2012. Results: A single case of S. pyogenes meningitis was found and is reported in this article. Conclusions: Despite its low incidence, S. pyogenes should be considered in the differential diagnosis of meningitis, particularly in patients with associated risk factors (AU)

Molecular MR imaging for the evaluation of the effect of dynamic stabilization on lumbar intervertebral discs.

The dynamic stabilization of lumbar spine is a non-fusion stabilization system that unloads the disc without the complete loss of motion at the treated motion segment. Clinical outcomes are promising but still not definitive, and the long-term effect on instrumented and adjacent levels is still a matter of discussion. Several experiments have been devised in order to gain a better understanding of the effect of the device on the intervertebral disc. One of the hypotheses was that while instrumented levels are partially relieved from loading, adjacent levels suffer from the increased stress. But this has not been proved yet. The aim of this study was to investigate the long-term effect of dynamic stabilization in vivo, through the quantification of glycosaminoglycans (GAG) concentration within instrumented and adjacent levels by means of the delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) protocol. Ten patients with low back pain, unresponsive to conservative treatment and scheduled for Dynesys implantation at one to three lumbar spine levels, underwent the dGEMRIC protocol to quantify GAG concentration before and 6 months after surgery. Each patient was also evaluated with visual analog scale (VAS), Oswestry, Prolo, Modic and Pfirrmann scales, both at pre-surgery and at follow-up. Six months after implantation, VAS, Prolo and Oswestry scales had improved in all patients. Pfirrmann scale could not detect any change, while dGEMRIC data already showed a general improvement in the instrumented levels: GAG was increased in 61% of the instrumented levels, while 68% of the non-instrumented levels showed a decrease in GAG, mainly in the posterior disc portion. In particular, seriously GAG-depleted discs seemed to have the greatest benefit from the Dynesys implantation, whereas less degenerated discs underwent a GAG depletion. dGEMRIC was able to visualize changes in both instrumented and non-instrumented levels. Our results suggest that the dynamic stabilization of lumbar spine is able to stop and partially reverse the disc degeneration, especially in seriously degenerated discs, while incrementing the stress on the adjacent levels, where it induces a matrix suffering and an early degeneration.

MR imaging of the knee in patients with medial unicompartmental arthroplasty: comparison among sequences at 1.5 T.

PURPOSE: This study was done to test a series of magnetic resonance (MR) imaging sequences of the knee after medial unicompartmental arthroplasty. MATERIALS AND METHODS: Four patients who had undergone Oxford III medial unicompartmental arthroplasty underwent 1.5-T MR imaging of the operated knee using coronal sequences: T1-weighted spin-echo (SE), T1-weighted turbo SE (TSE), proton-density (PD)- and T2-weighted TSE, T1-weighted gradient echo (GE), short-tau inversion recovery (STIR), multi echo data image combination (MEDIC), T2*-weighted GE, volumetric interpolated breath-hold examination (VIBE), and dual-echo steady state (DESS). For each sequence, we evaluated the visibility of the anatomical structures of the central pivot, lateral compartment, and anterior compartment using a semiquantitative score (0=total masking; 1=insufficient visibility; 2=sufficient visibility; 3=optimal visibility). The sum of the scores given to each sequence was divided by the maximal sum, obtaining a percentage visibility index. Friedman and sign tests were used for statistical analysis. RESULTS: MR examination time was 30-32 min. No patients reported pain, heat or other local discomfort. The visibility index ranged between 83% and 89% for the first four sequences without significant differences among them, 58% for STIR and 11%-36% for the last five sequences. Significant differences were found between each of the four first sequences and the remaining sequences (p<0.004) and between STIR and the last five sequences (p<0.008). CONCLUSIONS: MR imaging of the knee after medial unicompartmental arthroplasty was not associated with adverse events. An imaging protocol including SE, TSE and STIR sequences could be used to study the knee with unicompartmental arthroplasty.

Can the MRI signal of aggressive fibromatosis be used to predict its behavior?

PURPOSE: Aggressive fibromatosis is an invasive non-metastasizing soft-tissue tumor. Until recently, the standard treatment combined surgery and radiation therapy, but new studies reported that conservative strategies with or without medical treatment could be the best management. The aim of this study was to analyze and correlate the size and MR imaging signal features of aggressive fibromatosis with its behavior in order to choose the best treatment. MATERIALS AND METHODS: Between March 1985 and December 2005, 27 patients with at least 2 consecutive MRI examinations and no surgery or radiation therapy in between were recorded. There were 9 men and 18 women, and median age was 31 years. They underwent 107 MRI examinations of 47 lesions, 29 of which were medically treated, while the remaining 18 did not receive any drug administration. The size and signal changes of each lesion were studied over time on T2- and/or T1-weighted sequences after injection of contrast medium. RECIST criteria were used for size: only a 30% decrease or a 20% increase in the size of the main dimension was considered significant. We classified the appearance of the signal into six categories in order of increasing intensity and then we established the related variations over time. RESULTS: The size of 79% of the lesions in the treated group and 82% in the untreated group remained stable. The initial signal of stable lesions or those exhibiting an increase in size was most frequently high. There was a high rate of signal stability over time, whatever the initial signal and size changes. Changes in size were not correlated with the initial MR signal. A decrease in size associated with a decreased signal was observed in three cases exclusively in the treated group. CONCLUSION: Fibromatoses are a group of soft-tissue tumors with variable characteristics on MRI, but it is not possible to predict their behavior based on the MRI signal.

Protein biochip array of adhesion molecule expression in peripheral blood of patients with nasal polyposis.

Nasal polyposis is a chronic non-infectious inflammatory disease of the nasal and paranasal cavity mucosa of unknown multifactorial origin in which inflammatory cells, and in particular eosinophils, seem to play a pivotal role. Eosinophil migration from the bloodstream to nasal polyps is considered to be specific and is a complex process involving several different molecules such as ICAM-1, VCAM-1, and L-, P- and E-selectins. The aim of this study was to investigate, using a protein biochip array technology, the concentrations of these molecules in the peripheral blood of a group of patients affected by nasal polyposis. Patients exhibited a significantly higher expression of VCAM-1, E-selectin, and L-selectin compared to healthy controls, and Spearman's rank correlation test limited to the molecules with significant betweengroup differences demonstrated a significant correlation between VCAM-1 and E-selectin, VCAM-1 and L-selectin, and Eselectin and L-selectin. The results of this investigation are in line with those coming from various imunohistochemical analyses, and seem to confirm the role of inflammation in the pathogenesis of nasal polyposis. These molecules may also represent novel therapeutic targets in the treatment of nasal polyps, and may allow the selection of pharmacological prophylactics that would allow effective inhibition of the inflammation induced by a given allergen.

Superior thyroid artery lesion after US-guided chemical parathyroidectomy: angiographic diagnosis and treatment by embolization.

A 71-year-old woman presented with a life-threatening thyroid hemorrhage after US-guided chemical parathyroidectomy. The diagnosis was made by angiography followed by immediate embolization of a pseudoaneurysm of the left superior thyroid artery. Embolization controlled the hemorrhage, obviating the need for surgery. The patient made a full recovery with no evidence of further hemorrhage. Pseudoaneurysm of the superior thyroid artery is a rare cause of hemorrhage and percutaneous embolization is an effective method of treatment.

Ruptured suprarenal artery aneurysm: angiographic diagnosis and treatment by selective embolization.

The case of a 78-year-old man with retroperitoneal hemorrhage due to a ruptured right inferior suprarenal artery aneurysm is presented. The diagnosis was made by angiography which allowed immediate embolization of the neck of the aneurysm, controlling hemorrhage and obviating the need for surgery. The patient made a full recovery with no evidence of further hemorrhage.

[Treatment of superior vena cava syndrome by metal stents. Preliminary experience]. / Trattamento della sindrome della vena cava superiore con stent metallici. Esperienza preliminare.

This study was aimed at verifying the feasibility of stent placement in superior vena cava syndrome (SVCS). From April, 1993, to February 1995, fifteen patients (12 men, 3 women, age range: 48-72 years, average age: 58 years), were treated for malignant stenoses involving superior vena cava in 9 cases, right innominate vein in 3, left innominate vein in 2 and subclavian veins in 1. All patients had been submitted to CT angiography and digital venography to assess side, length and type of the stenosis. In 6 patients locoregional fibrinolysis (with urokinase) was performed. The stenosis was successfully dilated by balloon catheter and the stent was finally removed. Subclavian and innominate veins stenoses were treated with Wallstent, using brachial approach, while stenoses of superior vena cava required transfemoral catheterization for Gianturco-Rosch "Z" stent placement. A control venogram was performed after stenting, with the evaluation of pre/post stent pressure gradient, and later at 1, 3 and 6 months. The stents were positioned in all patients with immediate technical success; no major complications occurred. Two recurrences were successfully resolved. Radiation and/or medical therapy without vascular disobstruction showed worse results in the treatment of superior vena cava syndrome. The percutaneous placement of self-expandable stents should be not only the therapeutic alternative to surgery but the method of choice in these pathologic conditions.

Malignant biliary obstruction treated by Wallstents and Strecker tantalum stents: a retrospective review.

PURPOSE: To evaluate retrospectively the role and the effectiveness of self-expandable Wallstents and balloon-expandable Strecker stents in patients with inoperable malignant obstruction of the biliary tree. METHODS: Fifty patients with malignant biliary obstruction were treated from August 1991 to August 1992 by percutaneous placement of 55 metallic endoprostheses (39 Wallstents, 16 Strecker stents). All patients were followed by clinical evaluation, laboratory data, and ultrasonographic examination until death. RESULTS: Wallstent placement was successful in 36 patients without procedure-related complications. One partial occlusion after 1 year was resolved by percutaneous balloon dilatation. Fourteen patients were treated with 16 Strecker stents. Stenting was unsuccessful in four cases; four occlusions (after 6 h, 48 h, 2 and 6 months) were encountered. CONCLUSION: Wallstent endoprostheses have good results and long-term patency. There were some problems with Strecker stents during the placement and there was a higher occlusion rate.

[Retrospective analysis of color Doppler ultrasonography and flowmetry findings in solid nodular pathology of the breast]. / Analisi retrospettiva dei rilievi con eco color Doppler e flussimetrici nella patologia nodulare solida della mammella.

The authors tried to identify useful flowmetric values and color-Doppler patterns for the differential diagnosis between benign and malignant solid breast lesions. To this purpose, 106 patients with breast nodules detected at mammography and/or high resolution US were examined. A US scanner with a linear 7.5 MHz transducer, a narrow sample volume, a PRF ranging (650-800 Hz) and a wall filter value of 50 Hz were used. Three parameters were considered: the number vascular sites, systolic peak velocity and pulsatility index. All these parameters related to tumor volume. Several (> 2) vascular sites, high peak velocity and quite high pulsatility index were demonstrated in malignant tumors (46 lesions). Among benign tumors no vascular site was identified in 32 of 60 lesions and no more than 2 sites were identified in 26 of 60 lesions, except for 2 phylloides tumors. Sensitivity, specificity, positive and negative predictive values and overall accuracy rates were, as for the "vascular sites" parameter, 78%, 96%, 94%, 85%, 88%, respectively; as regards the "peak systolic velocity" 81%, 86%, 89%, 75%, 83% respectively; as regards the "pulsatility index" 100%, 85%, 100%, 85%, 94% respectively.

[Transjugular intrahepatic portosystemic shunt (TIPS)]. / Derivazione porto-sistemica intraepatica per via transgiugulare (TIPS).

Transjugular intrahepatic portosystemic (TIPS) is radiological technique that has opened up new therapeutic horizons in the treatment of portal hypertension. Technically, the procedure includes catheterizing of the suprahepatic veins, prevalently right or middle, by means of transjugular access, and the creation of an intrahepatic path with the main portal branch. Later dilatation of the path by angioplasty and the application of a metallic stent at the site of the shunt complete the operation. Personal experience of 43 TIPS in 42 patients with a follow-up of 24 months is reported.

[Treatment of malignant occlusions of bile ducts by one-step technique using metallic endoprostheses. A multicenter study of 50 cases]. / Trattamento delle occlusioni maligne delle vie biliari mediante endoprotesi metalliche con tecnica "one-step". Studio policentrico di 50 casi.

Long-term patency and ease of insertion of self-expandable metallic stents seem to overcome the disadvantages of plastic stents, changing the therapeutic approach to unresectable biliary tree malignancies. Their high cost is the main problem of metallic stents and reducing hospitalization time is a real opportunity to overcome this problem. Self-expandable stents could be the turning point to reduce overall costs. Fifty patients with malignant biliary tree obstruction (Zubrod performance status < 3) were treated with percutaneous placement of 58 Wallstent endoprostheses by the one-step technique. All patients had undergone thorough diagnostic exams - i.e., US, CT, PTC, ERCP with biopsy or brushing. Two major complications occurred in this series: a iatrogenic pseudoaneurysm requiring selective catheterization and embolization with Gianturco coils and a hepatic abscess six months after stent placement. Late stent occlusion occurred in six patients (12%) and was resolved by balloon dilatations. All patients were followed-up with clinical examinations, US and laboratory tests until death; median survival after stent placement was 122 days (range: 70 to 510 days). Average hospitalization time was 7 days with an acceptable cost reduction.

[The percutaneous treatment of purulent intrathoracic fluid collections in HIV+ patients]. / Trattamento percutaneo di raccolte purulente endotoraciche in pazienti HIV+.

Eighteen HIV+ patients with purulent fluid intrathoracic collections (16 pleural empyemas and 2 lung abscesses) and persistent sepsis were treated with percutaneous drainage; all patients had received antibiotics for 5-7 days at least. Empyemas and lung abscesses were cured (according to clinical and radiographic criteria) in all patients (100%). One major complication was successfully treated--i.e., a pneumothorax with a iatrogenic lesion of the internal mammary artery, requiring selective embolization. In our experience, CT is the method of choice to guide lesion puncture. Van Sonnenberg Sump catheters (12-16 F) have been inserted in the last six months with the Trocar technique. The maneuvers were successful in all cases, with good compliance and management of patients in a 9-25 days' period (mean: 14 days). In our experience, the percutaneous drainage of intrathoracic fluid collections in HIV+ patients should be considered the method of choice.

[Malignant occlusion of the bile ducts. Treatment with metallic endoprosthesis: Wallstent vs Strecker's stent]. / Occlusioni maligne delle vie biliari. Trattamento mediante endoprotesi metalliche: Wallstent vs stent di Strecker.

Stenting is the method of choice to relieve jaundice in the patients with inoperable malignant obstructions of the biliary tree. Over the last fifteen years, thousands of patients have been treated, if endoscopy failed or was unfeasible, with percutaneous transhepatic procedures: despite this wide experience, the role of conventional plastic endoprostheses is still debated, because these devices exhibit major limitations. The main objection to the use of Carey-Coons endoprostheses is the fact that a high rate of early occlusions has always been observed with plastic stents with a wide outer diameter (12-16 F). Metallic stents (self-expandable, Wallstent balloon-expandable Strecker stents) might solve these problems, especially in high-risk patients. The authors report their experience in 50 patients with midterm follow-up, a comparison of the two types of stents and their technical features.

[Technical and methodologic considerations on a new approach to the transjugular intrahepatic portosystemic shunt]. / Considerazioni tecnico-metodologiche su un nuovo approccio alla derivazione porto-sistemica per via transgiugulare (TIPS).

The authors report their experience with 10 transjugular intrahepatic portosystemic shunts (TIPS) in nine patients with severe portal hypertension; indications were rebleeding after sclerosing treatment in 8 cases and unmanageable ascitis in one case. The passage of the needle from the hepatic venous system into the portal venous system during the procedure may be technically difficult with both skin markers and US guidance, and several passages through liver parenchyma may be needed: this step is certainly the most critical one, for maneuver duration--and therefore risks--depend on it. Thus, in the last 6 patients a new method was used to easily identify portal bifurcation: a thin stainless platinum-tip guide-wire (0.018-inch diameter) was inserted, by epigastric approach under US guidance, through a fine Chiba needle (22 G) in the left main portal branch, dramatically reducing the number of failed punctures and maneuver duration. Both the above goals are to be reached to make TIPS easier and therefore advantage both patients and interventional radiologists.