Impact of participation in a surgical site infection surveillance network: results from a large international cohort study.

BACKGROUND: Surveillance of surgical site infections (SSIs) is a core component of effective infection control practices, though its impact has not been quantified on a large scale. AIM: To determine the time-trend of SSI rates in surveillance networks. METHODS: SSI surveillance networks provided procedure-specific data on numbers of SSIs and operations, stratified by hospitals' year of participation in the surveillance, to capture length of participation as an exposure. Pooled and procedure-specific random-effects Poisson regression was performed to obtain yearly rate ratios (RRs) with 95% confidence intervals (CIs), and including surveillance network as random intercept. FINDINGS: Of 36 invited networks, 17 networks from 15 high-income countries across Asia, Australia and Europe participated in the study. Aggregated data on 17 surgical procedures (cardiovascular, digestive, gynaecological-obstetrical, neurosurgical, and orthopaedic) were collected, resulting in data concerning 5,831,737 operations and 113,166 SSIs. There was a significant decrease in overall SSI rates over surveillance time, resulting in a 35% reduction at the ninth (final) included year of surveillance (RR: 0.65; 95% CI: 0.63-0.67). There were large variations across procedure-specific trends, but strong consistent decreases were observed for colorectal surgery, herniorrhaphy, caesarean section, hip prosthesis, and knee prosthesis. CONCLUSION: In this large, international cohort study, pooled SSI rates were associated with a stable and sustainable decrease after joining an SSI surveillance network; a causal relationship is possible, although unproven. There was heterogeneity in procedure-specific trends. These findings support the pivotal role of surveillance in reducing infection rates and call for widespread implementation of hospital-based SSI surveillance in high-income countries.

Imaging of thoracic aortic injury.

Isthmic aortic rupture or disruption should be systematically sought when there is high kinetic energy trauma to the thorax. This condition is extremely serious and life threatening. It needs to be diagnosed rapidly but diagnostic pitfalls must be avoided. CT angiography is the standard examination. The main CT signs of rupture or disruption of the thoracic aorta are periaortic hematoma, intimal flap, pseudo-aneurysm and contrast agent extravasation. There are three types of lesion: intimal, subadventitial or pseudo-aneurysmal, and complete rupture with lesion of the three tunicae, and it is important to grade them for better therapeutic management. The main diagnostic pitfalls of the CT scan are the presence of a ductus diverticulum and post-isthmic fusiform dilatation. Associated lesions must not be overlooked. The most common are ruptures of the aortic root and the thoracic aorta in the diaphragmatic hiatus.

Early presentation of primary glioblastoma.

BACKGROUND: Clinical and neuroimaging findings of glioblastomas (GBM) at an early stage have rarely been described and those tumors are most probably under-diagnosed. Furthermore, their genetic alterations, to our knowledge, have never been previously reported. METHODS: We report the clinical as well as neuroimaging findings of four early cases of patients with GBM. RESULTS: In our series, early stage GBM occurred at a mean age of 57 years. All patients had seizures as their first symptom. In all early stages, MRI showed a hyperintense signal on T2-weighted sequences and an enhancement on GdE-T1WI sequences. A hyperintense signal on diffusion sequences with a low ADC value was also found. These early observed occurrences of GBM developed rapidly and presented the MRI characteristics of classic GBM within a few weeks. The GBM size was multiplied by 32 in one month. Immunohistochemical analysis indicated the de novo nature of these tumors, i.e. absence of mutant IDH1 R132H protein expression, which is a diagnostic marker of low-grade diffuse glioma and secondary GBM. CONCLUSIONS: A better knowledge of early GBM presentation would allow a more suitable management of the patients and may improve their prognosis.

[Differential diagnosis of local tumor recurrence or radionecrosis after stereotactic radiosurgery for treatment of brain metastasis]. / Diagnostic différentiel entre récidive tumorale et radionécrose après radiothérapie stéréotaxique d'une métastase cérébrale.

Magnetic resonance imaging (MRI) is a method of choice for follow-up of irradiated brain metastasis. It is difficult to differentiate local tumour recurrences from radiation induced-changes in case of suspicious contrast enhancement. New advanced MRI techniques (perfusion and spectrometry) and amino acid positron-emission tomography (PET) allow to be more accurate and could avoid a stereotactic biopsy for histological assessment, the only reliable but invasive method. We report the case of a patient who underwent surgery for a single, left frontal brain metastasis of a breast carcinoma, followed by adjuvant stereotactic radiotherapy in the operative bed. Seven months after, she presented a local change in the irradiated area on the perfusion-weighted MRI, for which the differentiation between a local tumour recurrence and radionecrosis was not possible. PET with 2-deoxy-((18)F)-fluoro-D-glucose (FDG) revealed a hypermetabolic lesion. After surgical resection, the histological assessment has mainly recovered radionecrosis with few carcinoma cells. The multimodal MRI has greatly contributed to refine the differential diagnosis between tumour recurrence and radionecrosis, which remains difficult. The FDG PET is helpful, in favour of the diagnosis of local tumour recurrence when a hypermetabolic lesion is found. Others tracers (such as carbon 11 or a fluoride isotope) deserve interest but are not available in all centres. Stereotactic biopsy should be discussed if any doubt remains.

Bilateral semicircular canal aplasia.

INTRODUCTION: Bilateral semicircular canal aplasia is extremely rare; discovery, when the cochlear-vestibular system is normal and there is no hearing loss, is serendipitous. CASE REPORT: Bilateral semicircular canal aplasia was serendipitously discovered in a 24-year-old male during assessment of unilateral mixed hearing loss with subnormal contralateral hearing. The deformity was isolated, with no associated syndrome. DISCUSSION/CONCLUSION: Incidence of this isolated entity is unknown, but doubtless greatly underestimated due to the absence of associated symptomatology. To the best of our knowledge, this is only the second report of bilateral aplasia of the entire semicircular canal system involving unilateral hearing loss. A review of the literature focuses on the embryological and molecular aspects.

The Hospital Compare mortality model and the volume-outcome relationship.

OBJECTIVE: We ask whether Medicare's Hospital Compare random effects model correctly assesses acute myocardial infarction (AMI) hospital mortality rates when there is a volume-outcome relationship. DATA SOURCES/STUDY SETTING: Medicare claims on 208,157 AMI patients admitted in 3,629 acute care hospitals throughout the United States. STUDY DESIGN: We compared average-adjusted mortality using logistic regression with average adjusted mortality based on the Hospital Compare random effects model. We then fit random effects models with the same patient variables as in Medicare's Hospital Compare mortality model but also included terms for hospital Medicare AMI volume and another model that additionally included other hospital characteristics. PRINCIPAL FINDINGS: Hospital Compare's average adjusted mortality significantly underestimates average observed death rates in small volume hospitals. Placing hospital volume in the Hospital Compare model significantly improved predictions. CONCLUSIONS: The Hospital Compare random effects model underestimates the typically poorer performance of low-volume hospitals. Placing hospital volume in the Hospital Compare model, and possibly other important hospital characteristics, appears indicated when using a random effects model to predict outcomes. Care must be taken to insure the proper method of reporting such models, especially if hospital characteristics are included in the random effects model.

[Persistent stapedial artery with otosclerosis]. / Artère stapédienne persistante et ankylose stapédovestibulaire.

OBJECTIVES: A persistent stapedial artery is a rare vascular malformation. This diagnosis is based on CT scan and intraoperative findings. MATERIAL AND METHODS: The case of a 19-year-old woman with a persistent stapedial artery found during stapes surgery is reported. This vascular malformation was explored with a CT scan showing the bilaterality of this anatomical variation and signs of associated otosclerosis. RESULTS: This malformation was successfully coagulated with laser allowing the stapedotomy to be completed. CONCLUSIONS: A persistent stapedial artery is not a contraindication to stapedotomy because it can be safely coagulated during the same procedure.

An autopsy case of acute multiple sclerosis (Marburg's type) during pregnancy.

We report a case of a 9-month pregnant woman who presented acute psychiatric and neurological symptoms with extensive involvement of the white matter on MRI and no oligoclonal bands on CSF examination. Despite high doses of intravenous steroids, plasmapheresis and immunosuppressive drugs, a fatal outcome (coma) was noted 8 months later. Neuropathological examination confirmed the diagnosis of Marburg's type of multiple sclerosis showing sharp-edged lesions of demyelination, giant astrocytes, numerous macrophages and little perivascular inflammation. We discuss the definition and limits of the Marburg entity with reference to acute disseminated encephalomyelitis, impact of pregnancy, unusual MRI features, neuropathology and treatment.

[Conventional and diffusion magnetic resonance imaging in the acute phase of severe traumatic brain injury]. / Apports de l'IRM conventionnelle et de l'IRM de diffusion à la phase aiguë du traumatisme crânien grave.

Neuro-imaging is essential for the initial evaluation and subsequent control in the acute stage of severe head injury. In these indications tomodensitometry (TDM) has a pivotal role. Despite the well recognized contribution of magnetic resonance imaging (MRI) to the investigation of most of acute neurological pathologies, MRI is not still a routine procedure for the initial investigation of patients with acute head injury. The superiority of morphological and functional MRI on TDM in this indication is discussed.

Persistent carotid-vertebrobasilar anastomoses: how and why differentiating them?

The persistent carotid-vertebrobasilar anastomoses (PCVBA) can be explained by an interruption of the vertebrobasilar system (VBS) embryogenesis. We present two very rare cases of persistent anastomoses: a hypoglossal artery and a type I proatlantal artery, insisting on the angiographic criteria allowing differentiation. After a brief review of the embryogenesis of the VBS, we describe the different types of persistent anastomoses (hypoglossal, type I and II proatlantal, trigeminal and otic arteries). We will insist on the potential risks, not well-known, but typical of each anastomosis. PCVBA usually are incidental findings but imaging follow-up may be required since aneurysms may develop.

Radio-anatomic study of the pancreatic duct by MR cholangiopancreatography.

To compare the performance of MR-cholangiopancreatography (MRCP) and that of classical anatomy in the depiction of the main pancreatic duct, 50 MRCP examinations were done in patients free of pancreatic disease. Axial and coronal sections 20 mm thick were obtained in a Single Shot Fast Spin Echo (SSFSE) sequence. The following were analyzed: (1) visibility of pancreatic duct structures, (2) form of the main pancreatic duct, (3) various angulations of the duct and (4) diameter of the duct. Anatomic variants were noted. These findings were compared with anatomic and radio-anatomic (ERCP) data in the literature. The main pancreatic duct was visualized in 100% of cases and the accessory pancreatic duct in 61%. The form, diameter and angulations of the various segments of the pancreatic duct were similar to those reported in the literature. These findings are reported in the axial and coronal planes. Comparison with major anatomic classifications was not possible. MRCP enables in vivo anatomic exploration of the main pancreatic duct. Horizontal sections provided new radio-anatomic information. The technique nevertheless remains limited by poor spatial resolution.

Use of half-dose gadolinium-enhanced MRI and magnetization transfer saturation in brain tumors.

The aim of this study was to search if half-dose gadolinium (Gd)-enhanced MR imaging with magnetization transfer saturation (MT) can replace standard-dose T1-weighted spin echo (SE) without MT saturation in brain tumors. Thirty patients with a total of 33 brain tumors (14 gliomas, 13 meningiomas, 6 metastases) were prospectively studied using T1-weighted SE half-dose of Gd with MT, and T1-weighted SE standard-dose Gd without MT. The contrast-to-noise ratio (CNR) of the two sequences was calculated and four radiologists reviewed qualitatively the images of the two sequences. There was no significant difference between both techniques for quantitative analysis (Wilcoxon test). However, there was a good agreement between sequences to evidence an intraclass correlation coefficient (r = 0.70) of all lesions. In cases of meningioma, the agreement was better (r = 0.84). The results show a difference in the qualitative data between the two sequences, suggesting the use of the T1-weighted MR images with MT and half-dose of Gd with good results in the whole tested parameters except the lesional edema and the presence of artifacts. Half-dose T1-weighted SE with MT can replace standard-dose T1-weighted SE without MT with no loss of contrast enhancement in investigation of meningiomas and saving 50% of the contrast material.

Genomic and phenotypic characterization of Xanthomonas cynarae sp. nov., a new species that causes bacterial bract spot of artichoke (Cynara scolymus L.).

A bacterial disease of artichoke (Cynara scolymus L.) was first observed in 1954 in Brittany and the Loire Valley, France. This disease causes water-soaked spots on bracts and depreciates marketability of the harvest. Ten strains of the pathogen causing bacterial spot of artichoke, previously identified as a member of the genus Xanthomonas, were characterized and compared with type and pathotype strains of the 20 Xanthomonas species using a polyphasic study including both phenotypic and genomic methods. The ten strains presented general morphological, biochemical and physiological traits and G+C content characteristic of the genus Xanthomonas. Sequencing of the 165 rRNA gene confirmed that this bacterium belongs to the genus Xanthomonas, and more precisely to the Xanthomonas campestris core. DNA-DNA hybridization results showed that the strains that cause bacterial spot of artichoke were 92-100% related to the proposed type strain CFBP 4188T and constituted a discrete DNA homology group that was distinct from the 20 previously described Xanthomonas species. The results of numerical analysis were in accordance with DNA-DNA hybridization data. Strains causing the bacterial bract spot of artichoke exhibited consistent determinative biochemical characteristics, which distinguished them from the 20 other Xanthomonas species previously described. Furthermore, pathogenicity tests allowed specific identification of this new phytopathogenic bacterium. Thus, it is concluded that this bacterium is a new species belonging to the genus Xanthomonas, for which the name Xanthomonas cynarae is proposed. The type strain, CFBP 4188T, has been deposited in the Collection Française des Bactéries Phytopathogènes (CFBP).

New aromatase inhibitors. Synthesis and biological activity of aryl-substituted pyrrolizine and indolizine derivatives.

We report herein the design and the synthesis of some aryl-substituted pyrrolizine and indolizine derivatives, on the basis of a hypothetical pharmacophore structure designed to fit the catalytic site of the human cytochrome P450 aromatase. The in vitro biological evaluation of these compounds allowed us to point out two new potent non-steroidal aromatase inhibitors, MR 20494 and MR 20492, with IC50 values in the range of 0.1 microM.

Does high polyunsaturated free fatty acid level at the feto-maternal interface alter steroid hormone message during pregnancy?

Polyunsaturated fatty acids (PUFA) are important in pregnancy, fetal development and parturition. We measured free fatty acids (FFA), albumin and alpha-fetoprotein (AFP) in the maternal and fetal circulations of women undergoing elective Caesarean section at term. We also studied the impact of PUFAs on estrogen (ER) and progesterone receptors (PR) binding properties in vitro in the myometria of pregnant women and ex vivo in human myometrial cells in culture. FFA in intervillous blood (I) (feto-maternal interface) and maternal peripheral blood (M) were similar, while those in the umbilical vein (V) and arteries (A) were 2-4 fold lower (P<0.001). PUFA levels were low in M and 3 fold higher in I, A and V (P< 0.001); consequently C20:4 and C22:6 were most abundant in intervillous space. Albumin was uniformly distributed throughout the maternal-fetal unit, but there was a transplacental gradient in AFP. The AFP in the intervillous space had a special conformation (less immuno-reactive, more anionic), suggesting loading with PUFA. Physiological concentrations of C20:4 stimulated estradiol binding, but inhibited progestin binding. C20:4 inhibited progesterone binding by decreasing the number of binding sites, with no change in apparent affinity, in vitro in myometrial tissue and ex vivo in myometrial cells. Thus PUFA may modulate the steroid hormone message, so that the high C20:4 concentration at the maternal-fetal interface at term may help amplify the estrogen signal and inhibit the progesterone signal.

Anatomic and radioanatomic study of the lateral genicular arteries: application to prevention of postoperative hemarthrosis after arthroscopic lateral retinacular release.

Arthroscopic lateral retinacular release can be complicated by hemarthrosis in 10 to 18% of cases. The vascular structures involved are the lateral vascular pedicles of the knee. This study examines the topography of these pedicles. Anatomic and radioanatomic studies carried out in 50 specimens defined the route of the vascular pedicles at the lateral aspect of the knee. From the measurements carried out, we noted the relative homogeneity of the routes taken by the different proximo-lateral vascular pedicles, which are highly vulnerable, and the variability of the disto-lateral arterial routes. A tracing-paper study identified two distinct routes for the disto-lateral vascular pedicle and evaluated the risk of injury to it in surgical approaches to the lateral aspect of the knee. Finally, the topographic data of the study suggest the possibility of preventive hemostasis of the proximo-lateral pedicle via a minimal approach close to the patella. Furthermore, it seems possible to avoid cutting the disto-lateral pedicle if it is localised by cutaneous trans-illumination at the beginning of the operation.

Ultrasonographic diagnosis of hepatic fibrosis or cirrhosis.

BACKGROUND/AIMS: Evaluation of the degree of hepatic fibrosis is especially important in patients with chronic liver disease. Our aim was to study the diagnostic accuracy of abdominal ultrasonography for cirrhosis or fibrosis. METHODS: Twenty-three clinical (n=12) and Doppler ultrasonic (n=11) variables were recorded in 243 patients with chronic (alcoholic and viral) liver disease under conditions close to those of clinical practice. Fibrosis was classified into six grades by two pathologists. Diagnostic accuracy was evaluated by discriminant analysis, first globally using all variables, then by stepwise analysis. RESULTS: A) Diagnosis of cirrhosis: 1) whole group (n=243): diagnostic accuracy was globally 84%, and 84% with two variables: spleen length, portal velocity; 2) compensated chronic liver disease (n=191): diagnostic accuracy was globally 85%, and 82% with two variables: liver surface, liver length (right kidney); 3) alcoholic compensated chronic liver disease (n=109): diagnostic accuracy was globally 86%, and 88% with two variables: spleen length, liver length (middle clavicle); 4) viral compensated chronic liver disease (n= 83): diagnostic accuracy was globally 86% and 86% with one variable: liver surface. By subtracting the proportion of patients who could not be investigated due to anatomical limitations, the highest calculated univariate diagnostic accuracy decreased by 7%. B) Diagnosis of fibrosis: diagnostic accuracy was globally 84% for extensive fibrosis. CONCLUSIONS: Cirrhosis can be correctly diagnosed in 82-88% of patients with chronic liver disease using a few ultrasonographic signs. However, the diagnostic accuracy of ultrasound is decreased by the anatomical limitations of this technique.

[Cervical deficit radiculopathy in 3 cases of vertebral artery dissection]. / Radiculopathie cervicale déficitaire au cours de trois cas de dissection de l'artère vertébrale.

Three cases of extracranial vertebral artery dissections with upper limb peripheral motor deficit (C5-C6) are reported. Six similar cases were also found in the literature. Central neurological symptoms occurred in five of these nine cases, suggesting the diagnosis of dissection. The peripheral motor or sensorial deficit was strictly isolated in the four other cases, simulating radicular neuralgia due to discopathy or foraminal compression. In case of dissections, a precise analysis of pain is helpful to guide diagnosis; sharp, unbearable, continuous and extended neck pain without nocturnal paroxysms and posterior neck stiffness is typical. Analgesics or anti-inflammatory drugs are ineffective. Peripheral motor deficit is more common than sensory deficit. Recovery was complete in this series. In most cases, the radiculopathy appears to be due to cervical root compression in its extraforaminal course due to the dissection hematoma and rarely to radicular ischemia.

Halothane acts as a partial agonist of the alpha6 beta2 gamma2S GABA(A)receptor.

Whole-cell patch clamp recording was performed on human embryonic kidney 293 cells stably transfected with rat cDNAs for the alpha6, beta2, and gamma2S subunits of the GABA(A) receptor. The volatile anesthetic halothane directly activated a current in the absence of the ligand gamma-aminobutyric acid (GABA). Both the current amplitude and the rate of desensitization increased in a dose-dependent manner with an EC50 of 1.0+/-0.2 mM and a Hill coefficient (nh) of 1.5+/-0.1. The EC50 and nh for GABA to activate the receptor were 1.0+/-0.3 microM and 1.4+/-0.2, respectively. The peak amplitude of the halothane-activated current was about 4% of the maximal GABA response, which was not changed when the concentration of Ca2+ in the external solution was decreased from 2 mM to 0.2 mM. The reversal potential of both halothane- and GABA-activated currents changed with the external Cl- concentration as predicted by the Nernst equation for chloride ions. The halothane- and GABA-activated currents were blocked by both the noncompetitive GABA(A) receptor antagonist picrotoxin and the competitive GABA(A) receptor antagonist bicuculline. Schild plots revealed that the K(i)s for bicuculline to competitively antagonize the currents activated by halothane and GABA are similar (0.69 and 0.72 microM, respectively). These results indicate that halothane activates the alpha6 beta2 gamma2S GABA(A) receptor to induce a current similar to the GABA-induced current.

First report of the inhibition of arbuscular mycorrhizal infection of Pisum sativum by specific and irreversible inhibition of polyamine biosynthesis or by gibberellic acid treatment.

DFMO (alpha-DL-difluoromethylornithine), a specific irreversible inhibitor of ornithine decarboxylase (ODC), a polyamine biosynthetic pathway enzyme, strongly inhibits root growth and arbuscular mycorrhizal infection of Pisum sativum (P56 myc+, isogenic mutant of cv. Frisson). This inhibition is reversed when exogenous polyamine (putrescine) is included in the DFMO treatment, showing that the effect of DFMO on arbuscular mycorrhizal infection is indeed due to putrescine limitation and suggesting that ODC may have a role in root growth and mycorrhizal infection. However, treatment with gibberellic acid (GA3) which increased root titers of polyamines strongly inhibited arbuscular mycorrhizal development. The possible role of polyamines in the regulation of the development of arbuscular mycorrhizal infection is discussed.