Comparison of visual and ROI-based brain tumour grading using 18F-FDG PET: ROC analyses

Several studies have suggested that the use of simple visual interpretation criteria for the investigation of brain tumours by positron emission tomography with fluorine-18 fluorodeoxyglucose (FDG-PET) might be similarly or even more accurate than quantitative or semi-quantitative approaches. We investigated this hypothesis by comparing the accuracy of FDG-PET brain tumour grading using a proposed six-step visual grading scale (VGS; applied by three independent observers unaware of the clinical history and the results of histopathology) and three different region of interest (ROI) ratios (maximal tumour uptake compared with contralateral tissue [Tu/Tis], grey matter [Tu/GM] and white matter [Tu/WM]). The patient population comprised 47 patients suffering from 17 benign (7 gliomas of grade II, 10 non-gliomatous tumours) and 30 malignant (23 gliomas of grade III-IV, 7 non-gliomatous tumours) tumours. The VGS results were highly correlated with the different ROI ratios (R=0.91 for Tu/GM, R=0.82 for Tu/WM, and R=0.79 for Tu/Tis), and high inter-observer agreement was achieved (kappa=0.63, 0.76 and 0.81 for the three observers). The mean ROI ratios and VGS readings of gliomatous and non-gliomatous lesions were not significantly different. For all measures, high-grade lesions showed significantly higher FDG uptake than low-grade lesions (P<0.005 to P<0.0001, depending on the measure used). Nominal logistic regressions and receiver operating characteristic (ROC) analyses were used to calculate cut-off values to differentiate low- from high-grade lesions. The predicted (by ROC) diagnostic sensitivity/specificity of the different tests (cut-off ratios shown in parentheses) were: Tu/GM: 0.87/0.85 (0.7), Tu/WM: 0.93/0.80 (1.3). Tu/Tis: 0.80/0.80 (0.8) and VGS: 0.84/0.95 (uptake < GM, but > WM). The VGS yielded the highest Az (+/-SE) value (i.e. area under the ROC curve as a measure of predicted accuracy), 0.97+/-0.03, which showed a strong tendency towards being significantly greater than the Az of Tu/Tis (0.88+/-0.06; P=0.06). Tu/GM (0.92+/-0.04) and Tu/WM (0.91+/-0.05) reached intermediate Az values (not significantly different from any other value). We conclude that the VGS represents a measure at least as accurate as the Tu/GM and Tu/WM ratios. The Tu/Tis ratio is less valid owing to the high dependence on the location of the lesion. Depending on the investigator's experience and the structure of the lesions, the easily used VGS might be the most favourable grading criterion.     

An update on myasthenic crisis

Opinion statement Myasthenia gravis (MG) is the most common disorder of the neuromuscular junction. Myasthenia crisis, defined as respiratory failure requiring mechanical ventilation in MG, is a common life-threatening complication that occurs in approximately 15% to 20% of patients with MG during their life time. The advent of effective mechanical ventilation, specialized neurointensive care units and the widespread use of immunotherapies have substantially altered the prognosis of myasthenic crisis. Early intubation and mechanical ventilation is perhaps the most important step in the management of myasthenic crisis. The authors favor an orotracheal approach for intubation, and placement of small bore duodenal tubes that may help decrease the risk of aspiration and may be more comfortable than regular nasogastric tubes for the patient. Plasma exchange may be more effective than the intravenous immunoglobulin in the treatment of myasthenic crisis involving respiratory failure. A randomized trial is required to confirm the superior efficacy of plasma exchange compared with intravenous immunoglobulin. In the acute setting, the role of immunosuppression and intravenous/intramuscular pyridostigmine and the newer agents such as tacrolimus remains limited and at times controversial. The therapy should be tailored at an individual basis using best clinical judgment.     

Tuberculosis of the greater trochanter: a report of three cases

Trochanteric tuberculosis represents less than 2% of all musculo-skeletal tuberculosis. The diagnosis is difficult especially if abscess and fistula are missing. The authors report 3 cases of trochanteric tuberculosis. The diagnosis was established, respectively, 4, 9 months and 1 year after the beginning of the symptoms. The tuberculosis was plurifocal in all cases. Diagnosis was based on the presence of caseum granuloma in the first case, positive Lowenstein culture in the second case and on clinical and paraclinical arguments in the third one. Healing was obtained after medical treatment alone. The authors discuss the potential role of the newer imaging modalities in diagnosis of trochanteric tuberculosis and the indications of medical and surgical treatment.     

Mucosal immunization of sheep with a Maedi-Visna virus (MVV) env DNA vaccine protects against early MVV productive infection

Gene gun mucosal DNA immunization of sheep with a plasmid expressing the env gene of Maedi-Visna virus (MVV) was used to examine the protection against MVV infection in sheep from a naturally infected flock. For immunization, sheep were primed with a pcDNA plasmid (pcDNA-env) encoding the Env glycoproteins of MVV and boosted with combined pcDNA-env and pCR3.1-IFN-gamma plasmid inoculations. The pcDNA plasmid used in the control group contained the lacZ coding sequences instead of the env gene. Within a month post-challenge, the viral load in the vaccinated group was lower (p < or = 0.05) and virus was only detected transiently compared with the control group. Furthermore, 2 months later, neutralizing antibodies (NtAb) were detected in all the control animals and none of the vaccinated animals (p < or = 0.01). These results demonstrated a significant early protective effect of this immunization strategy against MVV infection that restricts the virus replication following challenge in the absence of NtAb production. This vaccine protective effect against MVV infection disappeared after two years post-challenge, when active replication of MVV challenge strain was observed. Protection conferred by the vaccine could not be explained by OLA DRB1 allele or genotype differences. Most of the individuals were DRB1 heterozygous and none was totally resistant to infection.     

Surgical importance of highly located innominate artery in neck surgery

Massive hemorrhage is an unusual complication of tracheotomy, and the most common causes are injury to the anterior jugular veins and the thyroid isthmus, or unrecognized variations of the vascular structures, such as the arteria thyroidea ima. We present a case of high-running innominate artery that ascends until the third tracheal ring and courses horizontally anterior to the trachea in a patient with laryngeal carcinoma. If not noticed during tracheolaryngeal surgery, trauma to this vessel and subsequent hemorrhage may be fatal. In this report, the case is presented and the surgical significance of this anomaly is emphasized.     

Preliminary investigation of the feasibility of magnetic propulsion for future microdevices in blood vessels

The Magnetic Resonance Submarine (MR-Sub) project is a first attempt to validate a new propulsion method for future small magnetically controlled microdevices suited for minimally invasive applications in blood vessels. A Magnetic Resonance Imaging (MRI) system provides the driving force in three dimensions to a ferromagnetic core that could be embedded onto a specialised microdevice. The paper describes preliminary tests made to match the magnetic force induced by an MRI system on a ferromagnetic sphere with the drag force it encompasses in a cylindrical tube. These tests provide a proof of concept demonstrating that this new method of propulsion is very promising within the constraints of such types of operations. This conclusion is based on specific measurements showing that 1010/1020 carbon steel spheres (3.175 mm and 2.381 mm in diameter) can withstand a maximum flow of 0.370 +/- 0.0064 l/min (19.5 cm/s) and 0.311 +/- 0.01209 l/min (16.4 cm/s) respectively when placed inside a 6.35 mm diameter PMMA tube and subjected to a 18 mT/m magnetic field gradient.     

Effects of combined treatment on Turkish children diagnosed with attention-deficit/hyperactivity disorder: a preliminary report

OBJECTIVE: The main aim of this study was to investigate the effects of combined treatment on children diagnosed with attention-deficit/hyperactivity disorder (ADHD). METHOD: After careful screening, 47 children (57%) diagnosed with ADHD + oppositional defiant disorder (ODD) and 36 children (43%) diagnosed with ADHD + conduct disorder (CD) were included in the study. Treatment consisted of ongoing medication (methylphenidate) management and a parent-training program that continued for 5 months. Children were assessed in multiple domains by multiple sources of information at baseline and at the end of the 1st, 3rd, and 6th months by parent- and teacher-completed the Turgay Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV)-Based Child and Adolescent Behavior Disorders Screening and Rating Scale (T-DSM-IV-S), Conners Parent Rating Scale (CPRS), and Conners Teacher Rating Scale (CTRS). Mother-child relationship was assessed by the Parental Acceptance and Rejection Questionnaire (PARQ). RESULTS: Combined treatment was effective in reducing the ADHD, ODD, and CD symptoms. Analyses of the data revealed that medication, rather than parent training, was responsible for the improvements both in the symptoms and in the mother-child relationship. CONCLUSIONS: The results of the study, in line with the Multimodal Treatment Study of Children with ADHD (MTA) findings, highlighted the role of stimulant medication in the treatment of ADHD.