Automated segmentation of the aorta from phase contrast MR images: Validation against expert tracing in healthy volunteers and in patients with a dilated aorta

Purpose:

To assess if segmentation of the aorta can be accurately achieved using the modulus image of phase contrast (PC) magnetic resonance (MR) acquisitions.

Materials and Methods:

PC image sequences containing both the ascending and descending aorta of 52 subjects were acquired using three different MR scanners. An automated segmentation technique, based on a 2D+t deformable surface that takes into account the features of PC aortic images, such as flow‐related effects, was developed. The study was designed to: 1) assess the variability of our approach and its robustness to the type of MR scanner, and 2) determine its sensitivity to aortic dilation and its accuracy against an expert manual tracing.

Results:

Interobserver variability in the lumen area was 0.59 ± 0.92% for the automated approach versus 10.09 ± 8.29% for manual segmentation. The mean Dice overlap measure was 0.945 ± 0.014. The method was robust to the aortic size and highly correlated (r = 0.99) with the manual tracing in terms of aortic area and diameter.

Conclusion:

A fast and robust automated segmentation of the aortic lumen was developed and successfully tested on images provided by various MR scanners and acquired on healthy volunteers as well as on patients with a dilated aorta. J. Magn. Reson. Imaging 2010;31:881–888. ©2010 Wiley‐Liss, Inc.     

Incidence of Hepatitis C Virus (HCV), Hepatitis B Virus (HBV) and Dual Infection in Egyptian Patients on Haemodialysis

Hepatitis viral infections are important causes of morbidity and mortality in haemodialysis patients. The aim of the present work is to study the prevalence and possible risk factors of hepatitis C virus (HCV), hepatitis B virus (HBV) and dual infection in haemodialysis patients. Three hundred forty patients with end-stage renal disease, 266 males (78.2%) with mean age of 50.9?±?11.6 years and 74 females (21.8%) with mean age of 53.5?±?10.5 years on haemodialysis, were recruited from four haemodialysis units. They were screened for the presence of HCV, HBV and dual HCV and HBV infections and possible risk factors for acquiring these infections in those patients during the period between June 2007 and August 2009. One hundred ninety-six (57.7%) patients were HCV positive while 12 (3.5%) patients had HBV infection. A dual infection with both viruses was observed in 26 patients (7.6%).There was a significant difference in the number of blood transfusions among HCV-positive, HBV-positive and dual infection patients and negative patients (12.4?±?7.6, 13.8?±?6.8, 13.5?±?8.3 vs. 5.2?±?3.4 transfusions, p?<?0.01). HCV, HBV and dual HCV and HBV patients have been on dialysis for a longer period than the negative patients (7.5?±?5, 6.2?±?3.6, 7.5?±?5.4 vs. 4.4?±?4 years, p?<?0.01). Higher HCV was associated with longer haemodialysis duration and history of previous blood transfusion and not associated with dialysis in multicentres. HBV and dual infection is less prevalent than HCV in haemodialysis units.     

Comparison of the postprandial release of peptide YY and proglucagon-derived peptides in the rat

Endocrine L-cells of the distal intestine synthesize both peptide YY (PYY) and proglucagon-derived peptides (PGDPs), whose release has been reported to be either parallel or selective. Here we compare the release mechanisms of PYY, glucagon-like peptide-1 (GLP-1), and oxyntomodulin-like immunoreactivity (OLI) in vivo. Anaesthetized rats were intraduodenally (ID) given either a mixed semi-liquid meal or oleic acid, or they received oleic acid or short chain fatty acids (SCFA) intracolonically (IC). The ID meal released the three peptides with a similar time-course (peak at 30 min); ID oleic acid produced a progressive release of PYY and OLI, while GLP-1 release was less. IC oleic acid or SCFA released smaller (but significant) amounts of PYY but no OLI or GLP-1. Hexamethonium inhibited most of the response to the ID meal and ID oleic acid, but did not change the PYY response to IC oleic acid. N ^G -nitro-l-arginine methyl ester (l-NAME, a nitric oxide synthase inhibitor) inhibited meal-induced PYY release and left OLI and GLP-1 unaffected. BW10 (a gastrin-releasing peptide antagonist) had no effect on the meal-induced release of either peptide. These results suggest a parallel initial release of PYY, OLI and GLP-1 after the ID meal, or oleic acid, by an indirect mechanism triggered in the proximal bowel, using nicotinic synapses, and involving nitric oxide release for PYY and an unknown mediator for PGDPs. For PYY there is a later phase of peptide release, probably induced by direct contact between nutrients and colonic L-cells. Received: 8 January 1999 / Received after revision: 25 March 1999 / Accepted: 26 April 1999     

Distribution of HLA-B27 and its alleles in patients with reactive arthritis and with ankylosing spondylitis in Tunisia

The purpose of the present study is to investigate the frequency of HLA-B27 and its alleles in reactive arthritis (ReA) and in ankylosing spondylitis (AS) in Tunisia. HLA-B27 alleles were typed by PCR amplification with sequence-specific primers. We studied 17 patients with ReA associated with urethritis or with gastrointestinal infection; 42 HLA-B27-positive patients with AS and 100 healthy controls. Eleven ReA patients (67.7%) were HLA-B27 positive. There was an increased frequencies of HLA-B27 (P = 7.76 × 10⁻¹², OR = 59.30) and a moderate increase of HLA-B51 (P = 0.015; OR = 4.91) alleles in ReA patients when compared with healthy controls. Four B27 subtypes were identified: B*2702, 05, 09 and B*2712. The distribution of these alleles in the ReA patients was 37.5% for B*2702 and B*2705. Only these two subtypes were detected in 18 (42.8%) and 24 (57.1%), respectively, of the AS patients. B*2709 and B*2712 were relatively rare in ReA patients and were identified in one case each. Our results showed a restricted number of HLA-B27 subtypes associated with ReA and AS. B*2702 and 2705 were common in ReA and AS patients.     

Shopping for nutrition-based complementary and alternative medicine on the internet: How much money might cancer patients be spending online?

Background. How much money might cancer patients be spending on-line for nutrition-based complementary and alternative medicine therapies? This question is relevant because over $34 billion per year is spent on complementary and alternative medicine in the United States, and the Internet has facilitated the acquisition of such therapies.Methods. We therefore conducted a “patient simulation exercise” in which the Internet was surfed for nutrition-based therapies, which were touted as therapeutic or palliative in the cancer setting. Monthly costs for each agent were calculated. Agents with clinical evidence of efficacy were excluded.Results. A search of 2,500 Web sites and related pages revealed a total of 16 different products. The monthly cost of each ranged from to $4.33 to $263.00. The median cost of a single agent was $27.00 per month.Conclusions. This study emphasizes the need for health care providers to undertake with cancer patients a comprehensive discussion of therapeutic options—including those relevant to nutrition-based complementary and alternative medicine. A compassionate discussion of patients’ out-of-pocket costs should be an integral part of that discussion and should be emphasized as an important dimension of patient education efforts.     

Synthesis and structure-activity relationships of novel arylalkyl 4-benzyl piperazine derivatives as sigma site selective ligands

Continuing our previous work that established that some chromones substituted by an aryl alkyl piperazino alkyl side chain are potent and selective sigma ligands and could be interesting in the treatment of psychosis, we synthesized 60 new compounds, replacing the chromone moiety by various cyclic systems. Many derivatives bind to the sigma sites in the nanomolar range and are generally selective in comparison with 5HT(1A) and the D(2) receptors. One of the most potent ligands of these series, 1-(2-naphthyl methyl)-4-benzyl piperazine 29, has been studied in various pharmacological tests. Although it doesn't have potential in the treatment of psychosis, the results we obtained confirm the data which indicates that such derivatives could be interesting in the treatment of inflammatory diseases.     

Role of circulating complement and polymorphonuclear leukocyte transfusion in treatment and outcome in critically ill neonates with sepsis

We examined the effects of early administration of polymorphonuclear leukocyte (PMN) transfusions in neonates with sepsis by prospectively randomizing 35 consecutive critically ill infants with sepsis, 21 of whom received PMN transfusions in addition to supportive care, one transfusion every 12 hours for a total of five transfusions. Each transfusion consisted of 15 mL/kg containing 0.5 to 1.0 X 10(9) PMN with less than 10% lymphocytes, and was subjected to 1500 rads. PMNs were obtained by continuous-flow centrifugation leukopheresis. Pretreatment values that did not significantly affect survival included weight, gestational age, sex, prematurity, C-reactive protein, initial hematocrit, platelet count and absolute granulocyte count (AGC less than or equal to 1500/mm3), IgM, IgG, IgA, neutrophil supply pool depletion, hypoxia, acidosis, and hypotension. Postnatal age was significantly lower in the nontransfused group than in the transfused group; 2.3 +/- 0.6 vs 6.1 +/- 2.2, (P less than 0.001). Positive blood cultures were obtained in 80% of both groups. Low circulating levels of total hemolytic complement were associated with a poor outcome and higher mortality: 56 +/- 4.0 IU in survivors vs 31 +/- 4.4 IU in nonsurvivors (P less than 0.01). Survival was significantly greater in the PMN transfused group than in the nontransfused group: 20 (95%) of 21 vs nine (64%) of 14 (P less than or equal to 0.05). No untoward effects were attributable to PMN transfusions, either during the study or on subsequent follow-up visits. These preliminary data suggest that early treatment with PMN transfusions improves survival in neonates with overwhelming sepsis. In addition, depleted or low circulating levels of complement may influence prognosis and thus future treatment strategies for neonatal sepsis.