mantisGRID: A Grid Platform for DICOM Medical Images Management in Colombia and Latin America

This paper presents the mantisGRID project, an interinstitutional initiative from Colombian medical and academic centers aiming to provide medical grid services for Colombia and Latin America. The mantisGRID is a GRID platform, based on open source grid infrastructure that provides the necessary services to access and exchange medical images and associated information following digital imaging and communications in medicine (DICOM) and health level 7 standards. The paper focuses first on the data abstraction architecture, which is achieved via Open Grid Services Architecture Data Access and Integration (OGSA-DAI) services and supported by the Globus Toolkit. The grid currently uses a 30-Mb bandwidth of the Colombian High Technology Academic Network, RENATA, connected to Internet 2. It also includes a discussion on the relational database created to handle the DICOM objects that were represented using Extensible Markup Language Schema documents, as well as other features implemented such as data security, user authentication, and patient confidentiality. Grid performance was tested using the three current operative nodes and the results demonstrated comparable query times between the mantisGRID (OGSA-DAI) and Distributed mySQL databases, especially for a large number of records.     

Diagnostic utility of a multiplex herpesvirus PCR assay performed with cerebrospinal fluid from human immunodeficiency virus-infected patients with neurological disorders

We used a multiplex nested-PCR assay for the simultaneous detection in cerebrospinal fluid (CSF) of five human herpesviruses (HVs) (cytomegalovirus [CMV], Epstein-Barr virus [EBV], varicella-zoster virus [VZV], herpes simplex virus [HSV], and human herpesvirus 6 [HHV-6]) in a clinical evaluation of human immunodeficiency virus (HIV)-infected patients with neurological disorders. This method, which has the advantages of being rapid and economical, would be of particular interest for the diagnosis of neurological syndromes caused by more than one HV. We studied 251 CSF samples from 219 patients. HV DNA was demonstrated in 93 (37%) of the CSF samples (34% of the patients). CMV was the HV most frequently detected in our patients (25%), while EBV, VZV, HSV, and HHV-6 DNAs were present in significantly fewer cases (7, 4, 3, and 1%, respectively). When results were compared with the final etiological diagnoses of the patients, the multiplex HV PCR showed high specificity for the diagnosis of CMV and VZV neurological diseases and for cerebral lymphoma (0.95, 0.97, and 0.99, respectively). The sensitivity of the assay was high for CMV disease (0.87), was low for cerebral lymphoma (0.33), and was not evaluable for VZV disease due to the small number of patients with this diagnosis. Nevertheless, detection of VZV DNA had possible diagnostic value in four of the nine cases, and EBV DNA amplification always predicted the diagnosis of cerebral lymphoma in patients with cerebral masses. Detection of HSV DNA was frequently associated with CMV amplification and fatal encephalitis. HHV-6 was not considered to have a pathogenetic role in the three cases in which it was detected. This multiplex HV PCR assay is a specific and clinically useful method for the evaluation of HIV-infected patients with neurological disorders related to HV.     

The effect of supplemental copper on osteopenia induced by ovariectomy in rats

OBJECTIVE: The effect of a copper supplement on preventing bone mass loss induced by ovariectomy in rats was investigated. DESIGN: Three groups of fifteen 100-day-old female Wistar rats, each with a mean initial weight of approximately 260 g per animal, were selected for a 30-day experiment. One group of 15 ovariectomized rats was fed a diet supplemented with 15 mg of copper per kilogram of feed. The other two groups: 15 ovariectomized and 15 Sham- ovariectomized rats did not receive the supplement. Morphometric (weight and length) and densitometric studies with dual-energy x-ray absorptiometry were performed on the whole femur and the fifth lumbar vertebra of each animal at the end of the 30-day period. RESULTS: The ovariectomized rat group fed a diet supplemented with copper did not show the bone mass loss at the axial (fifth lumbar vertebra) or peripheral (femur) level that was evidenced in the ovariectomized group. CONCLUSIONS: The results of the measurement of axial and peripheral bones show that a supplement of copper may have a potential therapeutic application in the treatment and prevention of involutional osteoporosis.     

Calcium and phosphorus contents of body parts of some domestic animals used as meat source in Nigeria

ObjectiveTo investigate the calcium and phosphorus contents of four domestic animals used as sources of meat in Nigeria.MethodsThe calcium contents of the body parts of the animals were determined using atomic absorption spectrometer. Their phosphorus contents were determined colorimetrically using the molybdenum blue method.ResultsThe calcium and phosphorus contents were significantly higher in the bone samples than in the other animal parts investigated (P<0.05). The calcium contents of all the edible parts were higher in chicken than in the other animals. High calcium and phosphorus contents were detected in the faeces of chicken and goat, and that of cattle and goat, respectively. Low calcium and phosphorus contents were detected in the urine samples. Calcium: phosphorus ratios calculated for the bones of chicken, cattle and goat were satisfactory.ConclusionsIn conclusion, calcium and phosphorus contents of the animal parts vary significantly and their relative contents may be related to the animal's diet. Chicken parts may be the preferred dietary source of these minerals. This study highlights the need for routine investigation of the mineral contents of food, which is necessary for proper nutritional guidelines.     

Validation of a 7-day physical activity diary against doubly-labelled water

Background: The assessment of physical activity intensity and duration is essential for understanding group activity patterns.

Methods: The present study evaluated the validity of measurement of total energy expenditure (TEE) and physical activity level (PAL) using a categorized physical activity diary. In 29 young healthy men, aged 18–27 years, with body mass index range 21–43 kg m^?2, TEE using doubly-labelled water (DLW), resting metabolic rate (RMR) by indirect calorimetry, physical activity level (PAL defined as TEE/RMR) and activity pattern, timing and level from 7-day physical activity diaries were determined.

Results: TEE by DLW and estimated by activity diary were correlated (r?=?0.61, p?=?0.005). The mean underestimation of TEE by the activity diary compared with the DLW method was 2.50?±?0.72 MJ day^?1. Sedentary (lying, sitting and standing) time averaged 18 h day^?1 and was negatively correlated with PAL (r?=??0.44, p?=?0.018) whilst time spent in light intensity activity (5 h day^?1) was positively correlated (r?=?0.51, p?=?0.005).

Conclusions: It is concluded that the categorized physical activity diary measured TEE with limited accuracy but presents an inexpensive, convenient method of discriminating individual and group physical activity patterns.     

High microvessel density in pancreatic ductal adenocarcinoma is associated with high grade

The objectives of this work are to study angiogenesis in pancreatic ductal adenocarcinoma using computerized morphometric and image analysis and to compare the microvascular density in intratumoral and peritumoral areas and normal pancreatic tissue. Microvascular density was analyzed in 60 cases of pancreatic ductal adenocarcinoma and 30 samples of normal pancreatic tissue using an avidin–biotin immunoperoxidase technique with an anti-CD31 antibody. Microvascular density (MVD) was analyzed through digital microimaging and computerized analysis. The blood vessel density in the tumor was significantly higher than in peritumoral areas and in normal pancreatic tissue. Well differentiated pancreatic ductal adenocarcinomas contained higher MVD than poorly differentiated carcinomas. In pancreatic adenocarcinoma, MVD is higher than in peritumoral tissue or normal pancreatic tissue.     

The standard error of measurement is a more appropriate measure of quality for postgraduate medical assessments than is reliability: an analysis of MRCP(UK) examinations

Background  

Cronbach's alpha is widely used as the preferred index of reliability for medical postgraduate examinations. A value of 0.8-0.9 is seen by providers and regulators alike as an adequate demonstration of acceptable reliability for any assessment. Of the other statistical parameters, Standard Error of Measurement (SEM) is mainly seen as useful only in determining the accuracy of a pass mark. However the alpha coefficient depends both on SEM and on the ability range (standard deviation, SD) of candidates taking an exam. This study investigated the extent to which the necessarily narrower ability range in candidates taking the second of the three part MRCP(UK) diploma examinations, biases assessment of reliability and SEM.     

Bruxism in children: effect on sleep architecture and daytime cognitive performance and behavior

STUDY OBJECTIVES: Sleep bruxism is an involuntary mandibular movement with tooth grinding during sleep. The prevalence of sleep bruxism in children is high and may lead to frequent arousals with altered daytime functioning. We investigated the sleep architecture, the incidence of gastroesophageal reflux, and the daytime cognitive behavioral functioning in a group of children with sleep bruxism. DESIGN-PATIENTS: This prospective pilot study included 10 children. Polysomnographic data with pH-probe analysis was compared with 10 age- and sex-matched controls. Each patient completed a dental evaluation, a nighttime polysomnogram, and cognitive behavioral tests (Kaufman Brief Intelligence Test and Achenbach Child Behavior Checklist). RESULTS: Eight of 10 children had clinically significant bruxism and the 2 remaining patients had recent teeth exfoliation. There was no difference on sleep architecture between patients and controls, except for a higher arousal index for the bruxism group (36.7 vs 20.7, p < .007). Sleep bruxism occurred more frequently in stage 2 and rapid eye movement sleep, with arousals in 66% of the cases. There was no relationship of bruxism to gastroesophageal reflux or intelligence. However, 40% of the patients had elevated scores on the Achenbach Child Behavior Checklist, indicating significant attention and behavior problems, and there were moderate correlations between the arousal index and several of the behavior-problem scales from the Achenbach Child Behavior Checklist (0.5 to 0.6). CONCLUSIONS: The data suggest that children with bruxism have a higher arousal index, which may be associated with an increased incidence of attention-behavior problems. Future studies investigating pediatric sleep bruxism will need to focus on behavior issues that may be prevalent in this population.