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.     

Association of cell-free plasma DNA with perioperative mortality in patients with suspected acute mesenteric ischemia

BackgroundDiagnosing patients with acute mesenteric ischemia (AMI) in the emergency ward is challenging. This study assesses the usefulness of plasma DNA in patients with clinically suspected AMI.Methods130 consecutive patients who underwent laparotomy were studied. Cell-free plasma DNA was measured by real-time quantitative PCR assay for the β-globin gene. The primary endpoint was the accuracy of plasma DNA for predicting 30-day mortality.ResultsSurgery revealed AMI in 99 patients and alternative diagnoses in 31 patients. Forty-six patients with AMI died (46.6%) as compared to 6 (19.4%) in the non-AMI group (p < 0.05). The DNA concentration at admission was significantly higher in patients with AMI (median 7340 GE/ml, versus, 2735 GE/ml, p < 0.01) and in AMI patients who died (8830 GE/ml, versus 4970 GE/ml, p < 0.05). The area under the ROC curves for plasma DNA as a marker for mesenteric ischemia and independent predictor for 30-day mortality were 0.708 (95% CI 0.701–0.890) and 0.815 (95% CI 0.735–0.894). Multiple logistic regression analysis showed that the risk of hospital mortality increased 1.52-fold for every 1000 GE/ml increase in plasma DNA.ConclusionsPlasma DNA levels may be a useful biomarker in predicting the outcome of patients with AMI.     

Clinical trial of home available, mixed diets versus a lactose-free, soy-protein formula for the dietary management of acute childhood diarrhea

A randomized clinical trial was completed to study the severity, duration, and nutritional outcome of acute diarrhea in 85 Peruvian children between 5 and 24 months of age who received a soy-protein-isolate, lactose-free formula (group SF) or one of two mixtures of home-available foods, all in amounts up to 110 kcal/kg of body weight/day. The mixed diets contained either wheat flour, pea flour, carrot flour, sucrose, and vegetable oil (group WP) or potato flour, dried whole milk, carrot flour, sucrose, and oil (group PM). The characteristics of the children in each group were generally similar initially. There were no differences in treatment failure rate by diet group. Fecal outputs were similar in all groups during the first day of treatment, averaging 60 to 65 g/kg/day. However, stool outputs were greater for the PM group than for other groups on days 3 and 4, and were less for the SF group than the other groups on days 5 and 6. The estimated median durations of diarrhea in the WP group (52 h) and PM group (53 h) were significantly less than in the SF group (154 h, p = 0.005). Energy intakes, energy absorption, and nitrogen retention (% of intake) were generally similar in all dietary groups, although there were minor differences in the absorption of specific macronutrients. Children in all groups gained weight during hospitalization, and there were no significant differences by diet group in the change in anthropometric status during treatment. We conclude that these locally available, low-cost staple food mixtures offer a safe and nutritionally adequate alternative to a commercially produced lactose-free formula for the dietary management of young children with acute diarrhea in this setting.     

Air bag-induced corneal flap folds after laser in situ keratomileusis

PURPOSE: We describe a case of air bag-induced ocular trauma resulting in folds in the corneal flap 3 weeks after laser in situ keratomileusis. METHODS: Case report. Three weeks after laser in situ keratomileusis, a 20-year-old man was involved in a motor vehicle accident and sustained blunt trauma to the right eye, which caused corneal flap folds, corneal edema, anterior chamber cellular reaction, and Berlin retinal edema. RESULTS: Six weeks after laser in situ keratomileusis, persistent flap folds necessitated re-operation with lifting of the flap and repositioning. One week after the procedure, the visual acuity improved to 20/20-2, and the folds had cleared. CONCLUSION: Trauma after laser in situ keratomileusis may produce folds in the corneal flap. With persistence of these folds, management by lifting and repositioning the corneal flap may be necessary to permit recovery of visual acuity.     

Intraventricular hemorrhage in the newborn infant at term: thalamic origin

Four observations of intraventricular hemorrhage in full term neonates without perinatal asphyxia are reported. The clinical pictures were remarkably similar in the four infants: neurological symptoms developed several days after birth with sunsetting and eye deviation and symptoms of cranial hypertension. Ultrasonography and CT scan showed a thalamic hemorrhage.     

Anticoagulant effect and action mechanism of sulphated flavonoids from Flaveria bidentis

Quercetin 3-acetyl-7,3',4'-trisulphate (ATS) and quercetin 3,7,3',4'-tetrasulphate (QTS) obtained from Flaveria bidentis (Asteraceae) were investigated in vitro for anticoagulant activity. Three different concentrations of each flavonoid were assayed at different incubation times, showing at 1 mM significant prolongation on the activated partial thromboplastin time (APTT), less on the prothrombin time (PT), and no effect on the thrombin time (TT). In order to define the action mechanism of the anticoagulant activity, all coagulation factors were evaluated and no important activity decrease was observed, indicating that another mechanism is involved. Thus, thrombin inhibition mediated by antithrombin III (ATIII) and heparin cofactor II (HCII) activation was investigated in comparison to the physiological activators, heparin and dermatan sulphate (DS), respectively. As a conclusion, no activation on ATIII for neither flavonoids was observed. On the contrary, QTS much more than ATS produced an activation on HCII comparable to the one of DS, indicating that these flavonoids act as agonists of this inhibitor. A plausible explanation of the effects of both flavonoids could be due to the different degree of sulphation of these molecules. According to the results obtained, and taking in account the high solubility of these natural products in aqueous media and the nontoxic nature of this family of compounds, further investigation on the antithrombotic effects of these flavonoids are merited.     

Identification of the key amino acids of gliai cell line-derived neurotrophic factor family receptor alpha 1 involved in its biological function

Glial cell line-derived neurotrophic factor （GDNF） plays a critical role in neurodevelopment and survival of midbrain dopaminergic and spinal motor neurons in vitro and in vivo. The biological actions of GDNF are mediated by a two-receptor complex consisting of a glycosylphosphatidylinositol-linked cell surface molecule, the GDNF family receptor alpha 1 （GFR alpha 1）, and receptor protein tyrosine kinase Ret. Although structural analysis of GDNF has been extensively examined, less is known about the structural basis of GFR alpha 1 function. In this study, based on evolutionary trace method and relative solvent accessibility prediction of residues, a set of trace residues that are solvent-accessible was selected for site-directed mutagenesis. A series of GFR alpha 1 mutations was made, and PC12 cell lines stably expressing different GFR alpha 1 mutants were generated. According to the survival and differentiation responses of these stable PC12 cells upon GDNF stimulation and the GDNF- GFR alpha 1-Ret interaction assay, residues 152NN153, Arg259, and 316SNS318 in the GFR alpha 1 central region were found to be critical for GFR alpha 1 binding to GDNF and eliciting downstream signal transduction. The single mutation R259A in the GFR alpha 1 molecule simultaneously lost its binding ability to GDNF and Ret. However N152A/N153A or S316A/N317A/ S318A mutation in the GFR alpha 1 molecule still retained the ability to bind with Ret. These findings suggest that distinct structural elements in GFR alpha 1 may be involved in binding to GDNF and Ret.