Data driven analysis of functional brain networks in fMRI for schizophrenia investigation

The purpose of this article is to present a methodology to identify the sources of activity in brain networks from functional magnetic resonance imaging (fMRI) data using the multiset canonical correlation analysis algorithm. The aim is to lay the foundations for a screening marker to be used as indicator of mental diseases. Group analysis blind source separation methods have proved reliable to extract the latent sources underlying the brain activities but currently there is no recognized biomarker for mental disorders. Recent studies have identified alterations in the so called default mode network (DMN) that are common to several neuropsychiatric disorders, including schizophrenia. In particular, here we account for the hypothesis that the alterations in the DMN activity can be effectively highlighted by analyzing the transient states between two different tasks. A set of fMRI data acquired from 18 subjects performing working memory tasks is investigated for such purpose. Subjects are patients affected by schizophrenia for one half and healthy control subjects for the other. Under these conditions, the proposed methodology provides high discrimination performances in terms of classification error, thereby providing promising results for a preliminary tool able to monitor the disease state or to perform a prescreening for patients at risk for schizophrenia. © 2014 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 24, 239–248, 2014     

Doppler centroid estimation for ScanSAR data

We introduce a novel accurate technique to estimate the Doppler centroid (DC) in ScanSAR missions. The technique starts from the ambiguous DC measures in the subswaths and uses a method alternative to standard unwrapping to undo the jumps in estimates induced by modulo pulse repetition frequency (PRF) measures. The proposed alternative is less error prone than the usual unwrapping techniques. Doppler Ambiguity is then solved by implementing a maximum-likelihood estimate that exploits the different PRFs used in different subswaths. An azimuth pointing of the antenna that does not change with subswaths, or that changes in a known way, is assumed. However, if the PRF diversity is strong enough, unknown small changes in azimuth pointing are tolerated and accurately estimated. This estimator is much simpler and more efficient, than those in the literature. Results achieved with both RADARSAT 1 and ENVISAT ScanSAR data are reported.     

Comparison of three different atrial septal defect occlusion devices

Three different devices were used to close secundum-type atrial septal defects in 28 patients. The "Amplatzer" is associated with an easier and shorter procedure than are the "Sideris Buttoned Device" and the Microvena "Angel Wings" devices.     

Platelet sialic acid and platelet survival after aggregation by ADP

Some investigators have reported recently that platelet surface sialic acid is decreased during ADP-induced aggregation, whereas others have reported an increase. Since removal of sialic acid from the platelet surface shortens platelet survival, we have determined the survival of platelets that have been aggregatad by ADP. We have also measured the amount of sialic acid in the suspending fluid of platelets after ADP-induced aggregation. ADP-induced aggregation did not cause the loss of sialic acid from rabbit platelets (which do not undergo a release reaction in response to ADP) nor from washed human platelets in a medium containing physiologic concentrations of calcium in which granule contents are not released. In a medium without added calcium, ADP caused the release of 14C-serotonin (42.5% +/- 3%) from human platelets, but less than 4% of the sialic-acid-containing material was released. It seems likely that little of the releasable sialic acid of platelets is in the dense granules or the alpha-granules. Thrombin (5 U/ml) released 90.0% +/- 3.4% of the serotonin from human platelets but only 20.6% +/- 7.4% of the total sialic-acid-containing material. Neuraminidase removed 42.3% of the total sialic acid, presumably from the platelet surface. Rabbit platelets that had been aggregated by ADP and deaggregated survived normally when returned to the circulation. This observation also provides evidence that they had not lost membrane sialic acid during aggregation and deaggregation.     

Clinical outcomes and molecular genotyping of Staphylococcus aureus isolated from milk samples of dairy primiparous Mediterranean buffaloes (Bubalus bubalis)

Staphylococcus aureus is one of the most important pathogens causing mastitis in dairy cows and in Mediterranean buffaloes. Genotype B (GTB) is contagious in dairy cows and may occur in up to 87% of cows of a dairy herd. It was the aim of this study to evaluate genotypes present, clinical outcomes, and prevalence of Staph. aureus in milk samples of primiparous Mediterranean dairy buffaloes. Two hundred composite milk samples originating from 40 primiparous buffaloes were collected from May to June 2012, at d 10, 30, 60, 90, and 150 d in milk (DIM) to perform somatic cell counts and bacteriological cultures. Daily milk yields were recorded. Before parturition until 40 to 50 DIM, all primiparous animals were housed separated from the pluriparous animals. Milking was performed in the same milking parlor, but the primiparous animals were milked first. After 50 DIM, the primiparous were mixed with the pluriparous animals, including the milking procedure. Individual quarter samples were collected from each animal, and aliquots of 1 mL were mixed and used for molecular identification and genotyping of Staph. aureus. The identification of Staph. aureus was performed verifying the presence of nuc gene by nuc gene PCR. All the nuc-positive isolates were subjected to genotype analysis by means of PCR amplification of the 16S-23S rRNA intergenic spacer region and analyzed by a miniaturized electrophoresis system. Of all 200 composite samples, 41 (20.5%) were positive for Staph. aureus, and no genotype other than GTB was identified. The prevalence of samples positive for Staph. aureus was 0% at 10 DIM and increased to a maximum of 22/40 (55%) at 90 DIM. During the period of interest, 14 buffaloes tested positive for Staph. aureus once, 6 were positive twice, and 5 were positive 3 times, whereas 15 animals were negative at every sampling. At 90 and 150 DIM, 7 (17.5%) and 3 buffaloes (7.5%), respectively, showed clinical mastitis (CM), and only 1 (2.5%) showed CM at both samplings. At 60, 90, and 150 DIM, 1 buffalo was found with subclinical mastitis at each sampling. At 30, 60, 90, and 150 DIM, 2.5 (1/40), 22.5 (9/40), 35 (14/40), and 10% (4/40) were considered affected by intramammary infection, respectively. Buffaloes with CM caused by Staph. aureus had statistically significantly higher mean somatic cell count values (6.06 ± 0.29, Log₁₀ cells/mL ± standard deviation) and statistically significantly lower mean daily milk yields (7.15 ± 1.49, liters/animal per day) than healthy animals (4.69 ± 0.23 and 13.87 ± 2.64, respectively), buffaloes with IMI (4.82 ± 0.23 and 11.16 ± 1.80, respectively), or with subclinical mastitis (5.47 ± 0.10 and 10.33 ± 0.68, respectively). Based on our knowledge, this is the first time that Staph. aureus GTB has been identified in milk samples of dairy Mediterranean buffaloes.     

Short communication: Effects of systemic treatment with penethamate hydriodide on udder health and milk yields in dry primiparous Mediterranean buffaloes (Bubalus bubalis)

The effects of penethamate hydriodide (Mamyzin, Boehringer Ingelheim, Ingelheim, Germany) on udder health and milk yields were evaluated in primiparous Mediterranean buffaloes (Bubalus bubalis). An intramuscular administration of 10 million international units was performed in 20 buffaloes at 7 d precalving (treatment group; TG), and 20 animals were enrolled as the control group (CG). Evening milk samplings were performed at 10, 30, and 60 d in milk (DIM). Somatic cell count (SCC) values were evaluated on composite milk samples, whereas bacteriological culture and California Mastitis Test were performed on quarter milk. Daily milk yields were recorded after all milkings. After 60 DIM, composite milk samples from each animal were collected for monthly SCC and bacteriological culture until drying off. Statistically significant differences were found between the prevalence of mastitic quarters in the 2 groups at 10 and 30 DIM, and between the incidence of mastitic animals during the examined period (TG: 4/20, 20% vs. CG: 10/20, 50%). Even though lower and higher values of SCC and milk yields were found in TG during each sampling, statistically significant differences were only found at 30 (SCC) and 60 DIM (milk yields). In our study, the antibiotic administration precalving showed good bactericidal activity against the most common udder-specific pathogens that cause mastitis in primiparous Mediterranean buffaloes, and greater efficacy was observed at 10 and 30 DIM compared with 60 DIM. Given the significant decrease in SCC and increase in yields achieved, use of this antibiotic could be economically beneficial in buffalo breeding.     

Molecular imaging and therapy directed at the neovasculature in pathologies

We have discussed the impact of molecular imaging on clinical and preclinical medicine. We have presented the potential problems of delivering the effective therapeutic dose and the properties that can help contribute to the drug efficacy. The rationale for the design of new antiangiogenic agents that can be used for imaging and therapy was presented. Finally, results from imaging and targeted nanoparticle based therapies were presented. In vivo imaging of angiogenic tumors using anti-alpha(v)beta3 -targeted polymerized vesicles composed of the murine antibody LM609 attached to NPs labeled with the MR contrast agent gadolinium in the V2 carcinoma model in rabbits. MRI studies using this targeted contrast agent revealed large areas of alpha(v)beta3 integrin expression in tumor-associated vasculature that conventional MRIs failed to show. Other investigators have used microemulsions conjugated to an antibody targeted against alpha(v)beta as imaging agents. These materials also show contrast enhancement of tumor vasculature undergoing angiogenesis. Other markers, such as the PECAM-1 (CD-31), VCAM-1 (CD54) and VEGF receptor (flk-1), have been shown to be upregulated on tumor endothelium and associated with angiogenesis but have not been used in imaging studies. Furthermore, by modification of the NPs, we were able to use this imaging agent as an antiangiogenic gene delivery system. The results from these studies are very promising and are being further pursued.