Mapping corpus callosum deficits in autism: an index of aberrant cortical connectivity.

BACKGROUND: Volumetric studies have reported reductions in the size of the corpus callosum (CC) in autism, but the callosal regions contributing to this deficit have differed among studies. In this study, a computational method was used to detect and map the spatial pattern of CC abnormalities in male patients with autism. METHODS: Twenty-four boys with autism (aged 10.0 +/- 3.3 years) and 26 control boys (aged 11.0 +/- 2.5 years) underwent a magnetic resonance imaging (MRI) scan at 3 Tesla. Total and regional areas of the CC were determined using traditional morphometric methods. Three-dimensional (3D) surface models of the CC were also created from the MRI scans. Statistical maps were created to visualize morphologic variability of the CC and to localize regions of callosal thinning in autism. RESULTS: Traditional morphometric methods detected a significant reduction in the total callosal area and in the anterior third of the CC in patients with autism; however, 3D maps revealed significant reductions in both the splenium and genu of the CC in patients. CONCLUSIONS: Statistical maps of the CC revealed callosal deficits in autism with greater precision than traditional morphometric methods. These abnormalities suggest aberrant connections between cortical regions, which is consistent with the hypothesis of abnormal cortical connectivity in autism.     

Eco-friendly microbial route to synthesize cobalt nanoparticles using Bacillus thuringiensis against malaria and dengue vectors

The developments of resistance and persistence to chemical insecticides and concerns about the non-target effects have prompted the development of eco-friendly mosquito control agents. The aim of this study was to investigate the larvicidal activities of synthesized cobalt nanoparticles (Co NPs) using bio control agent, Bacillus thuringiensis against malaria vector, Anopheles subpictus and dengue vector, Aedes aegypti (Diptera: Culicidae). The synthesized Co NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy, and Transmission electron microscopy (TEM). XRD analysis showed three distinct diffraction peaks at 27.03°, 31.00°, and 45.58° indexed to the planes 102, 122, and 024, respectively on the face-centered cubic cobalt acetate with an average size of 85.3 nm. FTIR spectra implicated role of the peak at 3,436 cm^?1 for O–H hydroxyl group, 2924 cm^?1 for methylene C–H stretch in the formation of Co NPs. FESEM analysis showed the topological and morphological appearance of NPs which were found to be spherical and oval in shape. TEM analysis showed polydispersed and clustered NPs with an average size of 84.81 nm. The maximum larvicidal mortality was observed in the cobalt acetate solution, B. thuringiensis formulation, and synthesized Co NPs against fourth instar larvae of A. subpictus and A. aegypti with LC₅₀ values of 29.16, 8.12, 3.59 mg/L; 34.61, 6.94, and 2.87 mg/L; r ² values of 0.986, 0.933, 0.942; 0.962, 0.957, and 0.922, respectively.     

Green synthesis of titanium dioxide nanoparticles using Psidium guajava extract and its antibacterial and antioxidant properties

Objective:To determine the efficacies of antibacterial and antioxidant activities of aqueous leaf extract of Psidium guajava mediated biosynthesis of titanium dioxide nanoparticles(TiO_2,NPs).Methods:Synthesized TiO_2 NPs were tested by disc diffusion method against against human pathogenic bacteria.The total antioxidant activity and phenolic content(Folin—Ciocalteau method) of synthesized TiO_2 NTs and aqueous plant extract were determined.The scavenging radicals were estimated hv DPPH method.The synthesized TiO_2 NPs were characterized by XRD,FTIR.FESEM and EDX,Results:FTIR spectra of synthesized TiO_2 NPs exhibited prominent peaks at 3410 cm~(-1)(alkynes),1 578 cm~(-1).1 451 cm~(-1)(alkanes),and 1 123 cm~(-1)(C-O absorption).The morphological characterization of synthesized TiO_2 NPs was analysed by FESEM which showed spherical shape and clusters with an average size of 32.58 nm.The maximum zone of inhibition was observed in the synthesized TiO_2 NPs(20 μg/mL) against Staphylococcus aureus(25 mm) and Escherichia coli(23 mm).The synthesized TiO_2 NPs showed more antibacterial activity than the standard antibiotic disk,tetracycline which drastically reduces the chances for the development of antibiotics resistance of bacterial species.The plant aqueous extract and synthesized TiO_2NPs were found to possess maximum antioxidant activity when compared with ascorbic acid.The content of phenolic compounds(mg/g) in Leaf aqueous extract and synthesized TiO_2 NPs were found to be 85.4 and 18.3 mgTA/g,respectively.Conclusions:Green synthesized TiO_2 NPs provides a promising approach can satisfy the requirement of large-scale industrial production hearing the advantage of low—cost,eco—friendly and reproducible.     

Influence of lattice strain on Fe3O4@carbon catalyst for the destruction of organic dye in polluted water using a combined adsorption and Fenton process

In this study, 8, 25 and 50 wt% Fe₃O₄@activated carbon (AC) catalysts were prepared by simple coprecipitation method. The efficiency of the catalysts for the advanced Fenton''s oxidation process using methylene blue (MB) as a model substrate was tested. Both modified and unmodified activated carbon catalysts exhibited similar activity towards the Fenton''s oxidation process. Therefore, it is difficult to identify the role of the catalyst in this dye removal process. Hence, we proposed a new methodology to remove the MB by adopting the adsorption process initially, followed by the Fenton''s oxidation process. The proposed process significantly improved the methylene blue decomposition reaction over the 25 wt% Fe₃O₄@AC catalyst. However, this trend was not seen in pure activated carbon and Fe₃O₄@AC (8 and 50 wt%) catalysts due to the instability of the material in the oxidizing medium. The possible reason for the deactivation of the catalysts was evaluated from lattice strain calculations, as derived from the modified W–H models (Uniform Deformational Model (UDM), Uniform Stress Deformation Model (USDM) and Uniform Deformation Energy Density Model (UDEDM)). These results provided a quantitative relationship between the experimentally calculated lattice strain values and Fenton''s catalytic activity. Furthermore, the optimized strain value and crystalite size of Fe₃O₄ on the activated carbon matrix are responsible for the high catalytic activity.

The activity of the catalyst was directly correlated using lattice strain calculations, as derived from the W–H model.     

Effects of subthalamic nucleus lesions in a putative model of tardive dyskinesia in the rat

The effects of bilateral excitotoxic lesions of the subthalamic nucleus on vacuous chewing movements induced by chronic neuroleptic therapy were examined in the rat. Fluphenazine decanoate (25 mg/kg i.m. q 3 weeks × 24 weeks) induced vacuous chewing movements, as previously described. This response was suppressed to control levels in animals tested 1–3 weeks following bilateral infusion of quinolinic acid (100 nmol/1 μl per side) into the subthalamic nucleus. Subthalamic nucleus lesions resulted in increased locomotion and sniffing in neuroleptic-naive animals, but these responses were suppressed by concomitant neuroleptic treatment. As vacuous chewing movements induced by chronic neuroleptics are considered to be analogous to tardive dyskinesia in humans, our findings lend further support to the importance of the subthalamic nucleus in the regulation of orofacial movements and suggest that tardive dyskinesia may, in part, be related to altered activity in this structure. This, in turn, suggests that current models of basal ganglia function are inadequate to account for certain pathological states and require re-examination. © 1996 Wiley-Liss, Inc.     

Placental system A amino acid transport is reduced in pregnancies with small for gestational age (SGA) infants but not in preeclampsia with SGA infants

Preeclampsia and intrauterine growth restriction (IUGR) are both associated with abnormal remodeling of maternal spiral arteries perfusing the placental site. This would be expected to be associated with reduced fetal growth, yet only one third of infants of mothers with preeclampsia are growth restricted. Infants with IUGR have decreased concentrations of amino acids in their blood and system A amino acid transporter activity is reduced in their placentas. Since infants of preeclamptic pregnancies have increased circulating amino acids, we tested system A amino acid transport activity of placental villous fragments from pregnancies with small for gestational age (SGA) infants with and without maternal preeclampsia and from uncomplicated and preeclamptic pregnancies with normal sized infants. We confirm the reduced uptake of amino acids in SGA pregnancies without preeclampsia but report that placental amino acid uptake of SGA infants with maternal preeclampsia is not reduced and is identical to uptake by normal and preeclamptic pregnancies with normal weight infants.     

Brain magnetic resonance spectroscopy in Tourette's disorder

OBJECTIVE: Although abnormalities of neural circuits involving the cortex, striatum, and thalamus are hypothesized to underlie Tourette's disorder, the neuronal abnormalities within components of these circuits are unknown. The purpose of this study was to examine the cellular neurochemistry within these circuits in Tourette's disorder using proton magnetic resonance spectroscopy, a method that has not previously been used in neurobiological investigations of the disorder. METHOD: Proton magnetic resonance spectroscopic imaging examinations were conducted in 25 males with Tourette's disorder (age 10.9 +/- 2.0 years) and 32 male comparison subjects (age 11.5 +/- 2.7 years). Spectra from frontal cortex, caudate nucleus, putamen, and thalamus were analyzed, and N-acetylaspartate, creatine, choline, myoinositol, and glutamate + glutamine were quantified and compared between the groups. RESULTS: Patients with Tourette's disorder demonstrated a reduction in N-acetylaspartate and choline in the left putamen, along with reduced levels of creatine bilaterally in the putamen. In the frontal cortex, patients had significantly lower concentrations of N-acetylaspartate bilaterally, lower levels of creatine on the right side, and reduced myoinositol on the left side. CONCLUSIONS: The results of this study suggest compromised neuronal integrity and deficits in density of neuronal and nonneuronal cells in components of the neural circuits implicated in Tourette's disorder.     

Use of genome level-informed PCR as a new investigational approach for analysis of outbreak-associated Mycobacterium tuberculosis isolates

Mycobacterium tuberculosis strain CH, the index isolate linked to a major tuberculosis outbreak associated with high levels of transmissibility and virulence, was characterized by microarray analysis by use of a PCR product array representative of the genome of M. tuberculosis strain H37Rv. Seven potential genomic deletions were identified in CH, five of which were confirmed by PCR analysis across the predicted deletion points. The panel of five PCRs required to individually interrogate these loci was collectively referred to as the genome level-informed PCR (GLIP) assay. GLIP analysis was performed with CH, 12 other epidemiologically linked isolates, and 43 recent, non-outbreak-associated isolates derived from patients within the local area. All 13 outbreak-linked isolates showed a profile corresponding to the presence of all five deletions. These 13 isolates were also found to share common variable-number tandem repeat and mycobacterial interspersed repetitive unit profiles. None of the 43 non-outbreak-associated isolates exhibited the five-deletion profile. Although three individual deletions were present in upwards of 44% of the non-outbreak-associated isolates, no single-deletion isolates were detected. Interestingly, none of these deletions had been previously recognized, and sequence analysis of the immediate flanking regions in CH failed to identify a likely mechanism of deletion for four of the five loci. The GLIP assay also proved valuable in ongoing surveillance of the outbreak, rapidly identifying a further two outbreak-associated cases months after the initial cluster and, importantly, dismissing a further 12 epidemiologically suspect cases, which allowed the optimum deployment of public health resources.