Biomphalaria glabrata amoebocytes: Effect of Schistosoma mansoni infection on in vitro phagocytosis

The rate of phagocytosis by amoebocytes obtained from hemolymph of the pulmonate Biomphalaria glabrata infected with the trematode Schistosoma mansoni for 24 hr and 2, 4, and 6 weeks has been determined using the monolayer assay system. Amoebocyte preparations from snails infected for 4 and 6 weeks showed a gradual decrease in the phagocytic rates compared to those from uninfected controls. Snails harboring the parasite for 4 and 6 weeks also showed a significant increase in the number of amoebocytes in the hemolymph. No significant changes were detected in the rate of phagocytosis or number of amoebocytes in snails infected for 2 weeks or less. Alterations in the morphology and behavior of amoebocytes from infected snails were also noted.     

Effect of bis(acetato)tetrakis(imidazole) copper(II) in delaying the onset and reducing the mortality rate of strychnine- and thiosemicarbazide—Induced convulsions

The anticonvulsant activity of bis(acetato)tetrakis(imidazole) copper(II), Cu(OAc)₂(Im)₄, was studied in normal mice using chemical convulsions induced by strychnine, thiosemicarbazide, picrotoxin, and pentelenetetrazol. Intraperitoneal administration of Cu(OAc) ₂(Im)₄, 50 mg/kg body mass, has delayed the onset of strychnine (3 mg/kg)-induced convulsion by 204% (p≤0.005) and thiosemicarbazide (20 mg/kg)-induced convulsant by 61% (p≤0.005). The changes in the onset of picrotoxin-(6 mg/kg) and pentelenetetrazol (50 mg/kg)-induced convulsions were not significant. The same dosage of the copper compound was effective in delaying the lethal time and reducing the mortality rate of treated animals. The anticonvulsant activity of Cu(OAc) ₂(Im)₄ complex against strychnine was not related to its constituents because the inorganic form of copper such as copper chloride, copper acetate, and the parent imidazole has no anticonvulsant activity. Other copper(II) complexes like copper(II)aspirinate and bis(acetato)bis(2-methyl imidazole) copper(II) were less effective.     

Changes inγ-aminobutyric acid during different stages of picrotoxin-induced seizure,and the effect of pretreatment withγ-acetylenic GABA and phenobarbital

Changes in GABA content of various brain areas during different stages of picrotoxin-induced seizures and following pretreatment with the anti-convulsants phenobarbital andγ-acetylenic GABA were studied. Picrotoxin (6mg/kg) produced clonic/tonic convulsions associated with a 34% reduction in GABA content of the sensory motor cortex. A reduction of 24% was observed 1 min before the onset of seizure and the reduction in GABA content was reversible 20 min after the convulsion. No significant changes were observed in the cerebellum or spinal cord/medulla oblongata. Pretreatment with phenobarbital (100mg/kg) delayed the onset of convulsion and decreased the mortality rate without causing any change in GABA content at the pre-convulsive, convulsive or post-convulsive stages.γ-Acetylenic GABA (100mg/kg) has elevated GABA levels in different areas of the brain by 2–3-fold after 60 min treatment. This increase was reduced by 44% during the onset of picrotoxin-induced seizures. Picrotoxin convulsion can occur in the presence of normal, reduced or even elevated brain GABA content. The only consistent factor is a one-third reduction in GABA content before the onset of seizure.     

Genomic divergence of zebu and taurine cattle identified through high-density SNP genotyping

Background

Natural selection has molded evolution across all taxa. At an arguable date of around 330,000 years ago there were already at least two different types of cattle that became ancestors of nearly all modern cattle, the Bos taurus taurus more adapted to temperate climates and the tropically adapted Bos taurus indicus. After domestication, human selection exponentially intensified these differences. To better understand the genetic differences between these subspecies and detect genomic regions potentially under divergent selection, animals from the International Bovine HapMap Experiment were genotyped for over 770,000 SNP across the genome and compared using smoothed F_ST. The taurine sample was represented by ten breeds and the contrasting zebu cohort by three breeds.

Results

Each cattle group evidenced similar numbers of polymorphic markers well distributed across the genome. Principal components analyses and unsupervised clustering confirmed the well-characterized main division of domestic cattle. The top 1% smoothed F_ST, potentially associated to positive selection, contained 48 genomic regions across 17 chromosomes. Nearly half of the top F_ST signals (n = 22) were previously detected using a lower density SNP assay. Amongst the strongest signals were the BTA7:~50 Mb and BTA14:~25 Mb; both regions harboring candidate genes and different patterns of linkage disequilibrium that potentially represent intrinsic differences between cattle types. The bottom 1% of the smoothed F_ST values, potentially associated to balancing selection, included 24 regions across 13 chromosomes. These regions often overlap with copy number variants, including the highly variable region at BTA23:~24 Mb that harbors a large number of MHC genes. Under these regions, 318 unique Ensembl genes are annotated with a significant overrepresentation of immune related pathways.

Conclusions

Genomic regions that are potentially linked to purifying or balancing selection processes in domestic cattle were identified. These regions are of particular interest to understand the natural and human selective pressures to which these subspecies were exposed to and how the genetic background of these populations evolved in response to environmental challenges and human manipulation.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-14-876) contains supplementary material, which is available to authorized users.     

Assessing signatures of selection through variation in linkage disequilibrium between taurine and indicine cattle

Background

Signatures of selection are regions in the genome that have been preferentially increased in frequency and fixed in a population because of their functional importance in specific processes. These regions can be detected because of their lower genetic variability and specific regional linkage disequilibrium (LD) patterns.

Methods

By comparing the differences in regional LD variation between dairy and beef cattle types, and between indicine and taurine subspecies, we aim at finding signatures of selection for production and adaptation in cattle breeds. The VarLD method was applied to compare the LD variation in the autosomal genome between breeds, including Angus and Brown Swiss, representing taurine breeds, and Nelore and Gir, representing indicine breeds. Genomic regions containing the top 0.01 and 0.1 percentile of signals were characterized using the UMD3.1 Bos taurus genome assembly to identify genes in those regions and compared with previously reported selection signatures and regions with copy number variation.

Results

For all comparisons, the top 0.01 and 0.1 percentile included 26 and 165 signals and 17 and 125 genes, respectively, including TECRL, BT.23182 or FPPS, CAST, MYOM1, UVRAG and DNAJA1.

Conclusions

The VarLD method is a powerful tool to identify differences in linkage disequilibrium between cattle populations and putative signatures of selection with potential adaptive and productive importance.     

The occurrence of larval Digenea in some snails in Kuwait Bay

Between February and March 1986, 18 species of snails were collected from different habitats in Kuwait Bay; 2.9% were infected. A total of 16 species of cercariae were recovered representing the following morphological types: brevifurcate-apharyngeate (1), cotylomicrocercous (2), furcocystocercous (2), gymnocephalous (1), longifurcate-pharyngeate (1), megalurous (3), oculate trichocercous (1), parapleurolophocercous (1), and xiphidiocercaria (4). Of the mature cercarial infections, 19.5% were furcocystocercous cercariae infecting Clypeomorus bifasciatus, followed by xiphidiocercaria (10.1%) in 4 host species. Snails harboring immature infections were encountered 142 times, mainly in the limpet Siphonaria rosea, and accounted for 52.8% of all infections. Metacercarial infection was found only in Planaxis sulcatus (1.11%). The larger variety of cerariae were recovered from the mud snail Cerithidea cingulata which contributed 6 of the species encountered. Snails from muddy and sandy habitats had higher infection rates and diversity of cercarial types than those from rocky habitats. This is possibly due to differences in the abundance of birds and fish definitive hosts in the two habitats.     

Impact of temperature on Na2Sr(PO4)F:Eu3+ phosphor

In this article, we report the synthesis of Na₂Sr_1‐x(PO₄)F:Eu_x phosphor via a combustion method. The influence of different annealing temperatures on the photoluminescence properties was investigated. The phosphor was excited at both 254 and 393 nm. Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphors emit strong orange and red color at 593 and 612 nm, respectively, under both excitation wavelengths. Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphors annealed at 1050°C showed stronger emission intensity compared with 600, 900 and 1200°C. Moreover, Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphor was found to be more intense when compared with commercial Y₂O₃:Eu³⁺ phosphor. Copyright © 2013 John Wiley & Sons, Ltd.     

Identification of plasma protein biomarkers associated with idiopathic pulmonary arterial hypertension

We have employed SELDI-TOF MS to screen for differentially expressed proteins in plasma samples from 27 patients with idiopathic pulmonary arterial hypertension (IPAH) and 26 healthy controls. One ion (m/z approximately 8600) that was found to be elevated in IPAH was validated by SELDI-TOF MS analysis of a second and separate set of plasma samples comprising 30 IPAH patients and 19 controls. The m/z 8600 was purified from plasma by sequential ion exchange and reverse-phase chromatographies and SDS-PAGE. It was identified, following trypsin digestion, by MS peptide analysis as the complement component, complement 4a (C4a) des Arg. Plasma levels of C4a des Arg measured by ELISA confirmed that the levels were significantly higher (p < 0.0001) in IPAH patients (2.12 +/- 0.27 microg/mL) compared with normal controls (0.53 +/- 0.05 microg/mL). A cut-off level of 0.6 microg/mL correctly classified 92% of IPAH patients and 80% of controls. Further studies will be needed to determine its performance as a diagnostic biomarker, whether used alone or in combination with other biomarkers. Nevertheless, this study demonstrates that putative biomarkers characteristic of IPAH can be identified using a conjoint SELDI-TOF MS - proteomics approach.     

Elevated concentration of glycogen in cobalt induced epileptogenic focus

Changes in the concentration of glycogen in various areas of the brain of epileptic rats were investigated. Epilepsy was induced by implantation of cobalt discs on the right sensory motor cortex and epileptic animals have shown clear tonic-clonic jerks of the contra-lateral fore and hind limbs. It was found that glycogen concentration was increased by 29% in the epileptogenic sensory motor cortex as compared to the same area in the contra-lateral hemisphere. Glycogen concentration in other areas within the same hemisphere remained unaffected. Implantation of nickel or copper on the same sensory motor cortex, which did not cause the typical limb jerks of epilepsy, had no effect on glycogen concentration in the same treated areas. Assay of relevant metabolites in the epileptic cortex showed an increase in the concentration of pyruvate and glucose-6-phosphate, by 218% and 112% respectively. The results suggest that the increased glycogen concentration in epileptogenic focus results from increased uptake of glucose due to neuronal hyperexcitability.     

Symmetric cyanine dyes for detecting nucleic acids

A novel approach to the design of sensitive fluorescent probes for nucleic acids detection is proposed. Suitable modifications of tri- and pentamethine cyanine dyes in the polymethine chain and/or in the heterocyclic residues can result in a significant decrease in unbound dye fluorescence intensity and an increase in dye emission intensity in the presence of DNA compared to the unsubstituted dye. The sharp enhancement in the fluorescence intensity upon dye interaction with double-stranded DNA permits the application of the modified tri- and pentamethine dyes as fluorescent probes in double-stranded DNA detection in homogeneous assays.