Nucleotide sequence and expression of the ncr nickel and cobalt resistance in Hafnia alvei 5-5

The structural genes for the nickel and cobalt resistance of the conjugative plasmid pEJH 501 of Hafnia alvei 5-5, contained on a SalI-EcoRI fragment of 4.8 kb, were cloned and sequenced. The DNA sequence included five genes in the following order: ncrA, ncrB, ncrC, ncrY, and ncrX. The predicted amino acid sequences of ncrA were homologous to the amino acid sequences of nreB of Achromobacter xylosoxidans 31A. Expression of ncr with the T7 RNA polymerase-promoter system allowed Escherichia coli BL21 (DE3) to overexpress NcrA, NcrB, and NcrC but not NcrY, and NcrX. The apparent molecular masses of NcrA, NcrB, and NcrC were 30, 33, and 17 kDa, respectively. Primer-extension analysis showed that ncr mRNA started at nucleotide position 23 upstream from ncrA. The promoter region of the ncr operon possessed a strong, putative –35 element of σ32-type promoter sequence, and transcriptional 'lacZ fusion studies indicated that the –35 element influenced σ32-specific transcription. [Int Microbiol 2004; 7(1):27–34

Conjugative plasmid mediated inducible nickel resistance in Hafnia alvei 5-5

Hafnia alvei 5-5, isolated from a soil-litter mixture underneath the canopy of the nickel-hyperaccumulating tree Sebertia acuminata (Sapotaceae) in New Caledonia, was found to be resistant to 30 mM Ni2+ or 2 mM Co2+. The 70-kb plasmid, pEJH 501, was transferred by conjugation to Escherichia coli, Serratia marcescens, and Klebsiella oxytoca. Transconjugant strains expressed inducible nickel resistance to between 5 and 17 mM Ni2+, and cobalt resistance to 2 mM Co2+. A 4.8-kb Sal–EcoRI fragment containing the nickel resistance determinant was subcloned, and the hybrid plasmid was found to confer a moderate level of resistance to nickel (7 mM Ni2+) even to E. coli. The expression of nickel resistance was inducible by exposure to nickel chloride at a concentration as low as 0.5 mM Ni2+. By random TnphoA´-1 insertion mutagenesis, the fragment was shown to have structural genes as well as regulatory regions for nickel resistance. Southern hybridization studies showed that the nickel-resistance determinant from pEJH501 of H. alvei 5-5 was homologous to that of pTOM9 from Alcaligenes xylosoxydans 31A

Cathelicidin suppresses lipid accumulation and hepatic steatosis by inhibition of the CD36 receptor.

Background and objectivesObesity is a global epidemic which increases the risk of the metabolic syndrome. Cathelicidin (LL-37 and mCRAMP) is an antimicrobial peptide with an unknown role in obesity. We hypothesize that cathelicidin expression correlates with obesity and modulates fat mass and hepatic steatosis.Materials and methodsMale C57BL/6 J mice were fed a high-fat diet. Streptozotocin was injected into mice to induce diabetes. Experimental groups were injected with cathelicidin and CD36 overexpressing lentiviruses. Human mesenteric fat adipocytes, mouse 3T3-L1 differentiated adipocytes and human HepG2 hepatocytes were used in the in vitro experiments. Cathelicidin levels in non-diabetic, prediabetic and type II diabetic patients were measured by enzyme-linked immunosorbent assay.ResultsLentiviral cathelicidin overexpression reduced hepatic steatosis and decreased the fat mass of high-fat diet-treated diabetic mice. Cathelicidin overexpression reduced mesenteric fat and hepatic fatty acid translocase (CD36) expression that was reversed by lentiviral CD36 overexpression. Exposure of adipocytes and hepatocytes to cathelicidin significantly inhibited CD36 expression and reduced lipid accumulation. Serum cathelicidin protein levels were significantly increased in non-diabetic and prediabetic patients with obesity, compared with non-diabetic patients with normal body mass index (BMI) values. Prediabetic patients had lower serum cathelicidin protein levels than non-diabetic subjects.ConclusionsCathelicidin inhibits the CD36 fat receptor and lipid accumulation in adipocytes and hepatocytes, leading to a reduction of fat mass and hepatic steatosis in vivo. Circulating cathelicidin levels are associated with increased BMI. Our results demonstrate that cathelicidin modulates the development of obesity

Clinical Presentation and Management of Jugular Foramen Paraganglioma

ObjectivesJugular foramen paraganglioma is a locally invasive, benign tumor, which grow slowly and causes various symptoms such as pulsatile tinnitus and low cranial nerve palsy. Complete surgical resection is regarded as the ideal management of these tumors. The goal of this study is to identify the clinical characteristics and most effective surgical approach for jugular foramen paraganglioma.MethodsRetrospective analysis of 9 jugular foramen paraganglioma patients who underwent surgical resection between 1986 and 2005 was performed. Clinical records were reviewed for analysis of initial clinical symptoms and signs, audiological examinations, neurological deficits, radiological features, surgical approaches, extent of resection, treatment outcomes and complications.ResultsMost common initial symptom was hoarseness, followed by pulsatile tinnitus. Seven out of 9 patients had at least one low cranial nerve palsy. Seven patients were classified as Fisch Type C tumor and remaining 2 as Fisch Type D tumor on radiologic examination. Total of 11 operations took place in 9 patients. Total resection was achieved in 6 cases, when partial resection was done in 3 cases. Two patients with partial resection received gamma knife radiosurgery (GKS), when remaining 1 case received both GKS and two times of revision operation. No mortality was encountered and there were few postoperative complications.ConclusionNeurologic examination of low cranial nerve palsy is crucial since most patients had at least one low cranial nerve palsy. All tumors were detected in advanced stage due to slow growing nature and lack of symptom. Angiography with embolization is crucial for successful tumor removal without massive bleeding. Infratemporal fossa approach can be considered as a safe, satisfactory approach for removal of jugular foramen paragangliomas. In tumors with intracranial extension, combined approach is recommended in that it provides better surgical view and can maintain the compliance of the patients

Clinical Presentation and Management of Jugular Foramen Paraganglioma

ObjectivesJugular foramen paraganglioma is a locally invasive, benign tumor, which grow slowly and causes various symptoms such as pulsatile tinnitus and low cranial nerve palsy. Complete surgical resection is regarded as the ideal management of these tumors. The goal of this study is to identify the clinical characteristics and most effective surgical approach for jugular foramen paraganglioma.MethodsRetrospective analysis of 9 jugular foramen paraganglioma patients who underwent surgical resection between 1986 and 2005 was performed. Clinical records were reviewed for analysis of initial clinical symptoms and signs, audiological examinations, neurological deficits, radiological features, surgical approaches, extent of resection, treatment outcomes and complications.ResultsMost common initial symptom was hoarseness, followed by pulsatile tinnitus. Seven out of 9 patients had at least one low cranial nerve palsy. Seven patients were classified as Fisch Type C tumor and remaining 2 as Fisch Type D tumor on radiologic examination. Total of 11 operations took place in 9 patients. Total resection was achieved in 6 cases, when partial resection was done in 3 cases. Two patients with partial resection received gamma knife radiosurgery (GKS), when remaining 1 case received both GKS and two times of revision operation. No mortality was encountered and there were few postoperative complications.ConclusionNeurologic examination of low cranial nerve palsy is crucial since most patients had at least one low cranial nerve palsy. All tumors were detected in advanced stage due to slow growing nature and lack of symptom. Angiography with embolization is crucial for successful tumor removal without massive bleeding. Infratemporal fossa approach can be considered as a safe, satisfactory approach for removal of jugular foramen paragangliomas. In tumors with intracranial extension, combined approach is recommended in that it provides better surgical view and can maintain the compliance of the patients

Molecular Cloning of Plasmodium vivax Calcium-Dependent Protein Kinase 4

A family of calcium-dependent protein kinases (CDPKs) is a unique enzyme which plays crucial roles in intracellular calcium signaling in plants, algae, and protozoa. CDPKs of malaria parasites are known to be key regulators for stage-specific cellular responses to calcium, a widespread secondary messenger that controls the progression of the parasite. In our study, we identified a gene encoding Plasmodium vivax CDPK4 (PvCDPK4) and characterized its molecular property and cellular localization. PvCDPK4 was a typical CDPK which had well-conserved N-terminal kinase domain and C-terminal calmodulin-like structure with 4 EF hand motifs for calcium-binding. The recombinant protein of EF hand domain of PvCDPK4 was expressed in E. coli and a 34 kDa product was obtained. Immunofluorescence assay by confocal laser microscopy revealed that the protein was expressed at the mature schizont of P. vivax. The expression of PvCDPK4-EF in schizont suggests that it may participate in the proliferation or egress process in the life cycle of this parasite

Ptch2/Gas1 and Ptch1/Boc differentially regulate Hedgehog signalling in murine primordial germ cell migration.

Gas1 and Boc/Cdon act as co-receptors in the vertebrate Hedgehog signalling pathway, but the nature of their interaction with the primary Ptch1/2 receptors remains unclear. Here we demonstrate, using primordial germ cell migration in mouse as a developmental model, that specific hetero-complexes of Ptch2/Gas1 and Ptch1/Boc mediate the process of Smo de-repression with different kinetics, through distinct modes of Hedgehog ligand reception. Moreover, Ptch2-mediated Hedgehog signalling induces the phosphorylation of Creb and Src proteins in parallel to Gli induction, identifying a previously unknown Ptch2-specific signal pathway. We propose that although Ptch1 and Ptch2 functionally overlap in the sequestration of Smo, the spatiotemporal expression of Boc and Gas1 may determine the outcome of Hedgehog signalling through compartmentalisation and modulation of Smo-downstream signalling. Our study identifies the existence of a divergent Hedgehog signal pathway mediated by Ptch2 and provides a mechanism for differential interpretation of Hedgehog signalling in the germ cell niche

Paraconsistent Reasoning for OWL 2

A four-valued description logic has been proposed to reason with description logic based inconsistent knowledge bases. This approach has a distinct advantage that it can be implemented by invoking classical reasoners to keep the same complexity as under the classical semantics. However, this approach has so far only been studied for the basid description logic ALC. In this paper, we further study how to extend the four-valued semantics to the more expressive description logic SROIQ which underlies the forthcoming revision of the Web Ontology Language, OWL 2, and also investigate how it fares when adapated to tractable description logics including EL++, DL-Lite, and Horn-DLs. We define the four-valued semantics along the same lines as for ALC and show that we can retain most of the desired properties

miR-132/212 knockout mice reveal roles for these miRNAs in regulating cortical synaptic transmission and plasticity

miR-132 and miR-212 are two closely related miRNAs encoded in the same intron of a small non-coding gene, which have been suggested to play roles in both immune and neuronal function. We describe here the generation and initial characterisation of a miR-132/212 double knockout mouse. These mice were viable and fertile with no overt adverse phenotype. Analysis of innate immune responses, including TLR-induced cytokine production and IFNβ induction in response to viral infection of primary fibroblasts did not reveal any phenotype in the knockouts. In contrast, the loss of miR-132 and miR-212, while not overtly affecting neuronal morphology, did affect synaptic function. In both hippocampal and neocortical slices miR-132/212 knockout reduced basal synaptic transmission, without affecting paired-pulse facilitation. Hippocampal long-term potentiation (LTP) induced by tetanic stimulation was not affected by miR-132/212 deletion, whilst theta burst LTP was enhanced. In contrast, neocortical theta burst-induced LTP was inhibited by loss of miR-132/212. Together these results indicate that miR-132 and/or miR-212 play a significant role in synaptic function, possibly by regulating the number of postsynaptic AMPA receptors under basal conditions and during activity-dependent synaptic plasticity