Duplex real-time PCR assay for the simultaneous detection of Caliciopsis pinea and Fusarium circinatum in pine samples

Applied Microbiology and Biotechnology - Fusarium circinatum and Caliciopsis pinea are the causal agents of Pitch canker and Caliciopsis canker, respectively. These diseases affect pines and other...     

Structural and Functional Insights into Bacillus subtilis Sigma Factor Inhibitor,CsfB

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Che‐1 is targeted by c‐Myc to sustain proliferation in pre‐B‐cell acute lymphoblastic leukemia

Despite progress in treating B‐cell precursor acute lymphoblastic leukemia (BCP‐ALL), disease recurrence remains the main cause of treatment failure. New strategies to improve therapeutic outcomes are needed, particularly in high‐risk relapsed patients. Che‐1/AATF (Che‐1) is an RNA polymerase II‐binding protein involved in proliferation and tumor survival, but its role in hematological malignancies has not been clarified. Here, we show that Che‐1 is overexpressed in pediatric BCP‐ALL during disease onset and at relapse, and that its depletion inhibits the proliferation of BCP‐ALL cells. Furthermore, we report that c‐Myc regulates Che‐1 expression by direct binding to its promoter and describe a strict correlation between Che‐1 expression and c‐Myc expression. RNA‐seq analyses upon Che‐1 or c‐Myc depletion reveal a strong overlap of the respective controlled pathways. Genomewide ChIP‐seq experiments suggest that Che‐1 acts as a downstream effector of c‐Myc. These results identify the pivotal role of Che‐1 in the control of BCP‐ALL proliferation and present the protein as a possible therapeutic target in children with relapsed BCP‐ALL.     

Hyperammonaemia in classic organic acidaemias: a review of the literature and two case histories

Background

The ‘classic’ organic acidaemias (OAs) (propionic, methylmalonic and isovaleric) typically present in neonates or infants as acute metabolic decompensation with encephalopathy. This is frequently accompanied by severe hyperammonaemia and constitutes a metabolic emergency, as increased ammonia levels and accumulating toxic metabolites are associated with life-threatening neurological complications. Repeated and frequent episodes of hyperammonaemia (alongside metabolic decompensations) can result in impaired growth and intellectual disability, the severity of which increase with longer duration of hyperammonaemia. Due to the urgency required, diagnostic evaluation and initial management of patients with suspected OAs should proceed simultaneously. Paediatricians, who do not have specialist knowledge of metabolic disorders, have the challenging task of facilitating a timely diagnosis and treatment. This article outlines how the underlying pathophysiology and biochemistry of the organic acidaemias are closely linked to their clinical presentation and management, and provides practical advice for decision-making during early, acute hyperammonaemia and metabolic decompensation in neonates and infants with organic acidaemias.

Clinical management

The acute management of hyperammonaemia in organic acidaemias requires administration of intravenous calories as glucose and lipids to promote anabolism, carnitine to promote urinary excretion of urinary organic acid esters, and correction of metabolic acidosis with the substitution of bicarbonate for chloride in intravenous fluids. It may also include the administration of ammonia scavengers such as sodium benzoate or sodium phenylbutyrate. Treatment with N-carbamyl-L-glutamate can rapidly normalise ammonia levels by stimulating the first step of the urea cycle.

Conclusions

Our understanding of optimal treatment strategies for organic acidaemias is still evolving. Timely diagnosis is essential and best achieved by the early identification of hyperammonaemia and metabolic acidosis. Correcting metabolic imbalance and hyperammonaemia are critical to prevent brain damage in affected patients.

     

Contribution of volatile organic compound fluxes to the ecosystem carbon budget of a poplar short‐rotation plantation

Biogenic volatile organic compounds (BVOCs) are major precursors of both ozone and secondary organic aerosols (SOA) in the troposphere and represent a non‐negligible portion of the carbon fixed by primary producers, but long‐term ecosystem‐scale measurements of their exchanges with the atmosphere are lacking. In this study, the fluxes of 46 ions corresponding to 36 BVOCs were continuously monitored along with the exchanges of mass (carbon dioxide and water vapor) and energy (sensible and latent heat) for an entire year in a poplar (Populus) short‐rotation crop (SRC), using the eddy covariance methodology. BVOC emissions mainly consisted of isoprene, acetic acid, and methanol. Total net BVOC emissions were 19.20 kg C ha^?1 yr^?1, which represented 0.63% of the net ecosystem exchange (NEE), resulting from ?23.59 Mg C ha^?1 yr^?1 fixed as CO₂ and 20.55 Mg C ha^?1 yr^?1 respired as CO₂ from the ecosystem. Isoprene emissions represented 0.293% of NEE, being emitted at a ratio of 1 : 1709 mol isoprene per mol of CO₂ fixed. Based on annual ecosystem‐scale measurements, this study quantified for the first time that BVOC carbon emissions were lower than previously estimated in other studies (0.5–2% of NEE) on poplar trees. Furthermore, the seasonal and diurnal emission patterns of isoprene, methanol, and other BVOCs provided a better interpretation of the relationships with ecosystem CO₂ and water vapor fluxes, with air temperature, vapor pressure deficit, and photosynthetic photon flux density.     

Cleavage of di- and tripeptides by Prevotella ruminicola

The final step in the conversion of protein to amino acids by the common Gram-negative rumen bacterium, Prevotella (formerly Bacteroides) ruminicola , is the cleavage of di- and tripeptides. Dipeptidase and tripeptidase activities were predominantly cytoplasmic, and toluene treatment increased the rate of Ala₂ and Ala₃ hydrolysis by whole cells, suggesting that transport limited the rate of hydrolysis of extracellular di- and tripeptides. The hydrolysis of Ala₂ and Ala₃ by whole cells was not affected by protonophores, ionophores or dicyclohexylcarbodiimide, but Ala₂ hydrolysis by EDTA-treated cells was inhibited by the Ca²⁺/H⁺ ionophore, tetronasin. Ala₃ hydrolysis was not affected by protonophores or ionophores in EDTA-treated cells. The dipeptidase of strain M384 was inhibited > 99% by 1,10-phenanthroline and 39% by EDTA but not other protease inhibitors, consistent with the enzyme being a metalloprotease. Tripeptidase was insensitive to protease inhibitors, except for a 33% inhibition by EDTA. Cleavage of tripeptides occurred at the bond adjacent to the N-terminal amino acid. Distinct di-, tri- and oligopeptidase peaks were obtained by anion-exchange liquid chromatography of disrupted cells. Banding patterns on native PAGE using activity staining also indicated that P. ruminicola M384 had separate single dipeptidase and tripeptidase enzymes which hydrolysed a range of peptides. The dipeptidase of strain M384 was different from other strains of P. ruminicola: strains GA33 and B₁4 had activities which ran at the same R_f; strain GA33 had another band of lower activity; strain 23 had two bands different from those of the other strains. The tripeptidases ran at the same R_f for the different strains. Dipeptidase activity of all strains was inhibited by 1,10-phenanthroline on gels. Gel permeation chromatography indicated that the M_r of the dipeptidases from strains M384 and B₁4 were 115 000 and 114 500 respectively, and 112 500 and 121 500 for the corresponding tripeptidases. Thus the metabolism of small peptides by P. ruminicola involves separate permeases and intracellular peptidases for di- and tripeptides.     

Homing Experiments in the Tree-climbing Crab Sesarma leptosoma (Decapoda,Grapsidae)

Sesarma leptosoma an East African mangrove-dwelling crab, migrates twice a day from a system of known dens among the roots to well-defined feeding areas in the branches of trees, reaching 15 m high. Field experiments were performed to test whether chemical or visual cues are involved in the orientation and homing of this species to reach their feeding areas. Manipulation of the substratum at branch junctions, in order to alter possible chemical cues, did not affect homing ability in S. leptosoma. Moreover, crabs trained to cross an asymmetrical artificial wooden fork could still follow their preferred directions after (1) the fork branches had been switched, (2) the whole fork had been rotated around the trunk, resulting in a right-left inversion, and (3) the inversion of two wide black and white screens hiding most of the canopy from view of the climbing crabs. These results suggest that S. leptosoma may not rely on reference systems such as chemical trail-following and chemical or visual cues from the substratum, but probably depend on complex visual information from the surroundings trunks and/or from the sun's position integrated with junction sequence memory.     

Strategies for the identification and purification of ligands for orphan biomolecules

Summary The isolation of related genes with evolutionary conserved motifs by the application of polymerase chain reaction-based molecular biology techniques, or from database searching strategies, has facilitated the identification of new members of protein families. Many of these protein molecules will be involved in protein-protein interactions (e.g. growth factors, receptors, adhesion molecules), since such interactions are intrinsic to virtually every cellular process. However, the precise biological function and specific binding partners of these novel proteins are frequently unknown, hence they are known as ‘orphan’ molecules. Complementary technologies are required for the identification of the specific ligands or receptors for these and other orphan proteins (e.g., antibodies raised against crude biological extracts or whole cells). We describe herein several alternative strategies for the identification, purification and characterisation of orphan peptide and protein molecules, specifically the synergistic use of micropreparative HPLC and biosensor techniques. These authors made equivalent contributions.     

Six new polymorphic microsatellite markers used for the integration of genetic and physical maps of human chromosome 7

We report the isolation and characterization of six new polymorphic dinucleotide repeat microsatellite markers (D7S1491, D7S1492, D7S1493, D7S1494, D7S1495, and D7S1496), their integration into the genetic map of human chromosome 7 by analysis of 40 CEPH (Centre d’Etude du Polymorphisme Humain) pedigrees, and their use for integration of physical and genetic maps of this chromosome. Received: 14 September 1995 / Revised: 23 December 1995     

Evaluation of P-glycoprotein expression in soft tissue sarcomas of the extremities

Soft tissue sarcomas comprise a heterogeneous group of mesenchymal tumors accounting for less than one-percent of adult neoplasms. In the last few years, the use of adjuvant chemotorapy has been proposed for the treatment of these lesions in order to obain a better systemic control, but its usefulness is still controversial. In this study, we evaluated whether P-glycoprotein, a membrane protein strictly associated with multidrug resistance, is overexpressed in soft tissue sarcomas. By using human multidrug resistant sarcoma cell lines as controls, we analyzed P-glycoprotein expression in 34 primary and in 23 relapsed soft tissue sarcomas of the extremities. Overexpression of P-glycoprotein was found in 6 out of 34 primaries (18%) and in 8 out of 23 relapses (35%). In particular, in malignant fibrous histiocytoma, the most frequent soft tissue sarcoma of adults, P-glycoprotein overexpression was found in 23% of primary untreated cases, in agreement with the reported relapse rate of this tumor after surgery and chemotherapy. These data suggest that, in soft tissue sarcomas, overexpression of P-glycoprotein may be of prognostic value and that the assessment of P-glycoprotein expression may be useful for the design of chemotherapy protocols.Abbreviations MDR multidrug-resistance - STS soft tissue sarcomas