Successful management of severe refractory acquired immune bleeding disorder: Prior to insisting surgery

AbstractINTRODUCTIONAcquired bleeding disorders are rare and may be missed before surgery. Additionally, they may be refractory to conventional treatments.PRESENTATION OF CASEA 50-year-old patient experienced prolonged post-operative bleeding when his bleeding disorder was missed prior to his undergoing inguinal herniorrhaphy. Post-operative investigations revealed severe acquired von Willebrand syndrome associated with a monoclonal gammopathy of undetermined significance. A few months later, he required umbilical herniorrhaphy, but he did not respond to attempts to raise his von Willebrand factor antigen and activity levels using conventional therapies, including desmopressin, cryoprecipitate, intravenous immunoglobulin, and Von Willebrand factor concentrate. A triple therapy combination of dexamethasone, intravenous immunoglobulin, and mycophenolate mofetil was administered, with a successful and sustained response, lasting about 2 months. The surgery was performed safely, without any complications.DISCUSSIONConventional acquired von Willebrand syndrome treatment is usually aimed at replacing von Willebrand factor or stimulating its secretion from storage in endothelial cells. In the present case, the alternative treatment was directed against both the humoral and cell-mediated immune mechanisms.CONCLUSIONThis case of acquired bleeding disorder showed that more attention must be given to a patient's coagulation profile, even if only very minor laboratory coagulation derangements are detected prior to surgery, to avoid missing such rare disorders. The described triple therapy demonstrated good effects and may be considered for inclusion in a controlled randomized study to determine its usefulness for other surgeries delayed due to severe acquired bleeding disorders. To the best of our knowledge, this triple combination treatment has not been previously used for the treatment of severe acquired bleeding disorders that are refractory to conventional therapies

Nus transcription elongation factors and RNase III modulate small ribosome subunit biogenesis in E scherichia coli

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96334/1/mmi12105.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96334/2/mmi12105-sup-0001-si.pd

Late steps of ribosome assembly in E. coli are sensitive to a severe heat stress but are assisted by the HSP70 chaperone machine†

The late stages of 30S and 50S ribosomal subunits biogenesis have been studied in a wild-type (wt) strain of Escherichia coli (MC4100) subjected to a severe heat stress (45–46°C). The 32S and 45S ribosomal particles (precursors to 50S subunits) and 21S ribosomal particles (precursors to 30S subunits) accumulate under these conditions. They are authentic precursors, not degraded or dead-end particles. The 21S particles are shown, by way of a modified 3′5′ RACE procedure, to contain 16S rRNA unprocessed, or processed at its 5′ end, and not at the 3′ end. This implies that maturation of 16S rRNA is ordered and starts at its 5′-terminus, and that the 3′-terminus is trimmed at a later step. This observation is not limited to heat stress conditions, but it also can be verified in bacteria growing at a normal temperature (30°C), supporting the idea that this is the general pathway. Assembly defects at very high temperature are partially compensated by plasmid-driven overexpression of the DnaK/DnaJ chaperones. The ribosome assembly pattern in wt bacteria under a severe heat stress is therefore reminiscent of that observed at lower temperatures in E. coli mutants lacking the chaperones DnaK or DnaJ

Rôle des protéines Chaperonnes dans la Biogénèse des Ribosomes d' Escherichia coli

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Evaluation of Piezotome-Corticision Assisted Orthodontics in Retracting Upper Canine: A Split Mouth Design (Randomized Clinical Trial)

Objectives: The aim of this randomized clinical trial is to investigate the rate of canine retraction at different time points between piezotome-corticision assisted and conventional orthodontics. Methods: Fifteen patients were submitted for upper first premolars extraction after leveling and alignment was achieved to facilitate canine retraction. They were randomly divided into test side and control side. On the test side, the canine was retracted using piezotome-corticision assisted orthodontics, while at the control side, the canine was retracted using conventional technique. Both groups were immediately loaded with a horizontal force of 150g for canine retraction. The distance between the canine bracket hook and the first molar band hook were recorded using a digital caliper. The measurements were accomplished immediately after piezosurgery at 1,2,4,8 and 12 week. Results: There was a statistically significant difference in the average amount of canine retraction between test and control groups (P<0.05). The canine on the test side was closed 6 weeks earlier than the control side. Conclusion: Piezocision is minimal invasive which accelerate the rate of canine of retraction approximately 1.5 times faster than that of conventional method

Structural characterization of B. subtilis m1A22 tRNA methyltransferase TrmK: insights into tRNA recognition

1-Methyladenosine (m1A) is a modified nucleoside found at positions 9, 14, 22 and 58 of tRNAs, which arises from the transfer of a methyl group onto the N1-atom of adenosine. The yqfN gene of Bacillus subtilis encodes the methyltransferase TrmK (BsTrmK) responsible for the formation of m1A22 in tRNA. Here, we show that BsTrmK displays a broad substrate specificity, and methylates seven out of eight tRNA isoacceptor families of B. subtilis bearing an A22. In addition to a non-Watson-Crick base-pair between the target A22 and a purine at position 13, the formation of m1A22 by BsTrmK requires a full-length tRNA with intact tRNA elbow and anticodon stem. We solved the crystal structure of BsTrmK showing an N-terminal catalytic domain harbouring the typical Rossmann-like fold of Class-I methyltransferases and a C-terminal coiled-coil domain. We used NMR chemical shift mapping to drive the docking of BstRNASer to BsTrmK in complex with its methyl-donor cofactor S-adenosyl-L-methionine (SAM). In this model, validated by methyltransferase activity assays on BsTrmK mutants, both domains of BsTrmK participate in tRNA binding. BsTrmK recognises tRNA with very few structural changes in both partner, the non-Watson-Crick R13-A22 base-pair positioning the A22 N1-atom close to the SAM methyl group.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Solute Transport Proteins and the Outer Membrane Protein NmpC Contribute to Heat Resistance of Escherichia coli AW1.7▿

This study aimed to elucidate determinants of heat resistance in Escherichia coli by comparing the composition of membrane lipids, as well as gene expression, in heat-resistant E. coli AW1.7 and heat-sensitive E. coli GGG10 with or without heat shock. The survival of E. coli AW1.7 at late exponential phase was 100-fold higher than that of E. coli GGG10 after incubation at 60°C for 15 min. The cytoplasmic membrane of E. coli AW1.7 contained a higher proportion of saturated and cyclopropane fatty acids than that of E. coli GGG10. Microarray hybridization of cDNA libraries obtained from exponentially growing or heat-shocked cultures was performed to compare gene expression in these two strains. Expression of selected genes from different functional groups was quantified by quantitative PCR. DnaK and 30S and 50S ribosomal subunits were overexpressed in E. coli GGG10 relative to E. coli AW1.7 upon heat shock at 50°C, indicating improved ribosome stability. The outer membrane porin NmpC and several transport proteins were overexpressed in exponentially growing E. coli AW1.7. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of membrane properties confirmed that NmpC is present in the outer membrane of E. coli AW1.7 but not in that of E. coli GGG10. Expression of NmpC in E. coli GGG10 increased survival at 60°C 50- to 1,000-fold. In conclusion, the outer membrane porin NmpC contributes to heat resistance in E. coli AW1.7, but the heat resistance of this strain is dependent on additional factors, which likely include the composition of membrane lipids, as well as solute transport proteins