786 research outputs found
A clinical audit of the utilisation of red cell products in elective total hip replacement surgery
Background. Previous studies have documented a marked variation in transfusion practice for total hip replacement (THR)Β surgery. Objective. To audit red cell product utilisation for THR at two Western Cape tertiary referral hospitals (HY and HG).Β Methods. The folders of 207 consecutive patients undergoing elective THR surgery from January 2013 to December 2013 wereΒ reviewed. Information relating to age, sex, clinical observations, indications for surgery, pre- and postoperativeΒ haemoglobin (Hb) values, comorbidities, length of hospital stay and transfusion history was recorded.Results. The transfusion rate at HY (41.6%) was significantly higher than that at HG (10.0%). The mean postoperative Hb in the transfused patients at HG was 8.3 g/dL v. 9.1 g/dL at HY. Females had a significantly higher transfusion rate (33.0%) than males (15.0%) (p<0.05), and the mean age of transfused patients was significantly greater than that of untransfused patientsΒ (p<0.005). Although patients with comorbidities had a higher transfusion rate than those without, this did not reach statisticalΒ significance. Of 120 patients with complete data, 113 (94.2%) had a blood bank order, of which the vast majority, 102/113Β (90.3%), were group-and-screen (G&S) requests; 29/113 (25.7%) were converted to a full crossmatch.Conclusions. Overall, the transfusion rate for both hospitals was 25.8%, which is well within published rates. A guideline Hb trigger of 8.0 g/dL is recommended as per published guidelines, with the caveat that the clinical judgement of the attending clinician whether a transfusion is indicated is paramount. Causes of preoperative anaemia should be investigated and treated. Routine cross-matching preoperatively is unnecessary, and a G&S order is sufficient
Towards Protein Crystallization as a Process Step in Downstream Processing of Therapeutic Antibodies: Screening and Optimization at Microbatch Scale
Crystallization conditions of an intact monoclonal IgG4 (immunoglobulin G, subclass 4) antibody were established in vapor diffusion mode by sparse matrix screening and subsequent optimization. The procedure was transferred to microbatch conditions and a phase diagram was built showing surprisingly low solubility of the antibody at equilibrium. With up-scaling to process scale in mind, purification efficiency of the crystallization step was investigated. Added model protein contaminants were excluded from the crystals to more than 95%. No measurable loss of Fc-binding activity was observed in the crystallized and redissolved antibody. Conditions could be adapted to crystallize the antibody directly from concentrated and diafiltrated cell culture supernatant, showing purification efficiency similar to that of Protein A chromatography. We conclude that crystallization has the potential to be included in downstream processing as a low-cost purification or formulation step
Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay
The decay channel
is studied using a sample of events collected
by the BESIII experiment at BEPCII. A strong enhancement at threshold is
observed in the invariant mass spectrum. The enhancement can be fit
with an -wave Breit-Wigner resonance function with a resulting peak mass of
and a
narrow width that is at the 90% confidence level.
These results are consistent with published BESII results. These mass and width
values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
Drug transporters: recent advances concerning BCRP and tyrosine kinase inhibitors
Multidrug resistance is often associated with the (over)expression of drug efflux transporters of the ATP-binding cassette (ABC) protein family. This minireview discusses the role of one selected ABC-transporter family member, the breast cancer resistance protein (BCRP/ABCG2), in the (pre)clinical efficacy of novel experimental anticancer drugs, in particular tyrosine kinase inhibitors
Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0βD*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4ββfb-1 collected at the Ξ₯(4S) resonance during 1999β2000, we have reconstructed 38 candidate signal events in the mode B0βD*+D*- with an estimated background of 6.2Β±0.5 events. From these events, we determine the branching fraction to be B(B0βD*+D*-)=[8.3Β±1.6(stat)Β±1.2(syst)]Γ10-4. The measured CP-odd fraction of the final state is 0.22Β±0.18(stat)Β±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at βs=10.6 GeV
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qqΜ
continuum events near the Ξ₯(4S) resonance are presented. Using 20.8 fb-1 of data on the Ξ₯(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(BβDs+X)=(10.93Β±0.19Β±0.58Β±2.73)% and B(BβDs*+X)=(7.9Β±0.8Β±0.7Β±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+βΟΟ+ branching fraction uncertainty. The production cross sections Ο(e+e-βDs+X)ΓB(Ds+βΟΟ+)=7.55Β±0.20Β±0.34pb and Ο(e+e-βDs*Β±X)ΓB(Ds+βΟΟ+)=5.8Β±0.7Β±0.5pb are measured at center-of-mass energies about 40 MeV below the Ξ₯(4S) mass. The branching fractions Ξ£B(BβDs(*)+D(*))=(5.07Β±0.14Β±0.30Β±1.27)% and Ξ£B(BβDs*+D(*))=(4.1Β±0.2Β±0.4Β±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4Β±0.1Β±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
Search for rare quark-annihilation decays, B --> Ds(*) Phi
We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context
of the Standard Model, these decays are expected to be highly suppressed since
they proceed through annihilation of the b and u-bar quarks in the B- meson.
Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected
with the BABAR detector at SLAC. We find no evidence for these decays, and we
set Bayesian 90% confidence level upper limits on the branching fractions BF(B-
--> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results
are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid
Communications
Clathrin- and Dynamin-Independent Endocytosis of FGFR3 β Implications for Signalling
Endocytosis of tyrosine kinase receptors can influence both the duration and the specificity of the signal emitted. We have investigated the mechanisms of internalization of fibroblast growth factor receptor 3 (FGFR3) and compared it to that of FGFR1 which is internalized predominantly through clathrin-mediated endocytosis. Interestingly, we observed that FGFR3 was internalized at a slower rate than FGFR1 indicating that it may use a different endocytic mechanism than FGFR1. Indeed, after depletion of cells for clathrin, internalization of FGFR3 was only partly inhibited while endocytosis of FGFR1 was almost completely abolished. Similarly, expression of dominant negative mutants of dynamin resulted in partial inhibition of the endocytosis of FGFR3 whereas internalization of FGFR1 was blocked. Interfering with proposed regulators of clathrin-independent endocytosis such as Arf6, flotillin 1 and 2 and Cdc42 did not affect the endocytosis of FGFR1 or FGFR3. Furthermore, depletion of clathrin decreased the degradation of FGFR1 resulting in sustained signalling. In the case of FGFR3, both the degradation and the signalling were only slightly affected by clathrin depletion. The data indicate that clathrin-mediated endocytosis is required for efficient internalization and downregulation of FGFR1 while FGFR3, however, is internalized by both clathrin-dependent and clathrin-independent mechanisms
Matrix Metalloproteinase-9 (MMP-9) polymorphisms in patients with cutaneous malignant melanoma
BACKGROUND: Cutaneous Malignant Melanoma causes over 75% of skin cancer-related deaths, and it is clear that many factors may contribute to the outcome. Matrix Metalloproteinases (MMPs) play an important role in the degradation and remodeling of the extracellular matrix and basement membrane that, in turn, modulate cell division, migration and angiogenesis. Some polymorphisms are known to influence gene expression, protein activity, stability, and interactions, and they were shown to be associated with certain tumor phenotypes and cancer risk. METHODS: We tested seven polymorphisms within the MMP-9 gene in 1002 patients with melanoma in order to evaluate germline genetic variants and their association with progression and known risk factors of melanoma. The polymorphisms were selected based on previously published reports and their known or potential functional relevance using in-silico methods. Germline DNA was then genotyped using pyrosequencing, melting temperature profiles, heteroduplex analysis, and fragment size analysis. RESULTS: We found that reference alleles were present in higher frequency in patients who tend to sunburn, have family history of melanoma, higher melanoma stage, intransit metastasis and desmoplastic melanomas among others. However, after adjustment for age, sex, phenotypic index, moles, and freckles only Q279R, P574R and R668Q had significant associations with intransit metastasis, propensity to tan/sunburn and primary melanoma site. CONCLUSION: This study does not provide strong evidence for further investigation into the role of the MMP-9 SNPs in melanoma progression
Immune Response to Lactobacillus plantarum Expressing Borrelia burgdorferi OspA Is Modulated by the Lipid Modification of the Antigen
Over the past decade there has been increasing interest in the use of lactic acid bacteria as mucosal delivery vehicles for vaccine antigens, microbicides and therapeutics. We investigated the mechanism by which a mucosal vaccine based in recombinant lactic acid bacteria breaks the immunological tolerance of the gut in order to elicit a protective immune response.We analyzed how the lipid modification of OspA affects the localization of the antigen in our delivery vehicle using a number of biochemistry techniques. Furthermore, we examined how OspA-expressing L. plantarum breaks the oral tolerance of the gut by stimulating human intestinal epithelial cells, peripheral blood mononuclear cells and monocyte derived dendritic cells and measuring cytokine production. We show that the leader peptide of OspA targets the protein to the cell envelope of L. plantarum, and it is responsible for protein export across the membrane. Mutation of the lipidation site in OspA redirects protein localization within the cell envelope. Further, we show that lipidated-OspA-expressing L. plantarum does not induce secretion of the pro-inflammatory cytokine IL-8 by intestinal epithelial cells. In addition, it breaks oral tolerance of the gut via Th1/Th2 cell mediated immunity, as shown by the production of pro- and anti-inflammatory cytokines by human dendritic cells, and by the production of IgG2a and IgG1 antibodies, respectively.Lipid modification of OspA expressed in L. plantarum modulates the immune response to this antigen through a Th1/Th2 immune response
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