Tranexamic acid for patients with nasal haemorrhage (epistaxis)

Background Epistaxis (nosebleed) most commonly affects children and the elderly. The majority of episodes are managed at home with simple measures. In more severe cases medical intervention is required to either cauterise the bleeding vessel, or to pack the nose with various materials. Tranexamic acid is used in a number of clinical settings to stop bleeding by preventing clot breakdown (fibrinolysis). It may have a role in the management of epistaxis as an adjunct to standard treatments, reducing the need for further intervention. Objectives To determine the effects of tranexamic acid (oral, intravenous or topical) compared with placebo, no additional intervention or any other haemostatic agent in the management of patients with epistaxis. Search methods The Cochrane ENT Information Specialist searched the Cochrane ENT Register (via CRS Web); Central Register of Controlled Trials (CENTRAL) (via CRS Web); PubMed; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 29 October 2018. Selection criteria Randomised controlled trials (RCTs) of tranexamic acid (in addition to usual care) compared with usual care plus placebo, usual care alone or usual care plus any other haemostatic agent, to control epistaxis in adults or children. Data collection and analysis We used the standard methodological procedures expected by Cochrane. The primary outcomes were control of epistaxis: re‐bleeding (as measured by the proportion of patients re‐bleeding within a period of up to 10 days) and significant adverse effects (seizures, thromboembolic events). Secondary outcomes were control of epistaxis as measured by the time to stop initial bleeding (the proportion of patients whose bleeding is controlled within a period of up to 30 minutes); severity of re‐bleeding (as measured by (a) the proportion of patients requiring any further intervention and (b) the proportion of patients requiring blood transfusion); length of hospital stay and other adverse effects. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics. Main results We included six RCTs (692 participants). The overall risk of bias in the studies was low. Two studies assessed oral administration of tranexamic acid, given regularly over several days, and compared it to placebo. In the other four studies, a single application of topical tranexamic acid was compared with placebo (one study) and a combination of epinephrine and lidocaine or phenylephrine (three studies). All participants were adults. Tranexamic acid versus placebo For our primary outcome, control of epistaxis: re‐bleeding (proportion re‐bleeding within 10 days), we were able to pool data from three studies. The pooled result demonstrated a benefit of tranexamic acid compared to placebo, the risk of re‐bleeding reducing from 67% to 47% (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.56 to 0.90; three studies; 225 participants; moderate‐quality evidence). When we compared the effects of oral and topical tranexamic acid separately the risk of re‐bleeding with oral tranexamic acid reduced from 69% to 49%, RR 0.73 (95% CI 0.55 to 0.96; two studies, 157 participants; moderate‐quality evidence) and with topical tranexamic acid it reduced from 66% to 43%, RR 0.66 (95% CI 0.41 to 1.05; single study, 68 participants). We rated the quality of evidence provided by the single study as low, therefore it is uncertain whether topical tranexamic acid is effective in stopping bleeding in the 10‐day period after a single application. No study specifically sought to identify and report our primary outcome: significant adverse effects (i.e. seizures, thromboembolic events). The secondary outcome time to stop initial bleeding (proportion with bleeding controlled within 30 minutes) was measured in one study using topical tranexamic acid and there was no evidence of a difference at 30 minutes (RR 0.79, 95% CI 0.56 to 1.11; 68 participants; low‐quality evidence). No studies reported the proportion of patients requiring any further intervention (e.g. repacking, surgery, embolisation). One study of oral tranexamic acid reported the proportion of patients requiring blood transfusion and found no difference between groups: 5/45 (11%) versus 6/44 (14%) (RR 0.81, 95% CI 0.27 to 2.48; 89 participants; low‐quality evidence). Two studies reported hospital length of stay. One study reported a significantly shorter stay in the oral tranexamic acid group (mean difference (MD) ‐1.60 days, 95% CI ‐2.49 to ‐0.71; 68 participants). The other study found no evidence of a difference between the groups. Tranexamic acid versus other haemostatic agents When we pooled the data from three studies the proportion of patients whose bleeding stopped within 10 minutes was significantly higher in the topical tranexamic acid group compared to the group receiving another haemostatic agent (70% versus 30%: RR 2.35, 95% CI 1.90 to 2.92; 460 participants) (moderate‐quality evidence). Adverse effects across all studies Five studies recorded 'adverse effects' in a general way. None found any difference between the groups in the occurrence of minor adverse effects (e.g. mild nausea and diarrhoea, 'bad taste' of gel). In one study a patient developed a superficial thrombophlebitis of both legs following discharge, however it is not reported in which group this occurred. No "other serious adverse effect" was reported in any study. Authors' conclusions We found moderate‐quality evidence that there is probably a reduction in the risk of re‐bleeding with the use of either oral or topical tranexamic acid in addition to usual care in adult patients with epistaxis, compared to placebo with usual care. However, the quality of evidence relating solely to topical tranexamic acid was low (one study only), so we are uncertain whether or not topical tranexamic acid is effective in stopping bleeding in the 10‐day period after a single application. We found moderate‐quality evidence that topical tranexamic acid is probably better than other topical agents in stopping bleeding in the first 10 minutes. There have been only three RCTs on this subject since 1995. Since then there have been significant changes in nasal cauterisation and packing techniques (for example, techniques including nasal endoscopy and more invasive approaches such as endoscopic sphenopalatine artery ligation). New trials would inform us about the effectiveness of tranexamic acid in light of these developments

The Cochrane Ear, Nose and Throat Disorders Group.

The Cochrane Ear, Nose and Throat Disorders Group is part of The Cochrane Collaboration and produces high-quality systematic reviews of interventions in otolaryngology and a register of all published and unpublished randomized and controlled trials in otolaryngology-head and neck surgery. The editorial base in Oxford provides support for volunteer reviewers who are practitioners, epidemiologists, or patients wishing to undertake reviews, and these are published in The Cochrane Library (www.thecochranelibrary.com). Participation and group membership is free and open to all. We describe here how the group is organized, how it undertakes its core activities, and how you, the reader, can become involved

Tranexamic acid for patients with nasal haemorrhage (epistaxis)

Background Epistaxis (nosebleed) most commonly affects children and the elderly. The majority of episodes are managed at home with simple measures. In more severe cases medical intervention is required to either cauterise the bleeding vessel, or to pack the nose with various materials. Tranexamic acid is used in a number of clinical settings to stop bleeding by preventing clot breakdown (fibrinolysis). It may have a role in the management of epistaxis as an adjunct to standard treatments, reducing the need for further intervention. Objectives To determine the effects of tranexamic acid (oral, intravenous or topical) compared with placebo, no additional intervention or any other haemostatic agent in the management of patients with epistaxis. Search methods The Cochrane ENT Information Specialist searched the Cochrane ENT Register (via CRS Web); Central Register of Controlled Trials (CENTRAL) (via CRS Web); PubMed; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 29 October 2018. Selection criteria Randomised controlled trials (RCTs) of tranexamic acid (in addition to usual care) compared with usual care plus placebo, usual care alone or usual care plus any other haemostatic agent, to control epistaxis in adults or children. Data collection and analysis We used the standard methodological procedures expected by Cochrane. The primary outcomes were control of epistaxis: re‐bleeding (as measured by the proportion of patients re‐bleeding within a period of up to 10 days) and significant adverse effects (seizures, thromboembolic events). Secondary outcomes were control of epistaxis as measured by the time to stop initial bleeding (the proportion of patients whose bleeding is controlled within a period of up to 30 minutes); severity of re‐bleeding (as measured by (a) the proportion of patients requiring any further intervention and (b) the proportion of patients requiring blood transfusion); length of hospital stay and other adverse effects. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics. Main results We included six RCTs (692 participants). The overall risk of bias in the studies was low. Two studies assessed oral administration of tranexamic acid, given regularly over several days, and compared it to placebo. In the other four studies, a single application of topical tranexamic acid was compared with placebo (one study) and a combination of epinephrine and lidocaine or phenylephrine (three studies). All participants were adults. Tranexamic acid versus placebo For our primary outcome, control of epistaxis: re‐bleeding (proportion re‐bleeding within 10 days), we were able to pool data from three studies. The pooled result demonstrated a benefit of tranexamic acid compared to placebo, the risk of re‐bleeding reducing from 67% to 47% (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.56 to 0.90; three studies; 225 participants; moderate‐quality evidence). When we compared the effects of oral and topical tranexamic acid separately the risk of re‐bleeding with oral tranexamic acid reduced from 69% to 49%, RR 0.73 (95% CI 0.55 to 0.96; two studies, 157 participants; moderate‐quality evidence) and with topical tranexamic acid it reduced from 66% to 43%, RR 0.66 (95% CI 0.41 to 1.05; single study, 68 participants). We rated the quality of evidence provided by the single study as low, therefore it is uncertain whether topical tranexamic acid is effective in stopping bleeding in the 10‐day period after a single application. No study specifically sought to identify and report our primary outcome: significant adverse effects (i.e. seizures, thromboembolic events). The secondary outcome time to stop initial bleeding (proportion with bleeding controlled within 30 minutes) was measured in one study using topical tranexamic acid and there was no evidence of a difference at 30 minutes (RR 0.79, 95% CI 0.56 to 1.11; 68 participants; low‐quality evidence). No studies reported the proportion of patients requiring any further intervention (e.g. repacking, surgery, embolisation). One study of oral tranexamic acid reported the proportion of patients requiring blood transfusion and found no difference between groups: 5/45 (11%) versus 6/44 (14%) (RR 0.81, 95% CI 0.27 to 2.48; 89 participants; low‐quality evidence). Two studies reported hospital length of stay. One study reported a significantly shorter stay in the oral tranexamic acid group (mean difference (MD) ‐1.60 days, 95% CI ‐2.49 to ‐0.71; 68 participants). The other study found no evidence of a difference between the groups. Tranexamic acid versus other haemostatic agents When we pooled the data from three studies the proportion of patients whose bleeding stopped within 10 minutes was significantly higher in the topical tranexamic acid group compared to the group receiving another haemostatic agent (70% versus 30%: RR 2.35, 95% CI 1.90 to 2.92; 460 participants) (moderate‐quality evidence). Adverse effects across all studies Five studies recorded 'adverse effects' in a general way. None found any difference between the groups in the occurrence of minor adverse effects (e.g. mild nausea and diarrhoea, 'bad taste' of gel). In one study a patient developed a superficial thrombophlebitis of both legs following discharge, however it is not reported in which group this occurred. No "other serious adverse effect" was reported in any study. Authors' conclusions We found moderate‐quality evidence that there is probably a reduction in the risk of re‐bleeding with the use of either oral or topical tranexamic acid in addition to usual care in adult patients with epistaxis, compared to placebo with usual care. However, the quality of evidence relating solely to topical tranexamic acid was low (one study only), so we are uncertain whether or not topical tranexamic acid is effective in stopping bleeding in the 10‐day period after a single application. We found moderate‐quality evidence that topical tranexamic acid is probably better than other topical agents in stopping bleeding in the first 10 minutes. There have been only three RCTs on this subject since 1995. Since then there have been significant changes in nasal cauterisation and packing techniques (for example, techniques including nasal endoscopy and more invasive approaches such as endoscopic sphenopalatine artery ligation). New trials would inform us about the effectiveness of tranexamic acid in light of these developments

Cochrane ENT in the Covid-19 pandemic: using our expertise and collaborating effectively

The 2020 COVID-19 pandemic has presented enormous challenges for healthcare systems globally. At Cochrane ENT (ent.cochrane.org) we wanted to see how we could use our particular skills and resources to assist professionals and patients in our own clinical field

The major histocompatibility complex class II Ea promoter requires TFIID binding to an initiator sequence.

The major histocompatibility complex (MHC) class II Ea promoter is dependent on the presence of conserved upstream X and Y boxes and of initiator (Inr) sequences. In vitro transcription analysis of the Inr region with linker-scanning mutants pinpoints a functionally essential element that shows homology to the terminal deoxynucleotidyltransferase (TdT) Inr; contrary to the TdT Inr and other Inrs identified so far, the key sequence, between positions +5 and +12, is located within a transcribed area. Swapping the TdT sequence into the corresponding Ea position leads to a fivefold increase in transcription rate, without altering start site selection. Inr-binding proteins LBP-1/CP2 and TIP--a TdT Inr-binding protein unrelated to YY1--recognize the Ea Inr; they interact with overlapping yet distinct sequences around the Cap site, but their binding does not coincide with Ea Inr activity. A good correlation is, rather, found with binding of immunopurified holo-TFIID to this element. TFIID interacts both with Ea TATA-like and Inr sequences, but only the latter is functionally relevant. Unlike TBP, TFIID binds in the absence of TFIIA, indicating a stabilizing role for TBP-associated factors in Ea promoter recognition. Sequence comparison with other mouse and human MHC class II promoters suggests a common mechanism of start site(s) selection for the MHC class II gene family

Cloning and expression of human NF-YC

The CCAAT box is an important element in eukaryotic promoters and NF-Y (CBF) is a conserved heterotrimeric protein binding to it. Two subunits, NF-YB and NF-YC, contain a histone-like motif. We cloned the complete cDNA coding for the human NF-YC gene. The ORF codes for a 335 aa protein that shows virtual identity to the rat sequence, confirming the stunning invariance of NF-Y genes across species. We expressed and purified the yeast homology domain of NF-YC in bacteria and performed EMSA together with the corresponding conserved domains of NF-YA and NF-YB, obtaining a CCAAT-binding mini-NF-Y. We evaluated the expression of NF-YC and found that mRNA levels are similar in different human tissues except in testis

CCAAT binding NF-Y-TBP interactions: NF-YB and NF-YC require short domains adjacent to their histone fold motifs for association with TBP basic residues.

Both the TATA and CCAAT boxes are widespread promoter elements and their binding proteins, TBP and NF-Y, are extremely conserved in evolution. NF-Y is composed of three subunits, NF-YA, NF-YB and NF-YC, all necessary for DNA binding. NF-YB and NF-YC contain a putative histone-like motif, a domain also present in TBP-associated factors (TAFIIs) and in the subunits of the transcriptional repressor NC2. Immunopurification of holo-TFIID with anti-TBP and anti-TAFII100 antibodies indicates that a fraction of NF-YB associates with TFIID in the absence of NF-YA. Sedimentation velocity centrifugation experiments confirm that two pools of NF-YB, and most likely NF-YC, exist: one associated with NF-YA and binding to the CCAAT box; another involved in high molecular weight complexes. We started to dissect NF-Y-TFIID interactions by showing that: (i) NF-YB and NF-YC interact with TBP in solution, both separately and once bound to each other; (ii) short stretches of both NF-YB and NF-YC located within the evolutionary conserved domains, adjacent to the putative histone fold motifs, are necessary for TBP binding; (iii) TBP single amino acid mutants in the HS2 helix, previously shown to be defective in NC2 binding, are also unable to bind NF-YB and NF-YC

The Control System of CERN Accelerators Vacuum (LS1 Activities and New Developments)

After 3 years of operation, the LHC entered its first Long Shutdown period (LS1), in February 2013 [1]. Major consolidation and maintenance works are being performed across the whole CERN’s Accelerator chain, in order to prepare the LHC to restart at higher energy, in 2015. The injector chain shall resume earlier, in mid-14. We report about the on-going vacuum-controls projects. Some of them concern the renovation of the controls of certain machines; others are associated with the consolidations of the vacuum systems of LHC and its injectors; and a few are completely new installations. ue to the wide age-span of the existing vacuum installations, there is a mix of design philosophies and of control-equipment generations. The renovations and the novel projects offer an opportunity to improve the uniformity and efficiency of vacuum controls by: reducing the number of equipment versions with similar functionality; identifying, naming, labelling, and documenting all pieces of equipment; homogenizing the control architectures, while converging to a common software framework

Endoplasmic Reticulum Stress-Induced Formation of Transcription Factor Complex ERSF Including NF-Y (CBF) and Activating Transcription Factors 6α and 6β That Activates the Mammalian Unfolded Protein Response

The levels of molecular chaperones and folding enzymes in the endoplasmic reticulum (ER) are controlled by a transcriptional induction process termed the unfolded protein response (UPR). The mammalian UPR is mediated by the cis-acting ER stress response element (ERSE), the consensus sequence of which is CCAAT-N(9)-CCACG. We recently proposed that ER stress response factor (ERSF) binding to ERSE is a heterologous protein complex consisting of the constitutive component NF-Y (CBF) binding to CCAAT and an inducible component binding to CCACG and identified the basic leucine zipper-type transcription factors ATF6α and ATF6β as inducible components of ERSF. ATF6α and ATF6β produced by ER stress-induced proteolysis bind to CCACG only when CCAAT is bound to NF-Y, a heterotrimer consisting of NF-YA, NF-YB, and NF-YC. Interestingly, the NF-Y and ATF6 binding sites must be separated by a spacer of 9 bp. We describe here the basis for this strict requirement by demonstrating that both ATF6α and ATF6β physically interact with NF-Y trimer via direct binding to the NF-YC subunit. ATF6α and ATF6β bind to the ERSE as a homo- or heterodimer. Furthermore, we showed that ERSF including NF-Y and ATF6α and/or β and capable of binding to ERSE is indeed formed when the cellular UPR is activated. We concluded that ATF6 homo- or heterodimers recognize and bind directly to both the DNA and adjacent protein NF-Y and that this complex formation process is essential for transcriptional induction of ER chaperones