By F. Dan. Saint Joseph College.
Side effects in these studies were comparable to the placebo arms purchase 2mg imodium with mastercard. The 903 trial showed at least equivalent potency with a significantly reduced incidence of polyneuropathy and lipid changes compared to d4T (Gallant 2004) cheap imodium 2 mg amex. It has been shown that phosphorylated tenofovir has a low affinity for mitochondrial poly- merase (Suo 1998) cheap imodium 2mg free shipping. As a result of this convincing clinical data best imodium 2mg, the drug is still among the most widely used agents in antiretroviral therapies. In the 934 study, TDF+FTC were significantly better than AZT+3TC (Gallant 2006, Arribas 2008), particularly due to improved tolerability. Furthermore, tenofovir can help improve lipoatrophy and dyslipidemia (see chapter 6. Another advantage is its efficacy against the hepatitis B virus, which resulted in the licensing of this drug for HBV monoinfection. Other areas of use are in vertical prevention and pre-exposure prophylaxis (see appropriate chapters). Some problems have come to light with the more extensive use of TDF. An unfavorable interaction with atazanavir exists that calls for being boosted with ritonavir (Taburet 2004). Efficacy may also be limited in some triple nuke regimens (see section on Triple Nukes). However, the main problem today with tenofovir is its potential risk of nephrotoxicity (see chapter on HIV and Renal Function). Nephrotoxicity is reflected by a mostly mild disturbance of renal function (Review: Hall 2011). Fortunately, severe dysfunctions are very rare (Gallant 2008, Scherzer 2012). In a Swiss cohort trial, 46 out of 2,592 patients (1. The risk of renal toxicity seems to be higher when tenofovir is combined with boosted PIs (Young 2012). Renal failure can also be observed in the setting of Fanconi syndrome, a defect of the proximal tubular transport (Schaaf 2003, Hall 2011). Patients with renal disease should either not be treated with tenofovir, or receive a lower dose (see chapter on Drugs). Elderly patients and patients with low body weight are particularly at risk (Crane 2006). However, it is so far impossible to predict who is at risk of developing renal dysfunction. According to current data, because it is taken by such a large number of patients, it is important to remain alert and to regularly check renal function of patients on tenofovir, especially of those on long-term therapy. Tenofovir is also associated with bone damage such as osteomalacia. There is no doubt, that during the next years, many patients will replace TDF by tenofovir alafenamide (TAF, see also next chapter). TAF is a novel prodrug of teno- fovir which has a different structure to TDF, reaching adequate tenofovir concen- trations in cells at a much lower dose, which has less potential to harm kidney and bone tissue. Gilead has applied for approval (or plans to do so) of different TAF-inclu- sive versions of Truvada, Complera and Stribild. The choice of nuke backbones Until now, all classical ART regimens have contained two nucleoside or nucleotide analogs (the “nuke backbone”). This is mainly historical: nucleoside analogs were the first HIV drugs, and when PIs appeared years later, treatment with two nukes was standard. As knowledge has grown about the mitochondrial toxicity of some 76 ART NRTIs, this concept is now being questioned by an increasing number of experts (see section on Nuke-Sparing). However, data on combinations without NRTIs are still limited, and there are currently no recommendations for such strategies. The most frequently used backbones are TDF+FTC, and with some limitations, ABC+3TC. Both are available in fixed-dose combinations that can be taken once daily. AZT+3TC, the long-standing standard backbone in the nineties, is now considered an alternative. In the Gilead 903 Study, the combination TDF+3TC was not only as virologically effective as d4T+3TC, but was also much better tolerated (Gallant 2004). Since the introduction of FTC and the fixed-dose combination tablets of Truvada, Atripla, and, more recently, Complera and Stribild, tenofovir is almost always co-admin- istered with FTC, and TDF+FTC is the most frequently-used NRTI backbone. In the Gilead 934 Study (Gallant 2006), enrolling 509 ART-naïve patients, TDF+FTC was tested against AZT+3TC in an open-label design (all patients also received efavirenz). At 48 weeks, a larger proportion of patients in the TDF+FTC arm reached less than 50 copies/ml (80% versus 70%). This was even true for patients with a higher base- line viral load. The significant differences were primarily related to the poorer tol- erability of Combivir, which often resulted in the discontinuation of therapy (9% versus 4%). Virological failure and resistance mutations were approximately equal in both arms and were infrequent. After 144 weeks, lipoatrophy was less frequent in the TDF+FTC arm (Arribas 2008). In the near future, tenofovir alafenamide (TAF), a novel prodrug of tenofovir, will probably replace TDF in many patients. There is no doubt that TDF+FTC or TAF+FTC will remain the most frequently used backbone during the coming years. ABC+3TC Another frequent backbone is ABC+3TC, which is also available in a fixed-dose combination known either as Kivexa or Epzicom. The double-blind randomized CNA30024 Study showed the non-inferiority of ABC+3TC in comparison to Combivir (DeJesus 2004). In the ABCDE Study, ABC+3TC had the same efficacy as d4T+3TC, but had less toxicity (Podzamczer 2006). Over the last few years, ABC+3TC has been compared to TDF+FTC in several ran- domized studies of therapy-naïve patients (ASSERT, ACTG 5202, HEAT), as well as in treatment-experienced patients (BICOMBO, STEAL), see also the following Table. Overview of antiretroviral agents 77 As shown there, data is not consistent. ABC+3TC were equivalent to TDF+FTC in HEAT and STEAL.
Mansour A imodium 2 mg with amex, Abou-Ezzi G discount 2 mg imodium, Sitnicka E imodium 2mg generic, Jacobsen SE cheap imodium 2 mg with mastercard, Wakkach A, Fellowship. Osteoclasts promote the formation of hematopoietic stem cell niches in the bone marrow. Nonmyelinating Schwann cells maintain hematopoietic stem cell hibernation in the bone marrow niche. PTH expands short-term murine ceives royalties from Fate Therapeutics. Naveiras O, Nardi V, Wenzel PL, Hauschka PV, Fahey F, Daley GQ. Bone-marrow adipocytes as negative regulators of the haematopoietic Correspondence microenvironment. Calvi, MD, Professor of Medicine, Pharmacology and 22. Haematopoietic Physiology, Department of Neurologic Surgery, Wilmot Cancer stem cell release is regulated by circadian oscillations. Ave, Box 693, Rochester, NY 14642; Phone: (585)275-5011; Fax: 23. Bromberg O, Frisch BJ, Weber JM, Porter RL, Civitelli R, Calvi LM. Osteoblastic N-cadherin is not required for microenvironmental support and regulation of hematopoietic stem and progenitor cells. Physiologic corticosterone myelodysplastic syndromes using a novel claims-based algorithm: high oscillations regulate murine hematopoietic stem/progenitor cell prolif- number of uncaptured cases by cancer registries. Lindquist KJ, Danese MD, Mikhael J, Knopf KB, Grifﬁths RI. Oestrogen increases haematopoietic care utilization and mortality among elderly patients with myelodysplas- stem-cell self-renewal in females and during pregnancy. Nice neighborhood: emerging concepts of the stem cell 26. Targeted disruption of Cbfa1 results 2014;508(7495):269-273. Identiﬁcation of the haematopoietic stem osteocytes through Gsalpha-dependent signaling. Mesenchymal and microenvironment leads to myeloproliferative disease. CXCL12 in early mesenchymal myeloproliferative syndrome caused by retinoic acid receptor gamma progenitors is required for haematopoietic stem-cell maintenance. Haematopoietic stem cells and early lymphoid an activating beta-catenin mutation in osteoblasts. Kiel MJ, Yilmaz OH, Iwashita T, Terhorst C, Morrison SJ. Bone marrow graft in man and reveal endothelial niches for stem cells. Hinterberger W, Rowlings PA, Hinterberger-Fischer M, et al. Results of of hematopoiesis is dependent on VEGFR2-mediated regeneration of transplanting bone marrow from genetically identical twins into patients sinusoidal endothelial cells. Idiopathic aplastic anemia: Diagnosis and haematopoietic stem cell quiescence. Hoffman R, Zanjani ED, Lutton JD, Zalusky R, Wasserman LR. Suppression of erythroid-colony formation by lymphocytes from pa- 1991;78(1):55-62. Risitano AM, Maciejewski JP, Green S, Plasilova M, Zeng W, Young normal human adult bone marrow. In-vivo dominant immune responses in aplastic anaemia: molecular 16. Monocytes-macrophages that tracking of putatively pathogenetic T-cell clones by TCR beta-CDR3 express alpha-smooth muscle actin preserve primitive hematopoietic sequencing. Differential gene expression proﬁle associated Hematology 2014 75 with the abnormality of bone marrow mesenchymal stem cells in 59. Vascular endothelial cell growth factor is an autocrine aplastic anemia. PTH expands short-term murine leukemia progenitor formation in myelodysplastic syndromes. Li JY, Adams J, Calvi LM, Lane TF, Weitzmann MN, Paciﬁci R. In vivo imaging of Treg cells bone marrow of myelodysplastic syndromes transforming to overt providing immune privilege to the haematopoietic stem-cell niche. Bone progenitor dysfunc- inducible gelatinase B/matrix metalloproteinase-9 in monocytes from tion induces myelodysplasia and secondary leukaemia. Kerbauy DM, Lesnikov V, Torok-Storb B, Bryant E, Deeg HJ. Mesenchymal stem cells from Shwachman-Diamond syndrome patients display normal functions and transplantation of hematopoietic and stromal cells. Establishment of a the reconstitution of exogenous hematopoietic stem cells in Fancg-/- xenograft model of human myelodysplastic syndromes. Kitagawa M, Yamaguchi S, Takahashi M, Tanizawa T, Hirokawa K, 65. Localization of Fas and Fas ligand in bone marrow cells expressed by marrow stroma inhibits differentiation of 32D cells demonstrating myelodysplasia. Tennant GB, Walsh V, Truran LN, Edwards P, Mills KI, Burnett AK. Effect of Abnormalities of adherent layers grown from bone marrow of patients intravenous coadministration of human stroma cell lines on engraftment with myelodysplasia. Insufﬁcient stromal support in MDS tors in bone marrow sinusoids can organize a hematopoietic microenvi- results from molecular and functional deﬁcits of mesenchymal stromal ronment. Murine xenogeneic models of myelodysplastic syn- 51. Preferential suppression of drome: an essential role for stroma cells. Perivascular support of human gous lymphocytes in patients with trisomy 8 myelodysplastic syndrome. Factors affecting mesenchymal stem cells in multiple human organs. Myelodysplastic cells in patients and reduced expression of activating NK receptors. Marcondes AM, Mhyre AJ, Stirewalt DL, Kim SH, Dinarello CA, Deeg 74.
It is important that the images are assessed by a radiologist or clinician familiar with PML discount 2 mg imodium free shipping. Even then discount 2mg imodium overnight delivery, it is difficult to distinguish PML from HHV-6 infection (Caserta 2004) or HIV leukoencephalopathy (Langford 2002) purchase imodium 2mg line. Clinicoradiological diagnosis is therefore not definitive purchase imodium 2mg free shipping. Generally, if there is no other coinfection, unspecific inflam- matory signs are absent although the total protein content is usually slightly ele- vated. Pleocytosis is rarely seen, and more than 100/3 cells make PML unlikely. Newer PCR methods have a sensitivity of around 80% and a specificity of over 90%. A CSF sample should be sent to a JCV-experi- enced laboratory. PML is very probable in cases of clinicoradiological suspicion and positive JCV PCR. Nevertheless, a negative PCR does not exclude the diagnosis. Levels of JCV viral load may vary significantly and do not correlate with the extent of lesions (Eggers 1999, Garcia 2002, Bossolasco 2005). Unfortunately, JCV PCR is even less useful – many patients with PML have a low or undetectable JCV CSF viral load while on ART (Bossolasco 2005). Stereotactic brain biopsy may become necessary in individual cases. Recently, a consensus statement has been published which establishes detailed criteria for PML diagnosis (Berger 2013). Treatment A specific PML treatment is not available. Foscarnet, interferon, immune stimulants, steroids, camptothecin/topotecan or cytosine arabinoside are not effective (Hall 1998). Unfortunately, this is also the case for the nucleotide analog cidofovir, which is licensed for CMV retinitis. According to an analysis of 370 patients from numerous studies (De Luca 2008), a real benefit has not been proven for cidofovir. Our experiences have been rather disappointing and, in a retrospective analysis of 35 patients, cidofovir was even associated with a poorer prognosis. However, this chiefly reflects the frustration of patients and clinicians – cidofovir was mainly used in cases of progressive disease (Wyen 2004). There may no longer be an argument for the use of cidofovir in PML patients. In recent years, 5-HT2a inhibitors and/or serotonin receptor antagonists have been proposed for PML treatment. It has been shown that the serotonergic receptor 5HT2AR could act as the cellular receptor for JCV on human glial cells (Elphick 2004); the blockade could represent a therapeutic goal. Case studies for some agents such as risperidone and mirtazapine, which block serotonergic receptors, exist already (Verma 2007, Focosi 2007+2008, Cettomai 2009). On the basis of in vitro efficacy (Brickelmeier 2009), mefloquine (a drug that has been used extensively for prophylaxis and treatment of malaria) was tested in a Opportunistic Infections (OIs) 379 clinical trial. In this study on 37 patients with PML, no evidence of anti-JCV activ- ity by mefloquine was found (Clifford 2013). Thus, it should be an absolute priority to optimize ART in cases of PML. Improvement of the JC virus-specific immune response which is often observed within immune reconstitution determines the patient’s further progress to a large extent (Khanna 2009, Marzocchetti 2007+2009, Gasnault 2011). Our early observation that prog- nosis significantly improved on ART (Albrecht 1998) was confirmed by several other groups (Clifford 1999, Dworkin 1999, Gasnault 1999+2008, Berenguer 2003, Khanna 2009). Since synergy between HIV and JCV has been demonstrated in vitro, maximal HIV suppression should be the goal. Although progression of disease has been described with sufficient antiretroviral therapy, ART often remains the only real hope for patients. There is also some evidence that intracerebral penetrating antiretrovi- ral agents such as AZT, FTC, abacavir, nevirapine and lopinavir are more efficient regarding survival of patients with PML (Gasnault 2008). There is one small pilot trial suggesting that an intensive 5-drug ART may improve survival of patients with PML (Gasnault 2011). Treatment/prophylaxis of PML Acute therapy Treatment of choice ART The most important goal is maximal HIV suppression and immune reconstitution! Use intracerebral penetrating agents such as AZT, FTC, abacavir, nevirapine and lopinavir Experimental Only within clinical trials (risperidone? HAART significantly improves the prognosis of patients with HIV-asso- ciated progressive multifocal leukoencephalopathy. Epidemiology and prognosis of AIDS-associated progressive multi- focal leukoencephalopathy in the HAART era. Variable impact on mortality of AIDS-defining events diagnosed during combination antiretroviral therapy: not all AIDS-defining conditions are created equal. Clin Infect Dis 2009, 48:1138-51 Berenguer J, Miralles P, Arrizabalaga J, et al. Clinical course and prognostic factors of progressive multifocal leukoen- cephalopathy in patients treated with highly active antiretroviral therapy. Predictive factors for prolonged survival in AIDS-associated progressive multifocal leukoencephalopathy. PML diagnostic criteria: consensus statement from the AAN Neuroinfectious Disease Section. Prognostic significance of JC virus DNA levels in cerebrospinal fluid of patients with HIV-associated progressive multifocal leukoencephalopathy. Identification and characterization of mefloquine efficacy against JC virus in vitro. Progressive multifocal leukoencephalopathy following rituximab therapy in HIV negative patients: a report of 57 cases from the Research on Adverse Drug Event and Reports (RADAR) project. Human Herpesvirus 6 Infection of the Central Nervous System. Mirtazapine use in human immunodeficiency virus-infected patients with progressive multifocal leukoencephalopathy. HAART improves prognosis in HIV-associated progressive multi- focal leukoen-cephalopathy. A study of mefloquine treatment for progressive multifocal leukoen- cephalopathy: results and exploration of predictors of PML outcomes. J Neurovirol 2013 [Epub ahead of print] De Luca A, Ammassari A, Pezzotti P, et al.
H3K18 and H3K27 acetylase) in relapsed16 and hypodiploid ALL imodium 2mg on line,4 For example imodium 2 mg, alterations of B-lymphoid transcription factor genes are a hallmark of B-ALL purchase imodium 2 mg overnight delivery. PAX5 (paired box 5) alterations are and mutations of SETD2 (a H3K36 trimethylase) purchase imodium 2 mg on line, KDM6A, and MLL2 in relapsed ALL. In contrast, IKAROS gene family tors) and histone modiﬁers (eg, histone demethylase inhibitors and alterations are selectively associated with different subtypes of histone deacetylase inhibitors) are in clinical trials and have been high-risk ALL. Expression of the founding member of this gene shown to be effective in experimental models of ALL. ABL1- class (ABL1, ABL2, CSF1R, PDGFRB); other JAK-STAT (FLT3, IL7R, SH2B3, JAK1/3, TYK2, IL2RB, TSLP); Ras (KRAS, NRAS, NF1, PTPN11, BRAF). Ph-like ALL cases rates equal or inferior to high-risk ALL subtypes, including are BCR-ABL1 negative, but exhibit a gene expression proﬁle BCR-ABL1 positive and MLL-rearranged ALL. Ph-like ALL comprises which may be grouped into several categories (Figure 1, Table 2). These involve increasing prevalence with increasing age. Transcriptome sequenc- ABL1, ABL2, CSF1R (encoding the macrophage colony stimulating ing (RNA-seq) of 15 cases identiﬁed rearrangements of kinase and factor receptor), and PDGRB. Multiple fusion partners have been cytokine receptor genes, including ABL1, EPOR, JAK2, and identiﬁed, but in each case, the fusion involves the kinase as the 3 PDGFRB,5 suggesting that kinase-activating rearrangements are a partner, preserving the kinase domain. The second category is hallmark of Ph-like ALL and that these alterations might be JAK2/EPOR rearrangements. This group comprises JAK2 rearrange- amenable to inhibition with approved TKIs. Kinase rearrangements and therapeutic targets in Ph-like ALL Kinase TKI No. The third category, CRLF2 rearrange- ments, are observed in 50% of Ph-like ALL and are often ERG alterations in ALL accompanied by JAK1 or JAK2 mutations and activation of Five to 10% of B-ALL cases exhibit a distinctive gene expression JAK-STAT signaling. The fourth category is uncommon kinase proﬁle, but harbor few genomic alterations and no recurring alterations. A small number of Ph-like cases have rearrangements chromosomal rearrangement. Approximately 75% of these cases that have only been identiﬁed in single or few cases, including have a focal deletion involving part of the ERG gene,24 which NTRK3 (also rearranged in other tumors), PTK2B, and the Janus encodes an ETS-domain-containing transcription factor that is kinase TYK2. A rearranged in prostate cancer and overexpressed in poor-risk acute minority of Ph-like cases have no other genomic alterations myeloid leukemia. These cases often express an aberrant ERG activating signaling apart from those activating Ras signaling, protein. Of clinical importance, IKZF1 alterations are relatively including NRAS, KRAS, PTPN11, and NF1 mutations. Importantly, common in ERG ALL, but, in contrast to BCR-ABL1 and Ph-like these mutations are not restricted to this subtype of Ph-like ALL and ALL, are not associated with inferior outcome. Intrachromosomal ampliﬁcation of chromosome 21 Data from cell lines expressing kinase fusions and xenografts and Intrachromosomal ampliﬁcation of chromosome 21 (iAMP21) anecdotal case reports indicate that the majority of the Ph-like occurs in up to 2% of childhood B-progenitor ALL, but is rare in fusions induce activation of kinase-signaling pathways that is adult ALL. In trials of childhood ALL in the United Kingdom, amenable to inhibition by available TKIs. Leukemic cells harboring 26 iAMP21 has been associated with older age and poor outcome. ABL1, ABL2, CSF1R, or PDGFRB fusions are sensitive to ABL1 iAMP21 is deﬁned by gain of at least 3 copies of large regions of inhibitors such as imatinib and dasatinib at concentrations similar to chromosome 21, including RUNX1, and is most commonly ob- BCR-ABL1-positive cells. Moreover, multiple patients have been served as the sole chromosomal rearrangement. Less commonly, identiﬁed with high-risk, relapsed, or refractory ALL harboring iAMP21 is observed in other ALL subtypes, including Ph-like and such fusions that have exhibited profound and durable responses to ETV6-RUNX1 ALL. Genome sequencing has demonstrated com- the addition of these agents. Hypodiploidy with 45 chromosomes is associated with poor There are also in vitro and preclinical xenograft data demonstrating outcome and genomic analysis has characterized the 2 main the efﬁcacy of Janus kinase inhibitors in Ph-like cases with subtypes of hypodiploid ALL: near haploid ALL, with 24-31 JAK-STAT activation, particularly those with JAK2 rearrangements chromosomes, frequent Ras activating mutations, and alteration of and IL7R/SH2B3 alterations, but clinical data demonstrating efﬁ- IKZF3, and low hypodiploid ALL, with 32-39 chromosomes, cacy are not yet available. It is likely that many centers will prompt clinical TP53 testing and counseling. Hypodiploid leukemic eventually use genome sequencing at diagnosis. Alternatively, cells characteristically exhibit activation of PI3K/mTOR and MEK- screening and targeted approaches may be used, including low- ERK signaling that is sensitive to PI3K inhibitors (but not MEK density gene expression arrays to identify Ph-like cases, RT-PCR to inhibitors), suggesting that this may represent a therapeutic ap- detect known fusions, FISH for kinase disruption and speciﬁc proach in this form of ALL. T-lineage ALL As in B-progenitor ALL, T-lineage ALL is characterized by a CRLF2-rearranged ALL generally stable genome and subtypes deﬁned by constellations of CRLF2 rearrangements are common in Ph-like ALL, but are also structural and sequence alterations that deregulate key cellular observed in non-Ph-like ALL, particularly in 50% of Down pathways. These include recurring translocations that deregulate syndrome ALL, in which IKZF1 mutations are less frequent. Sequence mutations and deletions involve genes that to the IGH locus (IGH-CRLF2) or by a focal deletion 5 of CRLF2 regulate T-cell development and tumor suppressor pathways, includ- resulting in a P2RY8-CRLF2 fusion. Approximately half of CRLF2-rearranged cases have concomitant activating sequence mutations of JAK1/2, most Recent studies have characterized ETP ALL, an immature neoplasm commonly at JAK2 p. Arg683 and many of the CRLF2-rearranged that lacks expression of several T-cell markers (CD1a, CD8, and cases lacking Janus kinase mutations have other lesions that also weak/absent CD5) and exhibits aberrant expression of myeloid/stem activate JAK-STAT signaling, including IL7R mutations and dele- cell markers. CRLF2- poor outcome, although this is less striking in recent studies. This is particularly relevant given the growing interest in EP300); Ras and cytokine receptor signaling (NRAS, IL7R, KRAS, the use of deep-sequencing approaches to monitor levels of minimal JAK1/3, NF1, PTPN11, SH2B3), and chromatin-modifying genes, residual disease. The transcriptional Germline genetic variation and ALL risk proﬁle of ETP ALL is most similar to normal hematopoietic rather There has been historically limited evidence of a major role of than normal T-cell precursors, suggesting that ETP ALL may inherited predisposition to developing ALL, with limited familial represent part of spectrum of primitive neoplasms that arise in clustering and twin concordance explained by intrauterine transmis- progenitors that retain multilineage potential, including “near” ETP sion of leukemic clones. However, recent studies have implicated ALL (with normal CD5 expression) and possibly biphenotypic and several common inherited variants and rare mutations in ALL bilineal ALL. The degree of similarity of the genetic basis of these susceptibility. Genome-wide association studies using microarrays entities to ETP ALL is currently unknown. The involvement of to genotype millions of single nucleotide polymorphisms in ALL JAK-STAT and PRC2 pathways in ETP ALL suggests that JAK cases and ethnically matched controls have identiﬁed multiple inhibition and/or chromatin-modifying agents may be therapeuti- susceptibility loci associated with ALL risk. The most reproducible cally useful in ETP ALL and both have shown activity in preclinical associations have been in genes that are also targets of somatic models. In addition, proteins and CNOT3, which encodes part of a transcriptional 6 speciﬁc variants are associated with ALL risk and outcome in regulatory complex. Transcriptome sequencing of T-ALL has speciﬁc ethnic groups (ARID5B) and with speciﬁc subtypes of ALL identiﬁed novel mutations and chimeric fusions, including kinases 39 (GATA3 and Ph-like ALL). Inherited TP53 mutations are a hallmark of low hypodiploid ALL. In addition, that study identiﬁed additional cases with germline Genetic heterogeneity, clonal evolution, and relapse mutations in Ras signaling and DNA repair that are likely to be in ALL pathogenic in ALL.
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