Anticoagulation in chronic kidney disease: current status and future perspectives

Chronic kidney disease (CKD) is being diagnosed increasingly worldwide. It is often identified in individuals with comorbidities, which may increase the already heightened risk of thrombosis and hemorrhage associated with CKD. Oral anticoagulation is an effective means of reducing rates of ischemic stroke and systemic embolism in patients with atrial fibrillation and minimizes the morbidity and mortality caused by venous thromboembolic disease. Despite the proven benefits in the majority of patients, these have not been so clearly realized in patients with CKD due to the precarious balance between bleeding and thromboembolic complications. In this review, the current status of anticoagulant utilization in CKD is examined, and some practical recommendations are put forward to assist in the decision-making process of safely anticoagulating patients with CKD diagnosed with atrial fibrillation and venous thromboembolism.

The prothrombotic tendency of metabolic-associated fatty liver disease

Our understanding of the function of the liver has evolved over the centuries. Early theories proposing that the liver could be used to divine the future have been superseded by our current knowledge of the importance of the liver in processes such as digestion and detoxification. Similarly, although liver disease was previously associated with only an increased risk of bleeding, there is now a substantial body of evidence demonstrating an increased thrombotic potential in patients with this disease. Metabolic-associated fatty liver disease (MAFLD) is increasing in frequency and is likely to overtake alcoholic liver disease as the primary indication for liver transplant in the future. In this review, we discuss the evidence linking liver disease, and MAFLD in particular, with arterial and venous thromboembolic disease. We review the safety and efficacy of anticoagulation in advanced liver disease and consider whether antithrombotic agents could slow or halt the progression of fibrosis in MAFLD.

Venous thromboembolism in multiple myeloma: Increasing evidence in support of direct oral anticoagulants

Venous thromboembolism (VTE) continues to cause significant morbidity and excess mortality in patients with multiple myeloma. The report by Costa and colleagues demonstrates superiority of direct oral anticoagulants over aspirin in terms of VTE prevention, without increased bleeding complications seen. Commentary on: Costa et al. Direct oral anticoagulants versus aspirin for primary thromboprophylaxis in patients with multiple myeloma undergoing outpatient therapy: A systematic review and updated meta-analysis. Br J Haematol 2023;203:395-403.

Sialofucosylation Enables Platelet Binding to Myeloma Cells via P-Selectin and Suppresses NK Cell-Mediated Cytotoxicity

Multiple myeloma (MM) is a plasma cell disorder that develops in the bone marrow (BM) and is characterized by uncontrolled proliferation and the ability to disseminate to different sites of the skeleton. Sialofucosylated structures, particularly Sialyl Lewis a/x (SLe^a/x), facilitate the homing of MM cells into the BM, leading to resistance to bortezomib in vivo. Platelets have been shown to play an important role in tumor metastasis. Platelets can bind to the surface of cancer cells, forming a "cloak" that protects them from the shear stress of the bloodstream and natural killer (NK) cell-mediated cytotoxicity. In this study, we showed that the presence of SLe^a/x induced a strong binding of MM cells to P-selectin, leading to specific and direct interactions with platelets, which could be inhibited by a P-selectin-blocking antibody. Importantly, platelets surrounded SLe^a/x-enriched MM cells, protecting them from NK cell-mediated cytotoxicity. The interactions between the platelets and MM cells were also detected in BM samples obtained from MM patients. Platelet binding to SLe^a/x-enriched MM cells was increased in patients with symptomatic disease and at relapse. These data suggest an important role of SLe^a/x and platelets in MM disease progression and resistance to therapy.

Bispecific Antibodies in Multiple Myeloma: Opportunities to Enhance Efficacy and Improve Safety

Multiple myeloma (MM) is the second most common haematological neoplasm of adults in the Western world. Overall survival has doubled since the advent of proteosome inhibitors (PIs), immunomodulatory agents (IMiDs), and monoclonal antibodies. However, patients with adverse cytogenetics or high-risk disease as determined by the Revised International Staging System (R-ISS) continue to have poorer outcomes, and triple-refractory patients have a median survival of less than 1 year. Bispecific antibodies (BsAbs) commonly bind to a tumour epitope along with CD3 on T-cells, leading to T-cell activation and tumour cell killing. These treatments show great promise in MM patients, with the first agent, teclistamab, receiving regulatory approval in 2022. Their potential utility is hampered by the immunosuppressive tumour microenvironment (TME), a hallmark of MM, which may limit efficacy, and by undesirable adverse events, including cytokine release syndrome (CRS) and infections, some of which may be fatal. In this review, we first consider the means of enhancing the efficacy of BsAbs in MM. These include combining BsAbs with other drugs that ameliorate the effect of the immunosuppressive TME, improving target availability, the use of BsAbs directed against multiple target antigens, and the optimal time in the treatment pathway to employ BsAbs. We then discuss methods to improve safety, focusing on reducing infection rates associated with treatment-induced hypogammaglobulinaemia, and decreasing the frequency and severity of CRS. BsAbs offer a highly-active therapeutic option in MM. Improving the efficacy and safety profiles of these agents may enable more patients to benefit from these novel therapies and improve outcomes for patients with high-risk disease.

Challenges in managing patients on anticoagulation: Thrombocytopenia, resumption after bleeding and recurrent thrombosis

Prescribing of anticoagulation is increasing worldwide. This is partly reflective of an aging population with cardiovascular comorbidities such as arrhythmias and prosthetic heart valves, alongside improvements in cancer treatments and survival. In this review, we discuss three common challenges faced by clinicians. These concern the management of patients with thrombosis and thrombocytopenia, resumption of anticoagulation in patients with a history of gastrointestinal or intracranial haemorrhage, and how to approach and treat a patient with recurrent thrombosis on anticoagulation. We consider the available evidence including relevant published recommendations and propose practical management suggestions to aid clinicians faced with these dilemmas.

Practical management of the haemorrhagic complications of myeloproliferative neoplasms

Myeloproliferative neoplasms can be associated with bleeding manifestations which can cause significant morbidities. Although haematologists are aware of the likelihood of this complication in the setting of myeloproliferative neoplasms, it may often be overlooked especially in patients with no extreme elevation of blood counts and those with myelofibrosis. Acquired von Willebrand syndrome and platelet dysfunction are the two common diagnoses to be considered in this regard. In this review article, we discuss the mechanisms for the development of these rare bleeding disorders, their diagnosis and practical management.

CyBorD-DARA in Newly Diagnosed Transplant-Eligible Multiple Myeloma: Results from the 16-BCNI-001/CTRIAL-IE 16-02 Study Show High Rates of MRD Negativity at End of Treatment

The phase 1b 16-BCNI-001/CTRIAL-IE 16-02 CyBorD-DARA trial investigated the combination of Daratumumab with cyclophosphamide, bortezomib and dexamethasone in patients with newly diagnosed multiple myeloma (NDMM), followed by autologous stem cell transplantation and Daratumumab maintenance. CR/sCR rates were 50% after transplant and 62.5% at end of treatment. The overall percentage of patients achieving complete response or better was 77.8%. Progression-free survival rate at end of maintenance was 81.3% and estimated 2-year overall survival was 88.9%. 37.5% of patients demonstrated sustained MRD negativity to a level of 10^-5 from transplant to analysis at EOT. In this phase 1b study, we have shown CyBorD-DARA to be an effective and well-tolerated immunomodulatory agent-free regiment in transplant-eligible NDMM.

Non‐factor therapies for bleeding disorders: A primer for the general haematologist

Management of patients with severe bleeding disorders, particularly haemophilia A and B, and to a lesser extent, von Willebrand disease, has come on leaps and bounds over the past decade. Until recently, patients relied upon the administration of factor concentrates to prevent or treat bleeding episodes. Factor administration requires intravenous access and, in up to one‐third of patients, leads to the development of neutralising antibodies, or inhibitors, which are associated with more frequent bleeding episodes and higher morbidity. Novel non‐factor therapies may offer a solution to these unmet needs. In this review, we discuss the factor mimetics, particularly emicizumab, and the rebalancing agents, which inhibit antithrombin, tissue factor pathway inhibitor and activated protein C, and novel treatments to enhance von Willebrand factor levels. We review the available trial data, unanswered questions and challenges associated with these new treatment modalities. Finally, we provide practical management algorithms to aid the general haematologist when faced with a patient receiving emicizumab who requires surgery or may develop bleeding.

Trends in autologous stem cell transplantation for newly diagnosed multiple myeloma: Changing demographics and outcomes in European Society for Blood and Marrow Transplantation centres from 1995 to 2019

Multiple myeloma (MM) accounts for 10% of haematological malignancies. Overall survival (OS) has improved in recent years due to increased use of autologous stem cell transplantation (ASCT) in the treatment of newly diagnosed MM and the advent of novel agents, including proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies. To assess trends in ASCT including patient selection, choice of induction regimen, depth of response and survival, we performed a retrospective analysis of all patients undergoing first ASCT for MM in European Society for Blood and Marrow Transplantation centres between 1995 and 2019. A total of 117 711 patients across 575 centres were included. The number of transplants performed increased sevenfold across the study period. The median age increased from 55 to 61 years, and the percentage of patients aged >65 years rose from 7% to 30%. Use of chemotherapy-based induction fell significantly, being largely replaced by bortezomib-based regimens. The two-year complete response rate increased from 22% to 42%. The five-year progression-free survival and OS rates increased from 28% to 31% and from 52% to 69%, respectively. Transplant mortality fell from 5.9% to 1.5%. Ongoing advances in MM treatment may challenge the future role of ASCT. However, at the current time, ASCT remains central to the MM treatment paradigm.

Vaccine-induced thrombosis and thrombocytopenia (VITT) in Ireland: A review of cases and current practices

Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) virus pandemic, several highly effective and safe vaccines have been produced at remarkable speed. Following global implementation of vaccination programmes, cases of thrombosis with thrombocytopenia following administration of adenoviral vector-based vaccines started being reported. In this review we discuss the known pathogenesis and epidemiology of so-called vaccine induced thrombocytopenia and thrombosis (VITT). We consider the available guidelines, diagnostic laboratory tests and management options for these patients. Finally, we discuss important unanswered questions and areas for future research in this novel pathoclinical entity.

Port removal in patients receiving emicizumab prophylaxis: A single centre experience and review of the literature

INTRODUCTION

Treatment of patients with Haemophilia A has improved significantly in recent years since the advent of novel therapeutic agents such as emicizumab. The low annualised bleeding rates associated with emicizumab have liberated many patients from the need for central venous access devices (CVAD). Optimal peri-operative management of CVAD removal is not currently known and there are no specific formal recommendations available.

AIM

We reviewed outcomes in a paediatric cohort in our centre undergoing CVAD removal without pre-operative factor or bypassing agent and reviewed the literature regarding port removal in patients on Emicizumab.

METHODS

Ten male patients with severe Haemophilia A underwent CVAD removal without planned administration of factor concentrate or bypassing agent. Patients were monitored in hospital for 24 h with routine laboratory testing pre- and post-operatively.

RESULTS

No significant bleeding episodes occurred in any patient, no patient required factor concentrate or bypassing agent and no patients were readmitted due to bleeding within 7 days of surgery.

CONCLUSION

We propose that, in the era of emicizumab, prophylactic factor administration pre-operatively for elective CVAD removal is not required in the majority of cases.

Heparin - Messias or Verschlimmbesserung?

A heightened risk of thrombosis noted early on with the severe acute respiratory syndrome coronavirus 2 infection led to the widespread use of heparin anticoagulation in the coronavirus disease 2019 (COVID-19) pandemic. However, reports soon started appearing in the literature where an apparent failure of heparin to prevent thrombotic events was observed in hospitalized patients with this viral infection. In this review, we explore the likely mechanisms for heparin failure with particular relevance to COVID-19. We also explore the role of anti-Xa assays and global hemostatic tests in this context. The current controversy of dosing heparin in this disease is detailed with some possible mechanistic reasons for anticoagulant failure. We hope that lessons learnt from the use of heparin in COVID-19 could assist us in the appropriate use of this anticoagulant in the future.

The evolving status of immunotherapies in multiple myeloma: the future role of bispecific antibodies

Treatment outcomes in multiple myeloma (MM) have improved dramatically over the past 10 years. However, patients with high-risk disease such as those with Stage III disease by the Revised International Staging System, the presence of adverse cytogenetics, or who are refractory to proteosome inhibitors, immunomodulatory drugs and monoclonal antibodies may have dismal outcomes. These patients represent an urgent ongoing need in MM. One of the hallmarks of MM is immune dysfunction and a tumour-permissive immune microenvironment. Ameliorating the immune-paresis could lead to improved outcomes. The role of immunotherapies has been growing at an exponential pace with numerous agents under development in clinical trials. In the present review, we provide an overview of immunotherapies in MM, focussing on bispecific antibodies (BsAbs). We review efficacy outcomes from the published clinical trials and consider the important safety aspects of these therapies, in particular the risk of cytokine-release syndrome and immune effector cell-associated neurotoxicity syndrome, and how these compare with patients receiving chimeric antigen receptor T cells. We discuss the MM epitopes being targeted by BsAbs, either in clinical or preclinical stages, and we consider where these therapies might best fit within the future ever-changing paradigm of MM treatment.

Thromboprophylaxis in COVID-19 - Rationale and considerations

The Corona Virus Disease-2019 (COVID-19) pandemic is associated with a very high incidence of thrombotic complications. The exact mechanisms for this excess risk for clots have not been elucidated although one of the often-quoted pathophysiological entity is immunothrombosis. Recognition of thrombotic complications early on in this pandemic led to an over-explosion of studies which looked at the benefits of anticoagulation to mitigate this risk. In this review, we examine the rationale for thromboprophylaxis in COVID-19 with particular reference to dosing and discuss what may guide the decision-making process to consider anticoagulation. In addition, we explore the rationale for thrombosis prevention measures in special populations including outpatient setting, pregnant females, children, those with high body mass index and those on extracorporeal membrane oxygenation.

Thrombosis in immune thrombocytopenia - current status and future perspectives

Immune thrombocytopenia (ITP) is an autoimmune disorder in which a combination of defective platelet production and enhanced clearance leads to thrombocytopenia. The primary aim for therapy in patients with this condition is the prevention of bleeding. However, more recently, increased rates of venous and arterial thrombotic events have been reported in ITP, even in the context of marked thrombocytopenia. In this review we discuss the epidemiology, aetiology and management of thrombotic events in these patients. We consider the impact of ITP therapies on the increased thrombotic risk, in particular the use of thrombopoietin-receptor agonists (TPO-RAs), as well as factors inherent to ITP itself. We also discuss the limited evidence available to guide clinicians in the treatment of these complex cases.

Cyclophosphamide alters the tumor cell secretome to potentiate the anti-myeloma activity of daratumumab through augmentation of macrophage-mediated antibody dependent cellular phagocytosis

Multiple Myeloma (MM) is a malignant disorder of plasma cells which, despite significant advances in treatment, remains incurable. Daratumumab, the first CD38 directed monoclonal antibody, has shown promising activity alone and in combination with other agents for MM treatment. Daratumumab is thought to have pleiotropic mechanisms of activity including natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (ADCC). With the knowledge that CD38-expressing NK cells are depleted by daratumumab, we sought to investigate a potential mechanism of enhancing macrophage-mediated antibody-dependent cellular phagocytosis (ADCP) by combining daratumumab with cyclophosphamide (CTX). Cyclophosphamide’s immunomodulatory function was investigated by conditioning macrophages with tumor cell secretome collected from cyclophosphamide treated MM cell lines (CTX-TCS). Flow cytometry analysis revealed that CTX-TCS conditioning augmented the migratory capacity of macrophages and increased CD32 and CD64 Fcγ receptor expression on their cell surface. Daratumumab-specific tumor clearance was increased by conditioning macrophages with CTX-TCS in a dose-dependent manner. This effect was impeded by pre-incubating macrophages with Cytochalasin D (CytoD), an inhibitor of actin polymerization, indicating macrophage-mediated ADCP as the mechanism of clearance. CD64 expression on macrophages directly correlated with MM cell clearance and was essential to the observed synergy between cyclophosphamide and daratumumab, as tumor clearance was attenuated in the presence of a FcγRI/CD64 blocking agent.

Cyclophosphamide independently enhances daratumumab-mediated killing of MM cells by altering the tumor microenvironment to promote macrophage recruitment, polarization to a pro-inflammatory phenotype, and directing ADCP. These findings support the addition of cyclophosphamide to existing or novel monoclonal antibody-containing MM regimens.

Current and emerging immunotherapeutic approaches to the treatment of multiple myeloma

Multiple myeloma (MM) has a worldwide incidence of 1-5/100,000/year. Outcomes have improved significantly in recent years following incorporation of immunomodulatory drugs and proteasome inhibitors into standard-of-care regimes. MM is profoundly immunosuppressive, enabling immune evasion, proliferation and disease progression. The role of the immune system in MM is becoming increasingly characterized and understood, and numerous therapies are under development or in routine clinical use targeting these elements of MM pathogenesis. In this review we discuss the immunosuppressive effects of MM, then the therapies targeting these defects. Specifically, we review the monoclonal and bispecific antibodies, alongside adoptive cellular therapies currently under investigation.

The problem of under-diagnosis and over-diagnosis of pulmonary embolism

Pulmonary embolism (PE) is an increasingly recognised condition which is associated with significant morbidity and mortality. Despite the better awareness of this serious condition, the diagnosis is still overlooked in many cases with sometimes fatal consequences. Under-diagnosis may be due to several reasons including reliance on non-specific 'classic' symptoms, belief that bedside measurements will likely be abnormal in the setting of acute PE, and confounding factors like co-existent cardiorespiratory diseases or being in an intensive care unit, where the diagnosis may not be considered. At the same time, incidental diagnosis of PE is occurring more often due to frequent use of imaging investigations alongside advancements in CT technology, and dilemma exists as to whether the chance finding of PE requires anticoagulation, especially when identified only at the subsegmental level. This article reviews these two issues of under-diagnosis and over-diagnosis of PE in the current era.

Reintroduction of anticoagulant therapy after intracranial haemorrhage: If and when?

Intracranial haemorrhage is a devastating complication of anticoagulation. In surviving patients, physicians will be faced with the dilemma of if and when treatment should be reintroduced. There is little evidence to support this decision making and guidelines refrain from making specific recommendations. Existing data relates almost exclusively to vitamin K antagonists and is entirely retrospective. There appears to be an overall benefit to reintroducing anticoagulation in most patients; although, this may not be advocated in those at the highest risk of recurrent bleeding. The issue of when to reintroduce treatment is more controversial. The literature suggests timing could be anywhere between 7days and 30weeks; however there is no overall consensus. This review summarises what evidence is currently available to support decision making and suggests pragmatic management options based on a risk-benefit assessment of thromboembolism and recurrent bleeding; however, it should be acknowledged this may not be entirely evidence-based.

Development and implementation of a 'Mental Health Finder' software tool within an electronic medical record system

BACKGROUND

In Ireland, as in many other healthcare systems, mental health service provision is being reconfigured with a move toward more care in the community, and particularly primary care. Recording and surveillance systems for mental health information and activities in primary care are needed for service planning and quality improvement.

AIMS

We describe the development and initial implementation of a software tool ('mental health finder') within a widely used primary care electronic medical record system (EMR) in Ireland to enable large-scale data collection on the epidemiology and management of mental health and substance use problems among patients attending general practice.

METHODS

In collaboration with the Irish Primary Care Research Network (IPCRN), we developed the 'Mental Health Finder' as a software plug-in to a commonly used primary care EMR system to facilitate data collection on mental health diagnoses and pharmacological treatments among patients. The finder searches for and identifies patients based on diagnostic coding and/or prescribed medicines. It was initially implemented among a convenience sample of six GP practices.

RESULTS

Prevalence of mental health and substance use problems across the six practices, as identified by the finder, was 9.4% (range 6.9-12.7%). 61.9% of identified patients were female; 25.8% were private patients. One-third (33.4%) of identified patients were prescribed more than one class of psychotropic medication. Of the patients identified by the finder, 89.9% were identifiable via prescribing data, 23.7% via diagnostic coding.

CONCLUSIONS

The finder is a feasible and promising methodology for large-scale data collection on mental health problems in primary care.

Outcome of necrosectomy in acute pancreatitis: the case for continued vigilance

BACKGROUND

Surgery for pancreatic necrosis complicating acute severe pancreatitis carries a high risk of mortality and may be influenced by a range of variables including patterns of referral, case selection and quality of care.

METHODS

An observational study of a consecutive series of 54 patients undergoing pancreatic necrosectomy in a specialist Hepatobiliary unit over an 8-year study period. Principal outcomes were organ dysfunction and physiological derangement in relation to surgery, microbial colonization of necrosis and relation to outcome, re-operation rates, requirement for peri-operative nutritional support, trends in mortality and survival analysis.

RESULTS

Necrosectomy was associated with statistically significant deterioration in immediate postoperative organ dysfunction scores (ANOVA P < 0.01). Infected necrosis was present in 36 (68%). Fungal colonization of necrosis was present in 5 (9%). Mortality in this subgroup was 80% (4 deaths). There was no association between bacterial colonization of necrosis and death in this study (P = 0.77; Fisher exact test; relative risk 0.9,95% confidence interval 0.54-1.54). Twenty patients (37%) required further surgical intervention with an average of 1.5 surgical procedures per patient. Twenty-three patients (43%) died. Patient survival to discharge was best predicted by admission APACHE-II score with relative risk of death increasing 14% for each unit increase in APACHE-II score at admission.

CONCLUSIONS

The results of the present study illustrate that there is no place for complacency in the surgical management of patients with severe acute pancreatitis. A clinical governance approach would promote pre-defined protocols between admitting hospitals and tertiary referral centres. Future research should target new interventions in patients with high admission APACHE-II scores in whom prognosis is particularly poor and explore the role of infection of necrotic tissue.

Induction of the mammalian node requires Arkadia function in the extraembryonic lineages

The early mammalian embryo is patterned by signals emanating from extraembryonic and embryonic signalling centres, most notably the anterior visceral endoderm (AVE) and the node, respectively. The AVE is responsible for anterior development, whereas further axis specification depends on the node, the equivalent of Spemann's organizer. Formation of the node, at the anterior primitive streak, depends on expression of the transcription factor HNF3beta (ref. 4). However, both the source and the nature of the signals responsible for inducing the node have been unknown. Here we describe a recessive lethal mutation, arkadia, generated using gene-trap mutagenesis. Mutant embryos establish an AVE but fail to maintain anterior embryonic structures and lack a node. The mutation has disrupted the Arkadia gene, which encodes a putative intracellular protein containing a RING domain. Arkadia is essential for HNF3beta expression in the anterior primitive streak. Analysis with chimaeras, however, shows that Arkadia functions within extraembryonic tissues, revealing that these are required to induce the node. Furthermore, our experiments show that Arkadia interacts genetically with the transforming growth factor (TGF)beta-like factor Nodal, implying that Nodal mediates the function of Arkadia in node induction.

Transient transfection of Theileria annulata

We have developed a method to transiently transfect infective, uninucleate, Theileria annulata sporozoites. Transfection vectors have been constructed using a number of T. annulata 5' gene flanking sequences linked to the enhanced green fluorescence protein (eGFP) reporter gene. Sporozoites were transfected with these constructs using the lipid transfection agent SuperFect, then allowed to infect purified bovine mononuclear cells (PBMs). Green fluorescence was observed in developing trophozoites, 36-40 h post infection, using constructs containing the upstream regions of the T. annulata Hsp70, T. annulata merozite surface antigen 1 (TamS1) and T. annulata macroschizont-specific AT hook-containing protein2 (TashAT2) genes. A construct with the 5' TamS1 upstream sequence in reverse orientation gave no detectable fluorescence indicating fluorescence was derived by expression from the T. annulata promoter. A cytomegalovirus (CMV) promoter construct showed no activity in this stage of the parasite. However, when this construct was introduced directly into schizont-infected cells by electroporation, fluorescence was observed in the bovine cells but not the schizont. We describe the significance of these results in relation to novel control strategies and the fundamental biology of Theileria parasites.

A decrease in remodeling accounts for the accumulation of arachidonic acid in murine mast cells undergoing apoptosis

The goal of this study was to examine arachidonic acid (AA) metabolism by murine bone marrow-derived mast cells (BMMC) during apoptosis induced by cytokine depletion. BMMC deprived of cytokines for 12-48 h displayed apoptotic characteristics. During apoptosis, levels of AA, but not other unsaturated fatty acids, correlated with the percentage of apoptotic cells. A decrease in both cytosolic phospholipase A(2) expression and activity indicated that cytosolic phospholipase A(2) did not account for AA mobilization during apoptosis. Free AA accumulation is also unlikely to be due to decreases in 5-lipoxygenase and/or cyclooxygenase activities, since BMMC undergoing apoptosis produced similar amounts of leukotriene B(4) and significantly greater amounts of PGD(2) than control cells. Arachidonoyl-CoA synthetase and CoA-dependent transferase activities responsible for incorporating AA into phospholipids were not altered during apoptosis. However, there was an increase in arachidonate in phosphatidylcholine (PC) and neutral lipids concomitant with a 40.7 +/- 8.1% decrease in arachidonate content in phosphatidylethanolamine (PE), suggesting a diminished capacity of mast cells to remodel arachidonate from PC to PE pools. Further evidence of a decrease in AA remodeling was shown by a significant decrease in microsomal CoA-independent transacylase activity. Levels of lyso-PC and lyso-PE were not altered in cells undergoing apoptosis, suggesting that the accumulation of lysophospholipids did not account for the decrease in CoA-independent transacylase activity or the induction of apoptosis. Together, these data suggest that the mole quantities of free AA closely correlated with apoptosis and that the accumulation of AA in BMMC during apoptosis was mediated by a decreased capacity of these cells to remodel AA from PC to PE.

Treatment of canine leproid granuloma syndrome: preliminary findings in seven dogs

OBJECTIVE

To determine effective treatment strategies for patients with refractory canine leproid granuloma syndrome.

DESIGN

Multi-institutional retrospective/prospective case series using client-owned dogs.

PROCEDURE

Seven dogs (four Boxers, one Dobermann, one Bullmastiff and one Bullmastiff cross-bred; ages 3 to 11 years) with leproid granulomas were treated successfully using a variety of treatment regimens. These cases were recruited because: lesions were either widely distributed over the dog; progressive, despite routine therapy, or were associated with particularly disfiguring lesions. The treatment regimen evolved during the course of the clinical study.

RESULTS

Combination therapy using rifampicin (5 to 15 mg/kg p.o., every 24 h) and clarithromycin (8 to 24 mg/kg p.o. daily; dose divided every 8 or every 12 h) was used most frequently and proved to be effective and free from side effects. Total daily doses of clarithromycin in excess of 14 mg/kg were considered optimal and long treatment courses, in the order of 1 to 3 months, were used. Combination therapy using rifampicin (25 mg/kg; that is, higher than the recommended dose) and clofazimine was effective in one case, but resulted in hepatotoxicity. A topical formulation of clofazimine in petroleum jelly was used as an adjunct to oral rifampicin and doxycycline in another patient treated successfully.

CONCLUSION

Based on our evolving clinical experience, a combination of rifampicin (10 to 15 mg/kg p.o., every 24 h) and clarithromycin (15 to 25 mg/kg p.o. total daily dose; given divided every 8 to 12 h) is currently recommended for treating severe or refractory cases of canine leproid granuloma syndrome. Treatment should be continued (typically for 4 to 8 weeks) until lesions are substantially reduced in size and ideally until lesions have resolved completely. A topical formulation, containing clofazimine in petroleum jelly may be used as an adjunct to systemic drug therapy. Further work is required to determine the most cost effective treatment regimen for this condition.

An upstream element of the TamS1 gene is a site of DNA-protein interactions during differentiation to the merozoite in Theileria annulata

Apicomplexan parasites are major pathogens of humans and domesticated animals. A fundamental aspect of apicomplexan biology, which may provide novel molecular targets for parasite control, is the regulation of stage differentiation. Studies carried out on Theileria annulata, a bovine apicomplexan parasite, have provided evidence that a stochastic process controls differentiation from the macroschizont to the merozoite stage. It was postulated that this process involves the presence of regulators of merozoite gene expression in the preceding stage of the life cycle, and that during differentiation a quantitative increase of these factors occurs. This study was carried out to test these postulations. Nuclear run-on analysis showed that TamS1 expression is controlled, at least in part, at the transcriptional level. The transcription start site showed homology with the consensus eukaryotic initiator motif, and study of the 5′ upstream region by the electrophoretic mobility-shift assay demonstrated that a 23 bp motif specifically bound factors from parasite-enriched nuclear extracts. Three complexes were shown to bind to a 9 bp core binding site (5′-TTTGTAGGG-3′). Two of these complexes were present in macroschizont extracts but were found at elevated levels during differentiation. Both complexes contain a polypeptide of the same molecular mass and may be related via the formation of homodimer or heterodimer complexes. The third complex appears to be distinct and was detected at time points associated with the transition to high level merozoite gene expression.

Evaluation of soy phytoestrogens for the treatment of hot flashes in breast cancer survivors: A North Central Cancer Treatment Group Trial

PURPOSE

Hot flashes represent a significant clinical problem for some breast cancer survivors. Safe, effective treatment is needed for this prominent clinical problem. Although it has been shown that estrogen or progesterone replacement therapy can alleviate this problem, there are continued safety concerns regarding the use of hormonal therapies in these women. Based on anecdotal information, we hypothesized that soy-derived phytoestrogens, weak estrogen-like substances in the soybean that demonstrate estrogen agonist and/or antagonist effects when they bind to estrogen receptors, could alleviate hot flashes. This current trial was designed to investigate this hypothesis.

PATIENTS AND METHODS

This double-blind clinical trial involved breast cancer survivors with substantial hot flashes. After randomization, patients underwent a 1-week baseline period with no therapy. This was followed by 4 weeks of either soy tablets or placebo. The patients then crossed over to the opposite arm in a double-blind manner for the last 4 weeks. Patients completed a daily questionnaire documenting hot flash frequency, intensity, and perceived side effects.

RESULTS

Of the 177 women who were randomized and started the study substance, 155 (88%) provided useable data over the first 5 weeks; 149 provided usable data over the entire 9 weeks. There was no suggestion that the soy product was more effective in reducing hot flashes than the placebo. At study completion, patients preferred the soy product 33% of the time, the placebo 37% of the time, and neither substance 31% of the time. No toxicity was observed.

CONCLUSION

The soy product did not alleviate hot flashes in breast cancer survivors.

Correlates of simulated hill climb cycling performance

The aim of this study was to assess the relationship between several commonly used aerobic and anaerobic cycle ergometer tests and performance during a treadmill cycling hill climb. Eight competitive cyclists (age 27+/-7 years; body mass 73.2+/-5.2 kg; height 177+/-6 cm; mean +/- s) completed six tests in random order: a lactate minimum test; a Wingate anaerobic power test; and two 6-km climbs at 6% and two 1-km climbs at 12% gradient performed on a motorized treadmill. The mean times and power outputs for the 6-km and 1-km climbs were 16:30+/-1:08 min: s and 330+/-17.8 W, and 4:19+/-0:27 min: s and 411+/-24.4 W, respectively. The best individual predictor of 6-km and 1-km performance times was the time for the corresponding climb at the other distance (r = 0.97). The next strongest predictor of both hill climb performances was the average power produced during the Wingate test divided by body mass. Stepwise regression analysis showed that the two variables contributing most to the prediction equation for both climbs were the Wingate average power per unit of body mass and maximal aerobic power divided by total mass (rider + bike), which together accounted for 92 and 96% of the variability in the 6-km and 1-km climbs. In conclusion, among competitive cyclists, the Wingate average power per unit of body mass was the best single predictor of simulated cycling hill climb performance at the distance and gradient used.

Phase III controlled evaluation of glutamine for decreasing stomatitis in patients receiving fluorouracil (5-FU)-based chemotherapy

Mucositis is a prominent dose-limiting toxicity associated with 5-FU-based chemotherapy. On the basis of preliminary data suggesting that the amino acid glutamine could alleviate this problem, the authors developed this trial. Patients scheduled to receive their first 5-FU-based chemotherapy regimen were selected for study. Following stratification, patients were randomized, in a double-blind manner, to receive oral glutamine or a placebo preparation in a prophylactic manner. Patients in both groups were given oral cryotherapy before chemotherapy and were evaluated for mucositis by standard physicians' evaluation and by a self-report instrument. Sixty-six patients were randomized to receive glutamine and 68 to receive the placebo preparation. There were no significant differences or substantial trends in the mucositis scores between the two study arms as measured by either the physicians or the patients. It was concluded that the dose and schedule of glutamine used in this clinical trial does not alleviate 5-FU-induced mucositis.

Directing differentiation in Theileria annulata: old methods and new possibilities for control of apicomplexan parasites

Apicomplexan parasites are major pathogens of humans and domesticated animals. The ability of these organisms to evade the host immune response and the emergence of drug-resistant parasites indicates a need for the identification of novel control strategies. Ideally, selected targets should be shared by a range of apicomplexans and fundamental to parasite biology. One process of apicomplexan biology which may provide this type of target is the molecular regulation of stage differentiation. This paper has reviewed studies carried out on differentiation of Theileria annulata and has highlighted general similarities with other apicomplexan differentiation steps. Similarities include asynchrony of differentiation, the loss (attenuation) of differentiation potential and an association between reduced proliferation and differentiation. In addition, novel data are presented assessing a possible role for a signal transduction mechanism or a direct involvement of classical heat-shock polypeptides in regulating differentiation of T. annulata in vitro. These studies, and previously published data, have led to the postulation that progression to the next stage of the life-cycle can be predetermined and involves the attainment of a quantitative threshold by regulators of gene expression. A modification of this model takes into account that for certain in-vitro systems, or differentiation steps in vivo, the process has to be initiated by alteration of the extracellular environment. Work which has shown that the time taken to achieve differentiation can be increased or decreased is also outlined. The ability to change the timing of differentiation suggests that the associated regulatory mechanism could be manipulated directly to significantly influence the outcome of an apicomplexan infection. The observation that a number of existing drugs and control strategies may exert their protective effect by altering differentiation potential supports this possibility.

Phonological awareness deficits in developmental dyslexia and the phonological representations hypothesis

The claim that the well-documented difficulties shown by dyslexic children in phonological awareness tasks may arise from deficits in the accuracy and the segmental organization of the phonological representations of words in their mental lexicons is receiving increasing interest from researchers. In this experiment, two versions of the phonological representations hypothesis were investigated by using a picture naming task and a battery of phonological measures at three linguistic levels (syllable, onset-rime, phoneme). The picture naming task was used to identify words for which dyslexic and control children had accurate vs inaccurate phonological representations, and performance in the phonological awareness tasks was then compared for the words which had precise vs imprecise representations. Findings indicated that frequency effects in the phonological awareness tasks at all levels disappeared for dyslexic and control children once representational quality was taken into account, and that the availability of sublexical units for analysis appeared to differ according to (1) the accuracy and retrieval of the phonological representation and (2) the linguistic level tapped by the phonological awareness task.

Picture naming deficits in developmental dyslexia: the phonological representations hypothesis

The picture and word naming performance of developmental dyslexics was compared to the picture and word naming performance of non-dyslexic ("garden variety") poor readers, reading age, and chronological age-matched controls. The stimulus list used for both tasks was systematically manipulated for word length and word frequency. In order to examine picture naming errors in more depth, an object name recognition test assessed each subject's vocabulary knowledge of those names which they were unable to spontaneously label in the picture naming task. Findings indicated that the dyslexic and the garden variety poor readers exhibited a picture naming deficit relative to both chronological and reading age-matched controls. Findings also indicated that both groups of impaired readers obtained superior scores in the word naming task than in the picture naming task, while both groups of controls showed no difference in performance across tasks. The dyslexics' picture naming errors, but not those of the garden variety poor readers, were particularly marked on polysyllabic and/or low frequency words, indicating a possible phonological basis to the picture naming deficit of the dyslexic children. These children also recognized significantly more unnamed target words than all comparison groups, suggesting a particular difficulty in retrieving the phonological codes of known picture names rather than a vocabulary deficit. Results are discussed in terms of dyslexics' difficulty in encoding full segmental phonological representations of names in long-term memory and/or in processing these representations in order to generate required names on demand.

A review and economic evaluation of bronchodilator delivery methods in hospitalized patients

BACKGROUND

Bronchodilator delivery by metered dose inhaler (MDI) to treat airflow obstruction is considered to be less expensive and as effective as nebulized therapy.

OBJECTIVES

To document the utilization of bronchodilator delivery methods in a tertiary care Canadian university teaching hospital and to perform an economic evaluation.

METHODS

A prospective 6-week audit of 4 preselected hospital wards (respiratory, thoracic surgery, general surgery, and a general internal medicine clinical teaching unit) and a cost-minimization economic evaluation were performed. Bronchodilator (salbutamol and ipratropium bromide) doses, frequency, and delivery methods, either MDI or wet nebulizer (WN), were recorded for 95 patients treated with aerosolized bronchodilators. Direct costs for medications and hourly wages including benefits and equipment were obtained. Time and motion studies identified time allocated to MDI and WN delivery. We used sensitivity analyses to test assumptions that could significantly affect treatment costs, especially assumptions about medications, labor, and spacer devices. Costs are expressed in Canadian dollars (Can$1 = US$0.75).

RESULTS

Sixty-seven patients (70.5%) were treated with WN, 6 (6.3%) with MDI, and 22 (23.2%) with both WN and MDI. Self-administration of salbutamol by MDI was the least expensive: $1.27 for 200-microgram doses and $1.73 for 400-microgram doses compared with $2.62 for a 2.5-mg dose delivered by WN. The difference in cost between equivalent treatments (400-microgram MDI vs 2.5-mg WN) is only $0.89. Sensitivity analyses showed that MDI was the least expensive therapy when self-administration was possible and for all levels of supervision if more than 4 minutes was needed to administer a WN treatment.

CONCLUSIONS

Bronchodilator delivery by WN is commonly prescribed for hospitalized patients despite evidence for equivalency of effect using MDI and in the absence of substitution protocols. Previous studies have estimated a far greater cost differential based on unrealistic labor estimates. We found that supervision of patients using MDIs minimized the differential cost between WN and MDI therapy and that cost savings are maximal in patients who can self-administer MDI therapy. Methodologically sound economic evaluations can better identify true cost savings and variables that need further study.

Sequence comparison of putative regulatory DNA of the 5' flanking region of the myeloperoxidase gene in normal and leukemic bone marrow cells

Myeloperoxidase (MPO) is an enzyme which is exclusively expressed in immature myeloid cells with downregulation of gene expression occurring during granulocytic maturation. Levels of MPO RNA, protein, and enzyme activity differ, usually in a concordant fashion, among the various classes of acute leukemia and among different cases within a particular class. One portion of the gene thought to be involved in regulation of MPO expression is the proximal 5' flanking region. To determine if mutations in this putatively regulatory region of the MPO gene might be responsible for some of the differences in level of MPO expression among different cases or classes of acute leukemia, we compared the nucleotide sequence of this part of the gene from 16 patients with acute leukemia, with DNA from normal human bone marrow cells and selected other neoplasms and cell lines. The sequence of this regulatory region was found to be identical in cases of acute myeloid leukemia (AML) with tha of normal DNA except for a dA to dG transition in the Alu region, 463 bases upstream from the transcription start site. This base substitution was seen in almost all cases of AML studied, regardless of the level of MPO which they expressed. It was absent from normal human DNA obtained from various tissues, and cases of acute and chronic lymphocytic leukemia, carcinoma of lung, and most cell lines examined. The base substitution was also absent in a remission blood sample from one of the cases which showed the dA to dG transition in leukemic marrow, suggesting that the base substitution is a mutation rather than a polymorphism. Our results suggest that mutations in promoter or enhancer DNA are not an important cause of the differences in level of MPO gene expression seen among different cases or different classes of AML. However, the base substitution we have detected could potentially serve as a useful marker for detection of residual disease in patients with AML following treatment.

Mutations in the p53 gene in human astrocytomas: detection by single-strand conformation polymorphism analysis and direct DNA sequencing

The p53 gene was examined in a series of formalin-fixed paraffin-embedded astrocytic neoplasms of various types by polymerase chain reaction (PCR), single-strand conformation polymorphism analysis (SSCP), and direct sequencing of amplified DNA. PCR primers were designed to amplify three DNA fragments encompassing exons 5, 7, and 8 with splice sites, including all four mutational "hot spots" within this gene. SSCP was performed in a polyacrylamide gel containing 10% glycerol. Two mutations were found among the 20 high and intermediate grade adult astrocytomas studied by this sensitive screening technique and confirmed by sequencing of the PCR product. (1) An anaplastic astrocytoma disclosed a T-A transversion in Codon 246 giving rise to a methionine to lysine amino acid substitution. (2) A giant cell glioblastoma disclosed a G to A transition in Codon 285 resulting in a glutamic acid to lysine substitution. Both mutations were associated with loss of the normal allele. Twenty-three DNA fragments that disclosed no mutation by SSCP analysis were confirmed to be negative by direct sequencing of amplified DNA. No mutations were detected in a series of eight juvenile cerebellar astrocytomas, a biologically distinct form of low-grade astrocytoma. Mutations of the p53 gene may play an important pathogenetic role in a subset of human astrocytomas.

Human myeloperoxidase gene expression in acute leukemia

To evaluate the relationship between myeloperoxidase (MPO) gene expression and specific lineages of hematopoietic differentiation, we analyzed expression of the MPO gene in a variety of normal and leukemic human cells. As a first step, we synthesized several oligonucleotide probes and isolated cDNA clones for the MPO gene. MPO expression was detected in most acute myeloid leukemias, and the level of expression correlated well with cytochemical enzymatic activity. No MPO message was detected in pure lymphoid leukemias, whereas very low basal levels of MPO transcripts were found in normal bone marrows. In four cases of acute undifferentiated leukemias cytochemically negative for MPO, significant levels of MPO transcripts were detected, suggesting a myeloid origin for these cases. These results indicate that MPO gene expression may serve as an additional marker for subclassification of acute leukemias and may be used to identify leukemic cells arrested at an early stage of the myeloid differentiation pathway.