Validation of epidermal AMBRA1 and loricrin (AMBLor) as a prognostic biomarker for nonulcerated American Joint Committee on Cancer stage I/II cutaneous melanoma

BACKGROUND

Combined expression of the autophagy-regulatory protein AMBRA1 (activating molecule in Beclin1-regulated autophagy) and the terminal differentiation marker loricrin in the peritumoral epidermis of stage I melanomas can identify tumour subsets at low risk of -metastasis.

OBJECTIVES

To validate the combined expression of peritumoral AMBRA1 and loricrin (AMBLor) as a prognostic biomarker able to identify both stage I and II melanomas at low risk of tumour recurrence.

METHODS

Automated immunohistochemistry was used to analyse peritumoral AMBRA1 and loricrin expression in geographically distinct discovery (n = 540) and validation (n = 300) cohorts of nonulcerated American Joint Committee on Cancer (AJCC) stage I and II melanomas. AMBLor status was correlated with clinical outcomes in the discovery and validation cohorts separately and combined.

RESULTS

Analysis of AMBLor in the discovery cohort revealed a recurrence-free survival (RFS) rate of 95.5% in the AMBLor low-risk group vs. 81.7% in the AMBLor at-risk group (multivariate log-rank, P < 0.001) and a negative predictive value (NPV) of 96.0%. In the validation cohort, AMBLor analysis revealed a RFS rate of 97.6% in the AMBLor low-risk group vs. 78.3% in the at-risk group (multivariate log-rank, P < 0.001) and a NPV of 97.6%. In a multivariate model considering AMBLor, Breslow thickness, age and sex, analysis of the combined discovery and validation cohorts showed that the estimated effect of AMBLor was statistically significant, with a hazard ratio of 3.469 (95% confidence interval 1.403-8.580, P = 0.007) and an overall NPV of 96.5%.

CONCLUSIONS

These data provide further evidence validating AMBLor as a prognostic biomarker to identify nonulcerated AJCC stage I and II melanoma tumours at low risk of disease recurrence.

Single-cell insights into immune dysregulation in rheumatoid arthritis flare versus drug-free remission

Immune-mediated inflammatory diseases (IMIDs) are typically characterised by relapsing and remitting flares of inflammation. However, the unpredictability of disease flares impedes their study. Addressing this critical knowledge gap, we use the experimental medicine approach of immunomodulatory drug withdrawal in rheumatoid arthritis (RA) remission to synchronise flare processes allowing detailed characterisation. Exploratory mass cytometry analyses reveal three circulating cellular subsets heralding the onset of arthritis flare - CD45RO+PD1hi CD4+ and CD8+ T cells, and CD27+CD86+CD21- B cells - further characterised by single-cell sequencing. Distinct lymphocyte subsets including cytotoxic and exhausted CD4+ memory T cells, memory CD8+CXCR5+ T cells, and IGHA1+ plasma cells are primed for activation in flare patients. Regulatory memory CD4+ T cells (Treg cells) increase at flare onset, but with dysfunctional regulatory marker expression compared to drug-free remission. Significant clonal expansion is observed in T cells, but not B cells, after drug cessation; this is widespread throughout memory CD8+ T cell subsets but limited to the granzyme-expressing cytotoxic subset within CD4+ memory T cells. Based on our observations, we suggest a model of immune dysregulation for understanding RA flare, with potential for further translational research towards novel avenues for its treatment and prevention.

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.

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.

Does Every Minute Really Count? Road Time as an Indicator for the Economic Value of Emergency Medical Services

OBJECTIVES

This article builds on the literature regarding the association between emergency medical service (EMS) response times and patient outcomes (death and severe injury). Three issues are addressed in this article with respect to the empirical estimation of this relationship: the endogeneity of response time (systematically quicker response for higher degrees of urgency), the nonlinearity of this relationship, and the variation between such estimations for different patient outcomes.

METHODS

Binomial and multinomial logistic regression models are used to estimate the impact of response time on the probabilities of death and severe injury using data from French Fire and Rescue Services. These models are developed with response time as an explanatory variable and then with road time (dispatch to arrival) hypothesized as representing the exogenous variation within response time. Both models are also applied to data subsets based on response time intervals.

RESULTS

The results show that road time yields a higher estimate for the impact of response time on patient outcomes than (total) response time. The impact of road time on patient outcomes is also shown to be nonlinear. These results are of both statistical significance (model coefficients are significant at the 95% confidence level) and economical significance (when taking into account the number of annual interventions performed).

CONCLUSIONS

When using heterogeneous data on EMS interventions where endogeneity is a clear issue, road time is a more reliable indicator to estimate the impact of EMS response time on patient outcomes than (total) response time.

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.

Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data

BACKGROUND

In late March 2020, a "Stay Home, Stay Healthy" order was issued in Washington State in response to the COVID-19 pandemic. On May 1, a 4-phase reopening plan began. We investigated whether adjunctive prevention strategies would allow less restrictive physical distancing to avoid second epidemic waves and secure safe school reopening.

METHODS

We developed a mathematical model, stratifying the population by age, infection status and treatment status to project SARS-CoV-2 transmission during and after the reopening period. The model was parameterized with demographic and contact data from King County, WA and calibrated to confirmed cases, deaths and epidemic peak timing. Adjunctive prevention interventions were simulated assuming different levels of pre-COVID physical interactions (pC_PI) restored.

RESULTS

The best model fit estimated ~35% pC_PI under the lockdown which prevented ~17,000 deaths by May 15. Gradually restoring 75% pC_PI for all age groups between May 15-July 15 would have resulted in ~350 daily deaths by early September 2020. Maintaining <45% pC_PI was required with current testing practices to ensure low levels of daily infections and deaths. Increased testing, isolation of symptomatic infections, and contact tracing permitted 60% pC_PI without significant increases in daily deaths before November and allowed opening of schools with <15 daily deaths. Inpatient antiviral treatment was predicted to reduce deaths significantly without lowering cases or hospitalizations.

CONCLUSIONS

We predict that widespread testing, contact tracing and case isolation would allow relaxation of physical distancing, as well as opening of schools, without a surge in local cases and deaths.

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.

Rapid localized spread and immunologic containment define Herpes simplex virus-2 reactivation in the human genital tract

Herpes simplex virus-2 (HSV-2) is shed episodically, leading to occasional genital ulcers and efficient transmission. The biology explaining highly variable shedding patterns, in an infected person over time, is poorly understood. We sampled the genital tract for HSV DNA at several time intervals and concurrently at multiple sites, and derived a spatial mathematical model to characterize dynamics of HSV-2 reactivation. The model reproduced heterogeneity in shedding episode duration and viral production, and predicted rapid early viral expansion, rapid late decay, and wide spatial dispersion of HSV replication during episodes. In simulations, HSV-2 spread locally within single ulcers to thousands of epithelial cells in <12 hr, but host immune responses eliminated infected cells in <24 hr; secondary ulcers formed following spatial propagation of cell-free HSV-2, allowing for episode prolongation. We conclude that HSV-2 infection is characterized by extremely rapid virological growth and containment at multiple contemporaneous sites within genital epithelium.

DOI:http://dx.doi.org/10.7554/eLife.00288.001

Viruses infect organisms as diverse as unicellular bacteria, plants, and animals. Two well-known human viral infections are herpes simplex virus 1, which is responsible for most cold sores, and herpes simplex virus 2 (HSV-2), which causes most cases of genital herpes. The first signs of HSV-2 infection are genital lesions, which usually heal relatively quickly. However, the virus can also enter nerve cells, where it hides from the immune system and survives for the lifetime of the infected host. In a process that is not fully understood, the dormant viruses inside nerve cells periodically reactivate and are transported back to the genital tract where they can cause recurrent genital sores. HSV-2 also commonly replicates in genital skin when lesions are not present, and is efficiently transmitted to other individuals at these times.

Most studies of viral infection rely on the examination of blood to determine viral load and characterize the immune response. However, the true battle between HSV-2 and its host occurs within genital tissues. HSV-2 lesions are clearly visible and it is therefore possible to precisely follow the number of viruses and the intensity of the host immune response as a function of time and position. Schiffer et al. follow this approach by examining the levels of HSV-2 DNA in the genital tracts of over 600 individuals, who were sampled at different time intervals and at multiple sites. Dramatic differences in the viral load and the density of CD8+ T cells, which are critical for controlling HSV-2, are observed across several millimeters of the skin. Viral load also varies dramatically over a few hours. These data are used to develop a mathematical model that characterizes the spatial dynamics of HSV-2 reactivation and suggests how the host immune system responds to reactivation.

Historically, it was thought that host immune cells, including CD8+ T cells, required many days to contain an HSV-2 reactivation, allowing prolonged symptoms. However, the model developed by Schiffer et al. indicates that although viral infection can spread from a single skin cell to thousands of cells in 12 hr or so, the host immune cells typically clear all infected skin cells in under 24 hr. Episodes of viral shedding lasting >3 days are predicted to occur due to viral seeding of adjacent regions of genital skin.

Schiffer et al. predict that the complex episodic nature of HSV-2 reactivation is heavily influenced by the spatial distribution and density of immune cells within the genital tract, which means that new lesions occur in regions where immune cell density is low. The rapid onset and localized clearance pattern suggests that viral elimination by skin-resident CD8⁺ T cells is actually highly effective within single genital ulcers. This hypothesis represents an area of intense current investigation for clinicians, virologists, mathematical modelers, and immunologists.

DOI:http://dx.doi.org/10.7554/eLife.00288.002

Analysis of HIV using a high resolution melting (HRM) diversity assay: automation of HRM data analysis enhances the utility of the assay for analysis of HIV incidence

BACKGROUND

HIV diversity may be a useful biomarker for discriminating between recent and non-recent HIV infection. The high resolution melting (HRM) diversity assay was developed to quantify HIV diversity in viral populations without sequencing. In this assay, HIV diversity is expressed as a single numeric HRM score that represents the width of a melting peak. HRM scores are highly associated with diversity measures obtained with next generation sequencing. In this report, a software package, the HRM Diversity Assay Analysis Tool (DivMelt), was developed to automate calculation of HRM scores from melting curve data.

METHODS

DivMelt uses computational algorithms to calculate HRM scores by identifying the start (T1) and end (T2) melting temperatures for a DNA sample and subtracting them (T2 - T1 =  HRM score). DivMelt contains many user-supplied analysis parameters to allow analyses to be tailored to different contexts. DivMelt analysis options were optimized to discriminate between recent and non-recent HIV infection and to maximize HRM score reproducibility. HRM scores calculated using DivMelt were compared to HRM scores obtained using a manual method that is based on visual inspection of DNA melting curves.

RESULTS

HRM scores generated with DivMelt agreed with manually generated HRM scores obtained from the same DNA melting data. Optimal parameters for discriminating between recent and non-recent HIV infection were identified. DivMelt provided greater discrimination between recent and non-recent HIV infection than the manual method.

CONCLUSION

DivMelt provides a rapid, accurate method of determining HRM scores from melting curve data, facilitating use of the HRM diversity assay for large-scale studies.

Prevalence of genital human papillomavirus among females in the United States, the National Health And Nutrition Examination Survey, 2003-2006

BACKGROUND

Genital human papillomaviruses (HPV) include >40 sexually transmitted viruses. Most HPV infections do not progress to disease, but infection with certain types of HPV can cause cervical and other anogenital and oropharyngeal cancer, and other types of HPV are associated with anogenital warts. HPV vaccines prevent infection with HPV 16 and 18, which account for 70% of cases of cervical cancer, and HPV 6 and 11, which cause 90% of the cases of anogenital warts.

METHODS

Using data and self-collected cervicovaginal specimens from 4150 females, 14-59 years of age, from consecutive National Health and Nutrition Examination Surveys (2003-2006), we estimated the prevalence of type-specific HPV DNA and examined sociodemographic and sexual determinants.

RESULTS

The overall prevalence of HPV was 42.5% in females 14-59 years of age and varied significantly by age, race or ethnicity, and number of sex partners. Individual type prevalence was less than 7%, ranging from <0.5% through 6.5%. The most common type was nononcogenic HPV 62 (found in 6.5% of subjects), followed by HPV 53 and HPV 16 (4.7%), both of which are oncogenic types. The most prevalent species was nononcogenic α3.

CONCLUSIONS

HPV infection is common among US females, with the highest burden of infection found in young females 20-24 years of age. Monitoring trends in HPV type distribution will contribute to our understanding of the early impact of HPV vaccines.

Longitudinal Measures of Human Papillomavirus 6 and 11 Viral Loads and Antibody Response in Children With Recurrent Respiratory Papillomatosis

OBJECTIVES

To measure human papillomavirus (HPV) 6 and 11 viral load and antibody response in longitudinal specimens obtained from children with recurrent respiratory papillomatosis and to examine the association of type-specific viral load with clinical severity of disease.

DESIGN

Longitudinal pilot study with a median follow-up of 5.4 months.

SUBJECTS

The study included 15 children undergoing therapy for recurrent respiratory papillomatosis at the Egleston Children's Hospital, Atlanta, GA, between January 22, 1999, and June 13, 2000.

MAIN OUTCOME MEASURES

The kinetics of HPV-6 and HPV-11 viral load and antibody level were examined over time. Longitudinal HPV-6 and HPV-11 viral loads were analyzed for associations with clinical indicators of disease severity.

RESULTS

Four children were infected with HPV-11, 4 were infected with HPV-6, and 7 had mixed infections. The HPV-6 and HPV-11 viral loads were stable over time in most of the children. Among children with mixed infections, HPV-6 viral loads were inversely correlated with those of HPV-11 (r = -0.80, P<.001). The HPV-11 infection was significantly associated with more annual surgical procedures (P=.02). Neither HPV-6 nor HPV-11 viral loads were associated with demographic factors or markers of clinical severity. None of the children had detectable antibodies against HPV-6, and only 3 had detectable antibodies against HPV-11 virallike particles.

CONCLUSIONS

Our data support the association of HPV-11 infection with clinical severity. Measures of HPV-6 and HPV-11 viral loads are relatively stable over time in most children with recurrent respiratory papillomatosis, suggesting that multiple samples may not be necessary. Cytobrush samples may substitute for tissue biopsy specimens in HPV detection and typing, but not for absolute viral load determination.

Correlates of cervical mucosal antibodies to human papillomavirus 16: Results from a case control study

BACKGROUND

While the cervical mucosal immune response to human papillomavirus (HPV) infection is believed to be central to viral clearance, it is not well characterized. We performed this analysis to determine correlates of HPV-16-specific mucosal antibody response in women at high risk for infection with HPV.

METHODS

Cervical mucosal and serum samples were obtained from participants in a case control study that measured demographic risk factors of cervical disease and HPV infection. An HPV-16 L1-virus-like particle ELISA was used to detect HPV-16-specific IgA and IgG. Antibody level results were correlated with demographic characteristics, sexual history, cervical disease, and HPV detection.

RESULTS

Cervical anti-HPV-16 IgA and IgG inversely correlated with HPV DNA, HPV-16 DNA, and cervical disease.

CONCLUSIONS

These findings suggest that mucosal antibodies may protect against HPV infection and cervical disease. However, additional longitudinal studies evaluating serum and mucosal antibody correlates of incident, persistent, and clearing HPV infection are needed. In addition, standardization of mucosal sample collection and testing methods are required.

Association of Chlamydia trachomatis with persistence of high-risk types of human papillomavirus in a cohort of female adolescents

Human papillomavirus (HPV) infection is a necessary but not sufficient cause of cervical cancer. While chlamydia infection has been associated with cervical cancer, the meaning of this association remains unclear. The authors' objective was to investigate this association by evaluating whether concurrent genital tract infections are associated with HPV persistence, a precursor to cervical cancer. Interview data and biologic samples for HPV, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and bacterial vaginosis testing were collected from female adolescents in an Atlanta, Georgia, longitudinal cohort study at 6-month visits (1999-2003). Associations with persistence (detection of the same HPV type at two sequential visits (visit pair)) were assessed among subjects with 2-5 visits and > or =6 months of follow-up. Associations were evaluated by logistic regression using methods for correlated data. Type-specific persistence of high-risk HPV types was detected in 77 of 181 (43%) analyzed visit pairs. Concurrent infection with C. trachomatis was independently associated with persistence of high-risk HPV types (adjusted odds ratio = 2.1, 95% confidence interval: 1.0, 4.1). Infection with more than one HPV type at the initial visit was also associated with high-risk persistence (adjusted odds ratio = 2.8, 95% confidence interval: 1.6, 4.9). The association between chlamydia infection and cervical cancer may be due to an effect of chlamydia infection on persistence of high-risk HPV.

A Theileria annulata DNA binding protein localized to the host cell nucleus alters the phenotype of a bovine macrophage cell line

The apicomplexan parasite Theileria annulata is the only intracellular eukaryote that is known to induce the proliferation of mammalian cells. However, as the parasite undergoes stage differentiation, host cell proliferation is inhibited, and the leukocyte is eventually destroyed. We have isolated a parasite gene (SuAT1) encoding an AT hook DNA binding polypeptide that has a predicted signal peptide, PEST motifs, nuclear localization signals, and domains which indicate interaction with regulatory components of the higher eukaryotic cell cycle. The polypeptide is localized to the nuclei of macroschizont-infected cells and was detected at significant levels in cells that were undergoing parasite stage differentiation. Transfection of an uninfected transformed bovine macrophage cell line, BoMac, demonstrated that SuAT1 can modulate cellular morphology and alter the expression pattern of a cytoskeletal polypeptide in a manner similar to that found during the infection of leukocytes by the parasite. Our findings indicate that Theileria parasite molecules that are transported to the leukocyte nucleus have the potential to modulate the phenotype of infected cells.

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.

Generation of hybrid human immunodeficiency virus by homologous recombination

Human immunodeficiency virus (HIV) type 1, isolated from diverse sources, exhibits genomic diversity. The mechanisms by which the genomic diversity takes place in individuals exposed to multiple virus isolates is yet to be elucidated. Genetic variation, in general, might result from mutagenic events such as point mutations, rearrangements (insertions and deletions), and recombination. In an attempt to evaluate the process of genetic diversity, we designed experiments to analyze recombination between HIV DNAs by using DNA transfection in cell cultures. Here we report the successful recombination between truncated HIV proviral DNAs with an overlap homology of 53 base pairs that leads to the formation of viable hybrid virus. Recombination was also seen between exogenous DNA introduced into cells and homologous HIV sequences resident in the cells. These results indicate that recombination among various HIV isolates may play a significant role in the generation of genetic diversity of HIV. Further, the method used here enables the construction of hybrid HIV genomes to identify the viral determinants responsible for tropism, replication, and cytopathic effects.

Translocation of the c-myc gene into the immunoglobulin heavy chain locus in human Burkitt lymphoma and murine plasmacytoma cells

The consistent appearance of specific chromosomal translocations in human Burkitt lymphomas and murine plasmacytomas has suggested that these translocations might play a role in malignant transformation. Here we show that transformation of these cells is frequently accompanied by the somatic rearrangement of a cellular analogue of an avian retrovirus transforming gene, c-myc. Moreover, we map c-myc to human chromosome 8 band q24, the chromosomal segment involved in the reciprocal Burkitt translocations [t(8;14), t(8;22) and t(2;8)]. In two t(8;14) human Burkitt cell lines, c-myc appears to have been translocated directly into a DNA restriction fragment that also encodes the immunoglobulin mu chain gene. In the case of a specific cloned fragment of DNA derived from a mouse plasmacytoma, we demonstrate directly that c-myc has been translocated into the immunoglobulin alpha switch region. Our data provide a molecular basis for considering the role that specific translocations might play in malignant transformation.

Chromosomal localization of the Moloney sarcoma virus mouse cellular (c-mos) sequence

The Moloney sarcoma virus-specific onc gene, referred to as v-mos, was used as probe to hybridize to restricted DNAs from various mouse-Chinese hamster hybrid cell lines. These hybrid cells contain, in addition to all of the Chinese hamster chromosomes, various numbers (less than a full complement) of mouse chromosomes. Comparison of the presence or absence of the mouse cellular mos gene with the known karyotype in each of the hybrid cell lines allows us to conclude that the mos gene is on mouse chromosome 4.

A processed human immunoglobulin epsilon gene has moved to chromosome 9

Processed genes--genes that resemble processed RNA transcripts rather than interrupted genomic sequences--have been identified as dispersed members of several gene families. Here we describe a processed gene that is one of the three human IgE-like sequences present in the human genome. The processed IgE gene has precisely lost its three intervening sequences, thereby fusing its four coding domains. The homology of the gene to its functional counterpart ends in an adenine-rich tail followed by an 11-base-pair sequence that is directly repeated 150 base pairs 5' to its first coding domain. In addition, the processed gene is located on human chromosome 9 rather than on chromosome 14, the site of the active immunoglobulin locus. The structure and evident mobility of this sequence support the concept that sequences can move about in the genome via RNA intermediates and that processed genes are a prominent feature of genomic structure.

Chromosomal location of human kappa and lambda immunoglobulin light chain constant region genes

The chromosomal location of human constant region light chain immunoglobulin (Ig) genes has been determined by analyzing a group of human fibroblast/rodent somatic cell hybrids with nucleic acid probes prepared from cloned human kappa and lambda constant region genes. Human chromosomes in each cell line were identified by isoenzyme analysis. The DNA from hybrid cells was digested with restriction endonucleases, size fractionated by gel electrophoresis, transferred to nitrocellulose or DBM paper, and hybridized with (32)P-labeled nucleic acid probes. The C(kappa) gene was assigned to human chromosome 2 and the C(lambda) genes to chromosome 22, based upon analysis of these hybrid cell lines, and these assignments were confirmed by analysis of subclones. A group of previously unassigned loci can be mapped to chromosome 2 by virtue of their close linkage to C(kappa). The lambda and kappa light chain and heavy chain Ig genes have now been assigned to all three human chromosomes that are involved in translocations with chromosome 8 in human B cell neoplasms. These techniques and probes provide a means to study the detailed arrangement of human Ig genes and their pseudogenes.