Serological biomarker screening and host factor analysis elucidating immune response heterogeneity in active pulmonary tuberculosis

While mortality and morbidity from pulmonary tuberculosis (PTB) have improved, diagnosis of this infectious disease remains suboptimal without a point-of-care test. Antibody/ antigen-based serodiagnostics is the most amenable for point-of-care translation but hampered by a lack of validated biomarkers and a heterogeneous patient antibody response. Using a case-control design, we assessed serodiagnostic potential of immunoglobulins G, A, and dimeric IgA responses against 18 antigenic preparations, followed by antibody-subclass responses against antigen 60 (A60), and four markers of host innate immunity by enzymelinked immunoassay using sera samples (n=110) collected from April to October 2007 in VietNam from human immunodeficiency-negative patients with provisional diagnosis of PTB. We further analyzed host variables to investigate factors driving biomarker heterogeneity observed in patients. Among active pulmonary tuberculosis patients, low correlation was observed between anti-A60 antibody-classes, and between anti-A60 immunoglobulin G subclasses, but anti-A60 immunoglobulin A subclasses were significantly correlated. The best diagnostic combination of anti-A60 immunoglobulin G/A and a C-reactive protein "ruleout" remains insufficient at 82%/92% sensitivity/specificity (95%CI: 72-92%/82-98%). Heterogeneity of anti-A60 immunoglobulins G2, G3, M, as well as C-reactive protein and serum amyloid A levels observed in this study population appeared to be significantly associated with history of previous tuberculosis, hemoptysis, age, vaccination, night sweats, smoking, chest pain, fever, alcohol, and solid culture count. Further research on tuberculosis serological biomarkers may require consideration of host factors and new approaches using multiple biomarkers.

Selective Targeting of High-Affinity LFA-1 Does Not Augment Costimulation Blockade in a Nonhuman Primate Renal Transplantation Model

Costimulation blockade (CoB) via belatacept is a lower-morbidity alternative to calcineurin inhibitor (CNI)-based immunosuppression. However, it has higher rates of early acute rejection. These early rejections are mediated in part by memory T cells, which have reduced dependence on the pathway targeted by belatacept and increased adhesion molecule expression. One such molecule is leukocyte function antigen (LFA)-1. LFA-1 exists in two forms: a commonly expressed, low-affinity form and a transient, high-affinity form, expressed only during activation. We have shown that antibodies reactive with LFA-1 regardless of its configuration are effective in eliminating memory T cells but at the cost of impaired protective immunity. Here we test two novel agents, leukotoxin A and AL-579, each of which targets the high-affinity form of LFA-1, to determine whether this more precise targeting prevents belatacept-resistant rejection. Despite evidence of ex vivo and in vivo ligand-specific activity, neither agent when combined with belatacept proved superior to belatacept monotherapy. Leukotoxin A approached a ceiling of toxicity before efficacy, while AL-579 failed to significantly alter the peripheral immune response. These data, and prior studies, suggest that LFA-1 blockade may not be a suitable adjuvant agent for CoB-resistant rejection.

Dietary restraint: what's the harm? A review of the relationship between dietary restraint, weight trajectory and the development of eating pathology

Dietary restraint has historically been implicated as a risk factor for the development of eating pathology. Despite existing findings, recent research suggests that many individuals are capable of practicing dietary restraint without negative effects. In order to successfully incorporate the positive aspects of dietary restraint into interventions for healthy weight management, a nuanced examination of the relationship between dietary restraint and resulting eating patterns is necessary. Accordingly, the current review seeks to clarify the existing literature with regard to dietary restraint. First, this review examines the construct of dietary restraint and differentiates dietary restraint from related constructs, such as weight loss dieting. Second, it identifies situations in which dietary restraint has been linked with positive outcomes, such as healthy weight management and prevention of eating pathology. Altogether, it appears that dietary restraint can prove a beneficial strategy for those attempting to control their weight, as it does not relate to increased levels of eating pathology when practiced as part of a well-validated weight management programme.

Participation as a leader in immersion weight loss treatment: a 1-year follow-up study

Non-overweight individuals may follow aggressive weight management approaches alongside overweight/obese friends or family members; thus, research has begun to evaluate subsequent effects among non-overweight populations. A prior study evaluated the short-term effects of an immersion weight loss programme on healthy young adult staff leaders. Results indicated that participation seemed to benefit, not harm, the young adults. The current investigation examined 1-year eating disorder and weight trajectories in this sample. The total sample (N = 244) consisted of staff leaders (44.3%) and demographically similar comparison participants who completed eating disorder and weight assessments across four time points: baseline, end of summer, 6-week follow-up and 1-year follow-up. Forty-seven per cent of the original sample responded to all time points (staff leaders n = 60; comparison n = 55). Over the course of 1 year, risk trajectories did not differ between groups. Staff leaders did not report significant changes in body mass index, suggesting that they maintained healthy weight over the course of 1 year. Participation as an immersion weight loss programme leader appeared to be protective against weight gain, without increasing eating disorder risk, for healthy young adults. This provides further support for using weight management interventions across a wide range of individuals.

Participation as a leader in immersion weight loss treatment may benefit, not harm, young adult staff members

Despite the success of weight-management programmes, some researchers caution that participation in an aggressive approach to weight management could promote the development of eating pathology. The current study evaluated the risks and benefits for young adults of serving as staff members in an immersion treatment of adolescent obesity over the course of a summer. Participants included weight loss staff members (n = 108) along with a comparison group of young adults with similar demographic characteristics (n = 136). Participants completed assessments of eating disorder and obesity risk at three time points: the beginning of the summer, the end of the summer and a 6-week follow-up. Weight loss leadership participants who were initially overweight lost weight over the course of the summer, but those at healthy weights maintained their weight. Comparison participants also maintained their weight during the summer. Weight loss staff members also increased dietary restraint over the summer, and increases in dietary restraint appeared to facilitate appropriate weight reduction. Participation as a leader in an immersion weight loss programme seemed to benefit, not harm, young adults; this suggests potential advantages for using weight controlling interventions in a wide range of individuals, including as an obesity prevention strategy.

Public health implications of molecular point-of-care testing for chlamydia and gonorrhoea in remote primary care services in Australia: a qualitative study

OBJECTIVES

With accurate molecular tests now available for diagnosis of chlamydia and gonorrhoea (Chlamydia trachomatis (CT)/Neisseria gonorrhoeae (NG)) at the point-of-care (POC), we aimed to explore the public health implications (benefits and barriers) of their integration into remote primary care in Australia.

METHODS

Qualitative interviews were conducted with a purposively selected group of 18 key informants reflecting sexual health, primary care, remote Aboriginal health and laboratory expertise.

RESULTS

Participants believed that POC testing may decrease community prevalence of sexually transmitted infections (STIs), and associated morbidity by reducing the time to treatment and infectious period and expediting partner notification. Also, POC testing could improve acceptability of STI testing, increase testing coverage and result in more targeted prescribing, thereby minimising the risk of antibiotic resistance. Conversely, some felt the immediacy of diagnosis could deter certain young people from being tested. Participants also noted that POC testing may reduce the completeness of communicable disease surveillance data given the current dependence on reporting from pathology laboratories. Others expressed concern about the need to maintain and improve the flow of NG antibiotic sensitivity data, already compromised by the shift to nucleic acid-based testing. This is particularly relevant to remote areas where culture viability is problematic.

CONCLUSIONS

Results indicate a high level of support from clinicians and public health practitioners for wider access to CT/NG POC tests citing potential benefits, including earlier, more accurate treatment decisions and reductions in ongoing transmission. However, the data also highlight the need for new systems to avoid adverse impact on disease surveillance.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trials Registry: ACTRN12613000808741.

Photoassociation of long-range nD Rydberg molecules

We observe long-range homonuclear diatomic nD Rydberg molecules photoassociated out of an ultracold gas of Rb87 atoms for 34≤n≤40. The measured ground-state binding energies of Rb87(nD+5S1/2) molecular states are larger than those of their Rb87(nS+5S1/2) counterparts, which shows the dependence of the molecular bond on the angular momentum of the Rydberg atom. We exhibit the transition of Rb87(nD+5S1/2) molecules from a molecular-binding-dominant regime at low n to a fine-structure-dominant regime at high n [akin to Hund's cases (a) and (c), respectively]. In the analysis, the fine structure of the nD Rydberg atom and the hyperfine structure of the 5S1/2 atom are included.

Residual vein obstruction as a predictor for recurrent thromboembolic events after a first unprovoked episode: data from the REVERSE cohort study

OBJECTIVES

There is growing interest in using residual vein obstruction (RVO) to guide the duration of oral anticoagulant therapy (OAT) for unprovoked deep vein thrombosis (DVT). We sought to determine if RVO as determined by compression ultrasonography (CUS) after completion of 5-7 months of anticoagulation for unprovoked DVT is associated with an increased risk of recurrent venous thromboembolism (VTE).

MATERIALS AND METHODS

This was a multicentre multinational prospective cohort study undertaken in tertiary care centers. Patients with a first 'unprovoked' major VTE were enrolled over a 4-year period and completed a mean 18-month follow-up in September 2006. All 452 patients with DVT had baseline CUS at inclusion to assess any RVO before stopping OAT at 5-7 months. During follow-up off OAT, all episodes of suspected recurrent VTE were independently adjudicated with reference to baseline imaging.

RESULTS

Forty-five out of 231 patients with abnormal CUS (19.5%) had recurrent VTE during follow-up, as compared with 32 out of 220 patients with normal CUS (14.6%), and one patient had inadequate CUS. There was no significant association between an abnormal CUS at inclusion and the risk of recurrent VTE: hazard ratio 1.4 (95% confidence interval, 0.9-2.1), P=0.19. None of the different degrees of clot resolution on baseline CUS was statistically significantly associated with the risk of recurrent VTE.

CONCLUSION

In our study, the presence of RVO at the time of OAT withdrawal was not associated with a statistically significant higher risk of recurrent VTE. RVO assessment may not be useful to guide duration of anticoagulation.

A controlled comparison of the word repeating technique with a word association task

The Word Repeating Technique (WRT) is a cognitive defusion technique used in Acceptance and Commitment Therapy (ACT). In this exercise, a word or short phrase is quickly repeated aloud until the context required for the word to have literal meaning changes. This study compared the WRT to a procedure that requires words to retain their meaning [the Implicit Associations Task (IAT)]. If the WRT operates by inducing a loss of meaning in words, one would not expect similar effects from a task requiring literal processing of words. Participants (N = 160) completed either the WRT or IAT with or without a theoretically consistent rationale for performing the task, while an additional 40 participants were in a control condition. Both the WRT and IAT decreased discomfort and believability ratings from pre- to post-test for words that were targeted in the tasks, with the WRT resulting in a larger pre- to post-test decrease for discomfort ratings. Only the WRT decreased the discomfort of words not targeted in the task from pre- to post-test, while neither task decreased the believability of words that were not targeted in the tasks. Providing a rationale did not have an effect for either task. Although the strengths of the effects for the WRT were larger than those for the IAT, both tasks demonstrated effects in the same direction and neither demonstrated effects that were larger in magnitude than what was accounted for by regression to the mean.

Patients with a first symptomatic unprovoked deep vein thrombosis are at higher risk of recurrent venous thromboembolism than patients with a first unprovoked pulmonary embolism

BACKGROUND

Previous studies are mixed as to whether patients with unprovoked pulmonary embolism (PE) have a higher rate of venous thromboembolism (VTE) recurrence after anticoagulation is discontinued than patients with unprovoked deep vein thrombosis (DVT).

OBJECTIVES

To determine whether patients with unprovoked PE have a higher rate of VTE recurrence than patients with unprovoked DVT in a prospective multicenter cohort study.

PATIENTS/METHODS

Six hundred and forty-six patients with a first episode of symptomatic unprovoked VTE were treated with heparin and subsequent oral anticoagulation for 5-7 months, and were followed every 6 months for recurrent VTE after their anticoagulant therapy was discontinued.

RESULTS

Of 646 patients, 194 had isolated PE, 339 had isolated DVT, and 113 had both DVT and PE. After a mean of 18 months of follow-up, there were 91 recurrent VTE events (9.5% annualized risk of recurrent VTE in the total population). The crude recurrent VTE rate for the isolated PE, isolated DVT and DVT and PE groups were 7.7%, 16.5% and 17.7%, respectively. The relative risk of recurrent VTE for isolated DVT vs. isolated PE was 2.1 (95% confidence interval 1.2-3.7).

CONCLUSIONS

This study has demonstrated that patients with a first episode of unprovoked isolated DVT are 2.1 times more likely to have a recurrent VTE episode than patients with a first episode of unprovoked isolated PE. These findings need to be considered when determining the optimal duration of anticoagulant therapy for patients with unprovoked VTE.

Validation of a diagnostic approach to exclude recurrent venous thromboembolism

SUMMARY INTRODUCTION

The diagnosis of recurrent venous thromboembolism (VTE) is a challenge in clinical practice. Our objective was to evaluate the safety of a diagnostic strategy utilizing comparison of diagnostic test results with baseline imaging results to rule out suspected recurrent VTE.

METHODS

The REVERSE study was a prospective cohort study whose primary aim was to develop a clinical prediction rule for recurrent VTE. We included and followed patients who completed 5-7 months of anticoagulant therapy after a first unprovoked VTE. Suspected cases of recurrent VTE were assessed according to standardized diagnostic criteria based on comparison of diagnostic test results with those obtained at the time of anticoagulant treatment withdrawal.

RESULTS

Out of the 398 suspected events, a recurrent VTE was diagnosed in 106 cases (26.6%) and excluded in 292 cases. In 76 cases (19%), the diagnosis of recurrent VTE was excluded on the basis of the fact that no significant change on diagnostic imaging was detected when compared to baseline imaging. During the ensuing 3 months, six patients received anticoagulant therapy after recurrent VTE was excluded, and two were lost to follow-up. Eight of 284 remaining patients in whom recurrent VTE had been excluded, who were not treated and who were not lost to follow-up were diagnosed with subsequent VTE (3-month risk, 2.8%; 95% confidence interval, 1.4-5.5%). Six of these eight patients with subsequent recurrent VTE had a known superficial or distal thrombosis at the time of initial suspected recurrent VTE.

CONCLUSION

A diagnostic strategy comparing diagnostic test results obtained at the time of the suspected recurrent event with those obtained at baseline can safely and effectively rule out recurrent VTE in a significant proportion of patients. Registered at http://www.clinicaltrials.gov identifier: NCT00261014.

Vegetative buffers for fan emissions from poultry farms: 2. ammonia, dust and foliar nitrogen

This study evaluated the potential of trees planted around commercial poultry farms to trap ammonia (NH(3)) and dust or particulate matter (PM). Norway spruce, Spike hybrid poplar, hybrid willow, and Streamco purpleosier willow were planted on five commercial farms from 2003 to 2004. Plant foliage was sampled in front of the exhaust fans and at a control distance away from the fans on one turkey, two laying hen, and two broiler chicken farms between June and July 2006. Samples were analyzed for dry matter (DM), nitrogen (N), and PM content. In addition, NH(3) concentrations were measured downwind of the exhaust fans among the trees and at a control distance using NH(3) passive dosi-tubes. Foliage samples were taken and analyzed separately based on plant species. The two layer farms had both spruce and poplar plantings whereas the two broiler farms had hybrid willow and Streamco willow plantings which allowed sampling and species comparisons with the effect of plant location (control vs. fan). The results showed that NH(3) concentration h(- 1) was reduced by distance from housing fans (P < or = 0.0001), especially between 0 m (12.01 ppm), 11.4 m (2.59 ppm), 15 m (2.03 ppm), and 30 m (0.31 ppm). Foliar N of plants near the fans was greater than those sampled away from the fans for poplar (3.87 vs. 2.56%; P < or = 0.0005) and hybrid willow (3.41 vs. 3.02%; P < or = 0.05). The trends for foliar N in spruce (1.91 vs. 1.77%; P = 0.26) and Streamco willow (3.85 vs. 3.33; P = 0.07) were not significant. Pooling results of the four plant species indicated greater N concentration from foliage sampled near the fans than of that away from the fans (3.27 vs. 2.67%; P < or = 0.0001). Foliar DM concentration was not affected by plant location, and when pooled the foliar DM of the four plant species near the fans was 51.3% in comparison with 48.5% at a control distance. There was a significant effect of plant location on foliar N and DM on the two layer farms with greater N and DM adjacent to fans than at a control distance (2.95 vs. 2.15% N and 45.4 vs. 38.2% DM, respectively). There were also significant plant species effects on foliar N and DM with poplar retaining greater N (3.22 vs. 1.88%) and DM (43.7 vs. 39.9%) than spruce. The interaction of location by species (P < or = 0.005) indicated that poplar was more responsive in terms of foliar N, but less responsive for DM than spruce. The effect of location and species on foliar N and DM were not clear among the two willow species on the broiler farms. Plant location had no effect on plant foliar PM weight, but plant species significantly influenced the ability of the plant foliage to trap PM with spruce and hybrid willow showing greater potential than poplar and Streamco willow for PM(2.5)(0.0054, 0.0054, 0.0005, and 0.0016 mg cm(- 2); P < or = 0.05) and total PM (0.0309, 0.0102, 0.0038, and 0.0046 mg cm(- 2), respectively; P < or = 0.001). Spruce trapped more dust compared to the other three species (hybrid willow, poplar, and Streamco willow) for PM(10) (0.0248 vs. 0.0036 mg cm(- 2); P < or = 0.0001) and PM(> 10) (0.0033 vs. 0.0003 mg cm(- 2); P = 0.052). This study indicates that poplar, hybrid willow, and Streamco willow are appropriate species to absorb poultry house aerial NH(3)-N, whereas spruce and hybrid willow are effective traps for dust and its associated odors.

A hydrophobic domain in the large envelope protein is essential for fusion of duck hepatitis B virus at the late endosome

The duck hepatitis B virus (DHBV) envelope is comprised of two transmembrane (TM) proteins, the large (L) and the small (S), that assemble into virions and subviral particles. Secondary-structure predictions indicate that L and S have three alpha-helical, membrane-spanning domains, with TM1 predicted to act as the fusion peptide following endocytosis of DHBV into the hepatocyte. We used bafilomycin A1 during infection of primary duck hepatocytes to show that DHBV must be trafficked from the early to the late endosome for fusion to occur. Alanine substitution mutations in TM1 of L and S, which lowered TM1 hydrophobicity, were used to examine the role of TM1 in infectivity. The high hydrophobicity of the TM1 domain of L, but not of S, was shown to be essential for virus infection at a step downstream of receptor binding and virus internalization. Using wild-type and mutant synthetic peptides, we demonstrate that the hydrophobicity of this domain is required for the aggregation and the lipid mixing of phospholipid vesicles, supporting the role of TM1 as the fusion peptide. While lipid mixing occurred at pH 7, the kinetics of insertion of the fusion peptide was increased at pH 5, consistent with the location of DHBV in the late-endosome compartment and previous studies of the nonessential role of low pH for infectivity. Exchange of the TM1 of DHBV with that of hepatitis B virus yielded functional, infectious DHBV particles, suggesting that TM1 of all of the hepadnaviruses act similarly in the fusion mechanism.

A survey of the use of assessment instruments by eating disorder professionals in clinical practice

Accurate assessment is important in all phases of the treatment process, but there is little information about the assessment procedures utilized by those treating eating disorders in clinical practice. This study surveyed the assessment practices of eating disorder specialists. A brief questionnaire was sent to 480 eating disorder specialists in clinical practice; 95 were returned (19.8% return rate). The questionnaire asked specific questions about what assessment methods and measures they used for initial assessment and diagnosis as well as for treatment outcome. A significant minority of respondents used no validated measures at any stage of the assessment process, and even among those who did use well-validated assessment instruments, only a few instruments were used with any regularity. These results raise some potentially troubling issues concerning the typical assessment practices of clinicians. More collaboration between researchers and clinicians is needed to improve this situation.

Perception of teasing in underweight persons: a modification of the perception of teasing scale

The psychometric properties of the Perception of Teasing Scale-Underweight, a modified version of the Perception of Teasing Scale (1), were examined. One hundred eighty-three college students (81 male; 102 female; age range 17-57 years) completed questionnaires about underweight-related and competency-related teasing experiences, eating attitudes, body image, self-esteem, and mood. Factor analysis suggested the Perception of Teasing Scale-Underweight has a two-factor structure, measuring both underweight-related and competency-related teasing experiences. Significant correlations (p<0.05) were found between the Perception of Teasing Scale-Underweight, Beck Depression Inventory, Fear of Negative Appearance Evaluation Scale, Multidimentional Body-Self Relations Questionnaire-Appearance Scales, Multiaxial Eating Disorder Scale, Social Physique Anxiety Scale, and Rosenberg Self-Esteem Scale. The pattern of correlations differed between the entire sample and those with a body mass index <21. One-way analysis of variance analyses found significant differences (p<0.05) between those with body mass index (BMI) <21 and those with BMI >21 for the weight-related event and weight-related impact scales, indicating that the measure discriminates between those individuals most likely to have been underweight as adolescents versus those most likely to have been normal weight or overweight. This measure provides a sound psychometric tool for examining underweight-related and competency-related teasing experiences. The impact of appearance and competence related teasing in underweight persons is less well understood than in overweight samples; therefore, future work should be conducted with a more underweight sample to bridge this gap in the literature.

Validity of test meals for determining binge eating

Assessment of binge eating has been criticized because of serious doubts concerning the accuracy of self-report. This experiment tested the validity of a laboratory test meal as an indicator of binge eating. Eight individuals diagnosed with binge-eating disorder (BED), eight obese non-binge-eaters, and eight normal-weight non-binge-eaters ate a test meal under conditions designed to increase the likelihood of inducing a binge episode. Non-binge-eaters, regardless of weight, felt in control of their eating and ate a relatively small amount of the test meal, while participants with BED ate significantly more food and felt significantly more out of control. Eating behavior during test meals can be a useful indicator of BED diagnostic status and may be a useful method for objectively defining binge eating.

Retrovirally delivered random cyclic Peptide libraries yield inhibitors of interleukin-4 signaling in human B cells

Inteins are polypeptide sequences found in a small set of primarily bacterial proteins that promote the splicing of flanking pre-protein sequences to generate mature protein products. Inteins can be engineered in a "split and inverted" configuration such that the protein splicing product is a cyclic polypeptide consisting of the sequence linking two intein subdomains. We have engineered a split intein into a retroviral expression system to enable the intracellular delivery of a library of random cyclic peptides in human cells. Cyclization of peptides could be detected in cell lysates using mass spectrometry. A functional genetic screen to identify 5-amino acid-long cyclic peptides that block interleukin-4 mediated IgE class switching in B cells yielded 13 peptides that selectively inhibited germ line epsilon transcription. These results demonstrate the generation of cyclic peptide libraries in human cells and the power of functional screening to rapidly identify biologically active peptides.

A confirmatory factor analysis of the cognitive capacity screening examination in a clinical sample

Structured mental status examinations offer several advantages over unstructured mental status examinations; however, few have been subjected to advanced psychometric analysis. Confirmatory factor analysis empirically tests the predictive validity of individual test indices within an a priori methodological framework. With such analysis, one can test hypotheses about the structure of latent variability within a given data set. The purpose of this study was to perform a confirmatory factor analysis of the Cognitive Capacity Screening Examination, the most comprehensive of the brief structured mental status examinations. A confirmatory factor analysis of the Cognitive Capacity Screening Examination (CCSE) was performed by applying LISREL 7 to a sample of 924 male veterans, 409 patients from a chemical dependence treatment program, and 515 individuals from a psychology consultation service. Constructs were derived from previous exploratory analysis of the scale. The results of the confirmatory factor analysis and three indices of model fit support an 11 factor model more complex than that originally formulated for the CCSE. However, three of these factors (digit span with interference, complex mental mathematics, and verbal memory) were more sensitive to impairment than other factors, accounting for over 90% of the CCSE total score variance. Although the CCSE is a more complex test than originally envisioned by its designers, it may not be necessary to give all items on the test. Either a subset of the CCSE items (the CCSE-A) or a relatively brief, informal mental status exam may be adequate for many patients.

Prospective assessment of a nomogram for the initiation of oral anticoagulation therapy for outpatient treatment of venous thromboembolism

Venous thromboembolism is a common medical problem. Recently, the emphasis has been on a switch to outpatient low molecular weight heparin therapy. Previous warfarin nomograms have been developed only for inpatients. We prospectively assessed a warfarin initiation nomogram in 105 consecutive outpatients; the nomogram requires International Normalized Ratio (INR) testing on only days 3, 5, and 8. Eighty-three percent had a therapeutic INR by day 5 and 98% by day 8. There were no major bleeds and only 6 instances of INR >4.5. This outpatient warfarin nomogram appears to be safe and efficacious in obtaining timely therapeutic levels of warfarin and deserves further study.

Detection and characterisation of swine hepatitis E virus in New Zealand

The objectives of the present study were to establish the presence of hepatitis E virus (HEV) in New Zealand pigs, first by testing for HEV antibody in pig herds throughout New Zealand to measure the herd prevalence, then by attempting to amplify HEV genomic sequences by PCR. Antibody was measured by two independently designed ELISA serology tests. HEV RNA fragments were amplified by RT-PCR of nucleic acid extracted from faeces of 10-12-week-old piglets using primers targeting ORF1, ORF2, and ORF2/3. PCR products were subject to phylogenetic analysis. Antibody to HEV was found throughout New Zealand pig herds as well as in the different age groups within the herds. Twenty herds from 22 tested were positive for HEV antibody (91% herd prevalence). Phylogenetic analysis of the amplified sequences placed this New Zealand strain of HEV closest to the human European strain It-1 (AF 110390) and U.S. swine strain (AF 082843) with 88% and 83% similarity respectively in ORF1. It was concluded that HEV is widely distributed in the New Zealand pig population. Phylogenetic analysis shows that this is a new HEV strain, grouping most closely with the United States/European cluster, which includes HEV strains of both human and swine origin.

The efficacy of cognitive-behavioral therapy on the core symptoms of bulimia nervosa

Cognitive behavioral therapy (CBT) is widely regarded as the treatment of choice for bulimia nervosa (BN), with previous reviews of the CBT outcome literature claiming an approximate 40%-50% recovery rate. Most of these reviews have focused on reductions of binge eating and purging; however, the cognitive model of BN that underlies the CBT approach identifies three additional symptoms as central to the disorder: restrictive eating, concerns with shape and weight, and self-esteem. The purpose of this review was to determine the effect of CBT on the five core symptoms of BN, particularly those neglected in previous reviews. This review found that while most studies provided outcome data on binge eating, purgative behavior, and concern with shape and weight, fewer studies provided data on restraint and self-esteem. While generally favorable, evidence for the efficacy of CBT on the core symptoms of BN was mixed, depending on the outcome measures used. Shortcomings in the literature are identified and suggestions to correct these shortcomings are provided.

A vestigial X open reading frame in duck hepatitis B virus

Duck hepatitis B virus (DHBV) appears to lack a homologue of the X protein found in mammalian hepadnaviruses. By replacing stop codons in the corresponding region of the DHBV genome, a hypothetical protein which closely matches the hydrophilicity profile of X proteins can be predicted, despite limited sequence homology. We conclude that a full-length X protein was once a common feature of the hepadnaviruses, conserved in structure but not sequence.

Stability of equilibrium states for ferroelectric smectic-C* liquid crystals in finite and infinite samples

The aim of this article is to establish some theoretical linear and nonlinear stability results for a dynamic equation that frequently appears in the smectic-C and ferroelectric smectic-C* liquid crystal literature. We consider finite planar samples confined between bounding plates as well as infinite samples. Many of the results depend on extensions of work for a nonlinear diffusion equation. Critical maximum magnitudes of applied static electric fields are determined, below which stability of a certain constant equilibrium state is ensured.

Interdisciplinary shared governance: a partnership model for high performance in a managed care environment

Today's managed care environment is forcing hospitals to seek new and innovative ways to deliver a seamless continuum of high-quality care and services to defined populations at lower costs. Many are striving to achieve this goal through the implementation of shared governance models that support point-of-service decision making, interdisciplinary partnerships, and the integration of work across clinical settings and along the service delivery continuum. The authors describe the key processes and strategies used to facilitate the design and successful implementation of an interdisciplinary shared governance model at The University Hospital, Cincinnati, Ohio. Implementation costs and initial benefits obtained over a 2-year period also are identified.

Obese women's perceptions of their physicians' weight management attitudes and practices

BACKGROUND

Obesity has reached epidemic proportions in the United States. Primary care physicians will see increasing numbers of patients with long-term weight management problems.

OBJECTIVE

To examine obese women's perceptions of their physicians' weight management attitudes and practices.

DESIGN AND SETTING

Women who participated in obesity trials at a university clinic completed a questionnaire that assessed their views of weight control provided by their primary care physician.

PARTICIPANTS

The patients were 259 women whose age was 44.0 +/- 10.0 years; weight, 96.7 +/- 13.2 kg; and body mass index (calculated as weight in kilograms divided by the square of height in meters), 35.2 +/- 4.5 (all data given as mean +/- SD).

MAIN OUTCOME MEASURES

Using 7-point scales (1 indicates low; and 7, high), patients rated their satisfaction with care provided for their general health and that for their obesity. They also identified methods their physician recommended for weight management and the frequency of negative interactions with their physician concerning weight control.

RESULTS

Participants were generally satisfied with the care they received for their general health and with their physicians' medical expertise (mean scores, 6. 1 and 6.2, respectively). They were significantly (P<.001) less satisfied with care for their obesity and with their physicians' expertise in this area (mean scores, 4.1 and 4.3, respectively). Almost 50% reported that their physician had not recommended any of 10 common weight loss methods, and 75% indicated they looked to their physician a "slight amount" or "not at all" for help with weight control. Only a small minority of patients (0.4%-8.0%) reported frequent, negative interactions with physicians concerning their weight.

CONCLUSIONS

The last finding helps allay concerns that obese patients are routinely treated disrespectfully by physicians when discussing weight. The challenge, however, for primary care physicians appears to be providing patients better assistance with weight management.

A phase II study of the 5-lipoxygenase inhibitor, CV6504, in advanced pancreatic cancer: correlation of clinical data with pharmacokinetic and pharmacodynamic endpoints

PURPOSE

Primary objective was to determine response rate of patients with advanced pancreatic cancer to a novel lipoxygenase and thromboxane A2 synthetase inhibitor (CV6504); secondary objectives included estimation of pharmacokinetics of CV6504, target-enzyme inhibition, safety and tolerance, quality of life and survival.

PATIENTS AND METHODS

Thirty-one patients with advanced pancreatic cancer were planned to receive CV6504, 100 mg TDS, orally for three months, at which point CT scans were performed to assess therapeutic response rates. Steady state concentrations of CV6504 and thromboxane B2 (an indirect measure of thromboxane A2 synthetase (TA2S) inhibition) were made. Of the 31 patients entered into the study, 23 were considered fully evaluable for response.

RESULTS

The drug was well tolerated with few side effects; no partial or complete responses were seen, but 10 patients had stable disease at 3 months; quality of life was maintained during therapy; mean CV6504 steady state plasma concentrations of 14 +/- 6 ng/ml resulting in 75 +/- 18% inhibition of TA2S were achieved; median-survival time for all patients considered eligible for assessment of efficacy was 36.6 weeks after the initial dose of study medication. The actuarial one-year survival was approximately 25%.

CONCLUSION

CV6504 inhibits its target enzyme in vivo, maintains stable disease in 32% of evaluable patients and is well tolerated.

Identification of immunodominant and conformational epitopes in the capsid protein of hepatitis E virus by using monoclonal antibodies

Antibody to the capsid (PORF2) protein of hepatitis E virus (HEV) is sufficient to confer immunity, but knowledge of B-cell epitopes in the intact capsid is limited. A panel of murine monoclonal antibodies (MAbs) was generated following immunization with recombinant ORF2.1 protein, representing the C-terminal 267 amino acids (aa) of the 660-aa capsid protein. Two MAbs reacted exclusively with the conformational ORF2.1 epitope (F. Li, J. Torresi, S. A. Locarnini, H. Zhuang, W. Zhu, X. Guo, and D. A. Anderson, J. Med. Virol. 52:289-300, 1997), while the remaining five demonstrated reactivity with epitopes in the regions aa 394 to 414, 414 to 434, and 434 to 457. The antigenic structures of both the ORF2.1 protein expressed in Escherichia coli and the virus-like particles (VLPs) expressed using the baculovirus system were examined by competitive enzyme-linked immunosorbent assays (ELISAs) using five of these MAbs and HEV patient sera. Despite the wide separation of epitopes within the primary sequence, all the MAbs demonstrated some degree of cross-inhibition with each other in ORF2. 1 and/or VLP ELISAs, suggesting a complex antigenic structure. MAbs specific for the conformational ORF2.1 epitope and a linear epitope within aa 434 to 457 blocked convalescent patient antibody reactivity against VLPs by approximately 60 and 35%, respectively, while MAbs against epitopes within aa 394 to 414 and 414 to 434 were unable to block patient serum reactivity. These results suggest that sequences spanning aa 394 to 457 of the capsid protein participate in the formation of strongly immunodominant epitopes on the surface of HEV particles which may be important in immunity to HEV infection.

The perceived relative worth of reaching and maintaining goal weight

OBJECTIVE

To examine the perceived relative worth of reaching and maintaining a self-selected goal weight, for obese and non-obese individuals.

DESIGN

Cross-sectional study.

SUBJECTS

Twenty-five obese treatment-seekers (age 41.0 y, BMI 42.5) and a community sample of 31 obese (age 40.8 y, BMI 32.2) and 64 non-obese participants (age 32.4 y, BMI 23.4).

MEASUREMENT

An 18-item forced-choice questionnaire evaluating what participants would hypothetically sacrifice to reach and maintain their goal weight.

RESULTS

Most obese treatment-seekers would hypothetically endure much to achieve their desired weight. For example, 88% or more would forego a job promotion, retiring with full-pay, eliminating the national debt, or winning their dream house or car or an all-expense-paid vacation, and smaller majorities would suffer loss of half their income or a job demotion. Many non-treatment-seeking obese would forfeit future rewards to reach goal weight, but fewer would incur negative events. About a third of non-obese participants would forgo certain positive events, but few would suffer an adverse event to achieve goal weight. Within the combined obese sample, females viewed attaining goal weight as more important than did males, but there were no significant racial differences. An index of overall worth of weight goal was related positively to current weight and BMI and negatively to goal weight as percentage of current weight (P<0.01).

CONCLUSION

Excessive value may be placed on attaining less than realistic weight goals, particularly but not exclusively by treatment-seeking and heavier obese people and those who desire greater weight loss. Clinicians should take this phenomenon into consideration, and public health initiatives should attempt to place body weight in a more balanced perspective.

Infection of polarized cultures of human intestinal epithelial cells with hepatitis A virus: vectorial release of progeny virions through apical cellular membranes

Although hepatitis A virus (HAV) is typically transmitted by the fecal-oral route, little is known of its interactions with cells of the gastrointestinal tract. We studied the replication of HAV in polarized cultures of Caco-2 cells, a human cell line which retains many differentiated functions of small intestinal epithelial cells. Virus uptake was 30- to 40-fold more efficient when the inoculum was placed on the apical rather than the basolateral surface of these cells, suggesting a greater abundance of the cellular receptor for HAV on the apical surface. Infection proceeded without cytopathic effect and did not influence transepithelial resistance or the diffusion of inulin across cell monolayers. Nonetheless, there was extensive release of progeny virus, which occurred almost exclusively into apical supernatant fluids (36.4% +/- 12.5% of the total virus yield compared with 0.23% +/- 0.13% release into basolateral fluids). Brefeldin A caused a profound inhibition of HAV replication, but also selectively reduced apical release of virus. These results indicate that polarized human epithelial cell cultures undergo vectorial infection with HAV and that virus release is largely restricted to the apical membrane. Virus release occurs in the absence of cytopathic effect and may involve cellular vesicular transport mechanisms.

Core protein phosphorylation modulates pregenomic RNA encapsidation to different extents in human and duck hepatitis B viruses

To clarify the role of core protein phosphorylation in pregenomic-RNA encapsidation of human and duck hepatitis B viruses (HBV and DHBV, respectively), we have examined the phosphorylation states of different forms of intracellular HBV core protein and the phenotypic effects of mutations in the phosphorylation sites of HBV and DHBV core proteins. We show that HBV core protein is phosphorylated to similar extents in the form of protein dimers and after further assembly in pregenomic RNA-containing capsids. Individual and multiple substitutions of alanine and aspartic acid for serine in the phosphorylation sites of HBV core protein resulted in site-specific and synergistic effects on RNA encapsidation, ranging from 2-fold enhancement to more than 10-fold inhibition. Core protein variants with mutations in all phosphorylation sites exhibited dominant-negative effects on RNA encapsidation by wild-type protein. The results suggest that the presence of phosphoserine at position 162 of HBV core protein is required for pregenomic-RNA encapsidation, whereas phosphoserine at position 170 optimizes the process and serine might be preferable in position 155. Examination of the pregenomic-RNA-encapsidating capacities of DHBV core protein variants, in which four phosphorylation sites were jointly mutated to alanine or aspartic acid, suggests that phosphorylation of DHBV core protein at these sites may optimize pregenomic-RNA encapsidation but that its impact is much less profound than in the case of HBV. The possible mechanisms by which RNA encapsidation may be modulated by core protein phosphorylation are discussed in the context of the observed differences between the two viruses.

Recombinant subunit ORF2.1 antigen and induction of antibody against immunodominant epitopes in the hepatitis E virus capsid protein

A recombinant subunit antigen (ORF2.1), representing the carboxy-terminal 267 amino acids of the 660-amino-acid hepatitis E virus (HEV) capsid protein, was expressed in Escherichia coli and used for the immunisation of rats. Purified antigen formulated with either Aluminium Hydroxide Gel Adjuvant (Alum) or Titermax gave high and equivalent levels of antibody after three doses. Responses to two doses of 15, 75, or 150 microg antigen, formulated with Alum and given at 0 and 4 weeks, were also equivalent by 17 weeks after immunisation. Rats initially developed antibody to a wide range of linear epitopes in the ORF2.1 region, but by 27 weeks the predominant response detected by Western immunoblotting was restricted to the conformational epitope unique to ORF2.1 [Li et al. (1997) Journal of Medical Virology 52:289-300], a pattern that was also observed when comparing acute-phase patient serum samples with serum samples from convalescing patients. Antibody from immunised rats blocked the majority of patients' serum reactivity in enzyme-linked immunosorbent assay against both ORF2.1 (57-92% inhibition) and virus-like particles of HEV produced using the baculovirus system (74-97% inhibition). Together, these results suggest that the ORF2.1 subunit vaccine induces an antibody response against immunodominant, conformational epitopes in the viral capsid, which largely mimics that seen in convalescent patients, who are presumed to be immune to HEV infection.

Uncoating kinetics of hepatitis A virus virions and provirions

When the growth kinetics of immature hepatitis A virus provirions and mature virions were monitored, distinct eclipse phases were noted for both types of particles. Strikingly, uncoating of virions occurred around 4 h postinfection, while uncoating of provirions occurred predominantly between 8 and 10 h postinfection. It is proposed that the heterogeneous mixture of infectious hepatitis A virus particles (virions and provirions) typically present in inocula is responsible for the normally asynchronous nature of hepatitis A virus uncoating kinetics.

Recombinant subunit ORF2.1 antigen and induction of antibody against immunodominant epitopes in the hepatitis E virus capsid protein

A recombinant subunit antigen (ORF2.1), representing the carboxy-terminal 267 amino acids of the 660-amino-acid hepatitis E virus (HEV) capsid protein, was expressed in Escherichia coli and used for the immunisation of rats. Purified antigen formulated with either Aluminium Hydroxide Gel Adjuvant (Alum) or Titermax gave high and equivalent levels of antibody after three doses. Responses to two doses of 15, 75, or 150 microg antigen, formulated with Alum and given at 0 and 4 weeks, were also equivalent by 17 weeks after immunisation. Rats initially developed antibody to a wide range of linear epitopes in the ORF2.1 region, but by 27 weeks the predominant response detected by Western immunoblotting was restricted to the conformational epitope unique to ORF2.1 [Li et al. (1997) Journal of Medical Virology 52:289-300], a pattern that was also observed when comparing acute-phase patient serum samples with serum samples from convalescing patients. Antibody from immunised rats blocked the majority of patients' serum reactivity in enzyme-linked immunosorbent assay against both ORF2.1 (57-92% inhibition) and virus-like particles of HEV produced using the baculovirus system (74-97% inhibition). Together, these results suggest that the ORF2.1 subunit vaccine induces an antibody response against immunodominant, conformational epitopes in the viral capsid, which largely mimics that seen in convalescent patients, who are presumed to be immune to HEV infection.

The explosive human immunodeficiency virus type 1 epidemic among injecting drug users of Kathmandu, Nepal, is caused by a subtype C virus of restricted genetic diversity

An explosive epidemic of human immunodeficiency virus type 1 (HIV-1) has been documented among the injecting drug user population of Kathmandu, Nepal, whose seropositivity rate has risen from 0 to 40% between 1995 and 1997. By using Catrimox to preserve whole-blood RNA at ambient temperature for transportation, HIV-1 envelope V3-V4 sequences were obtained from 36 patients in this group. Analysis of the sequences indicated a homogenous epidemic of subtype C virus, with at least two independent introductions of the virus into the population. Viral diversity was restricted within two transmission subclusters, with the majority of variation occurring in V4. Calculation of the synonymous-to-nonsynonymous mutation ratio (Ks:Ka) across this region showed that significant evolutionary pressure had been experienced during the rapid horizontal spread of the virus in this population, most strongly directed to the region between V3 and V4.

Seroprevalence of antibodies to hepatitis E virus in the normal blood donor population and two aboriginal communities in Malaysia

The prevalence of antibodies to hepatitis E virus (HEV) has been examined in many countries, but such studies have generally been limited to majority populations such as those represented in healthy blood donors or cross sections of urban populations. Due to its major route of enteric transmission, large differences in HEV prevalence might be expected between populations in the same country but with different living conditions. Using an ELISA based on GST-ORF2.1 antigen, the prevalence of IgG-class antibodies to HEV was examined in three distinct populations in Malaysia: the normal (urban) blood donor population and two aboriginal communities located at Betau, Pahang and Parit Tanjung, Perak. IgG anti-HEV was detected in 45 (44%) of 102 samples from Betau and 15 (50%) of 30 samples from Parit Tanjung, compared to only 2 (2%) of 100 normal blood donors. The distribution of sample ELISA reactivities was also consistent with ongoing sporadic infection in the aboriginal communities, while there was no significant relationship between HEV exposure and age, sex, or malaria infection. The high prevalence of antibodies to HEV in the two aboriginal communities indicates that this group of people are at high risk of exposure to HEV compared to the general blood donors, and the results suggest that studies of HEV seroprevalence within countries must take into account the possibility of widely varying infection rates between populations with marked differences in living conditions.

Serological evidence for swine hepatitis E virus infection in Australian pig herds

Hepatitis E virus (HEV) is an enterically transmitted human pathogen, with some similarities to caliciviruses. A variant of HEV was recently identified in pigs in the USA, infecting almost 100% of animals in commercial herds. Phylogenetic analysis suggests that this is a true 'swine HEV' distinct from the human virus, but the swine virus may also infect man. Using an in-house ELISA based on a highly conserved, recombinant HEV protein, we have examined collections of sera from Australian pigs for evidence of HEV infection in local pig herds. Sera from one research herd (n = 32) were uniformly non-reactive, and this was used to establish an assay cut-off (= mean + 3 SD of reference pig serum reactivities). Screening of sera from other herds demonstrates that swine HEV is present in Australia, with reactivity observed in 30% (12/40) of random samples from two piggeries, 92-95% of pigs by the age of 16 weeks in two other piggeries (n = 45), and 17% (15/59) of wild-caught pigs. Further studies are required to examine whether HEV causes disease in pigs and to determine the risk of swine HEV transmission to man.

ELISA for IgG-class antibody to hepatitis E virus based on a highly conserved, conformational epitope expressed in Escherichia coli

In assays based on most recombinant hepatitis E virus (HEV) antigens, the IgG antibody responses to HEV are observed commonly to wane or disappear after the acute phase of infection. Such IgG assays have therefore been used for the diagnosis of acute HEV infection, but they have limited usefulness in seroepidemiological studies. Using western immunoblotting, it was shown previously that the open reading frame (ORF) 2.1 antigen, representing the carboxy-terminal 267 amino acids (aa) of the capsid protein, exposes a conformational epitope which allows optimal detection of convalescent antibody compared to other proteins expressed in Escherichia coli. This conformational epitope is shown to be highly conserved between divergent human HEV isolates, and the development of a sensitive and highly specific enzyme immunoassay (ELISA) based on this recombinant antigen is described. The ORF2.1 ELISA allows the detection and quantitation of both acute- and convalescent phase HEV-specific IgG, and will help to define better the antibody responses to the virus and the prevalence of HEV infection worldwide.

Only the non-glycosylated fraction of hepatitis E virus capsid (open reading frame 2) protein is stable in mammalian cells

Hepatitis E virus (HEV) is a non-enveloped, positive-strand RNA virus, with the genome encoding three open reading frames (ORFs) of which ORF 2 directs translation of the capsid protein, PORF2. Following pulse-labelling and cell fractionation of PORF2 expressed in mammalian cells using the Semliki Forest virus replicon, the capsid protein was detected as three major species of 78 (PORF2), 82 and 86 kDa, with P82 and P86 being N-glycosylated (gPORF2 and ggPORF2, respectively). Although gPORF2 and ggPORF2 species represented 79% of total PORF2 after 20 min metabolic labelling and were largely membrane-associated, the glycosylated PORF2 species were much less stable than non-glycosylated PORF2, which was present in the cytosol and represented the major product accumulated in the cell. In the absence of detectable surface expression or export of PORF2, this suggests that glycosylated ORF 2 proteins may not be intermediates in HEV capsid assembly.

Conceptualizing and measuring integration: findings from the health systems integration study

Given the pressures for health care reform, interest in the concept of integrated or organized delivery systems as a means to offer more coordinated cost-effective care is growing. This article has two primary objectives: (1) to clarify the different types of integration associated with the notion of an organized delivery system, and (2) to share the results from an ongoing study of 12 organized delivery systems. The findings indicate a moderate level of integration overall, particularly in the areas of culture, financial planning, and strategic planning. The study found that corporate staff respondents perceive their systems to be more integrated and effective than do operating unit managers, and that some functional integration areas are positively associated with both physician-system and clinical integration that, in turn, are positively related to each other. Overall, perceived integration was found to be positively associated with perceived effectiveness.

Creating organized delivery systems: the barriers and facilitators

An organized delivery system is a network of organizations that provides or arranges to provide a coordinated continuum of services to a defined population and is willing to be held clinically and fiscally accountable for the outcomes and the health status of the population served. As such, organized delivery systems are at the center of efforts to implement health care reform. Based on analysis of 12 such systems, this article identifies key characteristics that influence what organized delivery systems are able to do, outlines the major obstacles or challenges to achieving greater levels of integration, and then discusses a number of approaches for effectively dealing with these obstacles.

Treating the obese patient. Suggestions for primary care practice

Obesity is a major health problem in America. Weight loss is associated with improvements in obesity-related health complications, but patients and practitioners are frequently disappointed by the long-term results of weight control efforts. Recent research has yielded new findings concerning the causes of obesity, as well as new goals for obesity treatment. Traditionally, the goal of therapy has been reduction to ideal weight. Several scientific bodies, however, now recommend a more modest 5% to 15% reduction in initial weight. Current options for weight loss include behavioral or pharmacological management provided during primary care visits, self-help and commercial programs, hospital-based interventions, and bariatric surgery. Regardless of the approach selected, long-term care usually is required to facilitate the maintenance of weight loss.