Clinically relevant orthotopic pancreatic cancer models for adoptive T cell transfer therapy

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive tumor. Prognosis is poor and survival is low in patients diagnosed with this disease, with a survival rate of ~12% at 5 years. Immunotherapy, including adoptive T cell transfer therapy, has not impacted the outcomes in patients with PDAC, due in part to the hostile tumor microenvironment (TME) which limits T cell trafficking and persistence. We posit that murine models serve as useful tools to study the fate of T cell therapy. Currently, genetically engineered mouse models (GEMMs) for PDAC are considered a "gold-standard" as they recapitulate many aspects of human disease. However, these models have limitations, including marked tumor variability across individual mice and the cost of colony maintenance.

METHODS

Using flow cytometry and immunohistochemistry, we characterized the immunological features and trafficking patterns of adoptively transferred T cells in orthotopic PDAC (C57BL/6) models using two mouse cell lines, KPC-Luc and MT-5, isolated from C57BL/6 KPC-GEMM (KrasLSL-G12D/+p53-/- and KrasLSL-G12D/+p53LSL-R172H/+, respectively).

RESULTS

The MT-5 orthotopic model best recapitulates the cellular and stromal features of the TME in the PDAC GEMM. In contrast, far more host immune cells infiltrate the KPC-Luc tumors, which have less stroma, although CD4+ and CD8+ T cells were similarly detected in the MT-5 tumors compared with KPC-GEMM in mice. Interestingly, we found that chimeric antigen receptor (CAR) T cells redirected to recognize mesothelin on these tumors that signal via CD3ζ and 41BB (Meso-41BBζ-CAR T cells) infiltrated the tumors of mice bearing stroma-devoid KPC-Luc orthotopic tumors, but not MT-5 tumors.

CONCLUSIONS

Our data establish for the first time a reproducible and realistic clinical system useful for modeling stroma-rich and stroma-devoid PDAC tumors. These models shall serve an indepth study of how to overcome barriers that limit antitumor activity of adoptively transferred T cells.

Risk of post-acute sequelae of SARS-CoV-2 infection associated with pre-coronavirus disease obstructive sleep apnea diagnoses: an electronic health record-based analysis from the RECOVER initiative

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) has been associated with more severe acute coronavirus disease-2019 (COVID-19) outcomes. We assessed OSA as a potential risk factor for Post-Acute Sequelae of SARS-CoV-2 (PASC).

METHODS

We assessed the impact of preexisting OSA on the risk for probable PASC in adults and children using electronic health record data from multiple research networks. Three research networks within the REsearching COVID to Enhance Recovery initiative (PCORnet Adult, PCORnet Pediatric, and the National COVID Cohort Collaborative [N3C]) employed a harmonized analytic approach to examine the risk of probable PASC in COVID-19-positive patients with and without a diagnosis of OSA prior to pandemic onset. Unadjusted odds ratios (ORs) were calculated as well as ORs adjusted for age group, sex, race/ethnicity, hospitalization status, obesity, and preexisting comorbidities.

RESULTS

Across networks, the unadjusted OR for probable PASC associated with a preexisting OSA diagnosis in adults and children ranged from 1.41 to 3.93. Adjusted analyses found an attenuated association that remained significant among adults only. Multiple sensitivity analyses with expanded inclusion criteria and covariates yielded results consistent with the primary analysis.

CONCLUSIONS

Adults with preexisting OSA were found to have significantly elevated odds of probable PASC. This finding was consistent across data sources, approaches for identifying COVID-19-positive patients, and definitions of PASC. Patients with OSA may be at elevated risk for PASC after SARS-CoV-2 infection and should be monitored for post-acute sequelae.

FaStaNMF: a Fast and Stable Non-negative Matrix Factorization for Gene Expression

Gene expression analysis of samples with mixed cell types only provides limited insight to the characteristics of specific tissues. In silico deconvolution can be applied to extract cell type specific expression, thus avoiding prohibitively expensive techniques such as cell sorting or single-cell sequencing. Non-negative matrix factorization (NMF) is a deconvolution method shown to be useful for gene expression data, in part due to its constraint of non-negativity. Unlike other methods, NMF provides the capability to deconvolve without prior knowledge of the components of the model. However, NMF is not guaranteed to provide a globally unique solution. In this work, we present FaStaNMF, a method that balances achieving global stability of the NMF results, which is essential for inter-experiment and inter-lab reproducibility, with accuracy and speed. Results: FaStaNMF was applied to four datasets with known ground truth, created based on publicly available data or by using our simulation infrastructure, RNAGinesis. We assessed FaStaNMF on three criteria - speed, accuracy, and stability, and it favorably compared to the standard approach of achieving reproduceable results with NMF. We expect that FaStaNMF can be applied successfully to a wide array of biological data, such as different tumor/immune and other disease microenvironments.

Effect of SARS-CoV-2 Infection and Infection Severity on Longer-Term Glycemic Control and Weight in People With Type 2 Diabetes

OBJECTIVE

To evaluate the association of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severity of infection with longer-term glycemic control and weight in people with type 2 diabetes (T2D) in the U.S.

RESEARCH DESIGN AND METHODS

We conducted a retrospective cohort study using longitudinal electronic health record data of patients with SARS-CoV-2 infection from the National COVID Cohort Collaborative (N3C). Patients were ≥18 years old with an ICD-10 diagnosis of T2D and at least one HbA1c and weight measurement prior to and after an index date of their first coronavirus disease 2019 (COVID-19) diagnosis or negative SARS-CoV-2 test. We used propensity scores to identify a matched cohort balanced on demographic characteristics, comorbidities, and medications used to treat diabetes. The primary outcome was the postindex average HbA1c and postindex average weight over a 1 year time period beginning 90 days after the index date among patients who did and did not have SARS-CoV-2 infection. Secondary outcomes were postindex average HbA1c and weight in patients who required hospitalization or mechanical ventilation.

RESULTS

There was no significant difference in the postindex average HbA1c or weight in patients who had SARS-CoV-2 infection compared with control subjects. Mechanical ventilation was associated with a decrease in average HbA1c after COVID-19.

CONCLUSIONS

In a multicenter cohort of patients in the U.S. with preexisting T2D, there was no significant change in longer-term average HbA1c or weight among patients who had COVID-19. Mechanical ventilation was associated with a decrease in HbA1c after COVID-19.

Influence of thermal stimulation during the late phase of incubation on hatching results and post-hatch broiler performance under commercial conditions

Two experiments, which differed in breeder age, strain and season, were conducted to study the influence of low-intensity, short-duration thermal stimuli during the late phase of incubation on hatchability and performance. The first experiment conducted in April-June used eggs from Cobb × Ross broiler breeders at 35-41 weeks of age and the second experiment performed in February-April used eggs from Hubbard × Cobb broiler breeders at 49-53 weeks of age. Eggs in the test group had the same physical environment as eggs in the control group except that incubation temperature was increased by 1˚C for 2 h/d above the control group from 18 to 20 d of incubation (DI). The results demonstrated that thermal stimulation of 1˚C for 2 h/d above control incubation temperature during 18-21DI did not have any adverse effects on hatch and post-hatch performance of broilers. In both experiments, treatment did not significantly alter the secondary sex ratio in hatched chickens, but hatch residue showed that the proportion of unhatched male embryos was significantly lower in the test groups than in the control groups. In the first experiment, thermal stimulation improved feed conversion by 1.82% compared with the control.

IN VITRO CHEMOTHERAPY PROFILING OF WELL-DIFFERENTIATED MIDGUT NEUROENDOCRINE TUMORS (NETS) BASED ON INDIVIDUAL PATIENT TUMOR BIOMARKERS ANALYSIS

BACKGROUND

Midgut neuroendocrine tumors (NETs) are rare malignancies with indolent clinical courses. In general, they are well-differentiated with most tumor cells in the G0 phase of the cell cycle, consistent with the poor response rate of NETs to chemotherapy in vivo. We hypothesize that insults, such as surgery, can drive NET cells from G0 into S phase and that biomarker analysis of individual patient tumors harvested and grown in the lab will provide useful practical guide for future intra and post-operative adjuvant therapy.

METHODS

97 well-differentiated midgut NET patients underwent cytoreductive surgery at our institution between May/2012 and October/2012. 148 surgical specimens were collected and submitted to a single commercial lab for processing. Primary tumors, lymph nodes and liver metastases were harvested and cultured. Their ribonucleic acids (RNA) were then extracted to analyze the expressivity, a total of 88 different biomarkers. Based on our patients' specific tumor biomarker expressivity and known correlations between 36 anti-neoplastic agents with their linked biomarkers, recommendations were reported as clinically beneficial or non-beneficial.

RESULTS

A total of 148 specimens from 97 patients were tested. In four of the 97 patients, no clinically beneficial chemotherapy agent could be identified. Among the remaining 93 patients, the top three agents that are most likely to be clinically beneficial are: fluorouracil, cisplatin and carboplatin. These were reported to be clinically beneficial in 135/148 (91.2%), 103/148 (69.6%), and 103/148 (69.6%) patients respectively.

CONCLUSIONS

Midgut NETs are slow growing tumors which are chemotherapeutically inert owing to the fact that most of the tumor cells are in G0 cell cycle. Surgical insult drives NET cells into active synthetic phase where they begin to express biomarkers specific to their tumor cells. Analysis of these biomarkers guides further potential beneficial therapy based on the current known associations among biomarkers and chemotherapy agents. These results must then be compared and confirmed against a direct in-vitro chemo sensitivity assessment conducted simultaneously on the same patients.

Advanced neonatal nurse practitioners in the workforce: a review of the evidence to date

The last decade has seen dramatic changes in the working arrangements and training requirements of junior medical staff employed in neonatal units. As a result, there is a need for the professional roles in service provision to be reappraised. In many neonatal services, advanced neonatal nurse practitioners (ANNPs) have been introduced and have been shown to be effective in providing an alternative option for the provision of neonatal care at both junior and middle-grade medical staffing level. One of the key factors of the success of this role is the underpinning years spent in clinical practice, a foundation that provides a valuable and unique perspective for professional functioning at a senior level. For this potential to be fully exploited, a more integrated approach to the development of career pathways for ANNPs is needed. However, there are challenges related to recruitment, and the relatively small numbers of ANNPs available means that they are unlikely to provide an immediate solution for many units. The introduction of physicians' assistants (PAs) would seem to be worthy of consideration as part of the neonatal workforce, but it is likely that their functioning will be best integrated with that of ANNPs. In the longer term, economic factors will be a powerful determinant of the relative proportion of consultants, trainee doctors, ANNPs and PAs in the workforce.

Reduced telomere length in rheumatoid arthritis is independent of disease activity and duration

BACKGROUND

Rheumatoid arthritis (RA) is associated with reduced lifespan and shortened telomere length in lymphocytes, but the mechanism underlying this is unclear. Telomere loss in white blood cells (WBC) is accelerated by oxidative stress and inflammation in vitro. It was postulated that the accelerated WBC telomere shortening in RA occurs as a result of exposure to chronic inflammation.

OBJECTIVES

To measure telomere terminal restriction fragment (TRF) length in a large cohort of RA cases and healthy controls, to explore associations of TRF length with features of disease and with RA-associated HLA-DRB1 alleles.

METHODS

WBC and TRF length were measured by Southern blot in DNA from 176 hospital-based RA cases satisfying the 1987 American College of Rheumatology criteria and from 1151 controls. TRF length was compared between cases and controls, and the effects of disease duration, severity and HLA-DRB1 alleles encoding the shared epitope (SE) were assessed.

RESULTS

Age- and sex-adjusted TRF length was significantly shorter in RA cases compared with controls (p<0.001). There was no association between age- and sex-adjusted TRF length and disease duration, C reactive protein or Larsen score. The presence of one or more SE-encoding alleles was associated with reduced adjusted TRF length in RA cases (SE positive vs SE negative cases, p=0.038), but not in controls.

CONCLUSION

The reduced TRF length in a large group of patients with RA compared with controls has been shown. The reduction is apparently independent of disease duration and markers of disease severity, but is influenced by HLA-DRB1 genotype.

Effects of packaging atmospheres on shelf-life quality of ground ostrich meat

Fresh ground ostrich meat was packaged under high oxygen (O2), high nitrogen (N2), vacuum (VAC) and ambient air (AIR) atmospheres, stored at 4±1°C and displayed under 1700±100lux of fluorescent lighting for 9 days. The meat was evaluated for changes in typical shelf-life characteristics consisting of pH, color properties (CIE L(∗), a(∗), b(∗), and total color difference, ΔE), oxidative changes (thiobarbituric acid value and hexanal content) and bacterial counts (total viable cell, coliform, lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp.) Initial meat pH was 6.16 and declined slightly during storage. TBA values and hexanal content were highest in O2 and lowest (P⩽0.05) in VAC and N2 atmospheres. Surface lightness (L(∗)) and redness (a(∗)) were highest in O2 packaging initially, decreasing (P⩽0.05) by day 9. ΔE of the ground ostrich increased during storage in only O(2) and AIR packaging. All packaging methods had generally similar effects on microbial outgrowth. Total aerobic bacteria attained >10(6) CFU/g meat between day 3 and day 6. Ground ostrich meat was below saleable quality in less than 6 days based on all of the meat attributes. For O2 packaging however, quality based on lipid oxidation and color properties indicated a shelf-life of less than 3 days. Oxidation is likely the limiting factor for shelf-life of ground ostrich meat.

The ethics of managed care: a dose of realism

This article examines the ethics of medical practice under managed care from a pragmatic perspective that gives physicians more useful guidance than existing ethical statements. The article begins by stating the authors' starting premises and framework for constructing a realistic set of ethical principles: namely, that bedside rationing in some form is permissible; that medical ethics derive from physicians' role as healers; that actual agreements usually trump hypothetical ones; that ethical statements are primarily aspirational, not regulatory; and that preserving patient trust is the primary objective. The authors then articulate the following concrete ethical guides: financial incentives should influence physicians to maximize the health of the group of patients under their care; physicians should not enter into incentive arrangements that they would be embarrassed to describe accurately to their patients or that are not in common use in the market; physicians should treat each patient impartially, without regard to source of payment, and in a manner consistent with the physician's own treatment style; if physicians depart from this ideal, they must tell their patients honestly; and it is desirable, although not mandatory, to differentiate medical treatment recommendations from insurance coverage decisions by clearly assigning authority over these different roles and by having physicians to advocate for recommended treatment that is not covered.

Nucleoside diphosphate kinase is a possible component of the ethylene signal transduction pathway

In etiolated seedlings of Pisum sativum and leaves of Arabidopsis thaliana, in vivo ethylene treatment resulted in an increase in in vitro phosphorylation of 17 kD (P. sativum) or 16 and 17 kD (A. thaliana) polypeptides. These polypeptides were identified as nucleoside diphosphate kinase (NDPK) based on both biochemical properties and interaction with antibodies against NDPK from P. sativum. Using the receptor-directed antagonist of ethylene action 2,5-norbornadiene and the ethylene-insensitive mutants of A. thaliana etr1-1 and eti5, ethylene specificity and receptor dependence of NDPK phosphorylation have been demonstrated. In pea epicotyls, ethylene treatment also led to increase in nucleoside transferase activity unlike in A. thaliana leaves. The increases in nucleoside transferase activity and NDPK phosphorylation were very rapid and transient. The results suggest a role for NDPK as a possible component of the ethylene signal transduction chain.

Developing a neonatal workforce: role evolution and retention of advanced neonatal nurse practitioners

BACKGROUND

Over the past decade more than 120 advanced neonatal nurse practitioners (ANNPs) have graduated from the Southampton based ANNP programme.

OBJECTIVES

To determine the scope of practice and evolving role of ANNPs and to identify factors that may affect future recruitment and retention.

METHOD

An open ended structured questionnaire on clinical role, working arrangements, retention and attrition, continuing education, and professional development was sent to 95 ANNPs.

RESULTS

A response rate of 83% was achieved. There was an attrition rate of 14%, with most ANNPs remaining in their original seconding unit. Factors considered to be important for role satisfaction included a well defined role, working within a team of ANNPs, appropriate remuneration, and evidence of unit support for both role definition and continuing professional development.

CONCLUSIONS

Although ANNPs are expensive to both train and employ, this evidence suggests that there is a good return on the investment in terms of retention to the unit and the specialty. Their role incorporates many features of advanced nursing practice as well as providing "value added" neonatal care by merging traditional medical and nursing roles and crossing professional boundaries. In 2004 the manpower challenges for neonatal units will be even more acute; these data confirm that there are effective options available but they require long term strategic planning and investment.

Legal rules and industry norms: the impact of laws restricting health insurers' use of genetic information

Since 1991, twenty-eight states have enacted laws that prohibit insurers' use of genetic information in pricing, issuing, or structuring health insurance. This article evaluates whether these laws reduce the extent of genetic discrimination by health insurers. Using multiple data sources, it concludes that there are almost no well-documented cases of health insurers asking for or using pre-symptomatic genetic test results in their underwriting decisions either before or after these laws, or in states with or without these laws. At present, health insurers are not thinking about or interested in using genetic information of this sort. Using this information is not cost effective and is not seen as contributing significantly to underwriting accuracy. However, if genetic testing information were easily available, some health insurers would consider using it in some fashion if that were legal. In the future, such information could become much more relevant to health insurers than it is now. Therefore, the major effect of these laws is to make it less likely that insurers will use genetic information in the future. Although insurers and agents are only vaguely aware of these laws, the laws have helped to convince the industry that it is not appropriate or socially legitimate to use this information. Thus, these laws have caused the insurance industry to embrace more socially oriented norms and attitudes.

Premature ovarian failure in women with juvenile idiopathic arthritis (JIA)

OBJECTIVE

To examine the effect of longstanding juvenile idiopathic arthritis (JIA) on menstrual irregularity and the incidence of premature ovarian failure in women.

METHODS

Women with longstanding JIA who had abnormal or absent menstrual cycles had their circulating levels of gonadotrophins measured to check for the presence of ovarian failure. Disease demographics and subsets, function, age at onset of menstrual irregularity, previous medical intervention, concurrent diseases and history of pregnancy/delivery were documented.

RESULTS

177/187 (95%) of female adults with JIA who were identified and contacted, participated in the study. The average age at review was 35.4 years (19-78) with average disease duration of 28.7 years. 47.4% of all patients had clinically active arthritis. 44.6% of all patients had severe disability (HAQ score > 1.5). Six patients had premature ovarian failure unrelated to medication use, comprising 3.4% of the females in the study, compared to an expected incidence of 1% in the general population (p < 0.01). In addition, three (1.7%) of these had onset of symptoms before age 30, compared to an expected incidence of 0.1% in the general population (p < 0.01). The average maternal age at first delivery in women with JIA (27.2 years) was higher than the general population (23.5 years).

CONCLUSION

Idiopathic premature ovarian failure was more commonly found in individuals with juvenile idiopathic arthritis. In addition a small number of patients had iatrogenic premature ovarian failure related to chlorambucil use.

Long-term follow-up of 246 adults with juvenile idiopathic arthritis: predictive factors for mood and pain

OBJECTIVE

To examine the predictive factors for anxiety, depression and pain in adults with juvenile idiopathic arthritis (JIA).

PATIENTS AND METHODS

Two hundred and forty-six adults identified with long-standing JIA had an average disease duration of 28.3 yr. Candidate factors potentially predictive for pain, anxiety and depression were assessed by multiple regression analysis.

RESULTS

Of the patients, 31.6% were anxious, 5.2% were depressed, and 21.1% had previously suffered from depression. The percentage of the variance accounted for by other variables was 78.8 for anxiety variance and 54.5 for depression, but there was little influence from physical disease-related factors. Severe pain, measured on a visual analogue scale, occurred in 32.9% of patients, and 22.8% had poor perceived control over their pain. Function, coping strategies, pain self-efficacy, inflammation and previous depression could predict 39.6% of the variance in pain.

CONCLUSIONS

Comparing adults with children, disease activity and control over pain remain predictors of pain but become less important than disability and coping strategies.

Long-term follow-up of 246 adults with juvenile idiopathic arthritis: social function, relationships and sexual activity

OBJECTIVE

To examine social function, relationships and sexual activity in adults with juvenile idiopathic arthritis (JIA).

PATIENTS AND METHODS

Two hundred and forty-six adults identified with long-standing JIA had an average disease duration of 28.3 yr. Specific information was sought on marital status, offspring, age at first sexual encounter, and problems related to disease in sexual activity and pregnancy.

RESULTS

Fewer patients (42.8%) were in stable relationships than their siblings (55.3%). The percentage of patients with children was 27.5. Twenty-three per cent of all known pregnancies ended in miscarriage. Of the women who had had a Caesarean, 78.9% had either reduced hip mobility or short stature. JIA had a detrimental effect on body image in 50.7% of patients but relationships were affected in only 28.2%. The percentage of patients who were sexually active or had had previous sexual experience was 83.3; 58.3% of these had disease-related sexual problems.

CONCLUSIONS

A significant proportion of individuals are sexually active before transfer to adult rheumatology care at the age of 18 yr. This highlights the need to introduce sexual counselling in adolescent clinics. The high incidence of psychological sexual problems may benefit from appropriate counselling and training.

Long-term follow-up of 246 adults with juvenile idiopathic arthritis: education and employment

OBJECTIVE

To examine the levels of education and employment in adults with juvenile idiopathic arthritis (JIA) compared with their siblings and national figures.

PATIENTS AND METHODS

Two hundred and forty-six adults identified with long-standing JIA had an average disease duration of 28.3 yr. Educational achievements and employment status were recorded and comparative data obtained from siblings and the National Office for Statistics, UK. The effects, incidence and nature of discrimination in the workplace were also explored.

RESULTS

Across all levels of education the study group achieved significantly better results than both the national average and their siblings. In contrast, the rate of unemployment in the patient group was more than twice that in the national population. The percentage of patients who had encountered discrimination in the workplace was 25.1.

Long-term follow-up of 246 adults with juvenile idiopathic arthritis: functional outcome

OBJECTIVE

To examine the clinical and functional outcome of adults with juvenile idiopathic arthritis (JIA) using the recent World Health Organization/International League Against Rheumatism (ILAR) classification.

PATIENTS AND METHODS

Two hundred and fifty-nine adults with long-standing JIA (average disease duration 28.3 yr) were eligible for the study; 246 (95%) attended for an interview, clinical examination and notes review and 231 (89.2%) returned a comprehensive functional and psychosocial self-assessment questionnaire.

RESULTS

Of all patients, 43.3% had active arthritis clinically and 54.4% on laboratory measures (C-reactive protein). Clinical inflammation was less common in systemic-onset JIA. The percentage of all patients with severe disability (Health Assessment Questionnaire score >1.5) was 42.9. Uveitis occurred frequently in the oligoarticular-onset and enthesitis-related subsets. Over 30% of the extended oligoarticular group with uveitis developed glaucoma compared with none of the enthesitis group.

CONCLUSIONS

Adults with JIA often have significant levels of disability, often related to continuing active disease over prolonged periods. There is a clear need for good transition from paediatric to high-quality adult rheumatology care.

Long-term follow-up of 246 adults with juvenile idiopathic arthritis: predictive factors for mood and pain

OBJECTIVE

To examine the predictive factors for anxiety, depression and pain in adults with juvenile idiopathic arthritis (JIA).

PATIENTS AND METHODS

Two hundred and forty-six adults identified with long-standing JIA had an average disease duration of 28.3 yr. Candidate factors potentially predictive for pain, anxiety and depression were assessed by multiple regression analysis.

RESULTS

Of the patients, 31.6% were anxious, 5.2% were depressed, and 21.1% had previously suffered from depression. The percentage of the variance accounted for by other variables was 78.8 for anxiety variance and 54.5 for depression, but there was little influence from physical disease-related factors. Severe pain, measured on a visual analogue scale, occurred in 32.9% of patients, and 22.8% had poor perceived control over their pain. Function, coping strategies, pain self-efficacy, inflammation and previous depression could predict 39.6% of the variance in pain.

CONCLUSIONS

Comparing adults with children, disease activity and control over pain remain predictors of pain but become less important than disability and coping strategies.

Quantitative trait loci on chromosomes 1, 2, 3, 4, 8, 9, 11, 12, and 18 control variation in levels of T and B lymphocyte subpopulations

Lymphocyte subpopulation levels are used for prognosis and monitoring of a variety of human diseases, especially those with an infectious etiology. As a primary step to defining the major gene variation underlying these phenotypes, we conducted the first whole-genome screen for quantitative variation in lymphocyte count, CD4 T cell, CD8 T cell, B cell, and natural killer cell numbers, as well as CD4:CD8 ratio. The screen was performed in 15 of the CEPH families that form the main human genome genetic project mapping resource. Quantitative-trait loci (QTLs) that account for significant proportions of the phenotypic variance of lymphocyte subpopulations were detected on chromosomes 1, 2, 3, 4, 8, 9, 11, 12, and 18. The most significant QTL found was for CD4 levels on chromosome 8 (empirical P=.00005). Two regions of chromosome 4 showed significant linkage to CD4:CD8 ratio (empirical P=.00007 and P=.003). A QTL for the highly correlated measures of CD4 and CD19 levels colocalized at 18q21 (both P=.003). Similarly, a shared region of chromosome 1 was linked to CD8 and CD19 levels (P=.0001 and P=.002, respectively). Several of the identified chromosome regions are likely to harbor polymorphic candidate genes responsible for these important human phenotypes. Their discovery has important implications for understanding the generation of the immune repertoire and understanding immune-system homeostasis. More generally, these data show the power of an integrated human gene-mapping approach for heritable molecular phenotypes, using large pedigrees that have been extensively genotyped.

A development environment for predictive modelling in foods

Waikato Environment for Knowledge Analysis (WEKA) is a comprehensive suite of Java class libraries that implement many state-of-the-art machine learning/data mining algorithms. Non-programmers interact with the software via a user interface component called the Knowledge Explorer. Applications constructed from the WEKA class libraries can be run on any computer with a web-browsing capability, allowing users to apply machine learning techniques to their own data regardless of computer platform. This paper describes the user interface component of the WEKA system in reference to previous applications in the predictive modelling of foods.

Trust in physicians and medical institutions: what is it, can it be measured, and does it matter?

Despite the profound and pervasive importance of trust in medical settings, there is no commonly shared understanding of what trust means, and little is known about what difference trust actually makes, what factors affect trust, and how trust relates to other similar attitudes and behaviors. To address this gap in understanding, the emerging theoretical, empirical, and public policy literature on trust in physicians and in medical institutions is reviewed and synthesized. Based on this review and additional research and analysis, a formal definition and conceptual model of trust is presented, with a review of the extent to which this model has been confirmed by empirical studies. This conceptual and empirical understanding has significance for ethics, law, and public policy.

Trust in physicians and medical institutions: what is it, can it be measured, and does it matter?

Despite the profound and pervasive importance of trust in medical settings, there is no commonly shared understanding of what trust means, and little is known about what difference trust actually makes, what factors affect trust, and how trust relates to other similar attitudes and behaviors. To address this gap in understanding, the emerging theoretical, empirical, and public policy literature on trust in physicians and in medical institutions is reviewed and synthesized. Based on this review and additional research and analysis, a formal definition and conceptual model of trust is presented, with a review of the extent to which this model has been confirmed by empirical studies. This conceptual and empirical understanding has significance for ethics, law, and public policy.

Genetic determinism in the relationship between human CD4+ and CD8+ T lymphocyte populations?

The adaptive immune system in mammals acts in a coordinated manner to eliminate environmentally derived pathogens. Humans, mice and rats show within species variation in the levels and ratios of their peripheral CD4+ and CD8+ T cells and to a significant degree this variation is under the control of polymorphic genes. Whether genes act separately to specify CD4+ and CD8+ subpopulation levels or whether CD8+ variation is controlled through gene and environmental action on CD4+ cells or vice versa, is not known. We use a quantitative modelling approach in identical and non-identical female human twins to delineate the lines of control which act upon and between CD4+ and CD8+ subsets. The major findings of the study are: (1) genetic variation controls CD8+ T cell levels through two major routes-the first is via an effect on CD4+ T cells which accounts for the observed co-variation between CD4+ and CD8+ T cells, the second is through direct action on CD8+ T cell levels. (2) No evidence of a gene effect from CD8+ T cells on CD4+ cells is observed. Our findings have implications for the evolution of the complex defence system of which CD4+ and CD8+ T cells are a crucial part and encourage further work towards locating common pleiotropic quantitative trait loci responsible for variation in numbers of T cells.

Warm tropical sea surface temperatures in the Late Cretaceous and Eocene epochs

Climate models with increased levels of carbon dioxide predict that global warming causes heating in the tropics, but investigations of ancient climates based on palaeodata have generally indicated cool tropical temperatures during supposed greenhouse episodes. For example, in the Late Cretaceous and Eocene epochs there is abundant geological evidence for warm, mostly ice-free poles, but tropical sea surface temperatures are generally estimated to be only 15-23 degrees C, based on oxygen isotope palaeothermometry of surface-dwelling planktonic foraminifer shells. Here we question the validity of most such data on the grounds of poor preservation and diagenetic alteration. We present new data from exceptionally well preserved foraminifer shells extracted from impermeable clay-rich sediments, which indicate that for the intervals studied, tropical sea surface temperatures were at least 28-32 degrees C. These warm temperatures are more in line with our understanding of the geographical distributions of temperature-sensitive fossil organisms and the results of climate models with increased CO2 levels.

The structure and enforcement of health insurance rating reforms

Requiring health insurers to cover everyone who applies regardless of health status--an approach called "guaranteed issue"--is severely hampered without accompanying rating restrictions that keep insurance affordable for higher-risk people. The degree of rating flexibility also determines how much insurers can continue to compete based on their skills at risk selection, and how well they can counter adverse selection. Therefore, the structure and enforcement of rating reforms are essential to how insurance market reforms function. Based on an in-depth qualitative study in seven states with insurers, agents, and regulators, this article explains the factors that determine the stringency of rating reforms, and details how various aspects of rating restrictions can be used strategically to engage in greater risk segmentation than first appears possible. The article concludes by reflecting on the appropriate degree of complexity in rating rules, and it offers recommendations for crafting rating reforms that avoid unintended consequences.

Ethylene signal perception and transduction: multiple paradigms?

Current progress on the mechanisms of ethylene signal perception and transduction are reviewed with an emphasis on reconciling data from molecular genetics and from biochemical approaches. It is proposed that there exist two or more interacting transduction pathways.

HealthMarts, HIPCs (health insurance purchasing cooperatives), MEWAs (multiple employee welfare arrangements), and AHPs (association health plans): a guide for the perplexed

This paper considers how pending proposals to authorize new forms of group purchasing arrangements for health insurance would fit and function within the existing, highly complex market and regulatory landscape and whether these proposals are likely to meet their stated objectives and avoid unintended consequences. Cost savings are more likely to result from increased risk segmentation than through true market efficiencies. Thus, these proposals could erode previous market reforms whose goal is increased risk pooling. On the other hand, these proposals contain important enhancements, clarifications, and simplification of state and federal regulatory oversight of group purchasing vehicles. Also, they address some of the problems that have hampered the performance of purchasing cooperatives. On balance, although these proposals should receive cautious and careful consideration, they are not likely to produce a significant overall reduction in premiums or increase in coverage.

Purchasing cooperatives for small employers: performance and prospects

Health insurance purchasing cooperatives were established in the early to mid-1990s for the purpose of making health insurance more affordable and accessible for small employers. Extensive interviews at six cooperatives reveal that while some cooperatives enrolled large numbers of small employers, most have won only small market shares and a number have struggled for survival, not always successfully. They have allowed small employers to offer individual employees choice of health plans, but none has been able to sustain lower prices than are available in the conventional market. Among the important impediments to their success are limited support from health plans and conflicts over the role of insurance agents.

Interleukin-11 signals through the formation of a hexameric receptor complex

Interleukin-11 (IL-11) is a member of the gp130 family of cytokines. These cytokines drive the assembly of multisubunit receptor complexes, all of which contain at least one molecule of the transmembrane signaling receptor gp130. IL-11 has been shown to induce gp130-dependent signaling through the formation of a high affinity complex with the IL-11 receptor (IL-11R) and gp130. Site-directed mutagenesis studies have identified three distinct receptor binding sites of IL-11, which enable it to form this high affinity receptor complex. Here we present data from immunoprecipitation experiments, using differentially tagged forms of ligand and soluble receptor components, which show that multiple copies of IL-11, IL-11R, and gp130 are present in the receptor complex. Furthermore, it is demonstrated that sites II and III of IL-11 are independent gp130 binding epitopes and that both are essential for gp130 dimerization. We also show that a stable high affinity complex of IL-11, IL-11R, and gp130 can be resolved by nondenaturing polyacrylamide gel electrophoresis, and its composition verified by second dimension denaturing polyacrylamide gel electrophoresis. Results indicate that the three receptor binding sites of IL-11 and the Ig-like domain of gp130 are all essential for this stable receptor complex to be formed. We therefore propose that IL-11 forms a hexameric receptor complex composed of two molecules each of IL-11, IL-11R, and gp130.

Genetic influence on peripheral blood T lymphocyte levels

T lymphocytes are a major component of the adaptive immune system. CD4 positive T cell subpopulations regulate B cell and macrophage effector function while CD8 positive T cells are largely responsible for anti-viral cytotoxic activity. The degree of natural variation in the levels and ratios of the various T cell subpopulations is a possible risk factor for the development of autoimmune disease, infectious disease and cancer. There is some evidence from studies of inbred strains of mice and humans which suggests that variation in T cell subpopulations is genetically influenced. However, family studies alone cannot distinguish between common environmental and shared genetic influences and provide less robust estimates of the heritability than twin studies. To comprehensively examine genetic influences on a selection of important T cell phenotypes, we investigated variation in levels of total lymphocytes, CD3+, CD4+, CD8+, CD3+CD4+, CD3+CD8+ lymphocytes and in CD4:CD8 ratio as a proportion of lymphocytes and of T cells using the classical twin model approach. Healthy female twin pairs were sampled from the St. Thomas' UK Adult Twin Registry. A maximum of 103 monozygotic (MZ) and 186 dizygotic (DZ) twins aged 18-80 years participated in the study. Whole blood samples were analysed for T cell subsets by flow cytometry. The relative genetic contribution to these phenotypes was estimated using a variance components model-fitting approach. Heritability estimates were calculated of 65% for CD4:CD8 T cell and lymphocyte ratios, around 50% for absolute lymphocyte, CD3+ and CD4+ counts, and 56% for CD8+ numbers. Unique (rather than shared) familial environment explains the remainder of the variance. Genetic factors have a major influence on the variation in peripheral T cell subset numbers. Polymorphism dictating such variation should be taken into account when assessing risk factors for T cell immune-mediated disease with a genetic background.

Patients' fear of genetic discrimination by health insurers: the impact of legal protections

PURPOSE

The impact of laws restricting health insurers' use of genetic information has been assessed from two main vantage points: (1) whether they reduce the extent of genetic discrimination and (2) whether they reduce the fear of discrimination and the resulting deterrence to undergo genetic testing. A previous report from this study concluded that there are almost no well-documented cases of health insurers either asking for or using presymptomatic genetic test results in their underwriting decisions, either before or after these laws, or in states with or without these laws. This report evaluates the perceptions and the resulting behavior by patients and clinicians.

METHODS

A comparative case study analysis was performed in seven states with different laws respecting health insurers' use of genetic information (no law, new prohibition, mature prohibition). Semistructured interviews were conducted in person with five patient advocates and with 30 experienced genetic counselors or medical geneticists, most of whom deal with adult-onset disorders. Also, multiple informed consent forms and patient information brochures were collected and analyzed using qualitative methods.

RESULTS

Patients' and clinicians' fear of genetic discrimination greatly exceeds reality, at least for health insurance. It is uncertain how much this fear actually deters genetic testing. The greatest deterrence is to those who do not want to submit the costs of testing for reimbursement and who cannot afford to pay for testing. There appears to be little deterrence for tests that are more easily affordable or when the need for the information is much greater. Fear of discrimination plays virtually no role in testing decisions in pediatric or prenatal situations, but is significant for adult-onset genetic conditions.

CONCLUSION

Existing laws have not greatly reduced the fear of discrimination. This may be due, in part, to clinicians' lack of confidence that these laws can prevent discrimination until there are test cases of actual enforcement. Ironically, there may be so little actual discrimination that it may not be possible to initiate good test cases.

Disclosure of physician incentives: do practices satisfy purposes?

Under legal pressure, discussion has quickly shifted from whether health plans should disclose how they pay their physicians to how, when, and what should be disclosed and by whom. This paper describes health plans' disclosure practices and evaluates their adequacy and likely impact. It begins by explaining how different reasons for disclosure alter the form and content of disclosure, illustrating these approaches with actual examples. The paper concludes with a recommended approach that attempts to layer and stage disclosures so that people have as much information as they want, when they need it.

Audit of rheumatology services for adolescents and young adults in the UK. British Paediatric Rheumatology Group

BACKGROUND

Juvenile idiopathic arthritis (JIA) is associated with significant morbidity in adulthood with at least one third of children continuing to have active inflammatory disease into their adult years and up to 60% of all patients continuing to have some limitation of their activities of daily living. A survey of service provision for these young people in the transition from paediatric to adult rheumatology care was therefore undertaken.

METHODS

A postal questionnaire was sent to all 92 members of the British Paediatric Rheumatology Group, representing 61 units providing a paediatric rheumatology service in the UK and Eire.

RESULTS

Fifty-five replies were received representing a 60% completion rate of doctors and 84% of units on the mailing list. The majority of respondents were adult rheumatologists (n = 36, 65%) with 42% of respondents based in teaching hospitals. A median of 24 patients (new and follow-up, range 1-225) were seen in a median of two paediatric rheumatology clinics (range 0-15) per month. Eighteen per cent of units had a dedicated adolescent clinic (n = 9) with a median of one clinic per month and a median number of new patients per month of two (range 0-24) and 10 review patients (4-32). All the adolescent clinics involved an adult rheumatologist with five having a paediatrician in clinic and four having access to a paediatrician. The majority of clinics involved a specialist registrar (n = 6), a nurse specialist (n = 6), an occupational therapist (n = 6) and a physiotherapist (n = 5). The majority of clinics had flexible entry and exit criteria. In seven clinics there was a standardized process of transfer, first discussed at a median age of 13 yr (range 12-16) but no unit provided literature or organized pre-visits for this process. A demand for patient information resources (e.g. disease and drug information, careers) specifically aimed at adolescents with rheumatic diseases was identified. Generic health issues were only addressed by two clinics. Obstacles to current service provision and ideas for future developments were identified.

CONCLUSIONS

This survey identifies a heterogeneity of provision of healthcare for adolescents with rheumatic disease and highlights the potential for further research and development.

The effect of ethylene on MAPKinase-like activity in Arabidopsis thaliana

Protein kinase activity was studied in cytosolic extracts from leaves of wild type Arabidopsis thaliana, the ethylene-insensitive mutant, etr1, and the constitutive triple-response mutant, ctr1. Treatment of wild type with ethylene resulted in increased myelin basic protein (MBP) phosphorylation. In etr1, constitutive protein kinase activity was lower than in wild type, but in ctr1, activity was enhanced. A protein of M(r) approximately 47 kDa associated with MBP-phosphorylating activity was detected using in gel protein kinase assays and phosphorylation of this protein was promoted by ethylene treatment in wild type while activity in the mutants reflected that of MBP phosphorylation. Both MAPKinase (ERK 1) and phosphotyrosine antibodies immunoprecipitated MBP-phosphorylating activity and detected a polypeptide band at M(r) approximately 47 kDa. Immunoprecipitated MBP-phosphorylating activity was again much lower in etr1 compared to wild type but much higher in ctr1. Antibodies to phosphorylated MAPKinase recognised proteins at approximately 47 kDa and the signal was upregulated in response to ethylene. The data obtained suggest that the detected protein(s) is a MAPKinase and provide further evidence confirming that a MAPKinase cascade(s) is involved in ethylene signal transduction.

The geography of health insurance regulation

The health insurance market consists of three distinct segments--individual, small group, and large group--each governed by different economic and regulatory structures. A number of border-crossing techniques have arisen for avoiding the burdens of one segment and capitalizing on the benefits of others. Drawing from extensive qualitative research into the functioning of existing market structures, this paper describes these techniques and their purposes and effects. This road map helps to identify which reform proposals seek to produce true economic efficiencies and which have the potential to undermine previous reform objectives.

The role of independent agents in the success of health insurance market reforms

The impact of reforms on the health insurance markets cannot be understood without more information about the role played by insurance agents and a closer analysis of their contribution. An in-depth, qualitative study of insurance-market reforms in seven illustrative states forms the basis for this report on how agents help to shape the efficiency and fairness of insurance markets. Different types of agents relate to insurers in their own ways and are compensated differently. This study shows agents to be almost uniformly enthusiastic about guaranteed-issue requirements and other components of market reforms. Although insurers devise strategies for manipulating agents in order to avoid undesirable business, these opportunities are limited and do not appear to be seriously undermining the effectiveness of market reforms. Despite the layer of cost that agents add to the system, they play an important role in making market reforms work, and they fill essential information and service functions for which many purchasers have no ready substitute.

Genetic polymorphism of IL-12 p40 gene in immune-mediated disease

Understanding of the genetic basis of autoimmune diseases is currently incomplete. Cytokine gene polymorphisms warrant consideration as factors explaining variation in the human immune and inflammatory responses and as candidate susceptibility genes for related pathological states. Interleukin 12 (IL-12) is a key regulator of the polarisation of immune responses to T helper 1 or 2 categories and plays a role in autoimmune and infectious diseases. Using a bioinformatic strategy, we aligned cDNA and expressed sequence tag sequences to identify putative polymorphic regions of the IL-12 p40 gene. Position 1188 in the 3' untranslated region (UTR) was polymorphic with the frequency of the common allele around 80% in healthy UK Caucasoids. PCR genotyping of multiple Caucasoid groups and an African group showed significant population variation. In a case-control design, the polymorphism was not associated with rheumatoid arthritis, Felty's syndrome or large granular lymphocyte syndrome with arthritis or multiple sclerosis. A nonsignificant increase in the B allele frequency was observed in the rare large granular lymphocyte syndrome without arthritis (odds ratio 2.02 95% CI 0.95-4.3). This new genetic marker could be useful in anthropological studies and should be investigated in other autoimmune, allergic, inflammatory and infectious diseases.