Ex vivo activation of the GCN2 pathway metabolically reprograms T cells, leading to enhanced adoptive cell therapy

The manipulation of T cell metabolism to enhance anti-tumor activity is an area of active investigation. Here, we report that activating the amino acid starvation response in effector CD8+ T cells ex vivo using the general control non-depressible 2 (GCN2) agonist halofuginone (halo) enhances oxidative metabolism and effector function. Mechanistically, we identified autophagy coupled with the CD98-mTOR axis as key downstream mediators of the phenotype induced by halo treatment. The adoptive transfer of halo-treated CD8+ T cells into tumor-bearing mice led to robust tumor control and curative responses. Halo-treated T cells synergized in vivo with a 4-1BB agonistic antibody to control tumor growth in a mouse model resistant to immunotherapy. Importantly, treatment of human CD8+ T cells with halo resulted in similar metabolic and functional reprogramming. These findings demonstrate that activating the amino acid starvation response with the GCN2 agonist halo can enhance T cell metabolism and anti-tumor activity.

IDH2 and TET2 mutations synergize to modulate T Follicular Helper cell functional interaction with the AITL microenvironment

Angioimmunoblastic T cell lymphoma (AITL) is a peripheral T cell lymphoma that originates from T follicular helper (Tfh) cells and exhibits a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL, but their contribution to tumorigenesis is poorly understood. We developed an AITL mouse model that is driven by Idh2 and Tet2 mutations. Malignant Tfh cells display aberrant transcriptomic and epigenetic programs that impair TCR signaling. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered cross-talk with germinal center B cells that promotes B cell clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. The plasma cell count and angiogenesis are also increased in the Idh2-mutated tumors, implying a major relationship between Idh2 mutation and the characteristic AITL TME. Our mouse model recapitulates several features of human IDH2-mutated AITL and provides a rationale for exploring therapeutic targeting of Tfh-TME cross-talk for AITL patients.

Galectin-9 regulates the threshold of B cell activation and autoimmunity

Despite the mechanisms of central and peripheral tolerance, the mature B cell compartment contains cells reactive for self-antigen. How these cells are poised not to respond and the mechanisms that restrain B cell responses to low-affinity endogenous antigens are not fully understood. Here, we demonstrate a critical role for the glycan-binding protein galectin-9 in setting the threshold of B cell activation and that loss of this regulatory network is sufficient to drive spontaneous autoimmunity. We further demonstrate a critical role for galectin-9 in restraining not only conventional B-2 B cells, but also innate-like B-1a cells. We show that galectin-9-deficient mice have an expanded population of B-1a cells and increased titers of B-1a-derived autoantibodies. Mechanistically, we demonstrate that galectin-9 regulates BCR and distinct TLR responses in B-1a cells, but not B-1b cells, by regulating the interaction between BCR and TLRs with the regulatory molecules CD5 and CD180, respectively. In the absence of galectin-9, B-1a cells are more readily activated and secrete increased titers of autoantibodies that facilitate autoantigen delivery to the spleen, driving autoimmune responses.

Associations between social and behavioural factors and the risk of late stillbirth - findings from the Midland and North of England Stillbirth case-control study

OBJECTIVE

To investigate behavioural and social characteristics of women who experienced a late stillbirth compared with women with ongoing live pregnancies at similar gestation.

DESIGN

Case-control study.

SETTING

41 maternity units in the UK.

POPULATION

Women who had a stillbirth ≥28 weeks' gestation (n = 287) and women with an ongoing pregnancy at the time of interview (n = 714).

METHODS

Data were collected using an interviewer-administered questionnaire which included questions regarding women's behaviours (e.g. alcohol intake and household smoke exposure) and social characteristics (e.g. ethnicity, employment, housing). Stress was measured by the 10-item Perceived Stress Scale.

MAIN OUTCOME MEASURE

Late stillbirth.

RESULTS

Multivariable analysis adjusting for co-existing social and behavioural factors showed women living in the most deprived quintile had an increased risk of stillbirth compared with the least deprived quintile (adjusted odds ratio [aOR] 3.16; 95% CI 1.47-6.77). There was an increased risk of late stillbirth associated with unemployment (aOR 2.32; 95% CI 1.00-5.38) and women who declined to answer the question about domestic abuse (aOR 4.12; 95% CI 2.49-6.81). A greater number of antenatal visits than recommended was associated with a reduction in stillbirth (aOR 0.26; 95% CI 0.16-0.42).

CONCLUSIONS

This study demonstrates associations between late stillbirth and socio-economic deprivation, perceived stress and domestic abuse, highlighting the need for strategies to prevent stillbirth to extend beyond maternity care. Enhanced antenatal care may be able to mitigate some of the increased risk of stillbirth.

TWEETABLE ABSTRACT

Deprivation, unemployment, social stress & declining to answer about domestic abuse increase risk of #stillbirth after 28 weeks' gestation.

Parents' experiences of care following the loss of a baby at the margins between miscarriage, stillbirth and neonatal death: a UK qualitative study

OBJECTIVE

To explore the healthcare experiences of parents whose baby died either before, during or shortly after birth between 20⁺⁰ and 23⁺⁶  weeks of gestation in order to identify practical ways to improve healthcare provision.

DESIGN

Qualitative interview study.

SETTING

England through two parent support organisations and four NHS Trusts.

SAMPLE

A purposive sample of parents.

METHODS

Thematic analysis of semi-structured in-depth narrative interviews.

MAIN OUTCOME MEASURES

Parents' healthcare experiences.

RESULTS

The key overarching theme to emerge from interviews with 38 parents was the importance of the terminology used to refer to the death of their baby. Parents who were told they were 'losing a baby' rather than 'having a miscarriage' were more prepared for the realities of labour, the birth experience and for making decisions around seeing and holding their baby. Appropriate terminology validated their loss, and impacted on parents' health and wellbeing immediately following bereavement and in the longer term.

CONCLUSION

For parents experiencing the death of their baby at the margins between miscarriage, stillbirth and neonatal death, ensuring the use of appropriate terminology that reflects parents' preferences is vital. This helps to validate their loss and prepare them for the experiences of labour and birth. Reflecting parents' language preferences combined with compassionate bereavement care is likely to have a positive impact on parents' experiences and improve longer-term outcomes.

TWEETABLE ABSTRACT

Describing baby loss shortly before 24 weeks of gestation as a 'miscarriage' does not prepare parents for labour and birth, seeing their baby and making memories.

Galectin-Glycan Interactions as Regulators of B Cell Immunity

Cell surface glycans and their glycan-binding partners (lectins) have generally been recognized as adhesive assemblies with neighbor cells or matrix scaffolds in organs and the blood stream. However, our understanding of the roles for glycan-lectin interactions in immunity has expanded substantially to include regulation of nearly every stage of an immune response, from pathogen sensing to immune contraction. In this Mini-Review, we discuss the role of the ß-galactoside-binding lectins known as galectins specifically in the regulation of B-lymphocyte (B cell) development, activation, and differentiation. In particular, we highlight several recent studies revealing new roles for galectin (Gal)-9 in the modulation of B cell receptor-mediated signaling and activation in mouse and man. The roles for cell surface glycosylation, especially I-branching of N-glycans synthesized by the glycosyltransferase GCNT2, in the regulation of Gal-9 binding activity are also detailed. Finally, we consider how dysregulation of these factors may contribute to aberrant immune activation and autoimmune disease.

Interleukin-10 Directly Inhibits CD8+ T Cell Function by Enhancing N-Glycan Branching to Decrease Antigen Sensitivity

Chronic viral infections remain a global health concern. The early events that facilitate viral persistence have been linked to the activity of the immunoregulatory cytokine IL-10. However, the mechanisms by which IL-10 facilitates the establishment of chronic infection are not fully understood. Herein, we demonstrated that the antigen sensitivity of CD8⁺ T cells was decreased during chronic infection and that this was directly mediated by IL-10. Mechanistically, we showed that IL-10 induced the expression of Mgat5, a glycosyltransferase that enhances N-glycan branching on surface glycoproteins. Increased N-glycan branching on CD8⁺ T cells promoted the formation of a galectin 3-mediated membrane lattice, which restricted the interaction of key glycoproteins, ultimately increasing the antigenic threshold required for T cell activation. Our study identified a regulatory loop in which IL-10 directly restricts CD8⁺ T cell activation and function through modification of cell surface glycosylation allowing the establishment of chronic infection.

Protein Tyrosine Phosphatase Inhibition Prevents Experimental Cerebral Malaria by Precluding CXCR3 Expression on T Cells

Cerebral malaria induced by Plasmodium berghei ANKA infection is dependent on the sequestration of cytotoxic T cells within the brain and augmentation of the inflammatory response. Herein, we demonstrate that inhibition of protein tyrosine phosphatase (PTP) activity significantly attenuates T cell sequestration within the brain and prevents the development of neuropathology. Mechanistically, the initial upregulation of CXCR3 on splenic T cells upon T cell receptor stimulation was critically decreased through the reduction of T cell-intrinsic PTP activity. Furthermore, PTP inhibition markedly increased IL-10 production by splenic CD4⁺ T cells by enhancing the frequency of LAG3⁺CD49b⁺ type 1 regulatory cells. Overall, these findings demonstrate that modulation of PTP activity could possibly be utilized in the treatment of cerebral malaria and other CXCR3-mediated diseases.

Variations in very preterm birth rates in 30 high-income countries: are valid international comparisons possible using routine data?

OBJECTIVE

Concerns about differences in registration practices across countries have limited the use of routine data for international very preterm birth (VPT) rate comparisons.

DESIGN

Population-based study.

SETTING

Twenty-seven European countries, the United States, Canada and Japan in 2010.

POPULATION

A total of 9 376 252 singleton births.

METHOD

We requested aggregated gestational age data on live births, stillbirths and terminations of pregnancy (TOP) before 32 weeks of gestation, and information on registration practices for these births. We compared VPT rates and assessed the impact of births at 22-23 weeks of gestation, and different criteria for inclusion of stillbirths and TOP on country rates and rankings.

MAIN OUTCOME MEASURES

Singleton very preterm birth rate, defined as singleton stillbirths and live births before 32 completed weeks of gestation per 1000 total births, excluding TOP if identifiable in the data source.

RESULTS

Rates varied from 5.7 to 15.7 per 1000 total births and 4.0 to 11.9 per 1000 live births. Country registration practices were related to percentage of births at 22-23 weeks of gestation (between 1% and 23% of very preterm births) and stillbirths (between 6% and 40% of very preterm births). After excluding births at 22-23 weeks, rate variations remained high and with a few exceptions, country rankings were unchanged.

CONCLUSIONS

International comparisons of very preterm birth rates using routine data should exclude births at 22-23 weeks of gestation and terminations of pregnancy. The persistent large rate variations after these exclusions warrant continued surveillance of VPT rates at 24 weeks and over in high-income countries.

TWEETABLE ABSTRACT

International comparisons of VPT rates should exclude births at 22-23 weeks of gestation and terminations of pregnancy.

The atypical two-subunit σ factor from Bacillus subtilis is regulated by an integral membrane protein and acid stress

Extracytoplasmic function (ECF) σ factors constitute a major component of the physicochemical sensory apparatus in bacteria. Most ECF σ factors are co-expressed with a negative regulator called an anti-σ factor that binds to its cognate σ factor and sequesters it from productive association with core RNA polymerase (RNAP). Anti-σ factors constitute an important element of signal transduction pathways that mediate an appropriate transcriptional response to changing environmental conditions. The Bacillus subtilis genome encodes seven canonical ECF σ factors and six of these are co-expressed with experimentally verified anti-σ factors. B. subtilis also expresses an ECF-like atypical two-subunit σ factor composed of subunits SigO and RsoA that becomes active after exposure to certain cell-wall-acting antibiotics and to growth under acidic conditions. This work describes the identification and preliminary characterization of a protein (RsiO, formerly YvrL) that constitutes the anti-σ factor cognate to SigO-RsoA. Synthesis of RsiO represses SigO-RsoA-dependent transcription initiation by binding the N-terminus of SigO under neutral (pH 7) conditions. Reconstitution of the SigO-RsoA-RsiO regulatory system into a heterologous host reveals that the imposition of acid stress (pH 5.4) abolishes the ability of RsiO to repress SigO-RsoA-dependent transcription and this correlates with loss of RsiO binding affinity for SigO. A current model for RsiO function indicates that RsiO responds, either directly or indirectly, to increased extracytoplasmic hydrogen ion concentration and becomes inactivated. This results in the release of SigO into the cytoplasm, where it productively associates with RsoA and core RNAP to initiate transcription from target promoters in the cell.

Functional reconstitution of an unusual Firmicutes σ factor into a Gram-negative heterologous host

Sigma (σ) factors are single-subunit proteins that reversibly bind RNA polymerase and play an important role in the transcription initiation process. An unusual 2-subunit σ factor, consisting of proteins SigO and RsoA, activates transcription from a group of related promoters in Bacillus subtilis. These 2 proteins specifically interact with each other and with RNA polymerase subunits. This system is widespread among species in several Bacillus-related genera, but otherwise appears restricted to the Firmicutes. Here, we reconstituted SigO-RsoA, and a cognate promoter, into the distantly related heterologous host Escherichia coli to examine whether this system can function in bacteria outside of the Firmicutes. We show that these proteins can productively associate with E. coli RNA polymerase and activate transcription, demonstrating that there are no structural barriers to function. In parallel, we tested a wide array of protein-protein interaction mutations and promoter mutations that impact SigO-RsoA function in both B. subtilis and E. coli and conclude that the SigO-RsoA system behaves, in most instances, similarly in both genetic backgrounds. These data raise the possibility of genetically isolating the system in this heterologous host and away from unknown B. subtilis factors that may also be playing a role in SigO-RsoA regulatory pathways, thus facilitating further study of the system. As a result of this work, we also provide a comprehensive mutational analysis of a SigO-RsoA promoter and report the preliminary identification of amino acids in SigO that play a role in mediating the SigO-RsoA protein-protein interaction.

Economic costs associated with moderate and late preterm birth: a prospective population-based study

OBJECTIVE

We sought to determine the economic costs associated with moderate and late preterm birth.

DESIGN

An economic study was nested within a prospective cohort study.

SAMPLE

Infants born between 32(+0) and 36(+6)  weeks of gestation in the East Midlands of England. A sample of infants born at ≥37 weeks of gestation acted as controls.

METHODS

Data on resource use, estimated from a National Health Service (NHS) and personal social services perspective, and separately from a societal perspective, were collected between birth and 24 months corrected age (or death), and valued in pounds sterling, at 2010-11 prices. Descriptive statistics and multivariable analyses were used to estimate the relationship between gestational age at birth and economic costs.

MAIN OUTCOME MEASURES

Cumulative resource use and economic costs over the first two years of life.

RESULTS

Of all eligible births, 1146 (83%) preterm and 1258 (79%) term infants were recruited. Mean (standard error) total societal costs from birth to 24 months were £12 037 (£1114) and £5823 (£1232) for children born moderately preterm (32(+0) -33(+6)  weeks of gestation) and late preterm (34(+0) -36(+6)  weeks of gestation), respectively, compared with £2056 (£132) for children born at term. The mean societal cost difference between moderate and late preterm and term infants was £4657 (bootstrap 95% confidence interval, 95% CI £2513-6803; P < 0.001). Multivariable regressions revealed that, after controlling for clinical and sociodemographic characteristics, moderate and late preterm birth increased societal costs by £7583 (£874) and £1963 (£337), respectively, compared with birth at full term.

CONCLUSIONS

Moderate and late preterm birth is associated with significantly increased economic costs over the first 2 years of life. Our economic estimates can be used to inform budgetary and service planning by clinical decision-makers, and economic evaluations of interventions aimed at preventing moderate and late preterm birth or alleviating its adverse consequences.

TWEETABLE ABSTRACT

Moderate and late preterm birth is associated with increased economic costs over the first 2 years of life.

Experiences with maternal and perinatal death reviews in the UK--the MBRRACE-UK programme

Established in 1952, the programme of surveillance and Confidential Enquiries into Maternal Deaths in the UK is the longest running such programme worldwide. Although more recently instituted, surveillance and confidential enquiries into perinatal deaths are also now well established nationally. Recent changes to funding and commissioning of the Enquiries have enabled both a reinvigoration of the processes and improvements to the methodology with an increased frequency of future reporting. Close engagement with stakeholders and a regulator requirement for doctors to participate have both supported the impetus for involvement of all professionals leading to greater potential for improved quality of care for women and babies.

Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

Post-operative blood salvage with autologous retransfusion in primary total hip replacement

Clinical, haematological or economic benefits of post-operative blood salvage with autologous blood re-transfusion have yet to be clearly demonstrated for primary total hip replacement. We performed a prospective randomised study to analyse differences in postoperative haemoglobin levels and homologous blood requirements in two groups of patients undergoing primary total hip replacement. A series of 158 patients was studied. In one group two vacuum drains were used and in the other the ABTrans autologous retransfusion system. A total of 58 patients (76%) in the re-transfusion group received autologous blood. There was no significant difference in the mean post-operative haemoglobin levels in the two groups. There were, however, significantly fewer patients with post-operative haemoglobin values less than 9.0 g/dl and significantly fewer patients who required transfusion of homologous blood in the re-transfusion group. There was also a small overall cost saving in this group.

Mortality in adults with moderate to profound intellectual disability: a population-based study

BACKGROUND

People with intellectual disability (ID) experience a variety of health inequalities compared with the general population including higher mortality rates. This is the first UK population-based study to measure the extent of excess mortality in people with ID compared with the general population.

METHOD

Indirectly standardized all-cause and disease mortality ratios (SMRs) and exact Poisson confidence intervals were calculated by age and sex for all adults, aged 20 years or over, with moderate to profound ID living in Leicestershire and Rutland, UK, between 1993 and 2005. The general population of Leicestershire and Rutland, which has a population of approximately 700,000 individuals in this age range, was used for comparison. To explore differences within the study population, overall SMRs were also calculated by presence of Down syndrome and last place of residence (city or county).

RESULTS

Of 2436 adults identified, 409 (17%) died during 23,000 person-years of follow-up. Both all-cause and disease-specific mortality were around three times higher than the general population but varied considerably with age. The largest differences were observed in people in their twenties, where all-cause mortality was almost nine times higher in men (SMR=883; 95% CI=560-1325) and more than 17 times higher in women (SMR=1722; 95% CI=964-2840). At a particular disadvantage were people with Down syndrome and women with ID living in the city.

CONCLUSIONS

The relatively high SMRs observed in young people and in women, particularly those living in inner city areas and with Down syndrome, deserve further investigation for possible explanations, including socio-economic factors.

The identification and characterisation of a novel null HLA-DRB1 allele

Since the introduction of DNA-based human leukocyte antigen (HLA) typing a number of discrepancies with serological typing have been documented. At the time of submission of this abstract (July 2005 ImMunoGeneTics project (IMGT) project database release) 42 HLA class I and II null alleles had been described characterised by a lack of expression of cell surface antigen. These null alleles can be accounted for by a number of demonstrated molecular mechanisms including insertion, deletion and point mutation and may lead to a nonsense codon, splicing defect or premature stop codon.

Sequencing-based typing identifies novel alleles due to single nucleotide polymorphisms in ‘conserved’ regions

The Royal Perth Hospital laboratory has been using sequencing-based typing for all HLA loci since 2002. In the period to October 2005, approximately 12,000 HLA A and HLA B, 5000 HLA C and DQB1, and 17,000 DRB1 requests have been processed. Twenty nine novel alleles have been identified in that time. These comprise 10 HLA-A (including one null allele), five HLA-B, six HLA-C, six DRB1 (including a null allele), and one DQB1 novel allele. (At the time of identifying the DRB1 null allele, there were no other reported examples.) In addition, we have seen one example of a blast-specific HLA-A null allele. One HLA-A allele (HLA-A*0264) and one HLA-B allele (HLA-B*400104) were subsequently identified in other laboratories and submitted to the international ImMunoGeneTics project (IMGT) database.

Socioeconomic inequalities in very preterm birth rates

AIMS

To investigate the extent of socioeconomic inequalities in the incidence of very preterm birth over the past decade.

METHODS

Ecological study of all 549 618 births in the former Trent health region, UK, from 1 January 1994 to 31 December 2003. All singleton births of 22(+0) to 32(+6) weeks gestation (7 185 births) were identified from population surveys of neonatal services and stillbirths. Poisson regression was used to calculate incidence of very preterm birth (22-32 weeks) and extremely preterm birth (22-28 weeks) by year of birth and decile of deprivation (child poverty section of the Index of Multiple Deprivation).

RESULTS

Incidence of very preterm singleton birth rose from 11.9 per 1000 births in 1994 to 13.7 per 1000 births in 2003. Those from the most deprived decile were at nearly twice the risk of very preterm birth compared with those from the least deprived decile, with 16.4 per 1000 births in the most deprived decile compared with 8.5 per 1000 births in the least deprived decile (incidence rate ratio 1.94; 95% CI (1.73 to 2.17)). This deprivation gap remained unchanged throughout the 10-year period. The magnitude of socio-economic inequalities was the same for extremely preterm births (22-28 weeks incidence rate ratio 1.94; 95% CI (1.62 to 2.32)).

CONCLUSIONS

This large, unique dataset of very preterm births shows wide socio-economic inequalities that persist over time. These findings are likely to have consequences on the burden of long-term morbidity. Our research can assist future healthcare planning, the monitoring of socio-economic inequalities and the targeting of interventions in order to reduce this persistent deprivation gap.

Up-to-date estimates of long-term cancer survival in England and Wales

Cancer survival in England and Wales has improved over the last 30 years. However, cohort survival estimates delay recognition of these improvements. Here we show that period survival estimates, based on survival in a recent time period, suggest a more optimistic pattern for England and Wales than cohort-based measures for most cancers.British Journal of Cancer (2003) 89, 74-76. doi:10.1038/sj.bjc.6600976 www.bjcancer.com

Latest trends in cancer incidence among UK South Asians in Leicester

Using cancer registry data, we show that although South Asians have lower rates of cancer than the rest of the population, this is changing with age and time. Younger South Asians, particularly children, are at increased risk. While generally cancer rates have fallen over the last decade, they are increasing among South Asians.

A study of heredity as a risk factor in strabismus

AIMS

Inheritance is recognised to have a part in the aetiology of strabismus but previous studies have not adequately distinguished between different types of strabismus leading to wide variations in reported findings. The aim of this study was to investigate the importance of heredity in different types of strabismus.

METHODS

The parents of children attending for treatment of strabismus over a one-month period were interviewed to identify relatives with a history of strabismus. A complete three-generation pedigree was established for 96 index cases who were classified into four groups: infantile esotropia (26 cases), accommodative esotropia (49 cases), anisometropic esotropia (15 cases), and exotropia (six cases).

RESULTS

Forty-three of a total of 165 (26.1%) first degree relatives of patients with hypermetropic accommodative esotropia were affected. In contrast, 15 of a total of 101 (14.9%) first degree relatives of patients with infantile esotropia, eight of a total of 66 (12.1%) first degree relatives of patients with anisometropic esotropia, and one of a total of 25 (4%) first degree relatives of patients with exotropia were affected. Analysing the data using logistic regression with a random term for family showed a significantly higher proportion of affected first degree relatives in the accommodative group than in any of the other three diagnostic groups.

CONCLUSION

A history of strabismus appears to be more common in hypermetropic accommodative esotropia than in infantile esotropia, anisometropic esotropia or exotropia. More detailed investigation of the role of heredity in the aetiology of accommodative esotropia is needed.

Changes in the diet of free-ranging black bears in years of contrasting food availability revealed through milk fatty acids

We studied patterns of fatty acid signatures in milks and major foods of free-ranging lactating black bears (Ursus americanus) in western Massachusetts to examine the degree to which changes in milk fatty acids could be related to measured changes in food availability and scat analysis, and to assess whether fatty acids could be used to infer aspects of the diets of individuals. Milk samples (n = 45) were obtained from 17 individual bears during years of contrasting hard-mast abundance. Paired winter-den and spring-foraging samples were obtained from females in 1994 (n = 10), 1995 (n = 2), and 1996 (n = 8). In seven of these females, paired den and foraging samples were collected in both 1994 and 1996, representing two consecutive lactation periods. Milk fatty acid patterns indicated that the diet of individuals responded strongly to food availability both prior to denning and during spring foraging. During spring foraging, although females likely continued to mobilize stored fat, the greatest contribution to milk fatty acids appeared to be from dietary fat intake. Hence, qualitative changes in spring diets of individual bears could be reasonably inferred from milk fatty acid signatures. During the year of lowest hard-mast abundance, milk fatty acid patterns suggested that females relied predominantly on a diet of skunk cabbage, although this varied among individuals. This study demonstrates that milk fatty acid signatures can be used to provide insight into the nutritional ecology of bears at the level of the individual.

Relation of coronary artery calcium identified by electron beam tomography to serum lipoprotein levels and implications for treatment

This study was designed to determine whether the National Cholesterol Education Program (NCEP) lipid guidelines accurately identify subclinical atherosclerosis and whether low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels are related to the extent and prematurity of coronary artery disease (CAD) as determined by electron beam tomography (EBT). Out of personal concern for CAD risk, 930 consecutive asymptomatic subjects, without clinical CAD and on no lipid-lowering agents, underwent EBT. Calcium score and percentile were correlated with total cholesterol (TC), LDL-C, HDL-C, triglycerides, and demographic parameters. A calcium score of > 0 (EBT+) was found in 55% of patients; 45% of patients had a 0 score (EBT-). Mean age (58.0 +/- 10.5 vs 49.3 +/- 9.7 years, p = 0.0001), TC (218 +/- 39 vs 211 +/- 41 mg/dl, p = 0.006), LDL-C (136 +/- 36 vs 127 +/- 27 mg/dl, p = 0.005), and TC/HDL-C (4.6 +/- 1.4 vs 4.2 +/- 1.5, p = 0.0001) were significantly higher and HDL-C (52.2 +/- 17.6 vs 55.4 +/- 19.3 mg/dl, p = 0.008) lower in the EBT+ compared with EBT- group. In the EBT+ group, 75.1% of subjects had LDL-C < 160 mg/dl and would not be advised to use lipid-lowering medications according to NCEP guidelines. In subjects with LDL-C < 160 mg/dl, 51.8% of subjects were EBT+, as were 46.1% of those with LDL-C < 100 mg/dl. There were no significant differences in the calcium scores throughout the entire range of all lipid parameters; calcium percentiles were virtually identical within lipid value subgroups. We conclude that asymptomatic patients with EBT-defined subclinical atherosclerosis are not reliably identified by NCEP guidelines, and TC, LDL-C, HDL-C, TC/HDL-C, and triglyceride levels do not correlate with either the extent or prematurity of calcified plaque burden.

A quality control program for crossmatching procedures for solid organ transplantation. The participating laboratories of the Australasian and South Asian Tissue Typing Association

The National Kidney Matching Scheme (NKMS) allows matching and allocation of donor organs throughout Australia. Sera from potential recipients are distributed to each interstate tissue typing laboratory on a monthly basis for crossmatching in the event of a cadaver donor. Therefore, it is essential there is consensus for results between these laboratories in order for donated organs to be allocated appropriately. A quality control program conducted under the auspices of ASEATTA was undertaken for (1) panel reactive antibody characterization; (2) routine T lymphocyte crossmatching; and (3) characterization of antibody isotype by DTT treatment. These aims were achieved by distribution of (1) six sera for the determination of PRA activity; (2) 20 scrambled trays including replicate dilutions of a strongly positive lymphocytotoxic serum, high titer monoclonal antibody and negative sera and; (3) 20 trays containing sera with IgG and/or IgM antibodies. These were then evaluated by each laboratory on a panel of T cells. There was concordance between laboratories for PRA levels and antibody characterization. However, there was considerable variation in crossmatch sensitivity and reproducibility, several laboratories had carryover and others could not detect weak IgM antibodies. These results demonstrate the utility and need for ongoing crossmatch exchange programs, particularly for laboratories participating in organ exchange programs.

The therapy of amblyopia: an analysis comparing the results of amblyopia therapy utilizing two pooled data sets

CONTEXT

We previously presented the results of an original pooled data set of 961 amblyopic patients who underwent patching therapy for amblyopia from 1965 to 1994 (study group 1). Three types of amblyopia were considered: anisometropic, anisometropic-strabismic, and strabismic. Analysis of this group's success was related to the age at which therapy was initiated, the type of amblyopia, and the depth of visual loss before treatment was begun. The purpose of the current study is to test the validity of these findings on a second group of 961 amblyopes employing the data set used by Woodruff and associates in their publications (study group 2). These 2 data sets, after adjustment to conform to the definitions of age, amblyopia, anisometropia, and similar items utilized in common between the 2 study groups, will be compared for the risk factors predictive of successful occlusion therapy.

OUTCOME

As in the previous study, the success of occlusion therapy is defined as a visual acuity of 20/40 or better at the end of treatment.

RESULTS

Success by the 20/40 criteria was achieved in 73.7% in study group 1 and in 59.9% in study group 2. By category, the rate of success in study group 1 was 77.2% in strabismic amblyopia, 67.2% in anisometropic-strabismic amblyopia, and 66.0% in anisometropic amblyopia. In study group 2, success was 61.2% in strabismic amblyopia, 51.2% in anisometropic-strabismic amblyopia, and 63.0% in anisometropic amblyopia. Study group 1 univariate analysis related success in each group to the age at which therapy was initiated, the type of amblyopia, and the depth of visual loss before treatment in each group. In study group 2, univariate analysis related success of occlusion therapy to age and the depth of visual loss before treatment. Type of amblyopia was not related to outcome success in this group. When the 2 data sets were pooled, the risk factors for success were age and depth of visual loss at onset of treatment.

CONCLUSIONS

Factors that appeared closely related to a successful outcome of patching therapy were patient age and depth of visual loss before treatment. These conclusions further support the value of early detection and screening for amblyopia, its prevention, where possible, and its adequate and vigorous treatment when it is detected and diagnosed.

Effectiveness of three different doses of carvedilol for exertional angina. Carvedilol-Angina Study Group

Carvedilol is a nonselective beta-receptor antagonist with vasodilating properties primarily due to selective alpha-1 antagonism. This 4-treatment, 5-period, double-blind, crossover study evaluated the efficacy and safety of 3 doses of carvedilol (12.5, 25, and 50 mg given twice daily) versus placebo in 122 patients with chronic stable angina. Carvedilol in doses of 25 mg twice daily and 50 mg twice daily was statistically superior to placebo with respect to time to angina (placebo: 316 seconds; 25 mg carvedilol: 337 seconds, p = 0.0039; 50 mg: 345 seconds, p <0.0001) and time to 1-mm ST-segment depression (placebo: 301 seconds; 25 mg: 313 seconds; 50 mg: 323 seconds; p <0.0001). The percentage of patients reporting any adverse experience was slightly less in those receiving placebo (placebo: 28.4%; 12.5 mg: 33.1%; 25 mg: 34.5%; 50 mg: 31.9%). Carvedilol is effective and safe in treating patients with chronic stable angina.

Mechanisms underlying the absence of the pubertal shift in the playful defense of female rats

Due to the action of testicular hormones in the perinatal period, juvenile male rats engage in more play fighting than juvenile females. Also, following puberty, males, but not females, switch to using adultlike defensive tactics more frequently during play. This change in play is also due to the action of testicular hormones perinatally. In this study, two experiments were conducted to determine if the pubertal transition in defense could be induced in females. For Experiment 1, male and female cagemates were tested before and after puberty with familiar and unfamiliar partners. Even when playfully interacting with subadult males, females did not increase the use of the adultlike defensive tactics. For Experiment 2, neonatal females were either injected with testosterone propionate (TP) or ovariectomized (OVX), and again tested before and after puberty. While the TP-treated females had higher frequencies of play fighting, they did not change their pattern of defense following puberty. The OVX females exhibited the lower frequency of play fighting typical of females, but changed their pattern of defense with increased age. Thus, it appears that the pattern of pubertal change in playful defense typical of males is inhibited by ovarian hormones. The mechanisms by which ovarian hormones could exert this effect on developing females are discussed.

Torsade de pointes resulting from the addition of droperidol to an existing cytochrome P450 drug interaction

OBJECTIVE

To report a case of QT prolongation associated with concomitant cyclobenzaprine and fluoxetine administration followed by torsade de pointes potentiated by droperidol.

CASE SUMMARY

A 59-year-old white woman who had been receiving long-term fluoxetine and cyclobenzaprine therapy was admitted for Achilles tendon repair. Baseline QTc was prolonged at 497 msec. Prior to surgery, the patient received droperidol, an agent known to prolong the QT interval. During surgery the patient developed torsade de pointes, which progressed into ventricular fibrillation. On postoperative day 1, after cyclobenzaprine discontinuation, the QTc decreased toward normal (440 msec).

DISCUSSION

Cyclobenzaprine shares anticholinergic effects, tachycardia, and dysrhythmic potential with the tricyclic antidepressants (TCAs). Fluoxetine is a known inhibitor of the CYP2D6 isoenzyme (along with CYP3A4 and CYP2C) and has been shown to increase TCA serum concentrations. The combination of cyclobenzaprine and fluoxetine resulted in significant QT prolongation in our patient that progressed to torsade de pointes after preoperative droperidol administration. Resolution of QT abnormalities after cyclobenzaprine discontinuation provided further evidence of a drug-induced etiology. Other possible medical and drug-related causes of torsade de pointes are reviewed and ruled out.

CONCLUSIONS

Clinicians should be aware of the dysrhythmic potential of cyclobenzaprine and fluoxetine, monitor for other cytochrome P450 inhibitors, and avoid concomitant drugs known to prolong the QT interval.

Emergency admissions of older people to hospital: a link with material deprivation

BACKGROUND

The aim was to investigate whether variations in emergency admission to hospital amongst older people in Leicestershire vary with the level of material deprivation of the area in which they live.

METHODS

Data were extracted from the Trent Patient Information System for patients aged 65 and over, admitted as an emergency medical admission to Leicestershire's acute and community hospitals on at least one occasion during the period October 1993-September 1994. The 1991 Census was used to examine the nature of the areas from which these emergency admissions were drawn and variations in emergency admission rates across Leicestershire. The relationship between emergency medical admissions and age, sex and material deprivation as measured by the Townsend deprivation score was examined.

RESULTS

There were 13,305 people aged 65 or over with at least one emergency medical admission out of an estimated population (65 and over) in 1994 of 134,608 (9.9 per cent). Unconditional logistic regression showed that the risk of emergency admission increased with age and was also higher for men than for women. Emergency admissions increased significantly with increasing deprivation for each age group. This was most notable in the 65-74 years age group, yielding an odds ratio of 2.06 [95 per cent confidence interval (1.86, 2.29)], when comparing those from the most deprived areas with those from the least deprived areas.

CONCLUSIONS

The increased risk of emergency medical admission to hospital, which is associated with residence in areas characterized as deprived by Census-based indicators, suggests there are enduring inequalities in health or health care amongst older people. Inequalities noted for all ages persist into old age, although in the 'oldest' age groups, the effect is weaker. Material deprivation may also be a proxy for other factors, such as differences in social support and the type of care received.

Comparison of the fixed combination of enalapril/diltiazem ER and their monotherapies in stage 1 to 3 essential hypertension

The safety and efficacy of two fixed dose combinations of enalapril and diltiazem extended release formation (ER) (E/D) were compared with their monotherapies and placebo in patients with stage 1 to 3 hypertension. The trial design was a multicenter, randomized, double blind, placebo controlled, parallel group, 12 week treatment phase, followed by a 36 week, open label phase. A total of 891 patients with sitting diastolic blood pressure (SiDBP) between 95 and 115 mm Hg were randomly assigned to enalapril 5 mg, diltiazem ER 120 mg, diltiazem ER 180 mg, enalapril 5 mg/diltiazem ER 120 mg (E5/D120), enalapril 5 mg/ diltiazem ER 180 mg (E5/D180), or placebo. In the open label phase, 562 patients received the fixed combination, titrated as needed to control SiDBP < 90 mm Hg. Efficacy was determined with trough (24 +/- 2 h postdose) sitting blood pressure measurements at week 12 and at the end of the open label part of the study. Safety was evaluated based on patient symptoms, clinical laboratories, and electrocardiograms (ECG). E5/D120 and E5/D180 significantly reduced trough SiDBP (-7.6 and -8.3 mm Hg, respectively; P < .05) versus their monotherapies. E5/D120 and E5/D180 significantly reduced trough sitting systolic blood pressure (-7.9 and -9.0, respectively; P < .05) versus both diltiazem ER monotherapies. All active treatments significantly decreased SiDBP and SiSBP versus placebo. E/D effectively lowered SiDBP and SiSBP during the open label extension. No significant difference was seen among treatment groups for the overall incidence of adverse events. The most common drug related adverse events were headache, edema/swelling, dizziness, asthenia/fatigue, cough, rash, and impotence. The event frequency for the combinations were similar to those seen with the monotherapies. Fixed combinations of E/D were generally well tolerated, with an increased blood pressure lowering effect as compared with the individual components in patients with stage I to III hypertension.

The postpubertal change in the playful defense of male rats depends upon neonatal exposure to gonadal hormones

The pattern of playful defense used during play fighting by male rats (Rattus norvegicus) castrated at birth was compared to that of sham-operated and untreated controls during the juvenile phase and after puberty. The neonatal castrates failed to exhibit the age-related changes in playful defense present in intact male rats of the same age. Following puberty, control rats, but not neonatal castrates, switched from juvenile to more adult-typical defensive tactics. That the neonatal castrations were effective was independently shown by the animals' failure to exhibit the asymmetries in weight and play behavior indicative of dominance-subordinance relationships present in normal adult males. A previous study found that castration following weaning did not prevent the pubertal change in playful defense, but did block the formation of dominance-subordinance relationships. Therefore, it appears that the age-related shift in playful defense is a feature of the development of play fighting in males that is likely preprogrammed by gonadal hormone exposure in the perinatal period.

Multiple differences in the play fighting of male and female rats. Implications for the causes and functions of play

Play fighting is the most commonly occurring form of social play in juvenile mammals. Typically, males engage in more play fighting than females, and this difference has been shown to depend on the action of androgens perinatally. It is generally believed that the differences in play fighting between the sexes are quantitative and do not involve qualitative differences in the behavior performed. We show that this is an incorrect characterization of sex difference in play fighting. For example, in laboratory rats, there are at least five different mechanisms that contribute to the observed sex differences in play fighting. These mechanisms involve (I) the motivation to initiate play, (II) the sensory capacity to detect and respond to a play partner, (III) the organization of the motor patterns used to interact with a partner, (IV) age-related changes at puberty in initiating play and in responding to playful contact, and (V) dominance-related changes in adulthood in the pattern of playful interaction. Sex differences in the play fighting of rats are due to an interaction of all of these mechanisms, some of which are sex-typical not play-typical, and involve both quantitative and qualitative differences. This is clearly different from the prevailing view that play fighting is a unitary behavior which is masculinized perinatally. Indeed, even though all five mechanisms are androgenized perinatally, the sensorimotor differences also involve defeminization (i.e. reduction of female-typical qualities). This expanded view of the mechanisms contributing to the sex differences in play fighting has implications for both the analysis of the neural systems involved, and for the functional significance of this activity in childhood and adulthood.

The insulin-induced down-regulation of IRS-1 in 3T3-L1 adipocytes is mediated by a calcium-dependent thiol protease

Insulin receptor substrate-1 (IRS-1) is a protein expressed in 3T3-L1 adipocytes that is involved in most, if not all of the biological responses to insulin. Chronic exposure of these cells to insulin down-regulates IRS-1 by stimulating its degradation (Rice, K.M., Turnbow, M.A. and Garner, C.W. (1993) Biochem. Biophys. Res. Commun. 190, 961-967). This insulin-induced down-regulation of IRS-1 was totally abolished by BAPTA-AM (cell-permeable calcium chelator), E-64d (cell-permeable thiol protease inhibitor), Cbz-Leu-Nleu-H and Cbz-Leu-Leu-Tyr-CHN2 (selective cell-permeable calpain inhibitor peptides). Calpastatin (specific calpain inhibitor protein) also inhibited the insulin-induced down-regulation of IRS-1 in transiently permeabilized cells. In addition, 3T3-L1 adipocytes express endogenous calpain which can degrade IRS-1 in cell-free extracts. These results suggest that the insulin-induced down-regulation of IRS-1 in 3T3-L1 adipocytes is mediated by a calcium-dependent thiol protease which is sensitive to inhibition by calpain inhibitors.

Cost and time savings following introduction of rejection criteria for clinical specimens

We have evaluated the yield of several tests and have instituted specimen rejection criteria to reduce costs and save time. For a 12-month period, we recorded the reduction of these tests and calculated the resultant cost and time savings. Seven changes were analyzed: not performing fungal or mycobacterial (acid-fast bacillus) cultures on cerebrospinal fluid (CSF) specimens from patients without known immunosuppression when chemistry and cell count are normal; not performing routine stool culture or ovum and parasite examination on specimens from patients in the hospital for > 3 days; not culturing endotracheal suction aspirates when no organisms or > 10 squamous epithelial cells are present; discontinuing broth cultures on all specimens except for tissue, continuous ambulatory peritoneal dialysis fluid, and CSF from patients with shunts; and eliminating bacterial antigen tests. For each test, the number not performed (n), reagent savings, and technologist time saved, respectively, were as follows: CSF fungal culture, 267, $999, and 67 h; CSF acid-fast bacillus culture, 275, $1,662, and 124 h; stool cultures, 320, $2,991, and 98 h; ovum and parasite examinations, 216, $525, and 108 h; endotracheal suction aspirate cultures, 1,505, $4,447, and 306 h; broth cultures, 5,218, $4,931, and 80 h; and bacterial antigen tests, 2,598, $2,293, and 299 h. Overall, 5,181 tests were rejected and 5,218 broth cultures were omitted. Achievable savings were $28,000 in reagent costs and 1,082 h of technologist time. In conclusion, rejecting specimens of proven low yield saves reagent costs and, more importantly, saves technologist time. This time can be spent on specimens having greater diagnostic utility.

Functional improvements following StairMaster vs. treadmill exercise training for patients with intermittent claudication

BACKGROUND

Although there have been many studies showing that exercise training is beneficial for patients with peripheral vascular occlusive disease (PVOD), there is little research comparing various modes of training. Previous studies showed that exercise tests performed on a StairMaster (StairMaster Sports/Medical Products, Kirkland, WA) produce responses similar to those elicited by treadmill tests. The purpose of this study was to compare these modes of exercise in a training program for patients with PVOD.

METHODS

Of the 23 eligible individuals who began the exercise program, 11 did not complete the regimen due to various complications. Thus, 12 patients were randomly assigned to train for 12 weeks on either a StairMaster (n = 6) or a treadmill (n = 6). Patients underwent progressive and single-stage exercise tests on both exercise modalities before and after training.

RESULTS

Mean exercise time before the onset of claudication pain for all tests rose significantly after training (P <.01), but greater improvements were seen on the specific training apparatus (i.e., treadmill training resulted in improvement in treadmill exercise performance with less improvement noted when tested on the StairMaster, and vice versa). Exercise time to maximal pain increased for the training apparatus only (P <.01). There were no changes in foot transcutaneous oxygen tension or the ankle-brachial blood pressure index.

CONCLUSIONS

Both StairMaster and treadmill training improve the exercise capacity of PVOD patients. The training effect is most apparent for the specific training apparatus, but there is some cross-over improvement to the other exercise modality. Thus, StairMaster training is appropriate and can be part of the exercise prescription for treatment of these patients.

Children's vision screening: impact on inequalities in central England

STUDY OBJECTIVE

To investigate the relationship between age at presentation of amblyopia and social deprivation before and after the introduction of changes to a vision screening service.

DESIGN

Two cohorts of children treated for amblyopia in 1983 and 1992.

SETTING

THe orthoptic department of Leicester Royal Infirmary.

PARTICIPANTS

The 209 patients treated for amblyopia who first attended the orthoptic department in 1983, and 203 who first attended in 1992.

MEASUREMENTS

Age at presentation to the orthoptic department was the main outcome measure. Social deprivation was measured by Townsend deprivation score for the electoral ward in which the child lived, using 1981 and 1991 census data.

MAIN RESULTS

After the introduction of changes in the screening programme, the mean at presentation of amblyopia associated with microtropia or no strabismus was reduced from 6.6 years to 5.0 years. In 1983 there was a significant relationship between deprivation and age at presentation (p = 0.0001), with those from more deprived areas presenting later. No similar association was found in children referred in 1992 (p = 0.17). There was no change in mean age of presentation of amblyopia associated with a large angle of strabismus (3.3 years in 1983 and 1992) and no relationship between deprivation and age at presentation 1983 or 1992 (p = 0.24 and p = 0.39 respectively).

CONCLUSION

Since the introduction of changes to vision screening, the relationship between social deprivation and the age of presentation of asymptomatic amblyopia seems to have disappeared. Children are now referred earlier and those from deprived areas are not being overlooked.

Cardiac rehabilitation as secondary prevention. Agency for Health Care Policy and Research and National Heart, Lung, and Blood Institute

This Quick Reference Guide for Clinicians highlights the conclusions and recommendations from Cardiac Rehabilitation, Clinical Practice Guideline No. 17, which was formulated by a panel representing the major health care disciplines involved in cardiac rehabilitation. The conclusions and recommendations were derived from an extensive and critical review of the scientific literature pertaining to cardiac rehabilitation, as well as from the expert opinion of the panel. This guide addresses the role of cardiac rehabilitation and the potential benefits to be derived in the comprehensive care of the 13.5 million patients with heart disease in the United States, as well as the 4.7 million patients with heart failure and the several thousand patients undergoing heart transplantation. This Quick Reference Guide for Clinicians highlights the major effects of multifactorial cardiac rehabilitation services: medical evaluation; prescribed exercise; cardiac risk factor modification; and education, counseling, and behavioral interventions. The outcomes of and recommendations for cardiac rehabilitation services are categorized as to their effects on exercise tolerance, strength training, exercise habits, symptoms, smoking, lipids, body weight, blood pressure, psychological well-being, social adjustment and functioning, return to work, morbidity and safety issues, mortality and safety issues, and pathophysiologic measures. Patients with heart failure and after cardiac transplantation, as well as elderly patients, are specifically addressed. Alternate approaches to the delivery of cardiac rehabilitation services are presented.

Wortmannin and LY294002 inhibit the insulin-induced down-regulation of IRS-1 in 3T3-L1 adipocytes

The insulin receptor substrate-1 (IRS-1) is expressed in 3T3-L1 adipocytes and is involved in at least some insulin responses, notably mitogenesis. Chronic exposure to insulin down regulates IRS-1 in these cells by stimulating its degradation (Rice, K.M., Turnbow, M.A. and Garner, C.W. (1993) Biochem. Biophys. Res. Commun. 190, 961-967). This insulin response was completely inhibited by wortmannin and LY294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one), two inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase). Neither wortmannin nor LY294002 had any effect on the calcium-dependent degradation of IRS-1 in vitro nor did they inhibit the phosphorylation of IRS-1 in vitro. In addition, neomycin, a cationic aminoglycoside antibiotic that binds to phosphoinositides, inhibited the insulin-induced down-regulation of IRS-1 in 3T3-L1 adipocytes and, also, the C8-PIP3-stimulated degradation of IRS-1 in vitro. These results suggest that PI 3-kinase and its 3-phosphoinositide products mediate the insulin-induced down-regulation of IRS-1 in 3T3-L1 adipocytes.

Parents' views of health surveillance

The aim of the study was to discover the views of parents about the 1991 Leicestershire child health surveillance programme, its organisation, and content. The study design was a postal questionnaire survey to parents of a sample of children eligible for the new surveillance programme. One thousand parents received questionnaires, of which 66% (660) were returned. Poor access for prams and wheelchairs (595 responses) and inadequate general cleanliness (249 responses) caused most criticism of clinic premises. The experiences of parents from ethnic minorities were significantly worse for some professional consultation factors, but they received significantly more health advice than other parents. Parents lacked sufficient information about the surveillance programme and their most frequent reasons for non-attendance were time related factors. Minimum standards for child health surveillance premises are required. At present, many fail to reach adequate standards of privacy and accessibility. Schemes to ensure an equal partnership in child health surveillance between parents and professionals are essential.

The oxazolidinedione CP-92,768-2 partially protects insulin receptor substrate-1 from dexamethasone down-regulation in 3T3-L1 adipocytes

Oxazolidinediones are a class of oral antidiabetic agents that are closely related structurally and pharmacologically to thiazolidinediones. The thiazolidinediones have been shown to partially reverse the loss in insulin-responsive glucose uptake caused by chronic treatment with dexamethasone. This study was conducted to determine certain aspects of the mechanism of thiazolidinedione and oxazolidinedione action. We selected the oxazolidinedione CP-92,768-2 (5-[2-[(5-methyl2-phenyl-4-oxazolyl)methyl]5-benzofuranyl methyl]2,4- oxazolidinedione) to determine whether these agents could reverse the dexamethasone-induced down-regulation of IRS-1, the insulin receptor substrate-1. In 3T3-L1 adipocytes, dexamethasone treatment resulted in down-regulation of IRS-1 to 60% of control values. Simultaneous treatment with CP-92,768-2 significantly increased IRS-1 to 78% of the control value (EC50, < 10 nM), although it did not completely reverse the dexamethasone effect at any concentration tested. CP-92,768-2 alone did not have any effect on IRS-1. CP-92,768-2 did not affect the stability of IRS-1 protein in the presence or absence of dexamethasone, as measured by [35S]methionine pulse-chase labeling. Dexamethasone decreased messenger RNA (mRNA) for IRS-1 after 24 h of treatment to 40% of the control value. CP-92,768-2 partially reversed this decrease in IRS-1 mRNA to 65% of the control value after 24 h of treatment, but had no effect on IRS-1 mRNA in the absence of dexamethasone. Dexamethasone down-regulated the insulin stimulation of [3H]thymidine incorporation to 68% of the control value. Dexamethasone in the presence of CP-92,768-2 down-regulated insulin stimulation of thymidine incorporation by only 9%. Dexamethasone also down-regulated the expression of phosphoenolpyruvate carboxykinase (PEPCK) protein by 50%. CP-92,768-2 partially protected PEPCK from the dexamethasone down-regulation. Conversely, the up-regulation of expression of PEPCK and IRS-1 produced by dexamethasone in KRC-7 hepatoma cells was not affected by CP-92,768-2. One contribution of oxazolidinediones to an increase in insulin responsiveness in the presence of glucocorticoids may be the up-regulation of IRS-1 in adipose cells.

Factors affecting treatment compliance in amblyopia

Amblyopia is the most common form of visual disability in children. Successful treatment by patching depends on compliance, but evidence of factors affecting compliance is limited and contradictory. Because there is a well established relationship between social deprivation and access to health care, we hypothesized that social deprivation might be associated with noncompliance. Data from a historical cohort of 961 children from seven English orthoptic clinics starting treatment for amblyopia in 1983 were used to study factors affecting compliance with amblyopia treatment. Children were classified as noncompliant if they failed to attend all appointments prescribed during the first year of treatment. There was a significant difference in compliance between centers (P = .0001). Overall, children with anisometropic amblyopia were more compliant than those with strabismus but this varied significantly between centers. A relationship between social deprivation and compliance was also found (P = .00001). Only 41% of children from the most deprived wards were compliant compared with 61% in the least deprived wards. Compliance was not found to be related to age at starting treatment.

Matching for MHC haplotypes results in improved survival following unrelated bone marrow transplantation

Unrelated bone marrow donor-recipient pairs were assessed retrospectively for matching of the HLA-B, -C region (beta-block) and HLA-DR, DQ region (delta block) of the major histocompatibility complex (MHC) using a new DNA-based method referred to as MHC-block typing. The method utilises non-HLA DNA polymorphisms in the MHC as markers of blocks of ancestral haplotypes. Kaplan-Meier analysis of recipients who were matched at both the beta- and delta-blocks revealed a 6 months survival of 54%. Survival was better than for patients who were matched only by conventional criteria, including SSO-typing for class II.