Discovery and Characterization of a Bicyclic Peptide (Bicycle) Binder to Thymic Stromal Lymphopoietin

Thymic stromal lymphopoietin (TSLP) is an epithelial-derived pro-inflammatory cytokine involved in the development of asthma and other atopic diseases. We used Bicycle Therapeutics' proprietary phage display platform to identify bicyclic peptides (Bicycles) with high affinity for TSLP, a target that is difficult to drug with conventional small molecules due to the extended protein-protein interactions it forms with both receptors. The hit series was shown to bind to TSLP in a hotspot, that is also used by IL-7Rα. Guided by the first X-ray crystal structure of a small peptide binding to TSLP and the identification of key metabolites, we were able to improve the proteolytic stability of this series in lung S9 fractions without sacrificing binding affinity. This resulted in the potent Bicycle 46 with nanomolar affinity to TSLP (KD = 13 nM), low plasma clearance of 6.4 mL/min/kg, and an effective half-life of 46 min after intravenous dosing to rats.

How well does molecular simulation reproduce environment-specific conformations of the intrinsically disordered peptides PLP, TP2 and ONEG?

Understanding the conformational ensembles of intrinsically disordered proteins and peptides (IDPs) in their various biological environments is essential for understanding their mechanisms and functional roles in the proteome, leading to a greater knowledge of, and potential treatments for, a broad range of diseases. To determine whether molecular simulation is able to generate accurate conformational ensembles of IDPs, we explore the structural landscape of the PLP peptide (an intrinsically disordered region of the proteolipid membrane protein) in aqueous and membrane-mimicking solvents, using replica exchange with solute scaling (REST2), and examine the ability of four force fields (ff14SB, ff14IDPSFF, CHARMM36 and CHARMM36m) to reproduce literature circular dichroism (CD) data. Results from variable temperature (VT) 1H and Rotating frame Overhauser Effect SpectroscopY (ROESY) nuclear magnetic resonance (NMR) experiments are also presented and are consistent with the structural observations obtained from the simulations and CD. We also apply the optimum simulation protocol to TP2 and ONEG (a cell-penetrating peptide (CPP) and a negative control peptide, respectively) to gain insight into the structural differences that may account for the observed difference in their membrane-penetrating abilities. Of the tested force fields, we find that CHARMM36 and CHARMM36m are best suited to the study of IDPs, and accurately predict a disordered to helical conformational transition of the PLP peptide accompanying the change from aqueous to membrane-mimicking solvents. We also identify an α-helical structure of TP2 in the membrane-mimicking solvents and provide a discussion of the mechanistic implications of this observation with reference to the previous literature on the peptide. From these results, we recommend the use of CHARMM36m with the REST2 protocol for the study of environment-specific IDP conformations. We believe that the simulation protocol will allow the study of a broad range of IDPs that undergo conformational transitions in different biological environments.

Exposure to risperidone versus other antipsychotics and risk of osteoporosis-related fractures: a population-based study

OBJECTIVE

Antipsychotics may increase serum prolactin, which has particularly been observed with risperidone. Further, hyperprolactinemia has been linked to osteoporosis-related fractures. Therefore, we investigated fracture risk in a nationwide cohort exposed to antipsychotics.

METHODS

Swedish registers were used to identify adults with two consecutive dispensations of risperidone (n = 38 211), other atypical antipsychotics not including paliperidone (n = 60 691), or typical antipsychotics (n = 17 445) within three months between 2006 and 2013. An osteoporosis-related fracture was defined as a non-open hip/femur fracture in primary analyses. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Risperidone users were on average older (mean age of 68, 44, and 63 years for risperidone, other atypical antipsychotics, and typical antipsychotics respectively). Compared with other atypical antipsychotics, there was no association between risperidone and osteoporosis-related fractures in the overall (HR = 1.04, CI: 0.91-1.19) or age-stratified analyses. A significantly increased risk of typical antipsychotics (HR = 1.24, CI: 1.07-1.45) compared with other atypical antipsychotics remained for ages >45 years.

CONCLUSION

Risperidone does not appear to be associated with an increased risk of osteoporosis-related fracture compared with other atypical antipsychotic agents as a group. For typical antipsychotics, a moderately elevated risk of hip fractures was noted compared with other atypical antipsychotics, possibly because of residual confounding.

Invasive Dental Treatment and Risk for a First Myocardial Infarction

Invasive dental treatment is suggested to be associated with an increased risk for the development of cardiovascular events. We tested the hypothesis that the incidence of a first myocardial infarction (MI) within 4 wk after invasive dental treatments is increased. A registry-based case-control study within nationwide health care and population registries in Sweden was performed. The case patients included 51,880 individuals with a first fatal or nonfatal MI between January 2011 and December 2013. For each case, 5 control subjects, free from prior MI and matched for age, sex, and geographic area of residence, were randomly selected from the national population registry through risk set sampling with replacement, resulting in 246,978 control subjects. Information on dental treatments was obtained from the Dental Health Register, and the procedures were categorized into invasive dental treatments or other dental treatments. Conditional logistic regression was used to estimate odds ratios (ORs) for MI with corresponding 95% confidence intervals (CIs). In addition to the matching variables, adjustments were made for the following confounders: diabetes, previous cardiovascular disease (CVD), CVD drug treatment, education, and income. The mean age for case patients and controls subjects was 72.6 ± 13.0 y and 72.3 ± 13.0 y, respectively. Case patients more often had previous CVD (49% vs. 23%; P < 0.001) and diabetes (19% vs. 11%; P < 0.001) and received more treatment with CVD drugs (68% vs. 56%; P < 0.001) than control subjects. There was no association between invasive dental treatments during the 4 wk preceding the MI index date (crude OR = 0.99; 95% CI, 0.92 to 1.06; adjusted for confounders OR = 0.98; 95% CI, 0.91 to 1.06). This study did not support the hypothesis of an increased incidence of MI after recent invasive dental treatment.

Temperature-controlled airflow ventilation in operating rooms compared with laminar airflow and turbulent mixed airflow

AIM

To evaluate three types of ventilation systems for operating rooms with respect to air cleanliness [in colony-forming units (cfu/m³)], energy consumption and comfort of working environment (noise and draught) as reported by surgical team members.

METHODS

Two commonly used ventilation systems, vertical laminar airflow (LAF) and turbulent mixed airflow (TMA), were compared with a newly developed ventilation technique, temperature-controlled airflow (T_cAF). The cfu concentrations were measured at three locations in an operating room during 45 orthopaedic procedures: close to the wound (<40cm), at the instrument table and peripherally in the room. The operating team evaluated the comfort of the working environment by answering a questionnaire.

FINDINGS

LAF and T_cAF, but not TMA, resulted in less than 10cfu/m³ at all measurement locations in the room during surgery. Median values of cfu/m³ close to the wound (250 samples) were 0 for LAF, 1 for T_cAF and 10 for TMA. Peripherally in the room, the cfu concentrations were lowest for T_cAF. The cfu concentrations did not scale proportionally with airflow rates. Compared with LAF, the power consumption of T_cAF was 28% lower and there was significantly less disturbance from noise and draught.

CONCLUSION

T_cAF and LAF remove bacteria more efficiently from the air than TMA, especially close to the wound and at the instrument table. Like LAF, the new T_cAF ventilation system maintained very low levels of cfu in the air, but T_cAF used substantially less energy and provided a more comfortable working environment than LAF. This enables energy savings with preserved air quality.

The continuous reaction time test for minimal hepatic encephalopathy validated by a randomized controlled multi-modal intervention-A pilot study

Background

Minimal hepatic encephalopathy (MHE) is clinically undetectable and the diagnosis requires psychometric tests. However, a lack of clarity exists as to whether the tests are in fact able to detect changes in cognition.

Aim

To examine if the continuous reaction time test (CRT) can detect changes in cognition with anti-HE intervention in patients with cirrhosis and without clinically manifest hepatic encephalopathy (HE).

Methods

Firstly, we conducted a reproducibility analysis and secondly measured change in CRT induced by anti-HE treatment in a randomized controlled pilot study: We stratified 44 patients with liver cirrhosis and without clinically manifest HE according to a normal (n = 22) or abnormal (n = 22) CRT. Each stratum was then block randomized to receive multimodal anti-HE intervention (lactulose+branched-chain amino acids+rifaximin) or triple placebos for 3 months in a double-blinded fashion. The CRT is a simple PC-based test and the test result, the CRT index (normal threshold > 1.9), describes the patient’s stability of alertness during the 10–minute test. Our study outcome was the change in CRT index in each group at study exit. The portosystemic encephalopathy (PSE) test, a paper-and-pencil test battery (normal threshold above -5), was used as a comparator test according to international guidelines.

Results

The patients with an abnormal CRT index who were randomized to receive the active intervention normalized or improved their CRT index (mean change 0.92 ± 0.29, p = 0.01). Additionally, their PSE improved (change 3.85 ± 1.83, p = 0.03). There was no such effect in any of the other study groups.

Conclusion

In this cohort of patients with liver cirrhosis and no manifest HE, the CRT identified a group in whom cognition improved with intensive anti-HE intervention. This finding infers that the CRT can detect a response to treatment and might help in selecting patients for treatment.

High serum total cholesterol is associated with suicide mortality in Japanese women

OBJECTIVE

To investigate the association between serum total cholesterol (TC) and suicide using a large general population cohort with long follow-up times.

METHOD

Analyses included 16 341 men and 28 905 women aged 40-69 from the Japan Public Health Center-based Prospective Study followed from 1990 to 2012. TC levels were defined per clinical guidelines: low (<4.66 mmol/l [180 mg/dl]), normal (4.66-5.70 mmol/l [180-220 mg/dl]), and high (≥5.70 mmol/l [220 mg/dl]). Cox proportional hazards regression models were used to determine hazard ratios (HR) and confidence intervals (CI) for suicide according to TC level. Mean follow-up time was 19 years for men and 20 years for women.

RESULTS

There were 185 suicides (men: 107; women: 78) during follow-up. Compared to women with normal TC, women with high TC had a significantly increased risk of suicide (HR = 1.90, 95% CI, 1.13-3.19). Incremental increases (0.26 mmol/l [10 mg/dl]) of low-density lipoprotein (HR = 1.11, 95% CI, 1.02-1.21) and non-high-density lipoprotein cholesterol (HR = 1.09, 95% CI, 1.01-1.18) were also associated with increased risk of suicide in women. There was no association between TC levels, or lipid fractions, and suicide in men.

CONCLUSION

High TC levels may be associated with an increased risk of suicide in women.

Design and Synthesis of Soluble and Cell-Permeable PI3Kδ Inhibitors for Long-Acting Inhaled Administration

PI3Kδ is a lipid kinase that is believed to be important in the migration and activation of cells of the immune system. Inhibition is hypothesized to provide a powerful yet selective immunomodulatory effect that may be beneficial for the treatment of conditions such as asthma or rheumatoid arthritis. In this work, we describe the identification of inhibitors based on a thiazolopyridone core structure and their subsequent optimization for inhalation. The initially identified compound (13) had good potency and isoform selectivity but was not suitable for inhalation. Addition of basic substituents to a region of the molecule pointing to solvent was tolerated (enzyme inhibition pIC₅₀ > 9), and by careful manipulation of the pK_a and lipophilicity, we were able to discover compounds (20b, 20f) with good lung retention and cell potency that could be taken forward to in vivo studies where significant target engagement could be demonstrated.

Loss of a close family member the year before or during pregnancy and the risk of placental abruption: a cohort study from Denmark and Sweden

BACKGROUND

Maternal stress during pregnancy is associated with a modestly increased risk of fetal growth restriction and pre-eclampsia. Since placental abruption shares similar pathophysiological mechanisms and risk factors with fetal growth restriction and pre-eclampsia, we hypothesized that maternal stress may be implicated in abruption risk. We investigated the association between maternal bereavement during pregnancy and placental abruption.

METHOD

We studied singleton births in Denmark (1978-2008) and Sweden (1973-2006) (n = 5,103,272). In nationwide registries, we obtained data on death of women's close family members (older children, siblings, parents, and partners), abruption and potential confounders.

RESULTS

A total of 30,312 (6/1000) pregnancies in the cohort were diagnosed with placental abruption. Among normotensive women, death of a child the year before or during pregnancy was associated with a 54% increased odds of abruption [95% confidence interval (CI) 1.30-1.82]; the increased odds were restricted to women who lost a child the year before or during the first trimester in pregnancy. In the group with chronic hypertension, death of a child the year before or in the first trimester of pregnancy was associated with eight-fold increased odds of abruption (odds ratio 8.17, 95% CI 3.17-21.10). Death of other relatives was not associated with abruption risk.

CONCLUSIONS

Loss of a child the year before or in the first trimester of pregnancy was associated with an increased risk of abruption, especially among women with chronic hypertension. Studies are needed to investigate the effect of less severe, but more frequent, sources of stress on placental abruption risk.

Design and synthesis of conformationally restricted inhibitors of active thrombin activatable fibrinolysis inhibitor (TAFIa)

A series of 4,5,6,7-tetrahydro-1H-benzimidazole-5-carboxylic acid and 5,6,7,8-tetrahydroimidazo[1,2-a]pyridine-7-carboxylic acid derivatives designed as inhibitors of TAFIa has been prepared via a common hydrogenation-alkylation sequence starting from the appropriate benzimidazole and imidazopyridine system. We present a successful design strategy using a conformational restriction approach resulting in potent and selective inhibitors of TAFIa. The X-ray structure of compound 5 in complex with a H333Y/H335Q double mutant TAFI indicate that the conformational restriction is responsible for the observed potency increase.

Use of serotonin reuptake inhibitors in patients with psoriasis is associated with a decreased need for systemic psoriasis treatment: a population-based cohort study

OBJECTIVE

To investigate whether psoriasis is affected by the use of serotonin reuptake inhibitors (SSRIs).

DESIGN

A population-based cohort study.

SETTING

The general adult population with plaque psoriasis in Sweden between 1997 and 2006.

SUBJECTS

A total of 69 830 patients with plaque psoriasis were identified in the National Patient Register. Whether study subjects were exposed to SSRIs was identified through the Swedish Prescribed Drug Register. The SSRI-exposed subjects (n = 1282) had a prescription for SSRIs dispensed twice during 6 months at a Swedish pharmacy between 1 July 2006 and 1 April 2008, with a wash-out period of 1 year or longer. The reference subjects (n = 1282), who were not exposed to SSRIs, were matched for age, county of residence, sex, psoriasis severity and seasonal variation.

MAIN OUTCOME MEASURE

Change in psoriasis severity defined by switching between nonsystemic and systemic psoriasis treatments 6 months after exposure to SSRIs.

RESULTS

The risk of switching from nonsystemic to systemic psoriasis treatments was significantly decreased in the SSRI-exposed group (odds ratio 0.44, 95% confidence interval 0.28-0.68).

CONCLUSION

SSRI use in patients with psoriasis is associated with a decreased need for systemic psoriasis treatment.

Exploiting breakdown of the similarity relation for diffuse light transport: simultaneous retrieval of scattering anisotropy and diffusion constant

As manifested in the similarity relation of diffuse light transport, it is difficult to assess single scattering characteristics from multiply scattered light. We take advantage of the limited validity of the diffusion approximation of light transport and demonstrate, experimentally and numerically, that even deep into the multiple scattering regime, time-resolved detection of transmitted light allows simultaneous assessment of both single scattering anisotropy and scattering mean free path, and therefore also macroscopic parameters like the diffusion constant and the transport mean free path. This is achieved via careful assessment of early light and matching against Monte Carlo simulations of radiative transfer.

Non-invasive diagnostics of the maxillary and frontal sinuses based on diode laser gas spectroscopy

PROBLEM

Suspected, but objectively absent, rhinosinusitis constitutes a major cause of visits to the doctor, high health care costs, and the over-prescription of antibiotics, contributing to the serious problem of resistant bacteria. This situation is largely due to a lack of reliable and widely applicable diagnostic methods.

METHOD

A novel method for the diagnosis of rhinosinusitis based on non-intrusive diode laser gas spectroscopy is presented. The technique is based on light absorption by free gas (oxygen and water vapour) inside the sinuses, and has the potential to be a complementary diagnostic tool in primary health care. The method was evaluated on 40 patients with suspected sinus problems, referred to the diagnostic radiology clinic for low-dose computed tomography (CT), which was used as the reference technique.

MAIN RESULTS

The data obtained with the new laser-based method correlated well with the grading of opacification and ventilation using CT. The sensitivity and specificity were estimated to be 93% and 61%, respectively, for the maxillary sinuses, and 94% and 86%, respectively, for the frontal sinuses. Good reproducibility was shown.

PRINCIPAL CONCLUSION

The laser-based technique presents real-time clinical data that correlate well to CT findings, while being non-intrusive and avoiding the use of ionizing radiation.

The genetic influence on diverticular disease--a twin study

BACKGROUND

The contribution of hereditary factors to the development of diverticular disease (DD) of the colon is unknown. Prevalence and location of diverticula differ in Western world compared to in Asia and several case reports describing families with DD have been published.

AIM

To assess the heritability of DD in a large population-based sample of twins.

METHODS

The Swedish Twin Registry was cross-linked to the Swedish Inpatient Registry. All twins, born between 1886 and 1980 and not dead before 1969, with a discharge diagnosis of DD were identified. Twins with diagnoses of colon cancer, coeliac disease or non-infectious colitis were excluded to decrease bias. Co-twin odds ratio (OR), concordance rates and tetrachoric correlations were calculated for monozygotic (MZ) and same gender-dizygotic (SS-DZ) twins. Mx-analyses were used to estimate the relative contributions of genetic effects and environmental factors to susceptibility for DD. Calculations were based on both primary and secondary discharge diagnoses to provide estimates reflecting impact of severity of the disease.

RESULTS

A total of 104,452 twins met the inclusion criteria. Of these, 2296 had a diagnosis of DD. The OR of developing the disease given one's co-twin was affected was 7.15 (95% CI: 4.82-10.61) for MZ and 3.20 (95% CI: 2.21-4.63) for SS-DZ twins. Similarly, concordance rates and tetrachoric correlations were higher in MZ than those in SS-DZ twins. The heritability was estimated to 40% and the non shared environmental effects to 60%.

CONCLUSION

Genetic susceptibility is an important component, along with individual specific environmental factors, for the development of diverticular disease of the colon.

Evaluation of prevalent and incident ovarian cancer co-morbidity

BACKGROUND

The peak in incidence of ovarian cancer occurs around 65 years and concurrent increasing risk by age for a number of diseases strongly influence treatment and prognosis. The aim was to explore prevalence and incidence of co-morbidity in ovarian cancer patients compared with the general population.

METHODS

The study population was patients with ovarian cancer in Sweden 1993-2006 (n=11 139) and five controls per case (n=55 687). Co-morbidity from 1987 to 2006 was obtained from the Swedish Patient Register. Prevalent data were analysed with logistic regression and incident data with Cox proportional hazards models.

RESULTS

Women developing ovarian cancer did not have higher overall morbidity than other women earlier than 3 months preceding cancer diagnosis. However, at time of diagnosis 11 of 13 prevalent diagnosis groups were more common among ovarian cancer patients compared with controls. The incidence of many common diagnoses was increased several years following the ovarian cancer and the most common diagnoses during the follow-up period were thromboembolism, haematologic and gastrointestinal complications.

CONCLUSION

Women developing ovarian cancer do not have higher overall morbidity the years preceding cancer diagnosis. The incidence of many common diagnoses was increased several years following the ovarian cancer. It is crucial to consider time between co-morbidity and cancer diagnosis to understand and interpret associations.

Diverticular disease and the risk of colon cancer - a population-based case-control study

BACKGROUND

Colon cancer and diverticular disease are most common in the Western world and their incidences tend to increase with advancing age. The association between the diseases remains unclear.

AIM

To analyse the risk of colon cancer after hospitalisation for diverticular disease.

METHODS

Nationwide case-control study. A total of 41,037 patients with colon cancer during 1992-2006, identified from the Swedish Cancer Register were included. Each case was matched with two control subjects. From the Swedish Inpatient Register, cases and control subjects hospitalised for diverticular disease were identified. Odds ratios (OR) and confidence intervals for receiving a diagnosis of colon cancer after hospital discharge for diverticular disease were calculated. Colon cancer mortality was compared between patients with or without diverticular disease.

RESULTS

Within 6months after an admission due to diverticular disease, OR of having a colon cancer diagnosis were up to 31.49 (19.00-52.21). After 12 months, there was no increased risk. The number of discharges for diverticular disease did not affect the risk. Colon cancer mortality did not differ between patients with and without diverticular disease.

CONCLUSIONS

Diverticular disease does not increase the risk of colon cancer in the long term, and a history of diverticular disease does not affect colon cancer mortality. The increased risk of colon cancer within the first 12months after diagnosing diverticular disease is most likely due to surveillance and misclassification. Examination of the colon should be recommended after a primary episode of symptomatic diverticular disease.

Suppression of high-p{T} neutral pion production in central Pb+Pb collisions at sqrt[S{NN}]=17.3 GeV relative to p+C and p+Pb collisions

Neutral pion transverse momentum spectra were measured in p+C and p+Pb collisions at sqrt[S{NN}]=17.4 GeV at midrapidity (2.3 less than or approximately equal eta{lab} less than or approximately equal 3.0) over the range 0.7 less than or approximately equal p{T} less than or approximately equal 3.5 GeV/c. The spectra are compared to pi{0} spectra measured in Pb+Pb collisions at sqrt[S{NN}]=17.3 GeV in the same experiment. For a wide range of Pb+Pb centralities (N{part} less than or approximately equal 300), the yield of pi{0}'s with p{T} greater than or approximately equal 2 GeV/c is larger than or consistent with the p+C or p+Pb yields scaled with the number of nucleon-nucleon collisions (N{coll}), while for central Pb+Pb collisions with N{part}greater than or approximately equal 350, the pi{0} yield is suppressed.

Intravenous hypertonic NaCl acts via cerebral sodium-sensitive and angiotensinergic mechanisms to improve cardiac function in haemorrhaged conscious sheep

Acute NaCl loading as resuscitation in haemorrhagic hypovolaemia is known to induce rapid cardiovascular recovery. Besides an osmotically induced increase in plasma volume the physiological mechanisms of action are unknown. We hypothesized that a CNS mechanism, elicited by increased periventricular [Na(+)] and mediated by angiotensin II type 1 receptors (AT(1)), is obligatory for the full effect of hypertonic NaCl. To test this we investigated the cardiovascular responses to haemorrhage and subsequent hypertonic NaCl infusion (7.5% NaCl, 4 ml (kg BW)(-1)) in six conscious sheep subjected to intracerebroventricular (i.c.v.) infusion of artificial cerebrospinal fluid (aCSF; control), mannitol solution (Man; 75 mmol l(-1) [Na(+)], total osmolality 295 mosmol kg(-1)) or losartan (Los; 1 mg ml(-1), AT(1) receptor antagonist) at three different occasions. Man normalized (144 +/- 6 mmol l(-1), mean +/- s.d.) the increase in i.c.v. [Na(+)] seen after aCSF (161 +/- 2 mmol l(-1)). Compared with control, both Man and Los significantly (P < 0.05) attenuated the improvement in mean arterial blood pressure (MAP), cardiac index and mesenteric blood flow (SMBF) in response to intravenous hypertonic NaCl: MAP, rapid response +45 mmHg versus +38 mmHg (Man) and +35 mmHg (Los); after 180 min, +32 mmHg versus +21 mmHg (Man) and +19 mmHg (Los); cardiac index after 180 min, +1.9 l min(-1) (m(2))(-1) versus +0.9 l min(-1) (m(2))(-1) (Man) and +0.9 l min(-1) (m(2))(-1) (Los); SMBF rapid response, +981 ml min(-1) versus +719 ml min(-1) (Man) and +744 ml min(-1) (Los); after 180 min, +602 ml min(-1) versus +372 ml min(-1) (Man) and +314 ml min(-1) (Los). The results suggest that increased periventricular [Na(+)] and cerebral AT(1) receptors contribute, together with plasma volume expansion, to improve systemic haemodynamics after treatment with hypertonic NaCl in haemorrhagic hypovolaemia.

Structure–activity relationships for the linker in a series of pyridinyl-alkynes that are antagonists of the metabotropic glutamate receptor 5 (mGluR5)

Studies of structure-activity relationships for the linker in a new series of metabotropic glutamate receptor 5 antagonists are presented together with in vitro and in vivo pharmacokinetic data.

A new series of pyridinyl-alkynes as antagonists of the metabotropic glutamate receptor 5 (mGluR5)

Synthesis and some structure-activity relationships for a new series of propargyl ethers as mGluR5 antagonists are reported.

Interferometry of direct photons in central 208Pb + 208Pb collisions at 158A GeV

Two-particle correlations of direct photons were measured in central 208Pb+208Pb collisions at 158A GeV. The invariant interferometric radii were extracted for 100<K(T)<300 MeV/c and compared to radii extracted from charged pion correlations. The yield of soft direct photons, K(T)<300 MeV/c, was extracted from the correlation strength and compared to theoretical calculations.

The gender differences in growth hormone-binding protein and leptin persist in 80-year-old men and women and is not caused by sex hormones

OBJECTIVE

Leptin and growth hormone-binding protein (GHBP) both show gender differences that might be explained by sex hormones. To study the potential relevance of oestradiol and testosterone, we have examined 80-year-old subjects in whom oestradiol is higher in men than in women. The interrelationships between leptin, insulin, GHBP and fat mass in this age group were also investigated.

DESIGN AND SUBJECTS

Ninety-four subjects (55 females and 39 males), all 80 years old, were investigated in a community-based study. None of the investigated subjects was being treated for diabetes mellitus and none of the women had oestrogen replacement.

METHODS

Levels of testosterone, oestradiol, SHBG, IGF-I, GHBP, glucose, insulin and leptin were analysed. Body composition was measured with bioimpedance analysis (BIA).

RESULTS

As in younger age groups, serum leptin, the ratio leptin/kilogram fat mass and serum GHBP were higher in the women (all, P< or =0.007), although serum oestradiol was higher in the men (P<0.001). There were no significant associations between sex hormones and leptin or GHBP either in women or in men (all, r<0.13, P>0.1). Leptin correlated to kilogram fat mass in both women (r=0.55, P<0.001) and men (r=0.47, P=0.003), but in contrast, there were no significant correlations between GHBP and fat mass and GHBP and IGF-I, either in women or in men (all, r<0.24, P>0.2). Insulin and leptin were significantly associated with GHBP, both in women (r=0.48, P<0.001 and r=0.43, P=0.001, respectively) and in men (r=0.40, P=0.01 and r=0.34, P=0.03, respectively).

CONCLUSIONS

Although the 80-year-old men had higher oestradiol levels than the women, the women had higher levels of leptin and GHBP. There were no correlations between sex hormones and leptin and GHBP, which indicates that the gender differences are not caused by sex hormones in old age. In contrast to studies in younger subjects, GHBP did not correlate to fat mass in the investigated 80-year-old men and women. In the older subjects investigated, as in younger subjects, GHBP was significantly correlated with leptin and insulin.

Bioethical theory and practice in genetic screening for type 1 diabetes

Due to the potential ethical and psychological implications of screening, and especially in regard of screening on children without available and acceptable therapeutic measures, there is a common view that such procedures are not advisable. As part of an independent research- and bioethical case study, our aim was therefore to explore and describe bioethical issues among a representative sample of participant families (n = 17,055 children) in the ABIS (All Babies In South-east Sweden) research screening for Type 1 diabetes (IDDM). The primary aim is the identification of risk factors important for the development of diabetes and other multifactorial immune-mediated diseases. Four hundred, randomly chosen, participant mothers were asked to complete a questionnaire exploring issues of information, informed consent, bio-material, confidentiality and autonomy, and of prevention/intervention. 293 completed the questionnaire, resulting in a response rate of 73.3%. The majority of questions had the form of 6-point Likert-type response scales (1-6). We found that the majority of respondents felt calm in in regard of samples and written material, and also concerning the possibility of their child in the future being identified as having high risk of developing Type 1 diabetes. An important finding concerning access and control of mainly biological data was indicated, with the respondents expressing concern for potential future use. We believe our findings indicate that this kind of empirical studies can substantially contribute to our understanding of bioethical issues of medical research involving genetics. Issues, such as safeguards ensuring the ethical criteria of autonomy and respect, were emphasised by our respondents. We believe the issues brought up may promote further discussion, and do suggest issues for consideration by, among others, researchers, bioethicists and Institutional Review Boards.

Attitudes to bioethical issues: a case study of a screening project

Commonly expressed in theoretical discussions about ethical problems in the context of epidemiology and screening is the need for more data. A study was carried out involving 21 explorative interviews with participant and nonparticipant mothers in a neonatal research screening project in progress in Sweden, ABIS (All Babies in Southeast Sweden). The respondents were asked, by way of open-ended questions, to give their opinions about certain ethical issues: informed consent; reasons for joining/declining; surrogate decision; the collection, analysis and storage of written and "live" material (biobanks); intervention etc. The ethical implications mentioned in the literature mostly concern the risk of creating distress and anxiety (anxiety and possible stigmatisation in respect of positive or false-positive results, worry about material collected and stored, distress caused by blood sampling procedures, etc.). Our results do not support the idea that the risks are substantial. The respondents rather indicate an attitude of benevolence--they are positive both to the current research on children, to the material they contribute (both written material and "biomaterial"), to possible results and intervention plans. On the other hand the participants expressed concern about the storage of material and the right to be informed of any screening/project results. Further studies in this field are needed and would be of help in theoretical discussion, the work of ethical committees and the designing of, for example, screening and research projects.

Sequencing of the Francisella tularensis strain Schu 4 genome reveals the shikimate and purine metabolic pathways, targets for the construction of a rationally attenuated auxotrophic vaccine

Francisella tularensis is the etiological agent of tularemia, a serious disease in several Northern hemisphere countries. The organism has fastidious growth requirements and is very poorly understood at the genetic and molecular levels. Given the lack of data on this organism, we undertook the sample sequencing of its genome. A random library of DNA fragments from a highly virulent strain (Schu 4) of F. tularensis was constructed and the nucleotide sequences of 13,904 cloned fragments were determined and assembled into 353 contigs. A total of 1.83 Mb of nucleotide sequence was obtained that had a G+C content of 33.2%. Genes located on plasmids pOM1 and pNFL10, which had been previously isolated from low virulence strains of F. tularensis, were absent but all of the other known F. tularensis genes were represented in the assembled data. F. tularensis Schu4 was able to grow in the absence of aromatic amino acids and orthologues of genes which could encode enzymes in the shikimate pathway in other bacteria were identified in the assembled data. Genes that could encode all of the enzymes in the purine biosynthetic and most of the en- zymes in the purine salvage pathways were also identified. This data will be used to develop defined rationally attenuated mutants of F. tularensis, which could be used as replacements for the existing genetically undefined live vaccine strain.

Three-pion interferometry results from central Pb+Pb collisions at 158A GeV/c

Three-particle correlations have been measured for identified pi(-) from central 158A GeV Pb+Pb collisions by the WA98 experiment at CERN. A substantial contribution of the genuine three-body correlation has been found as expected for a mainly chaotic and symmetric source.

Concentrations of plasma methylmalonic acid in 80-year-olds show only weak relation to psychological performance

Most studies of the relation between psychological performance in the elderly and deficiencies of cobalamin and folate have used methods that determine the blood concentrations of these vitamins, which might not reflect the vitamin status in the tissues. Recently, two new markers, plasma homocysteine and methylmalonic acid, have attracted growing interest since they are considered to reflect the status of cobalamins and folates in the tissues. In a previous study, we noted a strong association between five parameters of well-being and lower concentrations of plasma homocysteine. In the present study, we have extended these observations by determination of plasma methylmalonic acid in the same healthy elderly population. In the present study, 18 out of 100 subjects had increased plasma methylmalonic acid and in 7 of these subjects, the concentrations of serum cobalamin, blood folate, plasma homocysteine and serum creatinine were within normal limits. The relation between plasma methylmalonic acid concentrations and concentrations of serum cobalamin and blood folates and five parameters of well-being were investigated. Concentrations of plasma methylmalonic acid were only weakly associated with the concentrations of serum cobalamin and lower scores on the logical reasoning test. The present study clearly shows that the levels of plasma methylmalonic acid show a much lesser association with the parameters of well-being than did plasma homocysteine.

Social relationships and health as predictors of life satisfaction in advanced old age: results from a Swedish longitudinal study

This longitudinal study examines the relationship between family and friend social support, health, and life satisfaction for a single cohort of eighty-year-old persons living in Lund, Sweden. Results indicate that participants who remained in the study are healthier and score higher on life satisfaction when compared with those who either drop-out or die prior to age eighty-three. Even though well-integrated with family and friends, the number of friends decreases significantly from eighty to eighty-three years; those who reported no close friends nearly doubled from eighty to eighty-three years. However, for those with close friends, contact with friends increases with age. In contrast to previous research, a correlational analysis indicates that neither child nor friend support is related to life satisfaction at either eighty or eighty-three years. However, health measures and satisfaction with sibling contact are related to total life satisfaction at age eighty-three only. These findings indicate the multidimensionality of both social support and life satisfaction for the old-old.

Insomnia in an 80-year-old population: relationship to medical, psychological and social factors

In this study, insomnia in 80-year-olds was related to medical, psychological and social factors. The data were based on examinations every year in people aged between 80 and 89 years. Of 333 people living in the city of Lund and born in 1908, 67% participated. Increased severity of insomnia was significantly associated with use of diuretics, other cardiovascular drugs, hypnotics and laxatives, and with nervousness, difficulty relaxing, anorexia, nausea, constipation, backache, feeling cold, sweating, loss of weight, dizziness, depression, general fatigue, exhaustion, angina pectoris, cardiac insufficiency, worsened objective and subjective health, presence of negative T-waves on ECG, anxiety, total life satisfaction, neuroticism, disbelief in a just world, feeling lonely and lower survival rates. Thus insomnia has widespread associations with different aspects of life in 80-year-olds.

Coexpression of mRNA for the full-length neurotrophin receptor trk-C and trk-A in favourable neuroblastoma

Neuroblastoma, a childhood tumour of the sympathetic nervous system, may sometimes regress spontaneously in infants, or progress to a poor clinical outcome despite intensive therapy. Neuroblastomas express neurotrophin receptors and high levels of mRNA for trk-A correlates with favourable outcome, whereas trk-B mRNA is expressed by more unfavourable tumours. Using a sensitive RNase protection assay, mRNA expression for the neurotrophin receptor trk-C was investigated in 50 tumour samples from 45 children at different stages including metastatic and relapsing tumour tissue, out of which 22 were also investigated for trk-A mRNA. Thirty-seven of 43 primary tumours (86%) showed trk-C mRNA with more than 300-fold difference between the highest and the lowest values. A higher trk-C index (trk-C mRNA/GAPDH mRNA) was associated with favourable features such as younger age (P = 0.009-0.003), favourable tumour stage (1, 2 or 4S; P < 0.001) and favourable prognosis (P = 0.044). Better survival probability was shown in children with intermediate or high trk-C index compared with patients with low or undetectable levels (P = 0.031). All localised tumours co-expressed mRNA for trk-A and trk-C receptors. RT-PCR analysis detected mRNA encoding the cytoplasmic trk-C tyrosine kinase region only in favourable neuroblastomas. We conclude that favourable neuroblastoma may express the full-length trk-C receptor while unfavourable tumours, especially those with MYCN amplification, seem to either express no trk-C or truncated trk-C receptors with unknown biological function. Trk-C and possibly its preferred ligand NT-3 may be involved in the biology of favourable neuroblastomas showing apoptosis or differentiation.

Doctors' attitudes towards empirical data--a comparative study

In the assessment of the effects of medical technologies, the focus is most often on the quality of the empirical data. In order to shed light on the question whether medical researchers are really so empirically oriented we conducted the following study. 600 questionnaires were sent by mail to three groups, selected at random: 1) pre-clinical researchers; 2) clinical researchers who received research grants from The Swedish Medical Research Council; and 3) general practitioners. The questionnaire was built around three cases concerning the assessment of the effects of: a) H-2-receptor antagonists, b) coronary by-pass surgery and c) the homeopathic treatment of hay fever. The results indicate that there are rather small differences in how the three groups assessed the three technologies and larger differences within one and the same group concerning different cases. The tendency is that the more one considers that empirical data should be assessed independent of theoretical considerations, the higher are the demands which are placed on the quality and quantity of the empirical documentation, and vice-versa.

Blood pressure in relation to medical, psychological and social variables in a population of 80-year-olds. Survival during 6 years

OBJECTIVES

To relate elevated blood pressure in 80-year-olds to symptoms, life satisfaction and survival.

DESIGN

Examinations of medical, psychological and social factors every year between 80 and 86 years of age.

SETTING

Primary health care in the city of Lund in southern Sweden.

SUBJECTS

Three-hundred and thirty-three persons living in the city of Lund and born in 1908. Participation rate was 67%.

INTERVENTION

Abnormal findings were further examined and treated.

MAIN OUTCOME MEASURES

Symptoms, blood pressure, laboratory values, psychological factors, cognition, living conditions, and survival.

RESULTS

Hypertension according to the definition used was found in 70%. Women were over-represented (P < 0.05). Amongst persons with alleged hypertension, diuretics (P < 0.001) and 'other cardiovascular drugs' (P < 0.001) were more often used. Analgesics were more often used amongst assessed hypertensives (P < 0.05). Those with assessed hypertension scored better in testing of cognition compared to nonhypertensives (P < 0.05), and less often lived in institutions (P < 0.001). Assessed hypertensives had a better survival than alleged hypertensives during the following 7 years (P < 0.01).

CONCLUSIONS

Eighty-year-olds with assessed hypertension in the consulting room showed fewer symptoms and had a better cognition and survival than alleged hypertensives (those with a history of hypertension).