57 POTENTIALLY INAPPROPRIATE MEDICATION USE AND MORTALITY IN PATIENTS WITH COGNITIVE IMPAIRMENT

Background

Potentially inappropriate medications (PIMs are associated with falls, hospitalisation, and cognitive decline. Few studies have investigated the association between PIMs related to cognitive impairment (PIMCog) and mortality in dementia or mild cognitive impairment (MCI).

Methods

This was a retrospective observational study. Patients diagnosed with MCI or dementia (DSM-IV criteria) presenting to a tertiary-referral memory clinic from 2013–2019 were eligible. The primary outcome was all-cause death. Secondary outcomes were vascular death and non-vascular death defined according to formal certification. The primary exposure variable of interest was PIMCog, defined as any medication in the Beers 2015 or STOPP criteria, classified as potentially inappropriate for patients with cognitive impairment. Anticholinergic burden was measured using the anticholinergic cognitive burden (ACB) scale. Polypharmacy was defined as ≥5 medications. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

Results

There were 418 patients included (n = 261 dementia, n = 157 MCI). The median age was 79 (interquartile range {IQR} 74–82) and median follow-up was 809 days (IQR 552–1,571). One or more PIMCog was prescribed in 141 patients (33.4%). PIMCog use was associated with all-cause mortality after adjustment for age, sex, dementia severity, Charlson Co-morbidity Index, chronic obstructive pulmonary disease, congestive cardiac failure, and peripheral vascular disease (HR 1.96, 95% CI 1.24–3.09). PIMCog use was associated with vascular death (HR 3.28, 95% CI 1.51–7.11) but not with non-vascular death (HR 1.40 95% CI: 0.78–2.52). Neither an ACB ≥3 (HR 0.87, 95% CI: 0.46–1.64) or polypharmacy (HR 1.87, 95% CI: 0.67–5.24) were associated with death.

Conclusion

The burden of PIMCog use in patients with cognitive impairment is high. PIMCog use is independently associated with all-cause mortality and vascular death. This is a potential modifiable risk factor for death in patients with neurocognitive disorders. Further research is required to independently validate this finding.

509 POTENTIALLY INAPPROPRIATE MEDICATION USE AND MORTALITY IN PATIENTS WITH COGNITIVE IMPAIRMENT

Introduction

Potentially inappropriate medications (PIMsare associated with falls, hospitalisation, and cognitive decline. Few studies have investigated the association between PIMsrelated to cognitive impairment (PIMCog) and mortality in dementia or mild cognitive impairment (MCI).

Methods

This was a retrospective observational study. Patients diagnosed with MCI or dementia (DSM-IV criteria) presenting to a tertiary-referral memory clinic from 2013–2019 were eligible. The primary outcome was all-cause death. Secondary outcomes were vascular death and non-vascular death defined according to formal certification. The primary exposure variable of interest was PIMCog, defined as any medication in the Beers 2015 or STOPP criteria, classified as potentially inappropriate for patients with cognitive impairment. Anticholinergic burden was measured using the anticholinergic cognitive burden (ACB) scale. Polypharmacy was defined as ≥5 medications. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

Results

There were 418 patients included (n = 261 dementia, n = 157 MCI). The median age was 79 (interquartile range {IQR} 74–82) and median follow-up was 809 days (IQR 552–1,571). One or more PIMCog was prescribed in 141 patients (33.4%). PIMCog use was associated with all-cause mortality after adjustment for age, sex, dementia severity, Charlson Co-morbidity Index, chronic obstructive pulmonary disease, congestive cardiac failure, and peripheral vascular disease. (HR 1.96, 95% CI 1.24–3.09). PIMCog use was associated with vascular death (HR 3.28, 95% CI 1.51–7.11) but not with non-vascular death (HR 1.40 95% CI: 0.78–2.52). Neither an ACB ≥3 (HR 0.87, 95% CI: 0.46–1.64) or polypharmacy (HR 1.87, 95% CI: 0.67–5.24) were associated with death.

Conclusion

The burden of PIMCog use in patients with cognitive impairment is high. PIMCog use is independently associated with all-cause mortality and vascular death. This is a potential modifiable risk factor for death in patients with neurocognitive disorders. Further research is required to independently validate this finding.

Pelagic food webs of humic lakes show low short-term response to forest harvesting

Forest harvest in the boreal zone can increase the input of terrestrial materials such as dissolved organic carbon (DOC) and nitrate (NO₃^- ) into nearby aquatic ecosystems, with potential effects on phytoplankton growth through enhanced nutrient (i.e., positive) or reduced light availability (i.e., negative), which may affect ecosystem productivity and consumer resource use. Here, we conducted forest clear-cutting experiments in the catchments of four small, humic, and nitrogen-limited unproductive boreal lakes (two controls and two clear-cut, 18% and 44% of area cut) with one reference and two impact years. Our aim was to assess the effects of forest clear-cutting on pelagic biomass production and consumer resource use. We found that pelagic biomass production did not change after two years of forest clear-cutting: Pelagic primary and bacterial production (PP, BP), PP:BP ratio, chl a, and seston carbon (seston C) were unaffected by clear-cutting; neither did tree harvest affect seston stoichiometry (i.e., N:phosphorus [P], C:P) nor induce changes in zooplankton resource use, biomass, or community composition. In conclusion, our findings suggest that pelagic food webs of humic lakes (DOC > 15 mg/L) might be resilient to a moderate form of forest clear-cutting, at least two years after tree removal, before mechanical site preparation (e.g., mounding, plowing) and when leaving buffer strips along lakes and incoming streams. Thus, pelagic food web responses to forest clear-cutting might not be universal, but could depend on factors such as the time scale, share of catchment logged, and the forest practices involved, including the application of buffer strips and site preparation.

Risk assessment of high concentrations of molybdenum in forage

Molybdenum is toxic to ruminants when present in high levels in forage, causing physiological copper deficiency. A critical level for ruminants is 3-10 mg Mo kg^-1 dry matter. The average Mo level varies considerably between different arable soils, depending mainly on soil parent material. This study investigated the possibility of using various existing sources of geospatial information (geophysical, biogeochemical and soil chemical) to develop a geography-based risk assessment system. Forage samples (n = 173) were collected in 2006-2007. Three types of national geoscientific datasets were tested: (1) SEPA topsoil, comprising data from arable land within the Swedish environmental monitoring programme; (2) SGU biogeochemical, containing data from aquatic plant root material collected in small streams; and (3) SGU geophysical, consisting of data from airborne gamma-ray scanning. The digital postcode area map was used for geocoding, with Mo concentrations in forage assigned to arable parts of the corresponding postcode area. By combining this with the three national geoscientific databases, it was possible to construct a risk map using fuzzy classification depicting High-risk, Intermediate-risk, Low-risk and Very-low-risk areas. The map was validated using 42 randomly selected samples. All samples but one with Mo > 3 mg kg^-1 were found in postcode areas designated High risk. Thus, the risk map developed seems to be useful as a decision support system on where standard forage analyses need to be supplemented with Mo analyses.

Burns in Sweden: temporal trends from 1987 to 2010

Our aim was to investigate the epidemiology of burned patients admitted to hospitals in Sweden, and to examine temporal trends during the last three decades. Our hypothesis was that there has been an appreciable decline in the number of patients admitted. Retrospective data about burned patients treated at Swedish hospitals 1987 - 2010 were obtained from the Swedish National Board of Health and Welfare. Patients with primary or secondary ICD diagnoses of burns were included, reviewed and statistically interpreted in terms of sex, age, incidence, mortality in hospital and duration of stay. A total of 30,478 patients were admitted to hospitals with burns. The absolute number of admissions declined by 42% (95% CI 39 to 44). There was a highly significant reduction of 45% (95% CI: 38 to 51) in the ageadjusted incidence (admissions/million population) over the years, and the reduction was significant for both sexes. Children aged 0-4 years (n=8308) were most likely to be admitted to hospital (27%). The median duration of stay shortened over time (p < 0.0001). There was an overall significant reduction in deaths at hospital/100 admissions over time (p <0.0001). We think that the improvements are the result of a combination of preventive measures, improved treatments and greater use of outpatient facilities. If we understand these trends and the relations between age-adjusted incidence and actual number of admissions, we can gain insight into what is needed for future provision of emergency health care.

High-throughput screening reveals enzyme and GPCR targets as putative binding sites for D-deprenyl

Aims

In PET studies of patients suffering from chronic pain following whip lash trauma, d-deprenyl was shown to bind to painful sites in the neck [1]. High uptake points towards an existence of an inflammation-specific binding site. Thus, the aim of this study was to identify the binding site for d-deprenyl employing radioligand receptor binding and high-throughput analysis of its activity towards 165 G-protein coupled receptors and 84 enzyme targets commonly used in drug discovery and development.

Methods

D-Deprenyl activity towards GPCR targets was assessed by DiscoverX in CHO-K1 EDG1 β-arrest in EFC cell line utilizing the PathHunter™ technique. Enzyme inhibition by D-deprenyl was identified in the EnzymeProfiling™ screening panel provided by Eurofins Cerep Panlabs. [H3]D-deprenyl binding studies with specific GPCR agonists and enzyme inhibitors at newly identified targets were also performed.

Results

Our investigation revealed that a 10μM concentration of d-deprenyl inhibited MAO-B and MAO-A activity by 99% and 55%, respectively. In addition, a 70% inhibition of angiotens in converting enzyme (ACE) activity in rabbit lung preparations was found. Furthermore, binding studies in rat mitochondrial membrane homogenates confirmed a submicromolar [H3]D-deprenyl competition with a selective MAO-B inhibitor seligiline, but not with the selective MAO-A inhibitor pirlindole mesylate. No evident hits among GPCR targets were identified. However, attention was drawn towards the histamine HRH1 and HRH3 receptors to which d-deprenyl showed a 20% and 42% antagonistic activity.

Conclusions

MAO-B might be a candidate target for D-deprenyl, as many other studies documented higher d-deprenyl uptake in activated astrocytes, non-secreting pituitary adenomas and brown adipose tissue, where MAO-B is over expressed. Moreover, ACE inhibition was shown to hamper down-regulation of transcription factors preventing ROS-mediated cartilage damage.

Cerebrospinal fluid levels of substance P (SP) N-terminal fragment SP1–7 in patients with neuropathic pain

Aims

Neuropathic pain is a complex and painful condition, which is difficult to treat and causes a lot of suffering. The substance P (SP) system is well known to be involved in nociceptive signaling and it has previously been shown that the cerebrospinal fluid (CSF) level of SP is decreased in neuropathic pain. In this study we analyzed CSF from chronic neuropathic pain patients for the levels of SP1–7, an N-terminal fragment of SP with the ability to alleviate thermal as well as mechanical hypersensitivity in different animal models of chronic neuropathic pain, e.g. [1,2].

Methods

CSF was collected from 11 neuropathic pain patients, treated with SCS, who had refrained from using their spinal cord stimulator for 48h. Control CSF was collected from 11 patients without any known neurological disorder, who underwent minor surgery under spinal anesthesia. The CSF samples were analyzed for the levels of SP1–7 using radioimmunoassay.

Results

The results revealed a decrease in the level of SP1–7 compared to controls. We believe that the lower level ofSP1–7 most likely is a consequence of reduced amount of its precursor SP in the neuropathic pain patients.

Conclusions

Our results indicate that the SP system is changed in patients with neuropathic pain and that SP-related peptides, including SP1–7, might serve as biological markers for the patho-physiology of chronic neuropathic pain.

Small constrained SP1-7 analogs bind to a unique site and promote anti-allodynic effects following systemic injection in mice

Previous results have shown that the substance P (SP) N-terminal fragment SP1-7 may attenuate hyperalgesia and produce anti-allodynia in animals using various experimental models for neuropathic pain. The heptapeptide was found to induce its effects through binding to and activating specific sites apart from any known neurokinin or opioid receptor. Furthermore, we have applied a medicinal chemistry program to develop lead compounds mimicking the effect of SP1-7. The present study was designed to evaluate the pharmacological effect of these compounds using the mouse spared nerve injury (SNI) model of chronic neuropathic pain. Also, as no comprehensive screen with the aim to identify the SP1-7 target has yet been performed we screened our lead compound H-Phe-Phe-NH2 toward a panel of drug targets. The extensive target screen, including 111 targets, did not reveal any hit for the binding site among a number of known receptors or enzymes involved in pain modulation. Our animal studies confirmed that SP1-7, but also synthetic analogs thereof, possesses anti-allodynic effects in the mouse SNI model of neuropathic pain. One of the lead compounds, a constrained H-Phe-Phe-NH2 analog, was shown to exhibit a significant anti-allodynic effect.

Automaton Plans

Macros have long been used in planning to represent subsequences of operators. Macros can be used in place of individual operators during search, sometimes reducing the effort required to find a plan to the goal. Another use of macros is to compactly represent long plans. In this paper we introduce a novel solution concept called automaton plans in which plans are represented using hierarchies of automata. Automaton plans can be viewed as an extension of macros that enables parameterization and branching. We provide several examples that illustrate how automaton plans can be useful, both as a compact representation of exponentially long plans and as an alternative to sequential solutions in benchmark domains such as Logistics and Grid. We also compare automaton plans to other compact plan representations from the literature, and find that automaton plans are strictly more expressive than macros, but strictly less expressive than HTNs and certain representations allowing efficient sequential access to the operators of the plan.

Analytical investigation of the properties of the neutron noise induced by vibrating absorber and fuel rods

Analytical solution methods for the neutron noise in a one-dimensional multi-region system in two-group theory, which have so far been based on the adjoint function technique, are extended here to using the forward Green's function technique. The forward Green's functions were calculated analytically for a noise source in a core surrounded by reflector regions at both sides. It is shown that with symbolic computation methods, the forward Green's function can be used for the calculation of the space- and frequency-dependent noise in the first order approximation for arbitrary noise sources which have an analytical representation. The properties of the induced neutron noise were investigated for vibrations of both absorbers and fuel assemblies, with two representations of the noise sources: a point-like source which corresponds to the vibrations of a fuel rod, and a finite width source which corresponds to vibrations of a fuel assembly. The contributions of the components induced by the fluctuations of the various types of macroscopic cross sections in the total noise are also discussed and the information content of the noise in the fast group is explored for the identification of fuel assembly vibrations.

Soluble IP4 limits NK cell effector functions by controlling PI3K signaling (P1198)

NK cells have important functions in cancer immunosurveillance, bone marrow allograft rejection, fighting infections and reproduction. NK cell-based therapies are promising blood cancer treatments. Overcoming their currently limited efficacy requires a better understanding of the molecular mechanisms controlling NK cell development and dampening their effector functions. NK cells recognize pathogen-infected or tumor cells through invariant NK cell receptors (NKR), and then kill such stressed cells. Two second-messenger pathways downstream of NKRs are required for NK cell maturation and effector responses: PIP3-generation by PI3K, and generation of DAG and IP3 by PLCγ. IP3 plays a key signaling role by mobilizing Calcium, but can also be converted into soluble inositol(1,3,4,5)tetrakisphosphate (IP4). We and others previously showed that IP4 can act as a soluble analog of the PI3K lipid-product phosphatidylinositol(3,4,5) trisphosphate (PIP3) and control PIP3-mediated signaling protein membrane recruitment and activation in thymocytes and granulocytes. Here, we show data which suggest a novel IP4 function in promoting NK cell terminal differentiation and acquisition of a mature NKR repertoire. However, in mature NK cells, IP4 limits NKR induced IFNγ secretion, granule exocytosis and target-cell clearance, in part by inhibiting the PIP3 effector-kinase Akt. This identifies IP4 as an important novel regulator of NK cell development and function, and expands our understanding of the therapeutically important mechanisms dampening NK cell responses. Our results further suggest that PI3K regulation by soluble IP4 is a broadly important signaling paradigm.

Effect of a common variant of the PCSK2 gene on reduced insulin secretion

AIM/HYPOTHESIS

Individuals at risk of developing type 2 diabetes show a progressive decline in insulin secretion and increased insulin resistance over time. However, inability of the beta cells to compensate for the increased insulin resistance represents a key defect leading to overt type 2 diabetes. The aims of the present study were to replicate the association between genetic variants of the PCSK2 gene and insulin secretion, and to explore the effect on risk of type 2 diabetes.

METHODS

Replication of PCSK2 variants against insulin secretion included 7,682 non-diabetic Scandinavian individuals. Insulin secretion was measured as the corrected insulin response or disposition index, i.e. insulin secretion adjusted for the degree of insulin resistance. Risk of type 2 diabetes was studied in 28,287 Scandinavian individuals.

RESULTS

The C-allele of PCSK2 rs2208203 was associated with reduced insulin secretion measured as the corrected insulin response (n = 8,151; β = -0.112, p = 1.3 × 10(-6)) as well as disposition index (n = 8,078, β = -0.128, p = 1.6 × 10(-7)). The variant was also associated with lower fasting glucagon levels (β = -0.084, p = 0.005) in non-diabetic individuals with a fasting plasma glucose of over 5.5 mmol/l. In human pancreatic islets, PCSK2 expression correlated negatively with HbA(1c) (n = 133, r = -0.196, p = 0.038), and showed a tendency to be lower in hyperglycaemic (HbA(1c) ≥6.0% or type 2 diabetes; n = 47, p = 0.13) than normoglycaemic (HbA(1c) >6.0%; n = 66) donors. The presence of the PCSK2 rs2208203 risk allele did not influence gene expression, nor did it show an apparent risk in terms of type 2 diabetes.

CONCLUSIONS/INTERPRETATION

A variant of the PCSK2 gene was associated with reduced glucose-stimulated insulin secretion, but also with lower glucagon levels, which could potentially counteract the effects of decreased insulin secretion on the risk of type 2 diabetes.

The Role of Macros in Tractable Planning

This paper presents several new tractability results for planning based on macros. We describe an algorithm that optimally solves planning problems in a class that we call inverted tree reducible, and is provably tractable for several subclasses of this class. By using macros to store partial plans that recur frequently in the solution, the algorithm is polynomial in time and space even for exponentially long plans. We generalize the inverted tree reducible class in several ways and describe modifications of the algorithm to deal with these new classes. Theoretical results are validated in experiments.

Assessing the effect of interaction between an FTO variant (rs9939609) and physical activity on obesity in 15,925 Swedish and 2,511 Finnish adults

AIMS/HYPOTHESIS

Recent reports have suggested that genotypes at the FTO locus interact with physical activity to modify levels of obesity-related traits. We tested this hypothesis in two non-diabetic population-based cohorts, the first from southern Sweden and the second from the Botnia region of western Finland.

METHODS

In total 2,511 Finnish and 15,925 Swedish non-diabetic middle-aged adults were genotyped for the FTO rs9939609 variant. Physical activity was assessed by questionnaires and standard clinical procedures were conducted, including measures of height and weight and glucose regulation. Tests of gene x physical activity interaction were performed using linear interaction effects to determine whether the effect of this variant on BMI is modified by physical activity.

RESULTS

The minor A allele at rs9939609 was associated with higher BMI in both cohorts, with the per allele difference in BMI being about 0.13 and 0.43 kg/m(2) in the Swedish and Finnish cohorts, respectively (p < 0.0001). The test of interaction between physical activity and the rs9939609 variant on BMI was not statistically significant after controlling for age and sex in either cohort (Sweden: p = 0.71, Finland: p = 0.18).

CONCLUSIONS/INTERPRETATION

The present report does not support the notion that physical activity modifies the effects of the FTO rs9939609 variant on obesity risk in the non-diabetic Swedish or Finnish adults studied here.

Methodology investigation of expirograms for enabling contact free breath alcohol analysis

The present techniques for breath alcohol determination have usability limitations concerning practical use and the time and effort required for the test person. The rationale of the physiological assumptions in a recently demonstrated technique for breath analysis without a mouthpiece is investigated in this paper. Expirograms quantifying ethanol, carbon dioxide (CO(2)) and water (H(2)O) from 30 test subjects were analysed, with respect to the influence of individual variations in end-expiratory CO(2) and H(2)O concentrations, and possible benefits from simultaneous measurement of CO(2) or H(2)O. Both healthy subjects and patients suffering from pulmonary diseases performed breath tests with small and maximum volume expiration. The breath tests were recorded basically with a standard evidential instrument using infrared absorption spectroscopy, and equipped with a mouthpiece. Average concentrations were significantly higher for the maximum than for the small expirations. For the maximum expirations, the healthy subjects had a significantly higher end-expired PCO(2) of 4.4 ± 0.5 kPa (mean ± standard deviation) than the patients (3.9 ± 0.7 kPa). The corresponding values for H(2)O were 39 ± 1 and 38 ± 1 mg l(-1). The results indicate that the CO(2) variability is consistent with the requirements of accuracy for alcohol ignition interlocks. In addition, CO(2) as tracer gas is preferable to H(2)O due to its low concentration in ambient air. In instruments for evidential purposes H(2)O may be required as tracer gas for increased accuracy. Furthermore, the study provides support for early determination of breath alcohol concentration, indicating that determination after 2 s will introduce an additional random error of 0.02 mg l(-1) or less.

Unique splicing pattern of the TCF7L2 gene in human pancreatic islets

AIMS/HYPOTHESIS

Intronic variation in the TCF7L2 gene exhibits the strongest association to type 2 diabetes observed to date, but the mechanism whereby this genetic variation translates into altered biological function is largely unknown. A possible explanation is a genotype-dependent difference in the complex splicing pattern; however, this has not previously been characterised in pancreatic or insulin target tissues. Here, the detailed TCF7L2 splicing pattern in five human tissues is described and dependence on risk genotype explored.

METHODS

RT-PCR and quantitative real-time PCR were employed to characterise TCF7L2 splicing in pancreatic islets, blood lymphocytes, skeletal muscle and subcutaneous and visceral adipose tissue from non-diabetic individuals.

RESULTS

The mapping of TCF7L2 splice variants shows a specific pattern in pancreatic islets, with four predominant transcripts and high usage of the variable exons 4 and 15. The overall concentration of TCF7L2 mRNA is highest in islets and fat and lower in blood and muscle. No significant difference in overall amount or splicing pattern was observed between carriers and non-carriers of the rs7903146 risk (T) allele. However, incorporation of exon 4 in islets correlates positively with plasma HbA(1c) levels (r = 0.758; p = 0.018).

CONCLUSIONS/INTERPRETATION

There were pronounced tissue-specific differences in the splicing of TCF7L2 with forms containing exon 4 and 15 being most abundant in islets. The incorporation of exon 4 in islets correlated with HbA(1c) levels. Further experiments will be needed to determine the direction of this correlation, and larger cohorts needed to unequivocally resolve whether there is a relationship between genotype and splicing in islets.

Interaction between prenatal growth and high-risk genotypes in the development of type 2 diabetes

AIMS/HYPOTHESIS

Early environmental factors and genetic variants have been reported to be involved in the pathogenesis of type 2 diabetes. The aim of this study was to investigate whether there is an interaction between birthweight and common variants in the TCF7L2, HHEX, PPARG, KCNJ11, SLC30A8, IGF2BP2, CDKAL1, CDKN2A/2B and JAZF1 genes in the risk of developing type 2 diabetes.

METHODS

A total of 2,003 participants from the Helsinki Birth Cohort Study, 311 of whom were diagnosed with type 2 diabetes by an OGTT, were genotyped for the specified variants. Indices for insulin sensitivity and secretion were calculated.

RESULTS

Low birthweight was associated with type 2 diabetes (p = 0.008) and impaired insulin secretion (p = 0.04). Of the tested variants, the risk variant in HHEX showed a trend towards a low birthweight (p = 0.09) and the risk variant in the CDKN2A/2B locus was associated with high birthweight (p = 0.01). The TCF7L2 risk allele was associated with increased risk of type 2 diabetes. Pooling across all nine genes, each risk allele increased the risk of type 2 diabetes by 14%. [corrected] Risk variants in the HHEX, CDKN2A/2B and JAZF1 genes interacted with birthweight, so that the risk of type 2 diabetes was highest in those with lower birthweight (p <or= 0.05). The interaction was also present in the pooled data.

CONCLUSIONS/INTERPRETATION

Low birthweight might affect the strength of the association of some common variants (HHEX, CDKN2A/2B and JAZF1) with type 2 diabetes. These findings need to be replicated in independent cohorts.

Planning over Chain Causal Graphs for Variables with Domains of Size 5 Is NP-Hard

Recently, considerable focus has been given to the problem of determining the boundary between tractable and intractable planning problems. In this paper, we study the complexity of planning in the class C_n of planning problems, characterized by unary operators and directed path causal graphs. Although this is one of the simplest forms of causal graphs a planning problem can have, we show that planning is intractable for C_n (unless P = NP), even if the domains of state variables have bounded size. In particular, we show that plan existence for C_n^k is NP-hard for k>=5 by reduction from CNFSAT. Here, k denotes the upper bound on the size of the state variable domains. Our result reduces the complexity gap for the class C_n^k to cases k=3 and k=4 only, since C_n^2 is known to be tractable.

Hemodynamic and hormonal changes induced by noise

Eighteen healthy male volunteers with normal hearing were exposed to industrial noise at different sound levels (75, 85 and 95 dB A) in a noise laboratory. Blood pressure, heart rate, stroke volume and cardiac output were recorded with noninvasive techniques. Adrenaline and noradrenaline concentration in venous plasma were analyzed before and during noise exposure. The mean resting blood pressure of the whole group was 120/70 mm Hg. During noise stimulation diastolic blood pressure increased (12.2%, p less than 0.001) as did mean arterial pressure (6.6%, p less than 0.001) and total peripheral resistance (12.7%, p less than 0.001). Stroke volume (7.3%, p less than 0.001) and cardiac output (5.0%, p less than 0.01) were both reduced at 95 dB A. Heart rate and systolic blood pressure did not change significantly. At 75 and 85 dB A there were similar but smaller changes in the hemodynamic parameters. There were no changes in adrenaline and noradrenaline in plasma during maximal noise exposure. The noise induced hemodynamic changes remained 5 minutes after the noise stimulation was stopped but had disappeared after 10 minutes of rest.

Noise as a contributory factor in the development of elevated arterial pressure. A study of the mechanisms by which noise may raise blood pressure in man

Arterial pressure and other hemodynamic variables (stroke volume (SV), cardiac output and total peripheral resistance) were studied in 18 healthy males before and during exposure to recorded industrial noise. All measurements took place under strictly standardized conditions in a noise laboratory. the frequency distribution and level of noise used for stimulation were continuously monitored and kept constant within close limits throughout the experiments. SV was measured with impedance cardiography. Indirect blood pressure (BP) in the brachial artery was measured with an automatic device and the derived parameters, cardiac output and total peripheral resistance, were calculated from these measurements. Compared with resting conditions at 40 dBA, stimulation with industrial noise at 95 dBA caused significant increases in diastolic BP, mean arterial pressure and total peripheral resistance. Minor but statistically significant reductions of SV and cardiac output were seen. Heart rate and systolic BP did not change. These alterations of the hemodynamic variables persisted throughout 20 min of noise stimulation and were maintained for 5 min following cessation of noise stimulation. All variables had returned to their initial levels 10 min after discontinuation of noise stimulation. This study suggests that exposure to industrial noise at levels prevailing during several industrial processes may cause acute elevations of arterial BP and peripheral vascular resistance. In animal studies, repeated elevations of BP due to exposure to noise have been shown to cause a permanent elevation of BP. Therefore, we suggest that noise may be one of several external stimuli contributing to the development of arterial hypertension in man.

The search for putative unifying genetic factors for components of the metabolic syndrome

AIMS/HYPOTHESIS

The metabolic syndrome is a cluster of factors contributing to increased risk of cardiovascular disease and type 2 diabetes but unifying mechanisms have not been identified. Our aim was to study whether common variations in 17 genes previously associated with type 2 diabetes or components of the metabolic syndrome and variants in nine genes with inconsistent association with at least two components of the metabolic syndrome would also predict future development of components of the metabolic syndrome, individually or in combination.

METHODS

Genetic variants were studied in a large prospective study of 16,143 non-diabetic individuals (mean follow-up time 23 years) from the Malmö Preventive Project. In this study, development of at least three of obesity (BMI >or= 30 kg/m(2)), dyslipidaemia (triacylglycerol >or= 1.7 mmol/l and/or lipid-lowering treatment), hypertension (blood pressure >or= 140/90 mmHg and/or antihypertensive medication) and hyperglycaemia (fasting plasma glucose >or= 5.6 mmol/l and/or known diabetes) was defined as development of the metabolic syndrome. The risk of developing at least three components of the metabolic syndrome or the individual components was calculated by logistic regression adjusted for age at baseline, follow-up time and sex.

RESULTS

Polymorphisms in TCF7L2 (rs7903146, OR 1.10, 95% CI 1.04-1.17, p = 0.00097), FTO (rs9939609, OR 1.08, 95% CI 1.02-1.14, p = 0.0065), WFS1 (rs10010131, OR 1.07, 95% CI 1.02-1.13, p = 0.0078) and IGF2BP2 (rs4402960, OR 1.07, 95% CI 1.01-1.13, p = 0.021) predicted the development of at least three components of the metabolic syndrome in both univariate and multivariate analysis; in the case of TCF7L2, WFS1 and IGF2BP this was due to their association with hyperglycaemia (p < 0.00001, p = 0.0033 and p = 0.027, respectively) and for FTO it was due to its association with obesity (p = 0.004). A polymorphism in the GCKR gene predicted dyslipidaemia (rs1260326, OR 1.15, 95% CI 1.09-1.22, p < 0.00001) but not the metabolic syndrome. None of the studied polymorphisms was associated with more than two components of the metabolic syndrome. A composite genotype score of the 17 polymorphisms associated with type 2 diabetes predicted the development of at least three components of the metabolic syndrome (OR 1.04, p < 0.00001) and the development of hyperglycaemia (OR 1.06, p < 0.00001). Carriers of >or=19 risk alleles had 51 and 72% increased risk of developing at least three components of the metabolic syndrome and hyperglycaemia, respectively, compared with carriers of <or=12 risk alleles (p < 0.00001 for both).

CONCLUSIONS/INTERPRETATION

Polymorphisms in susceptibility genes for type 2 diabetes (TCF7L2, WFS1, IGF2BP2) and obesity (FTO) predispose to the metabolic syndrome by increasing the risk of one specific component of the metabolic syndrome. The findings argue against a unifying genetic component for the metabolic syndrome.

The Complexity of Planning Problems With Simple Causal Graphs

We present three new complexity results for classes of planning problems with simple causal graphs. First, we describe a polynomial-time algorithm that uses macros to generate plans for the class 3S of planning problems with binary state variables and acyclic causal graphs. This implies that plan generation may be tractable even when a planning problem has an exponentially long minimal solution. We also prove that the problem of plan existence for planning problems with multi-valued variables and chain causal graphs is NP-hard. Finally, we show that plan existence for planning problems with binary state variables and polytree causal graphs is NP-complete.

Using catchment models to establish measure plans according to the Water Framework Directive

A participatory modelling process (DEMO) has been developed and applied in a 350 km2 catchment in southern Sweden. The overall goal is to improve the dialogues between experts and local stakeholders by using numerical models as a platform for discussions. The study is focused on reducing nutrient load and on the development of a locally established measure plan, which is requested by the European Water Framework Directive. The HBV-NP model was chosen as it can calculate effects and costs for different allocations of several combined measures in a catchment. This paper shows the impact of including local data in the modelling process vs. using more general data. It was found that modelled diffuse nutrient pollution was highly modified when including local know-how, soft information and more detailed field investigations. Leaching from arable land was found to be 35% higher using more detailed information on for instance, agricultural practices, crop and soil distribution. Moreover, the stakeholders' acceptance of model results and reliance on experts was increased by applying the participatory process and involving stakeholders in the modelling procedure.

How participatory can participatory modeling be? Degrees of influence of stakeholder and expert perspectives in six dimensions of participatory modeling

The authors are involved in a project aiming at the development of a methodology for participatory modeling as a tool for public participation in water resource management. In this paper, some examples of different degrees of stakeholder influence in six key dimensions of participatory modeling are identified and discussed. Arnstein's (A ladder of citizen participation. Journal of the American Institute of Planners, 1969, 4, 216-224) critical discussion of different degrees of "real" decision-making power is taken as a point of departure to assess possible degrees of stakeholder influence. Can we as participatory modelers be sure that we are really inviting our research objects to an equal communicative relationship where local perspectives, knowledge and priorities are respected to the same extent as central and/or expert perspectives? This paper presents an approach that could be used as a tool for structured reflection to avoid unreflective tendencies towards expert knowledge dominance and low degree of stakeholders' real influence over the process.

Evaluation of antidecubitus mattresses

Pressure sores are a current problem in hospitals and care of the elderly, leading to protracted hospital stays and a high care burden. The trauma for the patients is severe, and the cost of pressure sore prevention and treatment, is considerable. Antidecubitus mattresses are used for prevention and in treatment, but they also contribute to the cost of treating pressure sores. The problem highlighted in the review is that the mattresses' effectiveness in preventing and treating pressure sores has not been sufficiently evaluated. When antidecubitus mattresses are evaluated, it is often only with regard to aspects of the interface pressure and the mattresses' ability to redistribute the pressure. The review points out the important observation that, to be able to evaluate the efficacy of the antidecubitus mattress, the mattress's effect on tissue viability needs to be studied. The parameters that ought to be considered when evaluating a support surface are: interface pressure, pressure and blood flow distribution, temperature and humidity in the skin-support surface interface. The authors propose that the effect on tissue viability of external loading can be assessed by simultaneous measurement of the interface pressure and tissue perfusion.

Proinsulin C-peptide and its C-terminal pentapeptide: degradation in human serum and Schiff base formation with subsequent CO2 incorporation

Processing of human proinsulin C-peptide and its C-terminal pentapeptide in blood serum was studied using reverse-phase HPLC and electrospray mass spectrometry. The results reveal degradation of both peptides, with a longer half-life for intact C-peptide than for the C-terminal pentapeptide. Products from C-peptide degradation were not distinguishable from the peptide background, suggesting endopeptidase degradation of C-peptide. In contrast, a set of products from the C-terminal pentapeptide were identifiable and corresponded to successive losses from the N terminus, showing that the pentapeptide is degraded by aminopeptidase in serum. Consistent with this finding, a slower degradation was found for the N-acetyl-protected pentapeptide. Removal of serum proteins by acetone precipitation produced N-terminally carbamate-modified C-peptide via a Schiff base intermediate (a ketimine with acetone), to which CO(2) was added and acetone removed, generating a cyclic side chain via anhydride formation. The modification was not seen with the pyroglutamate form of C-peptide, with the N-terminally acetylated C-peptide, or with a control peptide having N-terminal Phe, but was found with human C-peptide, its N-terminal tetrapeptide, and a rat C-peptide fragment (all with N-terminal Glu). Hence, the modification appears to require N-terminal Glu, but this is not the only prerequisite since the C-terminal pentapeptide and another control peptide (also starting with Glu) were not modified. A peptide aldimine Schiff base leading to CO(2) incorporation was detected with formaldehyde in NaHCO(3). The observation that C-peptide forms Schiff bases with ketones/aldehydes, enhancing covalent attachment of CO(2), may have biological implications.

Post-traumatic stress among Swedish ambulance personnel

OBJECTIVE

Emergency workers, including ambulance personnel, must cope with a variety of duty related stressors including traumatic incident exposures. Little is known about the variables that might be associated with post-traumatic stress symptom in high risk occupational groups such as ambulance personnel. This study investigated the prevalence of post-traumatic stress disorder among Swedish ambulance personnel.

METHODS

To estimate the prevalence of trauma related disorders, a representative group of 362 ambulance personal from the county of Västra Götaland in Sweden was surveyed through use of a Swedish version of Antonovsky's 13-item short version of Sense of Coherence Scale, to measure reactions to traumatic events two instruments were used, Impact of Event Scale (IES-15) and the Post Traumatic Symptom Scale (PTSS-10). A total of 223 of the ambulance personnel reported that they had had experience of what they described as traumatic situations.

RESULTS

Of those who reported a traumatic situation 15.2% scored 31 or more on the IES-15 sub scale. Scores over 31 indicate a stress reaction with certain likelihood of post-traumatic disorder. On the PTSS-10 subscale 12.1% scored 5 or more, which indicates a relative strong reaction. The study indicates that lower sense of coherence predicts post-traumatic stress. Other predictors for the extent of traumatic stress were longer job experience, age, physical and psychological workload.

CONCLUSIONS

The high prevalence of post-traumatic stress disorder symptoms in ambulance personnel indicates an inability to cope with stress in daily work. The strong relation between post-traumatic stress and Sense of Coherence Scale may be useful in predicting vulnerability for post-traumatic symptoms among recently employed ambulance service personnel. To prevent or reduce the upcoming of post-traumatic stress disorder symptoms it must be possible to take leave of absence, or for a longer or shorter time be transferred to non-emergency duties. This study presents a better understanding between post-traumatic stress and underlying factors among ambulance personnel.

Bacterioplankton Production in Lakes along an Altitude Gradient in the Subarctic North of Sweden

We examined changes in bacterioplankton standing stock and production in subarctic lakes in the north of Sweden to elucidate their coupling to lake physical, chemical, and biological characteristics. Sixteen lakes situated along an altitude gradient extending from the coniferous forest to the high-alpine belt were studied during 1998 and 1999. The summer mean bacterial numbers and production varied substantially between the lakes, with a general trend toward decreasing values with increasing altitude. The results demonstrate that P probably restricted bacterial utilization of DOC in the coniferous forest lakes, while low DOC concentrations limited bacterial growth during the summer in the alpine lakes. The primary production of plankton was insufficient to support bacterial production in the lakes. High input of allochthonous DOC to the alpine lakes in spring was sufficient both to increase the bacterial production and to induce P-limitation. As a consequence, there was a tendency toward higher bacterial activity in the spring compared to the summer in the alpine lakes. The results indicate that most of the bacterial standing stock and production are supported by allochthonous DOC plus DOC from benthic production, and more or less limited by the phosphorus supply. We therefore suggest that bacteria populations in subarctic lakes may be indirectly affected by climate variations through its impact on the input of DOC and nutrients from the lake catchments.

N-terminal acetylation in a third protein family of vertebrate alcohol dehydrogenase/retinal reductase found through a 'proteomics' approach in enzyme characterization

A recent finding of a novel class of retinol-active alcohol dehydrogenase (ADH) in frog prompted analysis of this activity in other vertebrate forms. Surprisingly, yet another and still more unrelated ADH was identified in chicken tissues. It was found to be a member of the aldo-keto reductase (AKR) enzyme family, not previously known as an ADH in vertebrates. Its terminal blocking group and the N-terminal segment, not assigned by protein and cDNA structure analysis, were determined by electrospray tandem mass spectrometry after protein isolation by two-dimensional gel electrophoresis. The N terminus is Acetyl-Ala- and the N-terminal segment contains two consecutive Asn residues. The results establish the new ADH enzyme of the AKR family and show the usefulness of combined gel separation and mass spectrometry in enzyme-characterization.