Longitudinal associations between depression and diabetes complications: a systematic review and meta-analysis.

To conduct a systematic review and meta-analysis of longitudinal studies assessing the bi-directional association between depression and diabetes macrovascular and microvascular complications. Embase, Medline and PsycINFO databases were searched from inception through 27 November 2017. A total of 4592 abstracts were screened for eligibility. Meta-analyses used multilevel random/mixed-effects models. Quality was assessed using the Newcastle-Ottawa scale. Twenty-two studies were included in the systematic review. Sixteen studies examined the relationship between baseline depression and incident diabetes complications, of which nine studies involving over one million participants were suitable for meta-analysis. Depression was associated with an increased risk of incident macrovascular (HR = 1.38; 95% CI: 1.30-1.47) and microvascular disease (HR = 1.33; 95% CI: 1.25-1.41). Six studies examined the association between baseline diabetes complications and subsequent depression, of which two studies involving over 230 000 participants were suitable for meta-analysis. The results showed that diabetes complications increased the risk of incident depressive disorder (HR = 1.14; 95% CI: 1.07-1.21). The quality analysis showed increased risk of bias notably in the representativeness of selected cohorts and ascertainment of exposure and outcome. Depression in people with diabetes is associated with an increased risk of incident macrovascular and microvascular complications. The relationship between depression and diabetes complications appears bi-directional. However, the risk of developing diabetes complications in depressed people is higher than the risk of developing depression in people with diabetes complications. The underlying mechanisms warrant further research.

Burnout, psychosomatic symptoms and job satisfaction among Dutch nurse anaesthetists: a survey.

BACKGROUND: To meet the increasing demand for healthcare providers, it is crucial to recruit and retain more nurse anaesthetists (NAs). The majority of NAs in the Netherlands are >45 years old, and retaining them in their jobs is very important. This study investigates the relationships among burnout, physical health and job satisfaction among Dutch NAs. METHODS: Two thousand NAs working in Dutch hospitals were invited to participate in this online questionnaire. We tested the relationships among burnout, psychosomatic symptoms, sickness absence, perceived general health and job satisfaction. RESULTS: Nine hundred and twenty-three questionnaires were completed and analysed (46% response rate). Burnout and psychosomatic symptoms were negatively associated with job satisfaction, and predicted 27% of job satisfaction. Perceived general health was positively and sickness absence was negatively related to job satisfaction. Older NAs had a higher incidence of burnout than their younger counterparts. CONCLUSIONS: The results confirmed the importance of a healthy psychosocial work environment for promoting job satisfaction. To prevent burnout, further research is necessary to determine the factors causing stress. These findings may also apply to anaesthesiologists who share many tasks and work in close cooperation with NAs.

Personality dimensions and their relationship with job satisfaction amongst Dutch nurse anaesthetists.

AIM: This study investigates the relationship between personality dimensions and job satisfaction. BACKGROUND: The shortage of nurses, and those voluntarily leaving their jobs, continues to be a problem affecting the delivery of healthcare all over the world, including anaesthesia. If it is found that nurse anaesthetists with certain personality types have high levels of job satisfaction, the information may be helpful for the retention of nurse anaesthetists. METHODS: A questionnaire was distributed amongst Dutch nurse anaesthetists. Factor and multiple regression analyses were performed to reveal personality dimensions and their impact on job satisfaction. RESULTS: Nine hundred and twenty-three questionnaires were completed and analysed (46% response rate). Two personality dimensions -'easy going' and 'orderly'- explained 3.5% of the variance in job satisfaction. CONCLUSION: Personality dimensions as measured with the Myers-Briggs Type Indicator (MBTI) are only minimally relevant in predicting job satisfaction amongst Dutch nurse anaesthetists. IMPLICATIONS FOR NURSING MANAGEMENT: Before using personality traits as a selection tool for retaining employees, it is important to understand the relationship of particular personalities to job satisfaction; it is also important to know which combination of personality traits is likely to create a highly cohesive work group.

Job satisfaction amongst Dutch nurse anaesthetists: the influence of emotions on events.

BACKGROUND: An ageing population, combined with a shortage of health-care professionals, can result in a decrease in the capacity of health-care systems. Therefore, it is important to explore possible solutions for this problem. By finding methods to increase job satisfaction, it may be possible to retain employees within their profession. In this study, we examined events, their influence on emotions and, consequently, the effect of these emotions on job satisfaction. We attempted to answer the question: Which events and emotions influence job satisfaction? METHODS: We collected data on events and emotions, and their effects on job satisfaction, amongst Dutch nurse anaesthetists. Participants (n = 314) were asked to complete two questionnaires about events, emotions and job satisfaction at two different times during an average working day. RESULTS: One hundred thirty-two nurse anaesthetists from 24 Dutch hospitals participated. Both positive and negative events were significant in the development of positive and negative emotions at the end of the working day. Positive emotions at the end of the working day contributed significantly to job satisfaction. Negative emotions did not have a significant effect on job satisfaction. CONCLUSIONS: The mediating role of positive emotions in relation to positive and negative events should be taken into account in managing job satisfaction amongst Dutch nurse anaesthetists. Further research is necessary to determine whether the relationship between events and emotions provides a foundation for developing a more positive working atmosphere, and also to explore how hospitals can trigger positive emotions to increase job satisfaction.

Factors associated with the onset of major depressive disorder in adults with type 2 diabetes living in 12 different countries: results from the INTERPRET-DD prospective study.

AIMS: To examine the factors that are associated with changes in depression in people with type 2 diabetes living in 12 different countries. METHODS: People with type 2 diabetes treated in out-patient settings aged 18-65 years underwent a psychiatric assessment to diagnose major depressive disorder (MDD) at baseline and follow-up. At both time points, participants completed the Patient Health Questionnaire (PHQ-9), the WHO five-item Well-being scale (WHO-5) and the Problem Areas in Diabetes (PAID) scale which measures diabetes-related distress. A composite stress score (CSS) (the occurrence of stressful life events and their reported degree of 'upset') between baseline and follow-up was calculated. Demographic data and medical record information were collected. Separate regression analyses were conducted with MDD and PHQ-9 scores as the dependent variables. RESULTS: In total, there were 7.4% (120) incident cases of MDD with 81.5% (1317) continuing to remain free of a diagnosis of MDD. Univariate analyses demonstrated that those with MDD were more likely to be female, less likely to be physically active, more likely to have diabetes complications at baseline and have higher CSS. Mean scores for the WHO-5, PAID and PHQ-9 were poorer in those with incident MDD compared with those who had never had a diagnosis of MDD. Regression analyses demonstrated that higher PHQ-9, lower WHO-5 scores and greater CSS were significant predictors of incident MDD. Significant predictors of PHQ-9 were baseline PHQ-9 score, WHO-5, PAID and CSS. CONCLUSION: This study demonstrates the importance of psychosocial factors in addition to physiological variables in the development of depressive symptoms and incident MDD in people with type 2 diabetes. Stressful life events, depressive symptoms and diabetes-related distress all play a significant role which has implications for practice. A more holistic approach to care, which recognises the interplay of these psychosocial factors, may help to mitigate their impact on diabetes self-management as well as MDD, thus early screening and treatment for symptoms is recommended.

Overtrained horses alter their resting pulsatile growth hormone secretion.

The influence of intensified and reduced training on nocturnal growth hormone (GH) secretion and elimination dynamics was studied in young (1.5 yr) Standardbred geldings to detect potential markers indicative for early overtraining. Ten horses trained on a treadmill for 32 wk in age-, breed-, and gender-matched fixed pairs. Training was divided into four phases (4, 18, 6, and 4 wk, respectively): 1) habituation to high-speed treadmill trotting, 2) normal training, in which speed and duration of training sessions were gradually increased, 3) in this phase, the horses were divided into 2 groups: control (C) and intensified trained (IT) group. In IT, training intensity, duration, and frequency were further increased, whereas in control these remained unaltered, and 4) reduced training (RT). At the end of phases 2, 3, and 4, blood was sampled overnight every 5 min for 8 h for assessment of GH secretory dynamics using pulse detection, deconvolution analysis, and approximate entropy (ApEn). Intensified training induced overtraining (performance decreased by 19% compared with C), which was associated with an increase in concentration peaks number (3.6 vs. 2.0, respectively), a smaller peak secretion pattern with a prolonged half-life (15.2 vs. 7.3 min, respectively), and an increased ApEn (0.89 vs. 0.49, respectively). RT did not lead to full recovery for the overtrained horses. The increased irregularity of nocturnal GH pulsatility pattern is indicative of a loss of coordinated control of GH regulation. Longer phases of somatostatin withdrawal are hypothesized to be the underlying mechanism for the observed changes in GH pulsatility pattern.

The danger of metabolic pathways with turbo design.

Many catabolic pathways begin with an ATP-requiring activation step, after which further metabolism yields a surplus of ATP. Such a 'turbo' principle is useful but also contains an inherent risk. This is illustrated by a detailed kinetic analysis of a paradoxical Saccharomyces cerevisiae mutant; the mutant fails to grow on glucose because of overactive initial enzymes of glycolysis, but is defective only in an enzyme (trehalose 6-phosphate synthase) that appears to have little relevance to glycolysis. The ubiquity of pathways that possess an initial activation step, suggests that there might be many more genes that, when deleted, cause rather paradoxical regulation phenotypes (i.e. growth defects caused by enhanced utilization of growth substrate).

Discriminating work context factors in the working environment of Dutch nurse anesthetists.

With an ever increasing number of patients and more demanding health care system it is important to keep nurse anesthetists as mentally and physically fit as possible. Especially with a shortage of nurse anesthetists it is important to know which work context factors are important for maintaining a healthy balance between the nurse anesthetist and his work environment. This study is the first to determine which work context factors of nurse anesthetists are most relevant for a healthy work environment. A questionnaire survey, containing work related items, was distributed among all nurse anesthetists working in Dutch hospitals. All together 882 questionnaires (response rate 44%) were completed and analyzed, including factor analysis for the discriminating work context factors. Four discriminating work context factors (career/rewards, relation with supervisor, task contents and social environment) were found to be relevant, explaining 48% of the variance in work context. All four work context factors are considered to be job resources, although not hospital related. Supervisors (head nurses) interpret these work context factors differently from nurse anesthetists, which can result in dissatisfaction of the latter group. Nurse anesthetists participate more in sub-functions and activities in larger peripheral and academic anesthesia departments. Smaller anesthesia departments require nurse anesthetists to be more flexible and perform many different functions within the anesthesia domain.

A functional genomics strategy that uses metabolome data to reveal the phenotype of silent mutations.

A large proportion of the 6,000 genes present in the genome of Saccharomyces cerevisiae, and of those sequenced in other organisms, encode proteins of unknown function. Many of these genes are "silent, " that is, they show no overt phenotype, in terms of growth rate or other fluxes, when they are deleted from the genome. We demonstrate how the intracellular concentrations of metabolites can reveal phenotypes for proteins active in metabolic regulation. Quantification of the change of several metabolite concentrations relative to the concentration change of one selected metabolite can reveal the site of action, in the metabolic network, of a silent gene. In the same way, comprehensive analyses of metabolite concentrations in mutants, providing "metabolic snapshots," can reveal functions when snapshots from strains deleted for unstudied genes are compared to those deleted for known genes. This approach to functional analysis, using comparative metabolomics, we call FANCY-an abbreviation for functional analysis by co-responses in yeast.

Association of bacteriorhodopsin with lipid-impregnated filters. Evidence for fusion of bacteriorhodopsin-containing vesicles with the lipid phase of the filter.

Bacteriorhodopsin vesicles were associated with cellulose-nitrate filters impregnated with a solution of phospholipids in hexadecane. The generation of (photo)potentials upon illumination of the filter was studied in the absence and presence of ionophores, phospholipase A2, EDTA or polyene antibiotics. From these experiments the following conclusions are drawn. 1. Upon illumination of the filter, bacteriorhodopsin pumps protons into aqueous compartments located in the filter. 2. These aqueous compartments possibly do not originate from the compartments enclosed by the bacteriorhodopsin vesicles. Evidence is obtained that aqueous compartments are present in the surface layers of the lipid-impregnated filters. 3. The results are explained most easily by a mechanism, whereby fusion occurs between the vesicles and the lipids of the filter.

On the stoichiometry between uncouplers of oxidative phosphorylation and respiratory chains. The catalytic action of SF 6847 (3,5-di-tert-butyl-4-hydroxy-benzylidenemalononitrile).

Titration of State 4 rat-liver mitochondria at pH 7.2 with the uncoupler 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile (SF 6847) at various concentrations of mitochondria and using various substrates indicates that under optimal conditions less than 0.2 molecule of 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile per respiratory chain is sufficient to induce complete uncoupling. This result suggests that there is not a stoichiometric relationship between uncoupler molecules and cytochrome c oxidase, involved in oxidative phosphorylation, or between the former and phosphorylation assemblies. Experiments on the release by 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile of azide-inhibited respiration of State 3 mitochondria and titrations with 5-chloro-3-tert-butyl-2'-chloro-4'-nitrosalicylanilide (S13) of State 4 mitochondria at various mitochondrial concentrations confirm this conclusion.

Effect of concentration of substrates and products on the growth of Klebsiella pneumoniae in chemostat cultures.

Non-equilibrium thermodynamics (NET) can be used to describe microbial growth. In this description, the concentrations of products contribute to the driving forces of the metabolic processes (anabolism and catabolism). Thus, in contrast to the model of bacterial growth of Monod (Recherches sur la Croissance les Cultures Bactériennes (1942) Herman et Cie, Paris), it is predicted that the growth rate of a bacterial chemostat culture is, in principle, dependent on the concentration of the catabolic product (for instance HCO3-) during catabolite limitation and on the concentration of the anabolic product (for instance biomass) during anabolite limitation. In order to test this prediction, Klebsiella pneumoniae was grown in aerobic citrate-limited, glucose-limited or ammonia-limited chemostat cultures. Ammonia-limited cultures were considered to be essentially anabolite-limited, whereas citrate limitation was used as a representative for catabolite limitation. In ammonia-limited or in glucose-limited cultures it was found that the growth rate was independent of the biomass concentration present. In the NET description this means that the 'back' reaction (i.e., in the direction from biomass to substrates) is saturated with respect to biomass. On the other hand, in citrate-limited cultures, the steady-state concentration of citrate increased with the concentration of the catabolic product HCO3-. At relatively low concentrations of HCO3-, 'thermodynamic back-pressure' of growth (i.e., increase in product concentration was compensated by an increase in substrate concentration so that the driving force for growth remained almost constant) was demonstrated as predicted by the NET model. At concentrations above 40 mM, a kinetic (allosteric) effect of HCO3- was detected. This was concluded from a reduced growth yield on citrate, and from a significant decrease in the maximal growth rate and the maximal oxygen consumption rate after relief of the citrate limitation.

Uncoupler-inhibitor titrations of ATP-driven reverse electron transfer in isolated rat-liver mitochondria.

Uncoupler-inhibitor titrations of ATP-driven reverse electron transfer across the first site of the respiratory chain were performed in isolated rat-liver mitochondria, and the experimental results were compared with the predictions of a simple delocalized chemiosmotic mechanism. The rates of ATP hydrolysis (Jp) and reverse electron transfer (-J0) were measured at different uncoupler (S-13) concentrations, either in the absence or in the presence of rotenone. When the rates -J0 and Jp measured at different uncoupler concentrations were expressed as percentages of the activity at zero uncoupler concentration, it was found that the efficiency of S-13 to uncouple the reverse electron transfer and to stimulate ATP hydrolysis was not significantly changed upon partial inhibition with rotenone. These results are in contrast with data from a study of uncoupler-inhibitor titrations in submitochondrial particles published previously, in which a higher effectiveness of several uncouplers to inhibit ATP-driven reverse electron transfer was observed in the presence of rotenone.

Control of choline oxidation by rat-liver mitochondria.

The steady-state concentrations of choline and its reaction products in intact rat-liver mitochondria were determined under different conditions. From these measurements, it is concluded that in a sucrose medium choline dehydrogenation and betaine aldehyde dehydrogenation are the rate-limiting steps in overall choline oxidation under "State-3" or uncoupled conditions, respectively. Ageing of the mitochondria leads to changes in the mitochondrial membrane, resulting in a markedly different pattern of oxidation products. This finding explains why rotenone inhibits oxygen uptake with choline as substrate in fresh but not in aged mitochondria.

Thermodynamic efficiency of bacterial growth calculated from growth yield of Pseudomonas oxalaticus OX1 in the chemostat.

In order to determine the thermodynamic efficiency of bacterial growth, Pseudomonas oxalaticus OX1 was grown in carbon-limited continuous cultures. 11 different carbon sources, ranging from oxalate (most oxidised component) to ethanol (most reduced component), were used as limiting substrate in these experiments. From the experimental yield values (expressed as C-mol dry weight produced per C-mol carbon substrate consumed) the thermodynamic efficiencies were calculated. On substrates more reduced than biomass (such as ethanol and glycerol) the thermodynamic efficiency of growth of P. oxalaticus was negative but it reached a maximum of 23 +/- 3% with substrates with a degree of reduction of 3 (citrate) and lower. The actual concentrations of the components involved were incorporated into the calculations but this affected the overall thermodynamic efficiency only to a small extent. This result strengthens the conclusion of Westerhoff et al. (Westerhoff, H.V., Hellingwerf, K.J. and Van Dam, K. (1983) Proc. Natl. Acad. Sci. 80, 305-309) that bacteria have been optimised towards a theoretical thermodynamic efficiency of 24%, corresponding with maximisation of growth rate at optimal efficiency, with highly oxidised substrates.

Unique relationships between the rates of oxidation and phosphorylation and the protonmotive force in rat-liver mitochondria.

The rate of ATP synthesis (JP) in isolated rat-liver mitochondria was strongly dependent on the magnitude of the protonmotive force (delta mu H+) across the mitochondrial inner membrane. Addition of different concentrations of various uncouplers or malonate to mitochondrial incubations in State 3 led to a depression of delta mu H+ and a concomitant decrease in JP. A unique relationship between JP and delta mu H+ was obtained, which was independent of the way in which delta mu H+ was varied. This unique relationship was observed when K+ (in the presence of valinomycin) was used as a probe for delta psi. Different relationships between JP and delta mu H+ were observed when K+ was used as a probe for delta psi and when K+ was measured after separation of the mitochondria by centrifugation without silicone oil. This led to a serious underestimation of delta psi, specifically when uncouplers were present, and non-unique flow-force relationships were thus obtained. Anomalous relationships between JP and delta mu H+ were also found when TPMP+ was used as a probe for delta psi. However, in uncoupler incubations the presence of TBP- strongly affected the TPMP+ accumulation ratio without any effect on the K+ accumulation or on JP and in the presence of TBP- unique relationships between JP and delta mu H+ were again obtained. This indicates that the accumulation of TPMP+ inside the mitochondria is not a straightforward function of delta psi but also depends on conditions like the presence of TBP- or uncouplers. We conclude that there is a unique relationship between the rate of phosphorylation and the protonmotive force in mitochondria and that under some conditions the behaviour of TPMP+ is anomalous.

ATP-driven transhydrogenase provides an example of delocalized chemiosmotic coupling in reconstituted vesicles and in submitochondrial particles.

The mechanism of coupling between mitochondrial ATPase (EC 3.6.1.3) and nicotinamide nucleotide transhydrogenase (EC 1.6.1.1) was studied in reconstituted liposomes containing both purified enzymes and compared with their behavior in submitochondrial particles. In order to investigate the mode of coupling between the transhydrogenase and the ATPase by the double-inhibitor and inhibitor-uncoupler methods, suitable inhibitors of transhydrogenase and ATPase were selected. Phenylarsine oxide and A3'-O-(3-(N-(4-azido-2-nitrophenyl)amino)propionyl)-NAD+ were used as transhydrogenase inhibitors, whereas of the various ATPase inhibitors tested aurovertin was found to be the most convenient. The inhibition of the ATP-driven transhydrogenase activity was proportional to the inhibition of both the ATPase and the transhydrogenase. Inhibitor-uncoupler titrations showed an increased sensitivity of the coupled reaction towards carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP)--an uncoupler that preferentially uncouples localized interactions, according to Herweijer et al. (Biochim. Biophys. Acta 849 (1986) 276-287)--when the primary pump was partially inhibited. However, when the secondary pump was partially inhibited the sensitivity towards FCCP remained unchanged. Similar results were obtained with submitochondrial particles. These results are in contrast to those obtained previously with the ATP-driven reverse electron flow. In addition, the amount of uncoupler required for uncoupling of the ATP-driven transhydrogenase was found to be similar to that required for the stimulation of the ATPase activity, both in reconstituted vesicles and in submitochondrial particles. Uncoupling of reversed electron flow to NAD+ required much less uncoupler. On the basis of these results, it is proposed that, in agreement with the chemiosmotic model, the interaction between ATPase and transhydrogenase in reconstituted vesicles as well as in submitochondrial particles occurs through the delta mu H+. In contrast, the energy transfer between ATPase and NADH-ubiquinone oxidoreductase appears to occur via a more direct interaction, according to the above-mentioned results by Herweijer et al.

Amino acid transport in plasma membrane vesicles from isolated rat liver parenchymal cells.

Plasma membrane vesicles were prepared from isolated rat liver parenchymal cells. The transport of several amino acids was studied and found to be identical to that in membrane vesicles from whole liver tissue.

Linear relation between rate and thermodynamic force in enzyme-catalyzed reactions.

Starting from enzyme kinetics, it is shown that generally a linear rather than a proportional relationship exists between rate and free energy changes in biochemical processes. In the derivation the boundary condition of constant substrate plus product is used, which is appropriate for many cellular systems. An example is the ADP plus ATP concentration is mitochondrial oxidative phosphorylation, as is illustrated experimentally.

Specific labelling of the (Ca2+ + Mg2+)-ATPase of Escherichia coli with 8-azido-ATP and 4-chloro-7-nitrobenzofurazan.

1. 8-Azido-ATP is a substrate for Escherichia coli (Ca2+ + Mg2+)-ATPase (E. coli F1). 2. Illumination of E. coli F1 in the presence of 8-azido-ATP causes inhibition of ATPase activity. The presence of ATP during illumination prevents inhibition. 3. 8-Azido-ATP and 4-chloro-7-nitrobenzofurazan (NbfCl) bind predominantly to the alpha subunit of the enzyme, but also significantly to the beta subunit. 4. The alpha subunit of E. coli F1 seems to have some properties that in other F1-ATPases are associated with the beta subunit.