Risk factors for suicide in bipolar disorder: a cohort study of 12 850 patients.

OBJECTIVE: Bipolar disorder carries a high risk of suicide. Identification of risk factors is important. The aim of this study was to study risk factors for suicide in a large cohort of men and women with bipolar disorder. METHOD: A prospective cohort study using clinical data from the Swedish National Quality Register for Bipolar Affective Disorder (BipoläR). The outcome variable was suicide captured in the Cause of Death Register between 2004 and 2014. Hazard ratios (HR) were calculated using Cox proportional hazards models. RESULTS: Of 12 850 persons (4844 men and 8006 women) with bipolar disorder, 90 (55 men and 35 women) died by suicide during the follow-up period (between 1 and 10 years). Male sex (HR 2.56), living alone (HR 2.45), previous suicide attempts (HR 4.10), comorbid psychiatric disorder (HR 2.64), recent affective episodes (HR 2.39), criminal conviction (HR 4.43), psychiatric inpatient care (HR 2.79), and involuntary commitment (HR 3.50) were significant risk factors for suicide. Several of the statistically significant risk factors for suicide in bipolar disorder differed between men and women. CONCLUSIONS: Risk factors for suicide in bipolar disorder include factors associated with suicide in general, but also diagnosis-specific factors.

Weight gain with add-on second-generation antipsychotics in bipolar disorder: a naturalistic study.

OBJECTIVE: Our aim was to investigate the prevalence and magnitude of weight gain in-patients with bipolar disorder when treated with a second-generation antipsychotic as an add-on treatment to a mood stabilizer in routine clinical practice. METHODS: Data were derived from the quality register for bipolar disorder in Sweden (BipoläR). Patients with bipolar disorder who started add-on treatment with a SGA (n = 575) were compared at next yearly follow-up with age and sex matched patients who were only treated with a mood stabilizer (n = 566). The primary outcome measure was change in body weight and body mass index (BMI). We also assessed the prevalence of clinically significant weight gain defined as ≥7% gain in body weight. RESULTS: The group that received add-on treatment with antipsychotics neither gained more weight nor were at higher risk for a clinically significant weight gain than the reference group. Instead, factors associated with clinically significant weight gain were female sex, young age, low-baseline BMI, and occurrence of manic/hypomanic episodes. CONCLUSION: We found no evidence of an overall increased risk of weight gain for patients with bipolar disorder after receiving add-on SGA to a mood stabilizer in a routine clinical setting.

An enzyme in the kynurenine pathway that governs vulnerability to suicidal behavior by regulating excitotoxicity and neuroinflammation.

Emerging evidence suggests that inflammation has a key role in depression and suicidal behavior. The kynurenine pathway is involved in neuroinflammation and regulates glutamate neurotransmission. In the cerebrospinal fluid (CSF) of suicidal patients, levels of inflammatory cytokines and the kynurenine metabolite quinolinic acid (QUIN), an N-methyl-d-aspartate receptor agonist, are increased. The enzyme amino-ß-carboxymuconate-semialdehyde-decarboxylase (ACMSD) limits QUIN formation by competitive production of the neuroprotective metabolite picolinic acid (PIC). Therefore, decreased ACMSD activity can lead to excess QUIN. We tested the hypothesis that deficient ACMSD activity underlies suicidal behavior. We measured PIC and QUIN in CSF and plasma samples from 137 patients exhibiting suicidal behavior and 71 healthy controls. We used DSM-IV and the Montgomery-Åsberg Depression Rating Scale and Suicide Assessment Scale to assess behavioral changes. Finally, we genotyped ACMSD tag single-nucleotide polymorphisms (SNPs) in 77 of the patients and 150 population-based controls. Suicide attempters had reduced PIC and a decreased PIC/QUIN ratio in both CSF (P<0.001) and blood (P=0.001 and P<0.01, respectively). The reductions of PIC in CSF were sustained over 2 years after the suicide attempt based on repeated measures. The minor C allele of the ACMSD SNP rs2121337 was more prevalent in suicide attempters and associated with increased CSF QUIN. Taken together, our data suggest that increased QUIN levels may result from reduced activity of ACMSD in suicidal subjects. We conclude that measures of kynurenine metabolites can be explored as biomarkers of suicide risk, and that ACMSD is a potential therapeutic target in suicidal behavior.

Cerebrospinal fluid metabolomics identifies a key role of isocitrate dehydrogenase in bipolar disorder: evidence in support of mitochondrial dysfunction hypothesis.

Although evidence for mitochondrial dysfunction in the pathogenesis of bipolar disorder (BD) has been reported, the precise biological basis remains unknown, hampering the search for novel biomarkers. In this study, we performed metabolomics of cerebrospinal fluid (CSF) from male BD patients (n=54) and age-matched male healthy controls (n=40). Subsequently, post-mortem brain analyses, genetic analyses, metabolomics of CSF samples from rats treated with lithium or valproic acid were also performed. After multivariate logistic regression, isocitric acid (isocitrate) levels were significantly higher in the CSF from BD patients than healthy controls. Furthermore, gene expression of two subtypes (IDH3A and IDH3B) of isocitrate dehydrogenase (IDH) in the dorsolateral prefrontal cortex from BD patients was significantly lower than that of controls, although the expression of other genes including, aconitase (ACO1, ACO2), IDH1, IDH2 and IDH3G, were not altered. Moreover, protein expression of IDH3A in the cerebellum from BD patients was higher than that of controls. Genetic analyses showed that IDH genes (IDH1, IDH2, IDH3A, IDH3B) and ACO genes (ACO1, ACO2) were not associated with BD. Chronic (4 weeks) treatment with lithium or valproic acid in rats did not alter CSF levels of isocitrate, and mRNA levels of Idh3a, Idh3b, Aco1 and Aco2 genes in the rat brain. These findings suggest that abnormality in the metabolism of isocitrate by IDH3A in the mitochondria plays a key role in the pathogenesis of BD, supporting the mitochondrial dysfunction hypothesis of BD. Therefore, IDH3 in the citric acid cycle could potentially be a novel therapeutic target for BD.

Theories of chromatographic efficiency applied to expanded beds.

Various quantities such as plate height (HETP), number of plates (N), axial dispersion coefficient (Dax) and Bodenstein number (Bo) are used to describe the efficiency of, and dispersion in chromatographic columns. Different quantities highlight different aspects of the performance. Due to the expansion of expanded-bed columns, the information contained in some of these quantities is not the same for expanded beds as for packed beds. In this article the mentioned quantities are described and discussed both theoretically and related to experimental data. It is concluded that they are often used in a confusing way. Quantities modified to be more informative when comparing beds of different expansions are developed (N(EB) = N/expansion2 and HETP(EB) = HETP x bed expansion) and recommendations of which quantity to use in what situation are given.

A model for individual and collective cell movement in Dictyostelium discoideum.

The cellular slime mold Dictyostelium discoideum is a widely used model system for studying a variety of basic processes in development, including cell-cell signaling, signal transduction, pattern formation, cell motility, and the movement of tissue-like aggregates of cells. Many aspects of cell motion are poorly understood, including how individual cell behavior produces the collective motion of cells observed within the mound and slug. Herein, we describe a biologically realistic model for motile D. discoideum cells that can generate active forces, that interact via surface molecules, and that can detect and respond to chemotactic signals. We model the cells as deformable viscoelastic ellipsoids and incorporate signal transduction and cell-cell signaling by using a previously developed model. The shape constraint restricts the admissible deformations but makes the simulation of a large number of interacting cells feasible. Because the model is based on known processes, the parameters can be estimated or measured experimentally. We show that this model can reproduce the observations on the chemotactic behavior of single cells, streaming during aggregation, and the collective motion of an aggregate of cells driven by a small group of pacemakers. The model predicts that the motion of two-dimensional slugs [Bonner, J. T. (1998) Proc. Natl. Acad. Sci. USA 95, 9355-9359] results from the same behaviors that are exhibited by individual cells; it is not necessary to invoke different mechanisms or behaviors. Our computational experiments also suggest previously uncharacterized phenomena that may be experimentally observable.

Pellicular expanded bed matrix suitable for high flow rates.

A new type of expanded bed matrix with a heavy core of stainless steel covered with an agarose layer was prepared. Two bead size fractions, the smaller one (32-75 microm diameter) having a single particle core and the larger (75-180 microm diameter) with an agglomerate of stainless steel particles constituting the core, were chosen for further characterisation. The dispersion behaviour was determined both in packed bed and expanded bed modes by the retention time distribution method (RTD) and compared with the Streamline matrix (Amersham Pharmacia Biotech). The comparison turned out in favour of the new matrix. Flow rates as high as 3000 cm/h were used with the larger fraction, giving stable expanded beds with good mass transfer properties. The matrices were mechanically stable without any tendency to crack or peal, even after prolonged use.

Locus-specific multifluor FISH analysis allows physical characterization of complex chromosome abnormalities in neoplasia.

Novel techniques in molecular cytogenetics have radically improved the ability to characterize genetic changes in neoplastic cells. In parallel, a rapid development in high-throughput genomics has resulted in detailed physical maps of the human genome. Combining these two fields, we have developed a method for the simultaneous visualization of several physically defined segments along a chromosome. Seven YAC clones and one subtelomeric cosmid clone from chromosome 12 were labeled with unique combinations of four fluors and hybridized to metaphase chromosomes from neoplastic cells. In a uterine leiomyoma and a myxoid liposarcoma with translocations 12;14 and 12;16, the breakpoints in chromosome 12 could be localized to the HMGIC and CHOP regions, respectively. In the other tumors, more complex aberrations were visualized, including two inversions in 12q with a common breakpoint between MDM2 and D12S332 in a pleomorphic adenoma, amplification of MDM2 and CDK4 in ring chromosomes from a malignant fibrous histiocytoma, and amplification of KRAS2 together with other unbalanced rearrangements in two pancreatic adenocarcinomas. Combinatorially labeled single-copy probes may thus simultaneously provide physical localization of breakpoints and an overview of complex structural rearrangements. Genes Chromosomes Cancer 28:347-352, 2000.

Divergent roles for Ras and Rap in the activation of p38 mitogen-activated protein kinase by interleukin-1.

We have found that lethal toxin from Clostridium sordellii, which specifically inactivates the low molecular weight G proteins Ras, Rap, and Rac, inhibits the activation of p38 mitogen-activated protein kinase (MAPK) by interleukin-1 (IL-1) in EL4.NOB-1 cells and primary fibroblasts. The target protein involved appeared to be Ras, because transient transfections with dominant negative RasN17 inhibited p38 MAPK activation by IL-1. Furthermore, transfections of cells with constitutively active RasVHa-activated p38 MAPK. Further evidence for Ras involvement came from the observation that IL-1 caused a rapid activation of Ras in the cells and from the inhibitory effects of the Ras inhibitors manumycin A and damnacanthal. Toxin B from Clostridium difficile, which inactivates Rac, Cdc42, and Rho, was without effect. Dominant negative versions of Rac (RacN17) or Rap (Rap1AN17) did not inhibit the response. Intriguingly, transfection of cells with dominant negative Rap1AN17 activated p38 MAPK. Furthermore, constitutively active Rap1AV12 inhibited p38 MAPK activation by IL-1, consistent with Rap antagonizing Ras function. IL-1 also activated Rap in the cells, but with slower kinetics than Ras. Our studies therefore provide clear evidence using multiple approaches for Ras as a signaling component in the activation of p38 MAPK by IL-1, with Rap having an inhibitory effect.

Superporous agarose monoliths as mini-reactors in flow injection systems. On-line monitoring of metabolites and intracellular enzymes in microbial cultivation processes.

A new type of agarose material, superporous agarose, was used as a support material in an analytical system designed for monitoring of bioprocesses with respect to metabolites and intracellular enzymes. The superporous agarose was used in the form of miniaturised gel plug columns (15 x 5.0 mM I.D. monolithic gel bed). The gel plugs were designed to have one set of very large pores (about 50 microm in diameter) through which cells, cell debris and other particulate contaminants from the bioreactor could easily pass. The material also had normal diffusion pores (300 A) characteristic of all agarose materials, providing ample surface for covalent attachment of antibodies and enzymes used in the analytical sequence. The superporous agarose gel plug columns were characterised with respect to flow properties and handling of heavy cell loads as well as dispersion of injected samples (a Bodenstein number of about 40 was observed with acetone tracer at a flow rate of 1 ml min(-1)). To evaluate the practical performance of the superporous gel plug columns, two applications were studied: (1) on-line determination of glucose in cultivation broth (gel plug with immobilized glucose oxidase) and (2) immunochemical quantification of intracellular beta-galactosidase in E. coli (gel plug with lysozyme to achieve cell lysis and gel plug with antibodies against beta-galactosidase).

Faster isolation of recombinant factor VIII SQ, with a superporous agarose matrix.

A superporous agarose matrix was compared with a corresponding homogenous matrix in the isolation of recombinant factor VIII SQ (r-VIII SQ) by immunoaffinity chromatography. As a reference, the commercially available Sepharose FastFlow, used for a similar purification in the industry, was also evaluated. Breakthrough curves are described for flows between 50 and 400 cm/h with pre-purified r-VIII SQ and with cell culture broth. The superporous gel gave the best performance and a 1000-fold purification was obtained in a one-step procedure. The superporous matrix made it possible to increase the throughput about four-fold, presumably due to its better mass transfer properties. The importance of the ligand distribution profile is discussed based upon immunofluorescence microscopy data.

Selection for spiral waves in the social amoebae Dictyostelium.

Starving Dictyostelium amoebae emit pulses of the chemoattractant cAMP that are relayed from cell to cell as circular and spiral waves. We have recently modeled spiral wave formation in Dictyostelium. Our model suggests that a secreted protein inhibitor of an extracellular cAMP phosphodiesterase selects for spirals. Herein we test the essential features of this prediction by comparing wave propagation in wild type and inhibitor mutants. We find that mutants rarely form spirals. The territory size of mutant strains is approximately 50 times smaller than wild type, and the mature fruiting bodies are smaller but otherwise normal. These results identify a mechanism for selecting one wave symmetry over another in an excitable system and suggest that the phosphodiesterase inhibitor may be under selection because it helps regulate territory size.

Clonal chromosome aberrations are present in vivo in synovia and osteophytes from patients with osteoarthritis.

We have previously reported recurrent clonal chromosomal aberrations in synovia, osteophytes and articular cartilage from patients with osteoarthritis (OA). In particular, gain of chromosomes 5 and 7 was found to be strongly associated with OA. In order to exclude the possibility of in vitro artefacts, we studied three to four parallel, independent cultures from ten samples of synovia and three samples of osteophytes from ten women with primary OA. In all, 40 cultures were cytogenetically analysed, 39 of which had clonal chromosomal aberrations. The most common aberrations were +7 and +5 which were found in 38 and 12 cultures, respectively. There were striking karyotype similarities among the parallel cultures from each case. Out of a total of 83 clones, only 11 were unique for one culture, 7 from synovia and 4 from osteophytes. The genetic homogeneity among different cultures from the same patients excludes the possibility of in vitro artefacts and indicates a widespread distribution of the cytogenetically aberrant clones in vivo.

Evidence of somatic mutations in osteoarthritis.

We examined, cytogenetically and by in situ hybridization (ISH) techniques, the synovia, osteophytes, and articular cartilage from 32 patients with pronounced osteoarthritis (OA), a prevalent form of arthropathy characterized by progressive reduction of articular cartilage, and synovial samples from 17 control patients. In short-term cultures, clonal chromosome aberrations, in particular the gain of chromosomes 7 (+7) and 5 (+5), were found to be strongly associated with OA. These aberrations were found in almost 90% of the cultures from synovia and osteophytes, whereas only 1/11 synovial samples from joints unequivocally unaffected by OA had cells with +5 or +7. The in vivo nature of trisomy 7 was demonstrated by ISH on uncultured cells, and serial passaging showed that cells with +7 had a proliferative advantage in vitro. Thus, the combined data indicate that cells with somatic mutations appear early and may be influential in the disease process leading to OA.

Origin and evolution of circular waves and spirals in Dictyostelium discoideum territories.

Randomly distributed Dictyostelium discoideum cells form cooperative territories by signaling to each other with cAMP. Cells initiate the process by sending out pulsatile signals, which propagate as waves. With time, circular and spiral patterns form. We show that by adding spatial and temporal noise to the levels of an important regulator of external cAMP levels, the cAMP phosphodiesterase inhibitor, we can explain the natural progression of the system from randomly firing cells to circular waves whose symmetries break to form double- and single- or multi-armed spirals. When phosphodiesterase inhibitor is increased with time, mimicking experimental data, the wavelength of the spirals shortens, and a proportion of them evolve into pairs of connected spirals. We compare these results to recent experiments, finding that the temporal and spatial correspondence between experiment and model is very close.

Comparison of ornidazole and tinidazole in single-dose treatment of trichomoniasis in women.

A comparison is made between oral ornidazole in a single 1-5 g dose and tinidazole given in a 2 g dose using a double-blind technique. All the 45 women with Trichomonas vaginalis infection who were treated with ornidazole were cured. In the tinidazole-treated group 41 out of 43 women had negative cultures after treatment. Tolerance was good in both groups.