13 research outputs found
Suicide risk in schizophrenia: learning from the past to change the future
Suicide is a major cause of death among patients with schizophrenia. Research indicates that at least 5–13% of schizophrenic patients die by suicide, and it is likely that the higher end of range is the most accurate estimate. There is almost total agreement that the schizophrenic patient who is more likely to commit suicide is young, male, white and never married, with good premorbid function, post-psychotic depression and a history of substance abuse and suicide attempts. Hopelessness, social isolation, hospitalization, deteriorating health after a high level of premorbid functioning, recent loss or rejection, limited external support, and family stress or instability are risk factors for suicide in patients with schizophrenia. Suicidal schizophrenics usually fear further mental deterioration, and they experience either excessive treatment dependence or loss of faith in treatment. Awareness of illness has been reported as a major issue among suicidal schizophrenic patients, yet some researchers argue that insight into the illness does not increase suicide risk. Protective factors play also an important role in assessing suicide risk and should also be carefully evaluated. The neurobiological perspective offers a new approach for understanding self-destructive behavior among patients with schizophrenia and may improve the accuracy of screening schizophrenics for suicide. Although, there is general consensus on the risk factors, accurate knowledge as well as early recognition of patients at risk is still lacking in everyday clinical practice. Better knowledge may help clinicians and caretakers to implement preventive measures. This review paper is the results of a joint effort between researchers in the field of suicide in schizophrenia. Each expert provided a brief essay on one specific aspect of the problem. This is the first attempt to present a consensus report as well as the development of a set of guidelines for reducing suicide risk among schizophenia patients
A Synthetic Polymicrobial Community Biofilm Model Demonstrates Spatial Partitioning, Tolerance to Antimicrobial Treatment, Reduced Metabolism, and Small Colony Variants Typical of Chronic Wound Biofilms
Understanding chronic wound infection is key for successful treatment and requires accurate laboratory models. We describe a modified biofilm flow device that effectively mimics the chronic wound environment, including simulated wound fluid, a collagen-based 3D biofilm matrix, and a five-species mixture of clinically relevant bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Citrobacter freundii). Mixed biofilms were cultured for between 3 and 14 days with consistent numbers of bacteria that exhibited reduced metabolic activity, which increased with a high dose of glucose. S. aureus was recovered from biofilms as a small colony variant, but as a normal colony variant if P. aeruginosa was excluded from the system. Bacteria within the biofilm did not co-aggregate but formed discrete, species-specific clusters. Biofilms demonstrated differential tolerance to the topical antimicrobials Neosporin and HOCl, consistent with protection due to the biofilm lifestyle. The characteristics exhibited within this model match those of real-world wound biofilms, reflecting the clinical scenario and yielding a powerful in vitro tool that is versatile, inexpensive, and pivotal for understanding chronic wound infection
A Mechanistic Study of Thioester Hydrolysis with Heavy Atom Kinetic Isotope Effects
The
carbonyl-C, carbonyl-O, and leaving-S kinetic isotope effects
(KIEs) were determined for the hydrolysis of formylthiocholine. Under
acidic conditions, <sup>13</sup><i>k</i><sub>obs</sub> =
1.0312, <sup>18</sup><i>k</i><sub>obs</sub> = 0.997, and <sup>34</sup><i>k</i><sub>obs</sub> = 0.995; for neutral conditions, <sup>13</sup><i>k</i><sub>obs</sub> = 1.022, <sup>18</sup><i>k</i><sub>obs</sub> = 1.010, and <sup>34</sup><i>k</i><sub>obs</sub> = 0.996; and for alkaline conditions, <sup>13</sup><i>k</i><sub>obs</sub> = 1.0263, <sup>18</sup><i>k</i><sub>obs</sub> = 0.992, and <sup>34</sup><i>k</i><sub>obs</sub> = 1.000. The observed KIEs provided helpful insights into a qualitative
description of the bond orders in the transition state structure
Phenylglycine and sulfonamide correctors of defective ΔF508 and G551D cystic fibrosis transmembrane conductance regulator chloride-channel gating
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel cause cystic fibrosis. The delta F508 mutation produces defects in channel gating and cellular processing, whereas the G551D mutation produces primarily a gating defect. To identify correctors of gating, 50,000 diverse small molecules were screened at 2.5 microM (with forskolin, 20 microM) by an iodide uptake assay in epithelial cells coexpressing delta F508-CFTR and a fluorescent halide indicator (yellow fluorescent protein-H148Q/I152L) after delta F508-CFTR rescue by 24-h culture at 27 degrees C. Secondary analysis and testing of >1000 structural analogs yielded two novel classes of correctors of defective delta F508-CFTR gating ("potentiators") with nanomolar potency that were active in human delta F508 and G551D cells. The most potent compound of the phenylglycine class, 2-[(2-1H-indol-3-yl-acetyl)-methylamino]-N-(4-isopropylphenyl)-2-phenylacetamide, reversibly activated delta F508-CFTR in the presence of forskolin with K(a) approximately 70 nM and also activated the CFTR gating mutants G551D and G1349D with K(a) values of approximately 1100 and 40 nM, respectively. The most potent sulfonamide, 6-(ethylphenylsulfamoyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid cycloheptylamide, had K(a) approximately 20 nM for activation of delta F508-CFTR. In cell-attached patch-clamp experiments, phenylglycine-01 (PG-01) and sulfonamide-01 (SF-01) increased channel open probability >5-fold by the reduction of interburst closed time. An interesting property of these compounds was their ability to act in synergy with cAMP agonists. Microsome metabolism studies and rat pharmacokinetic analysis suggested significantly more rapid metabolism of PG-01 than SF-03. Phenylglycine and sulfonamide compounds may be useful for monotherapy of cystic fibrosis caused by gating mutants and possibly for a subset of delta F508 subjects with significant delta F508-CFTR plasma-membrane expression
A Kinetic Isotope Effect and Isotope Exchange Study of the Nonenzymatic and the Equine Serum Butyrylcholinesterase-Catalyzed Thioester Hydrolysis
Formylthiocholine
(FTC) was synthesized and found to be a substrate
for nonenzymatic and butyrylcholinesterase (BChE)-catalyzed hydrolysis.
Solvent (D<sub>2</sub>O) and secondary formyl-H kinetic isotope effects
(KIEs) were measured by an NMR spectroscopic method. The solvent (D<sub>2</sub>O) KIEs are <sup>D<sub>2</sub>O</sup><i>k</i> =
0.20 in 200 mM HCl, <sup>D<sub>2</sub>O</sup><i>k</i> =
0.81 in 50 mM HCl, and <sup>D<sub>2</sub>O</sup><i>k</i> = 4.2 in pure water. The formyl-H KIEs are <sup>D</sup><i>k</i> = 0.80 in 200 mM HCl, <sup>D</sup><i>k</i> = 0.77 in 50
mM HCl, <sup>D</sup><i>k</i> = 0.75 in pure water, <sup>D</sup><i>k</i> = 0.88 in 50 mM NaOH, and <sup>D</sup>(<i>V</i>/<i>K</i>) = 0.89 in the BChE-catalyzed hydrolysis
in MES buffer at pH 6.8. Positional isotope exchange experiments showed
no detectable exchange of <sup>18</sup>O into the carbonyl oxygen
of FTC or the product, formate, under any of the above conditions.
Solvent nucleophile-O KIEs were determined to be <sup>18</sup><i>k</i> = 0.9917 under neutral conditions, <sup>18</sup><i>k</i> = 1.0290 (water nucleophile) or <sup>18</sup><i>k</i> = 0.989 (hydroxide nucleophile) under alkaline conditions, and <sup>18</sup>(<i>V</i>/<i>K</i>) = 0.9925 for BChE
catalysis. The acidic, neutral, and BChE-catalyzed reactions are explained
in terms of a stepwise mechanism with tetrahedral intermediates. Evidence
for a change to a direct displacement mechanism under alkaline conditions
is presented
Efficacy of dialectical behavior therapy in women veterans with borderline personality disorder
Support for this study was provided by a VA Research Advisory Group grant o the first author. The authors would also like to acknowledge the significant contributions of the follow-ing individuals: Theresa Yusehok and Lawrence Dural, VA staff psychiatrists providing medica-tion management, Haleh Ghanizadeh and Danuta Jagla-Sehudel, skills training roup eoleaders, and Jean Beckhana, VA staff psychologist and consultant