Molecular mechanism of serotonin transporter inhibition elucidated by a new flexible docking protocol

The two main groups of antidepressant drugs, the tricyclic antidepressants (TCAs) and the selective serotonin reuptake inhibitors (SSRIs), as well as several other compounds, act by inhibiting the serotonin transporter (SERT). However, the binding mode and molecular mechanism of inhibition in SERT are not fully understood. In this study, five classes of SERT inhibitors were docked into an outward-facing SERT homology model using a new 4D ensemble docking protocol. Unlike other docking protocols, where protein flexibility is not considered or is highly dependent on the ligand structure, flexibility was here obtained by side chain sampling of the amino acids of the binding pocket using biased probability Monte Carlo (BPMC) prior to docking. This resulted in the generation of multiple binding pocket conformations that the ligands were docked into. The docking results showed that the inhibitors were stacked between the aromatic amino acids of the extracellular gate (Y176, F335) presumably preventing its closure. The inhibitors interacted with amino acids in both the putative substrate binding site and more extracellular regions of the protein. A general structure-docking-based pharmacophore model was generated to explain binding of all studied classes of SERT inhibitors. Docking of a test set of actives and decoys furthermore showed that the outward-facing ensemble SERT homology model consistently and selectively scored the majority of active compounds above decoys, which indicates its usefulness in virtual screening.     

Sequential Flow Cytometric Analysis of Cellular DNA-Content in Peripheral Blood during Treatment for Acute Leukaemia

Sequential flow cytometric analysis (FCM) of relative nuclear DNA content per cell was done in peripheral blood of 12 patients during treatment for acute leukaemia. A marked increase of cells with S-phase DNA-content during the first hours of treatment was found in patients responding favorably to treatment. One patient with increase of ‘S-phase cells’ died before clinical improvement could be evaluated. However, lack of S-phase increase at one treatment cycle did not exclude a favorable response in the next. Two cases with probable aneuploid leukaemia showed gradual disappearance of abnormal cells during therapy. The value of FCM analysis of peripheral blood seems to be in predicting the response to treatment before clinical signs appear.     

Analysis of heparinization methods during hemodialysis

The ideal method of heparinization should achieve therapeutic concentrations (0.2-0.5 IU/mL) in the artificial kidney and the least possible amount of heparin in the patient. Total heparinization using a bolus dose (8400 IU) followed by continuous infusion of heparin (20 IU/min), initially showed 1.4-2.4 IU/mL in the artificial kidney and the patient, but unpredictable slopes. High-dose regional heparinization (120-144 IU/min) and neutralization showed sustained heparin concentrations (0.4-0.6 IU/mL) in the artificial kidney, and less than 0.2 IU/mL in the patient. Low-dose regional heparinization (25 IU/min) initially showed 0.25-0.45 IU/mL in the artificial kidney, but unpredictable slopes in the patient. Low-dose regional heparinization (25 IU/min) and neutralization showed sustained heparin concentrations (0.15-0.35 IU/mL) in the artificial kidney and less than 0.15 IU/mL in the patient.     

Synthesis, biological evaluation and molecular modeling of GW 501516 analogues

Eleven analogues of GW 501516 (1) were prepared and subjected to biological testing in a semi-high throughput human skeletal muscle cell assay. The assay testing indicated that all analogues elicited oxidation of oleic acid. Among the most potent agonists, 2e (2-{2-ethyl-4-[(4-methyl-2-(4-trifluoromethylphenyl)thiazol-5-yl)methylthio]phenoxy}-2-methylpropanoic acid), was also subjected to a luciferase-based transfection assay, which showed that this compound is a potent agonist against PPARδ and a moderate agonist against PPARα. Docking of compound 2e into PPARδ revealed that it occupied the agonist binding site and exhibited key hydrogen bonding interactions with His323, His449, and Tyr473.     

In vitro release of lysozyme from monocytes and granulocytes

When exposed to zymosan or latex particles or heat-inactivated staphylococci, freshly prepared human blood monocytes and granulocytes rapidly released a large fraction of their lysozyme content. Within 24 hours the total lysozyme activity in the monocyte suspensions tripled, while it doubled in the granulocyte suspensions, indicating synthesis of the enzyme following release. The monocytes in particular seemed to release and synthesize lysozyme without any other stimulus than contact with lymphocytes and the tube walls. Potassium caseinate in solution did not influence the lysozyme release. Myeloperoxidase and beta-glucuronidase, which in the granulocytes are kept in lysosomal fractions separate from most of the lysozyme, were neither released nor synthesized to a significant degree. Moreover, the minute amount of lactate dehydrogenase released indicated that the lysozyme release was not the result of cell lysis. Accordingly, the monocytes, which are not already stimulated by adherence to nonphagocytosable surfaces, are capable of selective enzyme release similar to that of the granulocytes.     

Chronic infectious mononucleosis; a case report

A 39-year-old woman had an adenitis colli followed by anaemia, splenomegaly, atypical lymphoid cells in blood with increased B-lymphocytes, reduced T-suppressor/cytotoxic cells, increased polyclonal IgM, high titres of EB VCA IgG, EB EA IgD&R +/- and EBNA IgG-. The disease progressed slowly for 2 years, splenectomy was followed by clinical improvement; spleen morphology was compatible with a benign disease of viral origin.     

An analysis of the one-stage prothrombin time

An analysis of the one-stage prothrombin time using thromboplastins highly (Thrombotest) and slightly (Normotest) sensitive to the Pivka (protein induced by vitamin K absence) inhibitor is presented. A one-tenth dilution of blood with 0.1 mol/l Na3 citrate was satisfactory even at an extreme packed cell volume (PCV). Whole blood and plasma were equally satisfactory as test materials; however, their accuracy and precision were greatly improved when a small sample size at a high coagulation activity and a large sample size at a low coagulation activity were used. The PCV correction method which corrected for the different Pivka inhibitor sensitivities of thromboplastins was preferable.     

Subgroups of Long-Term Sick-Listed Based on Prognostic Return to Work Factors Across Diagnoses: A Cross-Sectional Latent Class Analysis

Comorbidity is common among long-term sick-listed and many prognostic factors for return to work (RTW) are shared across diagnoses. RTW interventions have small effects, possibly due to being averaged across heterogeneous samples. Identifying subgroups based on prognostic RTW factors independent of diagnoses might help stratify interventions. The aim of this study was to identify and describe subgroups of long-term sick-listed workers, independent of diagnoses, based on prognostic factors for RTW. Latent class analysis of 532 workers sick-listed for eight weeks was used to identify subgroups based on seven prognostic RTW factors (self-reported health, anxiety and depressive symptoms, pain, self-efficacy, work ability, RTW expectations) and four covariates (age, gender, education, physical work). Four classes were identified: Class 1 (45% of participants) was characterized by favorable scores on the prognostic factors; Class 2 (22%) by high anxiety and depressive symptoms, younger age and higher education; Class 3 (16%) by overall poor scores including high pain levels; Class 4 (17%) by physical work and lack of workplace adjustments. Class 2 included more individuals with a psychological diagnosis, while diagnoses were distributed more proportionate to the sample in the other classes. The identified classes illustrate common subgroups of RTW prognosis among long-term sick-listed individuals largely independent of diagnosis. These classes could in the future assist RTW services to provide appropriate type and extent of follow-up, however more research is needed to validate the class structure and examine how these classes predict outcomes and respond to interventions.