Effect of a protracted antidepressant treatment on signal transduction and [3H](-)-baclofen binding at GABAB receptors

In membranes prepared from frontal cortex of rats receiving desmethylimipramine (10 mg/kg i.p. twice daily) or imipramine (7.5 mg/kg i.p. twice daily) for 3 weeks, the density of high-affinity gamma-aminobutyric acid (GABA)B recognition sites is increased when measured by [3H]GABA binding in the presence of an excess of bicuculline, but it is unchanged when measured by [3H](-)-baclofen binding. When the atypical antidepressant maprotiline was administered (10 mg/kg i.p. twice daily for 3 weeks), no change in the density of GABAB recognition sites was observed using either [3H]GABA or [3H](-)-baclofen as ligands. In addition, a protracted treatment with imipramine, desmethylimipramine and maprotiline failed to change GABAB receptor-coupled signal transduction as monitored by the ability of (-)-baclofen to inhibit the forskolin-stimulated adenylate cyclase activity in membranes prepared from frontal cortex and hippocampus or the cyclic AMP formation in slices from frontal cortex. Hence, after protracted antidepressant treatment, the increase of [3H]GABA binding may not reflect changes in the characteristics of the recognition sites of the GABAB receptors subclass coupled to the adenylate cyclase through a guanine nucleotide binding protein inhibitory (Ni).     

Different administration schedules of darbepoetin alfa affect oxidized and reduced glutathione levels to a similar extent in 5/6 nephrectomized rats

Background

The development of erythropoiesis-stimulating agents (ESAs) with extended serum half-lives has allowed marked prolongation of the administration intervals. The level of oxidative stress is increased in chronic kidney disease, and is reportedly decreased after long-term ESA treatment. However, the effect of different dosing regimens of ESAs on oxidative stress has not been elucidated.

Methods

Five-sixths nephrectomized (NX) rats received either 0.4 μg/kg darbepoetin alfa (DA) weekly or 0.8 μg/kg DA fortnightly between weeks 4 and 10. NX animals receiving saline and a sham-operated (SHAM) group served as controls. The levels of oxidized and reduced glutathione (GSSG, GSH) were followed from blood samples drawn fortnightly.

Results

During the follow-up, the ratios GSSG/GSH showed similar trends in both DA groups, levels being significantly lower than those in the SHAM group at weeks 8 and 10. GSSG levels were lower than the baseline throughout the study in all groups except for NX controls. The GSH levels were increased in all three NX groups (weeks 6–10) compared with both the baseline and the SHAM group

Conclusion

Our results suggest that the extent of oxidative stress is similar in response to different dosing regimens of DA in 5/6 NX rats when comparable hemoglobin levels are maintained. These findings remain to be confirmed in chronic kidney disease patients.     

Anti-inflammatory effects of a cyclosporine receptor-binding compound, D-43787

By virtue of its binding to cyclophilin, the cellular receptor for cyclosporine (CsA), we could identify a new compound D-43787 [N-[(1-tert-butyloxycarbonyl)-indolin-2-(S)-carbonyl]-indolin-2-(S)-carbonacid-[N-epsilon-benzyloxycarbonyl)-2-(S)-lysin methylester]-amide] exhibiting immunomodulating properties. It inhibited cell proliferation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA)/ionomycin and anti-CD3/CD28 with an IC(50) of 0.3 microM. The protein phosphatase calcineurin, which is the target of the CsA-cyclophilin complex, is not inhibited by D-43787. It inhibited T helper cell (Th) 2 cytokines interleukin (IL)-4, -5, and -13 more effectively than the Th1 cytokine interferon (IFN)-gamma in human primary T cells. The IC(50) for IL-5 and IL-13 in TPA/ionomycin-stimulated peripheral blood mononuclear cells (PBMC) is 0.7 +/- 0.1 and 0.5 +/- 0.1 microM, respectively, whereas the IC(50) for IFN-gamma is 2.0 +/- 0.4 microM. When PBMC were stimulated with anti-CD3/CD28, the IC(50) for IL-4, -5, and -13 were 1.5 +/- 0.2, 1.8 +/- 0.2, and 1.9 +/- 0.4 microM, respectively. IFN-gamma was only partially inhibited under these conditions. This effect was even more pronounced in pure CD4(+) T cells. Pretreatment of human monocytes with D-43787 inhibited lipopolysaccharide-induced proinflammatory cytokines IL-6 and TNFalpha with an IC(50) of 1.2 +/- 0.1 and 4.7 +/- 0.9 microM, respectively. In vivo, D-43787 potently inhibited late-phase eosinophilia in actively sensitized and challenged guinea pigs (10 mg/kg, i.p.: 51%) and Brown-Norway rats (1 mg/kg, intrapulmonary: 66% 30 mg/kg, i.p.: 50%). In adjuvant-induced arthritis, D-43787 (10-40 mg/kg, b.i.d., i.p.) dose dependently reduced edema development on both hind paws. The potency of D-43787 was comparable with that of indomethacin and dexamethasone. In conclusion, we characterized a novel Th2 selective immunosuppressive drug with possible anti-asthmatic/anti-inflammatory effects. Its mode of action is distinct from that of CsA.     

Chylothorax as a complication of coronary artery bypass grafting operation

The authors present the case of a 72-year-old woman who underwent coronary bypass grafting. Left sided chylothorax due to accidental dissection of a thoracic duct branch developed 2 months after sternotomy. As conservative therapy has failed, surgical pleurodesis was performed successfully. Chylothorax is a rare and underestimated complication of coronary bypass grafting. The worldwide increasing number of coronary artery bypass grafting surgeries makes it important to pay attention to this condition. Thus diagnosis of the chyle is relatively easy by its high chylomicron and triglyceride content, but identification of the etiology and its treatment is sometimes challenging for the physician. The treatment of chylothorax is usually conservative. The main goal is to keep the volume of the chyle under control. The number of surgical interventions because of chylothorax is increasing due to an increase of iatrogenic etiology.     

A qualitative interview study on effects of diet on children's mental state and performance. Evaluation of perceptions, attitudes and beliefs of parents in four European countries

Nutrition is one of the many factors that influence a child's cognitive development and performance. Understanding the relationship between nutrition and mental performance in children is important in terms of their attainment and productivity both in school and later life. Since parents are seen as nutritional gatekeepers for their children's diets, their views and beliefs are of crucial importance. The present study aims to qualitatively examine parents' perceptions of the relationship between diet and mental performance of children. The study was conducted with a total of 124 parents in four European countries using a semi-structured interview schedule. Parents speak of the effects of diet at two levels; the nature of the effects of diet and the characteristics of the foods responsible for these effects. Mental outcomes are related to diet, with the effects perceived to be associated with attention and concentration, often mediated by effects on children's mood and behaviour. Parents categorise foods as 'good' or 'bad' with positive effects related generally to a healthy balanced diet while negative effects are perceived to be associated with sugary and fatty foods. Understanding parental perceptions is important for many purposes including the targeting of dietary advice and prioritising of public health issues.     

Nasal and skin delivery of IC31(®)-adjuvanted recombinant HSV-2 gD protein confers protection against genital herpes

Genital herpes caused by herpes simplex virus type 2 (HSV-2) remains the leading cause of genital ulcers worldwide. Given the disappointing results of the recent genital herpes vaccine trials in humans, development of novel vaccine strategies capable of eliciting protective mucosal and systemic immune responses to HSV-2 is urgently required. Here we tested the ability of the adjuvant IC31^® in combination with HSV-2 glycoprotein D (gD) used through intranasal (i.n.), intradermal (i.d.), or subcutaneous (s.c.) immunization routes for induction of protective immunity against genital herpes infection in C57BL/6 mice. Immunization with gD plus IC31^® through all three routes of immunization developed elevated gD-specific serum antibody responses with HSV-2 neutralizing activity. Whereas the skin routes promoted the induction of a mixed IgG2c/IgG1 isotype profile, the i.n. route only elicited IgG1 antibodies. All immunization routes were able to induce gD-specific IgG antibody responses in the vaginas of mice immunized with IC31^®-adjuvanted gD. Although specific lymphoproliferative responses were observed in splenocytes from mice of most groups vaccinated with IC31^®-adjuvanted gD, only i.d. immunization resulted in a significant splenic IFN-γ response. Further, immunization with gD plus IC31^® conferred 80–100% protection against an otherwise lethal vaginal HSV-2 challenge with amelioration of viral replication and disease severity in the vagina. These results warrant further exploration of IC31^® for induction of protective immunity against genital herpes and other sexually transmitted infections.     

Freeze‐dried human serum albumin improves the adherence and proliferation of mesenchymal stem cells on mineralized human bone allografts

Mineralized scaffolds are widely used as bone grafts with the assumption that bone marrow derived cells colonize and remodel them. This process is slow and often unreliable so we aimed to improve the biocompatibility of bone grafts by pre‐seeding them with human mesenchymal stem cells from either bone marrow or dental pulp. Under standard cell culture conditions very low number of seeded cells remained on the surface of freeze‐dried human or bovine bone graft or hydroxyapatite. Coating the scaffolds with fibronectin or collagen improved seeding efficiency but the cells failed to grow on the surface until the 18th day. In contrast, human albumin was a very potent facilitator of both seeding and proliferation on allografts which was further improved by culturing in a rotating bioreactor. Electron microscopy revealed that cells do not form a monolayer but span the pores, emphasizing the importance of pore size and microstructure. Albumin coated bone chips were able to unite a rat femoral segmental defect, while uncoated ones did not. Micro‐hardness measurements confirmed that albumin coating does not influence the physical characteristics of the scaffold, so it is possible to introduce albumin coating into the manufacturing process of lyophilized bone allografts. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:489–496, 2012