Acute effects of ketamine on memory systems and psychotic symptoms in healthy volunteers.

N-methyl-D-aspartate (NMDA) receptor antagonists have been demonstrated to induce schizophrenia-like symptoms and cognitive impairment in humans. The NMDA receptor has been strongly implicated in memory, but research to date on the effects of NMDA antagonists has examined only some aspects of human memory functions. This study used a double-blind, placebo-controlled, independent groups design with 54 healthy volunteers to examine the effects of infusions of two doses (0.4, 0.8 mg/kg) of the NMDA antagonist ketamine upon the five human memory systems, aspects of executive functioning and schizophrenia-like and dissociative symptoms. Ketamine produced a dose-dependent impairment to episodic and working memory and a slowing of semantic processing. Ketamine also impaired recognition memory and procedural learning. Attention, perceptual priming and executive functioning were not affected following the drug. In addition, ketamine induced schizophrenia-like and dissociative symptoms, which were not correlated with the cognitive measures. These data suggest that, in humans, ketamine produces a selective pattern of impairments to working, episodic, and procedural memory but not to perceptual priming, attention or aspects of executive functioning.     

A phase I trial with two human monoclonal antibodies (hMAb 2F5, 2G12) against HIV-1.

OBJECTIVE: To study the safety, immunogenicity and pharmacokinetics of two intravenously administered human monoclonal antibodies (hMAb 2F5, 2G12) against HIV-1 in humans. DESIGN: Open label clinical phase I trial. SETTING: Primary institutional care. PATIENTS: Seven HIV-1-infected healthy volunteers with > or = 500 x 10(6)CD4 cells/l and < or = 10,000 HIV-1 RNA copies/ml, not treated with highly active antiretroviral therapy (HAART), entered and finished the study. INTERVENTIONS: and main outcome measures: Eight separate infusions of the hMAb were administered over a 4-week period (total dose 14 g). The safety was assessed by physical examination, blood chemistry, complete blood cell count and recording adverse events. 2F5 and 2G12 plasma levels were determined prior to and at the end of each infusion and during the follow-up period of 22 weeks. RESULTS: No clinical or laboratory abnormalities were observed throughout the study. The median distribution half-life (t(1/2 alpha)) of 2F5 and 2G12 was 1.02 (range, 0.77-1.47) days and 2.49 (range, 0.92-4.59) days, respectively. The elimination half-life (t(1/2 beta)) was calculated to be 7.94 (range, 3.46-8.31) days for 2F5 and 16.48 (range, 12.84-24.85) days for 2G12. The median plasma concentration immediately after the first infusion was 216 microg/ml (range, 158-409 microg/ml) for 2F5 and 238 microg/ml (range, 197-402 microg/ml) for 2G12. Multiple infusions resulted in maximum plasma concentrations of 374 microg/ml (range, 304-700 microg/ml) and 605 microg/ml (range, 479-897 microg/ml) for 2F5 and 2G12, respectively. CONCLUSIONS: This study showed that the hMAb 2F5 and 2G12 are safe and well tolerated by HIV-1-infected subjects.     

Differentiation and function of Th17 T cells

IL-17-producing T cells have recently been classified as a new effector T-cell subset, termed Th17, which is distinct from Th1, Th2 and Treg subsets. There has been much progress in the past year, leading to identification of the molecular mechanisms that drive differentiation of Th17 T cells. This has helped to clarify many aspects of their role in host defense as well as in autoimmunity. Nevertheless, many intriguing questions remain to be answered regarding the regulation of Th17-mediated responses as well as their interactions with the other T-cell subsets. Furthermore, the role of pathogens and pathogen-derived molecules in influencing effector T-cell polarization needs to be re-evaluated in the light of the differentiation conditions that favor Th17 T-cell responses.     

Filarial nematode (order: Spirurida) surveillance in urban habitats,in the city of Pécs (Hungary)

Parasitology Research - As part of the seasonal mosquito control activities in the city of Pécs (Baranya County, Hungary), a total of 1123 adult female mosquitoes belonging to 18 species...     

Decreased caveolin-1 in atheroma: loss of antiproliferative control of vascular smooth muscle cells in atherosclerosis

OBJECTIVE: Proliferation of vascular smooth muscle cells (VSMC) is involved in the pathogenesis of primary atherosclerosis and restenosis after angioplasty. On the background of the antiproliferative activities of caveolin-1, the present study focused on the expression of caveolin-1 in proliferating VSMC of human atheroma. METHODS: VSMC were isolated from wild-type (Wt) and caveolin-1 knockout mice (Cav-/-). Proliferation of Wt-VSMC after supplementation of serum or Cav-/-VSMC after adenoviral overexpression of caveolin-1 was documented by either Western blot analysis of the cyclin-dependent kinase (Cdk) inhibitor p27kip1 and the proliferating cell nuclear antigen (PCNA) or BrdU incorporation. Using immunohistochemistry the proliferation of VSMC derived from atheroma of human carotid vessels as well as the expression of caveolin-1 in these cells were investigated ex vivo. RESULTS: Supplementation of serum to Wt-VSMC resulted in an augmented cell cycle entry and a concomitant decrease of caveolin-1 expression. Inversely, adenoviral overexpression of caveolin-1 in Cav-/-VSMC inhibited cellular proliferation. Corresponding to these in vitro data, the expression of caveolin-1 was significantly decreased in proliferating VSMC of human atheroma. CONCLUSION: The proliferation of VSMC in vitro and in human atheroma is associated with a decrease of caveolin-1 expression. These data suggest that the loss of antiproliferative control by caveolin-1 plays a pivotal role in VSMC proliferation in atherosclerosis.     

Vascular changes and black hole phenomenon after coronary brachytherapy: a pathologically distinct entity

Restenosis remains an important issue even after coronary brachytherapy despite its efficacy in the treatment for in-stent restenosis. The acute and chronic changes in vascular wall are unique following brachytherapy. The restenotic tissue post coronary brachytherapy is relatively acellular and appears echolucent in intravascular ultrasound examination. This is dubbed the "black hole" phenomenon. Despite the similarity in the mode of action of brachytherapy and drug eluting stent implantation, the black hole phenomenon seems to be uncommon after drug-eluting stent implantation except in those patients who have had prior brachytherapy, bare-metal placement and after treatment of saphenous venous graft stenosis. It is possible that not all neointima in stents are created equal. We should propose that neointima be considered primary neointima if it forms after bare metal stenting, secondary neointima if it forms after CBT or DES, and perhaps tertiary if after combined CBT and DES. This type of classification may prove useful for research or clinical purposes. Almost certainly black hole phenomenon results from a modified neointima. However, we do not know whether this is the same restenotic tissue that was present before CBT but just depleted of its cellular element secondary to autolysis or a newly formed tertiary neointima? It is also not clear whether the changes in vascular wall and restenosis are similar after CBT or drug-eluting stent placement. However, there are some unique vascular changes that seem to be common after both of these procedures.