Murine polyomavirus-like particles induce maturation of bone marrow-derived dendritic cells and proliferation of T cells

We analysed the effects of murine polyomavirus-like particles (PLPs) on bone marrow-derived dendritic cells (BMDCs) and T cells in vitro. BMDCs activated with PLPs up-regulated CD40, CD80, CD86 and major histocompatibility complex (MHC) class II surface markers and produced proinflammatory cytokines. Chimeric PLPs [expressing the ovalbumin (OVA)-peptides OVA(257-264) or OVA(323-339)], but not wildtype PLPs, activated OVA-specific CD8 T cells and OVA-specific CD4 T cells, respectively, indicating both MHC class I and II presentation of the peptides by antigen-presenting cells. Our results suggest that PLPs may be used as vaccine adjuvants priming dendritic cells to induce potent T cell responses.     

Augmented reality–assisted craniofacial reconstruction in skull base lesions — an innovative technique for single-step resection and cranioplasty in neurosurgery

Neurosurgical Review - Defects of the cranial vault often require cosmetic reconstruction with patient-specific implants, particularly in cases of craniofacial involvement. However, fabrication...     

Cocaine use in Europe - a multi-centre study. Methodology and prevalence estimates

An increase in the use of cocaine and crack in several parts of Europe has raised the question whether this trend is similar to that of the USA in the 1980s. However, research in the field of cocaine use in Europe has been only sporadic. Therefore, a European multi-centre and multi-modal project was designed to study specific aspects of cocaine and crack use in Europe, in order to develop guidelines for public health strategies. Data on prevalence rates were analysed for the general population and for specific subgroups. Despite large differences between countries in the prevalence of cocaine use in the general population, most countries show an increase in the last few years. The highest rate with a lifetime prevalence of 5.2% was found for the United Kingdom, although with a plateau effect around the year 2000. With regard to specific subgroups, three groups seem to show a higher prevalence than the general population: (1) youth, especially in the party scene; (2) socially marginalized groups, such as homeless and prostitutes or those found in open drug scenes; (3) opiate-dependent patients in maintenance treatment who additionally use cocaine. Specific strategies need to be developed to address problematic cocaine use in these subgroups.     

Bone loss is detected more frequently in patients with ankylosing spondylitis with syndesmophytes

OBJECTIVE: To define the relationship between bone growth (syndesmophytes) and bone loss (osteoporosis) in ankylosing spondylitis (AS). METHODS: Bone mineral density (BMD) at the spine, hip, and radius was measured by dual-energy x-ray absorptiometry (DEXA), dual-energy quantitative computed tomography (DEQCT), and peripheral quantitative computed tomography (pQCT) in 103 patients with AS. Radiographs of the lumbar spine were used to detect syndesmophytes. Patients were divided in 3 groups according to disease duration. RESULTS: Osteopenia at the hip and spine was found by DEXA in 56% and 41%, respectively, of the patients with disease duration < 5 years (n = 27), with an additional 11% and 15% having osteoporosis. In patients with a longer disease duration, > 10 years (n = 28), 29% were osteoporotic at the hip and only 4% at the lumbar spine. In contrast, using spinal DEQCT, 59% of patients with early disease were found to be osteopenic; 36% of patients with long-standing disease were osteopenic and 18% were osteoporotic. More than half the patients (55%) had syndesmophytes (n = 55). With spinal DEQCT there were more patients with syndesmophytes (63%) in the group with reduced bone density than in the group without (45%). This was similar with DEXA measurements at the hip, where 31% compared to 14% had osteoporosis, respectively. Osteocalcin was elevated in 34% of patients, but was not associated with disease activity or BMD. CONCLUSION: The majority of patients with AS had reduced bone density. The method of bone density measurement is critical and should be different depending on disease duration. The finding that more patients with syndesmophytes had reduced bone density than those without suggests that bone growth and bone loss occur in parallel, and the role of inflammation in this process warrants further investigation.     

Intracellular beta-blockade: overexpression of Galpha(i2) depresses the beta-adrenergic response in intact myocardium

OBJECTIVE: Increased levels of inhibitory G proteins have been observed in heart failure, but their physiological relevance in mediating the reduced beta-adrenergic response is largely unknown. METHODS: To evaluate the functional consequences of Galpha(i2) overexpression, we studied myocardial contraction in intact isometric contracting cardiac rabbit trabeculae and isolated myocytes after adenovirus-mediated gene transfer of Galpha(i2). RESULTS: Neither Galpha(i2) nor lacZ (control) overexpression altered baseline contractile force. After 72 h of continuous contractions, developed force (F(dev)) increased after addition of 1 microM isoproterenol by 28.5+/-9.7 mN/mm(2) in the control group, which was unchanged from the initial response at t=0 h (23.7+/-3.8 mN/mm(2)). In sharp contrast, in preparations transfected with AdGalpha(i2), the response to isoproterenol was significantly attenuated (5.9+/-2.0 vs. 27.6+/-4.2 mN/mm(2), t=72 vs. 0 h, respectively, P<0.01). In a primary culture of transfected isolated myocytes from a nearly identical baseline, isoproterenol increased cell shortening by 3.1+/-0.6% in the lacZ transfected myocytes, but only by 1.3+/-0.5% in Galpha(i2) transfected myocytes (t=72 h, P<0.01). In Galpha(i2) transfected myocytes, pertussis toxin restored beta-adrenergic responsiveness, indicating specificity of attenuation by the transgene. CONCLUSIONS: Overexpression of Galpha(i2) attenuates the positive inotropic effects of beta-adrenergic stimulation in myocardium. In addition, the method we developed allows investigation of a causal link between altered protein expression and subsequent alterations in contractile function in a physiological relevant in vitro manner.     

The variability of atlas-based targets in relation to surrounding major fibre tracts in thalamic deep brain stimulation

Background

In essential tremor (ET), the main target for deep brain stimulation (DBS) is the thalamic ventralis intermedius nucleus (Vim). This target cannot be identified on conventional magnetic resonance imaging (MRI). Therefore, targeting depends on probabilistic coordinates derived from stereotactic atlases. The goal of our study was to investigate the variability of atlas-based Vim targets in relation to surrounding major fibre tracts.

Methods

With the MRI and computed tomography (CT) scan data of ten patients who underwent DBS, we planned atlas based Vim targets in both hemispheres. We also performed deterministic fibre-tracking with diffusion tensor imaging (DTI) of the dentato-rubro-thalamic tract (DRTT), pyramidal tract (PT) and lemniscus medialis (LM) in all 20 hemispheres. Subsequently, we measured the distance from the atlas-based Vim target to each tract along the medial/lateral (x-coordinate), anterior/posterior (y-coordinate) and superior/inferior axis (z-coordinate).

Results

Seventeen out of 20 DRTTs could be depicted with our standardised DTI/fibre-tracking parameters. The PT and the LM could be displayed in all 20 hemispheres. The atlas-based Vim target was found inside the DRTT in 11 (concerning the x-coordinate) and 10 hemispheres (concerning the z-coordinate). Regarding the anterior/posterior direction, the target was posterior to the DRTT in 11 cases. In 19 hemispheres the Vim target was located medial and superior to the PT and in 17 hemispheres posterior to it. Concerning the LM, the Vim target was found inside the LM in 16 (regarding the x-coordinate) and in 14 cases (regarding the z-coordinate). In eight cases it was located inside and in 12 cases anterior to the LM concerning the y-coordinate.

Conclusions

We found a considerable variability of the location of atlas-based target points of the ventralis intermedius nucleus in relation to neighbouring major fibre tracts in individual patients. These results suggest that individualised targeting to structures not directly visible on conventional MRI is necessary.