A Cell-Free Collagen Type I Device for the Treatment of Focal Cartilage Defects

The purpose of this study was to evaluate the potential value of a cell-free collagen type I gel plug for the treatment of focal cartilage defects. Cellular migration and proliferation was addressed in vitro, and the formation of repair tissue in a nude mouse-based defect model. A cell-free plug made of collagen type I was placed in the center of an incubation plate. Surrounding space was filled with a collagen type I gel (Arthro Kinetics, Esslingen, Germany) seeded with 2 × 10⁵ human articular chondrocytes/mL gel. After cultivation for up to 6 weeks in vitro, samples were subject to histological and immunohistochemical staining and gene expression analysis. Subsequently, chondral defects of human osteochondral blocks were treated with the plug, and specimens were cultivated subcutaneously in nude mice for 6 weeks. The repair tissue was evaluated macroscopically, and collagen type II production was investigated immunohistochemically. In vitro, morphology of immigrated cells did not show any differences, as did collagen type II gene expression. After 4 weeks, the plug was homogeneously inhabited. After 6 weeks of cultivation in nude mice, collagen gel plug treatment led to a macroscopically excellent repair tissue. Histological staining revealed a tight bonding, and the collagen gel plug started to be remodeled. We conclude that the novel collagen gel plug device offers an environment favorable for the migration of articular chondrocytes and leads to a good-quality repair tissue in the nude mouse model. The arthroscopic transplantation of a collagen gel plug may be one option in the treatment of focal cartilage defects.     

Ten reasons to oppose the criminalization of HIV exposure or transmission

Recent years have seen a push to apply criminal law to HIV exposure and transmission, often driven by the wish to respond to concerns about the ongoing rapid spread of HIV in many countries. Particularly in Africa, some groups have begun to advocate for criminalization in response to the serious phenomenon of women being infected with HIV through sexual violence or by partners who do not reveal their HIV diagnoses to them. While these issues must be urgently addressed, a closer analysis of the complex issues raised by criminalization of HIV exposure or transmission reveals that criminalization is unlikely to prevent new infections or reduce women's vulnerability to HIV. In fact, it may harm women rather than assist them, and have a negative impact on public health and human rights. This paper is a slightly revised version of a document originally released in December 2008 by a coalition of HIV, women's and human rights organizations. It provides ten reasons why criminalizing HIV exposure or transmission is generally an unjust and ineffective public policy. The obvious exception involves cases where individuals purposely or maliciously transmit HIV with the intent to harm others. In these rare cases, existing criminal laws – rather than new, HIV-specific laws – can and should be used.     

Antwort auf den Leserbrief von Valhaus et al. Zu unserer Kasuistik „Kardiogener Schock 4 Stunden nach akut-PTCA bei Hinterwandinfarkt“

Ohne Zusammenfassung     

Reversible binding of heparin to the loop peptide of endotoxin neutralizing protein

Endotoxin neutralizing protein (ENP) from Limulus polyphemus is an amphipathic, 11.8 kDa protein with an isoelectric point of 10.2. ENP neutralizes lipopolysaccharide (LPS) and possesses antibacterial activity against Gram-negative bacteria. Heparin binds to ENP and blocks its LPS-neutralizing activity. The relative blocking activity of heparin is equal to low molecular weight heparin and polyanetholsulfonic acid > heparan sulfate > chondroitin sulfate A > chondroitin sulfate C. Endoproteinase Glu-C hydrolysis of recombinant ENP results in four major peptides, three of which are seen following separation on reversed phase HPLC. Heparin binds to the loop peptide (31-72), which includes the heparin binding consensus sequence XBBXBX between the two cysteine residues of ENP. When heparin is added to the digest and then applied to a C18 column, the loop peptide is bound; however, it dissociates and elutes with either 5 M NaCl or 0.1 M sodium phosphate, demonstrating reversible binding to heparin. LPS and lipid A both bind to the loop peptide and remove it from digests of ENP; however, neither complex could be dissociated by salt or sodium phosphate. Heparin, LPS, and lipid A individually bind to the same site on ENP.     

The pathophysiology of chronic subdural hematoma revisited: emphasis on aging processes as key factor

GeroScience - Chronic subdural hematoma (CSH) affects mostly elderly subjects. Previously, pathophysiological concepts suggested that CSH is secondary to degradation of subdural collections of...     

Too little aspirin for secondary prevention after acute myocardial infarction in patients at high risk for cardiovascular events: Results from the MITRA study

Background

A meta-analysis of randomized trials has shown a significant reduction of mortality rate in patients receiving aspirin for secondary prevention after acute myocardial infarction (AMI). However, a significant number of patients do not receive aspirin after AMI. Little is known about why aspirin is withheld or the long-term outcome of these patients today.

Methods

The Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) registry is a multicenter registry of patients with AMI in Germany.

Results

Of 4902 patients, 509 (10%) did not receive aspirin at the time of discharge from the hospital. The mean follow-up period for these patients was 17 months. Relative contraindications to aspirin were significantly associated with the withholding of aspirin (in-hospital bleeding: odds ratio [OR], 3.56; 95% CI, 1.86-6.80; history of peptic ulcer: OR, 2.49; 95% CI, 1.62-3.83). Absolute contraindications to aspirin were rare (2.2%). Other medications of proven benefit were also given less often in these patients (β-blockers: 49.0% vs 61.9%, P <.001; angiotensin-converting enzyme inhibitors: 65.6% vs 70.2%, P = .06; statins: 12.2% vs 15.1%, P = .10). Patients who were not given aspirin were at high risk for vascular events. They were more likely to have a history of prior AMI (OR, 1.34; 95% CI, 1.02-1.79), were in critical clinical condition at admission more often (cardiogenic shock: OR, 1.98; 95% CI, 1.09-3.56; overt heart failure: OR, 1.6; 95% CI, 1.05-2.3), and received acute revascularization less often (OR, 1.32; 95% CI, 1.05-1.67). The 1-year mortality was 2-times higher in patients who did not receive aspirin than in patients who did receive aspirin (16.5% vs 8.3%, P <.001). A significant association of withheld aspirin at discharge with a higher long-term mortality rate was confirmed with multivariate analysis (OR, 1.62; 95% CI, 1.15-2.29).

Conclusions

Ten percent of patients who sustained an AMI did not receive aspirin at the time of hospital discharge. Most of these patients were at high risk for cardiovascular events. Withheld aspirin was significantly associated with higher mortality rate during follow up.