A pathological study of arterial prostheses surgically excised after overt clinical infection.

Infection caused regarding vascular grafts in vascular surgery still remains a major problem. To reduce this problem and the complications which follow, the surgeon must be able to apply the best surgical management and also be confident with the vascular substitute used. There are two important factors to be considered: the biomaterial must have low propensity to infection and good stability if and when infected. In an attempt to verify this problem, 93 vascular grafts surgically excised for overt infection were examined. Techniques used for examinations were gross morphology, histopathology and scanning electron microscopy (SEM) evaluation. There were 23 human umbilical vein (HUV) grafts, 51 Dacron grafts and 19 expanded polytetrafluoroethylene (ePTFE) grafts. Histopathological signs of infection were absent in 57% of the ePTFE and Dacron grafts and in 17.4% of the HUV grafts. The latter were more heavily histologically infected and in some cases the walls were destructed. Histopathological signs of infection were seen on all the prosthetic walls in 36% of all the specimens and were mainly on the external portion of the grafts for the remaining prostheses. Bacteria were seen in respectively 21.7, 15.7 and 20% of the HUV, Dacron and ePTFE grafts with the Gram stain and in 86.9, 84.3 and 94.7% with SEM. The implantation period was shorter for the bioprostheses compared to that of the synthetic grafts because of the site and the indication of implantation. The stability of the bioprostheses was lower compared to that of the synthetic grafts when infected, leading to a breakdown of the wall along the length of the graft. The infection was found on the external capsule of the grafts rather than on the luminal surface.     

Neuropsychological effects of hyperbaric oxygen therapy in cerebral palsy

We conducted a double-blind placebo study to investigate the claim that hyperbaric oxygen treatment (HBO2) improves the cognitive status of children with cerebral palsy (CP). Of 111 children diagnosed with CP (aged 4 to 12 years), only 75 were suitable for neuropsychological testing, assessing attention, working memory, processing speed, and psychosocial functioning. The children received 40 sessions of HBO2 or sham treatment over a 2-month period. Children in the active treatment group were exposed for 1 hour to 100% oxygen at 1.75 atmospheres absolute (ATA), whereas those in the sham group received only air at 1.3 ATA. Children in both groups showed better self-control and significant improvements in auditory attention and visual working memory compared with the baseline. However, no statistical difference was found between the two treatments. Furthermore, the sham group improved significantly on eight dimensions of the Conners' Parent Rating Scale, whereas the active treatment group improved only on one dimension. Most of these positive changes persisted for 3 months. No improvements were observed in either group for verbal span, visual attention, or processing speed.     

Biostability, inflammatory response, and healing characteristics of a fluoropassivated polyester-knit mesh in the repair of experimental abdominal hernias

The present study was undertaken to validate the benefits of a fluoropolymer treatment on the biostability, inflammatory response, and healing characteristics of a polyester mesh used for hernia repair, the Fluoromesh, as compared to a commercial monofilament-knit polypropylene mesh, Marlex, used as the control. Both were implanted for the repair of surgically induced abdominal hernias in piglets for prescheduled durations of implantation of 4, 15, and 60 days. The mesh and surrounding tissue were harvested at the sacrifice for the bursting strength and inflammatory response measurements in terms of alkaline and acid phosphatase secretion in the tissue, and for histological observations of the healing sequence and tissue thickness measurements by histomorphometric techniques. After cleaning to remove adherent tissue, the presence of the fluoropolymer at the surface of the mesh was detected using SEM and ESCA. The results demonstrated greater mechanical reinforcement and tissue development for the Fluoromesh than for the polypropylene mesh. The healing performance of the Fluoromesh was attributed to a more intense chronic inflammatory reaction early after implantation that stimulated significantly greater tissue ingrowth and integration. The concentration of fluoropolymer at the surface of the mesh was masked as a result of biological species adsorption. Textile analysis revealed that the Fluoromesh was dimensionally more stable in vivo than the polypropylene control mesh, which demonstrated stretching in the weft direction and shrinking in the warp direction during implantation.     

Venous homografts as femoro-popliteal bypasses or as vascular access routes in chronic hemodialysis

Saphenous vein homografts preserved by freezing at 40 degrees C in the presence of antibiotics for periods of as much as six months were implanted as part of a clinical evaluation program. Candidates included one requiring femoro-popliteal reconstruction with two separate bypass procedure and reoperations for thrombosis and false aneurysm in the left limb as well as 23 maintenance hemodialysis patients (32 arteriovenous blood access shunts for a total of 424 patient-months). Explanted veins used as femoro-popliteal bypasses were examined after collection incidental to reoperations and autopsy. In-vivo dwell time varied between 7 and 51 months. The femoro-popliteal by-passes exhibited calcification and sclerosis. The dialysis access shunts had average service lives of about a year; 21 were replaced because of thrombosis, 10 were stenosed, 7 had aneurysms and necrosis was present in six. Although this implant provides a workable alternative approach to vascular reconstruction, the rapid degeneration of such veins in vivo is a limitation.     

Clinico-biological markers for the prognosis of status epilepticus in adults

Journal of Neurology - Prediction of mortality, functional outcome and recovery after status epilepticus (SE) is a challenge. Biological and clinical markers have been proposed to reflect the brain...     

Neuron Specific Enolase,S100-beta protein and progranulin as diagnostic biomarkers of status epilepticus

Journal of Neurology - Status epilepticus (SE) is a life-threatening prolonged epileptic seizure. A rapid diagnosis is fundamental to initiate antiepileptic treatment and to prevent the development...     

The roots of modern justice: cognitive and neural foundations of social norms and their enforcement

Among animals, Homo sapiens is unique in its capacity for widespread cooperation and prosocial behavior among large and genetically heterogeneous groups of individuals. This ultra-sociality figures largely in our success as a species. It is also an enduring evolutionary mystery. There is considerable support for the hypothesis that this facility is a function of our ability to establish, and enforce through sanctions, social norms. Third-party punishment of norm violations ("I punish you because you harmed him") seems especially crucial for the evolutionary stability of cooperation and is the cornerstone of modern systems of criminal justice. In this commentary, we outline some potential cognitive and neural processes that may underlie the ability to learn norms, to follow norms and to enforce norms through third-party punishment. We propose that such processes depend on several domain-general cognitive functions that have been repurposed, through evolution's thrift, to perform these roles.     

Initial infectious dose dictates the innate, adaptive, and memory responses to influenza in the respiratory tract

Factors from the virus and the host contribute to influenza virus pathogenicity and to the development of immunity. This study thoroughly examined the effects of an initial infectious dose of virus and unveiled new findings concerning the antiviral and inflammatory responses, innate and adaptive immunity, memory responses, and protection against secondary heterologous infection. Our results demonstrated that the initial infectious dose significantly affects the gene expression of antiviral (IFN-β) and inflammatory (TNF-α, IL-6, IL-1β) cytokines and of enzymes involved in nitrosative/oxidative stress (iNOS, HO-1, NQO1) early in the response to influenza. This response correlated with significantly increased recruitment of innate immune cells into the lungs of infected mice. We showed that this response also alters the subsequent accumulation of activated IFN-γ(+) CD44(hi) CD62L(lo) influenza-specific CD8(+) T cells into the lungs of infected mice through increased T cell-recruiting chemokine gene expression (CCL3, CCL4, CCL5, CXCL10). Furthermore, we demonstrated that the initial infectious dose determines the generation and the distribution of memory CD8(+) T cell subsets without affecting trafficking mechanisms. This impacted on immune protection against heterologous infection. Lastly, we showed that the effects on innate and adaptive immunity were not dependent on influenza strain or on the genetic background of the host. Collectively, our data show for the first time and in detail that the initial infectious dose of influenza determines the development of several aspects of antiviral immunity. This study provides new insights on virus-host interaction in the generation of the global immune response to influenza.