Newly developed hybrid suture without lubricant: noninvasive in vivo assessment of biocompatibility with multiparametric MR imaging.

Magnetic resonance imaging (MRI) and magnetic resonance (MR) relaxometry were used to assess noninvasively the tissue response of a new uncoated hybrid braided suture made from a combination of ultra-high-molecular-weight polyethylene (UHMWPE) and polyester (polyethylene terephthalate) (PET) yarns in comparison to a silicone impregnated braided 100% polyester (PET) control suture (Ticron). Both biomaterials were monitored for a period of 30 days following implantation in both incised and nonincised paravertebral rabbit muscles. In all cases, MR images and relaxometry demonstrated that the hybrid suture elicited either a milder or a similar tissue and cellular response compared to the control suture. These findings were confirmed by conventional histological analysis of the surrounding tissues. They also demonstrated that the hybrid suture promoted faster healing in terms of collagen infiltration between the yarns and individual filaments. This milder inflammatory reaction and improved biocompatibility represent a real advantage in the healing performance of sutures for cardiac and vascular surgery, and support the need for continued research and development of hybrid structures. This study also demonstrated the ability of MRI techniques to noninvasively evaluate the biocompatibility of biomaterials. By extending the capacity of MR diagnostic tools from patients to experimental animals, it is now possible to validate the healing performance of foreign materials with statistical reliability and fewer animals.     

Biocompatibility studies of the Anaconda stent-graft and observations of nitinol corrosion resistance.

PURPOSE: To validate the deployment, in vivo performance, biostability, and healing capacity of the Anaconda self-expanding endoprosthesis in a canine aortic aneurysm model. METHODS: Aneurysms were surgically created in 12 dogs by sewing a woven polyester patch onto the anterior side of the thoracic or abdominal aorta. Anaconda prostheses were implanted transfemorally for prescheduled periods (1 or 3 months). Aneurysm exclusion and stent-graft patency were monitored angiographically. Healing was assessed with histological analysis and scanning electron microscopy (SEM). Textile analysis determined the physical and chemical stability of the woven polyester material, while the biostability of the nitinol wires was evaluated with SEM and spectroscopy. RESULTS: All prostheses were intact at explantation. After 1 month, endothelial-like cells were migrating in a discontinuous manner both proximally and distally over the internal collagenous pannus at the device-host boundary. After 3 months, endothelialization had reached the midsections of the devices, with a thicker collagenous internal capsule. Patches of endothelial-like cells were sharing the luminal surface with thrombotic deposits. However, the wall of the device at the level of the aneurysm was generally poorly healed, with multiple thrombi scattered irregularly over the luminal surface. The polyester fabric was intact except for some filaments that were ruptured adjacent to the sutures and some abrasion caused by the nitinol wires. No evidence of corrosion was found on the nitinol stents. CONCLUSIONS: This Anaconda stent-graft has demonstrated its ability to exclude arterial aneurysms. The device used in this study was an experimental prototype, and the manufacturer has incorporated new immobilization features into the model for clinical use. The constituent materials appear to be suitable in terms of biocompatibility, biofunctionality, and short-term durability.     

Diagnosis of the multiple effect of selenium nanoparticles decorated by Asteriscus graveolens components in inhibiting HepG2 cell proliferation

Using plant bio-components for Designing green metal nanoparticles was considered as one of the most important methods in nanomedical application field due to their eco-friendly, cheap source, easily obtainable and having a high detection result. In this report, we fabricated eco-friendly engineering and cost-effective technique for green selenium nanoparticles from 0.01 M H₂SeO₃ solution using Asteriscus graveolens leaves extract as reducing and a capping agent at ambient temperature. Spectral techniques have been used to identify the formatted Selenium nanoparticles such as UV–Vis, pH, XPs, FT-IR, XRD, LDS, Z.P, EDS, TEM and AFM spectroscopy, which showed a size of 20 nm with spherical shape. Herein, the multi-effect of decorated Se-NPs surface have been evaluated, firstly on the hemolysis that showed completely hemocompatibility. Cytotoxicity assay showed that Se-NPs have a high selective effect on the HepG2 apoptosis and which proved by phase-contrast microscopy. Furthermore, the effect of nanoparticles on the action of the mechanism internal revealed that Se-NPs significantly and rapidly increased the level of reactive oxygen species and lipid peroxidation, while caused decreased the potential of mitochondrial membrane and glutathione level, which they together responsible on regulating the HepG2 cells fate. Furthermore, Flow cytometry analysis gave high values about S and G2/M phases of cell cycle resulting from Se-NPs effectiveness. In the end, with all the recorded information that has been measured in this study, this report provides a suitable and effective pathway for the green fabrication of Se-NPs decorated by biomolecules having high anticancer inhibited.     

Partial thrombosis of the inferior vena cava in a patient with non-Hodgkin lymphoma and history of lumbar spine surgery

Complete or partial thrombosis of the inferior vena cava is usually due to pre-existing malformation of the vessel, malignant tumors, ascending thrombosis, or thrombophilic disorders. We report the case of an 81-year-old woman, in whom a partial thrombosis of the vena cava was observed in the CT scan when re-staging was performed after six cycles of R-CHOP because of high-grade malignant non-Hodgkin lymphoma. Before chemotherapy was started, the patient had undergone an operation of the lumbar spine using cement augmentation. Retrospective analysis showed that cement had penetrated a segmental vein and spilled into the vena cava leading to formation of an adhering blood thrombus. The patient was free of symptoms and anticoagulation was started. Spillage of cement frequently occurs in the process of vertebroplasty and kyphoplasty and may result in serious sequelae. As these procedures are increasingly being used, physicians should be aware of these complications if a patient presents with thrombosis of the caval vein or signs of pulmonary embolism.     

Long-term outcomes following percutaneous tracheostomy using the Griggs technique

Percutaneous tracheostomy is commonly performed in the intensive care unit. This study assesses the long-term outcomes following percutaneous tracheostomy using the Griggs technique. We carried out a prospective observational cohort study. Two hundred and eight patients who had undergone percutaneous tracheostomy between 1 September 1996 and 31 July 2000 and who were alive at least six months following the procedure, were included in the study. Median follow-up was at 30 months. All patients were sent questionnaires regarding relevant symptoms. One hundred and six (51%) responded and were invited for further follow-up. Forty-three (20.6%) patients underwent scar evaluation by the investigators and 41/208 (19.7%) underwent spirometry. Of the responders, 38% complained of some degree of voice change and 12% complained of ongoing severe cough. Thirty-one per cent complained of shortness of breath, with more than half of these having concomitant heart or lung disease, which may explain this. Eighty-one per cent of patients had minimally visible or a visible but neat scar. Eight patients (8/41 (19.5%)) had some evidence of upper airway obstruction on spirometry, but only 2/41 (5% of patients) were symptomatic (stridor or shortness of breath). We conclude that percutaneous tracheostomy using the Griggs technique has an acceptable long-term complication rate.     

Ligand discovery using small molecule microarrays

Small molecule microarrays have recently been used to identify ligands for several proteins, and several themes regarding screening strategies and limitations have emerged. In this review, some of the technical issues related to the manufacture and screening of small molecule microarrays, as well as prospects for small molecule microarrays in several areas of drug discovery and chemistry, are discussed.     

Low-high season variation in Plasmodium falciparum erythrocyte binding antigen 175 (eba-175) allelic forms in malaria endemic area of Burkina Faso

Objective  To assess the impact of seasonal variation on the distribution of the eba- 175 allelic forms in the area where malaria transmission is markedly seasonal.
Methods  Blood samples were collected from 291 and 239 children under 5 years of age during the low and the high malaria transmission season, respectively, in four villages named Dawelgué, Kounda, Tanghin and Watenga of Saponé Health District, then screened for eba 175 F- and C- alleles by nested PCR analysis.
Results  F- alleles were more prevalent than C-alleles in the low [0.66 vs. 0.34 ( P  < 0.0001)] and high transmission season [0.67 vs. 0.33 ( P  < 0.0001)]. No significant seasonal variation was observed in the distribution of the two alleles. However, according to Sewall Wright rules, the population pairwise F _ST values, between Dawelgué and Tanghin during the low transmission season ( F _{ST_} value = 0.10415, P -value = 0.0090 and during the high season ( F _{ST_} value = 0.08244, P -value < 0.00001), between Tanghin and Watenga during the low season ( F _ST value = 0.07414, P -value = 0.009) indicated a moderate but statistically significant genetic differentiation.
Conclusion  Although there was a moderate but significant genetic differentiation between some study villages at different times of the year, this study result in the seasonal stability of eba- 175 allele's distribution in the study area.