Use of the Flixene vascular access graft as an early cannulation solution.

OBJECTIVE: The primary end points of this study were safety and efficacy of early cannulation of the Flixene graft (Maquet-Atrium Medical, Hudson, NH). Secondary end points were complications and patency. METHODS: This is a prospective single-center nonrandomized study. Study data included patient characteristics; history of vascular access; operative technique; interval between implantation and initial cannulation; complications; and patency at 1 month, 3 months, and every 6 months. Patency rates were estimated by the Kaplan-Meier method. RESULTS: Between January 2011 and September 2013, a total of 46 Flixene grafts were implanted in 44 patients (27 men) with a mean age of 63 years. The implantation site was the upper arm in 67% of cases, the forearm in 11%, and the thigh in 22%. Seven grafts were never cannulated during the study period. Of the remaining 39 grafts, 32 (82%) were successfully cannulated within the first week after implantation, including 16 (41%) on the first day. The median interval from implantation to initial cannulation was 2 days (interquartile range, 1-3 days). The median follow-up was 223.5 days (interquartile range, 97-600 days). Five hematomas occurred, but only one required surgical revision. Primary assisted and secondary patency rates were 65% and 86%, respectively, at 6 months and 56% and 86%, respectively, at 1 year. CONCLUSIONS: This study suggests that cannulation of the Flixene graft within 1 week after implantation is safe and effective. Early cannulation avoids or shortens the need for a temporary catheter. One-year patency rates appeared to be comparable to those achieved with conventional grafts, but long-term follow-up and randomized controlled studies will be needed to confirm this finding.

Improving coronary artery bypass graft durability: use of the external saphenous vein graft support.

Coronary bypass grafting remains the best option for patients suffering from multivessel coronary artery disease, and the saphenous vein is used as an additional conduit for multiple complete revascularizations. However, the long-term vein graft durability is poor, with almost 75% of occluded grafts after 10 years. To improve the durability, the concept of an external supportive structure was successfully developed during the last years: the eSVS Mesh device (Kips Bay Medical) is an external support for vein graft made of weft-knitted nitinol wire into a tubular form with an approximate length of 24 cm and available in three diameters (3.5, 4.0 and 4.5 mm). The device is placed over the outer wall of the vein and carefully deployed to cover the full length of the graft. The mesh is flexible for full adaptability to the heart anatomy and is intended to prevent kinking and dilatation of the vein in addition to suppressing the intima hyperplasia induced by the systemic blood pressure. The device is designed to reduce the vein diameter of about 15-20% at most to prevent the vein radial expansion induced by the arterial blood pressure, and the intima hyperplasia leading to the graft failure. We describe the surgical technique for preparing the vein graft with the external saphenous vein graft support (eSVS Mesh) and we share our preliminary clinical results.

Development of a population-based cost-effectiveness model of chronic graft versus host disease in Spain

Chronic graft-versus-host disease (cGvHD) is the leading cause of late nonrelapse mortality (transplant-related mortality) after hematopoietic stem cell transplant. Given that there are a wide range of treatment options for cGvHD, assessment of the associated costs and efficacy can help clinicians and health care providers allocate health care resources more efficiently. OBJECTIVE: The purpose of this study was to assess the cost-effectiveness of extracorporeal photopheresis (ECP) compared with rituximab (Rmb) and with imatinib (Imt) in patients with cGvHD at 5 years from the perspective of the Spanish National Health System. METHODS: The model assessed the incremental cost-effectiveness/utility ratio of ECP versus Rmb or Imt for 1000 hypothetical patients by using microsimulation cost-effectiveness techniques. Model probabilities were obtained from the literature. Treatment pathways and adverse events were evaluated taking clinical opinion and published reports into consideration. Local data on costs (2010 Euros) and health care resources utilization were validated by the clinical authors. Probabilistic sensitivity analyses were used to assess the robustness of the model. RESULTS: The greater efficacy of ECP resulted in a gain of 0.011 to 0.024 quality-adjusted life-year in the first year and 0.062 to 0.094 at year 5 compared with Rmb or Imt. The results showed that the higher acquisition cost of ECP versus Imt was compensated for at 9 months by greater efficacy; this higher cost was partially compensated for ( 517) by year 5 versus Rmb. After 9 months, ECP was dominant (cheaper and more effective) compared with Imt. The incremental cost-effectiveness ratio of ECP versus Rmb was 29,646 per life-year gained and 24,442 per quality-adjusted life-year gained at year 2.5. Probabilistic sensitivity analysis confirmed the results. The main study limitation was that to assess relative treatment effects, only small studies were available for indirect comparison. CONCLUSION: ECP as a third-line therapy for cGvHD is a more cost-effective strategy than Rmb or Imt.

A new alternative method for testing skin irritation using a fresh human skin model

La dermatite irritative est décrite comme une réaction réversible, non immunologique caractérisée par des lésions d'aspect très variable, allant de la simple rougeur jusqu'à la formation de bulles voire d'une nécrose, accompagnée de prurit ou d'une sensation de brûlure suite à I' application d'une substance chimique. Le teste de prédiction d'irritation cutanée est traditionnellement depuis les années 1940 le Test de Draize. Ce test consiste en l'application d'une substance chimique sur une peau rasée de lapin pendant 4h et de regarder à 24h si des signes cliniques d'irritations sont présents. Cette méthode critiquable autant d'un point de vue éthique que qualitative reste actuellement le teste le plus utilisé. Depuis le début des années 2000 de nouvelles méthodes in vitro se sont développées tel que le model d'épiderme humain recombiné (RHE). Il s agit d'une multicouche de kératinocyte bien différencié obtenu depuis une culture de don d'ovocyte. Cependant cette méthode en plus d'être très couteuse n'obtient au mieux que 76% de résultat similaire comparé au test in vivo humain. Il existe donc la nécessité de développer une nouvelle méthode in vitro qui simulerait encore mieux la réalité anatomique et physiologique retrouvée in vivo. Notre objectif a été de développer cette nouvelle méthode in vitro. Pour cela nous avons travaillé avec de la peau humaine directement prélevée après une abdominoplastie. Celle ci après préparation avec un dermatome, un couteau dont la lame est réglable pour découper l'épaisseur souhaitée de peau, est montée dans un système de diffusion cellulaire. La couche cornée est alors exposée de manière optimale à 1 ml de la substance chimique testée pendant 4h. L'échantillon de peau est alors fixé dans du formaldéhyde pour permettre la préparation de lames standards d'hématoxyline et éosine. L'irritation est alors investiguée selon des critères histopathologiques de spongioses, de nécroses et de vacuolisations cellulaires. Les résultats de ce.tte première batterie de testes sont plus que prometteurs. En effet, comparé au résultat in vivo, nous obtenons 100% de concordance pour les 4 même substances testes irritantes ou non irritantes, ce qui est supérieur au model d épiderme humain recombiné (76%). De plus le coefficient de variation entre les 3 différentes séries est inférieur à 0.1 ce qui montre une bonne reproductibilité dans un même laboratoire. Dans le futur cette méthode va devoir être testée avec un plus grand nombre de substances chimiques et sa reproductibilité évaluée dans différents laboratoires. Mais cette première evaluation, très encourageante, ouvre des pistes précieuses pour l'avenir des tests irritatifs.

Different Storing and Processing Conditions of Human Lymphocytes do not Alter P-Glycoprotein Rhodamine 123 Efflux.

P-glycoprotein (Pgp), a protein codified by Multi Drug Resistance (MDR1) gene, has a detoxifying function and might influence the toxicity and pharmacokinetics and pharmacodynamics of drugs. Sampling strategies to improve Pgp studies could be useful to optimize the sensitivity and the reproducibility of efflux assays. This study aimed to compare Pgp expression and efflux activity by measuring Rhodamine123 (Rh123) retention in lymphocytes stored under different conditions, in order to evaluate the potential utility of any of the storing conditions in Pgp functionality. Our results show no change in protein expression of Pgp by confocal studies and Western blotting, nor changes at the mRNA level (qRT-PCR). No differences in Rh123 efflux by Pgp activity assays were found between fresh and frozen lymphocytes after 24 hours of blood extraction, using either of the two Pgp specific inhibitors (VP and PSC833). Different working conditions in the 24 hours post blood extraction do not affect Rh123 efflux. These results allow standardization of Pgp activity measurement in different individuals with different timing of blood sampling and in different geographic areas. _______________

Heterogeneous products and tests for an appropriate aggregation level considering different qualities: evidence from fresh hake at Barcelona’s wholesale market

[cat] Aquest estudi destaca la importància de considerar un nivell d’agregació adequat en els anàlisis de demanda, ja que treballar utilitzant un nivell d’agregació inadequat pot donar lloc a estimacions esbiaixades. Aquest fet es mostra a través de l’anàlisi de diferents productes de lluç fresc comercialitzats a Mercabarna, el mercat majorista de Barcelona. La literatura sobre la demanda de peix tracta al lluç com un únic producte i espècie. No obstant això, en el mercat espanyol, es comercialitzen molts peixos com a lluç, els quals mostren comportaments molt diferents (des de béns inferiors fins a béns de luxe). Els resultats obtinguts, en concordança amb les observacions empíriques, demostren que l’anàlisi s’ha de realitzar amb un major grau de detall que a nivell d’espècie. Això qüestiona els resultats d’anteriors estudis de demanda i la majoria de les bases de dades, on l’observació del nivell d’agregació adequat dels productes no es té en compte.

Heterogeneous products and tests for an appropriate aggregation level considering different qualities: evidence from fresh hake at Barcelona’s wholesale market

[cat] Aquest estudi destaca la importància de considerar un nivell d’agregació adequat en els anàlisis de demanda, ja que treballar utilitzant un nivell d’agregació inadequat pot donar lloc a estimacions esbiaixades. Aquest fet es mostra a través de l’anàlisi de diferents productes de lluç fresc comercialitzats a Mercabarna, el mercat majorista de Barcelona. La literatura sobre la demanda de peix tracta al lluç com un únic producte i espècie. No obstant això, en el mercat espanyol, es comercialitzen molts peixos com a lluç, els quals mostren comportaments molt diferents (des de béns inferiors fins a béns de luxe). Els resultats obtinguts, en concordança amb les observacions empíriques, demostren que l’anàlisi s’ha de realitzar amb un major grau de detall que a nivell d’espècie. Això qüestiona els resultats d’anteriors estudis de demanda i la majoria de les bases de dades, on l’observació del nivell d’agregació adequat dels productes no es té en compte.

A convenient method for lecithin purification from fresh eggs

The increasing demand for fatty acid-free lecithin required modifications in existing purification methods. In this technical note we describe a purification procedure with the following steps: a) homogenization and extraction of yolks obtained from fresh eggs with acetone, b) solubilization with ethanol and solvent elimination and c) repeated solubilization/precipitation with petroleum ether/acetone. This crude extract was chromatographed on neutral alumina, which was exhaustively washed with chloroform before elution with chloroform:methanol, allowing the sequential separation of fatty acids and lecithin. Chromatographic behavior and mass spectra of the product are presented. This fast procedure yields fatty acid-free lecithin at a competitive cost.

Graft materials in oral surgery: revision

Oral implantology is a common procedure in dentistry, especially for fully or partially edentulous patients. The implants must be placed in the best location from both the aesthetic and functional point of view. Because of this it is increasingly more frequent to resort to regeneration techniques that use substitutes of the bone itself, in order to be able to insert the implants in the most appropriate location. Material and Methodology: A review was performed on the literature from the last ten years based on the following search limitations: "graft materials', 'allograft', 'xenograft', 'autologous graft" and 'dentistry". Results: 241 works were obtained that after reading their respective summaries, they were reduced to 38, and 9 previous works were included in order to summarize the concepts. Discussion: Autologous grafts are the 'gold standard' of the bone regeneration. They have obvious advantages, but they also have drawbacks. This is why allogeneic and xenogeneic tissues are used. The former because of their clear similarity with the recipient's tissue and the latter due to their wide availability. Given that these grafts also have drawbacks, the industry has developed synthetic materials that have properties similar to those of human bone tissue. However, as of today, the ideal material to substitute human bone has not yet been found. In recent years the tendency has been to combine these synthetic materials with the patient's own bone, which is extracted during drilling in implant placement, with bone marrow aspiration, or with bone morphogenetic proteins. Thus the intention is to equip these substances with the osteogenic capacity. Conclusions: There is currently no ideal graft material, with the exception of those materials that come directly from the patient. We hope that in the coming years we will have products that will allow us to perform rehabilitations with better results and provide a better quality of life for our patients, especially those who have more complex situations to resolve, like the patients that are operated on for head and neck cancer

DERIVATIZACIÓN Y CARACTERIZACIÓN ESPECTROSCÓPICA DE UN BIOPOLÍMERO A BASE DE L -LISINA CON ANÁLOGOS DE LA D-BIOTINA: CO -POLI(L-LISINA)-GRAFT -(ε-N-[X-D -BIOTINIL]-L-LISINA)

We report the single-step derivatization reaction of a biopolymer based onL -lysine with D -biotin analogs:Co -poly(L -lysine)-graft-(ε-N -[X-D-biotinyl]-L -lysine) (PLL-X-Biotin). The valeric acid carboxylate of D -biotin is activated to an NHS ester for direct modification of amine groups in proteins and other macromolecules. NHS esters react by nucleophilic attack of an amine in the carbonyl group, releasing the NHS group, and forming a stable amide linkage. NHS-X-Biotin is the simplest biotinylation reagent commercially available. In contrast withD -biotin, it has a longer spacer arm off the valeric acid side chain allowing better binding potential for avidin or streptavidin probes. Derivatization of poly(L -lysine) (PLL) with NHS-X-Biotin led to a copolymer PLL-X-Biotin. UV-Visible, IR-FT and 1H NMR characteristics derived from synthesis are briefly discussed.

Percutaneous core biopsy of palpable breast lesions: accuracy of frozen section histopathological exam in the diagnosis of breast cancer

OBJECTIVE: to evaluate the accuracy of frozen section histopathology from fragments of tissue obtained by percutaneous core needle biopsy of palpable tumors in the diagnosis of breast cancer. METHODS: a cohort study was performed on 57 patients with palpable tumors and suspected breast cancer undergoing percutaneous thick needle core biopsy. The fragments were analyzed by the same pathologist. RESULTS: frozen section diagnosed 16 benign cases (28.6%) and 40 malignant (71.4%), whereas paraffin showed that 15 were benign (26.8%) and 41 malignant (73.2%). Histopathological examinations were concordant in 55 cases and there was one false-negative (6.2%). Statistics rates were: negative predictive value of 93.8%, positive predictive value of 100%, no false-positive (0%), one false negative (6.2%), specificity of 100%, sensitivity of 97 6%; observed agreement = 98.2%; expected agreement = 59.9%, Kappa = 0.955 [ 95% CI = 0.925-0.974, p < 0.01 ]. CONCLUSIONS: frozen section histopathological findings showed excellent correlation with the findings by the technique in paraffin in the fragments of palpable breast tumors obtained by thick needle percutaneous core biopsy (98.2% accuracy). Therefore, in these patients, it was possible to anticipate the diagnosis, staging and the breast cancer treatment planning.

Splenic vein graft for the reconstruction of the mesenteric-portal trunk after gastroduodenopancreatectomy

Resection of the confluence of the superior mesenteric and portal veins has been performed most frequently in the treatment of adenocarcinoma of the pancreas, in view of the reported positive results, but it can also be used in cases of benign pancreatic neolpasias when they are strongly adhered to the mesenteric-portal trunk. Nevertheless, there is no study on the best type of venous grafts for reconstruction of the mesenteric-portal trunk when required. The choice of graft depends on the preference of the surgeon or the institution. This technical note critically discusses the use of the splenic vein as an option for mesenteric-portal trunk reconstruction after gastroduodenopancreatectomy.

Preliminary study of coconut water for graft tissues preservation in transplantation

OBJECTIVE: to verify the effectiveness of coconut water in preserving tissues for transplant. METHODS: Fifty male Wistar rats were randomly distributed in five groups, according to the following preservation solutions for tissue grafts: Group 1: Lactated Ringer; Group 2: Belzer solution; Group 3: mature coconut water; Group 4: green coconut water; Group 5: modified coconut water. In Group 5, the green coconut water has been modified like the Belzer solution. From each animal we harvasted the spleen, ovaries and skin of the back segment. These tissues were preserved for six hours in one of the solutions. Then, the grafts were reimplanted. The recovery of the function of the implanted tissues was assessed 90 days after surgery, by splenic scintigraphy and blood exame. The implanted tissues were collected for histopathological examination. RESULTS: The serum levels did not differ among groups, except for the animals in Group 5, which showed higher levels of IgG than Group 1, and differences in relation to FSH between groups 1 and 2 (p <0.001), 4 and 2 (p = 0.03) and 5 and 2 (p = 0.01). The splenic scintigraphy was not different between groups. The ovarian tissue was better preserved in mature coconut water (p <0.007). CONCLUSION: the coconut water-based solutions preserves spleen, ovary, and rat skin for six hours, maintaining their normal function.