Search results for "Preservation"
showing 10 items of 484 documents
An old method for good new cells
2009
The aim of this work was to demonstrate a greater number of viable cells using a micro-surgical in-situ perfusion to collect rat pancreata compared with the pancreas after exsanguination. We used 3 groups of 20 rats. Perfusion was performed by selective cannulation of the left common iliac artery with administration of UW solution at 4 degrees C. Collected pancreata were digested and cells separated by Ficoll gradient were placed in culture to permit adhesion to dishes. Cells were characterized and tested for viability. We observed a gain of about 14% in the number of viable cells compared with those obtained after exsanguination (P < .001 by chi-square).
Flow and Pressure during Liver Preservation under ex situ and in situ Perfusion with University of Wisconsin Solution and Histidine-Tryptophan-Ketogl…
2006
Effective preservation of liver grafts is the first essential step for successful liver transplantation. Insufficient perfusion leads to ischemic-type biliary lesions after transplantation. Perfusion of the graft can be performed either in situ or ex situ, with gravity flow or pressure-controlled. Mainly University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions are used widespread in clinical liver transplantation. Due to a persistent lack of data, we performed this systematic investigation of in situ and ex situ perfusion of liver grafts with HTK (low-viscous) and UW (high-viscous) solutions at different pressure steps on the perfusion solution (gravity flow, 50, …
Rat liver preservation by hypothermic oscillating liver perfusion compared to simple cold storage.
1998
Rat livers were preserved hypothermically for 10 or 24 h in vitro as if for transplantation. Two methods of preservation were compared using physiological and biochemical parameters: simple storage and oscillating perfusion. By measuring the nucleotides after preservation the calculated energy charge was significantly higher after 10 and 24 h of oscillating perfusion compared to the simple storage group. In addition, a significant energy charge loading was demonstrated by 10 h oscillating perfusion compared to the initial value prior to perfusion. The oscillating, computer-controlled perfusion permits continuous monitoring of perfusate temperature, O2 consumption, pCO2, portal vein pressure…
Platform switch versus platform match in the posterior mandible – 1-year results of a multicentre randomized clinical trial.
2014
Objective The purpose of this ongoing randomized study was to assess differences in bone level changes and success rates using implants supporting single crowns in the posterior mandible either with platform matched or platform switched abutments. Material and Methods Patients aged 18 and above, missing at least two teeth in the posterior mandible and with a natural tooth mesial to the most proximal implant site were enrolled. Randomization followed implant placement. Definitive restorations were placed after a minimum transgingival healing period of 8 weeks. Changes in crestal bone level from surgery and loading (baseline) to 12-month post-loading were radiographically measured. Implant su…
Effect of platform switching on crestal bone levels around implants in the posterior mandible: 3 years results from a multicentre randomized clinical…
2016
Objective Evaluation of differences in the clinical performance and crestal bone levels between implants restored with single crowns with platform-matched or platform-switched abutments after 3 years. Material and Methods The study enrolled adult patients missing two or more adjacent teeth in the posterior mandible with natural teeth mesial to the implant site. Randomization followed open-flap implant insertion and the corresponding matching or switching healing abutments placed at surgery. Conventional loading was made with cemented crowns. Clinical follow-up took place annually after loading up to 3 years. Bone level changes were measured in standardized radiographs as the variation in cr…
Cryopreservation of prostate cancer tissue during routine processing of fresh unfixed prostatectomy specimen: demonstration and validation of a new t…
2008
BACKGROUND Most molecular techniques currently require fresh frozen tumor tissue, which in the case of prostatectomy specimen is a challenge to obtain for a variety of intrinsic reasons. Prostate cancers are usually located in the organ periphery and hence meticulous attention has to be paid to the relation between the tumor and the surgical margin. In this article we describe a new technique that allows to obtain fresh frozen tumor material in rather large quantities and without jeopardizing diagnostic accuracy. METHOD An inner triangle, representing roughly 50% of the entire prostate tissue, is removed from native prostatectomy specimen and cryopreserved, leaving the periphery of the orga…
Bone mineral density of the proximal femur after hip resurfacing arthroplasty: 1-year follow-up study
2011
Abstract Background Hip resurfacing arthroplasty (HRA) is considered a bone-preserving procedure and may eliminate proximal femoral stress shielding and osteolysis. However, in addition to implant-related stress-shielding factors, various patient-related factors may also have an effect on bone mineral density (BMD) of the proximal femur in patients with HRA. Thus, we studied the effects of stem-neck angle, demographic variables, and physical functioning on the BMD of the proximal femur in a one-year follow-up. Methods Thirty three patients (9 females and 24 males) with a mean (SD) age of 55 (9) years were included in the study. BMD was measured two days and 3, 6, and 12 months postoperative…
Cranioplasty with autologous bone flaps cryopreserved with Dimethylsulphoxide : does tissue processing matter
2021
Este artículo se encuentra disponible en la siguiente URL: https://www.sciencedirect.com/science/article/abs/pii/S1878875021001625?via%3Dihub En este artículo de investigación también participan: Dolores Ocete, Lucas Aranda, Ana Melero, Antonio J. Guillot, Nuria Yagüe y Carlos Botella. Este es el pre-print del siguiente artículo: Mirabet, V., García, D., Roca, A., Quiroz, A. R., Antón, J., Rodríguez-Cadarso, M., Ocete, D., Aranda, L., Melero, A., Guillot, A. J., Yagüe, N., Guillén, I. & Botella, C. (2021). Cranioplasty with autologous bone flaps cryopreserved with Dimethylsulphoxide: does tissue processing matter. World Neurosurgery, vol. 149 (may.), pp. e582?e591, que se ha publicado de fo…
How to preserve and handle fish liver samples to conserve RNA integrity
2019
As transcriptomic studies are becoming more and more common, it is important to ensure that the RNA used in the analyses is of good quality. The RNA integrity may be compromised by storage temperature or freeze-thaw cycles, but these have not been well studied in poikilothermic fishes. This work studied the effects of tissue storage time and temperature, and freeze-thaw cycles of tissue and extracted RNA on RNA integrity in brown trout (Salmo trutta L.) liver. The storage time and temperature had an effect on RNA integrity, but RNA suitable for quantitative reverse transcription PCR (RT-qPCR) (RIN > 7) was still obtained from samples preserved at − 20 °C for 6 months. Freeze-thaw cycles of …
Origin and ploidy of multipronuclear zygotes
2000
Recently, several authors have proposed strategies for correction of triploidy based on the removal of the extra pronucleus at the zygote stage. In the present bioassay, the following were analysed: (1) the different factors that can induce the formation of multipronuclear zygotes in mammals; (2) the different morphological patterns established according to the number of pronuclei and polar bodies that can be observed at the zygote stage and used to distinguish the origin of multipronuclear zygotes; and (3) the pattern of chromosomal segregation during the first mitotic division and ploidy status of the resulting preim-plantation embryos. Such an analysis shows that the morphological crite…