882 resultados para Tissue and Organ Harvesting


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Throughout history, developments in medicine have aimed to improve patient quality of life, and reduce the trauma associated with surgical treatment. Surgical access to internal organs and bodily structures has been traditionally via large incisions. Endoscopic surgery presents a technique for surgical access via small (1 Omm) incisions by utilising a scope and camera for visualisation of the operative site. Endoscopy presents enormous benefits for patients in terms of lower post operative discomfort, and reduced recovery and hospitalisation time. Since the first gall bladder extraction operation was performed in France in 1987, endoscopic surgery has been embraced by the international medical community. With the adoption of the new technique, new problems never previously encountered in open surgery, were revealed. One such problem is that the removal of large tissue specimens and organs is restricted by the small incision size. Instruments have been developed to address this problem however none of the devices provide a totally satisfactory solution. They have a number of critical weaknesses: -The size of the access incision has to be enlarged, thereby compromising the entire endoscopic approach to surgery. - The physical quality of the specimen extracted is very poor and is not suitable to conduct the necessary post operative pathological examinations. -The safety of both the patient and the physician is jeopardised. The problem of tissue and organ extraction at endoscopy is investigated and addressed. In addition to background information covering endoscopic surgery, this thesis describes the entire approach to the design problem, and the steps taken before arriving at the final solution. This thesis contributes to the body of knowledge associated with the development of endoscopic surgical instruments. A new product capable of extracting large tissue specimens and organs in endoscopy is the final outcome of the research.

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The aim of this study was to evaluate the effect of delaying ovulation subsequent to superstimulation of follicular growth in beef cows (Bos indicus) on embryo recovery rates and the capacity of embryos to establish pregnancies. Ovulation was delayed by three treatments using either progesterone (CIDR-B®) or a GnRH agonist (deslorelin). Multiparous Nelore cows (n = 24) received three of four superstimulation treatments in an incomplete block design (n = 18 per group). Cows in Groups CTRL, P48 and P60 were treated with a CIDR-B device plus estradiol benzoate (EB, 4 mg, i.m.) on Day-5, while cows in Group D60 were implanted with deslorelin on Day-7. Cows were superstimulated with FSH (Folltropin-V® 200 mg), from Day 0 to 3, using twice daily injections in decreasing amounts. All cows were treated with a luteolytic dose of prostaglandin on Day 2 (08:00 h). CIDR-B devices were removed as follows: Group CTRL, Day 2 (20:00 h); Group P48, Day 4 (08:00 h); Group P60, Day 4 (20:00 h). Cows in Group CTRL were inseminated at 10, 20 and 30 h after first detected estrus. Ovulation was induced for cows in Group P48 (Day 4, 08:00 h) and Groups P60 and D60 (Day 4, 20:00 h) by injection of LH (Lutropin®, 25 mg, i.m.), and these cows were inseminated 10 and 20 h after treatment with LH. Embryos were recovered on Days 11 or 12, graded and transferred to synchronized recipients. Pregnancies were determined by ultrasonography around Day 100. Data were analyzed by mixed procedure, Kruskal-Wallis and Chi-square tests. The number of ova/embryos, transferable embryos (mean ± S.E.M.) and pregnancy rates (%) were as follows, respectively: Group CTRL (10.8 ± 1.8, 6.1 ± 1.3, 51.5), P48 (12.6 ± 1.9, 7.1 ± 1.0, 52.3), P60 (10.5 ± 1.6, 5.7 ± 1.3, 40.0) and D60 (10.3 ± 1.7, 5.0 ± 1.2, 50.0). There were no significant differences among the groups (P > 0.05). It was concluded that fixed time AI in association with induced ovulation did not influence embryo recovery. Furthermore, pregnancy rates in embryos recovered from cows with delayed ovulation were similar to those in embryos obtained from cows treated with a conventional superstimulation protocol. © 2002 Elsevier B.V. All rights reserved.

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Burn injury is associated with disabling scar formation which impacts on many aspects of the patient's life. Previously we have shown that the fetus heals a deep dermal burn in a scarless fashion. Amniotic membrane (AM) is the outermost fetal tisue and has beeen used as a dressing in thermal injuries, though there is little data to support this use. To assess the efficacy of AM in scar minimisation after deep dermal burn wound, we conducted a randomised controlled study in the 1-month lamb. Lambs were delivered by caesarian section and the amniotic membranes stored after which lambs were returned to their mothers post-operatively. At 1 month, a standardised deep dermal burn was created under general anaesthesia on both flanks of the lamb. One flank was covered with unmatched AM, the other with paraffin gauze. Animals were sequentially euthanased from Day 3-60 after injury and tissue analysed for histopathology and immunohistochemically for alpha-smooth muscle actin (alphaSMA) content. AM resulted in reduced scar tissue as assessed histopathologically and reduced alphaSMA content. This study provides the first laboratory evidence that AM may reduce scar formation after burn injury.

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Maxillomandibular reconstructions are traditionally performed by means of autogenous bone grafts collected from intraoral donor areas and extraoral donor areas such as clavicle, iliac bone, rib, and tibia. The calvarial bone has been studied as an alternative donor area, with a low incidence of complications and minimal postoperative morbidity. Complications such as dural lacerations associated with cerebrospinal fluid leakage and extradural and subdural bleeding were minimized due to the use of surgical trepan, allowing the diploic layer delimitation before the osteotomy, preserving the internal calvarial cortical. The purpose of this article is to suggest a new technique for the obtainment of calvarial bone grafts with surgical trepan.

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Campylobacter jejuni is an important food-borne pathogen. However, relatively little is understood regarding its pathogenesis, and research is hampered by the lack of a suitable model. Recently, a number of groups have developed assays to study the pathogenic mechanisms of C. jejuni using cell culture models. Here, we report the development of an ex vivo organ culture model, allowing for the maintenance of intestinal mucosal tissue, to permit more complex host-bacterium interactions to be studied. Ex vivo organ culture highlights the propensity for C. jejuni to adhere to mucosal tissue via the flagellum, either as discrete colonies or as multicellular units.

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TERMINAL EAR1-like (TEL) genes encode putative RNA-binding proteins only found in land plants. Previous studies suggested that they may regulate tissue and organ initiation in Poaceae. Two TEL genes were identified in both Populus trichocarpa and the hybrid aspen Populus tremula × P. alba, named, respectively, PoptrTEL1-2 and PtaTEL1-2. The analysis of the organisation around the PoptrTEL genes in the P. trichocarpa genome and the estimation of the synonymous substitution rate for PtaTEL1-2 genes indicate that the paralogous link between these two Populus TEL genes probably results from the Salicoid large-scale gene-duplication event. Phylogenetic analyses confirmed their orthology link with the other TEL genes. The expression pattern of both PtaTEL genes appeared to be restricted to the mother cells of the plant body: leaf founder cells, leaf primordia, axillary buds and root differentiating tissues, as well as to mother cells of vascular tissues. Most interestingly, PtaTEL1-2 transcripts were found in differentiating cells of secondary xylem and phloem, but probably not in the cambium itself. Taken together, these results indicate specific expression of the TEL genes in differentiating cells controlling tissue and organ development in Populus (and other Angiosperm species).

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Biomarkers are conventionally defined as "biological molecules that represent health and disease states." They typically are measured in readily available body fluids (blood or urine), lie outside the causal pathway, are able to detect subclinical disease, and are used to monitor clinical and subclinical disease burden and response to treatments. Biomarkers can be "direct" endpoints of the disease itself, or "indirect" or surrogate endpoints. New technologies (such as metabolomics, proteomics, genomics) bring a wealth of opportunity to develop new biomarkers. Other new technologies enable the development of nonmolecular, functional, or biophysical tissue-based biomarkers. Diabetes mellitus is a complex disease affecting almost every tissue and organ system, with metabolic ramifications extending far beyond impaired glucose metabolism. Biomarkers may reflect the presence and severity of hyperglycemia (ie, diabetes itself) or the presence and severity of the vascular complications of diabetes. Illustrative examples are considered in this brief review. In blood, hemoglobin A1c (HbA1c) may be considered as a biomarker for the presence and severity of hyperglycemia, implying diabetes or prediabetes, or, over time, as a "biomarker for a risk factor," ie, hyperglycemia as a risk factor for diabetic retinopathy, nephropathy, and other vascular complications of diabetes. In tissues, glycation and oxidative stress resulting from hyperglycemia and dyslipidemia lead to widespread modification of biomolecules by advanced glycation end products (AGEs). Some of these altered species may serve as biomarkers, whereas others may lie in the causal pathway for vascular damage. New noninvasive technologies can detect tissue damage mediated by AGE formation: these include indirect measures such as pulse wave analysis (a marker of vascular dysfunction) and more direct markers such as skin autofluorescence (a marker of long-term accumulation of AGEs). In the future, we can be optimistic that new blood and tissue-based biomarkers will enable the detection, prevention, and treatment of diabetes and its complications long before overt disease develops.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Introduction Several recent studies have shown that a positive fluid balance in critical illness is associated with worse outcome. We tested the effects of moderate vs. high-volume resuscitation strategies on mortality, systemic and regional blood flows, mitochondrial respiration, and organ function in two experimental sepsis models. Methods 48 pigs were randomized to continuous endotoxin infusion, fecal peritonitis, and a control group (n = 16 each), and each group further to two different basal rates of volume supply for 24 hours [moderate-volume (10 ml/kg/h, Ringer's lactate, n = 8); high-volume (15 + 5 ml/kg/h, Ringer's lactate and hydroxyethyl starch (HES), n = 8)], both supplemented by additional volume boli, as guided by urinary output, filling pressures, and responses in stroke volume. Systemic and regional hemodynamics were measured and tissue specimens taken for mitochondrial function assessment and histological analysis. Results Mortality in high-volume groups was 87% (peritonitis), 75% (endotoxemia), and 13% (controls). In moderate-volume groups mortality was 50% (peritonitis), 13% (endotoxemia) and 0% (controls). Both septic groups became hyperdynamic. While neither sepsis nor volume resuscitation strategy was associated with altered hepatic or muscle mitochondrial complex I- and II-dependent respiration, non-survivors had lower hepatic complex II-dependent respiratory control ratios (2.6 +/- 0.7, vs. 3.3 +/- 0.9 in survivors; P = 0.01). Histology revealed moderate damage in all organs, colloid plaques in lung tissue of high-volume groups, and severe kidney damage in endotoxin high-volume animals. Conclusions High-volume resuscitation including HES in experimental peritonitis and endotoxemia increased mortality despite better initial hemodynamic stability. This suggests that the strategy of early fluid management influences outcome in sepsis. The high mortality was not associated with reduced mitochondrial complex I- or II-dependent muscle and hepatic respiration.

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Transplantation is one of the most beautiful achievements for humanity in the last century and became the last hope to many patients. As other beautiful achievements, it has been used by criminals. The future of transplantation will be focused on tissue and cells transplantation. Trafficking of human beings to organ removal and trafficking of human organs are an early stage of trafficking on tissues and cells comparable with slaves trafficking in the 17th and 18th century. As 400 years ago, the motive for the crime is development, economy and profit. Transplant surgery is the modern “cotton gin” to this new commerce. Poverty exploitation, unprotected people, are always the victims. Even so, there are some differences since then. The paying buyers are the patients themselves and the “cotton” transplanted is not so harmless. Unsafe tissues and cells inappropriately collected and allocated can be so dangerous to the recipient and his family, that the dreamed transplant/implant becomes a nightmare. Beyond the trafficking crime, there is a most dangerous associated crime that is the crime of spreading dangerous infectious diseases.

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The therapeutic, social and economic benefits of organ transplantation are irrefutable; however, organ shortages contribute to avoidable patient deaths and burgeoning health care costs. This problem can be addressed by increasing family consent to deceased organ donation. There are high levels of community support for deceased organ donation in Australia and yet, almost fifty percent of families decline the request to donate. Increasing the number of families who agree to deceased organ donation is key to increasing national and international transplantation rates. The purpose of this study was to identify the major factors that influence a family to agree or decline deceased organ donation during the process of decision-making. The aims of the study were three-fold: to identify the key stages and the major influencers’ in the decisionmaking process; to determine if hope, deep hope and trust played a role in the decision, and to explore families’ perceptions of their decision-making experience. The study utilised an exploratory case study approach to examine the family decisionmaking process of deceased organ donation. Following ethics approval, recruitment was conducted utilising a qualitative purposive snowball strategy across Australia. A pilot study was conducted to test the study procedures prior to the main data collection, and 22 participants who had been involved in a deceased organ donation decision from nine families were interviewed. In five deaths family members had agreed to organ donation, and in four deaths the family declined. A theoretical framework based on the Precaution Adoption Process Model of decision-making was applied to propose trust, hope and deep hope underpin family organ donation decisions. Thematic analysis was conducted and three key themes comprising ‘In the fog drowning’, ‘Harvesting humanity’, and ‘It’s all up to Mum’ were revealed. The study found women, and in particular mothers, played a significant role in organ donation decision-making, and that the decision-making is bounded by family needs of trust, hope and deep hope across the continuum of time. It also found families who had their trust, hope and deep hope needs met expressed satisfaction about their decision-making experience and agreed to organ donation. Some families perceived that organ donation was a sacrifice that was too great to endure, even if the deceased had previously indicated intent to donate, and therefore declined donation. This study found that families’ ideas of a peaceful death and organ donation are not mutually exclusive. It concludes that when decision-makers’ trust and deep hope needs are met they are more willing to agree to donation. This study recommends that the idea of a ‘right’ to a peaceful death should be aligned with deceased organ donation practices and normalised.

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Callus was initiated in three different ‘‘esculenta’’ taro cultivars by culturing corm slices in the dark on half-strength MS medium supplemented with 2.0 mg/l 2,4- dichlorophenoxyacetic acid (2,4-D) for 20 days followed by subculture of all corm slices to half-strength MS medium containing 1.0 mg/l thidiazuron (TDZ). Depending on the cultivar, 20–30% of corm slices produced compact, yellow, nodular callus on media containing TDZ. Histological studies revealed the presence of typical embryogenic cells which were small, isodiametric with dense cytoplasms. Somatic embryos formed when callus was transferred to hormone-free medium and *72% of the embryos germinated into plantlets on this medium. Simultaneous formation of roots and shoots during germination, and the presence of shoot and root poles revealed by histology, confirmed that these structures were true somatic embryos. Plants derived from somatic embryos appeared phenotypically normal following 2 months growth in a glasshouse. This method is a significant advance on those previously reported for the esculenta cultivars of taro due to its efficiency and reproducibility.

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Embryogenic callus was initiated by culturing in vitro taro corm slices on agar-solidified half-strength MS medium containing 2.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) for 20 days followed by transfer to 1.0 mg/L thidiazuron (TDZ). Callus was subsequently proliferated on solid medium containing 1.0 mg/L TDZ, 0.5 mg/L 2,4- D and 800 mg/L glutamine before transfer to liquid medium containing the same components but with reduced glutamine (100 mg/L). After 3 months in liquid culture on an orbital shaker, cytoplasmically dense cell aggregates began to form. Somatic embryogenesis was induced by plating suspension cells onto solid media containing reduced levels of hormones (0.1 mg/L TDZ, 0.05 mg/L 2,4-D), high concentrations of sucrose (40–50 g/L) and biotin (1.0 mg/L). Embryo maturation and germination was then induced on media containing 0.05 mg/L benzyladenine (BA) and 0.1 mg/L indole-3-acetic acid (IAA). Histological studies of the developing embryos revealed the presence of typical shoot and root poles suggesting that these structures were true somatic embryos. The rate of somatic embryos formation was 500–3,000 per mL settledcell volume while approximately 60% of the embryos regenerated into plants.