366 research outputs found

    Laryngeal transplantation in minipigs: vascular, myologic and functional outcomes

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    There is no effective way of replacing all the functions of the larynx in those requiring laryngectomy. Regenerative medicine offers promise, but cannot presently deliver implants with functioning neuromuscular units. A single well-documented laryngeal transplant in man was a qualified success, but more information is required before clinical trials may be proposed. We studied the early response of the larynx to laryngeal transplantation between 17 pairs of NIH minipigs full matched at the MHC2 locus. Following iterative technical improvements, pigs had good swallowing and a patent airway at 1 week. No significant changes in mucosal blood flux were observed compared with pre-operative measurements. Changes in muscle morphology and fibre phenotype were observed in transplant muscles retrieved after 7 days: the levels of fast and slow myosin heavy chain (MyHC) protein were reduced and embryonic MyHC was up regulated consistent with denervation induced atrophy. At 1 week laryngeal transplantation can result in good swallowing, and is not associated with clinical evidence of ischemia-reperfusion injury in MHC-matched pigs

    ZD6474 – clinical experience to date

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    ZD6474 selectively targets two key pathways in tumour growth by inhibiting vascular endothelial growth factor (VEGF)-dependent tumour angiogenesis and epidermal growth factor (EGF)-dependent tumour cell proliferation and survival. Phase I clinical evaluation has shown ZD6474 to be generally well tolerated, with a pharmacokinetic profile appropriate for once-daily oral dosing. Phase II evaluation of ZD6474 at doses of 100−300 mg is ongoing in a range of patient types in single and combination regimens. These include three randomised studies of patients with non-small-cell lung cancer. In one of these trials, the efficacy of ZD6474 monotherapy is being compared with that of the EGF receptor tyrosine kinase inhibitor gefitinib (Iressa™) in previously treated patients. In the other two trials, the efficacy of ZD6474 in combination with certain standard chemotherapy regimens is being compared with that of standard chemotherapy alone: one with carboplatin and paclitaxel in previously untreated patients, and the second with docetaxel in patients who progressed after platinum-containing therapy. The advent of novel molecular-targeted agents such as ZD6474 has necessitated a re-evaluation of conventional cancer study design in order to optimise appraisal of this new generation of anticancer agents. The specific considerations of the ZD6474 clinical programme are discussed

    Pathologic characteristics of resected squamous cell carcinoma of the trachea: prognostic factors based on an analysis of 59 cases

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    While squamous cell carcinoma (SCC) is the most common tracheal malignancy, few reports describe the pathologic considerations that may guide intraoperative decisions and prognostic assessment. We reviewed 59 tracheal SCC treated between 1985 and 2008 by segmental resection of the trachea, including resection of the carina in 24% and inferior larynx in 14%. We classified these tumors by grading histologic differentiation and microscopic features used in SCC of other sites. Of 59 tumors, 24% (14 of 59) were well differentiated, 49% (29 of 59) were moderately differentiated, and 27% (16 of 59) were poorly differentiated. Unfavorable prognostic factors were tumor extension into the thyroid gland (all of five so-afflicted patients died of tumor progression within 3 years) and lymphatic invasion (mean survival 4.6 versus 7.6 years). Keratinization, dyskeratosis, acantholysis, necrosis, and tumor thickness did not predict prognosis. As surgical resection is the only curative treatment; the surgeon should establish clean lines of resection using, as appropriate, intraoperative frozen section. The pathologist can provide additional important prognostic information, including tumor differentiation and extent, invasion of surgical margins, and extension into the thyroid

    The use of mathematical modelling for improving the tissue engineering of organs and stem cell therapy

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    © 2016 Bentham Science Publishers.Regenerative medicine is a multidisciplinary field where continued progress relies on the incorporation of a diverse set of technologies from a wide range of disciplines within medicine, science and engineering. This review describes how one such technique, mathematical modelling, can be utilised to improve the tissue engineering of organs and stem cell therapy. Several case studies, taken from research carried out by our group, ACTREM, demonstrate the utility of mechanistic mathematical models to help aid the design and optimisation of protocols in regenerative medicine

    Lung sealant and morbidity after pleural decortication: a prospective randomized, blinded study

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    <p>Abstract</p> <p>Objectives</p> <p>Prolonged postoperative air leaks (AL) are a major cause of morbidity. Aim of this work was evaluating use of a Lung Sealant System (Pleurasealâ„¢, Covidien, Mansfield, MA, U.S.A.) in pleural decortications for empyema thoracis.</p> <p>Methods</p> <p>From January 2008 to December 2008, 46 consecutive patients received pleural decortications for empyema thoracis. Post-procedural and malignancy-related empyemas were excluded. After hydro-pneumatic test and surgical correction of AL (until satisfaction), patients were assigned (23 per group) to Control or Sealant group. Control group underwent no additional interventions. In Sealant group, lung sealant was applied over AL areas. Following variables were measured daily: patients with AL; time to chest drainage (CD) removal; CD drainage volume at removal, postoperative length of hospital stay, postoperative C-reactive protein (CRP), and leukocyte counts. Personnel recording parameters were blinded to intervention. Two-tailed t-tests (normally distributed data) or Mann - Whitney U-test (not-normally distributed data) were used for evaluating significance of differences between group means or medians. Significance of any proportional differences in attributes were evaluated using Fisher's Exact Test. Statistical analysis was carried out using R-software (version 2.8.1).</p> <p>Results</p> <p>Groups were similar regarding demographic and baseline characteristics. No patients were withdrawn from study; no adverse effects were recorded. There were no significative differences on CRP and leukocyte levels between two groups. Compared with the Control group, in Sealant group significantly fewer patients had AL (30 versus 78%, <it>p = 0.012</it>), and drains were inserted for a shorter time (medians, 3 versus 5 days, <it>p = 0.05</it>). Postoperative hospitalization time was shorter in Sealant group than in control group, but difference was not significant (0.7 days, <it>p = 0.121</it>).</p> <p>Conclusions</p> <p>Pleurasealâ„¢ Lung Sealant System significantly reduces AL following pleural decortications for empyema and, despite of not-increased infectious indexes, is suitable for routinely use, even in procedures with contaminated pleura.</p

    Characterization of Stem-Like Cells in Mucoepidermoid Tracheal Paediatric Tumor

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    Stem cells contribute to regeneration of tissues and organs. Cells with stem cell-like properties have been identified in tumors from a variety of origins, but to our knowledge there are yet no reports on tumor-related stem cells in the human upper respiratory tract. In the present study, we show that a tracheal mucoepidermoid tumor biopsy obtained from a 6 year-old patient contained a subpopulation of cells with morphology, clonogenicity and surface markers that overlapped with bone marrow mesenchymal stromal cells (BM-MSCs). These cells, designated as MEi (mesenchymal stem cell-like mucoepidermoid tumor) cells, could be differentiated towards mesenchymal lineages both with and without induction, and formed spheroids in vitro. The MEi cells shared several multipotent characteristics with BM-MSCs. However, they displayed differences to BM-MSCs in growth kinectics and gene expression profiles relating to cancer pathways and tube development. Despite this, the MEi cells did not possess in vivo tumor-initiating capacity, as proven by the absence of growth in situ after localized injection in immunocompromised mice. Our results provide an initial characterization of benign tracheal cancer-derived niche cells. We believe that this report could be of importance to further understand tracheal cancer initiation and progression as well as therapeutic development

    Rapamycin-mediated mouse lifespan extension: Late-life dosage regimes with sex-specific effects.

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    To see if variations in timing of rapamycin (Rapa), administered to middle aged mice starting at 20 months, would lead to different survival outcomes, we compared three dosing regimens. Initiation of Rapa at 42 ppm increased survival significantly in both male and female mice. Exposure to Rapa for a 3-month period led to significant longevity benefit in males only. Protocols in which each month of Rapa treatment was followed by a month without Rapa exposure were also effective in both sexes, though this approach was less effective than continuous exposure in female mice. Interpretation of these results is made more complicated by unanticipated variation in patterns of weight gain, prior to the initiation of the Rapa treatment, presumably due to the use of drug-free food from two different suppliers. The experimental design included tests of four other drugs, minocycline, β-guanidinopropionic acid, MitoQ, and 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), but none of these led to a change in survival in either sex

    Rapamycin-mediated mouse lifespan extension: Late-life dosage regimes with sex-specific effects.

    Get PDF
    To see if variations in timing of rapamycin (Rapa), administered to middle aged mice starting at 20 months, would lead to different survival outcomes, we compared three dosing regimens. Initiation of Rapa at 42 ppm increased survival significantly in both male and female mice. Exposure to Rapa for a 3-month period led to significant longevity benefit in males only. Protocols in which each month of Rapa treatment was followed by a month without Rapa exposure were also effective in both sexes, though this approach was less effective than continuous exposure in female mice. Interpretation of these results is made more complicated by unanticipated variation in patterns of weight gain, prior to the initiation of the Rapa treatment, presumably due to the use of drug-free food from two different suppliers. The experimental design included tests of four other drugs, minocycline, β-guanidinopropionic acid, MitoQ, and 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), but none of these led to a change in survival in either sex
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