a b s t r a c tA variety of Good Manufacturing Practice (GMP) compliant processes have been reported for production of non-replicating adenovirus vectors, but important challenges remain. Most clinical development of adenovirus vectors now uses simian adenoviruses or rare human serotypes, whereas reported manufacturing processes mainly use serotypes such as AdHu5 which are of questionable relevance for clinical vaccine development. Many clinically relevant vaccine transgenes interfere with adenovirus replication, whereas most reported process development uses selected antigens or even model transgenes such as fluorescent proteins which cause little such interference. Processes are typically developed for a single adenovirus serotype -transgene combination, requiring extensive further optimization for each new vaccine.There is a need for rapid production platforms for small GMP batches of non-replicating adenovirus vectors for early-phase vaccine trials, particularly in preparation for response to emerging pathogen outbreaks. Such platforms must be robust to variation in the transgene, and ideally also capable of producing adenoviruses of more than one serotype. It is also highly desirable for such processes to be readily implemented in new facilities using commercially available single-use materials, avoiding the need for development of bespoke tools or cleaning validation, and for them to be readily scalable for later-stage studies.Here we report the development of such a process, using single-use stirred-tank bioreactors, a transgene-repressing HEK293 cell -promoter combination, and fully single-use filtration and ion exchange components. We demonstrate applicability of the process to candidate vaccines against rabies, malaria and Rift Valley fever, each based on a different adenovirus serotype. We compare performance of a range of commercially available ion exchange media, including what we believe to be the first published use of a novel media for adenovirus purification (NatriFlo Ò HD-Q, Merck). We demonstrate the need for minimal process individualization for each vaccine, and that the product fulfils regulatory quality expectations. Cell-specific yields are at the upper end of those previously reported in the literature, and volumetric yields are in the range 1 Â 10 13 -5 Â 10 13 purified virus particles per litre of culture, such that a 2-4 L process is comfortably adequate to produce vaccine for early-phase trials. The process is readily transferable to any GMP facility with the capability for mammalian cell culture and aseptic filling of sterile products.
BackgroundSignificant gaps currently exist in the Canadian internal medicine point-of-care ultrasound (POCUS) curriculum. From a learner’s perspective, it remains unknown what key POCUS skills should be prioritized. This needs assessment study seeks to establish educational priorities for POCUS for internal medicine residents at five Canadian residency training programs.MethodsAll internal medicine trainees [postgraduate year (PGY) 1–5] from five internal medicine residency training programs in Canada (n = 598) were invited to complete an online survey on 15 diagnostic POCUS applications, 9 bedside procedures, and 18 POCUS knowledge items. For POCUS applications and procedures, participants were asked how applicable they are to patient care in internal medicine and the participants’ reported skills in those domains. Self-reported knowledge and skills were rated on a 5-point Likert scale, where 1 = very poor and 5 = very good. Applicability was rated, where 1 = not at all applicable and 5 = very applicable.ResultsA total of 253 of 598 residents (42%) participated in our study. Data from one centre (n = 15) was removed because of low response rate (15%) and significant baseline differences between those trainees and the remaining participants. Of the remaining analyzable data from four training programs (n = 238), participants reported highest applicability to internal medicine for the following applications and procedures: identifying ascites/free fluid [mean applicability score of 4.9 ± standard deviation (SD) 0.4]; gross left ventricular function (mean 4.8 ± SD 0.5) and pericardial effusion (mean 4.7 ± SD 0.5); thoracentesis (mean score 4.9 ± SD 0.3), central line insertion (mean 4.9 ± SD 0.3), and paracentesis (mean 4.9 ± SD 0.3), respectively. Overall reported knowledge/skills was low, with skill gaps being the highest for identifying deep vein thrombosis (mean gap 2.7 ± SD 1.1), right ventricular strain (mean 2.7 ± SD 1.1), and gross left ventricular function (mean 2.7 ± SD 1.0).ConclusionsMany POCUS applications and procedures were felt to be applicable to the practice of internal medicine. Significant skill gaps exist in the four Canadian training programs included in the study. POCUS curriculum development efforts should target training based on these perceived skill gaps.Electronic supplementary materialThe online version of this article (10.1186/s12909-018-1326-8) contains supplementary material, which is available to authorized users.
Leptin injections evoke weight loss by causing a reduction in food consumption and an increase in energy expenditure. Also, the administration of leptin lowers blood glucose levels in some rodent models of diabetes and in humans with lipodystrophy. We explored the therapeutic potential of delivering leptin to obese, diabetic ob/ob mice and to mice fed on a high-fat diet (HFD), by transplanting gut-derived cells engineered to produce leptin, under the regulation of an inducing agent, mifepristone. These cells expressed and released leptin in a mifepristone dose-dependent and time-dependent manner. The engineered cells were either transplanted into the mice under the kidney capsule or were encapsulated in alginate and injected into the intraperitoneal cavity, while mifepristone was delivered by implanting 14-day release pellets. In ob/ob mice, leptin delivery by this method caused a significant reduction in food intake and profound weight loss, which was controllable by adjusting the dose of mifepristone. These transplants also achieved rapid and persistent amelioration of diabetes. However, mice fed on a HFD were resistant to the leptin therapy. These results indicate that gut cells can be modified to express leptin in an inducible manner and that the transplantation of these cells has a therapeutic effect in leptin-deficient mice, but not in mice fed on a HFD.
Background Point-of-care ultrasound (POCUS) is a growing part of internal medicine training programs. Dedicated POCUS rotations are emerging as a particularly effective tool in POCUS training, allowing for longitudinal learning and emphasizing both psychomotor skills and the nuances of clinical integration. In this descriptive paper, we set out to review the state of POCUS rotations in Canadian Internal Medicine training programs. Results We identify five programs currently offering a POCUS rotation. These rotations are offered over two to thirteen blocks each year, run over one to four weeks and support one to four learners. Across all programs, these rotations are set up as a consultative service that offers POCUS consultation to general internal medicine inpatients, with some extension of scope to the hospitalist service or surgical subspecialties. The funding model for the preceptors of these rotations is predominantly fee-for-service using consultation codes, in addition to concomitant clinical work to supplement income. All but one program has access to hospital-based archiving of POCUS exams. Preceptors dedicate ten to fifty hours to the rotation each week and ensure that all trainee exams are reviewed and documented in the patient’s medical records in the form of a consultation note. Two of the five programs also support a POCUS fellowship. Only two out of five programs have established learner policies. All programs rely on In-Training Evaluation Reports to provide trainee feedback on their performance during the rotation. Conclusions We describe the different elements of the POCUS rotations currently offered in Canadian Internal Medicine training programs. We share some lessons learned around the elements necessary for a sustainable rotation that meets high educational standards. We also identify areas for future growth, which include the expansion of learner policies, as well as the evolution of trainee assessment in the era of competency-based medical education. Our results will help educators that are endeavoring setting up POCUS rotations achieve success.
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