Stop paying through the nose: student and trainee medical conferences offer better value for money than professional alternatives.

BACKGROUND: Scientific conferences in the UK are attended by practising doctors and medical students for sharing research, networking and professional development. Student/trainee conferences are typically cheaper than professional conferences, but as they are not acknowledged in national scoring systems for medical and surgical training applications, they may have worse attendance than otherwise possible. We questioned whether student/trainee conferences are of a similar scientific quality to professional conferences, while being considerably cheaper. METHODS: In this cross-sectional database review, 162 conferences were identified through a systematic search of two conference databases by three independent researchers. χ2 tests were used to compare scientific quality between student/trainee and professional conferences and the likelihood of offering different types of discounts. Independent t-tests were employed to determine cost differences between the two categories of conferences. RESULTS: Our data revealed that there was no significant difference between student/trainee and professional conferences likelihood of declaring information on their abstract review processes (p=0.105). There was no difference in speaker seniority, determined by the tool the authors developed (p=0.172). Student/trainee conferences were significantly more likely to offer workshops (p<0.0005) and were cheaper than professional conferences (p<0.0005). CONCLUSION: Our results show that student/trainee conferences offer a similar level of scientific quality to professional medical conferences in the UK at a fraction of the cost, which should be reflected within the national scoring systems.

CD28 null CD4 T-cell expansions in autoimmune disease suggest a link with cytomegalovirus infection.

Immunosenescence is thought to contribute to the increase of autoimmune diseases in older people. Immunosenescence is often associated with the presence of an expanded population of CD4 T cells lacking expression of CD28 (CD28 null). These highly cytotoxic CD4 T cells were isolated from disease-affected tissues in patients with rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, or other chronic inflammatory diseases and their numbers appeared to be linked to disease severity. However, we recently demonstrated that the common herpes virus, cytomegalovirus (CMV), not ageing, is the major driver of this subset of cytotoxic T cells. In this review, we discuss how CMV might potentiate and exacerbate autoimmune disease through the expansion of CD28 null CD4 T cells.

Buffers Strongly Modulate Fibrin Self-Assembly into Fibrous Networks.

Fibrin is a plasma protein with a central role in blood clotting and wound repair. Upon vascular injury, fibrin forms resilient fibrillar networks (clots) via a multistep self-assembly process, from monomers, to double-stranded protofibrils, to a branched network of thick fibers. In vitro, fibrin self-assembly is sensitive to physicochemical conditions like the solution pH and ionic strength, which tune the strength of the noncovalent driving forces. Here we report a surprising finding that the buffer-which is necessary to control the pH and is typically considered to be inert-also significantly influences fibrin self-assembly. We show by confocal microscopy and quantitative light scattering that various common buffering agents have no effect on the initial assembly of fibrin monomers into protofibrils but strongly hamper the subsequent lateral association of protofibrils into thicker fibers. We further find that the structural changes are independent of the molecular structure of the buffering agents as well as of the activation mechanism and even occur in fibrin networks formed from platelet-poor plasma. This buffer-mediated decrease in protofibril bundling results in a marked reduction in the permeability of fibrin networks but only weakly influences the elastic modulus of fibrin networks, providing a useful tuning parameter to independently control the elastic properties and the permeability of fibrin networks. Our work raises the possibility that fibrin assembly in vivo may be regulated by variations in the acute-phase levels of bicarbonate and phosphate, which act as physiological buffering agents of blood pH. Moreover, our findings add a new example of buffer-induced effects on biomolecular self-assembly to recent findings for a range of proteins and lipids.

A constitutive model for developing blood clots with various compositions and their nonlinear viscoelastic behavior.

The mechanical properties determine to a large extent the functioning of a blood clot. These properties depend on the composition of the clot and have been related to many diseases. However, the various involved components and their complex interactions make it difficult at this stage to fully understand and predict properties as a function of the components. Therefore, in this study, a constitutive model is developed that describes the viscoelastic behavior of blood clots with various compositions. Hereto, clots are formed from whole blood, platelet-rich plasma and platelet-poor plasma to study the influence of red blood cells, platelets and fibrin, respectively. Rheological experiments are performed to probe the mechanical behavior of the clots during their formation. The nonlinear viscoelastic behavior of the mature clots is characterized using a large amplitude oscillatory shear deformation. The model is based on a generalized Maxwell model that accurately describes the results for the different rheological experiments by making the moduli and viscosities a function of time and the past and current deformation. Using the same model with different parameter values enables a description of clots with different compositions. A sensitivity analysis is applied to study the influence of parameter variations on the model output. The relative simplicity and flexibility make the model suitable for numerical simulations of blood clots and other materials showing similar behavior.

A constitutive model for the time-dependent, nonlinear stress response of fibrin networks.

Blood clot formation is important to prevent blood loss in case of a vascular injury but disastrous when it occludes the vessel. As the mechanical properties of the clot are reported to be related to many diseases, it is important to have a good understanding of their characteristics. In this study, a constitutive model is presented that describes the nonlinear viscoelastic properties of the fibrin network, the main structural component of blood clots. The model is developed using results of experiments in which the fibrin network is subjected to a large amplitude oscillatory shear (LAOS) deformation. The results show three dominating nonlinear features: softening over multiple deformation cycles, strain stiffening and increasing viscous dissipation during a deformation cycle. These features are incorporated in a constitutive model based on the Kelvin-Voigt model. A network state parameter is introduced that takes into account the influence of the deformation history of the network. Furthermore, in the period following the LAOS deformation, the stiffness of the networks increases which is also incorporated in the model. The influence of cross-links created by factor XIII is investigated by comparing fibrin networks that have polymerized for 1 and 2 h. A sensitivity analysis provides insights into the influence of the eight fit parameters. The model developed is able to describe the rich, time-dependent, nonlinear behavior of the fibrin network. The model is relatively simple which makes it suitable for computational simulations of blood clot formation and is general enough to be used for other materials showing similar behavior.

A constitutive model for a maturing fibrin network.

Blood clot formation is crucial to maintain normal physiological conditions but at the same time involved in many diseases. The mechanical properties of the blood clot are important for its functioning but complicated due to the many processes involved. The main structural component of the blood clot is fibrin, a fibrous network that forms within the blood clot, thereby increasing its mechanical rigidity. A constitutive model for the maturing fibrin network is developed that captures the evolving mechanical properties. The model describes the fibrin network as a network of fibers that become thicker in time. Model parameters are related to the structural properties of the network, being the fiber length, bending stiffness, and mass-length ratio. Results are compared with rheometry experiments in which the network maturation is followed in time for various loading frequencies and fibrinogen concentrations. Three parameters are used to capture the mechanical behavior including the mass-length ratio. This parameter agrees with values determined using turbidimetry experiments and is subsequently used to derive the number of protofibrils and fiber radius. The strength of the model is that it describes the mechanical properties of the maturing fibrin network based on it structural quantities. At the same time the model is relatively simple, which makes it suitable for advanced numerical simulations of blood clot formation during flow in blood vessels.

An evaluation of CPD activity of dentists in Wales.

INTRODUCTION: Ongoing professional education is essential for dental professionals to maintain and update their clinical skills and knowledge. There is a current trend towards mandatory Continuing Professional Development (CPD) for dentists within Europe and beyond. Mandatory CPD will ensure high professional standards and enable mobilisation of the dental workforce within Europe. In 2002, the UK General Dental Council (GDC) implemented a system of mandatory CPD for dentists practicing in the UK. The Wales Deanery is situated in the School of Postgraduate Medical and Dental Education, Cardiff University. It provides verifiable CPD courses for dentists and dental care professionals (DCPs) currently practicing in Wales and has recorded professionals' attendance on these courses since 2001. The project aimed to investigate the CPD activity of dentists in Wales, using these data. METHODS: The Wales Deanery database holds data on the CPD courses undertaken by 1178 dentists working in Wales since 2001. A number of hypotheses were investigated using a variety of statistical methods. RESULTS: Dentists were undertaking significantly fewer hours of CPD in Mid and West Wales compared to the North and South of the principality. Sole practitioners were found to engage in less CPD than those in group practices, but these differences did not reach statistical significance. Dentists who employed a hygienist or therapist completed more hours of CPD than those who didn't employ either. There were no gender differences in engagement in CPD. CPD participation was consistently and significantly higher in mid and late career than in early career. CONCLUSIONS: This study provides a greater understanding of the CPD habits of the dental workforce in Wales. Practice staffing levels, location of practice and time since graduation were found to have the greatest impact on engagement in CPD activity. These findings will be used by the Deanery to inform future education provision for dental professionals in Wales.

The effect of cigarette smoking and native bone height on dental implants placed immediately in sinuses grafted by hydraulic condensation.

The purpose of this study was to determine the effect of cigarette smoking and residual native bone height on the survival of dental implants placed immediately in grafted sinuses. In this retrospective study, 334 subject records were screened, and 75 subjects (155 implants) were included. Data collection based on treatment notes and radiographs included age, sex, smoking status, sinus floor bone height, dental implant information, and implant survival. The survival rates of implants for nonsmokers and smokers at stage-two surgery were 93% and 84%, respectively. After 12 months of functional loading, the survival rates of implants for nonsmokers and smokers were 87% (81 of 93) and 79% (49 of 62), respectively (P < .000). Analysis revealed that the effect of smoking on implant survival is significant when the preoperative bone height is less than 4 mm, with an 82.4% implant survival rate in nonsmokers compared to 60% in smokers (P < .05). Smoking should be considered as a high risk factor when implants are placed immediately in grafted sinuses, particularly in areas of limited bone height.

Continuing dental education in radiation protection: knowledge retention following a postgraduate course.

OBJECTIVE: To evaluate medium-term knowledge retention of dental personnel following attendance at a postgraduate course in radiation protection. SUBJECTS AND METHODS: Knowledge was measured using identical pre- and post-course validated single best-answer multiple-choice instruments, administered immediately before and after training and at follow-up at 6 or 12 months. These comprise 16 questions each with 5 choices. The range of possible scores was from 0 to 16, and scores were scaled to percentages. Participants were predominantly dental practitioners, but a minority consisted of dental care professionals (dental nurses, hygienists and therapists). Of 285 participants, 272 (95.4%) completed both pre- and post-course questionnaires. One hundred and seventeen (43%) of these also completed the follow-up test, but only 109 (40%) individuals could be linked to the original course. RESULTS: Mean (standard deviation) pre-, post-course and follow-up-corrected percentage scores were 39.1 (16.1), 74.6 (16.9) and 58.9 (22.7), respectively. There was attrition in knowledge at follow-up: the average increase in adjusted score after training was 35.5 points, but only 56% of this was retained at follow-up. Paired t-tests confirmed that the mean score at follow-up was firmly intermediate between the pre- and post-course scores. Of the 109 participants, 7 (6%) achieved a satisfactory score pre-training, 82 (75%) immediately post-training and 41 (38%) at follow-up. There were gross differences between the levels of performance achieved for the eight subject areas tested. CONCLUSION: Immediate post-course assessments have indicated that current postgraduate courses in radiation protection are effective. However, a substantial amount of knowledge is lost by 6-12 months following course attendance. To achieve long-term knowledge retention, early or repeated reinforcement may be necessary.

The Winchester falls project: a randomised controlled trial of secondary prevention of falls in older people.

BACKGROUND: the mortality and morbidity of falls in older people is significant, with recurrent fallers being at an increased risk. The most effective way to reduce falls in this group is not clear. OBJECTIVE: to determine the effectiveness of two interventions, one based in primary care and the other in secondary care, at preventing further falls in recurrent fallers. DESIGN: cluster randomised controlled trial. PARTICIPANTS: sixty-five years or over, living in the community, two or more falls in the previous year and not presenting to an emergency department with index fall. SETTING: Mid Hampshire, UK. INTERVENTION: eighteen general practices were randomly allocated to one of three groups. The primary care group was assessed by nurses in the community, using a risk factor review and subsequent targeted referral to other professionals. The secondary care group received a multi-disciplinary assessment in a day hospital followed by identified appropriate interventions. The control group received usual care. Follow-up was for 1 year. RESULTS: five hundred and five participants were recruited. Follow-up was completed in 83% (421/505). The proportion of participants who fell again was significantly lower in the secondary care group (75%, 158/210) compared to the control group [84%, 133/159, adjusted odds ratio (OR) 0.52 (95% CI 0.35-0.79) P = 0.002]. The primary care group showed similar results to the control group [87%, 118/136, adjusted OR 1.17 (95% CI 0.57-2.37) P = 0.673]. CONCLUSION: a structured multi-disciplinary assessment of recurrent fallers significantly reduced the number experiencing further falls, but a community-based nurse-led assessment with targeted referral to other professionals did not.

Reninoma: case report and literature review.

Reninoma is a tumor of the renal juxtaglomerular cell apparatus that causes hypertension and hypokalemia via hypersecretion of renin. We describe a case of reninoma and provide a review of the literature, with a discussion emphasizing the diagnostic evaluation for such patients. The subject had persistent elevation of both plasma renin activity (PRA) and aldosterone. Imaging studies revealed the presence of a lesion in the renal cortex, which was further identified as a renin-producing lesion via selective venous catheterization following administration of an angiotensin-converting enzyme inhibitor (ACE-I). Following partial nephrectomy, the PRA and plasma aldosterone levels declined rapidly and the blood pressure and potassium supplementation requirements normalized. This case demonstrates the utility of both appropriate imaging studies and selective venous catheterization following provocative administration of an ACE-I for diagnosis.

Who wants to be a surgeon? A study of 300 first year medical students.

BACKGROUND: While medicine in general is becoming more female-dominated, women are still under-represented in surgery. Opinion is divided as to whether this is due to lifestyle considerations, disinterest or perceived discrimination. It is not clear at what stage these careers decisions are made. METHODS: 300 first year medical students at Guy's King's and St Thomas' School of Medicine (GKT) were asked their view on possible career choices at this stage. RESULTS: While men represented only 38% of the student population, they represented over two-thirds of the students wishing to pursue a career in surgery. Women still opt for general practice and paediatrics. CONCLUSION: Surgery is a disproportionately unpopular career choice of the female first-year medical students of GKT compared to the male students. It appears that the choice is freely made and, at this stage at least, does not represent concerns about compatibility with lifestyle.

The effectiveness of dental postgraduate courses--are we doing the right thing?

OBJECTIVE: To evaluate the effectiveness of dental postgraduate one-day courses in radiation protection in Wales. DESIGN: Analysis of dentists' performance pre- and immediately post-course training. SUBJECTS AND METHODS: Two hundred and eighty-five general dental practitioners took part in eight courses. Identical, validated multiple choice questionnaires were completed anonymously at the start and at the end of each course. Fifty (+62.5%) or above was regarded as a satisfactory standard. Two hundred and fifty-three (89%) paired morning-afternoon records were completed and analysed. Data was compared to that of similar courses five years earlier. RESULTS: The mean (SD) pre- and post-course percentage scores were 33.8 (13.5) and 63.6 (14.6). The mean improvement was 29.8 percentage points (SD 11.7). The pre-post correlation was +0.66. At baseline only six (2.4%) of the 253 practitioners achieved the preset standard. After the course, 146 (57.7%) did so, an improvement of 55.3% (95% CI 48.9-61.3%). The final score and score gain were slightly higher in more recent graduates. The increase in proportion attaining the standard following training was 11.9% higher for IRMER than for POPUMET (p <0.001). CONCLUSION: The level of knowledge in radiation protection was very low at baseline. Whilst attending the approved course led to considerable improvement, it did not invariably result in a satisfactory level of knowledge in fundamental radiation physics and regulations. The prescribed standard was achieved by less than 60% of the attendees. The IRMER course was significantly more effective than its POPUMET predecessor.

Laparoscopic calicovesicostomy: a novel surgical procedure.

Laparoscopic calicovesicostomy in the horseshoe kidney with ureteropelvic junction obstruction associated with ipsilateral ureteral duplication and a large-capacity bladder is described. The intraoperative and postoperative clinical parameters were satisfactory in this preliminary report. Additional studies are necessary to evaluate this novel surgical procedure.

Ectopic adrenal tissue as radiographic lymphadenopathy in renal cell carcinoma.

In the presence of solid, contrast-enhancing renal mass, concomitant contrast-enhancing retroperitoneal mass is usually viewed as regional lymph node metastasis unless proven otherwise. The present report of ectopic adrenal tissue demonstrates that the presence of retroperitoneal contrast-enhancing mass may be a benign finding in patients with renal malignancy. Pathology remains the definitive method for diagnosis in such situation.

Laparoscopic Mitrofanoff appendicovesicostomy.

A novel technique of performing fully laparoscopic Mitrofanoff appendicovesicostomy in the management of neurogenic bladder is described. All steps, including appendix harvesting and extravesical appendiceal-vesical anastomosis with flap-valve mechanism creation, were completed laparoscopically and provided satisfactory preliminary clinical results. Additional studies are necessary for the evaluation of this novel technique.

A novel open surgical approach to transvesical distal ureterectomy in nephroureterectomy.

A single-incision transvesical approach to open distal ureterectomy is described herein. The surgical technique has been applied successfully to 6 consecutive patients undergoing laparoscopic nephrectomy with open distal ureterectomy for upper tract transitional cell carcinoma. The technique presented allows easy and effective excision of the ipsilateral distal ureter, ureteral orifice, and bladder cuff as well as closure of the single cystotomy. Further studies with long-term follow-up data are necessary to confirm the satisfactory preliminary clinical experience presented in this report.