Impact of data transfer between treatment planning systems on dosimetric parameters.

PURPOSE: In radiotherapy it is often necessary to transfer a patient's DICOM (Digital Imaging and COmmunications in Medicine) dataset from one system to another for re-treatment, plan-summation or registration purposes. The aim of the study is to evaluate effects of dataset transfer between treatment planning systems. MATERIALS AND METHODS: Twenty-five patients treated in a 0.35T MR-Linac (MRidian, ViewRay) for locally-advanced pancreatic cancer were enrolled. For each patient, a nominal dose distribution was optimized on the planning MRI. Each plan was daily re-optimized if needed to match the anatomy and exported from MRIdian-TPS (ViewRay Inc.) to Eclipse-TPS (Siemens-Varian). A comparison between the two TPSs was performed considering the PTV and OARs volumes (cc), as well as dose coverages and clinical constraints. RESULTS: From the twenty-five enrolled patients, 139 plans were included in the data comparison. The median values of percentage PTV volume variation are 10.8 % for each fraction, while percentage differences of PTV coverage have a mean value of -1.4 %. The median values of the percentage OARs volume variation are 16.0 %, 7.0 %, 10.4 % and 8.5 % for duodenum, stomach, small and large bowel, respectively. The percentage variations of the dose constraints are 41.0 %, 52.7 % and 49.8 % for duodenum, stomach and small bowel, respectively. CONCLUSIONS: This study has demonstrated a non-negligible variation in size and dosimetric parameters when datasets are transferred between TPSs. Such variations should be clinically considered. Investigations are focused on DICOM structure algorithm employed by the TPSs during the transfer to understand the cause of such variations.

Why we should care about gas pockets in online adaptive MRgRT: a dosimetric evaluation.

Introduction: Contouring of gas pockets is a time consuming step in the workflow of adaptive radiotherapy. We would like to better understand which gas pockets electronic densitiy should be used and the dosimetric impact on adaptive MRgRT treatment. Materials and methods: 21 CT scans of patients undergoing SBRT were retrospectively evaluated. Anatomical structures were contoured: Gross Tumour Volume (GTV), stomach (ST), small bowel (SB), large bowel (LB), gas pockets (GAS) and gas in each organ respectively STG, SBG, LBG. Average HU in GAS was converted in RED, the obtained value has been named as Gastrointestinal Gas RED (GIGED). Differences of average HU in GAS, STG, SBG and LBG were computed. Three treatment plans were calculated editing the GAS volume RED that was overwritten with: air RED (0.0012), water RED (1.000), GIGED, generating respectively APLAN, WPLAN and the GPLAN. 2-D dose distributions were analyzed by gamma analysis. Parameter called active gas volume (AGV) was calculated as the intersection of GAS with the isodose of 5% of prescription dose. Results: Average HU value contained in GAS results to be equal to -620. No significative difference was noted between the average HU of gas in different organ at risk. Value of Gamma Passing Rate (GPR) anticorrelates with the AGV for each plan comparison and the threshold value for GPR to fall below 90% is 41, 60 and 139 cc for WPLANvsAPLAN, GPLANvsAPLAN and WPLANvsGPLAN respectively. Discussions: GIGED is the right RED for Gastrointestinal Gas. Novel AGV is a useful parameter to evaluate the effect of gas pocket on dose distribution.

Innovations in imaging modalities: a comparative review of MRI, long-axial field-of-view PET, and full-ring CZT-SPECT in detecting bone metastases.

The accurate diagnosis of bone metastasis, a condition in which cancer cells have spread to the bone, is essential for optimal patient care and outcome. This review provides a detailed overview of the current medical imaging techniques used to detect and diagnose this critical condition focusing on three cardinal imaging modalities: positron emission tomography (PET), single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI). Each of these techniques has unique advantages: PET/CT combines functional imaging with anatomical imaging, allowing precise localization of metabolic abnormalities; the SPECT/CT offers a wider range of radiopharmaceuticals for visualizing specific receptors and metabolic pathways; MRI stands out for its unparalleled ability to produce high-resolution images of bone marrow structures. However, as this paper shows, each modality has its own limitations. The comprehensive analysis does not stop at the technical aspects, but ventures into the wider implications of these techniques in a clinical setting. By understanding the synergies and shortcomings of these modalities, healthcare professionals can make diagnostic and therapeutic decisions. Furthermore, at a time when medical technology is evolving at a breakneck pace, this review casts a speculative eye towards future advances in the field of bone metastasis imaging, bridging the current state with future possibilities. Such insights are essential for both clinicians and researchers navigating the complex landscape of bone metastasis diagnosis.

Synchronous Treatment of Breast Cancer Hepatic Metastases by Transarterial Radioembolization and Radiofrequency Thermoablation: A Case Report.

ABSTRACT: In a 51-year-old woman affected by breast cancer, hepatic recurrence of disease was managed by concurrent 90 Y-labeled glass microsphere embolization (transarterial radioembolization) and radiofrequency thermoablation. Intention-to-treat target, candidate to radioembolization, was in the IV hepatic segment; another lesion, managed with radiofrequency thermoablation, was in the VI-VII hepatic segment. Concomitant correction of a duodenocephalopancreatic shunting was performed as well. Thermoablation did not interfere with distribution of 99m Tc-macroaggregated albumin and 90 Y-labeled microspheres to the target and healthy liver. At our knowledge, this is the first report that combines 2 locoregional procedures in different hepatic segments on the same day.

Dose-response Analysis in Hepatic Tumors Treated with 90Y-TARE According to a Personalized Dosimetric Workflow: Preliminary Results.

BACKGROUND: Transarterial Radioembolization (TARE) is a widespread radiation therapy for unresectable hepatic lesions, but a clear understanding of the dose-response link is still missing. The aim of this preliminary study is to investigate the role of both dosimetric and clinical parameters as classifiers or predictors of response and survival for TARE in hepatic tumors and to present possible response cut-off. METHODS: 20 patients treated with glass or resin microspheres according to a personalized workflow were included. Dosimetric parameters were extracted from personalized absorbed dose maps obtained from the convolution of 90Y PET images with 90Y voxel S-values. RESULTS: D95 ≥ 104 Gy and tumor mean absorbed dose MADt ≥ 229 Gy were found to be optimal cut-off values for complete response, while D30 ≥ 180 Gy and MADt ≥ 117 Gy were selected as cut-off values for at least partial response and predicted better survival. Clinical parameters Alanine Transaminase (ALT) and Model for End-Stage Liver Disease (MELD) didn't show sufficient classification capability for response or survival. CONCUSION: These preliminary results highlight the importance of an accurate dosimetric evaluation and suggest a cautious approach when considering clinical indicators. Dosimetric cut-off values could be a support tool in both planning and post-treatment phases. Larger multi-centric randomized trials, with standardized methods regarding patient selection, response criteria, Regions of Interest definition, dosimetric approach and activity planning are needed to confirm these promising results.

Automation of pencil beam scanning proton treatment planning for intracranial tumours.

PURPOSE: To evaluate the feasibility of comprehensive automation of an intra-cranial proton treatment planning. MATERIALS AND METHODS: Class solution (CS) beam configuration selection allows the user to identify predefined beam configuration based on target localization; automatic CS (aCS) will then explore all the possible CS beam geometries. Ten patients, already used for the evaluation of the automatic selection of the beam configuration, have been also employed to training an algorithm based on the computation of a benchmark dose exploit automatic general planning solution (GPS) optimization with a wish list approach for the planning optimization. An independent cohort of ten patients has been then used for the evaluation step between the clinical and the GPS plan in terms of dosimetric quality of plans and the time needed to generate a plan. RESULTS: The definition of a beam configuration requires on average 22 min (range 9-29 min). The average time for GPS plan generation is 18 min (range 7-26 min). Median dose differences (GPS-Manual) for each OAR constraints are: brainstem -1.60 Gy, left cochlea -1.22 Gy, right cochlea -1.42 Gy, left eye 0.55 Gy, right eye -2.33 Gy, optic chiasm -1.87 Gy, left optic nerve -4.45 Gy, right optic nerve -2.48 Gy and optic tract -0.31 Gy. Dosimetric CS and aCS plan evaluation shows a slightly worsening of the OARs values except for the optic tract and optic chiasm for both CS and aCS, where better results have been observed. CONCLUSION: This study has shown the feasibility and implementation of the automatic planning system for intracranial tumors. The method developed in this work is ready to be implemented in a clinical workflow.

A DROP-IN beta probe for robot-assisted 68Ga-PSMA radioguided surgery: first ex vivo technology evaluation using prostate cancer specimens.

BACKGROUND: Recently, a flexible DROP-IN gamma-probe was introduced for robot-assisted radioguided surgery, using traditional low-energy SPECT-isotopes. In parallel, a novel approach to achieve sensitive radioguidance using beta-emitting PET isotopes has been proposed. Integration of these two concepts would allow to exploit the use of PET tracers during robot-assisted tumor-receptor-targeted. In this study, we have engineered and validated the performance of a novel DROP-IN beta particle (DROP-INß) detector. METHODS: Seven prostate cancer patients with PSMA-PET positive tumors received an additional intraoperative injection of ~ 70 MBq 68Ga-PSMA-11, followed by robot-assisted prostatectomy and extended pelvic lymph node dissection. The surgical specimens from these procedures were used to validate the performance of our DROP-INß probe prototype, which merged a scintillating detector with a housing optimized for a 12-mm trocar and prograsp instruments. RESULTS: After optimization of the detector and probe housing via Monte Carlo simulations, the resulting DROP-INß probe prototype was tested in a robotic setting. In the ex vivo setting, the probe-positioned by the robot-was able to identify 68Ga-PSMA-11 containing hot-spots in the surgical specimens: signal-to-background (S/B) was > 5 when pathology confirmed that the tumor was located < 1 mm below the specimen surface. 68Ga-PSMA-11 containing (and PET positive) lymph nodes, as found in two patients, were also confirmed with the DROP-INß probe (S/B > 3). The rotational freedom of the DROP-IN design and the ability to manipulate the probe with the prograsp tool allowed the surgeon to perform autonomous beta-tracing. CONCLUSIONS: This study demonstrates the feasibility of beta-radioguided surgery in a robotic context by means of a DROP-INß detector. When translated to an in vivo setting in the future, this technique could provide a valuable tool in detecting tumor remnants on the prostate surface and in confirmation of PSMA-PET positive lymph nodes.

Delphi consensus on the monitoring tools of main individual risk factors for chronic diseases by the company doctor. / Ricerca di consenso Delphi sugli strumenti per il monitoraggio da parte del medico competente dei principali fattori di rischio individuali per malattie croniche.

BACKGROUND: Data on individual risk factors for chronic diseases (smoking, physical activity, body mass) are collected by company physicians in heterogeneous ways. This makes comparisons, researches and evaluations difficult. OBJECTIVES: The aim of the study was to find a consensus on evaluation tools for chronic diseases risk factors and for health promotion programs in workplaces that could be performed by company physicians during their clinical activity. METHODS: A first set of tools, proposed by a working group of occupational physicians in Bergamo, was submitted through the Delphi technique to a national expert panel of 22 persons including recognized national experts in specific fields and occupational physicians skilled in health promotion. RESULTS: In three Delphi rounds, the panel selected a set of tools to monitor the main individual risk factors for chronic diseases (smoking, alcohol, physical activity, nutrition, stress and mental health) as well as general data related to the worker and his job. CONCLUSIONS: The use of these specific tools, collected in a homogeneous format, should be recommended to all Italian company physicians, in particular those who work in WHP-programs, in order to allow analysis, comparison and evaluation of health promotion programs effectiveness at a national level.

[Assessment of the impact over one year of a workplace health promotion programme in the province of Bergamo]. / Stima dell's effecto ad un anno di un programma di promozione della salute nei luoghi di lavoro in provincia di Bergamo.

OBJECTIVES: To estimate short-term effects of integrated health promotion in the workplace within the framework of the Bergamo WHP (Workplace Health Promotion) network, which involves 94 companies and about 21,000 workers. METHODS: A controlled non-randomized, before-after evaluation was carried out. Data were collected through anonymous questionnaires before (t0) and after participation in a 12-month health promotion programme (t1). The "control" group consisted of workers of companies participating in the programme who had not yet undertaken any interventions in the theme areas covered by the assessment. RESULTS: In the workers participating in the programme, positive early effects (after 12 months) were related to intake of food providing protection (fruit and vegetables) and increased rates of smoking cessation. The effects were more evident in males and in white collars. The physical activity and alcohol consumption trends went in the desired direction and with more effects than in the non-participating group, but without statistical significance. In the short term, no evident changes in events of road injury risk or in the quality of personal relationships were seen, probably due to the small size of the sample involved in these study areas. CONCLUSIONS: The results, although within the methodological limitations of the study, showed that after 12 months there was a reduction in some important risk factors for chronic diseases in workers participating in the programme, particularly for fruit and vegetable intake and smoking cessation. It will be important to monitor the effects of the programme on other risk factors in the medium and long term, and also the impact of employment status and gender so as to adjust the programme interventions accordingly. Cooperation with occupational/authorized physicians with use of their data collected from health surveillance, together with a limited set of general risk factor indicators, would be a desirable development for further studies.

Improved 5-year survival of patients with immunochemical faecal blood test-screen-detected colorectal cancer versus non-screening cancers in northern Italy.

BACKGROUND: Colorectal cancer screening may reduce disease-related mortality by early-stage detection of cancers. AIMS: To study the effect of a single immunochemical faecal occult blood test (i-FOBt) screening round on reduction in colorectal cancer-related-mortality among average risk subjects. METHODS: Comparison of 5-year mortality rates in 3 cohorts from a Northern Italian province: (1) colorectal cancers detected at the 1st biennial round of a mass-screening programme targeting 50-69 years old subjects, (2) non-screening cancers symptomatically diagnosed during the same time period, and (3) cancers detected in the pre-screening biennium. Multivariate analyses were performed with the Cox regression model including tumour node metastasis (TNM) stage at diagnosis, anatomical distribution of cancers, age at diagnosis, gender and patient group. Kaplan-Meyer survival estimates and log-rank test for equality of survivor functions were calculated. RESULTS: Stage distribution significantly differed between screening and non-screening colorectal cancers: 73% of screen-detected colorectal cancers were stages I and II versus 43% and 40% of non-screening and pre-screening colorectal cancers. Cumulative 5-year mortality rate was significantly lower in screening compared to non-screening or pre-screening colorectal cancers patients (19% versus 37% and 41%, p < 0.001). CONCLUSIONS: Colorectal cancers were detected at earlier stages in i-FOBT-positive subjects in comparison with non-screening patients; colorectal cancers found at screening had a significantly improved 5-year survival.

A combination of faecal tests for the detection of colon cancer: a new strategy for an appropriate selection of referrals to colonoscopy? A prospective multicentre Italian study.

INTRODUCTION: Colonoscopy workload for endoscopy services in Western countries is increasing markedly because of the implementation of faecal occult blood-based mass screening programmes against colorectal cancer (CRC). We therefore explored the possibility of using a combination of faecal tests to prioritize the access to colonoscopy with criteria other than symptoms and/or time of referral. AIMS AND METHODS: We tested a combination of faecal tests [immunochemical faecal occult blood test (i-FOBT), M2-PK, calprotectin] as markers for advanced neoplasia in a selected series of patients requiring colonoscopy for the suspicion of CRC. All the tests were performed in a 1-day stool sample of patients aged 50-80 years, without any dietary restriction, before colonoscopy. RESULTS: A total of 280 patients' stool single samples were analysed. Forty-seven patients had CRC and 85 patients had one or more advanced adenoma(s) at colonoscopy/histology. CRCs were associated with a highly significant increase (P<0.001) in faecal tumour M2-PK (mean 24.2 kU/l), which correlated with Dukes' staging. For CRC detection, i-FOBT was the test with the highest specificity and positive predictive value (0.89 and 0.53), whereas M2-PK had the highest sensitivity and negative predictive value (0.87 and 0.96). Calprotectin showed performance similar to M2-PK in terms of sensitivity and negative predictive value (0.93), but had lower specificity (0.39). The best combination of tests to predict the risk of CRC in this series was i-FOBT+M2-PK, as in patients showing positivity to both markers, the risk of cancer was as high as 79%. CONCLUSION: The combination of i-FOBT and M2-PK is a sensitive tool in clinical practice for the appropriate management of waiting lists for colonoscopy, as it allows the classification of patients into different degrees of priority for investigation, according to their foreseeable risk of CRC.

[Workplace health promotion: description and preliminary results of ASL of Bergamo integrated]. / Promuovere la salute in azienda: descrizione e primi risultati di un intervento interdiscliplinare dell'ASL di Bergamo.

Interventions for health promotion in the workplace (WHP programs) can improve the health of workers, acting on modifiable risk factors for chronic diseases. The effectiveness of integrated programs of health promotion in companies is well described in literature. Our project was conducted in two mid-sized companies in the province of Bergamo, respectively with 170 and 230 employees. The project issues were in the following areas: tobacco smoke (awareness and support to smoking cessation); nutrition (awareness and practical action on the workplace canteen); physical activity (awareness, information and practical ways of incentives); prevention of road accidents (training and initiatives to promote safety). The analysis of the behaviours and individual risk factors was performed by a questionnaire at the beginning of the project and a year later. 95 initial questionnaires were returned and processed for the company A and 168 for the company B; their results were discussed with company management, the company doctors and workers representatives and allowed the formulation of a "company assessment risk profile" according to the methodology of the Assessment of Health Risks with Feedback (AHRF). There have been training/awareness messages in working hours for all employees on areas of lifestyle and have started work on the canteen, actions to promote road safety, physical activity and interventions to counter the smoking. The effectiveness of group treatments for smoking cessation has been of 55.6% at 3 months and 50% at 6 months (at the present only a company has achieved 6 months of follow up).

Impact of a population-based colorectal cancer screening program on local health services demand in Italy: a 7-year survey in a northern province.

OBJECTIVES: In 2005, the National Health Service recommended a population-based colorectal cancer (CRC) screening program using biennial fecal occult blood testing (FOBT), followed by total colonoscopy in positive patients. So far, no studies have been performed to evaluate the impact of a mass-screening CRC campaign on the health system services at the community level in Italy. We have therefore assessed the workload generated by the first two biennial rounds of screening program on the activity of hospital services involved in CRC diagnosis in the Lecco province. METHODS: Routine data from all hospital services of our province were collected on activity levels related to CRC diagnosis from January 2003 to December 2009. This time span covered the 2 years prior to, as well as the two biennial rounds of the CRC screening program. In particular, we focused on the volume of outpatient FOBTs and colonoscopies (both diagnostic and interventional) performed among subjects outside the screening program. Joinpoint models were used to test whether an apparent change in trend of examination over time was statistically significant in different age cohorts of the population (<50 years, 50-69 years, and ≥70 years). RESULTS: The volume of "extra-screening" per-patient/FOBTs and colonoscopies increased significantly over the evaluated periods in all ages, until year 2008, when a steady trend was beginning; the AAPCs (average of the annual percent changes) values were 5.7, 3.1, and 8.4 for FOBT and 14.6, 13.4, and 16.7 for colonoscopy in the three age cohorts, respectively. However, the increase in both FOBT and colonoscopy demand was maximal in the cohort ≥70 years, where three statistically significant annual percent changes (APCs) were identified (in 2003-2005, 2005-2006, and 2006-2007 APCs were 12.3, 14.9, and 15.9 for FOBT, and 18.7, 36.8, and 25.4 for colonoscopy, respectively). CONCLUSIONS: After the implementation of a FOBT-based mass-screening program for CRC, careful consideration must be given to the significant increase in the workload of hospital services involved in CRC diagnosis, outside the screening campaign. The extra-work mainly involves gastroenterologists performing colonoscopy, whose activity increased over the 5-year period by 118%, as well as laboratory services, where the demand of FOBTs rose by 40%. This phenomenon, mainly attributable to a profound change in the attitude toward CRC screening by those age cohorts outside the program, covers a time span of two full rounds of screening, whereupon a steady trend for colonoscopy is apparent.

Caracterização físico-química de bebida protéica elaborada com extrato de soja e polpa de pêssegos / Physico-chemical characterization of proteic beverage elaborated with soymilk and peaches pulp

Este trabalho objetivou a caracterização a caracterização físico-química de bebida elaborada com extrato de soja e polpa de pêssegos, com teor protéico de soja (2 por cento) mais elevado que o encontrado em bebidas similares no mercado. Os resultados demonstraram que a bebida manteve todos os constituintes da composição físico-química da matéria-prima original (teores de proteinas e lipídeos da soja, e de açúcares, fibras e ácido ascórbico da fruta). A bebida apresentou grande parte dos aminoácidos essenciais, entre 73 e 91 por cento do padrão estabelecido pela FAO, sendo que a fruta contribuiu para o incremento do teor de aminoácidos não-essenciais. Os oligossacarídeos e isoflavonas mantiveram-se na bebida proporcionalmente ao extrato de soja e a quantidade de proteínas e de isoflavonas totais mostrou-se superior a das bebidas similares disponíveis no mercado

Retrospective analysis of 736 implants inserted without antibiotic therapy.

PURPOSE: The routine use of antibiotics in oral implant treatment seems to be widespread. The principle of antibiotic prophylaxis before oral surgical procedures in patients at risk for endocarditis or in those who are severely immunocompromised is well established. Antibiotic therapy in conjunction with implant surgery in fit patients and its correlation with failure and success rates remains poorly documented, however. The debate regarding overprescription of antibiotics raises the need for a critical evaluation of proper antibiotic coverage in association with implant treatment. The purpose of this study was to retrospectively show and value the outcomes of dental implant treatment without antibiotic prophylaxis. MATERIALS AND METHODS: The study included 437 consecutively treated patients, in whom a total of 736 implants were placed. The population received no prophylactic antibiotics, but received anti-inflammatory therapy (nimesulide 100 mg twice daily or Arnica montana 5C 3 times a day) for 3 days postoperatively. Healing was evaluated at second-stage surgery (4 to 6 months postoperatively). Failure was defined as removal of the implant due to either signs of infection or nonosseointegration of the implant, according to the criteria for success described by Albrektsson and Coll in 1988. RESULTS: The implant survival rate in the sample (96.2%) was no lower than the high success rates published in the literature using various antibiotic regimens. CONCLUSIONS: Our findings support the results of several recent reviews of minor use of antibiotics in oral surgery. These findings suggest that the use of antibiotics for routine oral implants may not be as beneficial as once believed and that clinicians should look forward to the reduction of their unnecessary use. The use of antibiotic prophylaxis before oral surgical procedures remains a controversial issue, poorly documented in the literature.

Incidence and risk factors for gallstones in patients with inflammatory bowel disease: a large case-control study.

UNLABELLED: The risk for gallstones (GD) in inflammatory bowel diseases and the factors responsible for this complication have not been well established. We studied the incidence of GD in a cohort of Crohn's disease (CD) and ulcerative colitis (UC) patients and investigated the related risk factors. A case-controlled study was carried out. The study population included 634 inflammatory bowel disease (IBD) patients (429 CD, 205 UC) and 634 age-matched, sex-matched, and body mass index (BMI)-matched controls free of GD at enrollment, who were followed for a mean of 7.2 years (range, 5-11 years). The incidence of GD was calculated by dividing the number of events per person-years of follow-up. Multivariate analysis was used to discriminate among the impact of different variables on the risk of developing GD. The incidence rates of GD were 14.35/1,000 persons/year in CD as compared with 7.75 in matched controls (P=0.012) and 7.48/1000 persons/year in UC patients as compared with 6.06 in matched-controls (P=0.38). Ileo-colonic CD location (OR, 2.14), disease duration>15 years (OR, 4.26), >3 clinical recurrences (OR, 8.07), ileal resection>30 cm (OR, 7.03), >3 hospitalizations (OR, 20.7), multiple TPN treatments (OR, 8.07), and long hospital stay (OR, 24.8) were significantly related to GD in CD patients. CONCLUSION: Only CD patients have a significantly higher risk of developing GD than well-matched hospital controls. Site of disease at diagnosis, lifetime surgery, extent of ileal resections, number of clinical recurrences, TPN, and the frequency and duration of hospitalizations are independently associated with GD.

Conformational dimorphism of self-peptides and molecular mimicry in a disease-associated HLA-B27 subtype.

An interesting property of certain peptides presented by major histocompatibility complex (MHC) molecules is their acquisition of a dual binding mode within the peptide binding groove. Using x-ray crystallography at 1.4 A resolution, we show here that the glucagon receptor-derived self-peptide pGR ((412)RRRWHRWRL(420)) is presented by the disease-associated human MHC class I subtype HLA-B*2705 in a dual conformation as well, with the middle of the peptide bent toward the floor of the peptide binding groove of the molecule in both binding modes. The conformations of pGR are compared here with those of another self-peptide (pVIPR, RRKWRRWHL) that is also displayed in two binding modes by HLA-B*2705 antigens and with that of the viral peptide pLMP2 (RRRWRRLTV). Conserved structural features suggest that the N-terminal halves of the peptides are crucial in allowing cytotoxic T lymphocyte (CTL) cross-reactivity. In addition, an analysis of T cell receptors (TCRs) from pGR- or pVIPR-directed, HLA-B27-restricted CTL clones demonstrates that TCR from distinct clones but with comparable reactivity may share CDR3alpha but not CDR3beta regions. Therefore, the cross-reactivity of these CTLs depends on TCR-CDR3alpha, is modulated by TCR-CDR3beta sequences, and is ultimately a consequence of the conformational dimorphism that characterizes binding of the self-peptides to HLA-B*2705. These results lend support to the concept that conformational dimorphisms of MHC class I-bound peptides might be connected with the occurrence of self-reactive CTL.

Novel repair for late posttraumatic aortic valve injury and root pseudoaneurysm.

We report a case of posttraumatic aortic valve regurgitation and pseudoaneurysm of the aortic root diagnosed 22 months after a road traffic accident. The surgical treatment consisted of exclusion of the pseudoaneurysm with direct closure of the entry tear in the right coronary sinus followed by insertion of a Toronto stentless prosthesis (St. Jude Medical, St. Paul, MN). This surgical approach aimed to cover the repaired entry tear ensuring exclusion of the site. Recovery was uneventful and 12 month follow-up was unremarkable.