Generating multiple random exams using mathematica package and LATEX

[EN]In the framework of the European Higher Education Area, the assessment has been one of the most important aspects considered. In the Spanish Universities, one of the main differences with regard to the previous system is the incorporation of the continuous assessment to the evaluation process that is understood in several ways depending on the Universities, the courses and the lecturers. Focus on our context, a course of Mathematics of the first academic year in the Faculty of Business Administration at the University of Las Palmas de Gran Canaria (Spain), the continuous assessment has brought the preparation of a large amount of different tests to evaluate the students enrolled in it, therefore the incorporation of new tools and skills in order to make the teaching–learning process easier and more dynamic has become a need mainly in those degrees with a large number of students as the case we consider here. In this work we provide an efficient and effective way to elaborate random multiple-choice examina tion tests (although essay exams are also possible) by using Mathematica package and LATEXin order to make easier to the lectures the preparation of a large number of mid-term tests for a large number of students.

Surgical dislocation of the hip for the fixation of acetabular fractures

Surgical dislocation of the hip in the treatment of acetabular fractures allows the femoral head to be safely displaced from the acetabulum. This permits full intra-articular acetabular and femoral inspection for the evaluation and potential treatment of cartilage lesions of the labrum and femoral head, reduction of the fracture under direct vision and avoidance of intra-articular penetration with hardware. We report 60 patients with selected types of acetabular fracture who were treated using this approach. Six were lost to follow-up and the remaining 54 were available for clinical and radiological review at a mean follow-up of 4.4 years (2 to 9). Substantial damage to the intra-articular cartilage was found in the anteromedial portion of the femoral head and the posterosuperior aspect of the acetabulum. Labral lesions were predominantly seen in the posterior acetabular area. Anatomical reduction was achieved in 50 hips (93%) which was considerably higher than that seen in previous reports. There were no cases of avascular necrosis. Four patients subsequently required total hip replacement. Good or excellent results were achieved in 44 hips (81.5%). The cumulative eight-year survivorship was 89.0% (95% confidence interval 84.5 to 94.1). Significant predictors of poor outcome were involvement of the acetabular dome and lesions of the femoral cartilage greater than grade 2. The functional mid-term results were better than those of previous reports. Surgical dislocation of the hip allows accurate reduction and a predictable mid-term outcome in the management of these difficult injuries without the risk of the development of avascular necrosis.

Long-term results after proximal thoracic aortic redo surgery

Objective: To evaluate early and mid-term results in patients undergoing proximal thoracic aortic redo surgery. Methods: We analyzed 60 patients (median age 60 years, median logistic EuroSCORE 40) who underwent proximal thoracic aortic redo surgery between January 2005 and April 2012. Outcome and risk factors were analyzed. Results: In hospital mortality was 13%, perioperative neurologic injury was 7%. Fifty percent of patients underwent redo surgery in an urgent or emergency setting. In 65%, partial or total arch replacement with or without conventional or frozen elephant trunk extension was performed. The preoperative logistic EuroSCORE I confirmed to be a reliable predictor of adverse outcome- (ROC 0.786, 95%CI 0.64–0.93) as did the new EuroSCORE II model: ROC 0.882 95%CI 0.78–0.98. Extensive individual logistic EuroSCORE I levels more than 67 showed an OR of 7.01, 95%CI 1.43–34.27. A EuroSCORE II larger than 28 showed an OR of 4.44 (95%CI 1.4–14.06). Multivariate logistic regression analysis identified a critical preoperative state (OR 7.96, 95%CI 1.51–38.79) but not advanced age (OR 2.46, 95%CI 0.48–12.66) as the strongest independent predictor of in-hospital mortality. Median follow-up was 23 months (1–52 months). One year and five year actuarial survival rates were 83% and 69% respectively. Freedom from reoperation during follow-up was 100%. Conclusions: Despite a substantial early attrition rate in patients presenting with a critical preoperative state, proximal thoracic aortic redo surgery provides excellent early and mid-term results. Higher EuroSCORE I and II levels and a critical preoperative state but not advanced age are independent predictors of in-hospital mortality. As a consequence, age alone should no longer be regarded as a contraindication for surgical treatment in this particular group of patient

Multimodal treatment for high-risk prostate cancer with high-dose intensity-modulated radiation therapy preceded or not by radical prostatectomy, concurrent intensified-dose docetaxel and long-term androgen deprivation therapy: results of a prospective phase II trial.

BACKGROUND The optimal management of high-risk prostate cancer remains uncertain. In this study we assessed the safety and efficacy of a novel multimodal treatment paradigm for high-risk prostate cancer. METHODS This was a prospective phase II trial including 35 patients with newly diagnosed high-risk localized or locally advanced prostate cancer treated with high-dose intensity-modulated radiation therapy preceded or not by radical prostatectomy, concurrent intensified-dose docetaxel-based chemotherapy and long-term androgen deprivation therapy. Primary endpoint was acute and late toxicity evaluated with the Common Terminology Criteria for Adverse Events version 3.0. Secondary endpoint was biochemical and clinical recurrence-free survival explored with the Kaplan-Meier method. RESULTS Acute gastro-intestinal and genito-urinary toxicity was grade 2 in 23% and 20% of patients, and grade 3 in 9% and 3% of patients, respectively. Acute blood/bone marrow toxicity was grade 2 in 20% of patients. No acute grade ≥ 4 toxicity was observed. Late gastro-intestinal and genito-urinary toxicity was grade 2 in 9% of patients each. No late grade ≥ 3 toxicity was observed. Median follow-up was 63 months (interquartile range 31-79). Actuarial 5-year biochemical and clinical recurrence-free survival rate was 55% (95% confidence interval, 35-75%) and 70% (95% confidence interval, 52-88%), respectively. CONCLUSIONS In our phase II trial testing a novel multimodal treatment paradigm for high-risk prostate cancer, toxicity was acceptably low and mid-term oncological outcome was good. This treatment paradigm, thus, may warrant further evaluation in phase III randomized trials.

Is surgery in acute aortic dissection type A still contraindicated in the presence of preoperative neurological symptoms?

OBJECTIVES Severe neurological deficit (ND) due to acute aortic dissection type A (AADA) was considered a contraindication for surgery because of poor prognosis. Recently, more aggressive indication for surgery despite neurological symptoms has shown acceptable postoperative clinical results. The aim of this study was to evaluate early and mid-term outcomes of patients with AADA presenting with acute ND. METHODS Data from 53 patients with new-onset ND who received surgical repair for AADA between 2005 and 2012 at our institution were retrospectively reviewed. ND was defined as focal motor or sensory deficit, hemiplegia, paraplegia, convulsions or coma. Neurological symptoms were evaluated preoperatively using the Glasgow Coma Scale (GCS) and modified Rankin Scale (mRS), and at discharge as well as 3-6 months postoperatively using the mRS and National Institutes of Health Stroke Scale. Involvement of carotid arteries was assessed in the pre- and postoperative computed tomography. Logistic regression analysis was performed to detect predictive factors for recovery of ND. RESULTS Of the 53 patients, 29 (54.7%) showed complete recovery from focal ND at follow-up. Neurological symptoms persisted in 24 (45.3%) patients, of which 8 (33%) died without neurological assessment at follow-up. Between the two groups (patients with recovery and those with persisting ND), there was no significant difference regarding the duration of hypothermic circulatory arrest (28 ± 14 vs 36 ± 20 min) or severely reduced consciousness (GCS <8). Multivariate analysis showed significant differences for the preoperative mRS between the two groups (P < 0.007). A high preoperative mRS was associated with persistence of neurological symptoms (P < 0.02). Cardiovascular risk factors, age or involvement of supra-aortic branches were not predictive for persistence of ND. CONCLUSION More than half of our patients recovered completely from ND due to AADA after surgery. Severity of clinical symptoms had a predictive value. Patients suffering from AADA and presenting with ND before surgery should not be excluded from emergency surgery.

A Baseline Wander Tracking System for Artifact Rejection in Long-Term Electrocardiography

Long-term electrocardiogram (ECG) signals might suffer from relevant baseline disturbances during physical activity. Motion artifacts in particular are more pronounced with dry surface or esophageal electrodes which are dedicated to prolonged ECG recording. In this paper we present a method called baseline wander tracking (BWT) that tracks and rejects strong baseline disturbances and avoids concurrent saturation of the analog front-end. The proposed algorithm shifts the baseline level of the ECG signal to the middle of the dynamic input range. Due to the fast offset shifts, that produce much steeper signal portions than the normal ECG waves, the true ECG signal can be reconstructed offline and filtered using computationally intensive algorithms. Based on Monte Carlo simulations we observed reconstruction errors mainly caused by the non-linearity inaccuracies of the DAC. However, the signal to error ratio of the BWT is higher compared to an analog front-end featuring a dynamic input ranges above 15 mV if a synthetic ECG signal was used. The BWT is additionally able to suppress (electrode) offset potentials without introducing long transients. Due to its structural simplicity, memory efficiency and the DC coupling capability, the BWT is dedicated to high integration required in long-term and low-power ECG recording systems.

Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care

OBJECTIVES: To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals. DATA SOURCES: Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present. HUMAN DATA SYNTHESIS: HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities. VETERINARY DATA SYNTHESIS: The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations. CONCLUSIONS: Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.

Interventional management of recurrent paroxysmal atrial fibrillation despite isolated pulmonary veins: impact of an ablation strategy targeting inducible atrial tachyarrhythmias

AIMS Pulmonary vein isolation (PVI) is an effective treatment option for paroxysmal atrial fibrillation (PAF). Reconnection of pulmonary veins (PVs) is the predominant cause for recurrence of PAF. However, treatment of patients with recurrence of PAF despite isolated PV in the absence of extra-PV foci remains challenging. METHODS AND RESULTS Of 265 patients undergoing repeat catheter ablation (CA) for recurrence of PAF 21 (8%) patients (14 men, age 58 ± 14 years) showed no reconnection of PV. Therefore, inducibility of sustained atrial arrhythmias was tested. If sustained atrial fibrillation (AF) or sustained atrial tachycardia (AT) was induced, patients underwent CA. During follow-up (FU), Holter- and Tele-electrocardiogram were performed. In 19 (91%) of 21 patients, sustained atrial arrhythmias [16 (84%) AF; 3 (15%) patients AT] were induced. One patient showed PAF. Eighteen patients underwent CA aiming for termination of induced arrhythmia. In 14 (77%) patients, termination into sinus rhythm was achieved. Despite extensive CA, three (16%) patients were externally cardioverted. No periprocedural complications occurred. During 21.2 ± 6.8-month FU, 10 (53%) patients were free of any arrhythmia. Paroxysmal atrial fibrillation recurred in 4 (21%) and AT in 5 (26%) patients. One patient showed persistent AF. Repeat CA was scheduled and successfully performed for these patients. CONCLUSION In patients with recurrence of PAF despite isolated PV, termination of induced atrial arrhythmias can be achieved in most patients by defragmentation and AT ablation. Moreover, this ablation strategy results in favourable mid-term outcome results.

Relative femoral neck lengthening improves pain and hip function in proximal femoral deformities with a high-riding trochanter

BACKGROUND Complex proximal femoral deformities, including an elevated greater trochanter, short femoral neck, and aspherical head-neck junction, often result in pain and impaired hip function resulting from intra-/extraarticular impingement. Relative femoral neck lengthening may address these deformities, but mid-term results of this approach have not been widely reported. QUESTIONS/PURPOSES Do patients who have undergone relative femoral neck lengthening show (1) less hip pain and greater function; (2) improved radiographic parameters; (3) significant complications requiring subsequent surgery; and (4) progression of osteoarthrosis (OA) or conversion to total hip arthroplasty (THA) at mid-term followup? METHODS We retrospectively reviewed 40 patients (41 hips) with isolated relative femoral neck lengthening between 1998 and 2006 with sequelae of Legg-Calvé-Perthes disease (38 hips [93%]), slipped capital femoral epiphysis (two hips [5%]), and postseptic arthritis (one hip [2%]). During this time, the general indications for this procedure included a high-riding greater trochanter with a short femoral neck with abductor weakness and symptomatic intra-/extraarticular impingement. Mean patient followup was 8 years (range, 5-13 years), and complete followup was available in 38 patients (39 hips [95%]). We evaluated pain and function with the impingement test, limp, abductor force, Merle d'Aubigné-Postel score, and range of motion. Radiographic parameters included trochanteric height, alpha angle, and progression of OA. Subsequent surgeries, complications, and conversion to THA were summarized. RESULTS The proportion of positive anterior impingement tests decreased from 93% (38 of 41 hips) preoperatively to 49% (17 of 35 hips) at latest followup (p = 0.002); the proportion of limp decreased from 76% (31 of 41 hips) to 9% (three of 35 hips; p < 0.001); the proportion of normal abductor strength increased from 17% (seven of 41 hips) to 91% (32 of 35 hips; p < 0.001); mean Merle d'Aubigné-Postel score increased from 14 ± 1.7 (range, 9-17) to 17 ± 1.5 (range, 13-18; p < 0.001); mean internal rotation increased to 25° ± 15° (range, 0°-60°; p = 0.045), external rotation to 32° ± 14° (range, 5°-70°; p = 0.013), and abduction to 37° ± 13° (range, 10°-50°; p = 0.004). Eighty percent of hips (33 of 41 hips) showed normal trochanteric height; alpha angle improved to 42° ± 10° (range, 27°-90°). Two hips (5%) had subsequent surgeries as a result of lack of containment; four of 41 hips (10%) had complications resulting in reoperation. Fourteen of 35 hips (40%) showed progression of OA; four of 40 hips (10%) converted to THA. CONCLUSIONS Relative femoral neck lengthening in hips with combined intra- and extraarticular impingement results in reduced pain, improved function, and improved radiographic parameters of the proximal femur. Although lack of long-term complications is gratifying, progression of OA was not prevented and remains an area for future research.

Supplemental cardioplegia immediately before graft implantation may improve early post-transplantation outcome

Gebiet: Chirurgie Abstract: Background: Preservation of cardiac grafts for transplantation is not standardized and most centers use a single administration of crystalloid solution at the time of harvesting. We investigated possible benefits of an additional dose of cardioplegia dispensed immediately before implantation. – – Methods: Consecutive adult cardiac transplantations (2005?2012) were reviewed. Hearts were harvested following a standard protocol (Celsior 2L, 4?8°C). In 2008, 100 ml crys-talloid cardioplegic solution was added and administered immediately before implanta-tion. Univariate and logistic regression analyses were used to investigate risk factors for post-operative graft failure and mid-term outcome. – – Results: A total of 81 patients, 44 standard (?Cardio???) vs. 37 with additional cardiople-gia (?CardioC?) were analyzed. Recipients and donors were comparable in both groups. CardioC patients demonstrated a reduced need for defibrillation (24 vs. 48%, p D0.03), post-operative ratio of CK-MB/CK (10.1_3.9 vs. 13.3_4.2%, p D0.001), intubation time (2.0_1.6 vs. 7.2_11.5 days, p D0.05), and ICU stay (3.9_2.1 vs. 8.5_7.8 days, p D0.001). Actuarial survival was reduced when graft ischemic time was >180 min in Cardio?? but not in CardioC patients (p D0.033). Organ ischemic time >180 min (OR: 5.48, CI: 1.08?27.75), donor female gender (OR: 5.84, CI: 1.13?33.01), and recipient/donor age >60 (OR: 6.33, CI: 0.86?46.75), but not the additional cardioplegia or the observation period appeared independent predictors of post-operative acute graft failure. – – Conclusion: An additional dose of cardioplegia administered immediately before implan-tation may be a simple way to improve early and late outcome of cardiac transplantation, especially in situations of prolonged graft ischemia.A large, ideally multicentric, randomized study is desirable to verify this preliminary observation.

Pitfalls and premature failure of the Freedom SOLO stentless valve

Gebiet: Chirurgie Abstract: Objectives This study reports a series of pitfalls, premature failures and explantations of the third generation Freedom SOLO bovine pericardial stentless valve. – – Methods 149 patients underwent aortic valve replacement (AVR) using the FS. Follow-up was 100% complete with an average observation time of 5.5±2.3 years (max. 8.7 years) and a total of 825 patient years. Following intraoperative documentation, all explanted valve prostheses underwent histological examination. – – Results Freedom from structural valve deterioration (SVD) at 5, 6, 7, 8 and 9 years was 92%, 88%, 80% and 70% and 62%, respectively. 14 prostheses required explantation due to valve-independent dysfunction (n=5, i.e. thrombus formation, oversizing, aortic dilatation, endocarditis and suture dehiscence) or valve-dependent failure (acute leaflet tears, n=4, severe stenosis, n=5). Thus freedom from explantation at 5, 6, 7, 8 and 9 years was 95%, 94%, 91% and 81% and 72%, respectively. An acute vertical tear along the non-coronary/right-coronary commissure to the base occurred at a mean of 6.0 years [range 4.3?7.3 years] and affected size 25 and 27 prostheses exclusively. Four FS required explantation after a mean of 7.5 years [range 7.0?8.3 years] due to severe functional stenosis and gross calcification that included the entire aortic root. – – Conclusions The Freedom SOLO stentless valve is safe to implant and shows satisfying mid-term results in our single institution experience. Freedom from SVD and explantation decreased markedly after only 6 ? 7 years, so that patients with FS require close observation and follow-up. Exact sizing, symmetric positioning and observing patient limitations are crucial for optimal outcome.

Is surgery in aCute aortiC disseCtion type A still ContraindiCated in the presenCe of preoperative neurologiCal symptoms?

Gebiet: Kardiologie Abstract: OBJECTIVES: Severe neurologiCal defiCit (ND) due to aCute aortiC disseCtion type A (AADA) was Considered a ContraindiCation for surgery beCause of poor prognosis. ReCently, more aggressive indiCation for surgery despite neurologiCal symptoms has shown aCCeptable – postoperative CliniCal results. The aim of this study was to evaluate early and mid-term outComes of patients with AADA presenting with aCute ND. – – METHODS: Data from 53 patients with new-onset ND who reCeived surgiCal repair for AADA between 2005 and 2012 at our institution were retrospeCtively reviewed. ND was defined as foCal motor or sensory defiCit, hemiplegia, paraplegia, Convulsions or Coma. NeurologiCal symptoms were evaluated preoperatively using the Glasgow Coma SCale (GCS) and modified Rankin SCale (mRS), and at disCharge as well as 3–6 months postoperatively using the mRS and National Institutes of Health Stroke SCale. Involvement of Carotid arteries was assessed in the pre- and postoperative Computed tomography. LogistiC regression analysis was performed to deteCt prediCtive faCtors for reCovery of ND. – – RESULTS: Of the 53 patients, 29 (54.7%) showed Complete reCovery from foCal ND at follow-up. NeurologiCal symptoms persisted in 24 (45.3%) patients, of whiCh 8 (33%) died without neurologiCal assessment at follow-up. Between the two groups (patients with reCovery and – those with persisting ND), there was no signifiCant differenCe regarding the duration of hypothermiC CirCulatory arrest (28 ± 14 vs 36 ± 20 min) or severely reduCed ConsCiousness (GCS <8). Multivariate analysis showed signifiCant differenCes for the preoperative mRS between the two groups (P < 0.007). A high preoperative mRS was assoCiated with persistenCe of neurologiCal symptoms (P < 0.02). CardiovasCular risk faCtors, age or involvement of supra-aortiC branChes were not prediCtive for persistenCe of ND. – – CONCLUSION: More than half of our patients reCovered Completely from ND due to AADA after surgery. Severity of CliniCal symptoms had a prediCtive value. Patients suffering from AADA and presenting with ND before surgery should not be exCluded from emergenCy surgery.

Short- and long-term efficacy and mechanism of action of tumescent suction curettage for axillary hyperhidrosis

BACKGROUND Axillary hyperhidrosis is a common and distressing problem interfering with the life of affected individuals. Currently, local surgery is the treatment of choice once conservative treatment has failed. OBJECTIVES To evaluate the clinical efficacy and safety of tumescent suction curettage (TSC) in treating axillary hyperhidrosis and to correlate it with histological markers. METHODS Thirty patients (17 females and 13 males, average age 29.9 years) underwent TSC. After tumescent anaesthesia, a suction cannula was inserted in the axilla on each side through two tiny incisions and subcutaneous tissue was removed by suction. We evaluated the clinical efficacy and complications, and in a subset of patients performed biopsies before surgery, as well as 1 month and 1 year after the operation. RESULTS In comparison with preoperative values, the sweat rate was diminished by 85% after 1 month, 71% after 6 months, 77% after 12 months and 61% after 24 months. The reduced efficacy with time was histologically correlated with an increase in the innervation, whereas the number of sweat glands continued to diminish. The majority of patients were satisfied with the operation but the satisfaction diminished with time. Patients with the highest preoperative sweat rates were the most satisfied after the intervention. CONCLUSION TSC is an effective and safe treatment for axillary hyperhidrosis. The long-term recurrence may be due to reinnervation.