Organ xenotransplantation acceptance in veterinary students: A multicentric opinion study in Spain

BACKGROUND

The shortage of available transplant organs has made it necessary to search for alternatives, one of which is xenotransplantation. However, the use of animal organs could face rejection from society and the personnel involved in its implementation.

OBJECTIVES

(a) to analyze the attitudes of Veterinary Degree students in six Spanish Universities towards xenotransplantation; and (b) to determine the factors that affect its acceptance.

METHODS

Of the 2815 students surveyed in the degree program, 2683 valid surveys were obtained. Attitudes towards organ xenotransplantation were evaluated using a validated questionnaire of organ donation.

RESULTS

If xenotransplantation was confirmed as a clinical reality, 93% (n = 2493) of those surveyed would accept a xenotransplanted organ, whilst 7% would not. If the results of xenotransplantation were worse than those obtained with human donors and it entailed more risk, 12% (n = 318) would be in favor. 56% (n = 1497) of the students would accept a xenotransplantation provisionally pending the arrival of a human organ. Attitudes towards xenotransplantation were affected by the academic year in which a student was studying, with more favorable attitudes among students in the last year (88% in first year vs. 95% in fifth year; p < .001). More favorable attitudes are also observed depending on the attitude they have towards organ transplantation, with those students being more in favor of donating their organs when they die (94% vs. 88%; p < .001).

CONCLUSION

Veterinary students would have a very favorable attitude toward xenotransplantation if these animal organs functioned as well as human organs. Therefore, these students could play an important role in the future promotion of this technique.

Advantages of using relevant nearly optimal solutions in multi-objective tuning of robust controllers

This paper presents a new approach for the multiobjective optimal design of robust controllers in systems with stochastic parametric uncertainty. Traditionally, uncertainty is incorporated into the optimization process. However, this can generate two problems: (1) low performance in the nominal scenario; and (2) high computational cost. For the first point, it is possible to ensure that the controllers produce an acceptable performance for the nominal scenario in exchange for being lightly robust. For the second point, the methodology proposed in this work reduces the computational cost significantly. This approach addresses uncertainty by analyzing the robustness of optimal and nearly optimal controllers in the nominal scenario. The methodology guarantees obtaining controllers that are similar/neighboring to lightly robust controllers. Two examples of controller design are shown: one for a linear model and another for a nonlinear model. Both examples demonstrate the usefulness of the proposed new approach.

[Comparative analysis of Grade I vs Grade II intracranial Meningiomas in a retrospective series of 63 patients]

Objective

We aimed to demonstrate the differences between grade I and II (OMS classification) of intracranial meningiomas. We evaluate their location, Simpson resection grade, re-operations rate, adjuvant treatment and patient outcomes.

Methods

We conduct a retrospective review of Sixty- three clinical records of patients who were diagnosed with meningiomas grade I and II (OMS) between 2009-2015 and received surgical treatment at our Hospital. We evaluated different variables such as age, sex, histological type, Simpson grade resection, location, symptoms, radiotherapy, follow-up, mortality rate and patient outcome. The main aim was to establish the differences between these intracranial tumors.

Results

A total of sixty-three patients diagnosed with meningiomas and received surgical treatment; fifty-one were grade I and thirteen with grade II. There were no differences in the rate between man and women. The average age for both types of meningiomas was 57 years old. The typical meningiomas were located in 55% of the cases outside the cranial base vs. 91.6% of the atypical meningiomas (P = 0.03). Typical meningioma had a Simpson resection grade of I, II and III in 74.5% against 58.3% of the atypical (P = 0.2). The atypical meningioma in 33% had more than one-stage surgery vs. 9.8% of the typical (P = 0.03). The patients with a typical meningioma showed a good outcome in 86.2% vs. 53.8 of the grade II (P = 0, 01). The typical meningiomas showed a good outcome in 82.2% of the cases vs. 53.8% of the atypical. The grade II meningiomas received adjuvant treatment in 33.3%, while the grade I only 1.9%.

Conclusions

The atypical intracranial meningiomas have a worse outcome compared with the typical kind and a higher incidence of re-operations. These tumors have a preference for a location outside the cranial base. Concluding that the location could be a risk factor.

Optimized sound diffusers based on sonic crystals using a multiobjective evolutionary algorithm

Sonic crystals have been demonstrated to be good candidates to substitute for conventional diffusers in order to overcome the need for extremely thick structures when low frequencies have to be scattered, however, their performance is limited to a narrow band. In this work, multiobjective evolutionary algorithms are used to extend the bandwidth to the whole low frequency range. The results show that diffusion can be significantly increased. Several cost functions are considered in the paper, on the one hand to illustrate the flexibility of the optimization and on the other hand to demonstrate the problems associated with the use of certain cost functions. A study of the robustness of the optimized diffusers is also presented, introducing a parameter that can help to choose among the best candidates. Finally, the advantages of the use of multiobjective optimization in comparison with conventional optimizations are discussed.

Hole distribution in phononic crystals: design and optimization

An exhaustive study has been made into the potential improvement in attenuation and focusing of phononic crystal arrays resulting from the deliberate creation of vacancies. Use is made of a stochastic search algorithm based on evolutionary algorithms called the epsilon variable multi-objective genetic algorithm which, in conjunction with the application of multiple scattering theory, enables the design of devices for effectively controlling sound waves. Several parameters are analyzed, including the symmetries used in the distribution of holes and the optimum number of holes. The validity and utility of the general rules obtained have been confirmed experimentally.

[Asymptomatic bilateral pharyngocele]

The diverticula of the lateral wall of the pharynx are called pharyngoceles. We present a case of a 71-year old male in whom we discovered, by chance, a bilateral pharyngocele. Given their scarcity, we review the characteristics of the process, highlighting the relevance of the oesophagopharingeal barium swallow. Finally, we describe two possible anatomical locations of the herniated sac.

[Study of renal function after the administration of a low-osmolarity iodized contrast medium. Prospective study]

We analysed the development of various kidney function parameters in 40 patients on whom an intravenous urography had been carried out with a non-ionic contrast medium of low osmolarity (iohexol). No patient displayed prior renal insufficiency (serum creatinine 0.4-2mg/dl). Twenty-four hours after injection of the iodized contrast no significant variations in urea blood concentrations, creatinine, sodium or uric acid appeared. As a result of the urography an increase in urine osmolarity and a decrease in fractional sodium excretion took place.

IN CONCLUSION

in patients without renal insufficiency intravenous urography with iohexol does not give rise to a significant alteration in the renal excretory function.