Biomedical subjects

Rui Nunes

Publications and source records attributed to Rui Nunes.

5 recordsLinked to original sources

PubMed2006

Distribution of neuromuscular junctions in laryngeal and syringeal muscles in vertebrates.

Vertebrates are capable of producing a variable sound spectrum. In mammals, lissamphibia, and reptiles, the larynx is the vocal organ responsible for sound production, whereas in birds it is produced by the syrinx, an avian organ located at the base of trachea. The distribution of neuromuscular junctions responsible for the fine control of laryngeal muscle (LM) and syringeal muscle (SM), although studied with some detail in human LM, remains mostly unknown in other vertebrates. In the present study, we analyzed the distribution of motor end plates (MEPs) in LM/SM of different vertebrate classes using the histochemical detection of acetylcholinesterase: the thyroarytenoid and cricoarytenoid LM of mammal (human, rat, and rabbit) and cricoarytenoid LM of nonmammalian (frog and avian) species and the tracheobronchial SM of rooster and pigeon. In humans and frogs/avians, MEPs were distributed diffusely along, respectively, the thyroarytenoid-cricoarytenoid and the cricoarytenoid LM fibers, whereas in rats and rabbits, MEPs were concentrated in a transverse band located in the middle of thyroarytenoid and cricoarytenoid muscle fibers. In roosters and pigeons, MEPs were distributed diffusely along SM fibers. The highly diffuse MEP distribution along human thyroarytenoid and cricoarytenoid fibers indicates that these muscles can markedly change their degree of contraction, which may contribute for the large range of different sounds produced by human vocal folds. The same rationale was applied to discuss the possible functional significance of the morphological distribution of MEPs along the LM/SM of the other vertebrates analyzed.

Acetylcholine↗

PubMed2006

Deafness, genetics and dysgenics.

It has been argued by some authors that our reaction to deaf parents who choose deafness for their children ought to be compassion, not condemnation. Although I agree with the reasoning proposed I suggest that this practice could be regarded as unethical. In this article, I shall use the term "dysgenic" as a culturally imposed genetic selection not to achieve any improvement of the human person but to select genetic traits that are commonly accepted as a disabling condition by the majority of the social matrix; in short as a handicap. As in eugenics, dysgenics can be achieved in a positive and a negative way. Positive dysgenics intends to increase the overall number of people with a particular genetic trait. Marriage between deaf people or conceiving deaf children through reproductive technology are examples of positive dysgenics. Negative dysgenics can be obtained through careful prenatal or pre-implantation selection and abortion (or discarding) of normal embryos and foetuses. Only deaf children would be allowed to live. If dysgenics is seen as a programmed genetic intervention that undesirably shapes the human condition--like deliberately creating deaf or dwarf people--the professionals involved in reproductive technologies should answer the question if this should be an accepted ethical practice because the basic human right to an open future is violated.

Deafness↗

PubMed2004

Intraepithelial nerve fibers project into the lumen of the larynx.

OBJECTIVES/HYPOTHESIS: Studies on the morphology and location of the sensory receptors in the laryngeal mucosa have resulted in insufficient and sometimes conflicting data. In the present study the authors analyzed the distribution and morphology of sensory nerve plexuses and terminal fibers in the laryngeal mucosa of the rat. STUDY DESIGN: Two groups of Male Wistar rats were used in this laboratory study; the larynx of the first group were used to analyse the sensitive innervation of its epithelium, whereas the larynx of the second group (controls) were tested for the specificity of the antibodies used. METHODS: The larynges of the animals were entirely removed after perfusion, and coronal or horizontal sections were immunoprocessed for further randomized analysis of the mucosa. Primary afferents were detected by immunoreaction to two widely recognized markers of sensory nerves, calcitonin gene-related peptide and substance P, and visualized using diaminobenzidine as a chromogen. RESULTS: The nerve plexuses were more densely distributed in the dorsal half of the vocal folds and in the laryngeal aspect of the epiglottis. Dense networks of fine fibers with many varicosities en passant, immunoreactive for both calcitonin gene-related peptide and substance P, occurred in the lamina propria and along the epithelial thickness. Calcitonin gene-related peptide-immunoreactive and substance P-immunoreactive fibers extended across the epithelium and projected to the laryngeal lumen itself, reaching the space between the cilia. CONCLUSION: The projection of intraepithelial nerve fibers into the lumen of the larynx indicates that in the absence of mucus, nerve endings may be exposed and thus receive direct stimulation from airborne substances. Furthermore, it suggests that the laryngeal mucosa of the rat may constitute an experimental model for studying the direct activation or manipulation of primary afferents at the periphery and neurogenic inflammation.

Animals↗

PubMed2003

Evidence-based medicine: a new tool for resource allocation?

Evidence-Based Medicine (EBM) is defined as the conscious, and judicious use of current best evidence in making decisions about the care of individual patients. The greater the level of evidence the greater the grade of recommendation. This pioneering explicit concept of EBM is embedded in a particular view of medical practice namely the singular nature of the patient-physician relation and the commitment of the latter towards a specific goal: the treatment and the well being of his or her client. Nevertheless, in many European countries as well as in the United States, this "integration of the best evidence from systematic research with clinical expertise and patient values" appears to be re-interpreted in light of the scarcity of healthcare resources. The purpose of this paper is double. First, to claim that from an ethical perspective EBM should be a guideline to clinical practice; and second, that in specific circumstances EBM might be a useful tool in macro-allocation of healthcare resources. Methodologically the author follows Norman Daniels' theory of "democratic accountability" to justify this assumption. That is, choices in healthcare must be accountable by democratic procedures. This perspective of distributive justice is responsible for the scope and limits of healthcare services. It follows that particular entitlements to healthcare--namely expensive innovative treatments and medicines--may be fairly restricted as long as this decision is socially and democratically accountable and imposed by financial restrictions of the system. In conclusion, the implementation of EBM, as long as it limits the access to drugs and treatments of unproven scientific results is in accordance with this perspective. The use of EBM is regarded as an instrument to facilitate the access of all citizens to a reasonable level of healthcare and to promote the efficiency of the system.

Europe↗

PubMed2002

Distributive justice and the introduction of generic medicines.

INTRODUCTION: All countries face the issue of choice in healthcare. Allocation of healthcare resources is clearly associated with the concept of distributive justice and to the existence of a right to healthcare. Nevertheless, there is still the question of whether this right should include all types of healthcare services or if it should be limited to selected types. It follows that choices must be made, priorities must be set and that efficiency of healthcare services should be maximum. OBJECTIVES AND METHODS: Distributive justice aims at ensuring that everyone has access to necessary care based on the substantive ethical principles of equity and solidarity. Resource allocation is paramount in public policy particularly with regards pharmacoeconomics. The objective of this study is to determine the leading issues regarding the marketing and trade of generic medicines analysing the reasons why there are huge disparities between European countries with regards generic drugs acceptance by practitioners. RESULTS AND CONCLUSION: Distributive justice aims at ensuring that everyone has access to reasonable care based on the ethical principles of equity and solidarity. However, universality implies always choice in access and efficiency in delivery. It follows that resource allocation is instrumental in public policy particularly with regards pharmacoeconomics. The acceptance of distributive justice as a new ethical paradigm for professional ethics implies that as long as the best interest of the patient is not at stake physicians should regard the use of generic drugs as a valid instrument to promote the efficiency of the system and therefore as a way to facilitate citizen's global access to healthcare.

Drugs, Generic↗