Učinak formulacijskih parametara na oslobađanje lijeka i svojstva dvoslojnih tableta koje plutaju u želucu

Floating dosage forms of acetylsalicylic acid, used for its antithrombotic effect, were developed to prolong gastric residence time and increase bioavailability. In the two-layer tablet formulation, hydroxypropyl methylcellulose (HPMC) of high viscosity and an effervescent mixture of citric acid and sodium bicarbonate formed the floating layer. The release layer contained the drug, direct tableting agent and different types of matrix-forming polymers such as HPMC of low viscosity, sodium carboxymethylcellulose and chitosan. Tablets were prepared using a direct compression technique. The effect of formulation variables on physicochemical and floating properties and the drug release from tablets were investigated. Floating ability was dependent on the amount of effervescent agent and gel-forming polymer of the floating layer. Drug release was prolonged to 8 hours by changing the type and viscosity of the matrix-forming polymer in the drug-loading layer and all formulations showed a diffusion release mechanism.U radu su opisane plutajuće tablete acetilsalicilne kiseline za antikoagulacijsku upotrebu s produljenim zadržavanjem u želucu i većom bioraspoloživošću. Plutajući dio tih dvoslojnih tableta sadržavao je hidroksipropil metilcelulozu (HPMC) visoke viskoznosti i efervescentnu smjesu limunske kiseline i natrijevog hidrogenkarbonata. Drugi sloj sadržavao je ljekovitu tvar, sredstvo za izravno tabletiranje i različite vrste matriksnog polimera poput HPMC niske viskoznosti, natrij-karboksimetilceluloze i kitozana. Tablete su pripravljene metodom izravne kompresije. Ispitivan je utjecaj formulacijskih varijabli na fizikokemijska i plutajuća svojstva, te oslobađanje ljekovite tvari. Plutajuća svojstva ovise o količini efervescentnih tvari i gelirajućeg polimera u plutajućem sloju. Promjenom vrste i viskoznosti polimera u matriksnom sloju s lijekom produljeno je oslobađanje ljekovite tvari na 8 sati. Iz svih formulacija ljekovita tvar oslobađala se difuzijom

Calcium Homeostasis and Cone Signaling Are Regulated by Interactions between Calcium Stores and Plasma Membrane Ion Channels

Calcium is a messenger ion that controls all aspects of cone photoreceptor function, including synaptic release. The dynamic range of the cone output extends beyond the activation threshold for voltage-operated calcium entry, suggesting another calcium influx mechanism operates in cones hyperpolarized by light. We have used optical imaging and whole-cell voltage clamp to measure the contribution of store-operated Ca2+ entry (SOCE) to Ca2+ homeostasis and its role in regulation of neurotransmission at cone synapses. Mn2+ quenching of Fura-2 revealed sustained divalent cation entry in hyperpolarized cones. Ca2+ influx into cone inner segments was potentiated by hyperpolarization, facilitated by depletion of intracellular Ca2+ stores, unaffected by pharmacological manipulation of voltage-operated or cyclic nucleotide-gated Ca2+ channels and suppressed by lanthanides, 2-APB, MRS 1845 and SKF 96365. However, cation influx through store-operated channels crossed the threshold for activation of voltage-operated Ca2+ entry in a subset of cones, indicating that the operating range of inner segment signals is set by interactions between store- and voltage-operated Ca2+ channels. Exposure to MRS 1845 resulted in ∼40% reduction of light-evoked postsynaptic currents in photopic horizontal cells without affecting the light responses or voltage-operated Ca2+ currents in simultaneously recorded cones. The spatial pattern of store-operated calcium entry in cones matched immunolocalization of the store-operated sensor STIM1. These findings show that store-operated channels regulate spatial and temporal properties of Ca2+ homeostasis in vertebrate cones and demonstrate their role in generation of sustained excitatory signals across the first retinal synapse

Bridging the gap between robotic technology and health care

Although technology and computation power have become more and more present in our daily lives, we have yet to see the same tendency in robotics applied to health care. In this work we focused on the study of four distinct applications of robotic technology to health care, named Robotic Assisted Surgery, Robotics in Rehabilitation, Prosthetics and Companion Robotic Systems. We identified the main roadblocks that are limiting the progress of such applications by an extensive examination of recent reports. Based on the limitations of the practical use of current robotic technology for health care we proposed a general modularization approach for the conception and implementation of specific robotic devices. The main conclusions of this review are: (i) there is a clear need of the adaptation of robotic technology (closed loop) to the user, so that robotics can be widely accepted and used in the context of heath care; (ii) for all studied robotic technologies cost is still prohibitive and limits their wide use. The reduction of costs influences technology acceptability; thus innovation by using cheaper computer systems and sensors is relevant and should be taken into account in the implementation of robotic systems

New Insights into the Evolution of Wolbachia Infections in Filarial Nematodes Inferred from a Large Range of Screened Species

Wolbachia are intriguing symbiotic endobacteria with a peculiar host range that includes arthropods and a single nematode family, the Onchocercidae encompassing agents of filariases. This raises the question of the origin of infection in filariae. Wolbachia infect the female germline and the hypodermis. Some evidences lead to the theory that Wolbachia act as mutualist and coevolved with filariae from one infection event: their removal sterilizes female filariae; all the specimens of a positive species are infected; Wolbachia are vertically inherited; a few species lost the symbiont. However, most data on Wolbachia and filaria relationships derive from studies on few species of Onchocercinae and Dirofilariinae, from mammals.We investigated the Wolbachia distribution testing 35 filarial species, including 28 species and 7 genera and/or subgenera newly screened, using PCR, immunohistochemical staining, whole mount fluorescent analysis, and cocladogenesis analysis. (i) Among the newly screened Onchocercinae from mammals eight species harbour Wolbachia but for some of them, bacteria are absent in the hypodermis, or in variable density. (ii) Wolbachia are not detected in the pathological model Monanema martini and in 8, upon 9, species of Cercopithifilaria. (iii) Supergroup F Wolbachia is identified in two newly screened Mansonella species and in Cercopithifilaria japonica. (iv) Type F Wolbachia infect the intestinal cells and somatic female genital tract. (v) Among Oswaldofilariinae, Waltonellinae and Splendidofilariinae, from saurian, anuran and bird respectively, Wolbachia are not detected.The absence of Wolbachia in 63% of onchocercids, notably in the ancestral Oswaldofilariinae estimated 140 mya old, the diverse tissues or specimens distribution, and a recent lateral transfer in supergroup F Wolbachia, modify the current view on the role and evolution of the endosymbiont and their hosts. Further genomic analyses on some of the newly sampled species are welcomed to decipher the open questions

Lavado de manos, lavado de boca

Introducción: Durante la pandemia por COVID-19, seguimos trabajando virtualmente. Muchas plantas medicinales refuerzan el sistema inmunitario. Usamos la Matricaria Chamomilla Lineé (MC) o “Manzanilla”, en enjuagues bucales (EB), haciendo infusión de su inflorescencia, aplicando su acción antiinflamatoria y anti infecciosa, para prevenir la mayor fuente del contagio a través de las gotitas de Flügge de la saliva, acompañado del cepillado dental. Objetivos: Colaborar contra la pandemia por COVID-19, cuidando la salud de la población. Metodología: Fase I: nos reunimos con el equipo del proyecto, a través de zoom, donde nos reparten las tareas a realizar, en la escuela primaria Nº15 “General Manuel Belgrano” del barrio “Campamento” de Ensenada, que tiene jornada completa y funciona según normativas vigentes y la Unidad Sanitaria “Campamento” de Ensenada, donde atienden los consultorios de Odontología, Obstetricia, Clínica Médica y Vacunación en doble turno. Fase II: colaboramos en la confección de material didáctico para la Escuela y Unidad Sanitaria, que se envían online, para alumnos, docentes, pacientes y profesionales. Fase III: presentamos nuestra experiencia en eventos científicos, Capítulo estudiantil, para la difusión a otros alumnos. Resultados: mejoramos la salud poblacional. Conclusiones: Si informamos sobre los síntomas de la enfermedad, las normas y recomendaciones para evitar la propagación del virus SARS-CoV2,higiene, (EB), en esta población de riesgo, de esta región geográfica, estamos dando batalla a la pandemia.Facultad de Odontologí

Potassium current inhibition by nonselective cation channel-mediated sodium entry in rat pheochromocytoma (PC-12) cells.

Under physiological conditions, nonselective cation (NSC) channels mediate the entry of cations into cells, the most important being Na+ and Ca2+. In contrast to the Ca(2+)-dependent signaling mechanisms, little is known about the consequences and the spatial distribution of intracellular [Na+] elevation. In this study we demonstrate that Na+ entry, during the opening of ATP-activated NSC channels, leads to an inhibition of voltage-dependent K+ currents (IK) in cromaffin-like undifferentiated PC-12 cells. The effect was dependent on the charge carrier as well as on the density of the ATP-activated current. Extracellular alkali cations (Na+, Li+) were more efficient than NH4+ in suppressing IK. Intracellular infusion of Na+ had the same effect as Na+ influx through ATP-activated NSC channels. The inhibition of IK persisted when the total ATP-induced Na+ entry was reduced by membrane depolarization, suggesting a spatial restriction of the required Na+ accumulation. Our results indicate that NSC channels influence the function of other ion channels by changing local intracellular ion concentrations