Anticipating hyperthermic efficiency of magnetic colloids using a semi-empirical model: a tool to help medical decisions.

Magnetic hyperthermia, a modality that uses radio frequency heating assisted with single-domain magnetic nanoparticles, is becoming established as a powerful oncological therapy. Much improvement in nanomaterials development, to enhance their heating efficiency by tuning the magnetic colloidal properties, has been achieved. However, methodological standardization to accurately and univocally determine the colloidal properties required to numerically reproduce a specific heating efficiency using analytical expressions still holds. Thus, anticipating the hyperthermic performances of magnetic colloids entails high complexity due to polydispersity, aggregation and dipolar interactions always present in real materials to a greater or lesser degree. Here, by numerically simulating the experimental results and using real biomedical aqueous colloids, we analyse and compare several approaches to reproduce experimental specific absorption rate values. Then, we show that the relaxation time, determined using a representative mean activation energy consistently derived from four independent experiments accurately reproduces experimental heating efficiencies. Moreover, the so-derived relaxation time can be used to extrapolate the heating performance of the magnetic nanoparticles to the other field conditions within the framework of the linear response theory. We thus present a practical tool that may truly aid the design of medical decisions.

Amelogénesis imperfecta: a propósito de un caso / Amelogenesis imperfecta: a case report

Como Amelogénesis Imperfecta (AI) es denominado un grupo de desórdenes hereditarios, clínica y genéticamente heterogéneos, caracterizados por alteraciones en el esmalte dentario. Pueden presentarse acompañados de otras alteraciones en la cavidad oral o fuera de ella. Genéticamente la AI es transmitida ligada al cromosoma X, o de forma autosómica dominante o recesiva. Se clasifica según el fenotipo, el mecanismo de desarrollo y la forma de herencia en cuatro tipos principales: Hipoplásica, Hipocalcificada, Hipomadura e Hipomadura-Hipoplásica con taurodontismo. Objetivo: Revisar aspectos diagnósticos y de tratamiento y describir el manejo terapéutico de una adolescente con Amelogénesis Imperfecta, para restablecer la estética y función a través de un tratamiento conservador de transición. Presentación del caso: Paciente de género femenino, 12 años de edad, consulta por sensibilidad dentaria a los cambios térmicos e insatisfacción con su apariencia. Todos sus dientes presentan un esmalte opaco con manchas amarillo café, sus primeros molares están destruidos debido a fracturas post-eruptivas. Clínica y radiográficamente se diagnostica Amelogénesis Imperfecta de tipo hipomadura, con mordida abierta anterior y gingivitis asociada a placa bacteriana. La planificación de su tratamiento incluye una fase preventiva simultánea a la fase restauradora con carillas de resinas compuestas en incisivos y caninos y coronas metálicas en los primeros molares permanentes. Conclusión: Un diagnóstico oportuno y un tratamiento de transición adecuado, es fundamental para mantener y devolver la estética y función al paciente adolescente afectado con esta condición, contribuyendo a la vez a mejorar su calidad de vida, en espera de la rehabilitación definitiva

Amelogenesis Imperfecta (AI) is the name of a group of inherited disorders, clinically and genetically heterogeneous, characterized by alterations in the enamel. It may be accompanied by other changes in the oral cavity or elsewhere. This condition is transmitted genetically X-linked, or as an autosomal dominant or recessive character. Classified according to phenotype, pathogenesis, and mode of inheritance in four main types: Hypoplastic, Hypocalcified, Hypomaturated and Hypomaturated-Hypoplastic with taurodontism. Objective: To review the diagnostic and treatment and describe the therapeutic management of a teenager with Amelogenesis Imperfecta, to restore aesthetics and function through a transitional conservative treatment. Case Presentation: A female patient, aged 12, referring dental temperature-sensitive changes and unsatisfaction with their appearance. All teeth have a yellow opaque enamel with brown spots, the first molars are destroyed due to post-eruptive fractures. Clinically and radiographically diagnosed type Hypomaturated Amelogenesis Imperfecta with anterior open bite and plaque-associated gingivitis. Planning her treatment includes preventive stage simultaneous phase composite veneer restorations in incisors and canines and metal crowns on the first permanent molars. Conclusion: An early diagnosis and treatment of transition, it is essential to maintain and restore aesthetics and function to the adolescent patient afflicted with this condition, contributing both to improve their quality of life, pending the final restoration

Effect of different sequential and two-step culture systems on the development, quality, and RNA expression profile of bovine blastocysts produced in vitro.

In the present study, we examined the effect of two-step and sequential culture systems on the development, quality, and gene expression profile of bovine embryos generated by in vitro fertilization. Presumptive zygotes were randomly allocated to four culture treatments: (1) KSOM + 0.4% BSA for 3 days, and then KSOM + 5% FBS to day 7 (K-K/FBS); (2) KSOM + 0.1% BSA for 3 days, and then SOF + 5% FBS to day 7 (K-S/FBS); (3) KSOM + 0.1% BSA for 3 days, and then SOF + 0.8% BSA to day 7 (K-S/BSA); and (4) KSOM + 0.4% BSA for 3 days, and then KSOM + 0.8% BSA to day 7 (K-K/BSA). Culture medium had no effect on cleavage rate. However, a significant difference (P < 0.01) was observed with the two-step culture systems, yielding higher rate of blastocysts (37 and 32% for K-K/FBS and K-K/BSA, respectively) compared to sequential culture systems (26 and 28% for K-S/FBS and K-S/BSA, respectively). Embryos cultured in sequential K-S/FBS developed slowly, had a lower hatching rate, fewer cells, and a higher apoptosis rate compared to other treatments. Gene expression analysis showed alterations of DNMT1, OCT-4, and SOD2 in embryos cultured in sequential K-S/FBS and SOD1 in embryos cultured in two-step K-K/BSA. In conclusion, in vitro culture systems may have an impact not just in the developmental potential and quality of the generated embryos but also in the gene expression profile, which suggests that changes in the culture medium composition can modulate global gene expression.

Glutamine Involvement in Nitrogen Control of Gibberellic Acid Production in Gibberella fujikuroi.

When the fungus Gibberella fujikuroi ATCC 12616 was grown in fermentor cultures, both intracellular kaurene biosynthetic activities and extracellular GA(3) accumulation reached high levels when exogenous nitrogen was depleted in the culture. Similar patterns were exhibited by several nonrelated enzymatic activities, such as formamidase and urease, suggesting that all are subject to nitrogen regulation. The behavior of the enzymes involved in nitrogen assimilation (glutamine synthetase, glutamate dehydrogenase, and glutamate synthase) during fungal growth in different nitrogen sources suggests that glutamine is the final product of nitrogen assimilation in G. fujikuroi. When ammonium or glutamine was added to hormone-producing cultures, extracellular GA(3) did not accumulate. However, when the conversion of ammonium into glutamine was inhibited by L-methionine-DL-sulfoximine, only glutamine maintained this effect. These results suggest that glutamine may well be the metabolite effector in nitrogen repression of GA(3) synthesis, as well as in other nonrelated enzymatic activities in G. fujikuroi.