Ultra high dilution of triiodothyronine modifies cellular apoptosis in Rana catesbeiana tadpole tail in vitro.

BACKGROUND: Ultra High Dilutions (UHD) are diluted beyond the Avogadro limit with dynamization (dilution with succussion). The process of anuran amphibian metamorphosis is controlled by thyroid hormones, including the resorption of the tadpole tail. METHODS: A randomized and blinded study was performed to investigate the influence of triiodothyronine (T3) 5·10(-24)M (10cH) on apoptosis induced by T3 100 nM in Rana catesbeiana tadpoles' tail tips, in vitro. Explants were randomized to three groups: control: no T3 in pharmacological or UHD dose; test: T3 100 nM and challenged with T3 10cH (UHD); positive control: T3 100 nM, treated with unsuccussed ethanol. The apoptotic index and the area of explants of test and control groups at the first and final day of the experiment were compared by t-test. RESULTS: There was no difference in tail tip area between test and control groups, but a significantly higher (p<0.01) index of apoptosis in explants of the test group. CONCLUSION: This data suggest that T3 10cH modifies the effect of T3 at pharmacological dose, opening new perspectives for further studies and investigation of the dose-effect curve.

Recent Trends in Nanotechnology Toward CNS Diseases: Lipid-Based Nanoparticles and Exosomes for Targeted Therapeutic Delivery.

Central nervous system (CNS) diseases constitute a set of challenging pathological conditions concerning diagnosis and therapeutics. For most of these disorders, there is a lack of early diagnosis, biomarkers to allow proper follow-up of disease progression and effective therapeutic strategies to allow a persistent cure. The poor prognosis of most CNS diseases is, therefore, a global concern, especially regarding chronic age-related neurodegenerative disorders, which are already considered problems of public health due to the increasing average of life expectancy. The difficulties associated with the treatment of CNS diseases are owed, at least in part, to very specific characteristics of the brain and spinal cord, when compared to peripheral organs. In this regard, the CNS is physically and chemically protected by the blood-brain barrier (BBB), which, while maintaining essential brain homeostasis, significantly restricts the delivery of most therapeutic agents to the brain parenchyma. On the other hand, regenerative properties of the tissue are lacking, meaning that a CNS insult resulting in neuronal death is a permanent phenomenon. Approaches for transposing the BBB aiming to treat CNS diseases, relying on specific properties of nanosystems, have been reported for therapeutic delivery to CNS without interfering with the normal function of the brain. In this chapter, we address the latest advances concerning the principles of such approaches, employing lipid-based nanoparticles and cell-produced exosomes as drug and nucleic acid delivery systems, and summarize recent example of applications in the context of neurological diseases. Major achievements obtained in preclinical studies and the trends identified by these studies are emphasized to provide new prospects for further developments in this area, thus enabling us to move from the research realm to the clinical arena.

Homeopathically prepared dilution of Rana catesbeiana thyroid glands modifies its rate of metamorphosis.

One strand of research on the scientific basis of homeopathy is based on inversion effects of dilutions and the biophysical properties of information transfer. A model developed by Endler, was the basis for the study of the influence of high-diluted solution (1:1026 part by weight) of thyroid glands on the rate of metamorphosis of the frog Rana catesbeiana from the no legged to four-legged stage. The glands were obtained from tadpoles and prepared according by (dilution and succussion). Similar pure hydroalcoholic solution (unsuccussed) was used as control. In order to identify significant differences in the frequencies of four-legged tadpoles, in homeopathic and control group, we used a chi-square goodness-of-fit test (P<0.01) and the cumulative risk for metamorphosis by Cox's Proportional Hazards model (P<0.05). The number of animals that reached the four-legged stage is generally smaller in the treated group, than in the hydroalcoholic control group. It was postulated that thyroid hormones transmitted information' specific to the molecules used to prepare the solution, even though the molarity was beyond Avogadro's number.

Sistema para a análise de desfibriladores, cardioversores e esfigmomanômetros baseado em um microcomputador / System based on a microcomputer to analyse defibrillators, cardioverters and sphygmomanometers

Este artigo descreve um sistema de baixo custo desenvolvido para realizar análise de desfibriladores cardíacos, cardioversores e esfigmomanômetros. O sistema é composto de dois módulos externos (que realizam o condicionamento do sinal dos equipamentos sob teste) e de um módulo interno que é inserido no barramento ISA de um microcomputador IBM-PC ou compatível. O módulo interno é responsável pela digitalização da forma de onda gerada pelo equipamento sob teste. Esta forma de onda é então transmitida as microcomputador, que processa e calcula os parâmetros para caracterizar o desempenha dos equipamentos sob teste. Os parâmetros calculados para o desfibrilador são: energia liberada, pico de corrente, pico de tensão e a duração do pulso. Para o cardioversor, além dos parâmetros citados, calcula-se ainda o intervalo de tempo entre a ocorrência da onda R do ECG e o pulso desfibrilatório (tempo de sincronismo). Os parâmetros calculados, juntamento com a forma de onda amostrada são apresentados na tela do microcomputador e podem ser armazenados em um arquivo texto. Para o esfigmomanômetro, calcula-se a pressão média, o erro sistemático e o desvio padrão da medida do manômetro. Exemplos de ensaios realizados com este sistema são apresentados. Os resultados dos ensaios foram comparados com os obtidos por sistemas comerciais. Estas comparações mostraram que o sistema realiza as medições com a exatidão adequada ao propósito.