994 resultados para Thyroid Gland -- drug effects


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Exogenous thyroid hormone (TH) induces premature differentiation of the zebrafish pectoral fins, which are analogous to the forelimbs of tetrapods. It accelerates the growth of the pelvic fins but not precociously. Goitrogens, which are chemical inhibitors of TH synthesis by the thyroid gland, inhibit the transition from larva to juvenile fish including the formation of scales, and pigment pattern; they stunt the growth of both pectoral and pelvic paired fins. Inhibition by goitrogens is rescued by the simultaneous addition of thyroxine. The effect of adding TH to the rearing water of the postembryonic Mexican axolotl was reinvestigated under conditions that permit continued growth and development. In addition to morphological changes that have been described, TH greatly stimulates axolotl limb growth causing the resulting larva to be proportioned as an adult in about two months. This study extends the known evolutionary relatedness of tetrapod limbs and fish fins to include the TH stimulation of salamander limb and zebrafish fin growth, and suggests that TH is required to complete the life cycle of a typical bony fish and a salamander at the same developmental stage that it controls anuran and flounder metamorphosis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Functional MRI revealed differences between children with Attention Deficit Hyperactivity Disorder (ADHD) and healthy controls in their frontal–striatal function and its modulation by methylphenidate during response inhibition. Children performed two go/no-go tasks with and without drug. ADHD children had impaired inhibitory control on both tasks. Off-drug frontal–striatal activation during response inhibition differed between ADHD and healthy children: ADHD children had greater frontal activation on one task and reduced striatal activation on the other task. Drug effects differed between ADHD and healthy children: The drug improved response inhibition in both groups on one task and only in ADHD children on the other task. The drug modulated brain activation during response inhibition on only one task: It increased frontal activation to an equal extent in both groups. In contrast, it increased striatal activation in ADHD children but reduced it in healthy children. These results suggest that ADHD is characterized by atypical frontal–striatal function and that methylphenidate affects striatal activation differently in ADHD than in healthy children.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"P620"--P. [4] of cover.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"Contract No. AT(40-1)-Gen-33."

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"In cooperation with the Agricultural Experiment Stations of Alabama, California, Florida, Georgia, Iowa, Kansas, Kentucky, Massachusetts, Michigan, Missouri, Nebraska, New Hampshire, New York (Cornell and Geneva), North Carolina, North Dakota, Oklahoma, Pennsylvania, South Carolina, South Dakota, Utah, and Wisconsin."

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We outline and evaluate competing explanations of three relationships that have consistently been found between cannabis use and the use of other illicit drugs, namely, ( 1) that cannabis use typically precedes the use of other illicit drugs; and that ( 2) the earlier cannabis is used, and ( 3) the more regularly it is used, the more likely a young person is to use other illicit drugs. We consider three major competing explanations of these patterns: ( 1) that the relationship is due to the fact that there is a shared illicit market for cannabis and other drugs which makes it more likely that other illicit drugs will be used if cannabis is used; ( 2) that they are explained by the characteristics of those who use cannabis; and ( 3) that they reflect a causal relationship in which the pharmacological effects of cannabis on brain function increase the likelihood of using other illicit drugs. These explanations are evaluated in the light of evidence from longitudinal epidemiological studies, simulation studies, discordant twin studies and animal studies. The available evidence indicates that the association reflects in part but is not wholly explained by: ( 1) the selective recruitment to heavy cannabis use of persons with pre-existing traits ( that may be in part genetic) that predispose to the use of a variety of different drugs; ( 2) the affiliation of cannabis users with drug using peers in settings that provide more opportunities to use other illicit drugs at an earlier age; ( 3) supported by socialisation into an illicit drug subculture with favourable attitudes towards the use of other illicit drugs. Animal studies have raised the possibility that regular cannabis use may have pharmacological effects on brain function that increase the likelihood of using other drugs. We conclude with suggestions for the type of research studies that will enable a decision to be made about the relative contributions that social context, individual characteristics, and drug effects make to the relationship between cannabis use and the use of other drugs.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A field-applicable assay for testing anthelmintic sensitivity is required to monitor for anthelmintic resistance. We undertook a study to evaluate the ability of three in vitro assay systems to define drug sensitivity of clinical isolates of the human hookworm parasite Necator americanus recovered from children resident in a village in Madang Province, Papua New Guinea. The assays entailed observation of drug effects on egg hatch (EHA), larval development (LDA), and motility of infective stage larvae (LMA). The egg hatch assay proved the best method for assessing the response to benzimidazole anthelmintics, while the larval motility assay was suitable for assessing the response to ivermectin. The performance of the larval development assay was unsatisfactory on account of interference caused by contaminating bacteria. A simple protocol was developed whereby stool samples were subdivided and used for immediate egg recovery, as well as for faecal culture, in order to provide eggs and infective larvae, respectively, for use in the egg hatch assay and larval motility assay systems. While the assays proved effective in quantifying drug sensitivity in larvae of the drug-susceptible hookworms examined in this study, their ability to indicate drug resistance in larval or adult hookworms remains to be determined. (c) 2005 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction. Thyroid cancer is the most common endocrine malignancy and accounts for almost 1% of human cancer. It is well known that the majority of cases occur in women in the middle decades of life. Thyroid cancer is a relatively rare disease; on the other hand clinically apparent thyroid nodules are present in 4-7% of the adult population. Most thyroid nodules are not malignant, with reported malignancy rates from 3-12%. It is important for the surgeon to know beforehand the diagnosis of malignancy, in order to perform a more radical operation on the thyroid gland. Patients and Methods. In our study we have analyzed the preoperative clinical data of 84 patients operated in the First Clinic of General Surgery, UHC “Mother Theresa” in Tirana; all with a positive histopathologic diagnosis of thyroid cancer. The data comprised age, sex, age distribution, blood group, time-lapse from the first endocrinologic visit, clinical examination, signs and symptoms, imaging, functional tests, preoperative FNA, admission diagnosis, associated diseases and preoperative treatment. Results. From the study emerged that only 9,3% of these patients were diagnosed preoperatively as thyroid cancer. Another related problem is the low percentage of preoperative FNA – only 22%. Among the signs and symptoms related to thyroid cancer we found that 40 and 33% of these patient presented dyspnea and dysphagia, respectively. The physical examination revealed apparent nodular growth of the thyroid gland in 81% and nodular hard consistency in 79% of cases. The proper endocrinologist consultation lacked in 23% of cases. Conclusion. In our opinion, close collaboration between endocrinologists and surgeons in a multidisciplinary frame is the key to correct preoperative thyroid cancer diagnosis and optimal treatment.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction. Ectopic thyroid tissue can be found in many sites, including the tongue, thyroglossal duct, mediastinum, trachea, lung, aorta and abdomen. Ectopic thyroid tissue may also be involved in the same processes as normal, orthotopic thyroid gland. These processes include tumors, inflammation and hyperplasia. The appearance of such tissue in rare locations may lead to diagnostic and therapeutic dilemmas. Case report. We report a rare case of ectopic thyroglossal thyroid carcinoma in a 63-year-old Caucasian male with a normal orthotopic thyroid gland. Conclusion. Although 99% of thyroid cancers develop within the thyroid itself, in rare cases a carcinoma can arise in ectopic thyroid tissue located in the neck or in other areas of the body. Though rare, the possibility of an ectopic thyroid carcinoma must always be considered by the surgeon in cases of a pathological mass in the neck.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação de Mestrado, Ciências Biomédicas, 28 de Junho de 2016, Universidade dos Açores.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We study the problem of detecting sentences describing adverse drug reactions (ADRs) and frame the problem as binary classification. We investigate different neural network (NN) architectures for ADR classification. In particular, we propose two new neural network models, Convolutional Recurrent Neural Network (CRNN) by concatenating convolutional neural networks with recurrent neural networks, and Convolutional Neural Network with Attention (CNNA) by adding attention weights into convolutional neural networks. We evaluate various NN architectures on a Twitter dataset containing informal language and an Adverse Drug Effects (ADE) dataset constructed by sampling from MEDLINE case reports. Experimental results show that all the NN architectures outperform the traditional maximum entropy classifiers trained from n-grams with different weighting strategies considerably on both datasets. On the Twitter dataset, all the NN architectures perform similarly. But on the ADE dataset, CNN performs better than other more complex CNN variants. Nevertheless, CNNA allows the visualisation of attention weights of words when making classification decisions and hence is more appropriate for the extraction of word subsequences describing ADRs.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Advanced cell cultures are developing rapidly in biomedical research. Nowadays, various approaches and technologies are being used, however, these culturing systems present limitations from increasing complexity, requiring high costs, and not easily customization. We present two versatile and cost-effective methods for developing culturing systems that integrate 3D cell culture and microfluidic platforms. Firstly, for drug screening applications, many high-quality cell spheres of homogeneous size and shape are required. Conventional approaches usually have a dearth of control over the size and geometry of cell spheres and require sample collection and manipulation. To overcome this difficulty, in this study, hundreds of spheroids of several cell lines were generated using multi-well plates that housed our microdevices. Tumor spheroids grow at a uniform rate (in scaffolded or scaffold-free environments) and can be harvested at will. Microscopy imaging are done in real time during or after the culture. After in situ immunostaining, fluorescence imaging can be conducted while keeping the spatial distribution of spheroids in the microwells. Drug effects were successfully observed through viability, growth, and morphologic investigations. Also, we fabricated a microfluidic device suitable for directed and selective cell culture treatments. The microfluidic device was used to reproduce and confirm in vitro investigations carried out using normal culture methods, using a microglia cell line. The device layout and the syringe pump system, entirely designed in our lab, successfully allowed culture growth and medium flow regulation. Solution flows can be finely controlled, allowing treatments and immunofluorescence in one single chamber selectively. To conclude, we propose the development of two culturing platforms (microstructured well devices and in-flow microfluidic chip), which are the result of separate scientific investigations but have the primary goal of performing treatments in a reproducible manner. Our devices shall improve future studies on drug exposure testing, representing adjustable and versatile cell culture systems.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

There are many diseases that affect the thyroid gland, and among them are carcinoma. Thyroid cancer is the most common endocrine neoplasm and the second most frequent cancer in the 0-49 age group. This thesis deals with two studies I conducted during my PhD. The first concerns the development of a Deep Learning model to be able to assist the pathologist in screening of thyroid cytology smears. This tool created in collaboration with Prof. Diciotti, affiliated with the DEI-UNIBO "Guglielmo Marconi" Department of Electrical Energy and Information Engineering, has an important clinical implication in that it allows patients to be stratified between those who should undergo surgery and those who should not. The second concerns the application of spatial transcriptomics on well-differentiated thyroid carcinomas to better understand their invasion mechanisms and thus to better comprehend which genes may be involved in the proliferation of these tumors. This project specifically was made possible through a fruitful collaboration with the Gustave Roussy Institute in Paris. Studying thyroid carcinoma deeply is essential to improve patient care, increase survival rates, and enhance the overall understanding of this prevalent cancer. It can lead to more effective prevention, early detection, and treatment strategies that benefit both patients and the healthcare system.