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Parasitology,
2000]
This detailed review of the published studies underlying ivermectin's recent registration for use in lymphatic filariasis (LF) demonstrates the drug's single-dose efficacy (over the range of 20-400 microg/kg) in clearing microfilaraemia associated with both Wuchereria bancrofti and Brugia malayi infections of humans. While doses as low as 20 microg/kg could effect transient microfilarial (mf) clearance, higher dosages induced greater and more sustained mf reduction. The single dose of 400 microg/kg yielded maximal responses, but a number of practical considerations suggest that either 400 microg/kg or 200 microg/kg doses would be acceptable for use in LF control programmes. Associated safety assessments indicate that adverse events, which occur commonly following treatment of microfilaraemic individuals, develop not because of drug toxicity but because of host inflammatory responses to dying microfilariae killed by the ivermectin treatment. Ivermectin is, therefore, a highly effective and generally well tolerated microfilaricide that may soon become an essential component of many public health initiatives to interrupt transmission of lymphatic filarial infection in an effort to eliminate LF globally.
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The New York Times,
1997]
His tall figure bent over a computer screen in his laboratory at the Massachusetts General Hospital, Dr. Gary Ruvkun rummages through a distant genetic data base for matches to a gene he believes is involved in diabetes. ?You learn how to read these as they are ratcheting by,? he says, while lines of data streak up his screen. ?I think MTV is good training.?
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Acta Leiden,
1990]
Community trials were started to address questions concerning the safety of ivermectin during large scale treatment, its potential for transmission control, its effect in preventing ocular onchocercal disease, its acceptability and the organization of large scale treatment. A summary is presented of the major, latest results on the short-term epidemiological impact of large scale ivermectin treatment, as observed in eight community trials undertaken in the Onchocerciasis Control Programme in West Africa (OCP). Ivermectin treatment resulted in a 96%-99% reduction in the mean load of microfilariae (mf) in the skin in treated patients. The subsequent mf-repopulation of the skin was faster than in the clinical trials and after 12 months the mean loads had returned to more than 40% of the pre-treatment load. Ocular mf loads were also greatly reduced and a post-treatment regression of early lesions of the anterior segment of the eye was observed. The transmission of Onchocerca volvulus was reduced by some 60% during the first year after treatment in one trial but no additional reduction was observed after the second treatment round. These results, and other recent research findings, have been used to quantify an epidemiological model for the transmission and control of onchocerciasis. Preliminary results of computer simulations of the predicted long-term epidemiological impact of large scale ivermectin treatment indicate that ivermectin treatment may play a very important role in disease control but that it is unlikely to become a practical tool for transmission control in endemic foci. Ivermectin treatment appears to be the most appropriate method for control of recrudescence of infection in an area where the parasite reservoir has been virtually eliminated by vector control, such as in the core area of the OCP.
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Mechanisms of Ageing & Development,
2005]
Recent results indicate that the longevity of both invertebrates and vertebrates can be altered through genetic manipulation and pharmacological intervention. Most of these interventions involve alterations of one or more of the following: insulin/IGF-I signaling pathway, caloric intake, stress resistance and nuclear structure. How longevity regulation relates to aging per se is less clear, but longevity increases are usually accompanied by extended periods of good health. How these results will translate to primate aging and longevity remains to be shown.
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Curr Opin Genet Dev,
1997]
Caenorhabditis elegans will be the first multicellular animal to have its entire genome sequenced. This is not just good news for those currently working in the field, but also for those trying to understand the biology of more complex animals, including humans. C elegans is a relatively simple animal that is amenable to studies of genetics and developmental processes that are common to all animals, making this an attractive model in which to study basic processes that are altered in human disease. Powerful forward and reverse genetics mean that virtually any gene of interest can be studied at the functional level.
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Trends Genet,
1995]
The many features that have made the hermaphroditic nematode Caenorhabditis elegans a good model system for studying development have also attracted investigators to the study of meiosis. Genetic analysis suggests that in C. elegans there are two types of chromosomal sites required for proper meiotic function. The first is needed early in meiosis for recombination and segregation. The second is involved in the mechanisms that establish the normal frequency and distribution of exchange. Genes whose products may interact with these sites have been identified by mutant analysis. Study of these mutations in the nematode is enhancing our general understanding of meiotic
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Taylor DW, Bain O, Adjei O, Trees AJ, Hoerauf A, Hoffmann WH, Wanji S, Makepeace BL, Allen JE, Schulz-Key H, Tanya VN
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PLoS Negl Trop Dis,
2008]
River blindness is a seriously debilitating disease caused by the filarial parasite Onchocerca volvulus, which infects millions in Africa as well as in South and Central America. Research has been hampered by a lack of good animal models, as the parasite can only develop fully in humans and some primates. This review highlights the development of two animal model systems that have allowed significant advances in recent years and hold promise for the future. Experimental findings with Litomosoides sigmodontis in mice and Onchocerca ochengi in cattle are placed in the context of how these models can advance our ability to control the human disease.
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Trends Cell Biol,
2016]
Most current research in cell biology uses just a handful of model systems including yeast, Arabidopsis, Drosophila, Caenorhabditis elegans, zebrafish, mouse, and cultured mammalian cells. And for good reason - for many biological questions, the best system for the question is likely to be found among these models. However, in some cases, and particularly as the questions that engage scientists broaden, the best system for a question may be a little-studied organism. Modern research tools are facilitating a renaissance for unusual and interesting organisms as emerging model systems. As a result, we predict that an ever-expanding breadth of model systems may be a hallmark of future cell biology.
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Mol Cell Endocrinol,
2009]
In recent years, there has been significant growth in our understanding of the regulation of longevity. The most notable change is the identification and detailed description of a number of molecular pathways modulating the rate of aging. A good portion of this new data has come from studies using the genetic model organism Caenorhabditis elegans. In this review, we provide an overview of physiological systems that are involved in the modulation of aging in C. elegans, then discuss the known endocrine signaling systems that are likely to couple these systems together. Finally, we present a working model describing how aging may be regulated as a coordinated system, communicating through endocrine signals.
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Methods Cell Biol,
1995]
Sequence analysis of cosmids from C. elegans and other organisms currently is best done using the random or "shotgun" strategy (Wilson et al., 1994). After shearing by sonication, DNA is used to prepare M13 subclone libraries which provide good coverage and high-quality sequence data. The subclones are assembled and the data edited using software tools developed especially for C. elegans genomic sequencing. These same tools facilitate much of the subsequent work to complete both strands of the sequence and resolve any remaining ambiguities. Analysis of the finished sequence is then accomplished using several additional computer tools including Genefinder and ACeDB. Taken together, these methods and tools provide a powerful means for genome analysis in the nematode.