Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

Ultrastructure of “putative” neurotransmitter sites in Schistosoms mansoni Miracida

1990 ◽  
Vol 48 (3) ◽  
pp. 424-425
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tung Pan
Keyword(s):  
Developing Countries ◽  
World Wide ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
Infective Stage ◽  
The Social ◽  
Social And Economic Development ◽  
The World ◽  
Basic Biology

Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is world wide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease, and thus, the number of infections are increasing.Our knowledge of the basic biology of the parasite causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes.

Structure of “Sensory” Surface Nerve Endings in Schistosoma Mansoni Miracidia

1988 ◽  
Vol 46 ◽  
pp. 272-273
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tung Pan
Keyword(s):  
Developing Countries ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
Infective Stage ◽  
The Social ◽  
Social And Economic Development ◽  
The World ◽  
Basic Biology ◽  
Sensory Surface

Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease, and thus, the number of infections are increasing.Our knowledge of the basic biology of the parasite causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes.

scholarly journals Functional Diversity of the Schistosoma mansoni Tyrosine Kinases

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Lívia G. A. Avelar ◽  
Laila A. Nahum ◽  
Luiza F. Andrade ◽  
Guilherme Oliveira
Keyword(s):  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Tyrosine Kinases ◽  
Large Body ◽  
Protein Domain ◽  
Complex Life Cycle ◽  
Main Process ◽  
Parasite Life Cycle ◽  
Causative Agents

Schistosoma mansoni, one of the causative agents of schistosomiasis, has a complex life cycle infecting over 200 million people worldwide. Such a successful and prolific parasite life cycle has been shown to be dependent on the adaptive interaction between the parasite and hosts. Tyrosine kinases (TKs) play a key role in signaling pathways as demonstrated by a large body of experimental work in eukaryotes. Furthermore, comparative genomics have allowed the identification of TK homologs and provided insights into the functional role of TKs in several biological systems. Finally, TK structural biology has provided a rational basis for obtaining selective inhibitors directed to the treatment of human diseases. This paper covers the important aspects of the phospho-tyrosine signaling network in S. mansoni, Caenorhabditis elegans, and humans, the main process of functional diversification of TKs, that is, protein-domain shuffling, and also discusses TKs as targets for the development of new anti-schistosome drugs.

scholarly journals Transplantation of schistosome sporocysts between host snails: A video guide

2018 ◽  
Vol 3 ◽  
pp. 3 ◽  
Author(s):  
Gabriel Mouahid ◽  
Anne Rognon ◽  
Ronaldo de Carvalho Augusto ◽  
Patrick Driguez ◽  
Kathy Geyer ◽  
...  
Keyword(s):  
Life Cycle ◽  
Ex Vivo ◽  
Freshwater Snail ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Parasitic Disease ◽  
Video Instruction ◽  
Different Types ◽  
Causative Agents ◽  
Technical Basis

Schistosomiasis is an important parasitic disease, touching roughly 200 million people worldwide. The causative agents are different Schistosoma species. Schistosomes have a complex life cycle, with a freshwater snail as intermediate host. After infection, sporocysts develop inside the snail host and give rise to human dwelling larvae. We present here a detailed step-by-step video instruction in English, French, Spanish and Portuguese that shows how these sporocysts can be manipulated and transferred from one snail to another. This procedure provides a technical basis for different types of ex vivo modifications, such as those used in functional genomics studies.

scholarly journals A DnaK Homolog in Myxococcus xanthus Is Involved in Social Motility and Fruiting Body Formation

1998 ◽  
Vol 180 (2) ◽  
pp. 218-224 ◽  
Author(s):  
Zhaomin Yang ◽  
Yongzhi Geng ◽  
Wenyuan Shi
Keyword(s):  
Life Cycle ◽  
Myxococcus Xanthus ◽  
Complex Life Cycle ◽  
Phenotypic Characterization ◽  
Fruiting Body Formation ◽  
Gram Negative ◽  
Body Formation ◽  
The Social ◽  
Cellular Aggregation ◽  
Social Motility

ABSTRACT Myxococcus xanthus is a gram-negative soil bacterium which exhibits a complex life cycle and social behavior. In this study, two developmental mutants of M. xanthus were isolated through Tn5 transposon mutagenesis. The mutants were found to be defective in cellular aggregation as well as in sporulation. Further phenotypic characterization indicated that the mutants were defective in social motility but normal in directed cell movements. Both mutations were cloned by a transposon-tagging method. Sequence analysis indicated that both insertions occurred in the same gene, which encodes a homolog of DnaK. Unlike the dnaK genes in other bacteria, this M. xanthus homolog appears not to be regulated by temperature or heat shock and is constitutively expressed during vegetative growth and under starvation. The defects of the mutants indicate that this DnaK homolog is important for the social motility and development of M. xanthus.

Schistosoma mansoni male–female interactions

2004 ◽  
Vol 82 (2) ◽  
pp. 357-374 ◽  
Author(s):  
Philip T LoVerde ◽  
Edward G Niles ◽  
Ahmed Osman ◽  
Wenjie Wu
Keyword(s):  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Egg Production ◽  
Reproductive Development ◽  
Host Factors ◽  
Complex Life Cycle ◽  
Morphological Observation ◽  
Male Worm ◽  
Male And Female

Schistosome parasites are muticellular eucaryotic organisms with a complex life cycle that involves mammalian and snail hosts. Unlike other trematode parasites, schistosomes (along with the Didymozoidae) have evolved separate sexes or dioecy. Sex is determined by a chromosomal mechanism. The dioecious state created an opportunity for the sexes to play a role in schistosome evolution that has resulted in an interesting interplay between the sexes. The classical observation, made more than 50 years ago, is that female schistosomes do not develop unless a male worm is present. Studies up through the 1990s focused on dissecting the role of the sexes in mate attraction, mate choice, mating behavior, female growth, female reproductive development, egg production, and other sex-evolved functions. In the mid-1980s, studies began to address the molecular events of male–female interactions. The classic morphological observation that female schistosomes do not complete reproductive development unless a male worm is present has been redefined in molecular terms. The male by an unknown mechanism transduces a signal that regulates female gene expression in a stage-, tissue-, and temporal-specific manner. A number of female-specific genes have been identified, along with signaling pathways and nuclear receptors, that play a role in female reproductive development. In addition, a number of host factors such as cytokines have also been demonstrated to affect adult male and female development and egg production. This review focuses on the biological interactions of the male and female schistosome and the role of parasite and host factors in these interactions as they contribute to the life cycle of Schistosoma mansoni.

Socio-cultural Resource for Kazakhstan Modernization

2012 ◽  
pp. 74-82 ◽  
Author(s):  
A. Stavinskaya ◽  
E. Nikishina
Keyword(s):  
Social Capital ◽  
Cultural Capital ◽  
Competitive Advantages ◽  
Institutional Reforms ◽  
Cultural Resource ◽  
Bonding Social Capital ◽  
Social And Cultural Capital ◽  
The Social ◽  
Social And Economic Development ◽  
Cultural Features

The opportunities of the competitive advantages use of the social and cultural capital for pro-modernization institutional reforms in Kazakhstan are considered in the article. Based on a number of sociological surveys national-specific features of the cultural capital are marked, which can encourage the country's social and economic development: bonding social capital, propensity for taking executive positions (not ordinary), mobility and adaptability (characteristic for nomad cultures), high value of education. The analysis shows the resources of the productive use of these socio-cultural features.

On the Issue of Progressive or Proportional Taxation of Personal Incomes

2018 ◽  
Vol 11 (3) ◽  
pp. 114-120
Author(s):  
D. G. Chernik
Keyword(s):  
Income Tax ◽  
Personal Income ◽  
Personal Income Tax ◽  
The Social ◽  
Social And Economic Development ◽  
The Subject ◽  
Discrete Measures ◽  
Personal Income Taxation ◽  
Personal Taxation ◽  
Personal Incomes

The subject of the research is the procedure for personal income taxation. The purpose of the workwas to determine which personal taxation regime is more justified: progressive or proportional. The paperprovides the reasons for the transition from the progressive to the proportional tax. The risks and possibilities of transition to the progressive scale are analyzed. It is concluded that in order to achieve social justice and improve the welfare of the majority of peoplerather thana very small part of them, it is necessary to adopt a set of economic, fiscal and administrative measures aimed at solving a single task — ensuring the social and economic development of Russia. Discrete measures, such as the introduction of the progressive personal income tax will not lead to desired results. Moreover, the progressive tax cannot be introduced unlessit is ruled by law that large spendings of citizens must correspond to their incomes.

Sign in / Sign up

Export Citation Format

Share Document