ABSTRACT
Echinostomatidae (Trematoda) is the largest family within the class Trematoda. Members of this family have been studied for many years in relation to their utility as basic research models in biodiversity and systematics and also as experimental models in parasitology since they offer many advantages. Echinostomes have contributed significantly to numerous developments in many areas studied by parasitologists and experimental biologists. In this review, we examine the history of the echinostomebased studies from the beginnings to the present. For this purpose, we have divided the history of echinostomes into four periods (i.e. 18(th) and 19(th) centuries, first half of the 20(th) century, second half of the 20(th) century and the late 20(th) and 21(th) century) according to the types of studies performed in each of them. Moreover, we also briefly review the history of echinostome infections in humans.
Subject(s)
Parasitology/history , Trematoda/genetics , Trematoda/physiology , Trematode Infections/parasitology , Animals , History, 18th Century , History, 19th Century , History, 20th Century , History, 21st Century , Humans , Research/history , Species SpecificityABSTRACT
OUR STUDIES REVEAL PREVIOUSLY UNIDENTIFIED ELECTRICAL PROPERTIES OF CHROMOSOMES: (1) chromosomes are amazingly similar in construction and function to electrical transformers; (2) chromosomes possess in their construction and function, components similar to those of electric generators, conductors, condensers, switches, and other components of electrical circuits; (3) chromosomes demonstrate in nano-scale level electromagnetic interactions, resonance, fusion and other phenomena similar to those described by equations in classical physics. These electrical properties and phenomena provide a possible explanation for unclear and poorly understood mechanisms in clinical genetics including: (a) electrically based mechanisms responsible for breaks, translocations, fusions, and other chromosomal abnormalities associated with cancer, intellectual disability, infertility, pregnancy loss, Down syndrome, and other genetic disorders; (b) electrically based mechanisms involved in crossing over, non-disjunction and other events during meiosis and mitosis; (c) mechanisms demonstrating heterochromatin to be electrically active and genetically important.
ABSTRACT
This review is mainly concerned with the methods used to study collar spines in echinostomatid trematodes. The salient studies concerned with light microscopy on live and fixed larval and adult echinostomes are reviewed. Similar information is also provided for echinostomatid collar spines examined by scanning electron microscopy and transmission electron miscroscopy. The limited information on specific histochemical studies on these spines is also reviewed. Lastly, an examination of the few papers that have considered structure and function of collar spines is given.
Subject(s)
Echinostoma/anatomy & histology , Animals , Microscopy/methods , Microscopy, Electron, Scanning/methods , Microscopy, Electron, Transmission/methodsABSTRACT
This paper discusses collar spine arrangements in the genus Echinostoma. All arrangements are of uneven numbers of collar spines on the oral collar. The total number of collar spines in these arrangements ranges from a low 31 to a high 51. There are 11 models of collar spine arrangements in the Echinostoma consisting of spine numbers 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, and 51. Representative species with these collar spine arrangements are given in the article. The number of collar spines in a species is identical in both the larval and adult forms. Reports of even numbered spine counts in the genus Echinostoma are erroneous and probably reflect counts on worms with lost, retracted, or supernumerary spines.
Subject(s)
Animal Structures/anatomy & histology , Echinostomatidae/anatomy & histology , Animals , Larva/anatomy & histologyABSTRACT
This study was done to help us answer numerous requests that we get about the identity of 45-collar-spined echinostomes in the genus Echinoparyphium. We examined 45-collar-spined cercariae from physid snails collected in Europe and the USA. Morphological observations of these cercariae showed considerable similarities in most of the characteristics we examined in these cercariae. Similar findings were made of adults obtained from natural and experimentally infected avian hosts in Europe and the USA. We suggest that these echinostomes be considered as species in the Echinoparyphium recurvatum complex, until further morphological and molecular studies be done on this group.
