The ecsoma in Hemiuridae (Digenea: Hemiuroidea): tegumental structure and function in the mesocercaria and the metacercaria of Lecithochirium furcolabiatum (Jones, 1933) Dawes, 1947

1988 ◽  
Vol 62 (4) ◽  
pp. 317-330 ◽  
Author(s):  
B. F. Matthews ◽  
R. A. Matthews
Keyword(s):  
Harpacticoid Copepod ◽  
Structure And Function ◽  
The Body ◽  
Excretory Vesicle ◽  
Intermediate Hosts ◽  
Distal Half ◽  
Body Regions ◽  
And Function ◽  
Two Stages ◽  
Advanced Development

AbstractUltrastructural, histochemical and autoradiographical techniques have been used to investigate the development and function of the tegument of both somal and ecsomal body regions in the hemiurid Lecithochirum furcolabiatum. The terms mesocercaria and metacercaria are here adopted for those stages in the copepod second and fish third intermediate hosts respectively on the basis of morphology and on analogy with the Strigeidae. Mesocercariae were obtained by experimental infection of the harpacticoid copepod Tigriopus brevicornis with the cystophorous cercariae (syn. Cercaria vaullegeardi), whilst metacercariae were removed from the body cavities of naturally-infected rockpool teleosts including Gobius paganellus and Blennius pholis. Observations on the mesocercaria show the origin of the ecsoma from the distal half of the excretory vesicle, which at 21 days post-infection is capable of eversion through the terminal pore. The nucleated microrugous surface layer of the ecsoma at this stage is modified or replaced in the metacercaria by anucleate syncytial tegument similar to that of the adult organ. The metacercarial stage is also associated with the more advanced development of the somal tegument. The two stages differ in metabolic activity, the somal tegument of only the metacercaria resembling that of the adult in acid phosphatase distribution. In the mesocercaria the ecsomal tegument showed the strongest uptake of 3H-tyrosine; absorption of the latter was not detected in the metacercaria. 3H-glucose uptake was restricted to the intestinal caeca of both stages.

scholarly journals Evidence of Regeneration of Testicular and Epididymal Tissue Structure and Function Following Withdrawal from Sub-chronic Khat Exposure: Studies in the Rabbit Animal Model

2020 ◽  
pp. 10-23
Author(s):  
Albert W. Nyongesaa ◽  
Esther M. Malukib ◽  
Jemimah A. Simbaunib
Keyword(s):  
Body Weight ◽  
Chronic Exposure ◽  
Structure And Function ◽  
The Body ◽  
Endocrine Function ◽  
Eastern Africa ◽  
Blood Samples ◽  
Middle East Countries ◽  
Group I ◽  
And Function

Khat, Catha edulis, use is rampant in Eastern Africa and Middle East countries with associated reports of reproductive function impairment in the body of the user. Reports on recovery post long-term khat exposure are obscure. The present study investigated evidence of restoration of testicular and epididymal structure and function during withdrawal from cytotoxic damage caused by sub-chronic exposure of khat extract. Twenty-eight male rabbits were divided into 7 groups of 4 rabbits each. Group I (control) was administered normal saline while groups II, III and IV were administered 1.0 g/kg, 10 g/kg and 20 g/kg body weight of khat extract, respectively, via oral gavage on alternate days of the week for 12 weeks. Blood samples from animals were collected for hormonal assays followed by euthanasia using 26.4 mg/kg body weight of Sagatal sodium intramuscularly for testicular and epididymal histology. Group V, VI and VII were administered 1.0 g/kg, 10 g/kg and 20 g/kg body weight of khat extract, respectively, orally on alternate days of the week for 12 weeks followed by 1-month withdrawal period, blood samples collected for hormone assays and animals sacrificed for testicular and epididymal histology. High khat dose, 20 g/kg body weight, at sub-chronic exposure caused degeneration in spermatogenic cells with accompanying decrease in plasma FSH and testosterone. Histological output of Sertoli cells, Leydig cells and epididymal epithelium appeared unaffected in treatment groups. Post withdrawal data showed apparent regeneration of seminiferous epithelium and restoration of plasma FSH and testosterone comparable to control. It appears khat extract preferentially affected germ cell spermatogonia and subsequent daughter cells while stem cell spermatogonia were unaffected and contributed to regeneration of germinal epithelium and endocrine function.

Cellular structure and function

2021 ◽  
pp. 1-104
Keyword(s):  
Plasma Membrane ◽  
Nucleic Acids ◽  
Cellular Structure ◽  
Structure And Function ◽  
The Body ◽  
Signalling Pathways ◽  
Cellular Functions ◽  
Pharmacological Agents ◽  
Intracellular Organelles ◽  
And Function

‘Cellular structure and function’ covers the roles, structures, and functions of the main four types of macromolecules of the human body, namely proteins, lipids, carbohydrates, and nucleic acids. For these macromolecules, the roles and types of each class are discussed (for proteins this includes their roles as structural proteins and enzymes and their kinetics; for lipids, the roles and types of lipid found in the body are considered; for carbohydrates, their roles including structural and metabolic are discussed; and the structure of nucleic acids is described). Then follows a description of the organization of the cell, including the plasma membrane and its components, and the intracellular organelles. Cell growth, division, and apoptosis are covered, as are the formation of gametes, and finally the principles of how cellular functions can be modulated by pharmacological agents through receptors and signalling pathways are discussed.

scholarly journals Structure and Function of the Body

1969 ◽  
Vol 69 (5) ◽  
pp. 1075
Author(s):  
Faustena Blaisdell ◽  
Catherine Parker Anthony
Keyword(s):  
Structure And Function ◽  
The Body ◽  
And Function

scholarly journals Structural Characterization of Carbonic Anhydrase VIII and Effects of Missense Single Nucleotide Variations to Protein Structure and Function

2020 ◽  
Vol 21 (8) ◽  
pp. 2764
Author(s):  
Taremekedzwa Allan Sanyanga ◽  
Özlem Tastan Bishop
Keyword(s):  
Carbonic Anhydrase ◽  
Binding Site ◽  
Cross Correlation ◽  
Structure And Function ◽  
The Body ◽  
Conformational Sampling ◽  
Nucleotide Polymorphisms ◽  
Ip3 Receptor ◽  
Single Nucleotide ◽  
And Function

Human carbonic anhydrase 8 (CA-VIII) is an acatalytic isoform of the α -CA family. Though the protein cannot hydrate CO2, CA-VIII is essential for calcium (Ca2+) homeostasis within the body, and achieves this by allosterically inhibiting the binding of inositol 1,4,5-triphosphate (IP3) to the IP3 receptor type 1 (ITPR1) protein. However, the mechanism of interaction of CA-VIII to ITPR1 is not well understood. In addition, functional defects to CA-VIII due to non-synonymous single nucleotide polymorphisms (nsSNVs) result in Ca2+ dysregulation and the development of the phenotypes such as cerebellar ataxia, mental retardation and disequilibrium syndrome 3 (CAMRQ3). The pathogenesis of CAMRQ3 is also not well understood. The structure and function of CA-VIII was characterised, and pathogenesis of CAMRQ3 investigated. Structural and functional characterisation of CA-VIII was conducted through SiteMap and CPORT to identify potential binding site residues. The effects of four pathogenic nsSNVs, S100A, S100P, G162R and R237Q, and two benign S100L and E109D variants on CA-VIII structure and function was then investigated using molecular dynamics (MD) simulations, dynamic cross correlation (DCC) and dynamic residue network (DRN) analysis. SiteMap and CPORT analyses identified 38 unique CA-VIII residues that could potentially bind to ITPR1. MD analysis revealed less conformational sampling within the variant proteins and highlighted potential increases to variant protein rigidity. Dynamic cross correlation (DCC) showed that wild-type (WT) protein residue motion is predominately anti-correlated, with variant proteins showing no correlation to greater residue correlation. DRN revealed variant-associated increases to the accessibility of the N-terminal binding site residues, which could have implications for associations with ITPR1, and further highlighted differences to the mechanism of benign and pathogenic variants. SNV presence is associated with a reduction to the usage of Trp37 in all variants, which has implications for CA-VIII stability. The differences to variant mechanisms can be further investigated to understand pathogenesis of CAMRQ3, enhancing precision medicine-related studies into CA-VIII.

Agent-Based Modeling of Gates Assignment System

2012 ◽  
Vol 235 ◽  
pp. 368-372
Author(s):  
Wei Gao ◽  
Hui Min Huang
Keyword(s):  
Structure And Function ◽  
Agent Based Modeling ◽  
Agent Technology ◽  
Working Process ◽  
Flight Delays ◽  
Agent Based ◽  
Gate Assignment ◽  
Plan Making ◽  
And Function ◽  
Two Stages

The optimization of Gate Assignment System is to reduce flight delays and improve the operation efficiency of airports, due to many complex factors and vulnerably sudden situation. Through analyzing the working process of gates assignment system and the rules of Agent technology, Agent concept is introduced into Gate Assignment System and a modeling architecture of Agent-based system is put forward, as well as the structure and function of each Agent is declared and the communication and collaboration mechanism among Agents is recommended. Additionally, in the framework construction, the Agents interaction is divided into two stages, or plan making and plan implementing, in order to realize the real-time adjustment of the whole assignment system. The results could be references for other related studies.

The Alimentary Canal of Calliphora erythrocephala L., with Special Reference to its Musculature and to the Proventriculus, Rectal Valve and Rectal Papillae

Parasitology ◽  
1934 ◽  
Vol 26 (2) ◽  
pp. 176-248 ◽  
Author(s):  
G. S. Graham-Smith
Keyword(s):  
Special Reference ◽  
Body Fluid ◽  
Alimentary Canal ◽  
Liver Cells ◽  
Structure And Function ◽  
The Body ◽  
Calliphora Erythrocephala ◽  
And Function

A detailed description of the musculature in the different regions of the alimentary canal of Calliphora erythrocephala is given, and an account of the structure and function of the crop, proventriculus, ducts of the Malpighian tubes, rectal valve and rectal papillae. It has been shown by dissections and experiments that a system of channels exists in the rectal papillae through which the body fluid probably circulates, and it is suggested that the very large cells may have functions resembling those of liver cells.

The history of the capillary wall: doctors, discoveries, and debates

2007 ◽  
Vol 293 (5) ◽  
pp. H2667-H2679 ◽  
Author(s):  
Charlotte Hwa ◽  
William C. Aird
Keyword(s):  
Basic Structure ◽  
Structure And Function ◽  
The Body ◽  
Capillary Wall ◽  
Central Importance ◽  
Definitive Evidence ◽  
Arterial Blood ◽  
History Of ◽  
And Function

In 1628, William Harvey provided definitive evidence that blood circulates. The notion that blood travels around the body in a circle raised the important question of how nutrients pass between blood and underlying tissue. Perhaps, Harvey posited, arterial blood pours into the flesh as into a sponge, only then to find its way into the veins. Far from solving this problem, Marcello Malpighi's discovery of the capillaries in 1661 only added to the dilemma: surely, some argued, these entities are little more than channels drilled into tissues around them. As we discuss in this review, it would take over 200 years to arrive at a consensus on the basic structure and function of the capillary wall. A consideration of the history of this period provides interesting insights into not only the central importance of the capillary as a focus of investigation, but also the enormous challenges associated with studying these elusive structures.

scholarly journals Inclusive Design: Systems Interaction Society - Textile Means of Rehabilitation - Child

2020 ◽  
Vol 6 (1) ◽  
pp. 198-206
Author(s):  
A. Golubchikova ◽  
N. Korobtseva
Keyword(s):  
Quality Of Life ◽  
Children With Disabilities ◽  
Emotional State ◽  
Structure And Function ◽  
The Body ◽  
Basic Principles ◽  
External Appearance ◽  
Design Systems ◽  
And Function

One of the goals of rehabilitation of children with disabilities (HHS) is to improve their quality of life. For this purpose, various technical means, devices and adaptations which solve a number of problems in life of the child are developed. But there is another aspect that affects the quality of life of such children — is the attitude of people around them. The child is emotionally unstable individual, his psyche is very vulnerable to react to negative emotions. In this case the saying that ‘meet on clothes’ is very applicable. And if the child looks aesthetically pleasing, then others perceive him positively. But in some diseases (physical deviations from the norm) there is no ergonomic and aesthetic clothing. The paper considers the interaction of the systems Society — Textile means of rehabilitation — Child. It is revealed that textile means of rehabilitation, including inclusive clothing have an impact not only on the child’s condition, but also on the emotional state of the society in contact with him, especially his parents. Research on the systematization of information about violations of the structure and function of the body allowed to identify and group the possible causes of violations of the proportions of the child’s body. Some can be compensated by the use of fixing products, others through the use of illusions that contribute to the visual alignment of the proportions of the child. The article formulates the basic principles of designing textile means of rehabilitation and inclusive clothing for children with disabilities, aimed at harmonizing the perception of the external appearance of the child.

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