Structure Of Body Wall Research Articles

Studies on the mechanism of the contact toxicity of carvone against Tribolium castaneum

Carvone exhibits significant insecticidal activity against Tribolium castaneum. Whereas, the precise underlying mechanism of carvone's toxicity remains elusive. In this study, we aimed to investigate the contact toxicity mechanism of carvone on T. castaneum through a comprehensive set of experiments. These experiments included observation of poisoning symptoms in T. castaneum, a time-mortality test, analysis of weight measurement and respiration activities, histological assessment, enzymatic assays, and molecular simulation studies. Physiological analyses show that carvone induces excitement, spasms, and a comatose state in T. castaneum, accompanied by darkening of the body surface. Survival rates significantly dropped by 44% after 8–12 h of carvone treatment. Carvone also affects metabolism, increasing CO2 release and body weight loss. Histopathological examination reveals changes in the body wall structure, including wax particle shape alterations, increased gaps, and damaged hair bases. Abdominal tissue examination shows impacts on muscle and fat tissues, leading to dehydration and impaired physiological functions. Key enzymatic assays demonstrate sustained inhibition of acetylcholinesterase and succinate dehydrogenase activity by carvone, with peak inhibition rates reaching 65.15% and 39.90%, respectively. Carvone exhibits a biphasic effect on ATPases and activates glutathione S-transferase while inhibiting carboxylesterase activity. Molecular docking analysis reveals direct interactions between carvone and acetylcholinesterase in T. castaneum, suggesting its inhibition mechanism. This study provides insights into the insecticidal mechanism of carvone on T. castaneum and contributes to the development of plant-based insecticides.

The combined effects of polystyrene nanoplastics with nickel on oxidative stress and related toxic effects to earthworms from individual and cellular perspectives

Nanoplastics may adsorb other pollutants in the environment due to their high specific surface area and small size. We used earthworms as experimental organisms to evaluate the ecotoxicity of NPs and Ni combined pollution at the individual and cellular levels. The results showed that when only 20 mg/L Ni2+ was added to the combined pollution system, the antioxidant system of earthworm coelomocytes was destroyed to a certain extent, the ROS level increased, the cell viability decreased significantly, and the redox balance was destroyed. With the introduction of PS-NPs and the increase of concentration, the oxidative damage in the coelomocytes of earthworms gradually increased, and finally tended to be stable when the maximum concentration of 50 mg/L PS-NPs and Ni were exposed together. At the animal level, the activities of CAT and SOD decreased within 28 days of exposure, and the combined pollution showed a synergistic effect. At the same time, it promoted the synthesis of GST in earthworms, improved their detoxification ability and reduced oxidative damage. The changes of T-AOC and MDA showed that the combined pollution caused the accumulation of ROS and caused more serious toxicological effects. With the increase of exposure time, the antioxidant system of earthworms was continuously destroyed, and the oxidative damage was serious, which induced more serious lipid peroxidation and caused the damage of earthworm body wall structure.

Implications of comparative ventral body wall histology on selection of abdominal surgical approach and closure in 12 species of fish.

A ventral midline surgical approach for fish celiotomy is commonly performed in veterinary clinical medicine and research, although the relevant ventral body wall anatomy of many fish species is not well documented. Histological evaluation of tissue samples from the ventral body wall of 12 fish species was performed to provide a reference for surgical approach and closure decisions. The width between muscle bundles running parallel to the long axis and total thickness of tissue layers varied among species. An appreciable space between longitudinal muscles of the ventral body wall and a lack of muscle, vessels and nerves on midline in all species examined supports recommendations of ventral midline incisions to spare important structures. Dense connective tissue consistent with an aponeurosis between musculature along the ventral body wall was not observed in any species evaluated. Connective tissue was concentrated within the dermis of all species evaluated, with an additional layer of collagen along the coelomic membrane in Russian sturgeon Acipenser gueldenstaedtii, koi Cyprinus carpio, goldfish Carassius auratus, black drum Pogonias cromis, black seabass Centropristis striata, tomtate Haemulon aurolineatum and scup Stenotomus caprinus. A sufficiently wide space on ventral midline for practical targeting during the surgical approach is present in A. gueldenstaedtii, C. carpio, striped bass Morone saxatilis, H. aurolineatum, P. cromis, rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta. Sand perch Diplectrum formosum, C. auratus, S. caprinus, grey triggerfish Balistes capriscus and black sea bass Centropristis striata have a negligible space between longitudinal muscles on midline. The variation in ventral body wall structure observed in this study helps inform surgical decision making for celiotomy incision and closure in these species.

<p align="left"><strong>Differing infection of<em> Isaria fumosorosea </em>(Wize) Brown & Smith in an aphid (<em>Myzus persicae</em> [Sulzer]) and predatory mite (<em>Neoseiulus cucumeris </em>[Oudemans]) under a scanning electron microscope</strong></p>

Implementing a predator-mediated pathogen dissemination system can meet the goal of simultaneous biocontrol of harmful mites and other pests. But for the system to be effective, it must satisfy the requirement of high lethality of the pathogen to the target pest(s) with low lethality to predatory mites in a suitable environment. Prior testing showed that the fungal entomopathogen Isaria fumosorosea (Wize) Brown & Smith exhibited high toxicity to aphids yet low toxicity to the predatory mite Neoseiulus cucumeris (Oudemans). In practical application, the humidity conditions of conidia carried by predatory mites to plants are not necessarily constant. Therefore, we set two different humidity conditions to observe the changes of spore attachment quantity and the differences of germination and infection between predatory mites and aphids after their bodies were stained with spores. Under 50±1% relative humidity (RH), predatory mites cleaned most spores in a short time; 24 hours after dusting, the number of spores (mean ± SD) on body was (0.64±0.10)×103, just (4.43±0.35)% of that at 0h, but spores on aphids were kept (16.58±1.48)% ((6.46±0.91)×103 spores) of that at beginning. There was a significant difference in the percentage of spores retained on aphids and predatory mites (p=0.000<0.01). Humidity could affect the cleaning behavior; under 95± 1% RH (the suitable humidity for conidia germination), more spores persisted than that under the 50 ± 1% RH condition; at 24h, the numbers of spores on each predatory mite and aphid were (1.00±0.10)×103 and (10.02±2.87)×103. Here, under a scanning electron microscope, we found that spores on the aphid’s body germinated 36 hours after dusting under 95± 1% RH, and the I. fumosorosea mycelium had spread after 48 hours; many new mycelium and spores were produced after 72 hours. In stark contrast, few spores germinated on the mite’s body, thus leading to very little damage to its surface. Different cleaning behavior and different morphological structure of body wall can both affect the attachment and infection of I. fumosorosea to aphids and predatory mites. In the future, chemical substance, enzyme and other factors should also be researched to explain the difference of infection of entomopathogenic fungi to different species.

STABILITY PERFORMANCE OF INFLATABLE TUBE IMITATING CLANIS BILINEATA LARVA UNDER AXIAL PRESSURE

The body wall structure of Clanis bilineata larva exhibits strong stability. This characteristic prompted the development of a new inflatable tube to improve the stability under axial pressure. The C. bilineata larva was chosen to observe the connection between its body wall and nearby muscle tissues, as well as the distribution of these tissues, by using the tissue section technique. Using this method, an inflatable tube with reinforcing ribs was designed. Simulation using the finite element method and experimentation were employed to compare and analyze the stability of the inflatable tube with and without reinforcing ribs under different axial pressure levels. Results indicate that the ultimate load of both inflatable tubes increases linearly with increasing pressure. The difference between the slopes of the two lines is small. Under different axial pressure levels, the ultimate load of the inflatable tube with reinforcing ribs is about 1.34[Formula: see text]N higher than that without reinforcing ribs; the ultimate compression power increased by 31% to 68% compared with that without ribs. The simulation results are slightly larger than the experimental results, but the ultimate load value in the simulation exhibits the same trend as that in the experiment. Finally, the limit load and ultimate compression power are used as evaluation criteria to quantitatively analyze the stability performance of an inflatable tube with reinforcing ribs under axial pressure.

Comparative morphology of the body wall in flatworms (Platyhelminthes)

The soft-bodied nature of the platyhelminths is due largely to the structure of the body wall and its lack of sclerotic elements such as cuticle. Free-living members, i.e., most turbellarians, show considerable variety, but the basic form of the body wall comprises a simple ciliated epithelium overlying a network of muscles. We illustrate this body wall structure in a representative typhloplanoid rhabditophoran and discuss variations in representatives of the Acoela, Catenulida, and other free-living rhabditophorans. The major parasitic groups of platyhelminths, the rhabditophoran Neodermata, follow a developmental pattern that replaces a similar ciliated epidermis in a larval stage with a specialized epidermis called a neodermis, which is assumed to be key to their success as parasites. This neodermis consists of a syncytium that covers the body in a continuous sheet connected to perikarya that lie below the body wall musculature. The neodermis can be seen as a special adaptation of a developmental mechanism common to all platyhelminths, in which epidermal growth and renewal are accomplished by replacement cells originating beneath the body wall. The cell type responsible for all cell renewal, including body wall renewal, in platyhelminths is the neoblast, and its presence may be the one autapomorphic character that unites all taxonomic groups of platyhelminths.

A comparative study on the fusogenic nature of echinoderm and nonechinoderm phagocytes in vitro

AbstractPhagocytes obtained from six echinoderm and four nonechinoderm species are compared in culture with respect to their ability to form syncytium. It is shown that phagocytes of all echinoderm species examined form an extensive syncytium while those of three nonechinoderm species shoe no such activity. Phagocytes of an ascidia, on the other hand, formed a less extensive type of syncytium known as a multinucleate giant cell. Kinetic analyses of the process of fusion were performed. Phagocytes of the asteroid, Asterina pectinifera, fuse more readily when transferred to culture condition in an aggregated state than as single cells. The extraordinarily fusogenic nature of echinoderm phagocyte is discussed in relation to the calcareous body wall structure of the echinoderms. © 1993 Wiley‐Liss, Inc.

Fetal movements; factors affecting their perception

We prospectively recorded placental site, maternal weight and parity in 182 patients reporting decreased fetal movements and compared these with controls. Reports of decreased fetal movements were 2.10 times (95% CI 1.51–2.92) as likely in association with an anterior placenta and 1.81 times (95% CI 1.20–2.93) and 2.61 times (95% CI 1.26–5.40) as likely in mothers weighing over 80 and 90 kg, respectively, but there was no association with parity. Decreased perception of fetal movements is more likely to have serious implications in thin women with a posterior placenta. Our findings also suggest that the sensation of fetal movements arises from pressure against body wall structures rather than the uterus or peritoneum.

Glycosaminoglycan Involved in the Cation-Induced Change of Body Wall Structure of Sea CucumberStichopus Japonicus

The body wall of sea cucumber Stichopus japonicus was treated with various concentrations of several cations, and examined for changes in toughness, taking punch force as parameter. Toughness of the body wall tended to decrease with increasing concentration of each cation, but in different modes depending mainly upon the valency of cation: e.g., the body wall completely lost toughness in 0.3 M Na+ or 0.4 M K+, whereas it retained more than half the initial toughness even in 0.4 M Ca2+ or Mg2+. Glycosaminoglycan (GAG) from the body wall was dissolved in water, and examined for viscosity changes as caused by those cations. Specific viscosity (eta sp) decreased from 0.71 (without cation) to 0.47-0.57 in the presence of 0.1 M monovalent and divalent cations. At 0.4 M, monovalent cations reduced eta sp to 0.38-0.46, but divalent cations increased eta sp to 0.56-0.63. Electron microscopy demonstrated that GAG matrix was clearly observed in the absence of cation, but disappeared in 0.4 M NaCl, forming wide free spaces in the body wall. These results all suggested that GAG is closely involved in the change of toughness of sea cucumber body wall.

Mechanical responses of the body wall strips of an echiuroid worm, Urechis unicinctus, to electrical stimulation, cholinergic agents and amino acids

1. 1. Several amino acids and cholinergic agents could elicit contraction in the body wall strips of U. unicinctus; L-proline was the most effective. 2. 2. Pharmacological studies on the contradictions of the strips and light microscopic observations of the body wall structures suggested that contradiction in response to cholinergic agents was brought about by their direct action on the body wall muscle fibres while the contraction in response to amino acids was induced by their action on the epidermal chemoreceptor organs. 3. 3. ACh may be an excitatory transmitter at the neuromuscular junctions in the body wall.

Identification of genetic elements associated with muscle structure in the nematode Caenorhabditis elegans.

A search for new mutants with altered body-wall muscle cell structure has been undertaken in the nematode C elegans. One-hundred seventeen mutants were isolated after mutagenesis with ethyl methanesulfonate or ultraviolet light, enrichment by a motility-requiring test, and screening by polarized light microscopy; 102 of these mutants were in ten previously established genes, whereas 15 mutants permitted the identification of seven new complementation groups in C elegans. Two of the new genes map on linkage group I (unc-94 and unc-95) and four genes are sex linked (unc-96, unc-97, unc-98, and unc-99). One complementation group (unc-100) could not be mapped because of the special characteristics of its cohort mutants. Representative mutants of the mapped genes were examined by polarized light and electron microscopy. All of the mutants exhibit disruptions of the normal A and I band organization of thick and thin filaments. Several of the mutants produce collections of thin filament-like structures. In one of these cases, HE177 demonstrated collections of somewhat wider, intermediate-sized filaments as well, and the HE195 mutant produces paracrystalline aggregates of thin filaments amidst looser arrangements of similar structures. The mutants in newly identified genes, as well as the new mutants in previously established genetic loci, have promise as tools in the study of myofibrillar assembly and function. Among the 22 complementation groups associated with body-wall structure in C elegans, it is likely that some genes code for regulatory and morphogenetic functions in addition to the well-studied structural, contractile, and calcium-associated proteins in muscle.

A new specialization of the granular endoplasmic reticulum in the uterine glands of the pig in the later stages of pregnancy.

ABSTRACT A new specialization of the granular endoplasmic reticulum (GER) which develops within the uterine gland cells of the pig during the final third of pregnancy is described. The ‘tubular bodies ‘are interpreted as sheets of GER rolled up to form open-ended cylinders enclosing cytoplasm which is distinctly less electron-dense than the surrounding external cytoplasm, and in which large clear vesicles and free ribosomes are frequently found. The tubular bodies are not present during the first two thirds of pregnancy, but by day 100 of gestation they are readily discerned. They increase in number within the last week of pregnancy and are still found in glands from the day 1 post-partum uterus. They are distributed, either singly or in groups of up to 30 or more units, throughout the cells. The cisternal space which surrounds them is continuous with that of the granular endoplasmic reticulum. A tentative developmental sequence is suggested, based on morphological similarities between the wall structure of the early tubular body and the paired cistemae, which are seen scattered as single, short strands within the gland cells. The final form is achieved by modification of the inner apposed, ribosome-free cisternal membranes into the straightened-out, thickened membranes characteristic of the tubular body wall, together with a rolling-up of the ‘sheet’ of paired GER cistemae. Subsequent loss of the innermost unmodified cisternal membrane which is now in contact with the centrally enclosed cytoplasm results in the characteristic tubular body wall structure. The characteristic appearance of the central cytoplasm and the presence of modified surrounding membranes suggests the possibility of a localized, modified internal environment required for some unspecified functional activity; possibly a synthetic process or some type of ionic regulation.

Trichinella spiralis: Fine structure of body wall with special reference to formation and moulting of cuticle

The body wall of the immediate postembryonic juvenile, the preinfective juvenile, the infective juvenile, the moulting juvenile in the host's intestine and the adult of Trichinella spiralis was examined with the electron microscope. The structure and probable mode of development (secretion from the hypodermis) are described. The basic structure of the “mature” cuticle is an outer three-layered membrane, two cortex layers, a medial layer which in the adult is striated, and two fibril layers. The cuticle is attached to an outer corrugated hypodermal membrane by means of desmosomes on the crests of the corrugations. It is thought that the secretion of the cuticle occurs in the trough regions. The hypodermis has the appearance of a highly active layer with an abundance of ribosomes and mitochondria. The hypodermis is cellular and is not a syncytium. Bacillary cells have been demonstrated for the first time in the lateral hypodermal cords of adult T. spiralis. The body wall muscle is similar in structure to that of other nematodes but an increase in the number of muscle cells per intercordal sector from the first-stage juvenile to the adult is recorded and some doubt is therefore cast on the concept of cell constancy in nematodes.

Fine Structure of the Tegument of the Miracidium of Fasciola hepatica L.

The fine structure of the tegument of the miracidium of Fasciola hepatica is described. Ciliated epithelial cells overlie a thin discontinuous layer of cytoplasm. This is thickened between adjacent epithelial cells to form prominent intercellular ridges. The thin layer of cytoplasm is associated with diffuse extracellular fibrous material. Beneath the thin layer are circular and longitudinal muscle fibers and beneath these again are large (ca. 10, in diameter) vesiculated cells. The vesiculated cells communicate with the thin cytoplasmic layer by means of narrow cytoplasmic connections running between adjacent muscle fibers. Small electron-opaque vesicles are found in the vesiculated cells, thin cytoplasmic layer, and intercellular ridges. Flattened membranous bodies are also present in the intercellular ridges. The surface of the miracidium is covered with a layer of alcian blue-positive material which appears to be continuously secreted and is presumed to be acid mucopolysaccharide. The apical papilla has an array of circular and longitudinal muscle fibers attached to each other by numerous small desmosomes. The surface of the papilla lacks ciliated epithelial cells and is covered instead by a layer of corrugated cytoplasm. The structure of the miracidium of Fasciola hepatica has been described in detail at the light microscope level by Mattes (1949) and Dawes (1960), and there have been many studies on other miracidia (e.g. Price, 1931; Lynch, 1933; D6nges, 1964). The ultrastructure of the flame cells of the miracidium of Fasciola was described by Kiimmel (1958, 1959), and that of the miracidial eyespots by Kiimmel (1960), Isseroff (1964), and Isseroff and Cable (1968), but other aspects of fine structure do not appear to have been investigated. The above accounts give some indication of variations in structure, at least between miracidia from different families. Lee (1966) reviewed the structure and composition of the helminth body wall and pointed out that little work has been done on the fine structure of the body wall of larval trematodes. Descriptions of rediae have been given by Rees (1966), and Krupa et al. (1967); of a cercaria by Belton and Harris (1967); and of a daughter sporocyst by James et al. (1966). With the exception of the daughter sporocyst, the body surface was an anucleate cytoplasmic syncytium separated from the body wall musculature by an acellular basement membrane. In the case of the daughter sporocyst, the outer layer was nucleated. The miracidium stage in the digene life cycle has a body surface covered with discrete epithelial cells and Dawes (1960) has shown that, in Fasciola at Received for publication 17 June 1968. least, these cells are shed prior to penetration of the miracidium into the snail. This paper presents the results of an investigation into the fine structure of the tegument of the miracidium of Fasciola hepatica. MATERIALS AND METHODS Infected sheep livers were obtained from the local slaughterhouse and mature flukes dissected out. Undeveloped eggs were teased from flukes into distilled water and incubated for 12 days at 25 C in the dark. Mass hatching of miracidia into a minimal volume of water was brought about by exposure to light. Miracidia were fixed at 4 C, 20 min after exposure of eggs to light, in either Zetterquist's buffered osmium tetroxide for 1 to 4 hr (after Kay, 1965), or 3% glutaraldehyde in cacodylate buffer pH 7.2 for 30 min followed by postfixation in osmium for 4 hr. Miracidia were dehydrated in alcohol and embedded in an araldite-epon mixture. Prior to sectioning, individual miracidia were isolated in small pieces of cured resin and oriented transversely or longitudinally on top of a perspex rod, being fixed in position with araldite adhesive. Sections were cut on a Huxley ultramicrotome and collected on grids coated with formvar and carbon. Specimens were stained either with uranyl acetate during dehydration followed by lead citrate on the grid, or by both uranyl acetate and lead citrate on the grid. Sections were viewed in an AEI EMB6 electron microscope operating at 60 KV.