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1.
Histological study of the nasal cavities and upper maxillae of Arvicanthis niloticus naturally infected with Trichosomoides nasalis shows that the female worms reside in the epithelial monolayer of the nasal mucosa of the posterior and median cavities. Eggs laid by T. nasalis were infiltrated between the female body wall and the epithelial lining. Small groups of eggs, mixed with mucus and polymorphonuclear cells, were found in the nasal lumen, freed by rupture of the stretched epithelium. Two females and a few eggs were also found in the connective tissues. One male was found in a female uterus and two were apparently in the lumen of the nasal cavity but the surrounding tissues were disrupted. No male was identified in the lamina propria of the mucosa. However, significant inflammatory lesions occurred in the lamina propria, similar to those induced by the males of Anatrichosoma spp. which live in this part of the mucosa. In rodents, the lesions resulted in rhinosinusitis characterised by a lymphocytic infiltration leading to nasal obstruction.  相似文献   

2.
A new cephalobaenid pentastome, Rileyella petauri gen: nov., sp. nov. from the lungs and nasal sinus of the petaurid marsupial, Petaurus breviceps, is described. It is the smallest adult pentastome known to date, represents the first record of a mammal as the definitive host of a cephalobaenid and may represent the only pentastome known to inhabit the lungs of a mammal through all its instars, with the exception of patent females. Adult males, non-gravid females and nymphs moulting to adults occur in the lungs; gravid females occur in the nasal sinus. R. petauri is minute and possesses morphological features primarily of the Cephalobaenida but the glands in the cephalothorax and the morphology of the copulatory spicules are similar to some members of the remaining pentastomid order, the Porocephalida. This unusual combination of features distinguish the new genus from other genera in the Cephalobaenida. The occurrence of only seven fully-formed larvae in eggs in the uterus, each representing about 10% of the length of the patent female, and her presence in the nasal sinus of a dependent juvenile P. breviceps (36 gm) implies a direct life cycle.  相似文献   

3.
Summary The morphology and life-cycle of Trichobilharzia arcuata n. sp. from the nasal blood vessels of Dendrocygna arcuata from northern Australia are described. T. arcuata is distinguished from all species of Trichobilharzia except T. australis and African nasal schistosomes by its location in the nasal blood vessels and by the cercariae having 16 flame cells with a formula 2[(3)+(4+1)] against 14 with a formula 2[(3)+(3+1)], or 12 with a formula 2[(3)+(2+1)] in the case of T. corvi. T. arcuata differs from the five African nasal schistosomes in the nature of the tegument, the position of the male genital papilla and the shape of the eggs and from T. australis in the position of the caecal reunion, the number of testes, the absence of spines on the ventral tegument between the ovary and the seminal receptacle, the shape of the eggs and the presence of two germinal masses in the miracidium. Lymnaea lessoni exposed to miracidia of T. arcuata developed patent infection in 22 to 41 days. Intramolluscan development of T. arcuata is similar to T. stagnicolae and T. physellae. Domestic Muscovy ducks and pigeons developed patent infections in 22 and 12 days respectively. Chickens, a black duck and a grey teal did not become infected. ac]19840616  相似文献   

4.
Nasal schistosomes are trematodes in the family Schistosomatidae, many members of which are causative agents of human cercarial dermatitis (HCD). Little is known about the species diversity and distribution of nasal dwelling schistosomes of water birds, particularly in countries outside of Europe; even less is known in countries like Iran. Nasal schistosomes are of particular interest since these species migrate via the central nervous system to the nasal cavity once they penetrate their host. Thus, there must be efforts to determine the incidence of HCD due to nasal schistosomes. HCD outbreaks are reported seasonally in Mazandaran Province, northern Iran, an area well known for rice cultivation leading to increased person contact with water and infected snails. Such places include favorable habitat for both domestic ducks year round, and wild migratory ducks in the winter through spring. Recent reports have detected the presence of both nasal and visceral schistosomes in ducks in this area but with little species characterization. In this study, we examine a diversity of aquatic birds to determine the distribution, prevalence and bird host use of nasal schistosomes. We apply for the first time a molecular identification and phylogenetic analysis of these schistosomes. From 2012 to 2014, the nasal cavity of 508 aquatic birds from Mazandaran Province were examined that included species in Anseriformes, Gruiformes, Charadriiformes and Phoenicopteriformes. Nasal schistosomes were found in 45 (8.9%) birds belonging to Anseriformes (Anas platyrhynchos and Anas clypeata). Phylogenetic analysis of the nuclear internal transcribed spacer 1 rDNA and the mitochondrial cytochrome oxidase1 gene of isolated eggs revealed that all samples grouped in a sister clade to the European Trichobilharzia regenti. However, Trichobilharzia from this study were more similar to a unique haplotype of Trichobilharzia, isolated from the nasals of an A. clypeata in France. The genetic and phenotypic differences between the species found herein and T. regenti from Europe, may prove with additional data to be a distinct species of Trichobilharzia.  相似文献   

5.
The avian eggshell membranes are essential elements in the fabrication of the calcified shell as a defense against bacterial penetration. Ovocalyxin-36 (OCX-36) is an abundant avian eggshell membrane protein, which shares protein sequence homology to bactericidal permeability-increasing protein (BPI), lipopolysaccharide-binding protein (LBP) and palate, lung and nasal epithelium clone (PLUNC) proteins. We have developed an efficient method to extract OCX-36 from chicken eggshell membranes for purification with cation and anion exchange chromatographies. Purified OCX-36 protein exhibited lipopolysaccharide (LPS) binding activity and bound lipopolysaccharide (LPS) from Escherichia coli O111:B4 in a dose-dependent manner. OCX-36 showed inhibitory activity against growth of Staphylococcus aureus ATCC 6538. OCX-36 single nucleotide polymorphisms (SNPs) were verified at cDNA 211 position and the corresponding proteins proline-71 (Pro-71) or serine-71 (Ser-71) were purified from eggs collected from genotyped hens. A significant difference between Pro-71 and Ser-71 OCX-36 for S. aureus lipoteichoic acid (LTA) binding activity was detected. The current study is a starting point to understand the innate immune role that OCX-36 may play in protection against bacterial invasion of both embryonated eggs (relevant to avian reproductive success) and unfertilized table eggs (relevant to food safety).  相似文献   

6.
Trichosomoides nasalis (Trichinelloidea) is a parasite of Arvicanthis niloticus (Muridae) in Senegal. Female worms that harbour dwarf males in their uteri, occur in the epithelium of the nasal mucosa. Young laboratory-bred A. niloticus were either fed females containing larvated eggs or intraperitoneally injected with motile first-stage larvae recovered from female uteri. Both resulted in successful infection. Organs examined during rodent necropsy were blood and lymphatic circulatory systems (heart, large vessels, lymphnodes), lungs, liver, kidneys, thoracic and abdominal cavities, thoracic and abdominal muscular walls, diaphragm, tongue, and nasal mucosa. Development to adult nasal stages took three weeks. Recovery of newly hatched larvae from the peritoneal fluid at four-eight hours after oral infection suggests a direct passage from the stomach or intestinal wall to the musculature. However, dissemination through the blood, as observed with Trichinella spiralis, cannot be excluded even though newly hatched larvae of T. nasalis are twice as thick (15 μm). Developing larvae were found in histological sections of the striated muscle of the abdominal and thoracic walls, and larvae in fourth moult were dissected from these sites. Adult females were found in the deep nasal mucosa where mating occurred prior to worms settling in the nasal epithelium. The present study shows a remarkable similarity between T. nasalis and Trichinella species regarding muscle tropism, but the development of T. nasalis is not arrested at the late first-larval stage and does not induce transformation of infected fibres into nurse cells. T. nasalis seems a potential model to study molecular relations between trichinelloid larvae and infected muscle fibres.  相似文献   

7.
Maternally derived hormones in cleidoic eggs have been implicated in mediating growth, behavior, and social interactions among offspring. Given these widespread and significant effects, hormonal investments have the potential to greatly influence fitness of offspring. Intraspecific variation can exist at three levels (within individual eggs, among eggs within clutches, and among eggs from different females), each of which has different implications for offspring. We characterized all three levels of variation in maternally derived androgens (testosterone and androstenedione) present in yolks of American coot eggs. We found no variation in testosterone levels within eggs which suggests that embryos are exposed to constant androgen levels during development, and that field-based yolk biopsies are an appropriate way to sample eggs for this species. Within clutches, early-laid eggs had higher androgen levels than late-laid eggs, and this pattern may exacerbate negative effects of hatching asynchrony on chicks from late-hatching eggs if androgens provide chicks with a behavioral or growth advantage over chicks from eggs with lower androgen levels. American coots lay large clutches, and unequal resource allocation among offspring may be the optimal strategy for females with access to limited resources. Most of the variation in androgen levels occurred among eggs from different females. Females nesting on ponds with two other pairs laid eggs with significantly higher androgen levels than females living on ponds with fewer pairs. This suggests that increased territory defense behaviors influence the levels of androgens allocated to eggs and may be one mechanism underlying density-dependent effects on reproduction.  相似文献   

8.
Trichobilharzia regenti is a bird nasal parasite causing human cercarial dermatitis. Schistosomula are able to migrate via the bird nervous system and then, they mature and lay eggs in the nasal cavity. To some extent they can also migrate and develop in mammals. The present study has shown the developmental differences of T. regenti in the natural (ducks) and the abnormal (mice; inbred strains BALB/c, SCID) hosts. The study describes the following parameters of developing worms: length and width of the body, length and content of the intestine, development of the reproductive organs and characterization of surface and intestinal epithelium by lectin probes. The differences in length and width of schistosomula localized in the spinal cord of various hosts cannot be simply explained and may depend on yet unknown host factors. Moreover, there must be several physiological changes during the migration through the skin, the nervous tissue and the nasal cavity, enabling uptake and digestion of different host components. For example the intestine of schistosomula was mostly filled with light-brown pigmented granules until 6 days p.i. (probably of nervous tissue origin) while the older schistosomula and adult intestine was mostly full of dark-brown pigment (probably of blood origin). Reproductive organs were observed from day 9 p.i. in worms from ducks. Whereas ConA and PSA specifically bound to the surface and intestinal epithelium of schistosomula and adults, only the labelled UEA-I lectin could be used as a surface marker of cercaria-schistosomulum transformation. The results confirmed retarded development of parasites in abnormal hosts; the factor responsible for this phenomenon should be clarified in the future.  相似文献   

9.
High levels of xenobiotic-metabolizing enzymes occur in the nasal mucosa of all species studied. In certain species, including rats and rabbits, unique enzymes are present in the nasal mucosa. The function of these enzymes is not well understood, but it is thought that they play a role in protecting the lungs from toxicity of inhalants. The observation that several nasal xenobiotic-metabolizing enzymes accept odorants as substrates may indicate that these enzymes also play a role in the olfactory process. Xenobiotic-metabolizing enzymes were found in the nasal cavity around 15 years ago. Since that time, much has been learned about the nature of the enzymes and the substrates they accept. In the present review, this information is summarized with special attention to species differences in xenobiotic-metabolizing enzymes of the nasal cavity. Such differences may be important in interpreting the results of toxicity assays in animals because rodents are apparently more susceptible to nasal toxicity after exposure to inhalants than are humans.  相似文献   

10.
Female Eider ducks, living under natural conditions, do not drink salt water during the 26 days for which they incubate their eggs. In the course of incubation the nasal salt glands decrease in size, show a marked reduction in Na+/K+-ATPase activity and in the rate at which they clear a salt load. The time course of these events is similar to that seen in laboratory studies on other species where salt intake is manipulated.  相似文献   

11.
HIROYOSHI HIGUCHI 《Ibis》1989,131(1):94-98
Artificial eggs of six different colours and control eggs of Bush Warblers Cettia diphone were introduced into nests of Bush Warblers, a host of both Little and Himalayan Cuckoos Cuculus poliocephalus and C. saturatw in Japan. All control (chocolate-brown) and artificial red eggs were accepted; all grey and all white eggs were rejected. The rejection rates of orange, pink and orange spots on grey eggs were 8%, 369; and 55%, respectively. Bush arblers are more likely to reject eggs the more dissimilar they are from their own. The results strengthen the possibility that the chocolate-brown eggs of Little and Himalayan Cuckoos may have evolved through the discriminative ability of Bush Warblers and their intolerance towards dissimilar eggs.  相似文献   

12.
Protease inhibitors were used to study certain physiological responses (secretion of the cortical granule protease, altered resceptively to sperm penetration, initiation of cell division and embryogenesis) of sea urchin eggs to stimulation by calcium ionophore A23187. Protease activity in the secretory product released from the eggs 5 min after insemination or parthenogenetic activation with ionophore was completely inhibited by soybean trypsin inhibitor (SBTI), antipain (Ap), and leupeptin (Lp). A barrier was established to prevent subsequently added sperm from penetrating (fertilizing) ionophore-activated eggs, co-incident with the elevation of the fertilization membrane. These processes were retarded by inhibitors of the cortical granule protease in ionophore-activated eggs, just as they are when eggs are initially stimulated by sperm at fertilization. A23187-activated eggs did not divide unless they had been secondarily fertilized by sperm, even if the ionophore was subsequently removed by extensive washing. However, ionophore-activated eggs that were penetrated by a single spermatozoan in SBTI developed into normal larvae under similar conditions. These results suggest that A23187 may be an incomplete parthenogenetic agent because it cannot stimulate eggs to assemble centrioles required to organize the mitotic apparatus. The centrioles are normally provided by the sperm during fertilization. A23187 may also be toxic to the eggs. Furthermore, since cortical granules are secretory organelles, the data suggest a possible functional relationship between calcium ions and protease activation in stimulus-secretion coupling in sea urchin eggs at fertilization.  相似文献   

13.
The nose is the front line defender of the respiratory system and is rich with mechanoreceptors, thermoreceptors, and nerve endings. A time-dependent computational model of transport through nasal models of a healthy human has been used to analyze the fields of physical stresses that may develop at the air-wall interface of the nasal mucosa. Simulations during quiet breathing revealed wall shear stresses as high as 0.3 Pa in the noselike model and 1.5 Pa in the anatomical model. These values are of the same order of those known to exist in uniform large arteries. The distribution of temperature near the nasal wall at peak inspiration is similar to that of wall shear stresses. The lowest temperatures occur in the vicinity of high stresses due to the narrow passageway in these locations. Time and spatial gradients of these stresses may have functional effects on nasal sensation of airflow and may play a role in the well-being of nasal breathing.  相似文献   

14.
M B Constantian 《Plastic and reconstructive surgery》1992,90(3):405-18; discussion 419-20
Grafts to the nasal dorsum and tip, whose local effects are well known, also have distant effects that may not be as readily obvious but that nevertheless are just as real. Dorsal and tip grafts can shorten or lengthen the nose (relatively and absolutely), affect nasal symmetry, preserve or alter nasal ethnic characteristics, and alter dorsum/tip relationships. Each of these properties increases the utility of cartilage and bone grafts in treating a variety of nasal configurations.  相似文献   

15.
Estimates of the temporal and spatial resolution of fossil egg assemblages are required to constrain the inferences that can logically be drawn during assemblage analysis. Consequently, understanding egg transport mechanisms is required before conclusions are developed. Bird eggs are buoyant during part of development and can float from near shore nests during high tides, storm surges, or flooding. Complete and unbroken eggs have survived transoceanic transport. Evidence of these transport processes operating in the past is suggested by the recovery of fossil eggshell in marine deposits. Transport of eggs can potentially confound fossil assemblage spatial analysis since evidence of oceanic transport may not be present on an eggshell when collected. Bird embryos exposed to cold temperatures and immersed in both fresh and salt water can survive from hours to two days, suggesting that oceanic transport of viable eggs is possible, a conclusion further supported by field observations. Eggs of other taxa show similar environmental survival trends and may also be capable of surviving oceanic transport through floatation or rafting. In addition, if viable eggs are transported across seas and hatch, emigration or gene flow of terrestrial egg-laying vertebrates may be possible between landmasses.  相似文献   

16.
Insemination of sea urchin (Arbacia) ova with mussel (Mytilus) sperm has been accomplished by treating eggs with trypsin and suspending the gametes in seawater made alkaline with NaOH. Not all inseminated eggs undergo a cortical granule reaction. Some eggs either elevate what remains of their vitelline layer or demonstrate no cortical modification whatsoever. After its incorporation into the egg, the nucleus of Mytilus sperm undergoes changes which eventually give rise to the formation of a male pronucleus. Concomitant with these transformations, a sperm aster may develop in association with the centrioles brought into the egg with the spermatozoon. Both the male pronucleus and the sperm aster may then migrate centrad to the female pronucleus. Evidence is presented which suggests that fusion of the male pronuclei from Mytilus sperm with female pronuclei from Arbacia eggs may occur, although this was not directly observed. These results demonstrate that Mytilus sperm nuclei are able to react to conditions within Arbacia eggs and differentiate into male pronuclei.  相似文献   

17.
We investigated the contribution of external calcium ions to inositol phosphate-induced exocytosis in sea urchin eggs. We show that: (a) inositol phosphates activate eggs of the sea urchin species Lytechinus pictus and Lytechinus variegatus independently of external calcium ions; (b) the magnitude and duration of the inositol phosphate induced calcium changes are independent of external calcium; (c) in calcium-free seawater, increasing the volume of inositol trisphosphate solution injected decreased the extent of egg activation; (d) eggs in calcium-free sea water are more easily damaged by microinjection; microinjection of larger volumes increased leakage from eggs pre-loaded with fluorescent dye. We conclude that inositol phosphates do not require external calcium ions to activate sea urchin eggs. This is entirely consistent with their role as internal messengers at fertilization. The increased damage caused to eggs in calcium-free seawater injected with large volumes may allow the EGTA present in the seawater to enter the egg and chelate any calcium released by the inositol phosphates. This may explain the discrepancy between this and earlier reports.  相似文献   

18.
Oxygen consumption was found to be essentially the same in unfertilized trout eggs, water activated eggs and eggs immediately after fertilization. Trout eggs are capable of regulating the pH of the surrounding medium probably by releasing buffering electrolytes. The electrolyte composition of the coelomic fluid is close to normal vertebrate blood serum. The coelomic fluid may permit further growth of ovulated eggs before spawning.  相似文献   

19.
Susceptibility of different mouse strains to varying levels of Taenia taeniaeformis eggs has been studied. C3H are shown to be susceptible to any quantity of eggs. However C57 and NMRI are only susceptible to 1–2 eggs, while larvae from an infection of 30–50 eggs are precociously destroyed. Sometimes fertile larvae can also develop in resistant strains of mice infected with some hundred eggs. In C3H the challenge larvae are unable to survive even from an infection given 24–48 h post-first inoculum. The hypothesis is proposed that in resistant strains, infection with 30–50 eggs induces a more rapid immune response which becomes effective while the larva is still vulnerable; in massive infections, however, immune paralysis may occur. Although susceptible strains allow primary infections to develop, they show resistance to challenge infections because larvae are destroyed before they become insusceptible to host attack.  相似文献   

20.
When the vitelline layer of sea urchin eggs (Lytechinus pictus) is disrupted by trypsin or dithiothreitol and the eggs are placed in an isosmotic medium devoid of Ca2+, cytolysis of the eggs occurs. During lysis the entire egg cortex peels off in one piece. Lysis is temperature and pH dependent and is inhibited by cytochalasin B. Cortices from unfertilized eggs contain seven major macromolecular components. A 42K-dalton component is believed to be actin, representing between 12 and 27% of the total protein. Cortices from fertilized eggs may contain between 50 and 65% actin. The actin appears to increase the strength of its attachment to the cortex after fertilization. This method of isolating the entire cortex may be useful for studying structural and enzymatic changes which may occur in the cortex during the cell cycle.  相似文献   

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