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1.
The synthetic glucocorticoid dexamethasone was used to suppress bovine T-lymphocyte function. Dexamethasone-treated animals were challenged with Psoroptes ovis (Hering) to determine if the immunosuppressive treatment would normalize susceptibility to infestation. Dexamethasone suppressed T-lymphocyte function and anti-P. ovis antibody production, and delayed the onset of scab lesions. All animals were not equally susceptible to infestation as a result of dexamethasone treatment. These data further support the importance of anti-P. ovis antibody in colonization of cattle by P. ovis and the pathology associated with scab mite infestation. 相似文献
2.
The sheep biting louse ( Bovicola ovis ) feeds superficially on the skin of sheep but appears to stimulate an immune response. In this study we examined the association between louse infestation and serum and skin surface antibodies. Louse numbers were monitored on experimentally infested Polypay and Columbia ewes for two years and on their lambs in the second year. Serum and skin wash samples were tested for antibodies to soluble extracts of B. ovis , Stomoxys calcitrans and Musca autumnali s by enzyme linked immunosorbent assay (ELISA). In addition, the effects of skin wash extracts on B. ovis were examined in vitro .
The titre of anti- B. ovis antibodies in the serum did not differ significantly between infested and naive ewes. However, there was an increase in serum antibody titre which coincided with periods of high louse density in ewes with high louse counts. Infested lambs had higher serum antibody levels than naive lambs. Substantial cross reactivity was evident among extracts of the different insects.
Densities of lice on the ewes during population decline were negatively related to the titre of skin surface antibodies. Skin washings collected from sheep during B. ovis population decline reduced the number of louse progeny when incorporated into louse diet. These results indicate that B. ovis stimulates an immune response in sheep and suggest that compounds on the skin surface may play a role in the regulation of louse populations. 相似文献
The titre of anti- B. ovis antibodies in the serum did not differ significantly between infested and naive ewes. However, there was an increase in serum antibody titre which coincided with periods of high louse density in ewes with high louse counts. Infested lambs had higher serum antibody levels than naive lambs. Substantial cross reactivity was evident among extracts of the different insects.
Densities of lice on the ewes during population decline were negatively related to the titre of skin surface antibodies. Skin washings collected from sheep during B. ovis population decline reduced the number of louse progeny when incorporated into louse diet. These results indicate that B. ovis stimulates an immune response in sheep and suggest that compounds on the skin surface may play a role in the regulation of louse populations. 相似文献
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Hamilton KA Nisbet AJ Lehane MJ Taylor MA Billingsley PF 《International journal for parasitology》2003,33(8):773-785
Mites are an important group of arthropod pests affecting crops, animals and humans. Despite this, detailed physiological studies on these organisms remain sparse due largely to their small size. Unifying models are required to draw together the diverse information from studies on different groups and species. This paper describes a model for digestion in the parasitic mite, Psoroptes ovis, the causative agent of psoroptic mange or sheep scab disease. The limited information about this species is supplemented with data from other acarines, especially house dust mites and ticks. We review the range of enzymes and allergens found in mites and consider their possible roles in digestion in mites, generally and in particular, P. ovis. Histological studies, enzyme biochemistry and molecular biology and experimental evidence suggest that P. ovis utilises a digestive system reliant upon acid peptidases functioning in a largely intracellular environment. The actions of the digestive enzymes are supplemented by the involvement of bacteria as potential direct and indirect sources of nutrition. It is possible that some extra-corporeal digestion also takes place. The interaction of bacteria and digestive enzymes on the skin surface of the sheep may be responsible for the excessive pathological reactions evident in clinical sheep scab. 相似文献
5.
History, biology and control of sheep scab 总被引:6,自引:0,他引:6
Kirkwood AC 《Parasitology today (Personal ed.)》1986,2(11):302-307
Sheep scab is one of the oldest known diseases of sheep. It is caused by either of the mange mites Psoroptes ovis (Fig. 1 and cover) or Sarcoptes scabiei. P. ovis causes irritation so intense that sheep become preoccupied with scratching, cease to feed and rapidly become emaciated. It should be eradicated on welfare grounds alone (Fig. 2). 相似文献
6.
Berriatua E French NP Broster CE Morgan KL Wall R 《Applied animal behaviour science》2001,71(1):43-55
The relationship between Psoroptes ovis infestation and the nocturnal rubbing and lying behaviour of sheep was examined as part of a longitudinal study of sheep scab. A total of 40 non-infested, scab-na?ve sheep were divided into six groups of between 6 and 20 individuals and each group was subsequently penned with a single infested index case. Multilevel statistical models showed that 75% of the variation in rubbing behaviour could be explained by a combination of three variables: the age of the lesion, the size of the affected area and the time since the introduction of the index case. There were significant differences between sheep in both the baseline level of rubbing activity and the rate at which this behaviour increased over time. Increased rubbing behaviour was associated with reduced total lying times and more interrupted lying behaviour. This work has contributed to our understanding of the role of parasite-induced behavioural changes on welfare and disease transmission. 相似文献
7.
Besides secondary injury at the lesional site, Traumatic brain injury (TBI) can cause a systemic inflammatory response, which may cause damage to initially unaffected organs and potentially further exacerbate the original injury. Here we investigated plasma levels of important inflammatory mediators, oxidative activity of circulating leukocytes, particularly focusing on neutrophils, from TBI subjects and control subjects with general trauma from 6 hours to 2 weeks following injury, comparing with values from uninjured subjects. We observed increased plasma level of inflammatory cytokines/molecules TNF-α, IL-6 and CRP, dramatically increased circulating leukocyte counts and elevated expression of TNF-α and iNOS in circulating leukocytes from TBI patients, which suggests a systemic inflammatory response following TBI. Our data further showed increased free radical production in leukocyte homogenates and elevated expression of key oxidative enzymes iNOS, COX-2 and NADPH oxidase (gp91phox) in circulating leukocytes, indicating an intense induction of oxidative burst following TBI, which is significantly greater than that in control subjects with general trauma. Furthermore, flow cytometry assay proved neutrophils as the largest population in circulation after TBI and showed significantly up-regulated oxidative activity and suppressed phagocytosis rate for circulating neutrophils following brain trauma. It suggests that the highly activated neutrophils might play an important role in the secondary damage, even outside the injured brain. Taken together, the potent systemic inflammatory response induced by TBI, especially the intensively increase oxidative activity of circulating leukocytes, mainly neutrophils, may lead to a systemic damage, dysfunction/damage of bystander tissues/organs and even further exacerbate secondary local damage. Controlling these pathophysiological processes may be a promising therapeutic strategy and will protect unaffected organs and the injured brain from the secondary damage. 相似文献
8.
Selective induction of apoptosis in antigen-presenting cells in mice by Parapoxvirus ovis 总被引:1,自引:0,他引:1
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Viruses have evolved numerous mechanisms to avoid host immune reactions. Here we report a mechanism by which Parapoxvirus ovis (PPVO) interferes with antigen presentation. PPVO (orf virus) causes orf, an acute skin disease of sheep and goats worldwide. Importantly, PPVO can repeatedly infect its host in spite of a vigorous inflammatory and host immune response to the infection. We demonstrate in a mouse system that PPVO induces apoptosis in a significant number of antigen-presenting cells after intraperitoneal injection using the CD95 pathway, thus preventing a primary T-cell response. We also show that PPVO induces a compensatory activation of the immune system. Our results may help to explain the phenomenon that natural PPVO infections in sheep occur repeatedly even after short intervals. They also suggest that the combination of immunosuppressive and immunostimulatory mechanisms is an effective survival strategy that might be used in other viruses as well. 相似文献
9.
Inhibition of neutrophil migration by tumor necrosis factor. Ex vivo and in vivo studies in comparison with in vitro effect 总被引:5,自引:0,他引:5
Y Otsuka K Nagano K Nagano K Hori J Oh-ishi H Hayashi N Watanabe Y Niitsu 《Journal of immunology (Baltimore, Md. : 1950)》1990,145(8):2639-2643
Coincubation of neutrophils with TNF inhibited the chemoattractant-directed migration of neutrophils under agarose and enhanced their migration in the multiwell chemotaxis chamber. To assess the physiological significance of these differing in vitro TNF effects, ex vivo and in vivo investigations were performed using animal models. Neutrophils from the peripheral blood of rabbits preadministered systemic TNF showed impaired ability to migrate toward chemoattractants in vitro. In addition, systemic TNF administration suppressed zymosan-activated plasma-induced local accumulation of leukocytes in mouse skin. The results indicate that circulating TNF may act as a suppressor for local inflammatory reaction. 相似文献
10.
H F Dvorak M E Hammond R B Colvin E J Manseau J Goodwin 《Journal of immunology (Baltimore, Md. : 1950)》1977,118(5):1549-1557
Guinea pigs primed for cutaneous basophil hypersensitivity (CBH) with several soluble proteins or with sheep erythrocytes developed a systemic, delayed-onset, maculopapular rash when challenged parenterally with specific antigen. The rash was most readily induced 5 to 7 days after immunization, at a time when local CBH skin test reactivity was also optimal. Miscroscopically, the rash resembled local CBH skin test reactions, being comprised of a papillary dermal infiltrate of basophils and lymphocytes and a striking dilatation and compaction of superficial venules. In addition to the systemic rash, animals expressing systemic CBH (SCBH) exhibited a striking eosinophilia at 24 hr which gave way to basophilia at 48 hr. Focal collections of eosinophils, and of smaller numbers of basophils, were found in the lungs and spleen; both eosinophils and basophils infiltrated the medulla of the thymus. Thus, basophil-rich infiltrations are favored in the skin even after systemic challenge with antigen and occur only to a much smaller extent in other organs where eosinophils may predominate. These differences in the response of various organs to challenge with parenteral antigen suggest that as yet unidentified local factors play a determinative role in regulating the inflammatory response. The pathogenesis of SCBH is not yet established, but it shares many of the properties of local CBH: histology, carrier specificity, development early after sensitization in the absence of detectable antibodies. Passive transfer has not been accomplished with serum alone but has been achieved irregularly with cells plus serum. SCBH may serve as a useful model for several disease states in man characterized by a systemic rash and eosinophilia, including certain types of drug reaction. 相似文献
11.
A scanning electron microscope (SEM) study of the mouthparts of Psoroptes cuniculi from rabbits and P. ovis from sheep established that they are identical in morphology and are adapted for surface feeding rather than piercing the epidermis. Haemoglobin was found in both P. cuniculi and P. ovis on rabbits but not in P. ovis on sheep and it is concluded that the haemoglobin is derived from small haemorrhages on the surface of inflamed rabbit skin. This inflammation is caused by the deposition of antigenic material on the skin which is abraded by the mite mouthparts. The mites feed on the resulting exudate and on other surface material. An immunofluorescent assay revealed that the 2 mite species are antigenically similar. 相似文献
12.
Dono M Bertonati MR Poggi R Teneggi E Maddalo F Via F Orlandi R Maroli M Roncella S Fedeli F Battolla E 《The new microbiologica》2005,28(4):365-368
Human infection with the sheep nasal botfly Oestrus ovis is sporadic and is often the consequence of an accidental deposit of the larvae by an adult botfly in the eye. This infestation results in external ophthalmomyiasis that, although a very rare condition, is more common among people living close to farming communities. We report three cases of O. ovis infestation which occurred in Italy in a limited area of La Spezia province (Le Cinque Terre), Italy during summer 2004. None of the patients had contact with wild or farm animals. 相似文献
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Slaughterhouse surveys to determine the prevalence and intensity of larval Oestrus ovis Linnaeus (Diptera: Oestridae) in sheep, were conducted monthly for 1 year in Konya, Turkey. A total of 624 sheep, selected at random, were examined and 59% were found to be infested by O. ovis. A total of 8801 larvae were collected, of which 68.9% were first-stage, 19.1% second-stage and 12% third-stage larvae. All three larval stadia were seen in each month of the year. The larval intensity for infected sheep was 23.9, with 16.48 L(1), 4.55 L(2) and 2.87 L(3). The monthly prevalence ranged from 34.6% in January to 76.9% in October. The largest number of larvae (180) was obtained from a sheep in August (122 L(1), 52 L(2) and 6 L(3)). The infestation rate was higher in 4 - 6-year-old sheep, at 72.6%. The infestation rates were 64.4% in female and 47.5% in male sheep. 相似文献
15.
A serodiagnostic test for the diagnosis of infestation by the sheep nasal bot fly, Oestrus ovis (Linné) was examined. The enzyme-linked immunosorbent assay (ELISA) technique was used to analyze and compare the production of immunoglobulin G (IgG) antibodies against excretory-secretory products (ESP) and crude extract (CE) antigens from all the different larval stages of O. ovis in the sera of 276 adult sheep sampled in summer (n = 135) and winter (n = 141). ESP from first stage larvae was the most sensitive, coating antigen in winter and ESP from second stage larvae during summer. The most specific values were obtained by ESP against L1 in winter and by CE against L3 in summer. These results show that the stage of larval development has a significant impact on the humoral immune response over the course of a season. A significant correlation (P < 0.001) was found between the number of O. ovis larvae and the serum antibody levels using all differents antigens, except L3 CE. In Spain, where a long favourable period exists for the evolution and development of the different stage larvae between March and November, the ELISA test using L1 ESP antigen during winter and L2 ESP antigen in summer may be used for ovine oestrosis immunodiagnosis. 相似文献
16.
P J James 《International journal for parasitology》1999,29(6):869-875
Alternatives to chemicals for controlling parasites are required to minimise problems from resistance, residues in animal products and occupational exposure. Utilisation of host response to parasites through selection of resistant types or vaccination is an appealing option. To date most studies have been with haematophagous or invasive parasites which directly contact elements of the host immune system. Sheep lice (Bovicola ovis) feed superficially on the skin of sheep ingesting lipid, scurf, bacteria and loose stratum corneum squames. Evidence is presented that despite their surface feeding habit Bovicola ovis stimulate an immune response in sheep and that this response may play a part in regulating the size of louse populations. 相似文献
17.
Inhibitory effect of PACAP-38 on acute neurogenic and non-neurogenic inflammatory processes in the rat 总被引:1,自引:0,他引:1
Helyes Z Pozsgai G Börzsei R Németh J Bagoly T Márk L Pintér E Tóth G Elekes K Szolcsányi J Reglodi D 《Peptides》2007,28(9):1847-1855
Inhibitory actions of pituitary adenylate cyclase activating polypeptide (PACAP) have been described on cellular/vascular inflammatory components, but there are few data concerning its role in neurogenic inflammation. In this study we measured PACAP-like immunoreactivity with radioimmunoassay in the rat plasma and showed a two-fold elevation in response to systemic stimulation of capsaicin-sensitive sensory nerves by resiniferatoxin, but not after local excitation of cutaneous afferents. Neurogenic plasma extravasation in the plantar skin induced by intraplantar capsaicin or resiniferatoxin, as well as carrageenan-induced paw edema were significantly diminished by intraperitoneal PACAP-38. In summary, these results demonstrate that PACAP is released from activated capsaicin-sensitive afferents into the systemic circulation. It diminishes acute pure neurogenic and mixed-type inflammatory reactions via inhibiting pro-inflammatory mediator release and/or by acting at post-junctional targets on the vascular endothelium. 相似文献
18.
V K Nguyen P Jacquiet C Duranton J P Bergeaud F Prevot P Dorchies 《Parasite (Paris, France)》1999,6(2):141-149
OEstrosis is a very common myiasis of sheep and goats in mediterranean and tropical countries. Goats are suitable hosts for OEstrus ovis but the parasitic burden remain lower than in sheep. Cellular responses (mucous and serous mast cells, eosinophis and globules leucocytes) were measured in 30 infected and 30 non infected sheep and in 23 infected and 24 non infected goats. The presence of OEstrus ovis larvae led to an important inflammatory response in sheep and in goats as well. Furthermore, the intensity of the cellular response correlated with the larva burden, specially with globules leucocytes and eosinophils. Nevertheless, huge differences occurred between sheep and goats responses even in similar larval burden range. Infected sheep showed larger counts of mucous mast cells than goats, the differences were smaller in serous mast cells and eosinophils and no difference was detected in globules leucocytes (intraepithelial mast cells) counts between the two hosts species. These results were compared with those obtained in gastro-intestinal strongyles infections. 相似文献
19.
Laggner U Di Meglio P Perera GK Hundhausen C Lacy KE Ali N Smith CH Hayday AC Nickoloff BJ Nestle FO 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(5):2783-2793
γδ T cells mediate rapid tissue responses in murine skin and participate in cutaneous immune regulation including protection against cancer. The role of human γδ cells in cutaneous homeostasis and pathology is characterized poorly. In this study, we show in vivo evidence that human blood contains a distinct subset of proinflammatory cutaneous lymphocyte Ag and CCR6-positive Vγ9Vδ2 T cells, which is rapidly recruited into perturbed human skin. Vγ9Vδ2 T cells produced an array of proinflammatory mediators including IL-17A and activated keratinocytes in a TNF-α- and IFN-γ-dependent manner. Examination of the common inflammatory skin disease psoriasis revealed a striking reduction of circulating Vγ9Vδ2 T cells in psoriasis patients compared with healthy controls and atopic dermatitis patients. Decreased numbers of circulating Vγ9Vδ2 T cells normalized after successful treatment with psoriasis-targeted therapy. Taken together with the increased presence of Vγ9Vδ2 T cells in psoriatic skin, these data indicate redistribution of Vγ9Vδ2 T cells from the blood to the skin compartment in psoriasis. In summary, we report a novel human proinflammatory γδ T cell involved in skin immune surveillance with immediate response characteristics and with potential clinical relevance in inflammatory skin disease. 相似文献
20.
J L Zaugg 《Journal of wildlife diseases》1987,23(2):205-210
Anaplasma ovis was experimentally transmitted from sheep to pronghorn antelope (Antilocapra americana) and back to sheep. Anaplasma ovis was recovered in splenectomized sheep, from two of three spleen-intact pronghorns following their inoculation with blood from known A. ovis carrier sheep. These two pronghorns exhibited a 0.5% or higher A. ovis parasitemia within 48 days after exposure, and an anaplasmosis-positive serological response 91 days after exposure. Clinical signs of illness were not observed. Blood from the infected pronghorns produced disease in four splenectomized sheep. 相似文献