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1.
Tracheal and conjunctival infections with Cryptosporidium were established in pigs by inoculation of oocysts into the trachea and onto the conjunctival sacs. The protozoa were found attached to epithelial cells by an electron-dense band and a folded, vacuolated feeder organelle. They were situated in a parasitophorous vacuole surrounded by a double-layered membrane covered by glycocalyx. Trophozoites, schizonts, merozoites, macrogameters and oocysts could be demonstrated. In addition to normal stages of the life-cycle, degenerate stages were found.The infections with Cryptosporidium were characterized by focal destruction and loss of epithelial cells. Numerous intraepithelial lymphocytes were associated with affected foci, as were infiltrations with lymphocytes, monocytes, and macrophages.  相似文献   

2.
Tagging and elimination of plasmids in Salmonella of avian origin   总被引:2,自引:0,他引:2  
This study compared the effectiveness of a number of procedures designed to label and eliminate plasmids that may play a role in virulence in Salmonella. Twenty strains of Salmonella of 9 serovars were subjected to 3 methods for labelling plasmids with transposons. Strains containing labelled and unlabelled plasmids were exposed to physical and chemical curing agents. Plasmids in 9 of 20 strains of Salmonella were tagged by conjugation with a donor Escherichia coli containing a temperature-sensitive RP4 plasmid that carried the Tn1 transposon. Plasmids in 2 of 5 strains of Salmonella were labelled by conjugation with a donor E. coli that contained a F' tslac::Tn5 plasmid. Transduction of Salmonella with a P22 bacteriophage that carried a temperature-sensitive Tn10 transposon resulted in chromosomal insertion of Tn10 in 2 of 10 strains. Use of chemical curing agents resulted in curing of plasmids in only 6 of 17 strains. Two strains were cured by ethidium bromide, two by a combination of ethidium bromide and novobiocin, two by a combination of imipramine and methylene blue, and none by acridine orange, novobiocin, sodium dodecyl sulfate or rifampicin. In contrast, plasmids in 14 of 17 Salmonella strains were eliminated by incubation at 45.5 degrees C.  相似文献   

3.
Two methods to preserve gastrointestinal tract (GIT) organs and tissues, plastic coating (PC) and plastination (PN), were investigated and compared. Specimens to be preserved were removed from animals within 2 h of death and immediately cleaned with water. Digesta contents were removed by flushing desired portions of GIT with water until the exiting water was clear. In the PC method, cleaned specimens were dehydrated by immersion in an isopropanol solution, dried with forced air after positioning and orientation as in situ, and finally coated on the outer and inner surfaces with a clear plastic material. In the PN procedure, specimens were filled with, and submerged in, a low-formaldehyde fixative, then dehydrated by immersion in a cold acetone solution. Dehydrated specimens were immersed in silicone and placed in a freeze drier for impregnation under low vacuum, followed by overnight gas curing with a silicone crosslinker. Finally, viewing windows were cut out with a scalpel in GIT preserved by both methods. Preserved GIT and tissues had an appearance similar to their appearance in vivo. The PC method was simple and inexpensive. Plastinated specimens were more flexible, durable, and lifelike than those preserved by the PC method. In addition, many body parts, such as muscles, nerves, bones, ligaments, and central nervous system specimens, were preserved by PN. Both methods were found to be useful tools for postmortem studies of tissues and GIT organs.  相似文献   

4.
The effect of bovine mammary secretion during the early nonlactating period and of antibiotic preparations on bovine polymorphonuclear neutrophil (PMN) phagocytic function and morphology were evaluated in a series of in vitro multifactorial experiments. Benzathine cloxacillin (CL), benzathine cephapirin (CE), sodium novobiocin (NO), and a combination of dihydrostreptomycin with procaine penicillin G (DP) were prepared in the presence and absence of a peanut oil aluminum monostearate vehicle. The PMN were isolated from bovine blood, and the effect of each antibiotic preparation on PMN function and morphology was evaluated in a buffer, fat, skin, and a combination of fat with skim from bovine mammary secretion during the nonlactating period. The fat and skim were diluted with buffer to approximate their concentration in mammary secretion. Phagocytic functions of PMN were monitored by fluorescent microscopy, which made it possible to estimate both ingestion and intracellular killing of bacteria by PMN. Changes in PMN morphology were monitored by transmission electron microscopy. The ability of PMN to ingest and kill Staphylococcus aureus ATCC 25923 was significantly decreased by fat, skim, CL, CE, NO, and DP. Effects of some antibiotics on ingestion and killing of bacteria by PMN were influenced by the addition of vehicle and by interactions with mammary secretion. Neutrophil morphology was altered by fat, skim, CL, CE, NO, and DP. The detrimental effects of CL, CE, NO, and DP on PMN morphology were influenced (some significantly) by the presence of vehicle and interactions with mammary secretion. There were significant correlations among secretion- and antibiotic-induced changes in PMN ingestion of bacteria, PMN killing of bacteria, and PMN morphology.  相似文献   

5.
The efficacy, tolerance and ease of administration of a nutraceutical, carprofen or meloxicam were evaluated in a prospective, double-blind study on 71 dogs with osteoarthritis. The client-owned dogs were randomly assigned to one of the three treatments or to a placebo control group. The influence of osteoarthritis on the dogs' gait was described by comparing the ground reaction forces of the arthritic dogs and 10 normal dogs. Before the treatments began, and 30 and 60 days later, measurements were made of haematological and biochemical variables and of the ground reaction forces of the arthritic limb, and subjective assessments were made by the owners and by the orthopaedic surgeons. Changes in the ground reaction forces were specific to the arthritic joint, and were significantly improved by carprofen and meloxicam but not by the nutraceutical; the values returned to normal only with meloxicam. The orthopaedic surgeons assessed that there had been an improvement with carprofen and meloxicam, but the owners considered that there had been an improvement only with meloxicam. The blood and faecal analyses did not reveal any changes. The treatments were well tolerated, except for a case of hepatopathy in a dog treated with carprofen.  相似文献   

6.
为体外培养纯化出稳定的奶牛乳腺上皮细胞和成纤维细胞,试验通过外科手术的方法取妊娠后期或泌乳期的荷斯坦奶牛乳腺组织,分离乳腺腺泡,用组织块法体外培养奶牛乳腺细胞,应用差时胰酶消化法和差速贴壁法将奶牛乳腺上皮细胞和成纤维细胞分别纯化出来,并用免疫组化的方法对细胞的纯度进行鉴定。结果表明:纯化的奶牛乳腺上皮细胞多为多角形,细胞核呈圆形或椭圆形,核仁清晰可见,多呈鹅卵石样或铺路石样生长,并可分泌乳滴,角蛋白-18反应阳性,波形蛋白反应阴性;纯化的奶牛乳腺成纤维细胞多为长梭形,呈旋涡状或放射状生长,角蛋白-18反应阴性,波形蛋白反应阳性;经纯化后2种细胞的纯度均可达95%以上,可满足后续试验的要求。  相似文献   

7.
The effects of viral vaccinations and immunization with sheep red blood cells (SRBC) on the humoral response of pullets were investigated. Pullets were vaccinated with Marek's disease virus, Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and infectious bursal disease virus at appropriate ages used in commercial practice. At seven weeks, the pullets were intramuscularly immunized with SRBC. NDV and IBV antibodies were detected by hemagglutination-inhibition tests. Hemagglutination (HA) titers were established against SRBC. IBV antibody titers were not affected by vaccination or by immunization with SRBC. NDV antibody titers were significantly increased by vaccination and by immunization with SRBC. The SRBC agglutinin response was also positively affected by vaccination. The HA titer increase consisted of a rise in 2-mercaptoethanol (2-ME)-sensitive antibodies and a fall in 2-ME-resistant antibodies.  相似文献   

8.
The effects of concurrent cage contamination with Salmonella typhimurium and Eimeria tenella on the establishment of salmonella infection in day-old chickens were investigated. Chickens were divided into five groups: uninfected recipient birds placed in a cage contaminated by donor birds infected with E. tenella and S. typhimurium; E. tenella-infected recipients placed in a cage contaminated by S. typhimurium-infected donors; uninfected recipients placed in a cage contaminated by S. typhimurium-infected donors; E. tenella-infected recipients placed in a cage contaminated by uninfected donors; and uninfected recipients placed in a cage contaminated by uninfected donors. Three identical trials were conducted. Recipient birds were necropsied 4, 7, and 11 days after caging. In the cage where donor birds infected with both organisms had been reared, S. typhimurium counts in feces and number of feces positive for S. typhimurium were significantly (P less than 0.05) greater than those in the other cages on days 0, 4, and 7 after caging. Moreover, in this cage, more chicks died, counts of S. typhimurium in cecal contents were greater, and more birds were positive for S. typhimurium than in the other groups. This suggests that S. typhimurium infection in day-old chickens is enhanced in cages contaminated with E. tenella and S. typhimurium compared with infection in cages contaminated with S. typhimurium alone.  相似文献   

9.
10.
OBJECTIVES: To evaluate the tear film qualitatively and conjunctival goblet cell numbers in cats with and without corneal sequestra. ANIMALS STUDIED AND PROCEDURES: This was a prospective evaluation of 11 cats with corneal sequestra and 14 control eyes that were either the contralateral normal eye when the sequestrum was unilateral or from control cats of similar age with no ocular disease. All cats in this study were examined by a veterinary ophthalmologist. The ophthalmic examinations included a neuro-ophthalmic evaluation, Schirmer tear tests, fluorescein staining, tear film break-up times, applanation tonometry, biomicroscopy, and indirect ophthalmoscopy. The palpebral conjunctiva at the dorsal nasal, ventral nasal, dorsal temporal and ventral temporal fornices were biopsied after topical anesthetic was applied to the cornea and conjunctiva. The conjunctival biopsies were fixed in formalin and sectioned routinely and stained with hematoxylin and eosin, and periodic acid-Schiff. These slides were examined by light microscopy by a blinded examiner. Goblet cell numbers were compared to conjunctival basal epithelial cell numbers by region. The goblet cell numbers by region from the eyes with sequestra was statistically compared to those from eyes without sequestra, with a student's paired t-test. Conjunctival swabs were collected from the cats with corneal sequestra and submitted for polymerase chain reaction for Herpes felis, Chlamydia psiitticia, and Mycoplasma felis. The corneal sequestra were removed by surgical keratectomy and fixed and stained routinely, and examined by light microscopy. RESULTS: No neurologic abnormalities were detected in any of the cats. The Schirmer tear tests (eyes with sequestra 14+/-5.1 mm/min; normal eyes 15+/-6.8 mm/min) and intraocular pressures (eyes with sequestra 21+/-6.6; normal eyes 22+/-5.8) were within normal reference ranges for cats. Biomicroscopic examinations revealed varied sizes and depths of brown- and amber-colored corneal sequestra. No abnormalities were noted on indirect ophthalmoscopic examinations. The tear film break-up time was 21 s (+/-12) for the normal eyes (n=14) and 14 s (+/-13) in eyes with corneal sequestra (n=11). The average goblet/epithelial cell ratios by region for the normal eyes and the eyes with sequestra respectively were 0.66, 0.56 for the dorsal nasal fornix, 0.68, 0.57 for the ventral nasal fornix, 0.63, 0.48 for the temporal dorsal fornix, and 0.55, 0.49 for the temporal ventral fornix. There were no significant differences in tear film break-up times and goblet cell numbers in eyes with corneal sequestra and those without sequestra. Three conjunctival swabs from two of 11 cats with sequestra were positive with PCR for Herpes felis virus. These included one cat with bilateral sequestra and one cat with unilateral corneal sequestrum. CONCLUSIONS: The pathogenesis of feline corneal sequestra does not appear to be linked primarily to abnormal goblet cell numbers, qualitative tear film abnormalities, and accelerated tear film break-up time.  相似文献   

11.
Traumatic injuries are common in horses and may be caused by self-infliction, accident or in an increasing number by an act of violence. Over a four year period, 193 horses with injuries caused by self-infliction or accident were referred to the clinic. In addition, ten horses with injuries associated with an act of violence had to be treated. Those injuries were caused by gunshots, or were stab wounds caused by spear like instruments or knives. Furthermore, cases of zoophilism and zoosadism were observed. Penetrating injuries were potentially life-threatening and in particular injuries with soft tissue damage extending over the limits of visible injury required a special approach. Of the ten horses, seven survived by surgical or medical treatment. Beside of medical aspects, forensic aspects should be considered in such cases.  相似文献   

12.
Archived formalin-fixed, paraffin-embedded tissues from 25 pigs naturally infected with transmissible gastroenteritis virus (TGEV) were examined by in situ hybridization for TGEV nucleic acid using a nonradioactive digoxigenin-labeled cDNA probe that targeted the nucleocapsid sequence of TGEV strains. The results of in situ hybridization for the detection of TGEV were compared with virus isolation (VI), a fluorescent antibody test (FAT), and transmission electron microscopy (TEM). VI, FAT, and TEM were tested over a course of time before the in situ hybridization was performed. Positive hybridization signals were detected in duodenal, jejunal, and ileal enterocytes from 21 pigs. Hybridization signals were confined to the cytoplasm. Intestinal specimens from 25 piglets were evaluated by 4 tests. Twenty-one of 25 were positive by in situ hybridization. Of these 21 samples, 5 (24%) were positive for TGEV by all 4 tests, 15 (71%) were positive by FAT, 14 (67%) were positive by VI, and 6 (29%) were positive by TEM. In situ hybridization for the detection of TGEV in formalin-fixed, paraffin-embedded tissues provides a rapid means of confirmation of a histopathological diagnosis of TGEV without virus isolation, or when only formalin-fixed intestinal specimens were available.  相似文献   

13.
14.
Saline extracts of logarithmic-phase Pasteurella haemolytica, serotype 1, were separated by chromatofocusing. The resulting fractions were analyzed by immunodiffusion and an enzyme-linked immunosorbant assay, and six antigen groups (AG's) were identified. AG 1 did not bind to the column, AG's 2, 3 and 4 were eluted with a decreasing pH gradient, and AG's 5 and 6 were eluted with an increasing NaC1 gradient. Fractions containing each AG were pooled and further purified by gel filtration. The AG's were subsequently characterized as to protein, carbohydrate and 2-keto-3-deoxyoctanate (KDO) content. AG's 1, 5, and 6 had higher carbohydrate contents than AG's 2, 3 and 4. Only AG 5 contained detectable levels of KDO. The AG's were also analyzed by SDS-PAGE and immunoblotting. Each AG produced a characteristic pattern of proteins and antigens, although two antigenic proteins were common to all AG's. AG 1 contained the greatest number of antigenic proteins. Immunization of mice with each AG in Freund's incomplete adjuvant resulted in a strong antibody response to the homologous AG for four of the six AG's. Limited protection against a P. haemolytica challenge was observed in mice that were immunized with AG 2 or 4.  相似文献   

15.
Neospora caninum is widely distributed in the world and this parasite is one of the major causes of abortion in cattle. Dogs and coyotes are definitive hosts of N. caninum and several species of domestic and wild animals are intermediate hosts. Dogs can become infected by the ingestion of tissues containing cysts and then excrete oocysts. It is not yet known whether sporulated oocysts are able to induce a patent infection in dogs, i.e. a shedding of N. caninum oocysts in feces. The objective of this study was to experimentally examine the infection of dogs by sporulated oocysts. The oocysts used in the experiment were obtained by feeding dogs with brain of buffaloes (Bubalus bubalis) positive for anti-N. caninum antibodies by indirect fluorescent antibody test (IFAT ≥200). Oocysts shed by these dogs were confirmed to be N. caninum by molecular methods and by bioassay in gerbils, and sporulated N. caninum oocysts were used for the oral infection of four dogs. The dogs were 8 weeks old and negative for antibodies to N. caninum and Toxoplasma gondii. Dogs 1 and 4 received an inoculum of 10,000 sporulated oocysts each; dog 2 an inoculum of 5000 sporulated oocysts and dog 3 received 1000 sporulated oocysts of N. caninum. The total feces excreted by these dogs were collected and examined daily for a period of 30 days. No oocysts were found in their feces. The dogs were monitored monthly for a 6-month period to observe a possible seroconversion and when this occurred the animals were eliminated from the experiment. Dogs 1 and 4 seroconverted 1 month after the infection with titer, in the IFAT, of 1600 and 800, respectively; the other two dogs presented no seroconvertion during the 6-month period. Dogs 1 and 2 were euthanized 180 days after infection and were examined for the detection of N. caninum in tissues (brain, muscle, lymph node, liver, lung, heart and bone marrow) by immunohistochemistry and PCR with negative results in both techniques. Bioassay in gerbils with brain of these dogs was also performed and again the results were negative. In conclusion, dogs infected with sporulated oocysts of N. caninum were not able to shed oocysts in feces. However, a higher dose of infection stimulated the production of antibodies against N. caninum in the dogs.  相似文献   

16.
To evaluate the effect of diet on results obtained by use of 2 commercial test kits for detection of occult blood in feces, 5 dogs were fed 7 diets in randomized sequence. Dry and canned diets with various principal ingredients were evaluated. Each diet was offered twice over a 24-hour period, followed by a 36-hour nonfeeding period. Fecal specimens were collected twice daily, and tests for occult blood were performed within 12 hours. The dietary origin of fecal specimens was confirmed by use of colored markers fed with each diet, and was correlated with estimates of gastrointestinal tract transit time. A modified guaiac paper test and an o-tolidine tablet test were performed on each specimen. Of 59 specimens, 4 were positive for occult blood, using the o-tolidine tablet test. Three positive results were associated with a mutton-based canned diet, and 1 positive result was associated with a canned beef-based diet. Of 59 specimens, 11 were positive for occult blood, using the modified guaiac paper test. Four positive results were associated with the mutton diet, and 3 positive results were associated with the beef diet. Of the remaining 5 diets, 4 caused 1 positive reaction. Results were inconsistent with the null hypothesis that the distribution of positive occult blood test results is not affected by diet (P < 0.025), and indicate that diet can affect the specificity of peroxidase-based tests for detection of occult blood in canine feces. Diet modification prior to testing is recommended.  相似文献   

17.
旨在探讨体外分离培养牛肺泡上皮细胞(bovine alveolar epithelial cells,BAECs)的方法及Wnt5a对牛结核分枝杆菌卡介苗(bacille Calmette-Guérin,BCG)感染BAECs细胞自噬的调控机制。试验选用酶联合消化法和机械刮刷法分离细胞,差速贴壁法纯化BAECs,免疫荧光染色检测上皮细胞标志物角蛋白14(cytokeratin 14,CK14)和角蛋白5(cytokeratin 5,CK5)的表达;BCG感染BAECs,并用Box-5抑制Wnt5a的表达,Western blot和免疫荧光染色检测自噬相关蛋白及非经典Wnt信号通路相关蛋白的表达。结果表明,采用酶联合消化法和机械刮刷法能够成功分离纯度较高的BAECs,细胞经CK14和CK5鉴定为阳性;BCG感染BAECs促进Wnt5a表达,增加细胞自噬,Box-5预处理下调BCG诱导的细胞自噬相关蛋白LC3II、P62、Atg7及Atg5的表达,且抑制非经典Wnt/Ca2+信号通路相关蛋白Wnt5a、CaMKII及NFAT的表达。综上,试验成功建立BAECs分离培养方法,BCG感染增加BAECs内Wnt5a表达和细胞自噬,抑制Wnt5a下调BCG诱导的BAECs细胞自噬,且Wnt5a是通过非经典Wnt/Ca2+信号通路调控BCG诱导的BAECs细胞自噬。  相似文献   

18.
Sixteen sera from 17 dogs with blastomycosis produced a precipitin band identical with the diagnostically significant precipitin A band formed by a Blastomyces dermatitidis reference antiserum and a soluble B dermatitidis yeast-form antigen in the agar-gel immunodiffusion test (94% sensitivity). The other serum from a dog with histopathologic demonstration of B dermatitidis in pulmonic tissues produced an unrelated precipitin band. Sixteen of the 17 diagnoses made by the detection of precipitin A were confirmed by isolation and culture of B dermatitidis or by histopathologic demonstration of the pathogen. Three cases were confirmed by cultural isolation only, 10 by histopathologic demonstration only, and 3 by both. In three other dogs given amphotericin B, there were demonstrable changes in serum precipitin A reactions.  相似文献   

19.
新型接枝β-环糊精蚕丝芳香纤维的研究   总被引:6,自引:1,他引:5  
为开发新型蚕丝功能纤维,设计并合成了具有包合能力的接枝环糊精蚕丝芳香纤维。首先以邻碘酰基苯甲酸为氧化剂合成了6位环糊精单醛,然后在弱酸性的条件下将其通过还原氨化反应接枝到蚕丝纤维上,并用来包合芳香物质。结果表明,环糊精单醛与蚕丝纤维的质量比为2∶1、pH 6.2、反应时间为7 d,其接枝效果较好。获得的功能纤维具有良好的包合能力,包合芳香物质后得到的芳香纤维,能长久保持香味。  相似文献   

20.
A procedure was developed for separating antigens associated with a saline extract of Pasteurella haemolytica serotype 1. Seven antigens were identified by immunoelectrophoresis to be associated with the extract. The extract was subjected to preparative isoelectrofocusing in a pH range of 3-10. The majority of extracted proteins were found to have pI's of 4-6, whereas the carbohydrate antigen(s) were distributed over a pI range of 3.0-8.0. The fractions that were of interest were pooled and refocused in a narrower pH range to improve resolution of the protein antigens. Specific antigens from defined pH ranges were pooled to form 6 antigen groups. These antigen groups were examined further by immunoelectrophoresis, analytical isoelectrofocusing, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The molecular weights of the proteins found in the capsular extracts ranged from 33 k to greater than 80 k. Injection of mice with capsular extract or antigen Groups 1-6 in Freund's incomplete adjuvant resulted in a serum antibody response to the various antigens as detected by an enzyme-linked immunosorbent assay. Significant protection (P less than 0.05) against challenge with virulent P. haemolytica was seen in mice injected with antigen Groups 2 and 4. Six calves were immunized with saline extract. These calves had greater resistance to experimental pneumonic pasteurellosis than did 6 non-vaccinated calves. A serum antibody response to the crude extract and to each antigen group was detected in vaccinated calves by an enzyme-linked immunosorbant assay.  相似文献   

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