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1.
Parvaquone (BW993C), 2-cyclohexyl-3-hydroxy-1,4-naphthoquinone, and buparvaquone (BW720C) 2-(trans-4-t-butylcyclohexyl-methyl)-3-hydroxy-1,4-naphthoquinone, were evaluated to determine their therapeutic efficacy in the treatment of theileriosis caused by Theileria annulata infection in cattle in Iran. One hundred and fifty-nine pure and crossbred Bos taurus cattle, experimentally or naturally infected with T annulata, were treated. Parvaquone was injected into 86 animals with up to three doses of 20 mg kg-1 or 10 mg kg-1 at intervals of 48 hours between doses. Buparvaquone was injected into 73 animals. Up to three doses of 2.5 mg kg-1 were injected with an interval of 48 hours between doses. The recovery rate of animals treated with parvaquone was 60.7 per cent and with buparvaquone it was 88.7 per cent. No significant side effects of relapse of disease were observed following the use of either compound. It is concluded that buparvaquone at a dose of 2.5 mg kg-1 has a satisfactory therapeutic index and is a more effective treatment of T annulata infection than parvaquone. The prophylactic use of schizont tissue culture vaccine and chemotherapy with buparvaquone could be the most promising means of controlling theileriosis in Iran.  相似文献   

2.
Theileriosis is an economically important haemoprotozoal disease with high morbidity and mortality in cattle. Buparvaquone is very effective in the treatment of Theileria infections in cattle. The present study reported an outbreak of bovine tropical theileriosis in Fars Province, southern Iran with buparvaquone treatment failure associated with mutations in drug-binding sites of its causative agent. The infected animals (n=8) exhibited poor condition, fever, anemia, rough coat and superficial lymph node enlargement. Both blood smears and lymph nodes punctures were positive and further molecular examination revealed that these animals were infected with Theileria annulata. Death occurred in seven of the eight infected animals in spite of the buparvaquone treatment. At molecular study, two types of important single-base mutations were observed in the cytochrome b gene of the parasite. These changes resulted in amino acid mutations in the parasite cytochrome b from serine (AGT) 109 to glycine (GGT) for the six dead cases and proline (CCT) 233 to serine (TCT) for one dead case within strongly Q(o) drug-binding sites. In contrast, neither of these mutations was found in the parasite cytochrome b for the buvarvaquone-treated animal. It seems that these mutation sites are associated with resistance to buparvaquone, a hydroxynaphthoquinone compound.  相似文献   

3.
Levels of vitamins A and E, beta carotene and lipid peroxidation product (TBARS) were determined in plasma and cervical mucus of 32 cows. Red blood cell (RBC) reduced glutathione (GSH) and RBC glutathione peroxidase (GSH-Px) activity as well as vitamin C plasma levels were measured. After taking cervical mucus and blood samples the animals were inseminated artificially. Three month later pregnant (n = 20) and non pregnant (n = 12) cattle were determined. Correlations between investigated parameters and pregnancy rate were performed. In blood plasma, a significant correlation was observed between vitamin A and beta carotene (P < 0.001) as well as vitamin E (P < 0.05). There was a significant (P < 0.001) correlation in TBARS values of plasma and cervical mucus. However, none of the investigated parameters showed a significant difference between pregnant and non pregnant cows. In conclusion, we did not find any difference and correlation between pregnant and nonpregnant animals concerning the investigated antioxidants. A positive correlation was observed between lipid peroxidation levels of plasma and cervical mucus. Our work provides basic informations about antioxidative parameters under physiological conditions. Further studies should investigate possible correlation between disturbed fertility and antioxidative status of plasma and cervical mucus in clinically healthy cows.  相似文献   

4.
The antitheilerial activity of buparvaquone (BW 720C) was evaluated in experimentally induced Theileria annulata infections in cross-bred male calves. T. annulata infections were induced by injecting a suspension of infected ground tick tissue suspension (GUTTS) equivalent to two ticks subcutaneously into each calf. Buparvaquone at a dose of 2.5 mg kg-1 body weight was given as a single injection (intramuscularly) on Day 0 (Group 1), Day 8 (Group 2) and Day 12 (Group 3) post-infection. The animals in Groups 4 and 5 were untreated and challenged controls, respectively. All of the recovered animals from Groups 1-4 were challenged with a lethal dose of T. annulata at 6 weeks post-infection. The immunized animals were resistant to the homologous challenge, which killed three of four control animals (Group 5); the controls showed typical antemortem and post-mortem lesions of theileriosis.  相似文献   

5.
Buparvaquone, a naphthoquinone with known efficacy against Theileria parva parva in cattle, was tested for activity against Theileria cervi piroplasms in both an in vitro culture system and in vivo in experimentally infected white-tailed deer. The in vitro data showed a significant decrease in the incorporation of 3H-hypoxanthine by infected red blood cells treated with buparvaquone when compared to that seen with imidocarb and chloroquine treatment. In both intact and splenectomized deer treated with buparvaquone (2.5 mg kg-1) a gradual decrease in piroplasm parasitaemia was observed following treatment. However, in the splenectomized deer, parasitaemia levels returned to near pretreatment values after approximately 2 weeks.  相似文献   

6.
Attempts (some successful) were made to eliminate Theileria buffeli infections from 23 naturally or experimentally infected, splenectomised calves. The anti-theilerial hydroxynaphthoquinone derivative buparvaquone was used either alone or in combination with primaquine phosphate. After treatment the calves were monitored for infection for up to 26 weeks. Blood films were examined for piroplasms and serum antibody levels were measured using an immunofluorescence technique. Buparvaquone alone failed to eliminate infections. Infections were eliminated from 11 of 16 calves treated twice with buparvaquone and three or six times with primaquine phosphate. Theilerial parasites were not subsequently seen in these 11 calves nor were antibodies detected beyond the eighth week after treatment.  相似文献   

7.
Deficiencies of vitamins A, D, K, E and thiamin can cause severe limitations in beef production. In particular, vitamin A and E can be common causes of lost profit, secondary to limitations of reproductive and growth potential. Prolonged dry periods will reduce available A and E in pasture forage, as can ensiling and prolonged storage of harvested feedstuffs. Polioencephalomalacia is a thiamin responsive disorder, associated with high concentrate feeding and lush pastures. Antimetabolites, such as amprolium, will cause thiamine deficiency when fed in excess. Recent information has shown improved performance with supplemental beta carotene and niacin. The positive responses in reproductive performance, noted with cattle fed supplemental beta carotene, was independent of vitamin A. Supplementation of vitamins above National Research Council recommendations can be justified. However, proper evaluation of feed and animal status, and documentation of a response to supplementation is necessary before diagnosing deficiencies of specific nutrients.  相似文献   

8.
Three experiments were undertaken to determine the efficacy of different doses of buparvaquone in the infection and treatment immunization of cattle against Theileria parva derived from African buffalo (Syncerus caffer). Two of these experiments also compared buparvaquone with standard doses of long- and short-acting formulations of oxytetracycline. In addition, different dilutions of stabilates were used in the experiments. In the first experiment, a 10(-1.0) dilution of stabilate was used to infect groups of cattle treated with buparvaquone at doses of between 5 and 0.625 mg kg-1 body weight (bwt) on Day 0 after infection. All control cattle developed severe theileriosis and none of the treatment regimes (including those utilizing long-acting oxytetracycline) prevented the development of theileriosis. Treatment with buparvaquone at 2.5 mg kg-1 bwt or oxytetracycline gave the most satisfactory results. In the second experiment when the sporozoite dose was reduced to 10(-2.0) dilution, buparvaquone treatment at 5 and 2.5 mg kg-1 bwt and short- and long-acting formulations of oxytetracycline reduced reactions greatly. While all the oxytetracycline treated animals produced a serological response and were immune to a 50-fold higher challenge with the immunizing stabilate, several animals in the buparvaquone groups did not show a serological response and were not immune to challenge. In the third experiment, groups of cattle were infected with 10(-1.2), 10(-1.4) and 10(-1.6) dilutions of stabilate and were treated with 2.5 mg kg-1 bwt of buparvaquone. No animals developed severe theileriosis and all seroconverted. On homologous challenge, however, two out of 14 cattle showed severe reactions. It was concluded that further work on immunization using buparvaquone treatment at 2.5 mg kg-1 bwt and 10(-1.6) dilution of the stabilate would have to be carried out before such a system could be used in the field.  相似文献   

9.
Evaluation trials of the efficacy of buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), as a treatment of field cases of Theileria parva infection (East Coast fever - ECF) were carried out on 63 cattle in the peri-urban of Dar Es Salaam city, Tanzania, during the period November 2004 to August 2005. Thirty-two cattle (56%) received single-dose treatment (2.5 mg buparvaquone per kg body weight), while two and three-dose treatment with interval(s) of 48 h was given to 33% and 11% of total treated cattle, respectively; 38 cattle (60.3%) were treated at an early stage of the disease, while 25 cattle (39.7%) were treated at an advanced stage of the disease. The rectal body temperature of 90.5% of buparvaquone-treated cattle dropped to normal values (37.5-39.5 degrees C) by day 7 of treatment, and by day 15 of treatment 96.8% of treated cattle showed normal values. Pulmonary signs were observed in 8/68 (11.8%) of total ECF diagnosed cattle and were successfully treated, albeit with parvaquone plus frusemide (Fruvexon); were not included in final evaluation of the efficacy of BUTA-kel. The present evaluation trials record a recovery rate of 95.2%. Buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), therefore, records another efficacious and valuable alternative treatment against East Coast fever in Tanzania.  相似文献   

10.
A series of hydroxynaphthoquinones, all derivatives of the antitheilerial hydroxynaphthoquinone parvaquone (993C, Clexon; Wellcome) was tested for antitheilerial activity against Theileria parva (Muguga) in vitro. BW720C (buparvaquone) was 20 times more active than parvaquone. When tested in vivo BW720C cured all 13 cattle infected with T parva and all six infected with T annulata treated at a dose rate of 2.5 mg (kg bodyweight)-1 while parvaquone at 20 mg kg-1 cured nine of 10 cattle. All 16 untreated control cattle died of theileriosis.  相似文献   

11.
The effect of beta carotene on disease protection and humoral immunity in chickens was investigated in comparison with the effect of other lipid-soluble antioxidant vitamins, vitamin E and A, which are both proven immunoenhancers and contributors to disease protection. Beta carotene alone was not as effective as either vitamin in protecting chickens from Escherichia coli infection, nor did it significantly enhance humoral immunity. In combination with vitamin E, however, beta carotene significantly increased disease protection and reduced hepatomegaly caused by E. coli infection.  相似文献   

12.
Plasma concentrations of vitamins A and E were examined in sheep, and a transitory decrease was observed after a single massive dose of vitamin D3 (5 X 10(6) IU) was administered orally or parenterally. Administration of a large dose of vitamin E to sheep decreased plasma retinol concentrations within 72 hours, but thereafter, the plasma retinol concentrations returned to near baseline values. Oral administration of a single pharmacologic dose of dl-alpha-tocopherol (5 g) to sheep caused a slow increase of this vitamin in the blood plasma. In cattle, a single IM administration of 3 liposoluble vitamins (A, D3, and E) at acceptable concentrations had no detectable influence on plasma alpha-tocopherol concentrations with the sampling intervals used. Plasma concentrations of alpha-tocopherol in these cattle showed a marked seasonal pattern; the concentrations increased from January to a peak in July, with a subsequent decrease in the fall. Also reported are estimates of inter- and intraindividual variation in plasma liposoluble vitamin concentrations.  相似文献   

13.
Seasonal variations in beta carotene intake and low levels of beta carotene and vitamin A in blood plasma were found in cows fed ration based mainly on maize silage. The supplementation of daily winter rations with 300 mg Rovimix-beta carotene per cow, beginning 14 days before parturition and 60 days after calving increased slighty the beta carotene and vitamin A concentrations of blood plasma and improved some fertility indices: the number of inseminations per cow was reduced and the percentage of conception rate was significantly higher. It may be assumed that beta carotene content in feeds and it's utilization rate generally reflected in beta carotene blood plasma level and in the improvement of fertility.  相似文献   

14.
托克逊县是牛环形泰勒虫病的疫区之一,准确诊断以及有效治疗是防控该病的要点。论文采用流行病学调查、实验室方法检测和临床诊断的方法综合确诊45头舍饲患牛作为研究对象。将45头阳性牛随机分为西药治疗组、中药治疗组以及空白组,按1、2、3、4、5d以及1周,分别对每组患牛进行临床症状观察、体温测定、血涂片观察、染虫率统计,评价治疗效果。结果表明,托克逊县夏乡5个镇散养户的194头牛血液涂片中62份有环形泰勒虫虫体;PCR检测有57份DNA样品得到与预期结果相同的534bp条带;临床诊断有45头牛表现为牛环形泰勒虫病症状;西药治疗组治愈率为93.33%(14/15)明显高于中药治疗组治愈率为73.33%(11/15)。西药组对于治疗环形泰勒虫病具有显著的效果,可为新疆有效治疗环形泰勒虫病提供参考。  相似文献   

15.
In the studies previously reported, the tick-borne protozoan parasites Theileria lestoquardi and Theileria annulata were shown to differ in their capacity to infect sheep and cattle. In the studies presented here, these findings were further supported. In vitro infectivity of T. lestoquardi and T. annulata sporozoites for peripheral blood mononuclear cells of sheep and cattle were determined by analysis of cell cultures for cell proliferation, the detection of parasites in Giemsa-stained cytospin smears and the establishment of continuously growing schizont-infected cell lines. In the same way, the development of schizont-infected cells into continuously growing cell lines was studied with material isolated ex vivo from the sheep and cattle undergoing primary infections described elsewhere. Comparisons were also made between development of ex vivo cell lines from animals undergoing primary infections with those of the animals undergoing challenge infection with the other parasite species. Theileria species specific primers were used in a PCR to determine the identity of the parasites in the cell lines. These in vitro studies confirmed earlier observations that T. lestoquardi was unable to infect cattle, whereas infection of all sheep with T. annulata was proven. Moreover, earlier indications of the development of partial cross-immunity in sheep of T. annulata to T. lestoquardi and vice versa were strengthened. These findings may thus have consequences for the understanding of the epidemiology of T. lestoquardi infections of sheep. On the other hand. since piroplasms were not demonstrated in sheep infected with T. annulata, such sheep will not be infective to ticks and will consequently be unlikely to play a role in the maintenance and transmission of T. annulata to cattle.  相似文献   

16.
In a trial conducted in the south of England in January to February 1989, blood samples were obtained from nine dairy herds with more than 30 cases of clinical mastitis/100 cows and from nine herds with less than 30 cases/100 cows during the previous 12 months. Whole blood glutathione peroxidase (GSHPx) activity and plasma vitamin E concentration were determined for 12 cows in each herd. The mean (+/-sd) values for the herds with the lower incidence of mastitis were 7.57 +/- 1.86 micrograms/ml plasma vitamin E and 23.8 +/- 22.8 U/ml rbc GSHPx activity, compared with 7.74 +/- 1.69 micrograms/ml plasma vitamin E and 20.61 +/- 8.8 U/ml rbc GSHPx activity for the herds with the higher incidence of the disease. These values indicate that the vitamin E levels were generally adequate but that some animals and herds had low GSHPx activities, suggesting that their diets may have contained inadequate selenium. The activities of GSHPx and the vitamin E levels in plasma were not significantly different in the two groups of herds, and no relationship was found between the two nutrients and the incidence of clinical mastitis. However, there was a significant negative correlation between the activity of GSHPx and the bulk milk cell counts in the herds with a low incidence of mastitis suggesting that there was an association between the incidence of subclinical mastitis or inflammation and the selenium status of these herds.  相似文献   

17.
Thirty buffaloes naturally infected with Theileria annulata and 10 parasitologically free controls were used to determine the potential clinical, haematological and therapeutic impact of tropical theileriosis in Egypt. The clinical signs in the infected buffaloes were pyrexia (40.5-41.5 degrees C), enlargement of superficial lymph nodes, slight nasal and ocular discharges, salivation, anaemia and respiratory distress. Eye lesions also were recorded. There was a significant decrease in erythrocyte counts and haemoglobin content and a significant decrease in total leucocyte counts in infected buffaloes compared to controls. Early treatment with buparvaquone was 100% effective in eliminating the protozoan parasites from the blood and lymph nodes and led to an improvement in the clinical state whereas treatment in the later stages of the disease whilst eliminating the parasites failed to improve the clinical condition of the animal.  相似文献   

18.
An enzyme linked immunosorbent assay (ELISA) was used to determine antibody levels in cattle infected with Theileria parva and T annulata, using antigens prepared from the intra-erythrocytic piroplasm stage of the parasites. Antibody levels in calves infected with T parva increased from the 16th day after infection to reach peak values at days 28 to 35 and then declined rapidly, but in calves infected with T annulata antibody levels rose steadily up to day 40. Similar patterns of antibody production were shown by indirect fluorescent antibody tests. Sera from animals infected with T parva gave higher ELISA values with the antigen prepared from the homologous parasite species than with the antigen prepared from T annulata, but sera from cattle infected with T annulata gave similar high ELISA values with antigens prepared from both T parva and T annulata. Sera from animals infected with T mutans, T sergenti, T velifera, Babesia divergens, B major and B bovis gave only slight or no cross reactions with the piroplasm antigens, but serum from a calf infected with B bigemina cross reacted at a significant level with both piroplasm antigens.  相似文献   

19.
This study was carried out to examine the relationship between the corpus luteum (CL) weight, CL and follicle diameters and progesterone, β‐carotene and vitamin A levels in reproductive organs of cattle obtained from the slaughterhouse. The β‐carotene and vitamin A levels were determined in plasma, CL and follicular fluid (FF) using a spectrophotometric method at different stages of the oestrous cycle (n=40) and at 3–6 months of pregnancy (n=10). The diameters of the CL and follicle were measured using ultrasonography. Plasma progesterone concentrations were determined by an enzyme immunoassay method. The vitamin A levels of the plasma, CL and FF were not related to each other. The highest plasma vitamin A levels were observed in the proestrus and oestrus, at which periods follicular activity dominates. The vitamin A levels in the CL and FF were negatively related to the weight and diameter of the CL and the diameter of follicle, respectively. In contrast to vitamin A, β‐carotene concentrations of plasma, CL and FF were significantly correlated with each other. The highest β‐carotene levels in the plasma, CL and FF were found during pregnancy when there is maximal luteal function, and the β‐carotene level of the CL was significantly correlated with the weight and diameter of CL. Furthermore, the intrafollicular β‐carotene level was negatively correlated with the follicle diameter. There was a positive correlation between plasma progesterone level and the weight and diameter of the CL, but a negative correlation between plasma progesterone level and follicle diameter. Moreover, plasma, FF and CL β‐carotene levels were positively correlated with plasma progesterone levels. This study revealed that β‐carotene levels in the plasma, CL and FF were influenced by the stage of the oestrous cycle or the pregnancy and were related to bovine luteal function without depending on vitamin A.  相似文献   

20.
OBJECTIVE: To examine the effects of injectable vitamins A, D and E at feedlot entry on health and growth rate and the effects of injectable vitamin C at the time of treatment for bovine respiratory disease (BRD) on cattle health. DESIGN: Systematic allocation of 2465 cattle at feedlot entry to: a commercial vitamin A, D and E preparation at the label dose rate; commercial vitamin A, D and E at twice the label dose rate; a formulation with no vitamin D, a lower concentration of vitamin A and a higher concentration of vitamin E; and the oil-based carrier alone at volumes corresponding to the above treatments. Comparisons of growth rate, disease and mortality were made between the groups at the conclusion of the feeding period. In a separate experiment, 176 cattle were alternately administered injectable vitamin C at the time of treatment for BRD, or were not injected with vitamin C, and mortality was compared between the groups. RESULTS: There were no differences between cattle administered vitamin A, D and E at feedlot entry and the controls in growth rate (P=0.11), all diseases (P=0.99), BRD (P=0.60) or mortalities (P=0.95). Cattle treated with the higher vitamin E and lower vitamin A preparation had a higher (P=0.02) incidence of anorexia than the other groups. Fewer cattle treated with 5 g of vitamin C by intramuscular injection at the time of treatment with antibiotics for BRD subsequently died (P=0.04). CONCLUSIONS: The routine injection of cattle with vitamins A, D and E at feedlot entry is unlikely to result in improvements in health and growth rate where cattle are provided with these vitamins in their diets at concentrations equal to the National Research Council recommendations. Mortality rate in cattle diagnosed with BRD may be reduced by intramuscular injection of vitamin C at the time of treatment with antibiotics.  相似文献   

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