Inoculation of pregnant beef heifers at midgestation with Anaplasma marginale

Fifteen artificially inseminated beef heifers negative for Anaplasma marginale complement fixing (CF) antibody were used in this study. Twelve of fifteen heifers were inoculated in the second trimester of gestation with whole blood from an anaplasmosis carrier cow. Three inseminated heifers served as uninoculated controls. All inoculated heifers became anemic and developed positive anaplasmosis CF antibody titers. All heifers delivered full term viable calves with negative precolostral serum anaplasmosis CF antibody titers.

This experiment demonstrates that pregnant beef heifers in the second trimester of gestation do not abort as a result of anaplasmosis, and further that transplacental transmission of Anaplasma marginale may not occur at midgestation.     

Anestrus in cycling beef heifers experimentally inoculated with

Normal estrous cycles were established for twenty beef heifers. Ten heifers were inoculated with blood from a known carrier. The inoculated heifers experienced anemia, anorexia, and positive complement-fixing antibody titers, and . was observed on the erythrocytes while uninoculated control heifers remained normal. Further observation following inoculation revealed that five of ten inoculated heifers experienced anestrus while controls continued to cycle normally. Anestrus coincided with clinical signs of acute anaplasmosis. Normal estrus patterns returned following treatment and recovery. This study provides evidence that acute anaplasmosis in beef heifers may cause anestrus and therefore lead to reproductive inefficiency.     

Vertical transmission of Anaplasma marginale in cattle

Ten Hereford heifers in the third trimester of gestation and negative for Anaplasma marginale complement fixing (CF) antibody titers were used in this study. Six of the 10 heifers were inoculated with blood from a known anaplasma carrier animal. Four heifers served as uninoculated controls. Four fetuses from the principal heifers and 3 from control heifers were surgically recovered. All fetuses were alive at the time of surgical recovery. One inoculated heifer delivered a dead autolyzed fetus and one delivered a live healthy calf. One control heifer delivered a live healthy calf. Blood from 4 fetuses and 1 calf recovered from the inoculated heifers was subinoculated into splenectomized CF negative calves. Two of 5 subinoculated calves developed anaplasmosis. This study provides evidence of vertical (transplacental) transmission of Anaplasma marginale in pregnant heifers in the last trimester of gestation.     

Serological comparison of Australian and South American strains of Babesia argentina and Anaplasma marginale

The indirect fluorescent antibody test was used for the serological comparison of the parasites called Babesia argentina and Anaplasma marginale in Australia and Bolivia, South America. Cross-testing performed with antigens and antisera prepared in the two continents proved serological identity for both parasites. Because a similar study by Goldman & Rosenberg (1974) showed serological identity between B. bovis and B. argentina, by the law of priority the small Babesia of Australia and South America should be called B. bovis. The findings have implications in vaccination.     

Epidemiology and risk factors associated with Anaplasma marginale infection of cattle in Peninsular Malaysia

Bovine anaplasmosis is a major concern to cattle farming in most parts of the world. Anaplasmosis negatively impacts the profitability of cattle farming by reducing the production, reproduction, and draft ability of cattle. Here, we report results from a one-year cross sectional study to determine the epidemiology and the risk factors for Anaplasma marginale infection of cattle in Peninsular Malaysia. Examination of one thousand and forty five blood samples of apparently healthy cattle from forty-three farms in all the states of Peninsular Malaysia by polymerase chain reaction (PCR) assay revealed an overall prevalence of A. marginale infection of cattle of 72.6%, showing high endemicity of this heamoprotozoan among cattle in the country. Cattle breeds, production type, herd owner, herd size, management system, farm size, farm age, prophylactic treatment against blood parasites, presence of ticks, frequency of deticking, zones, closeness to forest, closeness to waste area, closeness to human settlement and closeness to body of water were the risk factors significantly associated (P?<?0.05) with the detection of A. marginale in cattle. Results of this first molecular study on the epidemiology and risk factors for A. marginale infection of cattle from all the states of Peninsular Malaysia suggest policies and strategies for the prevention and control of the parasite to improve profitability of cattle farming in the country.     

Abnormal bovine erythrocyte membrane proteins and glycoproteins during and after infection with Anaplasma marginale

The erythrocyte membrane proteins from normal and Anaplasma-infected bovine blood have been compared. Two distinct new polypeptides were present in membranes from acutely infected cells. The glycoprotein pattern was also altered: in addition to the three main bands observed in normal cells, there were four new bands present which were glycosylated. The normally found membrane glycolypeptide (250000 D) was missing. The role of these protein alterations in relation to the infectious process is discussed.     

Anestrus in cycling beef heifers experimentally inoculated with Anaplasmamarginale

Normal estrous cycles were established for twenty beef heifers. Ten heifers were inoculated with blood from a known $\text{Anaplasma}$$\text{marginale}$ carrier. The inoculated heifers experienced anemia, anorexia, and positive $\text{Anaplasma}$$\text{marginale}$ complement-fixing antibody titers, and $\text{A}$. $\text{marginale}$ was observed on the erythrocytes while uninoculated control heifers remained normal. Further observation following inoculation revealed that five of ten inoculated heifers experienced anestrus while controls continued to cycle normally. Anestrus coincided with clinical signs of acute anaplasmosis. Normal estrus patterns returned following treatment and recovery. This study provides evidence that acute anaplasmosis in beef heifers may cause anestrus and therefore lead to reproductive inefficiency.     

Testicular degeneration and libido loss in beef bulls experimentally inoculated with Anaplasma marginale

Four sexually mature virgin beef bulls were inoculated with whole blood from a known Anaplasma marginale carrier. All four bulls became infected and experienced some degree of anemia and testicular degeneration, while uninoculated controls remained normal. Testicular degeneration was confirmed by electron microscopy, histopathology, and semen evaluation. Further observations established that the inoculated bulls exhibited a loss of libido, while controls reacted in a normal manner to a cow in estrus. Anaplasma marginale was not present in semen of inoculated bulls.     

Anemia associated with anestrus in beef heifers inoculated with Anaplasmamarginale: Endocrinology and ovarian changes

Eleven cyclic Hereford heifers were synchronized to estrus with a commercial luteolytic agent. Eight heifers had been inoculated with $\text{Anaplasma}$$\text{marginale}$. Six of the eight inoculated heifers became anemic, i.e. packed cell volume, red blood cell counts and hemoglobin decreased. White blood cell counts were elevated during severe anemia. Anemic heifers did not show behavioral estrus or ovulate, and during this stage, serum concentrations of progesterone and estradiol-17β were significantly depressed. Mature beef heifers that have acute anaplasmosis suffer from inhibited ovarian function and anestrus.     

Babesia bigemina,Babesia argentina, and Anaplasma marginale: Coinfectious immunity in bovines

Forty-eight intact and eight splenectomized cattle were used to evaluate different systems of coinfectious immunization against Babesia bigemina, Babesia argentina, and Anaplasma marginale. Coinfectious immunity was induced by two methods: (1) blood of cattle acutely infected with B. bigemina, B. argentina and A. marginale was used as the source of inoculum and the post vaccination reactions were chemotherapeutically controlled with Imidocarb, Ganaseg, Gloxazone, and Liquamycin, and (2) by artificially inducing babesiosis with the blood of carrier cattle with chronic infections of B. bigemina and B. argentina without chemotherapy. The degree of resistance was determined by bloodborne and tick-borne challenges. Ticks were collected from cattle and identified as Boophilus microplus and Dermacentor nitens. Vaccinated cattle demonstrated a high degree of resistance to babesiosis and anaplasmosis; however, cattle without coinfectious immunity were treated chemotherapeutically to prevent death losses.     

Bovine lentivirus induces early transient B-cell proliferation in experimentally inoculated cattle and appears to be pantropic.

Bovine immunodeficiency-like virus (BIV) was first isolated in 1972 (M. J. VanDerMaaten et al., J. Natl. Cancer Inst. 49:1649-1657, 1972). Much work has been done on the molecular characterization of BIV in studies using the original BIV R29 isolate; however, R29 is believed to be attenuated since it no longer causes either mononuclear cell number increases or detectable enlargement of lymphatic nodules in experimentally infected cattle. The host cell tropism and changes in host peripheral blood lymphocyte populations following infection with BIV are unknown. Recently, we isolated and characterized a field isolate of BIV, FL112 (D. L. Suarez et al., J. Virol. 67:5051-5055, 1993) that causes a transient, mononuclear cell lymphocytosis in experimentally infected cattle. In the present study, cattle were inoculated with BIV FL112, and data from flow cytometry showed that BIV causes a B-cell lymphocytosis with no consistent, significant changes in other mononuclear cell populations, including CD3+, CD4+, and CD8+ cells. Cell sorting and PCR amplification were used to show that BIV may be pantropic. Proviral DNA was present in CD3+, CD4+, CD8+, and B-cells, monocytes, and WC1 cells (gamma/delta T cells, null cells) by 3 to 6 days postinoculation and also at 2.5 years postinoculation.     

Ovarian function in crossbred beef heifers treated with dexamethasone

Each of 32 crossbred beef heifers was brought from pasture on day 16 of its estrous cycle and assigned randomly to one of four treatment groups as follows: Field Control (FC), Field Dexamethasone (FD), Pen Control (PC), and Pen Dexamethasone (PD). Field groups were kept in a 0.8-ha field and pen groups were kept in 4.6-x 9.8-m pens in a pole barn during the trial. Dexamethasone (DEX) groups received 20 mg of DEX on cycle day 16 and 30 mg daily on days 17 through 20. Control heifers received an equal volume of physiological saline solution on corresponding cycle days. Average treatment cycle lengths (±SD) for control heifers in FC and PC groups were 21.1 ± 2.8 and 21.6 ± 1.8 days, respectively, and were not significantly different. Average time from progesterone decline (<1 ng/ml) to estrus was two days for each of the control groups. Four DEX-injected heifers had not shown estrus by day 44 of the treatment cycle. Progesterone had declined for two of these heifers by cycle day 18 and remained below 1 ng/ml past cycle day 48. The other two showed a decline in plasma progesterone by cycle days 18 and 32, respectively, and a progesterone rise by day 42 without having been detected in estrus. The remaining 12 DEX heifers had an average cycle length of 29.4 days. Four extended cycles resulted from extended CL function, five from an extended period from progesterone decline to estrus and three from a combination of these factors. These observations suggest that the administration of pharmacological doses of glucocorticoid during the late diestrus or early proestrus may result in altered ovarian function.     

Pathological studies on encephalitis in mice experimentally inoculated with bovine coronavirus

One- to 21-day-old mice were examined pathologically after inoculated intracerebrally or subcutaneously with the Kakegawa strain of bovine coronavirus. In 1- to 4-day-old mice inoculated intracerebrally, the brain contained a small number of neutrophils and lymphocytes having infiltrated diffusely and perivascularly and some degenerative neurons. In mice inoculated intracerebrally at 7 to 21 days of age, severe necrosis of pyramidal cells was shown in Ammon's horn. Perivascular infiltrations of neutrophils and lymphocytes were moderate to severe. Some neurons were degenerative in the cerebral cortex, thalamus and midbrain. Degeneration of some neurons and mild infiltration of neutrophils and lymphocytes were observed in the brain of mice inoculated subcutaneously at 1 to 7 days of age. Perivascular infiltration of neutrophils and lymphocytes was prominent in the cerebral cortex of mice inoculated subcutaneously at 14 days of age. Cellular infiltration was also seen in the thalamus, Ammon's horn, midbrain, cerebellum and medulla oblongata. All the mice, except one, inoculated subcutaneously at 21 days of age were free from neural changes. Electron-microscopically, virus particles were observed in and outside of the degenerative neurons. They had a core 70 nm in diameter and an envelope with spikes.     

Sesquiterpenoid stress compounds from Nicotiana rustica inoculated with TMV

Sesquiterpenoid stress compounds, occidol, occidol isomer-1 occidol isomer-2, occidol acetate and phytuberin have been isolated from the leaves of Nicotiana rustica inoculated with TMV. Isomers 1 and 2 and the acetate are sesquiterpenoids not previously reported in nature.     

Synchronization of estrus after treatment with Luprostiol in beef cows and in beef and dairy heifers

Four trials were conducted to study synchronous estrous response in beef cows and in beef and dairy heifers to Luprostiol (13, thia-PG-F(2)alpha analog) in comparison with other prostaglandin products. In Trial 1, 60 virgin beef heifers were observed for estrus for 5 d and artificially inseminated. Heifers not observed in estrus within 5 d were randomly assigned to receive 15 mg Luprostiol or 25 mg Lutalyse. In Trial 2, 75 multiparous, lactating beef cows were randomly assigned to receive either 15 mg Luprostiol, 25 mg Lutalyse or 500 mcg Estrumate. All cows received a second injection of the respective treatment 11 d later. In Trial 3, 96 multiparous, lactating beef cows were randomly assigned to receive 15 mg Luprostiol or 25 mg Lutalyse. All cows received a second injection of the respective treatment 11 d later. In Trial 4, virgin dairy heifers were palpated per rectum. Seventy-seven heifers with a palpable corpus luteum (CL) were randomly assigned to receive 15 mg Luprostiol or 500 mcg Estrumate. In all trials animals were artificially inseminated 12 h following observed estrus. Estrous response during the 5-d synchronized period was 44% for Luprostiol and 42% for Lutalyse treated heifers in Trial 1. It was 52, 56 and 60%, respectively, for Luprostiol, Lutalyse and Estrumate treated cows in Trial 2; 23% for Luprostiol and 19% for Lutalyse treated cows in Trial 3; and 68% for Luprostiol and 70% for Estrumate treated heifers in Trial 4. Treatment with Luprostiol results in a similar synchronous estrous response as with the other prostaglandin products used in these studies.     

Comparison between micro-hematocrit centrifugation technique and polymerase chain reaction (PCR) to detect Trypanosoma evansi in experimentally inoculated goats

Natural Trypanosoma evansi infection in the Canary Islands has only been diagnosed in the camel population, but dissemination of the disease in other hosts has not been excluded. To evaluate the role of the goats in the dissemination of the disease, 8 goats were inoculated and examined during 6 months using a polymerase chain reaction (PCR) with a primer targeting a repetitive region specific for Trypanozoon subgenus used to amplify a 227 bp fragment from the genomic DNA. PCR was able to detect parasitemia in all tested samples; therefore it was considered as gold standard test in this study. The results were compared with those obtained using the micro-hematocrit centrifugation technique showing a sensitivity of 92.7%, specificity of 100%, positive predictive value of 1 and negative predictive value of 0.87. Both techniques seem to be adequate to detect T. evansi from infected goats.     

Accumulation of phytuberin and phytuberol in tobacco callus inoculated with Pseudomonas solanacearum or Pseudomonas syringae pv. Tabaci

Tobacco callus tissues inoculated with Pseudomonas solanacearum or Pseudomonas syringae pv. tabaci accumulated phytuberin and phytuberol. Accumulation of the two sesquiterpenoids was dependent upon: the source (cultivar) of the explant; the number of transfers; the period which had elapsed after transfer; the bacterial species, and the time after inoculation.     

Synchronization of estrus in cyclic beef heifers with the prostaglandin analog alfaprostol

Seventy-eight Hereford-Angus crossbred heifers were injected intramuscularly twice with 6 mg of alfaprostol^b in 6 ml of propylene glycol. On each representative day of a 20-day estrous cycle (estrus = Day 0), either three or four heifers received their first injection. The second injection was given 12 days after the first, regardless of the response to the first injection. Thirty-nine heifers were not treated. The first alfaprostol injection reduced serum progesterone to less than 1 ng/ml in all heifers injected after Day 4. A total of 79.5% ($\text{62}\text{78}$) of the heifers exhibited estrus by five days after the first injection. Average interval from injection to estrus was 63 hours. The second injection occurred on Days 6 through 16 for all but one heifer, with 75.6% ($\text{59}\text{78}$) falling on Days 8 through 11 of the estrous cycle. Estrus was detected in 93.6% ($\text{73}\text{78}$) of the heifers within five days after the second injection, with an average interval to estrus of 66 hours.Day of cycle at second injection did not affect the interval to estrus. Conception occurred in 79.4% ($\text{58}\text{73}$) of the heifers inseminated in the five days after the second injection. Occurrence of estrus and conception was no different in treated heifers after five days of the insemination period than in nontreated heifers after 21 days of the insemination period, where 94.9% ($\text{37}\text{39}$) were observed in estrus and 83.8% ($\text{31}\text{37}$) conceived. Overall percent conception for a 55-day insemination period was 89.7 ($\text{70}\text{78}$) for treated and 87.2 ($\text{34}\text{39}$) for nontreated heifers. Day of cycle at first or second injection did not affect conception after the second injection. Some signs of estrus were observed in 11 of the 16 heifers injected before Day 5.A second trial to determine if alfaprostol induced luteolysis early in the cycle was conducted. Twenty purebred Angus, Hereford, or Simmental heifers received either one or two injections of alfaprostol on either Day 1, 2, 3, or 4. Only five heifers showed any signs of estrus, and the three that were inseminated did not conceive. Subsequent cycle length indicated that luteolysis occurred in only one heifer.Data suggest that alfaprostol is an effective luteolytic agent in cyclic beef heifers after Day 4 and that two injections 12 days apart will effectively synchronize estrus in heifers when distributed throughout the cycle at the first injection without affecting conception rate.     

Contrasting effects of anoxia on rhizome lipids in Iris species

A 14-day period of anoxia resulted in losses of polar lipids, particularly their saturated fatty acid components, from the anoxia-tolerant species Iris pseudacorus. By complete contrast, the anoxia-intolerant, closely related species I. germanica, although possessing a highly similar lipid profile, exhibited no changes in lipid composition in response to anoxia. The consequences of the lipid alterations in I. pseudacorus for membrane function and their possible role in adaptation to anoxia are discussed.