PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “INFECTIOUS ABORTION”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources

Infectious bovine rhinotracheitis: a review and update.

Infectious bovine rhinotracheitis (IBR), a herpesvirus infection of cattle, has diverse clinical manifestations. Known mainly as a respiratory tract disease characterized by tracheitis, rhinitis, and fever, IBR plays a prominent role among causes of undifferentiated bovine respiratory disease and abortion. It also causes conjunctivitis, infectious pustular vulvovaginitis, balanoposthitis, and rarely, encephalitis. The virus is readily transmitted and has worldwide distribution. Some cattle develop a latent infection, which can be reactivated. The disease can be diagnosed by clinical signs and lesions and by a variety of virologic and immunologic techniques. Control of IBR is based largely on vaccination. A review is timely because efficient utilization of the wide assortment of available vaccines requires knowledge of recent developments in the diagnosis, immunology, and epidemiology of the disease.

Abortion, Veterinary↗

Studies on persistent infections of tissue culture. VI. Reversible changes in Newcastle disease virus populations as a result of passage in L cells or chick embryos.

Populations of the Victoria strain of Newcastle disease virus (NDV), reisolated from persistently infected L-cell cultures and passed twice in the embryonated hen's egg (NDV(L-E-2)), were found to differ strikingly from the original, chick embryo-adapted virus (NDV(o)). After exposure of L cells to NDV(o) at high multiplicities of infection, all cells became abortively infected; they produced only small aggregates of viral antigen and few, if any, infectious virus particles, but they yielded large amounts of interferon. No cytopathic effects (CPE) were noted, and the cultures survived readily as viral carriers. In contrast, NDV(L-E-2) yielded under similar conditions large quantities of viral antigen and infectious virus particles, but no detectable interferon, and the cultures were rapidly destroyed. This change in "virulence" was at least partially reversible by further serial passages of NDV(L-E-2) in chick embryos, as was evident from a consecutive decrease in CPE with a concomitant increasingly rapid recovery of the L-cell cultures, gradually diminishing yields of infectious viral progeny, and the returning of a capacity to induce interferon synthesis. Thus, NDV(L-E-16) resembled NDV(o) in many aspects, except for a less striking reduction in its ability to replicate in L cells. Although a selection of viral variants under the given sets of conditions has not been entirely excluded, the establishment of "avirulence" appears to be largely explained by a gradual accumulation of noninfectious, interferon-inducing components in the course of serial passages in the embryonated hen's egg, and the acquisition of "virulence" by a loss of these components. The evidence is as follows. (i) By a step-wise decrease in the dose of virus and restriction of the analyses to the first infectious cycle, a multiplicity of infection was ultimately reached for all "avirulent" populations at which infected cells produced normal yields of infectious viral progeny; i.e., the interferon-inducing components were diluted to noneffective levels. The lowest multiplicity which resulted in a measurable reduction in infectious virus replication was also the last one to induce detectable interferon synthesis. (ii) All viral clones derived from "avirulent" populations behaved like NDV(L-E-2) rather than like the parent viral suspensions, except that some of them elicited small amounts of interferon in L cells. The interferon-inducing components were reduced or lost in the cloning procedures. The nature of the interferon-inducing components has not been established. These components, which were neutralized by rabbit sera against "virulent" NDV(L-E-2) populations, may represent largely inactive or incomplete virus particles; however, the infectious virus-hemagglutinin ratios of "avirulent" populations were mostly of an order similar to those of "virulent" populations. The interferon-inducing components aborted the infectious process in cells simultaneously invaded by infectious virus particles. The implications of these findings are discussed.

Animals↗

Kinetics of viral deoxyribonucleic acid, protein, and infectious particle production and alterations in host macromolecular syntheses in equine abortion (herpes) virus-infected cells.

Infection of exponential-phase suspension cultures of mouse fibroblast cells (L-M) with equine abortion virus (EAV) resulted in inhibition of cell growth and marked alterations in host metabolic processes. The synthesis of deoxyribonucleic acid (DNA) and ribonucleic acid was inhibited within 4 hr after infection and was suppressed by more than 90% by the time of maximal virus replication (14 to 18 hr). The overall rate of protein synthesis, however, was similar in uninfected and virus-producing cells as determined by measurements of net protein and isotope incorporation. The time course of viral DNA and protein synthesis and assembly into mature virus was determined with the inhibitors 5-fluorodeoxyuridine (FUdR) and cycloheximide, respectively. Thus, viral DNA synthesis was essentially completed at 14 hr, and viral protein and infectious virus synthesis was completed at 18 hr. Although the number of plaque-forming units (PFU) produced by FUdR-treated cells (10(3) to 10(4) PFU/ml) was at least 3 logs less than that produced by untreated cells, the yield of physical particles (as determined by electron microscopy) was approximately the same at 30 hr after infection. Besides being relatively non-infective, the particles produced in FUdR-treated cells appeared morphologically incomplete as they contained little or no nucleoid material.

Abortion, Veterinary↗

Growth characteristics of influenza virus concerning the binding of virus by host cells.

Under certain conditions, influenza virus may bind to chorioallantoic membrane and the infectious property is retained upon prolonged incubation of the complex. Apparently the bound active virus is not functioning in the initiation of viral increase. The bound infectious virus may be partially removed by extensive washing. The characteristics of the washing are suggestive of a reversible equilibrium type of binding. Binding will also occur when the tissue has been pretreated with RDE or in the presence of AMPS. However, under these conditions the binding is of a lesser degree. When the tissue has been treated with RDE and AMPS is present, no stable binding occurs. In the presence of AMPS, the initiating activity is bound but cannot function in promoting viral increase. It is proposed that active virus is held by two types of binding at the same site; one type of binding is sensitive to the action of RDE; the second type is sensitive to the blocking effect of AMPS. Virus can be held to the receptor site by either type of binding or both. It is further suggested that the bound infectious virus is a result of an abortive attempt at initiating infection. The nature of the binding of infectious virus is of significance for understanding the binding of initiating activity.

Binding Sites↗

Diagnostic survey of bovine abortion in Korea: with special emphasis on Neospora caninum.

Causes of bovine abortion were surveyed in Korea within a designated period from the cases submitted to the Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University. One hundred and eighty aborted fetuses and maternal sera were evaluated by necropsy, histopathology, bacteriology, virology, PCR, and serologic tests. The causes of abortion were identified in 108 (60%) cases, of which 38 (21.1%) were due to the infection with Neospora caninum. None of the 38 cases showed any co-infection with either virus or bacteria. Viral and bacterial causes were diagnosed in 28 (15.5%) and 13 (7.2%) aborted fetuses, respectively. Non-infectious causes such as multiple pregnancy, maternal weakness or torsion of umbilical cord were observed in 22 (12.3%) cases. Results of the present study suggest that N. caninum is believed to be the leading cause of bovine abortion in Korea. Thus, more attention should be paid to this emerging disease in Korea. However, the causes of many aborted fetuses remain undiagnosed in this study. Therefore, this enigma should be clarified through further studies such as chromosomal analysis.

Abortion, Veterinary↗

Causes of caprine abortion: diagnostic assessment of 211 cases (1991-1998).

In an 8-year period, 1991-1998, 217 accessions of caprine abortions were submitted to the California Veterinary Diagnostic Laboratory System. Of these 217 submissions, 211 were suitable for examination in this study (6 had insufficient data). Infectious agents as the cause of abortions were found in 37% of the cases: bacterial agents were identified in 30.5%, viral agents in 2%, fungal agents in 0.5%, and protozoal agents in 4% of the cases submitted. The most common causes of abortions were Chlamydia psittaci and Coxiella burnetii infection, which accounted for 23% of all goat abortions. Mineral deficiencies were observed in 4%, fetal anomalies accounted for 3%, and leukoencephalomalacia of the brain (probable oxygen deprivation) accounted for 3% of the submissions. No diagnosis was made in 112 of the 211 submissions (53%). No lesions were noted in 104 of the submissions (49%). The other 8 submissions (4%) had histologic lesions suggestive of a bacterial agent; however, no infectious agents were identified in these cases.

Abortion, Veterinary↗

Hospitalisation among immigrants in Italy.

BACKGROUND: Immigration is increasing in Italy. In 2003, 2.6 million foreign citizens lived in the country; 52% were men and the majority were young adults who migrated for work. The purpose of this study was to investigate differences in hospitalisation between immigrants and the resident population during the year 2000 in the Lazio region. METHODS: Hospital admissions of immigrants from Less Developed Countries were compared to those of residents. We measured differences in hospitalisation rates and proportions admitted. RESULTS: Adult immigrants have lower hospitalisation rates than residents (134.6 vs. 160.5 per thousand population for acute care; 26.4 vs. 38.3 for day care). However, hospitalisation rates for some specific causes (injuries, particularly for men, infectious diseases, deliveries and induced abortions, ill-defined conditions) were higher for immigrants than for residents. Immigrants under 18 years seem to be generally healthy; causes of admission in this group are similar to those of residents of the same age (respiratory diseases, injuries and poisoning). The only important differences are for infectious and parasitic diseases, with a higher proportion among immigrant youths. CONCLUSION: The low hospitalisation rates for foreigners may suggest that they are a population with good health status. However, critical areas, related to poor living and working conditions and to social vulnerability, have been identified. Under-utilisation of services and low day care rates may be partially due to administrative, linguistic, and cultural barriers. As the presence of foreigners becomes an established phenomenon, it is important to evaluate their epidemiological profile, develop instruments to monitor and fulfil their specific health needs and plan health services for a multi-ethnic population.

Journal Article↗

Post conception failures in reproduction: infectious diseases and immunitary problems.

The mechanism by which early abortions may be caused by infections disease or immunological problems are discussed by the Authors. Among the first group of causes, syphilitic infections, rubela, viral diseases and others are examined. Immunological problems which may lead to early abortions are then discussed in the more complex context of mother/embryo interactions, examined also on the basis of experimental models. All the hypotheses which may explain refusal of embryo are examined, but the Authors stress the fact that also in proven cases of immunological refusal of pregnancy, the question of the usefulness of immunological therapy remains unanswered.

Abortion, Spontaneous↗

[Application of intravenous immunoglobulin therapy (IVIG) in pregnant patients with recurrent spontaneous abortions].

OBJECTIVE: Clinical outcome of pregnancy in patients with recurrent pregnancy losses treated with IVIG during their current pregnancy. MATERIAL AND METHODS: The study group consisted of 10 pregnant women with 3-5 spontaneous abortions. Any genetic, anatomical or infectious abnormalities were excluded as well as antiphospholipid antibody syndrome and negative lymphocytotoxic test. The treatment consisted of passive immunotherapy by means of intravenous administration of immunoglobulin (IVIG) at a dose of 0.4 g/kg b.w. Therapy was commenced at week 5-6 of gestation, infusions were repeated every 3-4 weeks until 28th week of gestation in 5-, 3- and 1-day protocols. In 2 patients that therapy followed active immunotherapy with paternal lymphocytes. RESULTS: Eight (80%) patients bore healthy babies (3 preterm); in 2 cases embryos died at 6-7 week of gestation. CONCLUSIONS: The results confirm the efficacy of IVIG in pregnant patients with recurrent spontaneous abortions in whom likelihood of immunological pattern of pregnancy failures is high.

Abortion, Habitual↗

Prevalence of Chlamydia trachomatis in women seeking termination of pregnancy.

Fifty consecutive unmarried women seeking termination of pregnancy in Toa Payoh Hospital were analysed to determine the prevalence of Chlamydia trachomatis infection as compared to gonococcal infection. Cases harbouring chlamydial infection were followed up to exclude postabortal pelvic infection. Incidence of positive cultures were also compared among the various ethnic groups in the population. Results from the data analysed showed that chlamydial infection was significantly more prevalent than gonorrhoea in our local women seeking therapeutic abortion. However, further research to define the exact size of the problem is indicated.

Abortion Applicants↗

THE RUBELLA DILEMMA.

Explore the source record for details and available documents.

Abortion, Therapeutic↗