Mice infected with LP-BM5 murine leukemia viruses develop a syndrome, termed mouse AIDS (MAIDS), characterized by increasingly severe immunodeficiency and progressive lymphoproliferation. Virus-infected mice were examined for the ability to resist acute infection and to control chronic infection with the protozoan Toxoplasma gondii, a major opportunistic pathogen of individuals infected with human immunodeficiency virus. Mice infected with the retroviruses for 2 or 4 weeks responded normally to challenge with the parasite, but mice inoculated with the protozoan 8 or 12 weeks after viral infection died with acute disease due to T. gondii. Increased sensitivity to acute infection was associated with a reduced ability to produce gamma interferon (IFN-y) and with established changes in CD4+ T-cell function. Mice latently infected with T. gondii and then inoculated with the retrovirus mixture were found to reactivate the parasite infection, with 30 to 40% of dually infected animals dying between 5 and 16 weeks after viral infection. Reactivation was associated with
Respiratory tract infections are often treated empirically without investigation to detect the aetiological agent, which may be a virus or a bacterium, including atypical pathogens such as Chlamydophila pneumoniae or Mycoplasma pneumoniae. Recently, several types Chlamydia-like intracellular bacteria have been detected in environmental samples and clinical specimens. Little is known of their geographical distribution and potential pathogenicity. We describe the detection, by PCR and isolation in cell culture, of Simkania negevensis in nasopharyngeal aspirates of paediatric patients with bronchiolitis in Cornwall, UK. We also present serological evidence of exposure to the organism in 62% of adult patients and 46% of a sample of pregnant women. Empirical treatment of serious respiratory tract infection should consider the possible contribution of these organisms.
. 9. BALB/c female mice received bilateral, stereotaxic implantations of indwelling 25-gauge stainless steel guide cannulae under Avertin anesthesia at least a week before drug infusion. To avoid damage to the AOB and to vomeronasal nerves, these cannulae were implanted immediately anterior to the AOB.
10.11.Estrous females received one or two 0.5-gi infusions of a drug at 0 and 1.5 hours during a 6-hour exposure to bedding soiled by a BALB/c male or to bedding with no pheromone. At the next estrus, these females were mated either with a male of a CBA strain or with a BALB/c male. The females were left with the stud males for 6 hours after mating and were then removed to a clean cage for the rest of the experiment. Between 24 and 26 hours after mating, the females were exposed to the pheromones of a BALB/c male or of a CBA male for 48 hours to test for pregnancy block. Six days after mating, the females were killed by cervical dislocation and their uteri were examined for implantation sites. In these experiments, no seizures were caused by infusions of either tACPD or DCG-IV. In addition, the seizures that are frequently caused by infusions of ionotropic receptor antagonists (12) were also completely prevented by combined infusions with DCG-IV.
Over the period of a year, colitis was observed in 44 mice raised in a conventional nonspecific pathogen–free colony, 41 of these having concomitant retrovirus–induced murine acquired immunodeficiency syndrome (MAIDS). The lesions varied from bacterial colonization to hyperplasia of colonic mucosa to severe, often fatal, ulceration. Citrobacter rodentium was isolated from the colon and/or liver of 2 mice with colitis. When C57BL/6 mice with or without MAIDS were given graded doses of the bacterium, only those with MAIDS developed colitis, and C rodentium was reisolated from their livers. Thus, mice with MAIDS can develop severe disease following opportunistic infection with an environmental contaminant of the colony that is nonpathogenic for normal adult mice.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.