Avian influenza adenovirus-vectored in ovo vaccination: target embryo tissues and combination with Marek's disease vaccine.

We investigated embryo tissues targeted by replication competent adenovirus (Ad)-free recombinant Ad expressing a codon-optimized avian influenza (AI) H5 gene from A/turkey/WI/68 (AdH5) when injected into 18-day embryonated eggs. We also evaluated the effects of concurrent in ovo vaccination with the experimental AdH5 vaccine and commercially available Marek's disease virus (MDV) vaccine combinations Rispens/turkey herpesvirus (HVT) or HVT/SB-1. Computed tomography indicates that in ovo injection on day 18 of incubation places the solution in the amnion cavity, allantoic cavity, or both. Ad DNA was consistently detected in the chorioallantoic membranes as well as in the embryonic bursa of Fabricius, esophagus, and thymus 3 days postinoculation. H5 expression in these tissues also was detected by immunofluorescence assay. These results indicate possible swallowing of vaccine virus contained in the amnion. In contrast, vaccine localization in the allantoic fluid would have allowed bursal exposure through the cloaca. When the AdH5 vaccine was used in combination with MDV, chickens responding to the AdH5 vaccine had similar AI antibody levels compared with AdH5-only-vaccinated birds. However, combined vaccinated groups showed reduced vaccine coverage to AI, suggesting some level of interference. The combination of AdH5 with MDV Rispens/HVT affected the vaccine coverage to AI more severely. This result suggests that the replication rate of the more aggressive Rispens strain of serotype 1 may have interfered with the Ad-vectored vaccine. Increasing the Ad concentration produced similar AI antibody titers and AI vaccine coverage when applied alone or in combination with the HVT/SB-1 vaccine. Ad DNA was detected in hatched chickens 2 days after hatch but was undetectable on day 9 after hatch. MDV DNA was detected in feather follicles of all vaccinated birds at 12 days of age. Thus, Ad-vector vaccination does not interfere with the efficacy of MDV vaccination by using any of the commonly used vaccine strains.

Disseminated toxoplasmosis in a captive ring-tailed lemur (Lemur catta).

A 3-yr-old secundiparous female ring-tailed lemur presented to the Auburn University Small Animal Clinic with signs of dyspnea, lethargy, and anorexia. The animal died before she could be examined, and a full necropsy was immediately performed. Provisional necropsy findings included moderate pneumonia and hepatopathy. Acute interstitial pneumonia and focal hepatocellular necrosis were confirmed histologically. Lung impression smears, histopathology, electron microscopy, immunohistochemistry, and tissue culture isolation resulted in a diagnosis of acute disseminated Toxoplasma gondii infection, which was confirmed by polymerase chain reaction. The isolate of T. gondii was avirulent for mice and was named AU Tgl and genetically is type II. The source of the infection remains unclear, but speculation suggests contaminated fruit or blackbirds (Passeriformes: Icteridae) acting as transport hosts for oocysts from nondomestic felids and feral cats on the property.

In vivo protection of normal mouse hematopoiesis by a beta 2 blocking agent during S-phase chemotherapy.

Butoxamine, a beta 2-adrenergic blocking agent, which temporarily blocks the G1-S transition of human bone marrow granulocyte precursors in vitro, was used in vivo together with 1-beta-D-arabinofuranosylcytosine (ara-C) in mice. Butoxamine alone depressed the granulocyte labeling index and granulocyte-monocyte colony-forming Cell (GM-CFC) suicide rate at a dose of 3 micrograms/g body weight. A maximum effect was produced 6 to 12 hr after injection. Butoxamine administered 8 hr before an injection of ara-C modified the proportion of GM-CFC in S phase as compared with the number found after ara-C alone. After a series of five ara-C injections, administered at intervals of 16 hr, 70% of the treated mice died within 2 weeks, whereas only 42% of mice pretreated with butoxamine 7 to 9 hr before each ara-C injection died. This difference was due to the more rapid return to normal of GM-CFC numbers and an increase in the proportion of GM-CFC and granulocyte precursors in S phase in the butoxamine-pretreated animals. These findings suggest that butoxamine may have a potential use in protecting hematopoiesis during intensive chemotherapy for cancer.

Effect of beta adrenergic agonists and beta blocking agents on hemopoiesis in human bone marrow.

The effect of propranolol (non specific blocking agent), acebutolol (beta 1 blocking agent), butoxamine (beta 2 blocking agent) and several beta adrenergic agonists was studied on 3H-thymidine (3H-TdR) incorporation and granulo-monocyte colony formation in agar by human bone marrow. Only butoxamine and propranolol decreased 3H-TdR incorporation by total normal bone marrow cells at concentrations above 10(-6) M for butoxamine and 10(-5) M for propranolol. Autoradiography showed that inhibition of 3H-TdR incorporation by butoxamine was slightly more pronounced on neutrophil precursors than on red cell precursors (neutrophil series LI..53 and erythroblasts .67 compared to control bone marrow cells at 10(-5) M concentration). The development of granulo-monocyte colonies in agar culture was delayed by preincubation with butoxamine at concentrations above 5 X 10(-6) M. Hydroxyurea suicide showed that this was due to a decrease in the number of CFU-C in S phase. beta 2 blocking agents are able to decrease the number of normal hematopoietic cells entering S phase. This effect is seen on both neutrophil and erythroblastic precursors and on granulo-monocyte progenitors. It could be used as a means of protecting bone marrow cells during cancer intensive chemotherapy.

Effect of different sedative drugs on the proliferation of bone marrow cells. Preliminary results.

Several drugs were assayed for their effect on bone marrow hematopoïetic cells proliferation. Chlorpromazine, barbiturates and benzopiperidine were found active only at toxic dosage. Propranolol and fluanison seem in the preliminary studies to lessen 3 H-thymidine incorporation in vitro at non toxic concentration.