Following the intra-allantoic injection of influenza A virus in embryonated eggs, a latent period of 4 to 6 hours has been observed, during which little or no active virus can be recovered from any of the embryonic fluids or tissues (1, 2). Microbial toxins probably exert their effect by altering cellular metabolism. Pappenheimer and Hendee have suggested that the diphtheria toxin, for example,...

Polyamines (putrescine, spermidine, and spermine) are essential for placental growth and angiogenesis. However, little is known about changes in polyamine synthesis associated with development of the ovine conceptus (embryo/fetus and associated placental membranes). We hypothesized that rates of placental polyamine synthesis were maximal during the rapid placental growth that occurs in the firs...

The ontogeny of insulin-like growth factor-I (IGF-I) embryonic and extra-embryonic tissue concentrations were determined in the developing turkey embryo. At 2-d intervals, starting on Day 6 of incubation, individual tissues (n = 8 for each stage of incubation) were removed, weighed, pulverized, and extracted in 1 M acetic acid for IGF-I determination. Amniotic and allantoic fluid were collected...

Determination of the avian influenza (AI) status of a flock has traditionally been done by detection of serum antibodies. However, for many diseases, detection of antibodies in egg yolk has been effective in monitoring the disease status of laying flocks. This study compared the utility of egg yolk vs. serum for determining AI status in laying hen flocks. Specific-pathogen-free white leghorn he...

Two component traits of litter size of pigs, ovulation rate and embryonic survival, were examined in Meishan and composite white crossbred gilts and sows. At puberty, an ovulation rate of 12.5 was similar for Meishan (118 +/- 3 d of age) and crossbred gilts (217 +/- 3 d of age). The number of corpora lutea (CL) increased (4.3 CL) markedly (P < .01) from puberty to the sixth estrous period (220 ...

Electron microscopic study has revealed the morphological entity responsible for the rise in viral hemagglutinin observed in brains of mice after intracerebral inoculation of non-neurotropic strains of influenza virus. This rise in hemagglutinin, although dependent on inoculation of fully infectious virus, is not associated with an increase in infectious titer. The hemagglutinating principle is...

To detect the presence of infectious bronchitis virus (IBV) in infected allantoic fluid (AF) of SPF embryonated eggs rapid hemagglutination (HA) activity after treatment with neuraminidase enzyme was used. Twenty IBV suspected materials were inoculated in SPF embryonated eggs via chorioallantoic cavity. Harvested AFs were treated with neuraminidase enzyme and the presence of IBV was detected by...

Mukteswar strain of Newcastle disease (ND) virus was propagated in 9-day-old embryonated eggs via allantoic route. The harvested allantoic fluid with haemagglutination (HA) titre of 1024 (EID50 10) was inactivated using 0.1 percent formalin solution. Two experimental vaccines were prepared in light mineral oil with aqueous to oil ratio of 1:2 ( MK-VAC-I) and 1:4(MK-VAC-II).The hydrophile lipoph...

The R2B strain of virus of new castle disease virus (NDV) was propagated in 9-11 day old embryonated chicken eggs via allantoic cavity route and after seven serial passages virus was purified from allantoic fluid. Purified virus was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis which yielded six major polypeptides ranging from 38-200 kDa. Protein fractions, corresponding...

In cloned pregnancies, placental deficiencies, including increased placentome size, reduced placentome number, and increased accumulation of allantoic fluid, have been associated with low cloning efficiency. To assess differences in paracrine and endocrine growth regulation in cloned versus normal bovine placentomes and pregnancies, we have examined the expression of insulin-like growth factor ...