Polypeptide Antibiotic 4205 from a Soil Bacillus

Antibiotic complex 4205, a basic polypeptide, was isolated from a nonsporulating bacillus. It was separated into two components, A and B, each composed of 2,4-diaminobutyric acid, isoleucine, leucine, phenylalanine, serine, and valine, but in different proportions, namely, 4:1:2:1:1:1 and 5:1:3:1:2:2, respectively. There was also an ether-soluble moiety in each that had the characteristics of a fatty acid. This antibiotic differed chemically from other known antibiotics. Both A and B were effective against gram-positive and gram-negative bacteria, cytotoxic for various tissue cell lines, highly toxic for mice by intraperitoneal injection, and toxic for chick embryos by the amniotic and allantoic routes, but not by yolk-sac inoculation. Antibiotic, in amounts sublethal by the allantoic route, inhibited the multiplication of 10 to 100 minimal infective doses of influenza type A, PR8, in embryonated eggs.     

An alternative method for the culture of Diplostomum spathaceum (Trematoda) in chick embryos

Metacercariae of Diplostomum spathaceum were maintained in the allantoic cavities of chick embryos for 15 days. Some embryos had 0.2 ml chicken serum added to the allantoic cavity each day. Although the level of development varied considerably, worms from embryos with added serum developed hind bodies that were substantially larger than those of parasites maintained without added serum. There was no evidence that any worm ingested blood, and only 1 individual, from the serum-augmented group, became ovigerous.     

Comparative Studies on Large- and Small-Plaque-Forming Clones of Newcastle Disease Virus (Miyadera Strain)

The Miyadera strain of Newcastle disease virus (NDV) consisted predominantly of virus particles forming small plaques on monolayers of chick embryo fibroblasts (CEF), and contained small amounts of virus particles forming large plaques. These large- and small-plaque-forming clones of this virus (NDV-L and NDV-S) were isolated. The small size of the NDV-S plaques did not appear to be due to an agar inhibitor. NDV-L produced a much higher yield of infective virus particles in CEF and they were released more completely from the infected cells than were those produced by NDV-S. The yield of infective virus of NDV-L per cell from cultures of CEF was comparable to the yield from the allantoic cells. The infectivity/hemagglutinin ratio for NDV-L from CEF was as high as the ratio for virus from the allantoic cells, but the ratio for NDV-S from CEF was lower. NDV-S demonstrated an autointerference phenomenon in CEF when infected at high multiplicities, but NDV-L did not. Contrary to virus multiplication, NDV-S exhibited a more rapid and marked cytopathic effect on monolayers of CEF than NDV-L. In the allantoic cavity of eggs NDV-S produced slightly higher virus yields than NDV-L. No correlation existed between plaque size of the two viruses and the capacity to induce interferon synthesis or the susceptibility to the action of interferon. The properties of both distinctive plaque isolates were stable on egg passage.     

Schizogony and Gametogony of Eimeria tenella in the Liver of Chick Embryos

SYNOPSIS. Schizogony and gametogony of E. tenella occurred in the liver of chick embryos inoculated intravenously with sporozoites. Gametogony occurred more freely in dexamethasonetreated embryos. Schizonts and gamonts developed within bileduct epithelial cells but many gamonts were also found within cells that appeared to be liver parenchyma type. Schizonts also developed in the chorioallantois of a corticosteroid-treated goose embryo when sporozoites were inoculated via the allantoic cavity.     

Development of calcium reabsorption by the allantoic epithelium in chick embryos grown in shell-less culture

The allantoic sac of the chick embryo functions as a primitive urinary bladder, storing and modifying the excretory fluid produced by the embryo. We have used chick embryos grown in shell-less culture to study the in situ handling of Ca2+ by the allantoic epithelium. Between Days 8 and 13 of incubation (38 degrees C, 5% CO2), the [Ca2+] of the allantoic sac fluid declines from about 1.5 mM to less than 0.3 mM, with most of this Ca2+ reabsorption occurring between Days 10 and 11. In 13-day-old embryos, the allantoic epithelium reabsorbs within 24 hr 85-92% of 45Ca2+ injected into the allantoic sac, while in 9-day-old embryos 45Ca2+ reabsorption is less than 40% by 24 hr. This is evidence for the developmental onset of a Ca2+ reabsorption process in the allantoic epithelium. The allantoic fluid Ca2+ is reabsorbed into the embryo's blood in which the serum [Ca2+] is about 1.5 mM. Also, electrical potential profiles reveal that the serosal (mesenchymal) side of the allantoic epithelium is 15-30 mV positive compared to the mucosal (luminal) side. Thus, by electrochemical criteria this reabsorption process appears to be active.     

Comparison of techniques for the detection of avian infectious bronchitis virus as a contaminant of vaccines

Techniques for detecting various levels of both field and vaccine strains of infectious bronchitis virus in a deliberately contaminated Newcastle disease vaccine were compared using chick embryos, chick kidney cells, chick tracheal organ cultures and chickens with a view to determining the most appropriate method for screening vaccines for freedom from IBV contamination. Techniques examined included detection of abnormalities and deaths in embryos, cytopathic effect in chick kidney cells, ciliostasis in chick tracheal organ cultures and clinical signs and virus isolation in chickens as well as the fluorescent antibody test, negative contrast electron microscopy and serology where appropriate. Results showed that the techniques capable of detecting both strains of infectious bronchitis virus were, in order of sensitivity, the fluorescent antibody test on allantoic cells from infected embryos, ciliostasis and direct electron microscopy of allantoic fluid. One surprising feature was the poor results obtained using chickens. Some detection was achieved with tracheal virus isolation and tracheal organ cultures prepared from inoculated birds and to a lesser extent with histology and clinical signs, but no technique detected the field strain.     

Appearance of brush-border antigens and sucrase in the allantoic endoderm cultured in recombination with digestive-tract mesenchymes

Summary Allantoic endoderm of 3.5-day chick embryos was cultured in recombination with digestive-tract mesenchymes of 6-day chick embryos, and the differentiation of the endoderm was studied, with special attention being given to the appearance of brush-border (BB) antigens and sucrase. Irrespective of the origin of the associated digestive-tract mesenchymes, the allantoic endoderm differentiated into a columnar epithelium, expressing BB antigens and sucrase, and also into a BB antigen-negative pseudostratified or stratified epithelium of cuboidal or columnar cells with PAS or alcian blue staining in the apical portion or a BB antigen-negative stratified squamous epithelium. These results suggest that 3.5-day allantoic endoderm has the potency to differentiate into intestinal and cloacal epithelium.     

Unilateral renal agenesis in chick embryos: a model for chronic renal insufficiency.

Although renal agenesis and dysgenesis are relatively common and significant birth defects, no animal model to date has been utilized to adequately study these developmental pathologies. Blockage of the migration of the mesonephric duct in Day 2 chick embryos results in unilateral renal agenesis (URA) on the operated side, thus providing a model of chronic renal insufficiency. Embryos with URA respond with an increase in the rate of growth of the remaining meso- and metanephric kidney. The allometric scaling of single (left) kidney weight to total body weight in control embryos is KM = 3.48M0.98 compared to KM = 3.02M1.16 in embryos with URA. In addition, embryos with URA exhibit a progressively polycystic mesonephros with distinct glomerulonephritis and expansion of the renal tubules. These renal changes are insufficient for normal urine (allantoic fluid) production and oliguria persists throughout incubation. While mortality is unaffected by URA in embryos up to Day 14 of incubation, there is a steady increase in mortality after Day 14; no chick embryo with URA lives beyond Day 18 of the 21-day incubation period.     

Virostatic activity of 1,10-phenanthroline transition metal chelates: A structure-activity analysis

Structure-activity relationships have been studied for a series of doubly charged, fully co-ordinated, 1,10-phenanthroline transition metal chelates differing in the metal ion or in the number and nature of the substituent groups present on the 1,10-phenanthroline ligand by assaying their ability to inhibit the multiplication of influenza virus in chick allantoic cells in vitro. The most potent compounds are those derived from the highly labile metal ions Cd(II), Cu(II), Zn(II) and Mn(II) or highly lipophilic ligands. The rate of penetration of the active chelate species into the allantoic cell appears to be an important factor determining activity.     

Eukaryotic vectors of Celo avian adenovirus genome,carrying GFP and human IL-2 genes

Recombinant CELO avian adenoviruses carrying green fluorescent protein (GFP) and and human interleukin-2 (IL-2) genes were obtained by homologous recombination in cell culture. The resultant recombinant CELO viruses are reproduced in chick embryos in the renal tubular and chorionic allantoic membrane cells. The ability of CELO vectors to transduce human and animal cells was studied in vitro (in cell cultures) and in vivo (in laboratory animals). GFP gene delivery and expression in recombinant CELO virus in tumors in C57BL/6 mice were for the first time demonstrated for B16 melanoma. Human IL-2 gene expression and protein accumulation in allantoic fluid of chick embryos infected with CELO-IL-2 vector were detected for the first time.     

Propagation of Chandipura virus in chick embryos

Stocks of three Indian Chandipura virus (CHPV) isolates; one isolate from an adult febrile case in 1965 from Chandipura town, Maharashtra, and two isolates from two pediatric encephalitis cases from Andhra Pradesh, 2003 were inoculated in 10-day-old chick embryos by allantoic route. All three virus isolates replicated in chick embryos showing titre of log 10(12) to log 10(13) EID50. The results demonstrated that chick embryos are susceptible to CHPV and virus grows to high titres in this system. Therefore chick embryos can be used as an alternative host system for cultivation and isolation of CHPV as they are less expensive than laboratory animals and have several other advantages over cell cultures. Also this system can be used for the development of vaccine and diagnostic reagents.     

Development of Immune Tolerance in the Chick Embryo to Borrelia hispanica

Varying degrees of immune tolerance were induced in chick embryos at 10, 14, and 18 days of age by inoculation of living or dead Borrelia hispanica in the yolk sac, allantoic cavity, or intravenously. Relative tolerance was measured by responses to challenge with virulent organisms in relation to altered susceptibility to infection and inability to produce agglutinins for B. hispanica or Proteus strain OXK. Challenges were made 1 week posthatching with the controls and chicks that had received dead organisms embryonically, and all chicks and controls were challenged at 5-week intervals from the 5th through the 30th week posthatching. Infections persisted 7 to 12 days in the tolerant chicks without a recurring parasitemia. Control chicks were never infected, and in almost all instances produced agglutinins. Differences in degree and duration of tolerance were observed in relation to the age of the embryo injected and may, or may not, have been related to differences of antigenic mass. Differences in induced tolerance were also observed in the three inoculation routes (intravenous > allantoic cavity > yolk sac, with the first route as the greatest) with chicks that had received dead organisms embryonically, but not with those that had received living organisms. Tolerance was not transmitted to the progeny of tolerant pullets.     

Complement fixation reaction in the typing of influenza viruses isolated in Rio de Janeiro]

The author studied by the complement fixation test the influenza virus strains isolated in Rio de Janeiro during the 1973 epidemic. He prepared immunesera in hamsters by the inoculation of the allantoic fluid from infected chick embryos with each of the 7 isolated strains and the standard strains. The soluble antigens were prepared with the allantoic fluid of infected chick embryos. The tests were identically positive with the A2/Hong Kong/68 and A2/England/72 antigens and negative with the B/Mass/66. The tests were type specific and the behaviour of the A2/Hong Kong/68 and the A2/England/72 and the 7 strains of the isolated viruses was almost the same. They fixed 3 or 4 units of complement. The variants PR8, FM1 and Asia fixed only 2 units of complement.     

Fate of egg white trypsin inhibitor and start of proteolysis in developing chick embryo and newly hatched chick

Trypsin inhibitor and proteolytic activities were studied in incubated eggs, embryos, and newly hatched chicks. After rupture of the secondary seroamniotic suture at 11 days, the trypsin inhibitor content of the albumen gradually passes into the amniotic cavity; from there it is taken up orally by the chick embryo. It is supposed that between 11 and 18 days of embryonic development the trypsin inhibitor passes from the gut to the yolk sac through the vitellointestinal duct. The thin yolk contained only traces of trypsin inhibitor, and the allantoic fluid was entirely free from it. The amylase activity demonstrable in the liquid intestinal contents of the chick embryo indicates the presence of pancreatic secretion. The trypsin inhibitor probably suppresses the proteases not only directly, but also through prevention of the activation of zymogens. Enterocytes of chick embryos showed no morphological indication of the absorption of undigested proteins on histological examination. The cloacal membrane of the newly hatched chick ruptures shortly after the bird has dried up, and the trypsin inhibitor is subsequently eliminated along with the intestinal contents. The intestinal proteolytic enzymes appear immediately afterward. The proteolytic activity appeared regardless of whether the birds were or were not fed. Maximum proteolytic activity was measured in the small intestine of chicks that were fasted for 2 days after hatching. The pattern of proteolytic enzymes as well as their sensitivity to protease inhibitors did not notably differ from that of mammals.     

鸡胚模型在生物研究中的应用进展

实验动物模型在预防、诊断、治疗疾病和探讨疾病的发生机制等方面起到了至关重要的作用。鸡胚发育过程清楚,利用鸡胚本身的结构特点,可作为研究与胚胎发育相关的生物学实验模型。另外,鸡胚绒毛尿囊膜（CAM）血管丰富,是天然免疫缺陷宿主,可作为血管药理学、肿瘤学等方面研究的一个较为理想的实验模型。本文综述了鸡胚模型在生物实验研究中的应用进展。     

Effect of different strains of newcastle disease and fowl-plague viruses on a group of sulphonphthalein dyes

Summary Strains of fowl-plague or Newcastle disease viruses may be easily separated by examining the rate of discharge of certain dyes of the sulphonphthalein group when inoculated with each virus strain into the allantoic fluid of chick embryos.     

Lack of effect of exogenous insulin-like growth factor-I (IGF-I) on chick embryo growth rate

Direct evidence that IGF-I has any significant effect on embryo growth is lacking. We therefore studied the effect of administration of IGF-I on the chick embryo in ovo. Five hundred ng pure IGF-I (purified from human plasma) were given to chick embryos on 2 occasions (7 and 14 d) by injection directly into the allantoic sac. Treated and control (saline injected) chicks hatched on the same day and were killed. IGF-I appeared to reach the tissues as the [35S]-sulphate uptake of treated sternal cartilage was significantly greater than that of control (P less than 0.02). However, there were no significant effects of treatment on total body weight, bone length measurements, organ (lung, liver, heart) weights, muscle DNA, RNA or protein levels. From these results we conclude that administration of exogenous IGF-I to the chick embryo at 7 and 14 d does not stimulate further growth of the chick embryo.     

Development of Leucocytozoon caulleryi in chick embryos infected by biting of Culicoides arakawae through shell membrane.

Chick embryos were infected with Leucocytozoon caulleryi by biting of the midge, Culicoides arakawae, through the shell membrane. Schizonts of L. caulleryi were detected in the chorioallantoic membrane and most of the internal organs of embryos and of chicks after hatching. The development of schizonts was slower in embryos than in chickens. Soluble antigens of L. caulleryi were demonstrated by the precipitation test in the allantoic fluid and blood from the embryos and chicks. No erythrocytic stage of L. caulleryi, however, was observed in any embryo or chick.     

Effect of urea and uric acid on the hemolytic activity of Sendai virus

It was found that haemolytic activity of Fushimi strain of Sendai virus multiplied in allantoic cavity of chicken embryos is independent on its haemagglutinating titer and also on allantoic fluid urea and uric acid content. It was shown in experiments with embryonated eggs that these two compounds have no also influence on haemolytic activity induction in Sendai virus. Moreover, the results of an experiment in which allantoic fluid was replaced by Eagle's liquid suggest that most probably the other components present in allantoic fluid do not also influence the appearance of haemolytic activity of this virus.     

pH-stability patterns of some strains of Newcastle disease and fowl-plague viruses

Summary The strains of fowl-plague virus being tested completely lost their infectivity to chick embryos when stored at p_H 4 for one hour or more while those of the virus of Newcastle disease were all infective to chick embryos when stored at this p_H-value for periods up to 7 days.