PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Dead embryos”

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 19 recordsLinked to original sources
PubMed2026

Salmonella Pullorum strain SPullorum-YN-07 from dead embryos of Yanjin black-bone chickens: Complete genome with IncFII(S) and Col(pVC) plasmids and pathogenicity.

Salmonella Pullorum is a host-adapted pathogen that causes Pullorum disease in chickens and can be vertically transmitted via eggs, leading to embryonic mortality. The susceptibility and vertical transmission of S. Pullorum may vary among chicken breeds, yet genomic characterization of strains from dead embryos of indigenous breeds remains limited. This study isolated and characterized a Gram-negative short rod, designated Salmonella Pullorum strain SPullorum-YN-07, from dead embryos of Yanjin black-bone chickens, a native breed in Yunnan, China. The strain formed colorless colonies on MacConkey agar and red, non-H2S colonies on XLD agar, with biochemical reactions consistent with the genus Salmonella. Whole-genome sequencing using Illumina and PacBio platforms generated a complete genome consisting of one circular chromosome and four circular plasmids; plasmid replicon types IncFII(S) and Col(pVC) were identified in two of the plasmids. On the chromosome, a total of 340 virulence-associated genes were detected, including those involved in secretion systems, adhesion, motility, and immune modulation. Resistance gene analysis identified the acquired aminoglycoside resistance gene aac(6')-Iaa, alongside multiple intrinsic resistance determinants related to efflux pumps and target alteration. Multilocus sequence typing (MLST) assigned the strain to sequence type ST92, and core-genome phylogenetic analysis confirmed its clustering within the Salmonella Pullorum lineage. In a chick infection model, the strain induced depression, white diarrhea, and growth retardation, with clinical scores peaking at 10 days post-infection and a mortality rate of 10%. Bacterial colonization was highest in the cecum, and histopathological lesions were observed in the liver, spleen, and cecum. This study provides the first complete genomic characterization and pathogenicity assessment of an S. Pullorum strain isolated from dead embryos of Yanjin black-bone chickens, offering a foundation for understanding host-pathogen interactions in indigenous breeds and assessing cross-transmission risks to commercial poultry populations.

Complete genome↗
PubMed1976

The resistance and carrier status of meat-type hens exposed to Mycoplasma synoviae.

Forty-eight 32-week-old meat-type females, free from Mycoplasma synoviae (Ms.) and Mycoplasma gallisepticum (Mg.) were aerosol exposed with a 24-hour broth culture of Ms. 1331 and placed in 3 pens. 16 birds per pen. Two males were placed in each of the 3 pens and used as contact birds. All birds were bled at 2, 4, 7, 10, 14, 24, 26, and 30 weeks post Ms. exposure. After the 24-week bleeding, the females were equally divided into 4 pens. All females in 2 of the pens were given a foot pad injection of 0.3 ml. of Ms. 1331 broth culture. Ms. isolation attempts were made from the trachea of all birds at 2, 14, and 24 weeks post Ms. exposure. Ms. isolation attempts were made from all eggs produced, either from the allantoic fluid and egg yolk of 17- or 18-day-old embryos, dead embryos, and infertile eggs, or from the tracheas of day-old progenies. Each day-old progeny was bled. Ms. and Mg. serum plate tests were conducted on the serums from the progeny and adult birds from each bleeding. Ms. hemagglutination-inhibition (HI) tests were conducted on the serums of the adult birds. In the Ms.-exposed birds, the geometric mean HI titer of the serums from each bleeding rose significantly over the previous bleeding. The percentages of Ms. serum plate reactions increased with length of time after Ms. exposure. There were false Mg. serum plate reactions in the early stages of Ms. infection. A foot pad challenge with a broth culture of Ms. 1331 24 weeks after Ms. exposure did not significantly increase the geometric mean HI titer over the Ms. exposed birds that did not have a Ms. foot pad challenge. Ms. was isolated from the trachea of 91.6%, 100%, and 100% of the Ms.-exposed birds at 2, 14, and 24 weeks after Ms. exposure, respectively. There were 35 Ms. isolates from 575 attempts from 17- or 18-day embryos, dead embryos, or infertile eggs, and 7 Ms. isolates from 67 attempts from the trachea of day-old progenies. All isolates were made from eggs collected from 6 through 31 days afer Ms. exposure. No isolations were made from 1760 attempts made from eggs collected from 32 through 210 days after Ms. exposure, including eggs collected from Ms. foot pad-challenged birds at 168 days after Ms. exposure. There were 312 broilers reared from eggs collected from the 22 through 24 weeks after Ms. exposure. The broilers were marketed at a federally inspected poultry processing plant. Their records showed 3 birds condemned for septicemia-toxemia, but none were condemned for air-sacculitis or synovitis. Twenty-four serums from the broilers that were positive to Ms. or Mg. serum plate tests were all negative to the Ms. and Mg. HI tests. Ms. serum plate reactors began to show up in the day-old progeny from eggs collected beginning on the 76th day after Ms. exposure. There were 16.0% (80/500) positive to the Ms. serum plate test from eggs collected from the 76 through 126 days after Ms. exposure and 14.0% (52/372) from eggs collected from the 169 through 210 days after Ms. exposure.

Animals↗
PubMed1978

[Abortive effect of autologous anti-alpha-fetoprotein antibodies in the rat].

Female Commentry Rats 80--85 days old, were immunized by 5 intramuscular injections of Mouse alphafetoprotein (AFP) and then mated. After fertilization a supplementary injections was administered. The animals were bled at different times and killed immediately after the last bleeding on the 19 or 20th day of gestation. Titers of AFP and of autologous anti-AFP antibodies in the maternal blood were determined as well as the AFP concentration in the pooled amniotic fluids from live embryos of each litter. Compared to non-immunized control series, the total of live and dead embryos per litter in animals immunized with Mouse AFP showed no difference. However, the number of live embryos was on the average 50% lower than that in the control series. The serum titers of AFP and of antibodies to autologous AFP in immunized pregnant Rats bearing dead embryos decreased concomitantly with the number of live embryos. The results reported herein demonstrate that the presence of anti-autologous AFP antibodies in pregnant Rats correlates with the interruption of development in a significant proportions of embryos. This suggests that certain spontaneous abortions in the Rat and perhaps in other mammals can be explained by the rupture of immunological tolerance to autologous AFP.

Abortion, Spontaneous↗
PubMed1978

Dominant lethal effects of triethylenemelamine in the guppy Poecilia reticulata.

The need to screen potential chemical pollutants for mutagenicity has increased with the increasing volume of such materials being introduced into natural water. The present study demonstrates the utility of a fish, the guppy (Poecilia reticulata), as a model test system in which water-borne chemical mutagens may be assayed for dominant lethal effects. Mature male guppies were injected with three doses of triethylenemelamine (0.1, 0.2 and 0.4 mg/kg) in addition to a control sham treatment. Each male was subsequently mated to virgin females. In an alternative test, male fish were allowed to swim in triethylenemelamine solutions of known concentration for a period of 24 h prior to being mated to virgin female guppies. 10 days following matings, females were dissected, and numbers of live and dead embryos were recorded. Significant dose effects were demonstrated by analysis of variance techniques in both the injection and the emersion tests with the results showing higher percentages of dead embryos and lower total number of embryos with increasing doses of TEM.

Animals↗
PubMedDate not supplied

Virulence of Escherichia coli strains for chicken embryos.

The virulence of 66 Escherichia coli strains was evaluated in 12-day-old chicken embryos inoculated by the allantoic route. The index of virulence used was the proportion of dead embryos within 3 days of inoculation. The strains were classified into "highly virulent," "moderately virulent," and "avirulent" groups. Although both virulent and avirulent strains grew equally well in vivo in the allantoic and yolk sacs, virulent E. coli invaded the whole embryo but avirulent ones failed to do so.

Animals↗
PubMed1976

[Production of a vaccine against pseudoplague in poultry using the La Sota strain].

Comparative investigations were carried out on the quality and quantity of a vaccine against Newcastle disease in birds with the La Sota strain, obtained after the routinely applied productional technology or after some of the author's modifications of the method. The addition of penicillin, kanamycin, oleandomycin or chlorocid to the virus intended for an archive showed on unfavourable effect on the development of the chick embryos used; there was no such effect on the La Sota strain multiplying in them either. The industrial production of this vaccine with the addition of the above entibiotics used either alone or in combination had favourably influenced the sterility of the virus suspension. Data showed that at to and fro moving of the embryos following infection with the virus every two hours at an angle of 150 degrees C the number of dead embryos at the 76th hour was lower. The agglutination-reaction titer was considerably higher. A proof of high immunogenicity of the vaccines obtained was also the infectious titer of the virus in 11-old chick embryos--log 10(-9), on an average. On the 11th day of incubation the embryos infected with the La Sota strain of the virus had greater amounts of alanto-amnionic fluid than those kept in the incubator and infected on the 10th day. At infecting on the 11th day of age greater amounts of virus suspension were obtained without lowering of its infectious titer; thus, its immunogenic properties remained unchanged.

Age Factors↗
PubMed1976

Effect of selenium and mercury on gross morphology and histopathology of chick embryos.

Gross lesions of selenium toxicity in chick embryos included webbed, fused, and curled toes; cracked, crooked, and shortened beaks and gastroschisis. Mercury injection on day 3 of incubation caused leg defects but older embryos were much less susceptible. Histopathological studies showed that injection of selenium as selenite caused dissociation of hepatic cells, particularly around the central veins. Glomeruli of affected kidneys were enlarged, and in each glomerulus the lumen of the capillary tuft was dilated and the space of Bowman widened. Epithelial cells of the proximal convoluted tubules were detached from the basement membranes. Injection of mercury as chloride resulted in liver pathology in the late dead embryos which included dilated central veins and sinusoids. The cytoplasm of many hepatic cells was vacuolated. Foci of hemorrhages were observed in all liver lobes. In the kidneys, the renal corpuscles showed either shrinkage or enlargement. They seemed to be in the process of degeneration and disintegration. Sclerotic glomeruli were characterized by disappearance of Bowman's space and clumping of the glomerular tuft. Combined treatment with selenium and mercury resulted in liver pathology similar to that observed in mercury toxicity. The hepatic cell dissociation seen in selenium treated embryos was not observed following the combined treatment. In the kidneys the combined treatment resulted in typical lesions of both selenium and mercury toxicity.

Abdomen↗
PubMed1975

[Investigations on the mutagenic effect of triethylenemelamine (TEM) on early embryonic tissue and bone marrow of the rat by chromosome analysis (author's transl)].

Female rats were treated with triethylenemelamine (Tretamine; TEM) with a dose of 0.4 mg/kg body weight and 0.6 mg/kg body weight respectively on days 1, 2, 3; 3, 4, 5 or 6, 7, 8 post coitum. The animals were slaughtered on day 9 or pregnancy. Corpora lutea and living and dead embryos were counted to estimate embryonic loss. Thereafter chromosome-analysis of bone marrow cells and embryonic tissue took place. Highter TEM dosage increased the rate of embryonic loss. It increased from 28.1% with a dose of 3 X 0.4 mg TEM to 75.7% with 3 X 0.6 mg TEM. The level of embryonic loss depends on the time of treatment during different stages of early gestation. It was highest on the first 3 days and lowest on days 6-8 of gestation (0.4 mg TEM on -ays 1, 2, 3 p.c., 71.8%; 0.4 mg TEM on days 6, 7, 8 p.c., 2.9%). By the chromosome analysis, early embryonic tissue seemed to be more sensitive to TEM than bone marrow cells. The highest rates of numerical (35.7%) and (3 X 0.4 mg TEM). A higher dose induced a negative dose-effect, the frequency of aberrations decreased (3 X 0.6 mg TEM, 29% NUMERICAL AND 1.2% STRUCTURal aberrations). With increased embryonic loss (from 28.1% to 75%) structural aberrations decreased (from 5.7% to 1.2%). The time of treatment p.c. was highly correlated with the frequency of aberrations. It was highest with TEM application on days 6, 7, 8 of pregnancy; at the same time the mortality rate was lowest. The same tendencies were noted in the investigation of the chromosomes from bone marrow cells.

Animals↗
PubMed1978

Chemical and radiation induced late dominant lethal effects in mice.

Although theoretically expected, experimental data to date have not shown dominant lethal expression to occur throughout the developmental period. Specifically, late post-implantation effects have not been demonstrated. We routinely use an experimental technique in which parental females mated to mutagenically treated males are allowed to give birth and wean their litter, and their uterine horns are then inspected for uterine scars indicative of live and dead embryos. In a number of experiments in which males were mutagenically treated with either chemicals or X-irradiation, a discrepancy was observed between the number of live embryos as determined by the scar technique and the number of live observed at birth, suggesting the possibility of embryonic losses at a late stage in development. Initial analyses showed that mutagenic treatment increased the percentage of these late losses. These differences were statistically significant in 2 of 3 analyses. Factors affecting statistical significance and an understanding of dominant lethal mutations are discussed.

Animals↗
PubMed1975

Effects of electromagnetic fields on fecundity in the chicken.

Egg production was reduced when young laying hens were kept in contact with metal cages while being continuously exposed to the following cw fields: a vhf field at a frequency of 260 MHz, with an incident power that decreased from 100 to 4mW during the experiment; a uhf field at a frequency of 915 MHz, with an incident power of 800 mW during the first 2.5 weeks, zero during the following week, and 200 mW for the remainder of the experiment; a uhf field at 2.435 GHz, with an incident power of 800 mW; an elf electric field at a frequency of 60 Hz, with a calculated value of field strength of 1600 V/m; an elf magnetic field at 60 Hz, with a value of magnetic flux density of 1.4G. With the exception of the hens exposed to the uhf field at 915 MHz, all other treated groups laid significantly less eggs than the controls (p smaller than or equal to 0.01). This reduction (similar 15% less than the controls) began with the first 4-week production period. The egg production curves for the hens exposed to the vhf field at 260 MHz and to the uhf field at 2.435 GHz were approximately the same beginning with the sixth week of production, and they maintained comparable production levels for the remainder of the experiment. An 8% total drop in production also was experienced in the group of birds exposed to the 915-MHz field, which pulsed because of equipment failure. Egg production rate curves for the birds in the elf electric and magnetic fields were substantially different from those exhibited by birds in the other electromagnetic fields. The birds in the E-field regained a production level comparable to the controls after 11 weeks production, whereas those in the B-field dropped to 31% production, which was approximately 40% poorer than the controls by the twelfth week of production. Fertility of cocks and hens was not affected by continuous low-power vhf and uhf near-zone electromagnetic exposure or elf electric or magnetic field treatment. Fertility was exceptionally good, except for the controls and the hens exposed to the elf electric field. The hatchs of fertile and of total eggs were not significantly influenced by exposure to any of the five fields. A considerably lower incidence of male chicks was noted in the elf magnetic field treatment (32.3%). The sex ratio in the other groups appeared to be relatively normal. No macroscopic abnormalities attributable to treatments were noted in the chicks hatched or in the dead embryos.

Animals↗
PubMed1979

Teratogenic effects of a single oral administration of methylmercuric chloride in mice.

The teratogenic effects of methylmercuric chloride (MMC) given orally as a single dose to pregnant ICR mice on day 10 of gestation were examined. The doses tested were 25, 20, 15 and 10 mg/kg. Controls received distilled water orally. Each group consisted of 20 females. Fetuses were taken on day 18 of gestation for teratological study. The number of resorbed or dead embryos was moderately increased in the 25 mg/kg group. Fetuses from dams given 25, 20 and 15 mg/kg MMC weighed significantly less than those in the control group. Many fetuses with malformations were observed in the treated groups; cleft palate occurred in 100, 58.6 and 28.0% of fetuses from dams given 25, 20 and 15 mg/kg MMC, respectively (statistically significant). Hydronephrosis appeared in 23.8 and 18.5% of fetuses from dams given 25 and 20 mg/kg MMC, respectively (statistically significant). Skeletal variations, incomplete ossification of sternebrae, for example, were also observed in the treated groups. These results indicate that MMC is teratogenic so far as cleft palate is concerned and embryotoxic in ICR mice.

Abnormalities, Drug-Induced↗
PubMed1975

Genetics of cleft palate in chickens and the relationship between the occurrence of the trait and maternal riboflavin deficiency.

Reciprocal crosses were made between a New Hampshire line of chickens free of cleft palate and affected individuals of a highly inbred S.C.W. Leghorn line having 30 to 50% incidence of cleft palate. The frequency of cleft palate was observed under normal and riboflavin deficient maternal nutrition for the reciprocals of the F1, F2, and backcross to the cleft palate line. Two cases of cleft palate were found in dead embryos of 1368 F1 observations. These may not have represented the genetic trait under study. The response of egg hatchability to riboflavin deficiency was shown to be earlier for cleft palate line hens than for F1 hens, but no maternal effects were found for cleft palate incidence. The frequency of cleft palate in the F2 increased from 0.7% during normal maternal nutrition, to 4.4% during maternal riboflavin deficiency. A similar increase from 8.0% to 12.4% was seen in the backcross progeny. The cleft palate trait was found to be semi-lethal, with mortality associated with severe expression of the trait. No significant sex differences in cleft palate incidence was found in the F2 or backcross generations. The F2 and backcross cleft palate data fit models of genetic control by 3 recessive loci during normal maternal nutrition, and 2 recessive loci during maternal riboflavin deficiency. Penetrance was indicated to be under additive genetic control, and the average was calculated to be between 50 and 75% for all cases. The loss of relevance of one locus during maternal riboflavin deficiency was interpreted to indicate that the homozygous recessive condition at that locus gave disturbed riboflavin metabolism. It was further interpreted to explain the increased occurrence of some traits during teratogenic circumstances as due to the increased probability of obtaining recessive homozygosity at (n - 1) loci compared to (n) loci, and that the role of teratogens in some traits may be in mimicking specific genetic components of the traits.

Animals↗
PubMed1977

The selenium requirements of the hen and effects of a deficiency.

Hens were fed a diet low in selenium made up mostly of corn and torula yeast. Egg production and hatchability increased significantly when selenium was supplemented, while the percentage of infertile eggs and early dead embryos decreased. Anemia also resulted from the deficiency. A total of .05 mg. selenium per kg. (.04 from the basal diet plus .01 supplemental) was adequate to prevent signs of deficiency in a diet which contained no supplemental vitamin E or antioxidant. In a second experiment the anemia was classified as macrocytic.

Anemia↗
PubMed1992

Influence of Coxiella burnetii infection of male mice on their offspring.

The dramatic spread of Q fever in Poland among cattle kept in isolation from natural environment (ticks, wild animals) has suggested the possibility that the infection may also be transmitted sexually. To test this hypothesis series of experiments have been performed in controlled laboratory conditions. Male mice infected with C. burnetii were allowed to mate with healthy female mice. On day 18 of pregnancy serum IgM antibodies to C. burnetii antigens and bacteria in spleen, liver and placenta were detected. The influence of C. burnetii transmission between parents of their offspring was investigated. It has been found that C. burnetii infection in males diminish the number of fertilized females. Their litters are fewer in number and the number of dead embryos is increased.

Animals↗
PubMed1992

Some biological effects of Bayluscide on Physa acuta and Helisoma duryi.

The fecundity, viability and the size of egg-masses were studied in Physa acuta and Helisoma duryi snails treated with 1 ppm Bayluscide for two hours. Bayluscide application caused significant and highly significant reduction in the fecundity of both Physa acuta and Helisoma duryi. However, an increase in the fecundity was observed for both treated snails in few days after exposure. Moreover, Bayluscide did not lead to stoppage of egg laying at any day of experiment. Bayluscide caused a reduction in the viability of egg-masses produced by treated Physa acuta or Helisoma duryi snails since they produced higher numbers of abnormal eggs containing dead embryo. Moreover, application of 1 ppm Bayluscide for two hours against Physa acuta caused a decrease in the size of egg-masses produced by treated snails. This is expressed by the production of higher percentage of egg-masses containing small numbers of eggs as compared with those masses produced by control snails.

Animals↗
PubMed1976

Twin pigeon embryos.

Twin pigeon embryos were found on incubation day 18 in a pipped egg. The egg was pipped at the small end. The embryos were dead. Removal of a portion of the shell allowed removal of one embryo and revealed the second one. Both appeared normal in development and size.

Animals↗