"Geographic" Variation in Sensitivity to X-Irradiation in Tribolium: II. Incidence of Developmental Abnormalities

1973 ◽  
Vol 54 (3) ◽  
pp. 521 ◽  
Author(s):  
M. Hani Soliman
Keyword(s):  
Geographic Variation ◽  
Developmental Abnormalities ◽  
X Irradiation

Effects of ionizing radiation on meiotic maturation of frog oocytes

Development ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 87-104
Author(s):  
Yoshio Masui
Keyword(s):  
Ionizing Radiation ◽  
Rana Pipiens ◽  
Meiotic Maturation ◽  
Oocyte Nucleus ◽  
Developmental Abnormalities ◽  
X Irradiation ◽  
Hertwig Effect ◽  
Genomic Function

In an attempt to examine genomic function of the oocyte nucleus during meiotic maturation, the effects of X-irradiation on the oocyte of the frog (Rana pipiens) were studied. When oocytes were irradiated with 6000–36000 R before initiation of maturation, the ovulated eggs frequently failed to be fertilized and the jelly surrounding the unfertilizable eggs was always damaged. However, the egg itself proved to retain the capability of cleaving when a nucleus was transplanted from a blastula. Also, X-irradiated eggs when invested with the jelly from unirradiated frogs recovered their capacity for fertilization. The eggs thus fertilized developed and exhibited abnormalities characteristic of X-irradiation such as arrest of gastrulation and neurulation as well as production of haploidy. Irradiation of oocytes after completion of maturation brought about developmental abnormalities more frequently than irradiation before initiation of maturation. The Hertwig effect was found only when oocytes were irradiated after completion of maturation. However, no qualitative differences were found in the developmental abnormalities produced by irradiation before maturation and those produced by irradiation after maturation.

RECOVERY FROM LETHAL X-RAY DAMAGE DURING DELAYED IMPLANTATION IN THE RAT

1971 ◽  
Vol 51 (4) ◽  
pp. 657-663 ◽  
Author(s):  
W. F. WARD ◽  
R. K. MEYER ◽  
R. C. WOLF
Keyword(s):  
Radiation Effect ◽  
Whole Body ◽  
Irradiation Damage ◽  
Embryonic Survival ◽  
Developmental Abnormalities ◽  
X Ray ◽  
Delayed Implantation ◽  
Stage Of Development ◽  
X Irradiation ◽  
Rate Of Recovery

SUMMARY Rats were exposed to either 300 or 500 röntgen (R) acute whole-body X-irradiation on the 5th day of delayed pregnancy induced by ovariectomy. From 0 to 8 days after irradiation, implantation was induced by the administration of oestrogen. Foetal survival to the 20th day of development was used as an index of radiation effect. If oestrogen was given immediately after exposure to 300 R, or 12 h later, only 30–35% of the embryos survived, significantly less (P < 0·01) than the non-irradiated control values of 74–79%. When implantation was postponed for 24 h or more, embryonic survival ranged from 57 to 64% and was not significantly different from that of controls. After exposure to 500 R X-irradiation, embryonic survival increased linearly from 2% to a maximum of 41% as the interval between irradiation and oestrogen administration increased from 0 to 48 h. Embryonic survival never reached control levels after 500 R, regardless of the interval between irradiation and implantation. The irradiation regimens also induced developmental abnormalities, doubled the incidence of dead foetuses (death at a late stage of development), and significantly reduced foetal and placental weights at autopsy. The results confirm that recovery from potentially lethal X-irradiation damage can occur during delayed implantation, and demonstrate that both the extent and the rate of recovery are functions of the radiation dose.

Electron Microscopic Examination of a Transplantable Rat Mammary Carcinoma

1968 ◽  
Vol 26 ◽  
pp. 20-21
Author(s):  
S. Shirahama ◽  
G. C. Engle ◽  
R. M. Dutcher
Keyword(s):  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Electron Microscopic Examination ◽  
Undifferentiated Carcinoma ◽  
Uranyl Acetate ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
North West ◽  
X Irradiation ◽  
Tissue Specimens

A transplantable carcinoma was established in North West Sprague Dawley (NWSD) rats by use of X-irradiation by Engle and Spencer. The tumor was passaged through 63 generations over a period of 32 months. The original tumor, an adenocarcinoma, changed into an undifferentiated carcinoma following the 19th transplant. The tumor grew well in NWSD rats of either sex at various ages. It was invariably fatal, causing death of the host within 15 to 35 days following transplantation.Tumor, thymus, spleen, and plasma from 7 rats receiving transplants of tumor at 3 to 9 weeks of age were examined with an electron microscope at intervals of 8, 15, 22 and 30 days after transplantation. Four normal control rats of the same age were also examined. The tissues were fixed in glutaraldehyde, postfixed in osmium tetroxide and embedded in Epon. The plasma was separated from heparanized blood and processed as previously described for the tissue specimens. Sections were stained with uranyl acetate followed by lead citrate and examined with an RCA EMU-3G electron microscope.

The Response of Testis Cells to Low Dose X-Irradiation

1981 ◽  
Vol 39 ◽  
pp. 542-543
Author(s):  
D. E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
Joann Stevenson ◽  
S. Black
Keyword(s):  
Electron Microscopy ◽  
Stem Cell ◽  
Light Microscopy ◽  
Dose Level ◽  
Cross Sections ◽  
Low Dose ◽  
Light And Electron Microscopy ◽  
Cellular Responses ◽  
Post Irradiation ◽  
X Irradiation

The response of spermatogonial cells to X-irradiation is well documented. It has been shown that there is a radiation resistent stem cell (As) which, after irradiation, replenishes the seminiferous epithelium. Most investigations in this area have dealt with radiation dosages of 100R or more. This study was undertaken to observe cellular responses at doses less than 100R of X-irradiation utilizing a system in which the tissue can be used for light and electron microscopy.Brown B6D2F1 mice aged 16 weeks were exposed to X-irradiation (225KeV; 15mA; filter 0.35 Cu; 50-60 R/min). Four mice were irradiated at each dose level between 1 and 100 rads. Testes were removed 3 days post-irradiation, fixed, and embedded. Sections were cut at 2 microns for light microscopy. After staining, surviving spermatogonia were identified and counted in tubule cross sections. The surviving fraction of spermatogonia compared to control, S/S0, was plotted against dose to give the curve shown in Fig. 1.

Eds Of Radioactive Particles By Self-Induced Fluorescence

1990 ◽  
Vol 48 (2) ◽  
pp. 238-239
Author(s):  
Gregory L. Finch ◽  
Richard G. Cuddihy
Keyword(s):  
Electron Beam Irradiation ◽  
Nuclear Reactor ◽  
X Rays ◽  
Reactor Accident ◽  
Internal Radiation ◽  
X Ray ◽  
External Sources ◽  
X Irradiation ◽  
Available Information ◽  
Individual Particles

The elemental composition of individual particles is commonly measured by using energydispersive spectroscopic microanalysis (EDS) of samples excited with electron beam irradiation. Similarly, several investigators have characterized particles by using external monochromatic X-irradiation rather than electrons. However, there is little available information describing measurements of particulate characteristic X rays produced not from external sources of radiation, but rather from internal radiation contained within the particle itself. Here, we describe the low-energy (< 20 KeV) characteristic X-ray spectra produced by internal radiation self-excitation of two general types of particulate samples; individual radioactive particles produced during the Chernobyl nuclear reactor accident and radioactive fused aluminosilicate particles (FAP). In addition, we compare these spectra with those generated by conventional EDS.Approximately thirty radioactive particle samples from the Chernobyl accident were on a sample of wood that was near the reactor when the accident occurred. Individual particles still on the wood were microdissected from the bulk matrix after bulk autoradiography.

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