THE IMMEDIATE EFFECTS OF SEVERE LOCAL X IRRADIATION ON THE LIVER OF THE HAMSTER

1952 ◽  
Vol 30 (6) ◽  
pp. 571-577
Author(s):  
Katherine E. Livingstone ◽  
David J. McCallion
Keyword(s):  
Experimental Studies ◽  
Liver Parenchyma ◽  
Liver Cells ◽  
The Body ◽  
Field Size ◽  
Cyclic Variation ◽  
X Rays ◽  
X Irradiation ◽  
Parenchymal Cells ◽  
Cyclic Fluctuation

Opinions regarding the radiosensitivity of the liver, based on clinical and experimental studies, differ widely. No comprehensive study of the immediate effects of severe local X irradiation upon the cytology of the liver parenchyma has been previously undertaken. In the present investigation cytological studies were made upon the livers of hamsters at 4-hr. intervals over a 24-hr. period. It was demonstrated that the amounts of cytoplasmic basophilia, glycogen, and sudanophilic fat show a cyclic variation over the 24-hr. period studied. Adult hamsters were exposed to X rays at the rate of 495 r. per minute with a total dosage of 2000 r. The field size over the liver was 4 cm. by 2 cm. with the rest of the body protected by a lead shield. Following irradiation the animals were sacrificed, two at a time, at 4 hr. intervals over a 24-hr. period. The amounts of basophilic material in the cytoplasm of the parenchymal cells of the liver were considerably decreased at 8 hr. and at 16 hr. after irradiation. At other times the cytoplasmic basophilia of the irradiated liver cells was approximately as dense as that of the control animals. The density of cytoplasmic basophilia showed a cyclic variation approximating that of the controls. The amount of glycogen in the irradiated livers was very much decreased, but still showed a cyclic fluctuation. There was a striking decrease in the amount of sudanophilic fat in the liver cells following irradiation. The results indicate that severe local X irradiation of the liver of the hamster has immediate effects directly upon that organ, resulting in a disturbance of its normal physiological activities.

Emergency Medical Services Backboard With a Pressure Dispersion Liner

2009 ◽  
Author(s):  
Matthew R. Henschen ◽  
Adam L. Koesters ◽  
Jonathan Harvey ◽  
Gregory Nemunaitis ◽  
Mehdi Pourazady ◽  
...  
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
X Rays ◽  
Interface Pressure ◽  
Light Pressure ◽  
Average Maximum ◽  
Cord Injury ◽  
Pressure Spike ◽  
Bed Sores ◽  
Trauma Victims

Spinal immobilization is of utmost importance when caring for major trauma victims. Because of the potential for spinal cord injury, trauma victims must be secured to a rigid backboard. Patients are held in position by placing blocks on either side of their head, straps across their forehead, chest, and legs. The goal of using a hard backboard is to reduce the chances of damaging the victim’s neurological functions because of movement of unstable or injured vertebrae. These backboards serve their function of patient immobilization but present another problem for the patient. They have been associated with a skin breakdown condition called decubitus ulcers (bed sores). Bed sores are areas of damaged skin and tissue that develop when sustained pressure causes a restriction of blood circulation to vulnerable parts of the body. Without adequate blood flow, the affected tissue dies. Some patients may be secured to these boards for up to four hours waiting to undergo x-rays. This is more than enough time for ulcers to reach Stage IV which is the deepest and most destructive ulcer. The incidence of pressure ulcers in newly admitted patients has been reported as high as 59% and 50% have been reported at the sacral region [1, 2]. In experimental studies performed on dogs it has been shown that a constant pressure of only 60mmHg for one hour is enough to cause irreversible tissue damage [3]. When the patients are on the backboards it has been shown that there is often a high pressure spike at the sacral prominence where average maximum interface pressure spike of 260mmHg have been noted. When a thin but very heavy gel pad was added to the backboard, the sacral interface pressure was reduced to an average maximum pressure of 188 mmHg [4]. The objective of this project is to develop a backboard with a light pressure dispersion liner to reduce interface pressures on pressure sensitive areas in the supine position.

Volitional Activity Response of Rats to Partial-Body X-Irradiation

1957 ◽  
Vol 189 (1) ◽  
pp. 15-20 ◽  
Author(s):  
D. C. Jones ◽  
D. J. Kimeldorf ◽  
G. K. Osborn ◽  
T. J. Castanera ◽  
D. O. Rubadeau
Keyword(s):  
The Body ◽  
Transient Increase ◽  
Whole Body ◽  
X Rays ◽  
Control Activity ◽  
Initial Decrease ◽  
Significant Depression ◽  
X Irradiation ◽  
Partial Body ◽  
High Doses

Shielding of the abdomen during x-irradiation was used to test the hypothesis that the initial decrease in the volitional activity of rats observed after whole-body x-irradiation is related primarily to irradiation of the abdomen. Exposure of the abdomen to 200 r, or of the remaining half of the body to 200 or 600 r did not result in a significant depression in activity. When the abdomen was exposed to 600 or 750 r, however, a depression in activity was observed, with a minimum on the 3rd day postirradiation, followed by increasing activity. When animals were exposed to relatively high doses (1500 or 2000 r) with the abdomen shielded, or with only the head exposed (1500 r), there was an immediate depression in activity on the 1st day postirradiation, then a transient increase in activity to values equal to or well above control levels, followed by a rapid decrease below control activity, and then by increasing activity. The transient increase above control activity was duplicated by pair-feeding nonirradiated animals to the head-exposed group. It appears that the initial decrease in volitional activity may be mediated by altered gastrointestinal function, particularly with respect to the 3rd day postirradiation. In abdomen-shielded or head-exposed animals subjected to higher doses of x-rays, the transient rise in activity appears to be related to restricted food intake, probably as a result of radiation damage of the oral mucosa. The subsequent depression in volitional activity in these animals may be related to central nervous system injury.

scholarly journals Disposition of the Acyclic Nucleoside Phosphonate (S)-9(3-Hydroxy-2-Phosphonylmethoxypropyl)Adenine

1998 ◽  
Vol 42 (5) ◽  
pp. 1146-1150 ◽  
Author(s):  
Martin K. Bijsterbosch ◽  
Louis J. J. W. Smeijsters ◽  
Theo J. C. van Berkel
Keyword(s):  
Cell Types ◽  
Hepatic Uptake ◽  
Liver Cells ◽  
The Body ◽  
Total Uptake ◽  
Parenchymal Liver ◽  
Acyclic Nucleoside ◽  
Parenchymal Cells ◽  
Acyclic Nucleoside Phosphonate

ABSTRACT The acyclic nucleoside phosphonate (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA] has been shown to be active against pathogens, like hepatitis B viruses and Plasmodiumparasites, that infect parenchymal liver cells. (S)-HPMPA is therefore an interesting candidate drug for the treatment of these infections. To establish effective therapeutic protocols for (S)-HPMPA, it is essential that the kinetics of its hepatic uptake be evaluated and that the role of the various liver cell types be examined. In the present study, we investigated the disposition of (S)-HPMPA and assessed its hepatic uptake. Rats were intravenously injected with [3H](S)-HPMPA, and after an initial rapid distribution phase (360 ± 53 ml/kg of body weight), the radioactivity was cleared from the circulation with a half-life of 11.7 ± 1.4 min. The tissue distribution of [3H](S)-HPMPA was determined at 90 min after injection (when >99% of the dose cleared). Most (57.0% ± 1.1%) of the injected [3H](S)-HPMPA was excreted unchanged in the urine. The radioactivity that was retained in the body was almost completely recovered in the kidneys and the liver (68.4% ± 2.5% and 16.1% ± 0.4% of the radioactivity in the body, respectively). The uptake of [3H](S)-HPMPA by the liver occurred mainly by parenchymal cells (92.1% ± 3.4% of total uptake by the liver). Kupffer cells and endothelial cells accounted for only 6.1% ± 3.5% and 1.8% ± 0.8% of the total uptake by the liver, respectively. Preinjection with probenecid reduced the hepatic and renal uptake of [3H](S)-HPMPA by approximately 75%, which points to a major role of a probenecid-sensitive transporter in the uptake of (S)-HPMPA by both tissues. In conclusion, we show that inside the liver, (S)-HPMPA is mainly taken up by parenchymal liver cells. However, the level of uptake by the kidneys is much higher, which leads to nephrotoxicity. An approach in which (S)-HPMPA is coupled to carriers that are specifically taken up by parenchymal cells may increase the effectiveness of the drug in the liver and reduce its renal toxicity.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

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.

scholarly journals THE INTERCELLULAR DISTRIBUTION OF MUTATIONS INDUCED IN OOCYTES OF DROSOPHILA MELANOGASTER BY CHEMICAL AND PHYSICAL MUTAGENS

Genetics ◽  
1979 ◽  
Vol 92 (1) ◽  
pp. 151-160
Author(s):  
H Traut
Keyword(s):  
Drosophila Melanogaster ◽  
Mitomycin C ◽  
Mutation Frequency ◽  
Lethal Mutation ◽  
X Rays ◽  
Mutagenic Treatment ◽  
X Chromosomes ◽  
Recessive Lethal ◽  
Lethal Mutations ◽  
X Irradiation

ABSTRACT When females of Drosophila melanogaster are treated with chemical or physical mutagens, not only in one but also in both of the two homologous X chromosomes of a given oocyte, a recessive sex-linked lethal mutation may be induced. A method is described that discriminates between such "single" and "double mutations." A theory is developed to show how a comparison between the expected and the observed frequency of double mutations yields an indication of the intercellular distribution (random or nonrandom) of recessive lethal mutations induced by mutagenic agents in oocytes and, consequently, of the distribution (homogeneous or nonhomogeneous) of those agents.—Three agents were tested: FUdR (12.5, 50.0 and 81.0,μg/ml), mitomycin C (130.0 μg/ml) and X rays (2000 R, 150 kV). After FUdR feeding, no increase in the mutation frequency usually observed in D. melanogaster without mutagenic treatment was obtained (u=0.13%, namely three single mutations among 2332 chromosomes tested). After mitomycin C feeding, 104. single and three double mutations were obtained. All of the 50 mutations observed after X irradiation were single mutations. The results obtained in the mitomycin C and radiation experiments favor the assumption of a random intercellular distribution of recessive lethal mutations induced by these two agents in oocytes of D. melanogaster. Reasons are discussed why for other types of mutagenic agents nonrandom distributions may be observed with our technique.

Experimental Studies on Diesel Engine with Piston Crown Modification Using an Optimum Alternative Fuel

2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Air Gap ◽  
The Body ◽  
Injection Timing ◽  
Positive Trend ◽  
Piston Crown ◽  
Karanja Oil

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.

Late Stage Decomposition of Embalmed Cadavers

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Pilar Mata Tutor ◽  
Catherine Villoria Rojas ◽  
María Benito Sánchez
Keyword(s):  
Soft Tissue ◽  
Late Stage ◽  
Good Condition ◽  
Experimental Studies ◽  
The Body ◽  
Health Law ◽  
External Appearance ◽  
Intrinsic Factors ◽  
Preservation Technique ◽  
Extrinsic And Intrinsic Factors

Decomposition is a natural process that begins approximately four minutes after death and continues until the body is degraded to simpler biochemical components which are gradually recycled back to the environment. This process is dependent on extrinsic and intrinsic factors. Embalming is a chemical preservation technique that aims to preserve the external appearance of the body in good condition for an indeterminate period. In Spain, there is a lack of experimental studies carried out to analyse the variables that affect decomposition in embalmed bodies, therefore, in accordance with the conclusions reached by previous authors, it is hypothesised that embalmed bodies show quantifiable characteristics during the late stage decomposition which distinguish them from control, unembalmed, cadavers. An anthropological and statistical analysis was performed on 14 individuals from Cementerio Sur de Madrid exhumed after ten years according to the Mortuary Health Law of the Autonomous Region of Madrid. The preliminary results obtained showed that there is a qualitative and statistically significant relationship between the variables evaluated, being the presence or absence of soft tissue the most notable difference. The mortuary or thanatopraxy treatments performed before the burial and the microenvironmental conditions of the burial positively influence the soft tissue preservation on embalmed bodies. These results contribute to the understanding about the decomposition rate of an embalmed cadavers in cemeteries, and the related extrinsic variables.

EVALUATION OF TOXIOLOGICAL INDICATORS OF MONTHMORRILLONITE CLAY FOR THE PURPOSE OF USING THEM AS ALUMOSILICATE SOBENT AGAINST THE NEGATIVE EFFECT OF MYCOTOXINS ON THE BODY OF ANIMALS AND BIRDS

2021 ◽  
Vol 1 (1) ◽  
pp. 72-78
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
Montmorillonite Clay ◽  
Test Substance ◽  
Negative Effects ◽  
Experimental Animals ◽  
Eyelid Edema ◽  
White Rats ◽  
Mucous Membranes ◽  
Negative Effect

The article presents the results of laboratory studies to assess the toxicological parameters of montmorillonite clay from the Pogadaevskoye deposit in the West Kazakhstan region in order to use them as an aluminosilicate sorbent in the composition of feeds that reduce the negative effects of mycotoxins on the body of animals and birds. The relevance of research is associated with the cultivation of healthy and highly productive animals and poultry in order to ensure the food security of the Republic of Kazakhstan.The studies carried out to assess the toxicological parameters of montmorillonite clay in order to use them as an aluminosilicate sorbent in experimental animals (rabbits and white rats) allowed the following results to be obtained: Visual study of the intensity of erythema when exposed to the test substance on the skin of rabbits showed their absence (0 points). The study of the intensity of edema (an increase in the thickness of the skin clutch of rabbits) when exposed to the test substance on the skin of rabbits showed no reaction (0 points). Studies evaluating the irritating effect of the test substances on the mucous membranes of the eyes of rabbits by symptoms of damage showed the absence of hyperemia (0 points). Weak eyelid edema (1 point), the minimum amount of discharge in the corner of the eye (1 point). The results of studies on the classification assessment of the test substance for the severity of the irritant effect on the eyes of rabbits showed that the average total score of the severity of the irritative effect corresponds to 1 point. A comprehensive analysis of the results obtained on the basis of scientific and experimental studies to assess the toxicological indicators of montmorillonite clay from the Pogadaevskoye deposit in relation to irritating effects on the skin and mucous membranes of experimental animals (rabbits) showed their harmlessness.

STATE OF AUTONOMIC REGULATION OF HEART RHYTHM IN YOUNG AND AGED RATS BEFORE AND AFTER APPLICATION OF DIFFERENT REGIMENS OF RHYTHMIC EXTREME COOLING

2020 ◽  
pp. 436-443
Author(s):  
В. В. Кулик ◽  
В. Г. Бабийчук
Keyword(s):  
Heart Rate ◽  
Metabolic Regulation ◽  
Experimental Studies ◽  
Autonomic Regulation ◽  
The Body ◽  
Total Power ◽  
Aged Rats ◽  
Cooling Mode ◽  
Adaptive Capabilities ◽  
Extreme Cold

В работе изучено влияние разных режимов ритмических экстремальных холодовых воздействий на состояние вегетативной регуляции сердечного ритма у молодых и старых крыс. По данным спектрального анализа вариабельности сердечного ритма установлено, что у молодых крыс использование температурных режимов ритмических экстремальных холодовых воздействий, РЭХВ (-120 °С; -120 °С; -120 °С) и (-60 °С; -120 °С; -120 °С) значительно повышало адаптационные возможности организма за счет активации собственных гомеостатических регуляторных систем. При этом комбинированный режим РЭХВ (-60 °С; -120 °С; -120 °С) оказался наиболее оптимальным для старых животных, поскольку его применение не сопровождалось чрезмерной активацией симпатико-адреналовой системы на ранних этапах экспериментальных исследований в отличие от режима (-120 °С; -120 °С; -120 °С). Кроме того, использование данного режима охлаждения способствовало статистически значимому увеличению показателей общей мощности спектра нейрогуморальной регуляции не столько за счет повышения активности гуморально-метаболического звена регуляции, преобладание которого характерно для пожилого возраста, сколько благодаря увеличению тонуса вегетативных центров, причем парасимпатические влияния на миокард превалировали над симпатическими. The influence of various rhythmic extreme cold effects on the state of autonomic regulation of heart rate in young and aged rats was studied. According to the spectral analysis of heart rate variability, it has been found that in young rats, using rhythmic extreme cold exposures (RECE) temperature regimens of (-120 °С; -120 °С; -120 °С) and (-60 °С; -120 °С; -120 °С) significantly increased adaptive capabilities of the body due to the activation of its own homeostatic regulatory systems. At the same time, the combined regimen of RECE (-60 °С; -120 °С; -120 °С) occurred to be the most optimal for aged animals, since its use was not accompanied with an excessive activation of sympathoadrenal system at the early stages of experimental studies, in contrast to the regimen (-120 °С; -120 °С; -120 °С). In addition, the use of this cooling mode contributed to a statistically significant increase in the total power of spectrum of neurohumoral regulation not so much due to a rise in activity of humoral-metabolic regulation link, the prevalence of which is characteristic of an old age, but due to an increase in the tone of vegetative centers, herewith the parasympathetic effects on the myocardium prevailed sympathetic ones.

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