scholarly journals III. DECREASE OF LABELED DNA IN CELLS OF THE ADRENAL MEDULLA AFTER INTERMITTENT EXPOSURE TO COLD

1969 ◽  
Vol 42 (2) ◽  
pp. 460-468 ◽  
Author(s):  
S. R. Pelc ◽  
Maria Pia Viola-Magni
Keyword(s):  
Dna Synthesis ◽  
Mitotic Index ◽  
Adrenal Medulla ◽  
Room Temperature ◽  
Statistical Evaluation ◽  
Cold Treatment ◽  
Labeling Index ◽  
Initial Value ◽  
Exposure To Cold ◽  
Intermittent Exposure

Italico rats were injected with thymidine-3H 6 hr after the end of 300 hr of intermittent cold treatment. This plan of experiment ensured replacement in the adrenal medulla of lost DNA which is specifically sensitive to cold treatment and has a labeling index sufficiently high for statistical evaluation. The labeling index in the adrenal medulla decreases to one-half of the initial value within 10 days in animals subjected to further intermittent cold treatment and within 32 days in animals kept at room temperature. The very low mitotic index and the absence of doubling of the labeling index show that the observed labeling cannot be ascribed to pre-mitotic DNA synthesis. The concept of metabolic DNA adequately explains the findings.

scholarly journals A RADIOAUTOGRAPHIC STUDY WITH H3-THYMIDINE ON ADRENAL MEDULLA NUCLEI OF RATS INTERMITTENTLY EXPOSED TO COLD

1966 ◽  
Vol 28 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Maria Pia Viola-Magni
Keyword(s):  
Cell Division ◽  
Dna Synthesis ◽  
Adrenal Medulla ◽  
Cold Exposure ◽  
Dna Content ◽  
Room Temperature ◽  
Marked Variation ◽  
Considerable Decrease ◽  
The Third

A considerable decrease (24 to 40%) of DNA content per nucleus previously observed in the adrenal medulla of rats exposed intermittently to cold is followed by restoration to normal and supranormal values. This phenomenon has now been studied by use of H3-thymidine, which was given to normal rats, to rats exposed to cold, and to animals brought to room temperature after cold exposure. In the first two conditions, no significant labeling of nuclei was observed. In the third, labeling took place clearly in the 1st 3 days. The grain counts showed that the early labeled nuclei had more grains than those labeled later, indicating differences in the rate of DNA synthesis. A statistically significant correlation was found, on the same nuclei, between amount of Feulgen dye and number of grains. It is concluded that net synthesis of DNA takes place in the phase of recovery from cold. This fact is not related to cell division, as no mitoses could ever be detected, but rather to the cold-induced loss of DNA. Clear demonstration is thus given of a marked variation in the amount of DNA per nucleus in relation to the functional conditions of adrenal medulla cells.

scholarly journals AN ANALYSIS OF DNA LOSS AND SYNTHESIS IN THE RAT ADRENAL MEDULLA NUCLEI UPON COLD STIMULATION

1966 ◽  
Vol 30 (2) ◽  
pp. 213-225 ◽  
Author(s):  
Maria Pia Viola-Magni
Keyword(s):  
Dna Synthesis ◽  
Adrenal Medulla ◽  
Cold Exposure ◽  
Dna Content ◽  
Room Temperature ◽  
Rapid Change ◽  
Cumulative Exposure ◽  
Cell Nuclei ◽  
Cold Stimulation ◽  
Dna Loss

The peculiar changes previously observed in DNA content of rat adrenal medulla cell nuclei upon intermittent cold exposure (15 hr at +4°C followed by 9 hr at room temperature) have been further studied with the aid of Feulgen histophotometry and H3-thymidine radioautography. The amount of DNA decreases progressively with increasing length of cold exposure until 300 hr (-32%). Later a rapid change takes place, whereby DNA content per nucleus returns to values which are slightly, but consistently lower than normal. At termination of a period of cumulative exposure to cold, an analysis of a whole-day experimental cycle shows that the DNA decrease is due to loss of DNA during cold exposure and that DNA synthesis occurs upon return to room temperature. The balance between these two processes can be divided into three stages: (a) loss of DNA up to 300 hr of cumulative cold exposure; (b) marked increase in DNA by 350 hr; (c) oscillation around zero or slightly negative at 400 hr and beyond. These variations are due to: (1) the extension of DNA synthesis into the period of cold exposure as clearly demonstrated by radioautography (stage b), and (2) a later still greater DNA loss (stage c) which partly offsets the increased synthesis. A complex pattern of adaptation of the adrenal medulla cells, as regards DNA content, to the repetitive cold stimulus is thus demonstrated.

scholarly journals II. DIFFERENCES IN ADRENAL MEDULLA NUCLEAR DNA CONTENT AMONG RATS OF DIFFERENT STRAINS FOLLOWING INTERMITTENT EXPOSURE TO COLD

1969 ◽  
Vol 42 (2) ◽  
pp. 452-459 ◽  
Author(s):  
Roberto Tongiani ◽  
Maria Pia Viola-Magni
Keyword(s):  
Adrenal Medulla ◽  
Wistar Rats ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Sprague Dawley ◽  
Exposure To Cold ◽  
Intermittent Exposure ◽  
Dna Loss ◽  
Long Evans ◽  
Different Strains

The amount of DNA per nucleus in the adrenal medulla cells of four different strains of rats (Wistar, Sprague-Dawley, Long-Evans, and Italico) is determined both under control conditions and after 300 hr of intermittent exposure to cold. The adrenal medulla nuclei of the four strains of rats contain the same amount of DNA; however, the loss of DNA observed after the same experimental treatment differs markedly in the different strains. The loss is small in Wistar and Sprague-Dawley rats (8–13%), larger in Long-Evans rats (20%) and still larger in Italico rats (45%). The DNA loss in Wistar rats increases if the animals are fed the same diet as the Italico rats, and the DNA loss in Italico rats is reduced if the animals are fed the same diet as the Wistar rats. The different behavior of the four strains is discussed in terms of turnover of DNA.

Mitotic Index and Ki-67 Nuclear Antigen Labeling Index as Predictors of Chemotherapy Response in Uterine Cervical Carcinoma

2001 ◽  
Vol 83 (3) ◽  
pp. 555-559 ◽  
Author(s):  
Seiryu Kamoi ◽  
Yoshiharu Ohaki ◽  
Susumu Okada ◽  
Norihiro Matsushita ◽  
Takashi Kawamura ◽  
...  
Keyword(s):  
Mitotic Index ◽  
Cervical Carcinoma ◽  
Labeling Index ◽  
Nuclear Antigen ◽  
Chemotherapy Response ◽  
Ki 67 ◽  
Uterine Cervical Carcinoma

Heat Transfer Analysis of Room-Temperature Finned-Tube Evaporator for Cryogenic Nitrogen

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Shun Ching Lee ◽  
Tzu-Min Chen
Keyword(s):  
Heat Flux ◽  
Room Temperature ◽  
Integrated Model ◽  
Finned Tube ◽  
Heat Transfer Analysis ◽  
Outlet Temperature ◽  
Ambient Conditions ◽  
Governing Equations ◽  
Initial Value ◽  
Two Phase

Abstract The behavior of cryogenic nitrogen in a room-temperature evaporator six meters long is analyzed. Trapezoid fins are employed to enhance the heat flux supplied by the environment. The steady-state governing equations specified by the mixed parameters are derived from the conservations of momentum and energy. The initial value problem is solved by space integration. The fixed ambient conditions are confirmed by way of the meltback effect. An integrated model is utilized to analyze the convective effect of two-phase flow, which dominates the evaporation behavior. Another integrated model is employed to determine the total heat flux from the environment to the wet surface of the evaporator. The foundation of the formation of an ice layer surrounding the evaporator is presented. If the fin height is shorter than 0.5 m, the whole evaporator is surrounded by ice layer. If the fin height is longer than 0.5 m, the total pressure drop of nitrogen in the tube is negligible. The outlet temperature is always within the range between −12 °C and 16 °C for the evaporator with the fin height of 1.0 m. For the evaporator with dry surface, the nitrogen has the outlet temperature less than the ambient temperature at least by 5 °C.

scholarly journals Purification of a liver DNA-synthesis promoter from plasma of partially hepatectomized rats

1986 ◽  
Vol 235 (1) ◽  
pp. 49-55 ◽  
Author(s):  
J J Díaz-Gil ◽  
P Escartín ◽  
R García-Cañero ◽  
C Trilla ◽  
J J Veloso ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Mitotic Index ◽  
Gel Electrophoresis ◽  
Deae Cellulose ◽  
Single Band ◽  
Organ Specificity ◽  
Purification Procedure

A protein was isolated from plasma of partially (70%) hepatectomized rats that, injected in mice, increases the uptake of [3H]thymidine by liver DNA by 200-300% over that by injected control saline. The purification procedure consists essentially of three chromatography steps, employing Sephadex G-75, DEAE-cellulose and hydroxyapatite. The hepatic promoter (HP) preparation shows a single band in SDS/polyacrylamide (15%)-gel electrophoresis (silver stained), with an Mr of 64 000; its activity is suppressed by trypsin or pepsin and is unaffected by deoxyribonuclease or ribonuclease. On injection into mice (150 ng/mouse), it increases the mitotic index of the liver. It shows organ-specificity, acting on liver but not on spleen, kidney, lung or brain. In primary liver cultures, it produces an increase in uptake of [3H]thymidine into DNA in the range 1-10 ng/ml. In this system in vitro, it increases the uptake of 22Na+ immediately after addition.

Study on Schottky Diode Characteristics Improving by X-Ray Irradiation

2013 ◽  
Vol 717 ◽  
pp. 113-116
Author(s):  
Sani Klinsanit ◽  
Itsara Srithanachai ◽  
Surada Ueamanapong ◽  
Sunya Khunkhao ◽  
Budsara Nararug ◽  
...  
Keyword(s):  
Leakage Current ◽  
Schottky Diode ◽  
Room Temperature ◽  
The Other ◽  
Low Power Consumption ◽  
Initial Value ◽  
X Ray ◽  
Forward Current ◽  
Current Voltage ◽  
Current Voltage Characteristics

The effect of soft X-ray irradiation to the Schottky diode properties was analyzed in this paper. The built-in voltage, leakage current, and work function of Schottky diode were investigated. The current-voltage characteristics of the Schottky diode are measured at room temperature. After irradiation at 70 keV for 55 seconds the forward current and leakage current are increase slightly. On the other hand, the built-in voltage is decrease from the initial value about 0.12 V. Consequently, this method can cause the Schottky diode has low power consumption. The results show that soft X-ray can improve the characteristics of Schottky diode.

scholarly journals Induction of pancreatic acinar cell proliferation by thyroid hormone

2005 ◽  
Vol 185 (3) ◽  
pp. 393-399 ◽  
Author(s):  
G M Ledda-Columbano ◽  
A Perra ◽  
M Pibiri ◽  
F Molotzu ◽  
A Columbano
Keyword(s):  
Cell Proliferation ◽  
Thyroid Hormone ◽  
Dna Synthesis ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Labeling Index ◽  
Metabolic Effects ◽  
Brdu Incorporation ◽  
Pancreatic Cell

Thyroid hormone is known to elicit diverse cellular and metabolic effects in various organs, including mitogenesis in the rat liver. In the present study, experiments were carried out to determine whether thyroid hormone is able to stimulate cell proliferation in another quiescent organ such as the pancreas. 3,5,3′-l-tri-iodothyronine (T3) added to the diet at a concentration of 4 mg/kg caused a striking increase in nuclear bromodeoxyuridine (BrdU) incorporation of rat acinar cells 7 days after treatment (the labeling index was 46.7% in T3-treated rats vs 7.1% in controls). BrdU incorporation was limited to the acinar cells, with duct cells and islet cells being essentially negative. The increase in DNA synthesis was accompanied by the presence of several mitotic figures. Histological examination of the pancreas did not exhibit any sign of T3-induced toxicity. Determination of the apoptotic index, measurement of the serum levels of α-amylase and lipase, and glycemia determination did not show any increase over control values, suggesting that the enhanced proliferation of acinar cells was a direct effect induced by T3 and not a regenerative response consequent to acinar or β-cell injury. Additional experiments showed that DNA synthesis was induced as early as 2 days after T3 treatment (the labeling index was 9.4 vs 1.9% in controls) and was associated with increased protein levels of cyclin D1, cyclin A and proliferating cell nuclear antigen, with no substantial differences in the expression of the cyclin-dependent kinase inhibitor p27. The mitogenic effect of T3 on the pancreas was not limited to the rat, since extensive acinar cell proliferation was also observed in the pancreas of mice treated with T3 for 1 week (the labeling index was 28% in T3-treated mice vs 1.8% in controls). Treatment with three other ligands of nuclear receptors, ciprofibrate, all-trans retinoic acid and 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene, induced little or no pancreatic cell proliferation. These results demonstrated that T3 is a powerful inducer of cell proliferation in the pancreas and suggested that pancreatic acinar cell proliferation by selected agents may have potential for therapeutic use.

Neurotrophic control of events in injured forelimbs of larval urodeles

Development ◽  
1982 ◽  
Vol 69 (1) ◽  
pp. 183-192
Author(s):  
Anthony L. Mescher
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Mitotic Activity ◽  
Mitotic Index ◽  
Elevated Level ◽  
Labelling Index ◽  
Neurotrophic Control ◽  
Epimorphic Regeneration ◽  
Baseline Levels

Denervated forelimbs and contralateral innervated forelimbs of Ambystoma larvae were injured internally distal to the elbow by compression with watchmaker's forceps. Innervated controls completely repaired the crush injury within one week; denervated limbs failed to repair the injury and exhibited varying degrees of limb regression. Histological examination revealed that the process of tissue dedifferentiation initiated by injury was more extensive in denervated, regressing limbs than in controls. In innervated limbs, both the DNA labelling index and the mitotic index peaked approximately 4–6 days after the injury and returned to baseline levels by 10 days. In denervated limbs, the DNA labelling index also increased and remained at an elevated level for at least 2 weeks after the injury, but significant mitotic activity was not observed. The data indicate that intact nerves are not needed for cellular dedifferentiation, cell cycle re-entry, and DNA synthesis in injured limbs, but are required for the cells to proliferate and repair the injury. These results are discussed together with those of similar experiments on the role of nerves during the initiation of epimorphic regeneration in amputated limbs.

Reversibility of endocrine changes produced in guinea pigs by exposure to cold

1965 ◽  
Vol 208 (1) ◽  
pp. 115-117 ◽  
Author(s):  
Harry Sobel ◽  
George C. Haberfelde ◽  
Albert E. Reeves
Keyword(s):  
Glucose Tolerance ◽  
Guinea Pigs ◽  
Room Temperature ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Definite Evidence ◽  
Exposure To Cold ◽  
Thyroid Glands ◽  
Oral Glucose Tolerance Tests ◽  
Glucose Tolerance Tests

Guinea pigs were exposed continuously to a temperature of 2–4 C for 6 months. They were then reacclimatized to room temperature, and after 4–6 months certain tests were carried out. During control collections and following exposure to cold the previously cold-exposed animals exhibited urinary corticoid excretion values which were approximately 10% below those of their controls. Following intraperitoneal injection of ACTH the response was approximately 20% greater. However, these differences were not statistically significant. Oral glucose tolerance tests revealed definite evidence of reduction in tolerance in the previously cold-exposed animals. Six animals exhibited 150-min values which exceeded by more than 20 mg/ 100 ml the highest value observed in the controls. Fourteen others whose values fell within this limit exhibited a statistically significant increase in the 150-min value as compared with the controls. The PBI values were the same in each group. There were no histological residues in the pituitary, adrenal, pancreas, and thyroid glands.

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