Age and Mitotic Activity in the Male Mouse, Mus Musculus L

1949 ◽  
Vol 26 (3) ◽  
pp. 261-286
Author(s):  
W. S. BULLOUGH
Keyword(s):  
Mitotic Activity ◽  
Diurnal Cycle ◽  
Male Mouse ◽  
Middle Age ◽  
Sugar Content ◽  
Rest Period ◽  
Point Of View ◽  
Bodily Activity ◽  
Vital Factor ◽  
Mitosis Rate

1. A study has been made of the mitosis rate and of the diurnal cycles of male mice during each of the first 20 months of life. The mice used belonged to the Kreyberg's white label and the Strong's CBA strains. Most of the observations were made on the ear epidermis, but some attention was also given to other tissues. 2. It was discovered that, when judged from the point of view of mitotic activity, the life of a male mouse consists of four ages. During the immature age the animals are still growing and their mitosis rate is generally high, although the ear epidermis provides an exception to this rule. During the mature age which lasts from about the 3rd to the 12th month the mitosis rate is lowered. During the middle age which follows the mitosis rate increases, but in senility it is again reduced. 3. Coincident with these changes in the mitosis rate are changes in the spontaneous bodily activity. The mice are most active during immaturity and maturity. In middle age their activity is reduced by about half, and in senility they spend almost the whole time resting. Particularly in the Strong's CBA mice there are also changes in the timing of the diurnal cycle of spontaneous bodily activity, and these are immediately mirrored by changes in the timing of the diurnal cycle of mitotic activity so that throughout life a general inverse relationship between bodily activity and mitotic activity is maintained. 4. In middle-aged Strong's CBA males the daily rest period extends almost without interruption from 06.00 to 18.00 hr. However, the most active cell division develops only at the beginning of this period, and it is evident that in prolonged sleep a lack of some vital factor develops. It is shown that subcutaneous injections of starch overcome this lack in sleeping mice and result almost immediately in the redevelopment of a high mitosis rate. Thus it would appear that sugar is the vital factor involved, and that the sugar content of the tissues is quickly used up during high mitotic activity. 5. These results are discussed particularly in relation to the problem of carcinogenesis.

scholarly journals The effects of experimentally induced rest and exercise on the epidermal mitotic activity of the adult male mouse, Mus musculus L

1948 ◽  
Vol 135 (879) ◽  
pp. 233-242 ◽  
Keyword(s):  
Mitotic Activity ◽  
Adult Male ◽  
Male Mouse ◽  
Time Of Day ◽  
Excessive Exercise ◽  
Adult Male Mouse ◽  
Preliminary Study ◽  
High Level ◽  
Mitosis Rate ◽  
Rest And Exercise

As a preliminary study of the conditions which affect the hour to hour variations in epidermal mitotic activity in the adult male mouse, experiments were carried out involving artificially induced sleep and exercise. In the first experiment the animals were injected with a dose of barbiturates sufficient to induce sleep for a period of 3 or 4 hr. at a time of day when they were usually active. The injections were given at 17.00 hr. as the animals were waking from their afternoon sleep, and they resulted in a sharp rise in mitotic activity. A maximum was reached at 20.00 hr., the time when the mitotic activity of the controls had dropped to a minimum. As the animals recovered and became active, their mitosis rate fell quickly to a low level. In the second experiment the animals were placed in a slowly revolving box, and so forced to remain awake and active throughout an afternoon when they would otherwise have been asleep. This treatment resulted in extremely low mitotic activity, in contrast to which that of the normally sleeping controls rose to a high level. It is probably significant that when the mice were released from the revolving box, and could at last sleep, their mitosis rate remained low. This suggests that the excessive exercise had either resulted in the production of some mitosis-depressing substance which remained in the system, or that some substance vital to mitosis had been used up and took some time to be replaced. The conclusion is now justified that the rate of epidermal mitosis normally increases during sleep, and decreases during hours of wakefulness and exercise. In this way the form of the diurnal mitosis cycle is determined by the habits of the animals.

scholarly journals Mitotic activity in the adult male mouse, Mus musculus L. The diurnal cycles and their relation to waking and sleeping

1948 ◽  
Vol 135 (879) ◽  
pp. 212-233 ◽  
Keyword(s):  
Cell Division ◽  
Mitotic Activity ◽  
Adult Male ◽  
Individual Variation ◽  
Male Mouse ◽  
Duodenal Mucosa ◽  
Seminiferous Tubules ◽  
Diurnal Cycles ◽  
Adult Male Mouse ◽  
Bodily Activity

The diurnal cycles of mitotic activity in the ear epidermis of the adult male mouse have been determined by the removal of earclips at 2 hr. intervals throughout the 24 hr. The mice used were between 3 and 4 months old, and were of the Kreyberg white label and Strong’s CBA strains. A considerable degree of individual variation was found, but on the average the maximum mitotic activity was at 06.00 and 14.00 hr. and the minimum mitotic activity at 10.00 and 20.00 hr. This observation was confirmed by killing groups of mice, each group consisting of five males, at the same 2 hr. intervals throughout the 24 hr. Similar variations in the mitotic activity of the ear epidermis were observed, and, in addition, similar cycles were evident in the mid-dorsal epidermis of the back, the stratified epithelium of the oesophagus, the lining epithelium of the epididymis, and the proliferating zone of the duodenal mucosa. In this last tissue the rate of cell division never fell to a very low figure, and in the proliferating centres of the intestinal lymph nodules and in the seminiferous tubules of the testis there was no trace of a cycle since the rate of cell division remained constantly high. A study was also made of the spontaneous bodily activity of the mice throughout the 24 hr., and by comparing the average figures so obtained with the average figures for epidermal mitosis, it proved possible to make the significant correlation that when the animals are at rest mitotic activity is at a maximum and that when they are awake and active it is at a minimum. This correlation permits an explanation of the individual variation in mitotic activity, since there is also a high degree of individual variation in spontaneous bodily activity. It also permits an explanation of the contradictory results which have been reported in the past regarding diurnal mitosis rhythms in mice, since it is evident that the rhythms of bodily activity must be strongly affected by differences in the age, sex and condition of the animals used, in the season of the year, and in the routine of the laboratory.

The Relation Between the Epidermal Mitotic Activity and the Blood-Sugar Level in the Adult Male Mouse, Mus Musculus L

1949 ◽  
Vol 26 (1) ◽  
pp. 83-99
Author(s):  
W. S. BULLOUGH
Keyword(s):  
Mitotic Activity ◽  
Blood Sugar ◽  
Adult Male ◽  
Male Mouse ◽  
Blood Sugar Level ◽  
Normal Animal ◽  
Critical Factor ◽  
Diurnal Changes ◽  
Adult Male Mouse ◽  
Mitosis Rate

1. An investigation has been made of the relation between the concentration of the blood sugar and the mitotic activity of the ear epidermis of the adult male mouse. It has been shown that, within limits, an increase in the blood-sugar level, induced by subcutaneous injections of starch, results in an increased mitosis rate. Conversely, a decrease in the blood-sugar level, induced by insulin, causes a decreased mitosis rate. A deep mitosis depression is also caused by injections of phloridzin. 2. Since it is known that phloridzin interferes with the phosphorylation of sugar, and since it is also shown that injections of phosphate augment the effect produced by starch alone, the tentative suggestion is put forward that sugar may act by satisfying the energy requirements of mitosis. 3. However, in the normal animal the diurnal changes in the blood-sugar level are the inverse of the diurnal changes in mitotic activity, the concentration of the blood sugar being relatively low during sleep when the mitosis rate is relatively high. It is therefore evident that, within normal limits, the level of the blood sugar as such is not an important factor in the control of the diurnal mitosis cycles. 4. It is considered probable that the critical factor in the control of these cycles is the concentration of sugar, or glycogen, within the tissues themselves. Thus during sleep, sugar is probably deposited in the tissues, as it is known to be in the liver, so accounting simultaneously for the fall in the level of the blood sugar and the rise in the mitosis rate.

scholarly journals The “Zero Miles Product” Concept Applied to Biofuel Production: A Case Study

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 565
Author(s):  
Nikolaj Kaae Kirk ◽  
Clara Navarrete ◽  
Jakob Ellegaard Juhl ◽  
José Luis Martínez ◽  
Alessandra Procentese
Keyword(s):  
Sugar Content ◽  
Point Of View ◽  
Biofuel Production ◽  
Transport Costs ◽  
Economic Point ◽  
Product Concept ◽  
Energy Demands ◽  
Production Platform ◽  
High Sugar Content

To make biofuel production feasible from an economic point of view, several studies have investigated the main associated bottlenecks of the whole production process through approaches such as the “cradle to grave” approach or the Life Cycle Assessment (LCA) analysis, being the main constrains the feedstock collection and transport. Whilst several feedstocks are interesting because of their high sugar content, very few of them are available all year around and moreover do not require high transportation’ costs. This work aims to investigate if the “zero miles” concept could bring advantages to biofuel production by decreasing all the associated transport costs on a locally established production platform. In particular, a specific case study applied to the Technical University of Denmark (DTU) campus is used as example to investigate the advantages and feasibility of using the spent coffee grounds generated at the main cafeteria for the production of bioethanol on site, which can be subsequently used to (partially) cover the campus’ energy demands.

scholarly journals Occurrence of Furosine and Hydroxymethylfurfural in Breakfast Cereals. Evolution of the Spanish Market from 2006 to 2018

Foods ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 158 ◽  
Author(s):  
Marta Mesías ◽  
Laura Sáez-Escudero ◽  
Francisco J. Morales ◽  
Cristina Delgado-Andrade
Keyword(s):  
Manufacturing Process ◽  
Protein Quality ◽  
Sugar Content ◽  
Point Of View ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Breakfast Cereal ◽  
Breakfast Cereals ◽  
Damage Indices ◽  
Amadori Compounds

The demand for healthier products has led the breakfast cereal sector to develop new formulations to improve the nutritional profile of breakfast cereals; however, the increase in chemical risks should also be evaluated. Amadori compounds and 5-hydroxymethylfurfural (HMF) are Maillard reaction products applied as heat damage indices in breakfast cereals. Furosine (a synthetic amino acid formed by acid hydrolysis of Amadori compounds) is linked to the loss of protein quality, while HMF has exhibited toxicological effects in cells and animals. Furosine and HMF content was evaluated in Spanish breakfast cereals whereas the effect of protein, fibre, and sugar content, the type of grain, the presence of honey, and the manufacturing process were discussed, as well as compared with a previous prospective study. The average furosine and HMF contents were 182 mg/kg and 21.7 mg/kg, respectively. Protein and fibre content were directly related to the furosine content, whereas sugar level, honey addition, and the manufacturing process affected the content of HMF. Occurrence of furosine and HMF decreased nearly 40% in a decade (2006–2018). These findings are relevant in terms of nutritional score, since lysine availability is preserved, but also from a toxicological point of view, due to the decreased daily exposure to both compounds, which dropped 30%.

Sulphur and phosphorus transformations in wastewater storage and treatment reservoirs in northeast Brazil

2000 ◽  
Vol 42 (10-11) ◽  
pp. 203-210 ◽  
Author(s):  
A. L. Araújo ◽  
R. de Oliveira ◽  
D. D. Mara ◽  
H. W. Pearson ◽  
S. A. Silva
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Removal ◽  
Rest Period ◽  
Pilot Scale ◽  
Point Of View ◽  
Faecal Coliform ◽  
Northeast Brazil ◽  
Organic Loading ◽  
Biological Toxicity ◽  
Who Guideline

Sulphur and phosphorous transformations were studied in two pilot-scale wastewater storage and treatment reservoirs on the basis of four experiments carried out at EXTRABES in northeast Brazil. The reservoirs were fed with the effluent from an anaerobic pond and after filling they were allowed to rest until faecal coliform numbers dropped below 100 cfu/100 ml (10 times below the WHO guideline for unrestricted irrigation). During the filling periods sulphate was reduced to sulphide which reached high values by the beginning of the rest period, decreasing thereafter due to its oxidation, mainly to sulphate. Based on these results a rest period of at least two months is required for sulphide to fall to safe levels from the point of view of biological toxicity. Total phosphorus removal in the reservoirs was low, 9–33%; soluble orthophosphate concentrations remained virtually unchanged, especially when the initial organic loading was high.

scholarly journals Los grupos consonánticos /-n’r-/ y /-l’r-/ en el futuro : simple y en el condicional simple del castellano

2009 ◽  
Vol 14 ◽  
pp. 89-98
Author(s):  
Mónika Kispéter
Keyword(s):  
Middle Age ◽  
Syllable Structure ◽  
Point Of View ◽  
Spanish Speakers ◽  
The Other ◽  
Future Tense ◽  
Conditional Mode ◽  
Verb Forms ◽  
Los Grupos

The aim of this article is the investigation of certain Spanish conjugated verb forms in future tense and in conditional mode. These forms during the Middle Age had more verb stems; as opposed to this, in Modern Spanish only one of these stems is found. These forms are the result of the medieval Spanish speakers’ intent to avoid the “inconvenient” secondary consonantal groups /-n’r-/ and /-l’r-/ that had emerged as the consequence of syncope. Four different verb stems were e. g. in the case of the verb venir: (1) there is no change, so the secondary consonantal group is not dissolved (venré); (2) assimilation occurred, the /n/ assimilated to the /r/ (verré); (3) metathesis was produced, which means that the two sounds (verné); (4) there is an epenthesis, between the /n/ or the /l/ and the /r/ inserts a phoneme (vendré). The former case is the sonly applied one in Modern Spanish. The article attempts to explain why only this one form is used in the case of the verbs, although there are examples of the other phenomena in other Modern Spanish words. The article also gives explanation of the formation of these words. Furthermore, all four verb stems are examined from the point of view of its syllable structure, the universal sonority hierarchy ad morphology.

The Diurnal Variations in the Tissue Glycogen Content and Their Relation to Mitotic Activity in the Adult Male Mouse

1950 ◽  
Vol 27 (3) ◽  
pp. 257-263
Author(s):  
W. S. BULLOUGH ◽  
E. A. EISA
Keyword(s):  
Mitotic Activity ◽  
Adult Male ◽  
Adult Mouse ◽  
Glycogen Content ◽  
Rate Increase ◽  
Liver Glycogen ◽  
Diurnal Variations ◽  
Male Mice ◽  
Liver Glycogen Content ◽  
Mitosis Rate

1. A description is given of the hour-to-hour variation in the liver glycogen content in adult male mice, and it is shown that the concentration is highest while the animals are asleep and lowest while they are awake. 2. A similar cycle is also described in the glycogen content of the skin. Histologically it is shown that a high proportion of the skin glycogen lies in the cytoplasm of the epidermal cells, and that during sleep both the epidermal glycogen content and the epidermal mitotis rate increase considerably. The skin glycogen content and the epidermal mitotic activity also show a marked increase after a subcutaneous injection of 20 mg. starch, while they are both abnormally depressed after two injections of 1/50 unit insulin. 3. These results, together with others previously reported, are in agreement with the theory that at the onset of sleep glucose is deposited from the blood into the tissues where it appears in the form of glycogen. Since it is known that glucose, or glycogen, is a critical substance affecting mitotic activity in the adult mouse, it is logical to find that an increase in the epidermal glycogen content is accompanied by a greatly increased mitosis rate. On waking, the reverse process takes place, glycogen being withdrawn as glucose into the blood and mitotic activity falling to a low level.

Regeneration and pattern formation in planarians

Development ◽  
1984 ◽  
Vol 83 (1) ◽  
pp. 63-80
Author(s):  
Emili Saló ◽  
Jaume Baguñà
Keyword(s):  
Pattern Formation ◽  
Mitotic Activity ◽  
Intermediate Stage ◽  
Point Of View ◽  
Blastema Formation ◽  
Biphasic Pattern ◽  
Spatial Point ◽  
Planarian Regeneration ◽  
Undifferentiated Cells ◽  
S Period

Mitotic activity during regeneration in the planarian Dugesia (G) tigrina shows a biphasic pattern, with a first maximum at 4–12 h, a second and higher maximum at 2–4 days, and a relative minimum in between. The first peak is mainly due to pre-existing G2 cells entering mitosis shortly after cutting, whereas the second maximum is due to cells that divide after going through the S period from the onset of regeneration. From a spatial point of view, the highest mitotic values are found in stump (postblastema) regions near the wound (0–300 µm), though regions far from it also show increased mitotic values but always lower overall values. As regeneration continues the postblastema maximum shifts slightly to more proximal regions. In contrast, no mitosis has been found within the blastema, even though the number of blastema cells increases steadily during regeneration. These results suggest that blastema in planarians forms through an early accumulation of undifferentiated cells at the wound boundary, and grows by the continuous local migration of new undifferentiated cells from the stump to the base of blastema. The results obtained demonstrate that blastema formation in planarians occurs through mechanisms somewhat different to those shown to occur in the classical epimorphic models of regeneration (Annelida, Insecta, Amphibia), and suggest that planarian regeneration could represent an intermediate stage between morphallactic and epimorphic modalities of regeneration.

A Diurnal Cycle in the Mitotic Activity of Ascites Tumour Cells in Mice

Nature ◽  
1957 ◽  
Vol 180 (4588) ◽  
pp. 705-706 ◽  
Author(s):  
I. P. S. AGRELL ◽  
ELSA WELIN-BERGER
Keyword(s):  
Mitotic Activity ◽  
Diurnal Cycle ◽  
Tumour Cells ◽  
Ascites Tumour ◽  
Ascites Tumour Cells
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