scholarly journals Rat leukocyte population dynamics predicts a window for intervention in aging.

2022 ◽  
Author(s):  
Isabel Beerman ◽  
Hagai Yanai ◽  
Christopher Dunn ◽  
Bongsoo Park ◽  
Christopher Coletta ◽  
...  
Keyword(s):  
Blood Parameters ◽  
Model System ◽  
Chronological Age ◽  
Aging Effects ◽  
Age Changes ◽  
Leverage Points ◽  
Leukocyte Population ◽  
Simple Set ◽  
Intervention Efficacy ◽  
Underlying Diseases

Age-associated changes in human hematopoiesis have been mostly recapitulated in mouse models; but not much has been explored in rats, a physiologically closer model to humans. To establish whether rat hematopoiesis closely mirrors humans’, we examined the peripheral blood of rats throughout their lifespan. Significant age-associated changes showed distinctive population shifts predictive of age. A divergence between predicted versus chronological age changes was indicative of fragility; thus, these data may be a valuable tool to identify underlying diseases or as a surrogate predictor for intervention efficacy. Notably, several blood parameters and DNA methylation alterations defined specific leverage points during aging, supporting non-linear aging effects and highlighting a roadmap for interventions at these junctures. Overall, we present a simple set of rat blood metrics that can provide a window into their health and inform the implementation of interventions in a model system physiologically relevant for humans.

scholarly journals Epigenetic clock and DNA methylation studies of roe deer in the wild

2020 ◽  
Author(s):  
Jean-François Lemaître ◽  
Benjamin Rey ◽  
Jean-Michel Gaillard ◽  
Corinne Régis ◽  
Emmanuelle Gilot ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Evolutionary Biology ◽  
Roe Deer ◽  
Chronological Age ◽  
Epigenetic Clock ◽  
Aging Effects ◽  
Methylation Array ◽  
Biomarkers Of Aging ◽  
Epigenetic Age ◽  
The Relationship

AbstractDNA methylation-based biomarkers of aging (epigenetic clocks) promise to lead to new insights in the evolutionary biology of ageing. Relatively little is known about how the natural environment affects epigenetic aging effects in wild species. In this study, we took advantage of a unique long-term (>40 years) longitudinal monitoring of individual roe deer (Capreolus capreolus) living in two wild populations (Chizé and Trois Fontaines, France) facing different ecological contexts to investigate the relationship between chronological age and levels of DNA methylation (DNAm). We generated novel DNA methylation data from n=90 blood samples using a custom methylation array (HorvathMammalMethylChip40). We present three DNA methylation-based estimators of age (DNAm or epigenetic age), which were trained in males, females, and both sexes combined. We investigated how sex differences influenced the relationship between DNAm age and chronological age through the use of sex-specific epigenetic clocks. Our results highlight that both populations and sex influence the epigenetic age, with the bias toward a stronger male average age acceleration (i.e. differences between epigenetic age and chronological ages) particularly pronounced in the population facing harsh environmental conditions. Further, we identify the main sites of epigenetic alteration that have distinct aging patterns across the two sexes. These findings open the door to promising avenues of research at the crossroad of evolutionary biology and biogerontology.

scholarly journals Leukotriene C4biosynthesis in isolated August rat peritoneal leukocytes

1996 ◽  
Vol 5 (6) ◽  
pp. 443-447
Author(s):  
J. M. Huebner ◽  
R. R. Eversole ◽  
W. F. Jackson ◽  
C. D. Mackenzie ◽  
S. R. Stapleton ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Experimental Model ◽  
Model System ◽  
Ionophore A23187 ◽  
Leukocyte Population ◽  
Kinase C ◽  
Maximal Stimulation ◽  
Peritoneal Leukocytes ◽  
Isolated Cell

The mixed leukocyte population obtained from the peritoneum of the August rat is a potentially important experimental model of inherent eosinophilia that has not been well characterized. In the present study, isolated cell preparations generated a concentration-dependent release of leukotriene (LT) C4when exposed to the Ca2+ionophore A23187, reaching maximal stimulation at 5.0 μM. This response was inhibited by the 5-lipoxygenase activating protein antagonist MK-886 (0.1 μM), nominally Ca2+and Mg2+-free incubation media and by activation of protein kinase C via phorbol 12-myristate 13-acetate (50 nM). These findings establish a model system for investigating LTC4profiles contingent with innate peritoneal eosinophilia and are consistent with the hypothesis that cellular LTC4biosynthesis is phosphoregulated.

scholarly journals Using Dental Age to Estimate Chronological Age in Czech Children Aged 3–18 Years

2015 ◽  
Vol 116 (2) ◽  
pp. 139-154
Author(s):  
Kristina Ginzelová ◽  
Taťjana Dostálová ◽  
Hana Eliášová ◽  
Alex Vinšů ◽  
Antonín Buček ◽  
...  
Keyword(s):  
Age Estimation ◽  
Statistical Evaluation ◽  
Tooth Development ◽  
Chronological Age ◽  
Age Group ◽  
Dental Age ◽  
Dental Age Estimation ◽  
Mean Values ◽  
The Mean ◽  
Underlying Diseases

The Demirjian methods to determine dental age are based on analysis of orthopantograms. The dental age estimation is based on establishing the tooth development stages. The purpose of this study was to assess the accuracy of estimation of dental age by Demirjian in the use of all of his four methods. 505 Czech healthy boys and girls aged 3 to 18 years were examined radiographically at the Department of Stomatology, Second Faculty of Medicine, Charles University in Prague. It was mentioned the factors of underlying diseases influence the accuracy of the dental age estimation. For statistical evaluation, descriptive statistics was used to compare deviations of the mean values of chronological and dental age in each age group. The resulting difference between dental age and chronological age is not significant in both genders only when using both Demirjian 7-teeth methods of 1973 and 1976. Therefore these may be most appropriately used for forensic age estimation. There are shown standard deviation differences in different countries. Demirjian’s original 7-teeth method from 1973 and Demirjian’s revised 4-teeth method from 1976 appear to be the best methods for calculating the dental age of healthy Czech children of both genders.

scholarly journals Chlorophyll enhances oxidative stress tolerance inCaenorhabditis elegansand extends its lifespan

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1879 ◽  
Author(s):  
Erjia Wang ◽  
Michael Wink
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Secondary Metabolites ◽  
Model System ◽  
The Body ◽  
Aging Effects ◽  
Oxidative Stress Tolerance ◽  
C Elegans ◽  
Dependent Pathway

Green vegetables are thought to be responsible for several beneficial properties such as antioxidant, anti-mutagenic, and detoxification activities. It is not known whether these effects are due to chlorophyll which exists in large amounts in many foods or result from other secondary metabolites. In this study, we used the model systemCaenorhabditis elegansto investigate the anti-oxidative and anti-aging effects of chlorophyllin vivo. We found that chlorophyll significantly improves resistance to oxidative stress. It also enhances the lifespan ofC. elegansby up to 25% via activation of the DAF-16/FOXO-dependent pathway. The results indicate that chlorophyll is absorbed by the worms and is thus bioavailable, constituting an important prerequisite for antioxidant and longevity-promoting activities inside the body. Our study thereby supports the view that green vegetables may also be beneficial for humans.

scholarly journals Reliability of the individual age assessment at the time of death based on sternal rib-ends' morphology in Balkan population

2005 ◽  
Vol 62 (6) ◽  
pp. 441-446 ◽  
Author(s):  
Danijela Djonic ◽  
Marija Djuric ◽  
Dragan Babic ◽  
Djordje Popovic
Keyword(s):  
Chronological Age ◽  
Phase Method ◽  
Time Of Death ◽  
Age Changes ◽  
Age Assessment ◽  
Males And Females ◽  
Discriminative Analysis ◽  
The Individual ◽  
Sternal Rib

This paper analyzes the reliability of the I?can?s sternal rib-ends phase method for the assessment of individual age at the time of death in the Balkan population. The method is based on the morphological age changes of the sternal rib ends. The tested samples consisted of 65 ribs from autopsy cases in the Institute for Forensic Medicine, University of Belgrade, during 1999-2002 (23 females, and 42 males of various ages, ranged from 17-91 years), according to the forensic documents. Significant differences between the real chronological age of the individuals and the values established by the I?can?s method was found, especially in the older categories (phases 6 and 7), in both males and females. The results of the discriminative analysis showed the values of the highest diagnostic relevance for the assessment of age in our population: the change of the depth of the articular fossa, the thickness of its walls, and the quality of the bones.

Age changes in blood of the golden hamster

1961 ◽  
Vol 200 (5) ◽  
pp. 1018-1022 ◽  
Author(s):  
E. L. House ◽  
B. Pansky ◽  
M. S. Jacobs
Keyword(s):  
Golden Hamster ◽  
Gamma Globulin ◽  
Blood Parameters ◽  
Age Changes ◽  
Gradual Decline ◽  
Initial Values ◽  
Beta Globulin

Studies were made on 500 male hamsters, ranging in age from 4 weeks to 1 year. Significant changes from the initial values of blood parameters established in the 4-week-old hamster were the following: a) neutropenia and lymphocytosis at 8 weeks with a return to the basic values by 1 year; b) sustained elevation of hematocrit values beginning at 8 weeks; c) a small increase in hemoglobin, persistent after 8 weeks; d) gradual decline in albumin during the 1st year; e) an elevation of the alpha-2 globulin by the 6th month; f) a decreased beta globulin beginning at 8 weeks; g) alternating increase, decrease, and increase of the gamma globulin-fibrinogen factor, at 8 weeks, 6 months, and 1 year, respectively; h) a decline in the A/G (albumin/globulin) ratio with increasing age; i) an increase in the albumin lipoprotein and a drop in the beta-gamma lipoprotein with advancing age. The fibrinogen of hamster plasma was linked to gamma globulin.

scholarly journals Evolutionary Explanations of the “Actuarial Senescence in the Wild” and of the “State of Senility”

2006 ◽  
Vol 6 ◽  
pp. 1086-1108 ◽  
Author(s):  
Giacinto Libertini
Keyword(s):  
Inverse Correlation ◽  
Mutation Accumulation ◽  
The State ◽  
Chronological Age ◽  
Large Set ◽  
Age Changes ◽  
Extrinsic Mortality ◽  
Associated Diseases ◽  
In The Wild ◽  
Genetically Determined

A large set of data suggests that progressive reduction of fitness and senile decay in vertebrates are in correlation with the decline of cell replication capacities. However, the limits in such capacities are hardly explained in evolutionarily terms by current gerontological theories that rule out fitness decline as something genetically determined and regulated, and therefore somehow favored by natural selection.Four theories are tested as possible explanations of the “increasing mortality with increasing chronological age in populations in the wild” (“IMICAW”[1]), alias “actuarial senescence in the wild”[2], and of the observed negative correlation between extrinsic mortality and the ratio between deaths due to intrinsic mortality and deaths due to extrinsic mortality. Only the theory attributing an adaptive value to IMICAW allows an evolutionary explanation for it and for the aforesaid inverse correlation, while the other three theories (“mutation accumulation”, “antagonistic pleiotropy”, and “disposable soma” th.) even predict a positive correlation.Afterwards, the same theories are tested as possible explanations for the “state of senility”[3], namely the deteriorated state of individuals in artificially protected conditions (captivity, civilization, etc.) at ages rarely or never observable in the wild. With the distinction between “damage resulting from intrinsic living processes”[4], alias “age changes”[5], and “age-associated diseases”[4,5], the same theory explaining IMICAW allows a rational interpretation of the first category of phenomena while another theory, the “mutation accumulation” hypothesis, gives an immediate interpretation for the second category.The current gerontological paradigm explaining the increasing mortality with increasing chronological age as consequence of insufficient selection should be restricted to the “age-associated diseases”. For IMICAW, it should be substituted with the concept of a physiologic phenomenon genetically determined by a balance of opposite selective pressures — strictly in terms of kin selection — and, for “age changes”, with the action of the same IMICAW-causing mechanisms at ages when selection becomes ineffective.

A Protozoan Model for Golgi-Associated Calcification

1971 ◽  
Vol 29 ◽  
pp. 332-333
Author(s):  
D. C. Williams ◽  
D. E. Outka
Keyword(s):  
Golgi Apparatus ◽  
Organic Matrix ◽  
Model System ◽  
Sequential Formation

Many studies have shown that the Golgi apparatus is involved in a variety of synthetic activities, and probably no Golgi product is more elaborate than the scales produced by various kinds of phytoflagellates. The formation of calcified scales (coccoliths, Fig. 1,2) of the coccolithophorid phytoflagellates provides a particularly interesting model system for the study of biological mineralization, and the sequential formation of Golgi products.The coccoliths of Hymenomonas carterae consist of a scale-like base (Fig. 2 and 4, b) with a highly structured calcified (CaCO3) rim composed of two distinct elements which alternate about the base periphery (Fig. 1 and 3, A, B). Each element is enveloped by a sheath-like organic matrix (Fig. 3; Fig. 4, m).

The ultrastructure of acinar cells in the external orbital gland of young and old male rats

1978 ◽  
Vol 36 (2) ◽  
pp. 276-277
Author(s):  
R. Carriere
Keyword(s):  
Young Adulthood ◽  
Acinar Cells ◽  
Cell Number ◽  
Male Rats ◽  
Polyploid Cell ◽  
Secretory Cells ◽  
Age Changes ◽  
Albino Rat ◽  
Golgi Membranes ◽  
Diploid Cells

The external orbital gland of the albino rat exhibits both sexual dimorphism and histological age changes. In males, many cells attain a remarkable degree of polyploidy and an increase of polyploid cell number constitutes the major age change until young adulthood. The acini of young adults have a small lumen and are composed of tall serous cells. Subsequently, many acini acquire a larger lumen with an irregular outline while numerous vacuoles accumulate throughout the secretory cells. At the same time, vesicular acini with a large lumen surrounded by pale-staining low cuboidal diploid cells begin to appear and their number increases throughout old age. The fine structure of external orbital glands from both sexes has been explored and in considering acinar cells from males, emphasis was given to the form of the Golgi membranes and to nuclear infoldings of cytoplasmic constituents.

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