scholarly journals Age-Dependent Decline in Salinity Tolerance in a Euryhaline Fish

2021 ◽  
Vol 2 ◽  
Author(s):  
Mayu Inokuchi ◽  
Yoko Yamaguchi ◽  
Benjamin P. Moorman ◽  
Andre P. Seale

Euryhaline teleost fish are characterized by their ability to tolerate a wide range of environmental salinities by modifying the function of osmoregulatory cells and tissues. In this study, we experimentally addressed the age-related decline in the sensitivity of osmoregulatory transcripts associated with a transfer from fresh water (FW) to seawater (SW) in the euryhaline teleost, Mozambique tilapia, Oreochromis mossambicus. The survival rates of tilapia transferred from FW to SW were inversely related with age, indicating that older fish require a longer acclimation period during a salinity challenge. The relative expression of Na+/K+/2Cl− cotransporter 1a (nkcc1a), which plays an important role in hyposmoregulation, was significantly upregulated in younger fish after SW transfer, indicating a clear effect of age in the sensitivity of branchial ionocytes. Prolactin (Prl), a hyperosmoregulatory hormone in O. mossambicus, is released in direct response to a fall in extracellular osmolality. Prl cells of 4-month-old tilapia were sensitive to hyposmotic stimuli, while those of >24-month-old fish did not respond. Moreover, the responsiveness of branchial ionocytes to Prl was more robust in younger fish. Taken together, multiple aspects of osmotic homeostasis, from osmoreception to hormonal and environmental control of osmoregulation, declined in older fish. This decline appears to undermine the ability of older fish to survive transfer to hyperosmotic environments.

Author(s):  
Karla Romero Starke ◽  
Gabriela Petereit-Haack ◽  
Melanie Schubert ◽  
Daniel Kämpf ◽  
Alexandra Schliebner ◽  
...  

Increased age appears to be a strong risk factor for COVID-19 severe outcomes. However, studies do not sufficiently consider the age-dependency of other important factors influencing the course of disease. The aim of this review was to quantify the isolated effect of age on severe COVID-19 outcomes. We searched Pubmed to find relevant studies published in 2020. Two independent reviewers evaluated them using predefined inclusion and exclusion criteria. We extracted the results and assessed seven domains of bias for each study. After adjusting for important age-related risk factors, the isolated effect of age was estimated using meta-regression. Twelve studies met our inclusion criteria: four studies for COVID-19 disease severity, seven for mortality, and one for admission to ICU. The crude effect of age (5.2% and 13.4% higher risk of disease severity and death per age year, respectively) substantially decreased when adjusting for important age-dependent risk factors (diabetes, hypertension, coronary heart disease/cerebrovascular disease, compromised immunity, previous respiratory disease, renal disease). Adjusting for all six comorbidities indicates a 2.7% risk increase for disease severity (two studies), and no additional risk of death per year of age (five studies). The indication of a rather weak influence of age on COVID-19 disease severity after adjustment for important age-dependent risk factors should be taken in consideration when implementing age-related preventative measures (e.g., age-dependent work restrictions).


1993 ◽  
Vol 13 (2) ◽  
pp. 310-314 ◽  
Author(s):  
Juha O. Rinne ◽  
Jarmo Hietala ◽  
Ulla Ruotsalainen ◽  
Erkki Säkö ◽  
Arto Laihinen ◽  
...  

The effect of age on human striatal dopamine D2 receptors was investigated with positron emission tomography (PET) using [11C]raclopride as a radioligand. Twenty-one healthy volunteers aged from 20 to 81 years were studied. An equilibrium method was applied and two separate PET scans with different specific activities of [11C]raclopride were performed. The maximal number of receptors ( Bmax) and their dissociation constant ( Kd) were calculated using Scatchard analysis. There was an age-dependent decline in the Bmax ( r = 0.49; p = 0.02) of striatal D2 receptors while the Kd remained unchanged. The results show that there is an age-related loss of striatal D2 receptors, which, together with other changes in the brain nigrostriatal dopaminergic system, may contribute to extrapyramidal symptoms associated with aging.


2016 ◽  
Vol 63 (4) ◽  
Author(s):  
Mohaddeseh Ahmadnezhad ◽  
Shahrbanoo Oryan ◽  
Mahmoud Bahmani ◽  
Mohammad Sayad Bourani

Gill morphology and branchial ionocyte variability were examined in zander Sander lucioperca (Linnaeus, 1758)fingerlings, having two different body weights (1 and 2 g) for a period of ten days following their transfer from freshwater to two different salinities (7 and 12‰ Caspian Sea water) using Na+, K+-ATPase (NKA) immunolocalisation. Survival rates and plasma osmolarity levels at the end of each salinity challenge were measured. By the end of the experiment, bothweight groups were able to survive and successfully acclimate to salinity change. The number and size of branchial ionocytes in the gills dramatically decreased in both size groups; while, the filament ionocytes in both weight groups reformed at the end of the acclimation period. The results indicated both groups to be in the same osmoregulatory developmental stage, despite difference in their body weight. Also, their blood osmotic pressure and gill ionocyte changes at different salinity were similar when transferred to iso-osmotic condition. Further studies are needed for complete understanding of zander osmoregulatory systems exposed to different salinities.


2000 ◽  
Vol 39 (05) ◽  
pp. 127-132 ◽  
Author(s):  
Nicole Sieweke ◽  
K. H. Bohuslavizki ◽  
W. U. Kampen ◽  
M. Zuhayra ◽  
M. Clausen ◽  
...  

Summary Aim of this study was to validate a recently introduced new and easy-to-perform method for quantifying bone uptake of Tc-99m-labelled diphosphonate in a routine clinical setting and to establish a normal data base for bone uptake depending on age and gender. Methods: In 49 women (14-79 years) and 47 men (6-89 years) with normal bone scans as well as in 49 women (33-81 years) and 37 men (27-88 years) with metastatic bone disease whole-body bone scans were acquired at 3 min and 3-4 hours p.i. to calculate bone uptake after correction for both urinary excretion and soft tissue retention. Results: Bone uptake values of various age-related subgroups showed no significant differences between men and women (p >0.05 ). Furthermore, no differences could be proven between age-matched subgroups of normals and patients with less than 10 metastatic bone lesions, while patients with wide-spread bone metastases revealed significantly increased uptake values. In both men and women highest bone uptake was obtained (p <0.05 ) in subjects younger than 20 years with active epiphyseal growth plates. In men, bone uptake slowly decreased with age up to 60 years and then showed a tendency towards increasing uptake values. In women, the mean uptake reached a minimun in the decade 20-29 years and then slowly increased with a positive linear correlation of age and uptake in subjects older than 55 years (r = 0.57). Conclusion: Since the results proposed in this study are in good agreement with data from literature, the new method used for quantification could be validated in a large number of patients. Furthermore, age- and sexrelated normal bone uptake values of Tc-99m-HDP covering a wide range of age could be presented for this method as a basis for further studies on bone uptake.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 313-314
Author(s):  
Darlingtina Esiaka ◽  
Alice Cheng ◽  
Candidus Nwakasi

Abstract Self-acknowledgement and integration of racial and sexual identities are significant to one’s overall sense of identity because of their implications for mental health and wellbeing. These issues are important as one ages because older people experience a wide range of factors that add layers to their ability to (re)integrate subsets of their identity into their overall self-identity such as age and age-related disabilities. This study examined the intersection of race and sexual identities on overall health status in older Black gay men, a demographic group that has historically received less attention. Data from the Social Justice Sexuality (SJS) survey of LGBTQ+ people of color which occurred over a 12-month period in the United States were analyzed. Participants (N=160), 50 years and over, responded to questions about their sexuality, social identity, family dynamics, community connection and engagement, and mental and physical health. Results show an association of mental wellbeing with racial and sexual identities. Further, results show that a strong sense of connection to other sexual minorities is positively associated with mental health in older Black gay men. We discuss the implication of findings for mental health interventions targeting this gendered population.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1417
Author(s):  
Binafsha M. Syed ◽  
Andrew R. Green ◽  
Emad A. Rakha ◽  
David A.L. Morgan ◽  
Ian O. Ellis ◽  
...  

As age advances, breast cancer (BC) tends to change its biological characteristics. This study aimed to explore the natural progression of such changes. The study included 2383 women with clinically T0-2N0-1M0 BC, managed by primary surgery and optimal adjuvant therapy in a dedicated BC facility. Tissue micro-arrays were constructed from their surgical specimens and indirect immunohistochemistry was used for analysis of a large panel (n = 16) of relevant biomarkers. There were significant changes in the pattern of expression of biomarkers related to luminal (oestrogen receptor (ER), progesterone receptors (PgR), human epidermal growth factor receptor (HER-2), E-cadherin, MUC1, bcl2 CK7/8, CK18 and bcl2) and basal (CK5/6, CK14, p53 and Ki67) phenotypes, lymph node stage, histological grade and pathological size when decade-wise comparison was made (p < 0.05). The ages of 40 years and 70 years appeared to be the milestones marking a change of the pattern. There were significantly higher metastasis free and breast cancer specific survival rates among older women with ER positive tumours while there was no significant difference in the ER negative group according to age. Biological characteristics of BC show a pattern of change with advancing age, where 40 years and 70 years appear as important milestones. The pattern suggests <40 years as the phase with aggressive phenotypes, >70 years as the less aggressive phase and 40–70 years being the transitional phase.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 96-96
Author(s):  
Victoria Raveis ◽  
Simona Kwon

Abstract Women have a 1-in-8 lifetime risk of breast cancer. Earlier diagnosis and treatment advances have improved 15- and 20-year survival rates. Increased survival can mean coping with the effects of cancer and its treatment over an extended period of time, while experiencing age-related changes in functioning and the emergence of other health issues. To explore breast cancer survivors’ perspectives on their issues and concerns across the life-course, focus groups were conducted with a culturally diverse sample (N=18) of survivors (72% white, 28% Black, 11% Hispanic). Participants were 44-82 years old. Most, 83% were 50 and older, 56% were 60 and older. The majority (83%) were diagnosed in their 40’s and 50’s. Two were diagnosed in their early 30’s and one at age 68. Participants reaffirmed the necessity, as a breast cancer survivor, of being a life-long health advocate on their own behalf, and the importance of being self-informed. As one woman commented: “Knowledge is power”. Survivors shared that their emergent health issues were complicated by their cancer history, and, that, as a cancer survivor, “I never stop worrying”. A widespread concern was not knowing if the health issues and co-morbidities they experienced (such as joint pain, neuropathy, tendinitis, heart disease), were age-related, a consequence of their cancer, or a late treatment effect. An overriding sentiment expressed was that clinicians have not recognized the importance of quality of life in cancer survival. As a survivor succinctly stated: “We are living longer, but we need to live long with quality of life.”


2021 ◽  
Author(s):  
Yesa Yang ◽  
Hannah Dunbar

Endpoint development trials are underway across the spectrum of retinal disease. New validated endpoints are urgently required for the assessment of emerging gene therapies and in preparation for the arrival of novel therapeutics targeting early stages of common sight-threatening conditions such as age-related macular degeneration. Visual function measures are likely to be key candidates in this search. Over the last two decades, microperimetry has been used extensively to characterize functional vision in a wide range of retinal conditions, detecting subtle defects in retinal sensitivity that precede visual acuity loss and tracking disease progression over relatively short periods. Given these appealing features, microperimetry has already been adopted as an endpoint in interventional studies, including multicenter trials, on a modest scale. A review of its use to date shows a concurrent lack of consensus in test strategy and a wealth of innovative disease and treatment-specific metrics which may show promise as clinical trial endpoints. There are practical issues to consider, but these have not held back its popularity and it remains a widely used psychophysical test in research. Endpoint development trials will undoubtedly be key in understanding the validity of microperimetry as a clinical trial endpoint, but existing signs are promising.


2021 ◽  
Vol 22 (4) ◽  
pp. 1539
Author(s):  
Paola De Sanctis ◽  
Giuseppe Filardo ◽  
Provvidenza Maria Abruzzo ◽  
Annalisa Astolfi ◽  
Alessandra Bolotta ◽  
...  

In a previous study, the whole transcriptome of the vastus lateralis muscle from sedentary elderly and from age-matched athletes with an exceptional record of high-intensity, life-long exercise training was compared—the two groups representing the two extremes on a physical activity scale. Exercise training enabled the skeletal muscle to counteract age-related sarcopenia by inducing a wide range of adaptations, sustained by the expression of protein-coding genes involved in energy handling, proteostasis, cytoskeletal organization, inflammation control, and cellular senescence. Building on the previous study, we examined here the network of non-coding RNAs participating in the orchestration of gene expression and identified differentially expressed micro- and long-non-coding RNAs and some of their possible targets and roles. Unsupervised hierarchical clustering analyses of all non-coding RNAs were able to discriminate between sedentary and trained individuals, regardless of the exercise typology. Validated targets of differentially expressed miRNA were grouped by KEGG analysis, which pointed to functional areas involved in cell cycle, cytoskeletal control, longevity, and many signaling pathways, including AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR), which had been shown to be pivotal in the modulation of the effects of high-intensity, life-long exercise training. The analysis of differentially expressed long-non-coding RNAs identified transcriptional networks, involving lncRNAs, miRNAs and mRNAs, affecting processes in line with the beneficial role of exercise training.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manjot Kaur Grewal ◽  
Shruti Chandra ◽  
Alan Bird ◽  
Glen Jeffery ◽  
Sobha Sivaprasad

AbstractTo evaluate the effect of aging, intra- and intersession repeatability and regional scotopic sensitivities in healthy and age-related macular degeneration (AMD) eyes. Intra- and intersession agreement and effect of age was measured in healthy individuals. The mean sensitivity (MS) and pointwise retinal sensitivities (PWS) within the central 24° with 505 nm (cyan) and 625 nm (red) stimuli were evaluated in 50 individuals (11 healthy and 39 AMD eyes). The overall intra- and intersession had excellent reliability (intraclass correlation coefficient, ICC > 0.90) and tests were highly correlated (Spearman rs = 0.75–0.86). Eyes with subretinal drusenoid deposit (SDD) had reduced PWS centrally, particularly at inferior and nasal retinal locations compared with controls and intermediate AMD (iAMD) without SDD. There was no difference in MS or PWS at any retinal location between iAMD without SDD and healthy individuals nor between iAMD with SDD and non-foveal atrophic AMD groups. Eyes with SDD have reduced rod function compared to iAMD without SDD and healthy eyes, but similar to eyes with non-foveal atrophy. Our results highlight rod dysfunction is not directly correlated with drusen load and SDD location.


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