62 research outputs found

    Immunogenetics of an antigen identified in both sheep and cattle sera.

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    SUMMARYAlloimmunization in sheep revealed an antigen specificity B1 which is also to be found in cattle sera. The molecular weight of the protein carrying B1 was greater in sheep than in cattle, whilst in both cases its isoelectric point was at pH 6·2. The electrophoretic position of the antigen suggests that the molecule carrying B1 might be a β-globulin. Family studies indicated that in both species B1 was inherited in a simple Mendelian manner, as if it were a product of a dominant alleleB1at an autosomal locusB

    Strikingly higher frequency in centenarians and twins of mtDNA mutation causing remodeling of replication origin in leukocytes

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    The presence of a genetic component in longevity is well known. Here, the association of a mtDNA mutation with a prolonged life span in humans was investigated. Large-scale screening of the mtDNA main control region in leukocytes from subjects of an Italian population revealed a homoplasmic C150T transition near an origin of heavy mtDNA-strand synthesis in approximate to 17% of 52 subjects 99-106 years old, but, in contrast, in only 3.4% of 117 younger individuals (P = 0.0035). Evidence was obtained for the contribution of somatic events, under probable nuclear genetic control, to the striking selective accumulation of the mutation in centenarians. In another study, among leukocyte mtDNA samples from 20 monozygotic and 18 dizygotic twins, 60-75 years old, 30% (P = 0.0007) and 22% (P = 0.011), respectively, of the individuals involved exhibited the homoplasmic C150T mutation. In a different system, i.e., in five human fibroblast longitudinal studies, convincing evidence for the aging-related somatic expansion of the C150T mutation, up to homoplasmy, was obtained. Most significantly, 5' end analysis of nascent heavy mtDNA strands consistently revealed a new replication origin at position 149, substituting for that at 151, only in C150T mutation carrying samples of fibroblasts or immortalized lymphocytes. Considering the aging-related health risks that the centenarians have survived and the developmental risks of twin gestations, it is proposed that selection for a remodeled replication origin, inherited or somatically acquired, provides a survival advantage and underlies the observed high incidence of the C150T mutation in centenarians and twins

    Mitochondrial DNA involvement in human longevity

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    AbstractThe main message of this review can be summarized as follows: aging and longevity, as complex traits having a significant genetic component, likely depend on a number of nuclear gene variants interacting with mtDNA variability both inherited and somatic. We reviewed the data available in the literature with particular attention to human longevity, and argued that what we hypothesize for aging and longevity could have a more general relevance and be extended to other age-related complex traits such as Alzheimer's and Parkinson's diseases. The genetics which emerges for complex traits, including aging and longevity, is thus even more complicated than previously thought, as epistatic interactions between nuclear gene polymorphisms and mtDNA variability (both somatic and inherited) as well as between mtDNA somatic mutations (tissue specific) and mtDNA inherited variants (haplogroups and sub-haplogroups) must be considered as additional players capable of explaining a part of the aging and longevity phenotype. To test this hypothesis is one of the main challenge in the genetics of aging and longevity in the next future

    The mitochondrial DNA control region shows genetically correlated levels of heteroplasmy in leukocytes of centenarians and their offspring

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    <p>Abstract</p> <p>Background</p> <p>Studies on heteroplasmy occurring in the mitochondrial DNA (mtDNA) control region (CR) in leukocytes of centenarians and younger subjects have shown that the C150T somatic transition is over-represented in centenarians. However, whether the occurrence/accumulation of heteroplasmy is a <it>phenotypic consequence </it>of extreme ageing or a <it>genetically controlled event </it>that may favor longevity is a question that deserves further attention. To clarify this point, we set up a Denaturing High Performance Liquid Chromatography (DHPLC) protocol to quantify mtDNA CR heteroplasmy. We then analyzed heteroplasmy in leukocytes of centenarians (100 subjects), their offspring and nieces/nephews (200 subjects, age-range 65–80 years, median age 70 years), and in leukocytes of 114 control subjects sex- and age-matched with the relatives of centenarians.</p> <p>Results</p> <p>The centenarians and their descendants, despite the different ages, showed similar levels of heteroplasmy which were significantly higher than levels in controls. In addition we found that heteroplasmy levels were significantly correlated in parent-offspring pairs (r = 0.263; p = 0.009), but were independent of mtDNA inherited variability (haplogroup and sequence analyses).</p> <p>Conclusion</p> <p>Our findings suggest that the high degree of heteroplasmy observed in centenarians is genetically controlled, and that such genetic control is independent of mtDNA variability and likely due to the nuclear genome.</p

    Ethical Criteria for the Admission and Management of Patients in the ICU Under Conditions of Limited Medical Resources: A Shared International Proposal in View of the COVID-19 Pandemic

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    Introduction The present pandemic has exposed us to unprecedented challenges that need to be addressed not just for the current state, but also for possible future similar occurrences. It is worth pointing out that discussions on the allocation of medical resources may not necessarily refer to an exception, but, unfortunately, to a regular condition for a large part of humanity (1). The criteria for admission to an Intensive Care Unit (ICU) setting generally take into account multiple factors. There must be a diagnostic and prognostic basis for the decisions made, considering both biological factors and patient values and wishes. Furthermore, the decision-making process should, whenever possible, respect the patient's advance directives as well as the relationship with the patient's family or attorney. Therapeutic neglect should be avoided. Having applied standard clinical evaluation criteria for the appropriate treatment of patients with COVID-19, including consideration of prognosis, if a hospital then finds itself unable to provide optimal treatment (e.g., due to a disproportion between the number of patients and the availability of beds, healthcare providers, ventilators, and drugs in the ICU), it becomes necessary to evaluate, case by case, how to achieve justice and the best possible good for the greatest number of patients. It is therefore mandatory to explore alternative solutions; these include increasing available beds and healthcare providers, implementing alternative, though suboptimal, approaches (where appropriate), transferring patients to other clinical units, etc. Making these decisions properly also involves the recovery of the political role of medicine and science (2). If the imbalance between needs and resources reaches a critical level, an emergency triage protocol, following the operational and ethical indications of “disaster medicine,” should be activated. These have been deployed in major and serious natural (earthquakes or tsunamis for example) and technological (factory explosions, public transport accidents for example) disasters, as well as following terrorist attacks (3, 4). The question of the feasibility of developing a clinical evaluation algorithm to support the decision-making of the triage team remains open, though many such protocols have been written. According to the above, we propose the following five ethical criteria for the triage of patients in conditions of limited resources, such as the COVID pandemic. They are the result of an interdisciplinary and intercultural dialogue between specialists from different disciplines. Several of the authors are working in the main epicenters of the crisis and currently are playing a central role in the bioethical, clinical, social and legal aspects of the management of the COVID-19 pandemic

    MtDNA variability and nuclear gene expression in oxidative stress response: Sirtuins and Transcription Factors

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    Dottorato di Ricerca in Molecular Bio-Pathology, XX Cycle, 2008UniversitĂ  della Calabri

    Analysis of C538T polymorphims of the SSADH gene in humans: functional and evolutionary aspects

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    Dottorato di Ricerca in Molecular Bio-Pathology, XX Cycle, 2007UniversitĂ  della Calabri
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