scholarly journals Nucleotide Variability atG6pdand the Signature of Malarial Selection in Humans

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1849-1861 ◽  
Author(s):  
Matthew A Saunders ◽  
Michael F Hammer ◽  
Michael W Nachman

AbstractGlucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy in humans. Deficiency alleles for this X-linked disorder are geographically correlated with historical patterns of malaria, and the most common deficiency allele in Africa (G6PD A-) has been shown to confer some resistance to malaria in both hemizygous males and heterozygous females. We studied DNA sequence variation in 5.1 kb of G6pd from 47 individuals representing a worldwide sample to examine the impact of selection on patterns of human nucleotide diversity and to infer the evolutionary history of the G6PD A-allele. We also sequenced 3.7 kb of a neighboring locus, L1cam, from the same set of individuals to study the effect of selection on patterns of linkage disequilibrium. Despite strong clinical evidence for malarial selection maintaining G6PD deficiency alleles in human populations, the overall level of nucleotide heterozygosity at G6pd is typical of other genes on the X chromosome. However, the signature of selection is evident in the absence of genetic variation among A-alleles from different parts of Africa and in the unusually high levels of linkage disequilibrium over a considerable distance of the X chromosome. In spite of a long-term association between Plasmodium falciparum and the ancestors of modern humans, patterns of nucleotide variability and linkage disequilibrium suggest that the A-allele arose in Africa only within the last 10,000 years and spread due to selection.

2020 ◽  
Vol 26 (43) ◽  
pp. 5609-5616
Author(s):  
Sarantis Livadas ◽  
Christina Bothou ◽  
Djuro Macut

Early activation of the adrenal zona reticularis, leading to adrenal androgen secretion, mainly dehydroepiandrosterone sulfate (DHEAS), is called premature adrenarche (PA). The fact that adrenal hyperandrogenism in females has been linked to a cluster of cardiovascular (CV) risk factors, even in prepubertal children, warrants investigation. Controversial results have been obtained in this field, probably due to genetic, constitutional, and environmental factors or differences in the characteristics of participants. In an attempt to understand, in depth, the impact of PA as a potential activator of CV risk, we critically present available data stratified according to pubertal status. It seems that prepubertally, CV risk is increased in these girls, but is somewhat attenuated during their second decade of life. Furthermore, different entities associated with PA, such as polycystic ovary syndrome, non-classical congenital adrenal hyperplasia, heterozygosity of CYP21A2 mutations, and the impact of DHEAS on CV risk, are reviewed. At present, firm and definitive conclusions cannot be drawn. However, it may be speculated that girls with a history of PA display a hyperandrogenic hormonal milieu that may lead to increased CV risk. Accordingly, appropriate long-term follow-up and early intervention employing a patient-oriented approach are recommended.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chin Ee Ho ◽  
You Li Goh ◽  
Chang Zhang

Rhizoma Coptidis (RC), commonly known ashuanglian, is a herb frequently used in Traditional Chinese Medicine (TCM) prescriptions. Known to have “clearing damp-heat, quenching fire and counteracting poison” properties, it was widely used in the Chinese community in Singapore. Berberine, an alkaloid isolated from RC, is known to have a wide array of therapeutic effects including antimicrobial, antineoplastic, and hepatoprotective effects. In 1978, RC was implicated in causing neonatal jaundice (NNJ) and kernicterus in neonates suffering from glucose-6-phosphate dehydrogenase (G6PD) deficiency, leading to the banning of RC and berberine in Singapore. More than three decades later, accumulating evidence-based studies pointing to the safety of RC for general public and better understanding of G6PD deficiency, the Health Sciences Authority (HSA) in Singapore reviewed and lifted the prohibition on RC and berberine, turning a brand new chapter in the history of TCM in Singapore. This paper aims to review the safety of RC and berberine, using the prohibition of use and subsequent lifting of ban on RC and berberine in Singapore as an illustration to highlight the importance of evidence-based studies in Traditional Chinese Medicine (TCM).


Genetics ◽  
1977 ◽  
Vol 86 (1) ◽  
pp. 199-212
Author(s):  
G Filippi ◽  
A Rinaldi ◽  
R Palmarino ◽  
E Seravalli ◽  
M Siniscalco

ABSTRACT The distribution of four X-linked mutants (G6PD, Deutan, Protan and Xg) among lowland and once highly malarial populations of Sardinia discloses a clear-cut example of linkage disequilibrium between two of them (G6PD and Protan). In the same populations the distribution of G6PD-deficiency versus colorblindness of the Deutan type and the Xg blood-group is not significantly different from that expected at equilibrium. These data suggest indirectly that the loci for G6PD and Protan may be nearer to one another than those for G6PD and Deutan.


2021 ◽  
Author(s):  
Daniel J. Cotter ◽  
Timothy H. Webster ◽  
Melissa A. Wilson

AbstractMutation, recombination, selection, and demography affect genetic variation across the genome. Increased mutation and recombination both lead to increases in genetic diversity in a region-specific manner, while complex demographic patterns shape patterns of diversity on a more global scale. The X chromosome is particularly interesting because it contains several distinct regions that are subject to different combinations and strengths of these processes, notably the pseudoautosomal regions (PARs) and the X-transposed region (XTR). The X chromosome thus can serve as a unique model for studying how genetic and demographic forces act in different contexts to shape patterns of observed variation. Here we investigate diversity, divergence, and linkage disequilibrium in each region of the X chromosome using genomic data from 26 human populations. We find that both diversity and substitution rate are consistently elevated in PAR1 and the XTR compared to the rest of the X chromosome. In contrast, linkage disequilibrium is lowest in PAR1 and highest on the non-recombining X chromosome, with the XTR falling in between, suggesting that the XTR (usually included in the non-recombining X) may need to be considered separately in future studies. We also observed strong population-specific effects on genetic diversity; not only does genetic variation differ on the X and autosomes among populations, but the effects of linked selection on the X relative to autosomes have been shaped by population-specific history. The substantial variation in patterns of variation across these regions provides insight into the unique evolutionary history contained within the X chromosome.Significance StatementDemography and selection affect the X chromosome differently from non-sex chromosomes. However, the X chromosome can be subdivided into multiple distinct regions that facilitate even more fine-scaled assessment of these processes. Here we study regions of the human X chromosome in 26 populations to find evidence that recombination may be mutagenic in humans and that the X-transposed region may undergo recombination. Further we observe that the effects of selection and demography act differently on the X chromosome relative to the autosomes across human populations. Together, our results highlight profound regional differences across the X chromosome, simultaneously making it an ideal system for exploring the action of evolutionary forces as well as necessitating its careful consideration and treatment in genomic analyses.


2019 ◽  
Vol 4 ◽  
pp. 25 ◽  
Author(s):  
Cindy S. Chu ◽  
Germana Bancone ◽  
Nay Lin Soe ◽  
Verena I. Carrara ◽  
Gornpan Gornsawun ◽  
...  

Radical cure of Plasmodium vivax malaria in glucose-6-phosphate dehydrogenase (G6PD) deficient individuals employs weekly primaquine dosing. This is the only recommended regimen for this patient sub-group. If national malaria programs mandate daily primaquine dosing (the recommended regimen for G6PD normal individuals), then G6PD testing before prescription is necessary to avoid iatrogenic haemolysis in G6PD deficient individuals. In this case series, two P. vivax infected patients with unknown G6PD status from two different countries were prescribed primaquine as per national malaria program guidelines. During treatment both patients presented to the clinic with symptoms of anaemia after taking primaquine incorrectly. The clinical management of the iatrogenic severe haemolysis that occurred in these patients demonstrates the various adverse effects primaquine can cause, that other common medical treatments also have haemolytic potential, and how the diagnosis of G6PD deficiency can be elusive during acute haemolysis. Health care providers should provide careful instructions about primaquine dosing, be watchful for haemolysis, and have a high index of suspicion for G6PD deficiency in the presence of haemolysis if the G6PD status is previously unknown.


Author(s):  
Julia Evangelista ◽  
William A. Fulford

AbstractThis chapter shows how carnival has been used to counter the impact of Brazil’s colonial history on its asylums and perceptions of madness. Colonisation of Brazil by Portugal in the nineteenth century led to a process of Europeanisation that was associated with dismissal of non-European customs and values as “mad” and sequestration of the poor from the streets into asylums. Bringing together the work of the two authors, the chapter describes through a case study how a carnival project, Loucura Suburbana (Suburban Madness), in which patients in both long- and short-term asylum care play leading roles, has enabled them to “reclaim the streets,” and re-establish their right to the city as valid producers of culture on their own terms. In the process, entrenched stigmas associated with having a history of mental illness in a local community are challenged, and sense of identity and self-confidence can be rebuilt, thus contributing to long-term improvements in mental well-being. Further illustrative materials are available including photographs and video clips.


2019 ◽  
Vol 56 (6) ◽  
pp. 860-875 ◽  
Author(s):  
Michael Palmer ◽  
Cuong Viet Nguyen ◽  
Sophie Mitra ◽  
Daniel Mont ◽  
Nora Ellen Groce

This article investigates the impact of exposure to United States air force bombing during 1965–75 on the disability status of individuals in Vietnam in 2009. Using a combination of national census and US military data and an instrumental variable strategy which exploits the distance to the former North–South border as a quasi-experiment, the article finds a positive and significant impact of bombing exposure on district level disability rates 40 years after the war. The overall effect of bombing on the long-term disability rate among the Vietnamese population is highest among heavily bombed districts. Districts in the top bombing quintile experience a 25% relative increase in the rate of disability attributable to bombing compared with districts in the lowest bombing quintile. Effects are highest on the prevalence of severe disability and among cohorts before the war’s end. A smaller, yet significant, effect is found among cohorts born after the war. The article finds further evidence of indirect channels through which bombing may have impacted on long-term disability including adverse effects on nutritional environment and human capital attainment. These findings add to the evidence from Vietnam and indicate that wars inflict costs on the health of human populations that last longer than those relating to economic growth and welfare.


Heart ◽  
2019 ◽  
Vol 106 (4) ◽  
pp. 299-306
Author(s):  
Tsukasa Kamakura ◽  
Tetsuji Shinohara ◽  
Kenji Yodogawa ◽  
Nobuyuki Murakoshi ◽  
Hiroshi Morita ◽  
...  

ObjectiveLimited data are currently available regarding the long-term prognosis of patients with J-wave syndrome (JWS). The aim of this study was to investigate the long-term prognosis of patients with JWS and identify predictors of the recurrence of ventricular fibrillation (VF).MethodsThis was a multicentre retrospective study (seven Japanese hospitals) involving 134 patients with JWS (Brugada syndrome (BrS): 85; early repolarisation syndrome (ERS): 49) treated with an implantable cardioverter defibrillator. All patients had a history of VF. All patients with ERS underwent drug provocation testing with standard and high intercostal ECG recordings to rule out BrS. The impact of global J waves (type 1 ECG or anterior J waves and inferolateral J waves in two or more leads) on the prognosis was evaluated.ResultsDuring the 91±66 months of the follow-up period, 52 (39%) patients (BrS: 37; ERS: 15) experienced recurrence of VF. Patients with BrS and ERS with global J waves showed a significantly higher incidence of VF recurrence than those without (BrS: log-rank, p=0.014; ERS: log-rank, p=0.0009). The presence of global J waves was a predictor of VF recurrence in patients with JWS (HR: 2.16, 95% CI 1.21 to 3.91, p=0.0095), while previously reported high-risk electrocardiographic parameters (high-amplitude J waves ≥0.2 mV and J waves associated with a horizontal or descending ST segment) were not predictive of VF recurrence.ConclusionsThis multicentre long-term study showed that the presence of global J waves was associated with a higher incidence of VF recurrence in patients with JWS.


2018 ◽  
Vol 47 (1) ◽  
pp. 493-512 ◽  
Author(s):  
Erin P. Riley ◽  
Michelle Bezanson

Field primatologists have ethical responsibilities that extend beyond study subjects to the local human communities living near primate populations and their surrounding ecosystems. In this review, we explore the history of ethical discussions within anthropological primatology and examine the best practices for an ethically engaged primatology that should be followed and role-modeled by primatologists. An increasing number of primates are showing reduced population sizes and are in imminent danger of extinction; thus, we need to carefully consider the ethics of intervening to ensure the survival of remaining populations, the impact of anthropogenic factors (e.g., climate change), and whether long-term field research results in conservation outcomes that consider local human communities. Because best practices change over time as theoretical frameworks and methodological tools advance and scientific goals change, field primatologists must continually reflect on what constitutes ethical practice and consider how research influences the overlapping dimensions of fieldwork: primates, people, and ecosystems.


ARTMargins ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 112-118
Author(s):  
Terry Smith

Change in the history of art has many causes, but one often overlooked by art historical institutions is the complex, unequal set of relationships that subsist between art centers and peripheries. These take many forms, from powerful penetration of peripheral art by the subjects, styles and modes of the relevant center, through accommodation to this penetration to various degrees and kinds of resistance to it. Mapping these relationships should be a major task for art historians, especially those committed to tracing the reception of works of art and the dissemination of ideas about art. This lecture, delivered by Nicos Hadjinicolaou in 1982, outlines a “political art geography” approach to these challenges, and demonstrates it by exploring four settings: the commissioning of paintings commemorating key battles during the Greek War of Independence; the changes in Diego Rivera's style on his return to Mexico from Paris in the 1920s; the impact on certain Mexican artists in the 1960s of “hard edge” painting from the United States; and the differences between Socialist Realism in Moscow and in the Soviet Republics of Asia during the mid-twentieth century. The lecture is here translated into English for the first time and is introduced by Terry Smith, who relates it to its author's long-term art historical quest, as previously pursued in his book Art History and Class Struggle (1973).


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