It’s not all black and white Venables, Stephanie K.; Marshall, Andrea D.; Germanov, Elitza S. ...
Proceedings of the Royal Society. B, Biological sciences,
10/2019, Letnik:
286, Številka:
1912
Journal Article
Recenzirano
Intraspecific colour polymorphisms have been the focus of numerous studies, yet processes affecting melanism in the marine environment remain poorly understood. Arguably, the most prominent example ...of melanism in marine species occurs inmanta rays (Mobula birostris and Mobula alfredi). Here, we use long-term photo identification catalogues to document the frequency variation of melanism across Indo-Pacific manta ray populations and test for evidence of selection by predation acting on colour morph variants. We use mark–recapture modelling to compare survivorship of typical and melanistic colour morphs in three M. alfredi populations and assess the relationship between frequency variation and geographical distance. While therewere large differences in melanism frequencies among populations of both species (0–40.70%), apparent survival estimates revealed no difference in survivorship between colour morphs. We found a significant association between phenotypic and geographical distance in M. birostris, but not in M. alfredi. Our results suggest that melanism is not under selection by predation in the tested M. alfredi populations, and that frequency differences across populations of both species are a consequence of neutral genetic processes. As genetic colour polymorphisms are often subjected to complex selection mechanisms, our findings only begin to elucidate the underlying evolutionary processes responsible for the maintenance and frequency variation of melanism in manta ray populations.
Among patients with hepatitis C virus (HCV) monoinfection, 25-hydroxyvitamin D 25(OH)D concentrations are positively associated with a response to peg-interferon/ribavirin. Data on the relation ...between 25(OH)D concentrations and HCV treatment response in HIV-infected patients are limited.
The objective was to determine whether baseline 25(OH)D concentrations predict virologic response in HIV/HCV co-infected patients and to examine variables associated with 25(OH)D concentrations ≥30 ng/mL.
Data and samples from 144 HCV genotype 1, treatment-naive patients from a completed HCV treatment trial were examined in this retrospective study. Early virologic response (EVR) was defined as ≥2 log10 reduction in HCV RNA and/or HCV RNA <600 IU/mL at week 12 of peg-interferon/ribavirin treatment. Baseline 25(OH)D was measured by liquid chromatography/tandem mass spectrometry.
Compared with the non-EVR control group (n = 68), the EVR group (n = 76) was younger, had fewer cirrhotic subjects, had a higher proportion with the IL28B CC genotype, had a higher albumin concentration, and had a lower HCV viral load at baseline (P ≤ 0.05). The difference in baseline 25(OH)D concentrations between EVR and non-EVR patients was not statistically significant (median: 25 ng/mL compared with 20 ng/mL; P = 0.23). Similar results were found for sustained virologic response (SVR). In multivariable analysis, white and Hispanic race-ethnicity (OR: 6.26; 95% CI: 2.47, 15.88; P = 0.0001) and ritonavir use (OR: 2.68; 95% CI: 1.08, 6.65; P = 0.033) were associated with higher 25(OH)D concentrations (≥30 ng/mL).
Baseline 25(OH)D concentrations did not predict EVR or SVR. Because ritonavir impairs the conversion of 25(OH)D to the active metabolite, utilization of 25(OH)D may have been impaired in subjects taking ritonavir. This trial was registered at www.clinicaltrials.gov as NCT00078403.
Background: Endomyocardial fibrosis (EMF) is the most common form of restrictive
cardiomyopathy worldwide. It has been linked to poverty and various environmental factors,
but—for unknown ...reasons—only some people who live in similar conditions develop the
disease. EMF cases cluster within both families and ethnic groups, suggesting a role for a
genetic factor in host susceptibility. The human leukocyte antigen (HLA) system is associated
with predisposition to various diseases. This two-center study was designed to investigate
variation in the HLA system between EMF patients and unaffected controls. We provide the first
genetic investigation of patients with EMF, as well as a comprehensive review of the literature.
Methods: HLA class I (HLA-A, -B, -C) and class II (DRB1, DQB1) types were determined in 71
patients with severe EMF and 137 controls from Uganda and Mozambique. Chi Square
analysis was used to identify any significant difference in frequency of class I and class II HLA
types between cases and controls.
Results: Compared to ethnically matched controls, HLA-B*58 occurred more frequently in
Mozambique patients with EMF and HLA-A*02:02 occurred more frequently in Ugandan
patients with EMF.
Conclusions: Ample subjective evidence in the historical literature suggests the importance of
a genetically susceptible host in EMF development. In this first formal genetic study, we found
HLA alleles associated with cases of EMF in two populations from sub-Saharan Africa, with
EMF patients being more likely than controls to have the HLA-B*58 allele in Mozambique (p-
0.03) and the HLA-A*02:02 in Uganda (p=0.005) . Further investigations are needed to more
fully understand the role of genetics in EMF development.
Primary biliary cirrhosis (PBC) is generally a slowly progressive disease that may lead to cirrhosis and liver failure. However, patients with PBC often suffer from a variety of symptoms long before ...the development of cirrhosis that include issues of daily living that have an impact on their work environment and their individual quality of life. We therefore examined multiple parameters by taking advantage of the database of our cohort of 1032 patients with PBC and 1041 matched controls. The data were obtained from patients from 23 tertiary referral centers throughout the United States and from rigorously matched controls by age, sex, ethnicity, and random‐digit dialing. The data showed that patients with PBC were more likely than controls to have significant articular symptoms, a reduced ability to perform household chores, and the need for help with routine activities. Patients with PBC rated their overall activity similar or superior to that of controls; however, more of them reported limitations in their ability to carry out activities at work or at home and difficulties in everyday activities. PBC cases also more frequently reported limitations in participating in certain sports or exercises and pursuing various hobbies; however, they did not report significant limitations in social activities. In a multivariable analysis, household income, a diagnosis of systemic lupus erythematosus, limitations in work activities, a reduction in work secondary to disability, and church attendance were independently increased in PBC cases with respect to controls. Conclusion: Our data indicate that the quality of life of patients with PBC in the United States is generally well preserved. Nevertheless, patients with PBC suffer significantly more than controls from a variety of symptoms that are beyond the immediate impact of liver failure and affect their lifestyle, personal relationships, and work activities. (HEPATOLOGY 2008.)
We report the observation and confirmation of the first group- and cluster-scale strong gravitational lensing systems found in Dark Energy Survey data. Through visual inspection of data from the ...Science Verification season, we identified 53 candidate systems. We then obtained spectroscopic follow-up of 21 candidates using the Gemini Multi-object Spectrograph at the Gemini South telescope and the Inamori-Magellan Areal Camera and Spectrograph at the Magellan/Baade telescope. With this follow-up, we confirmed six candidates as gravitational lenses: three of the systems are newly discovered, and the remaining three were previously known. Of the 21 observed candidates, the remaining 15 either were not detected in spectroscopic observations, were observed and did not exhibit continuum emission (or spectral features), or were ruled out as lensing systems. The confirmed sample consists of one group-scale and five galaxy-cluster-scale lenses. The lensed sources range in redshift z~ 0.80-3.2 and in i-band surface brightness i sub(SB)~ 23-25 mag arcsec super(-2)(2'' aperture). For each of the six systems, we estimate the Einstein radius theta sub(E) and the enclosed mass M sub(enc), which have ranges theta sub(E)~ 5''-9'' and M sub(enc)~ 8 x 10 super(12) to 6 x 10 super(13)M sub(middot in circle), respectively.
Background Low vitamin D status has been associated with markers of cardiovascular disease risk. Objective This cross-sectional study assessed the relationships between serum 25-hydroxyvitamin D ...25(OH)D and selected markers for cardiovascular disease risk, including metabolic syndrome and its components, in adult men and women. Methods Fasting blood samples, anthropometric measurements, and blood pressure were assessed in 257 men and women. Dietary intake was assessed with food frequency and dietary supplement questionnaires. Results Total vitamin D intake and that from dietary supplements were significantly associated with increasing serum 25(OH)D tertile (both P < .001). Mean ± SEM serum high-density lipoprotein cholesterol (HDL-C) increased in a graded fashion ( P < .001) from the lowest (48.4 ± 1.8 mg/dL) to the highest (62.3 ± 2.1 mg/dL) 25(OH)D tertile. The relationship between 25(OH)D and HDL-C remained significant ( P < .001) after adjustment for established determinants of the HDL-C, with each 10-ng/mL increase in 25(OH)D associated with a 4.2-mg/dL increase in HDL-C concentration. Serum triglycerides ( P = .008), waist circumference ( P < .001), and body mass index ( P < .001) showed graded, inverse relationships with 25(OH)D tertile, and the prevalence of metabolic syndrome decreased significantly from the lowest to the highest 25(OH)D tertile (31%, 14%, and 10%, respectively, P for trend = .001). Conclusions Lower serum 25(OH)D is associated with the metabolic syndrome and adverse values for some metabolic syndrome risk factors, particularly the HDL-C concentration. Research is warranted to assess whether increasing vitamin D intake will improve the metabolic cardiovascular risk factor profile.
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