149 research outputs found
Learning Counterfactual Representations for Estimating Individual Dose-Response Curves
Estimating what would be an individual's potential response to varying levels
of exposure to a treatment is of high practical relevance for several important
fields, such as healthcare, economics and public policy. However, existing
methods for learning to estimate counterfactual outcomes from observational
data are either focused on estimating average dose-response curves, or limited
to settings with only two treatments that do not have an associated dosage
parameter. Here, we present a novel machine-learning approach towards learning
counterfactual representations for estimating individual dose-response curves
for any number of treatments with continuous dosage parameters with neural
networks. Building on the established potential outcomes framework, we
introduce performance metrics, model selection criteria, model architectures,
and open benchmarks for estimating individual dose-response curves. Our
experiments show that the methods developed in this work set a new
state-of-the-art in estimating individual dose-response
Aortic regurgitation provokes phenotypic modulation of smooth muscle cells in the normal ascending aorta
Background: Aortic complications are more likely to occur in patients with
ascending aortic aneurysms and concomitant aortic regurgitation (AR). AR may
have a negative influence on the aortic wall structure even in patients with tricuspid
aortic valves and absence of aortic dilatation. It is unknown whether smooth muscle
cell (SMC) changes are a feature of AR-associated aortic remodeling.
Methods: Nondilated aortic samples were harvested intraoperatively from individuals with normal aortic valves (n ¼ 10) or those with either predominant aortic stenosis (AS) (n ¼ 20) or AR (n ¼ 35). Tissue from each patient was processed for
immunohistochemistry or used for the extraction of medial SMCs. Tissue and cells
were stained for markers of SMC contraction (alpha-smooth muscle actin), synthesis (vimentin) and senescence (p16INK4A and p21Cip1 [p16/p21]). Replicative capacity
was analyzed in cultured SMCs from AS- and AR-associated aortas. A subanalysis
compared SMCs from individuals with either tricuspid aortic valves or bicuspid
aortic valves to evaluate the effect of aortic valve morphology.
Results: In aortic tissue samples, AR was associated with decreased alpha-smooth
muscle actin and increased vimentin, p16 and p21 compared with normal aortic
valves and AS. In cell culture, SMCs from AR-aortas had decreased alpha-smooth
muscle actin and increased vimentin compared with SMCs from AS-aortas. ARassociated SMCs had increased p16 and p21 expression, and they reached
senescence earlier than SMCs from AS-aortas. In AR, SMC changes were more
pronounced with the presence of a bicuspid aortic valve.
Conclusions: AR itself negatively influences SMC phenotype in the ascending aortic
wall. This AR-specific effect is independent of aortic diameter and aortic valve
morphology, although it is more pronounced with bicuspid aortic valves. These
findings provide insight into the mechanisms of AR-related aortic remodeling,
and they provide a model for studying SMC-specific therapies in culture. (J Thorac
Cardiovasc Surg 2023;166:1604-16
Age-dependent phenotypic modulation of smooth muscle cells in the normal ascending aorta
Objectives: Ascending aortic aneurysms are associated with pre-existing conditions,
including connective tissue disorders (i.e., Marfan syndrome) and bicuspid aortic
valves. The underlying mechanisms remain uncertain. Even less is known regarding
ascending aortic aneurysms in individuals with normal (i.e., tricuspid) aortic valves
(TAV), and without known aneurysm-associated disorders. Regardless of etiology, the
risk of aortic complications increases with biological age. Phenotypic modulation of
smooth muscle cells (SMCs) is a feature of ascending aortic aneurysms, whereby
contractile SMCs are replaced with synthetic SMCs that are capable of degrading
the aortic wall. We asked whether age itself causes dysfunctional SMC phenotype
modulation, independent of aortic dilatation or pre-existing aneurysm-associated
diseases.
Methods: Non-dilated ascending aortic samples were obtained intra-operatively
from 40 patients undergoing aortic valve surgery (range: 20–82 years old, mean:
59.1 ± 15.2). Patients with known genetic diseases or aortic valve malformations were
excluded. Tissue was divided, and a portion was formalin-fixed and immunolabeled
for alpha-smooth muscle actin (ASMA), a contractile SMC protein, and markers of
synthetic (vimentin) or senescent (p16/p21) SMCs. Another fragment was used for
SMC isolation (n = 10). Cultured SMCs were fixed at cell passage 2 and stained for
phenotype markers, or were cultured indefinitely to determine replicative capacity.
Results: In whole tissue, ASMA decreased (R2 = 0.47, P < 0.0001), while vimentin
increased (R2 = 0.33, P = 0.02) with age. In cultured SMCs, ASMA decreased
(R2 = 0.35, P = 0.03) and vimentin increased (R2 = 0.25, P = 0.04) with age. p16
(R2 = 0.34, P = 0.02) and p21 (R2 = 0.29, P = 0.007) also increased with age in SMCs.
Furthermore, the replicative capacity of SMCs from older patients was decreased
compared to that of younger patients (P = 0.03).
Conclusion: By investigating non-dilated aortic samples from individuals with normal
TAVs, we found that age itself has a negative impact on SMCs in the ascending
aortic wall, whereby SMCs switched from the contractile phenotype to maladaptive
synthetic or senescent states with increased age. Therefore, based on our findings,
modification of SMC phenotype should be studied as a therapeutic consideration
against aneurysms in the future, regardless of etiology
SMAD3 contributes to ascending aortic dilatation independent of transforming growth factor-beta in bicuspid and unicuspid aortic valve disease
We sought to determine whether there are differences in transforming growth factor-beta (TGFß) signaling in aneurysms associated with bicuspid (BAV) and unicuspid (UAV) aortic valves versus normal aortic valves. Ascending aortic aneurysms are frequently associated with BAV and UAV. The mechanisms are not yet clearly defined, but similarities to transforming growth factor-beta TGFß vasculopathies (i.e. Marfan, Loeys-Dietz syndromes) are reported. Non-dilated (ND) and aneurysmal (D) ascending aortic tissue was collected intra-operatively from individuals with a TAV (N = 10ND, 10D), BAV (N = 7ND, 8D) or UAV (N = 7ND, 8D). TGFß signaling and aortic remodeling were assessed through immuno-assays and histological analyses. TGFß1 was increased in BAV/UAV-ND aortas versus TAV (P = 0.02 and 0.04, respectively). Interestingly, TGFß1 increased with dilatation in TAV (P = 0.03) and decreased in BAV/UAV (P = 0.001). In TAV, SMAD2 and SMAD3 phosphorylation (pSMAD2, pSMAD3) increased with dilatation (all P = 0.04) and with TGFß1 concentration (P = 0.04 and 0.03). No relationship between TGFß1 and pSMAD2 or pSMAD3 was observed for BAV/UAV (all P > 0.05). pSMAD3 increased with dilatation in BAV/UAV aortas (P = 0.01), whereas no relationship with pSMAD2 was observed (P = 0.56). Elastin breaks increased with dilatation in all groups (all P < 0.05). In TAV, elastin degradation correlated with TGFß1, pSMAD2 and pSMAD3 (all P < 0.05), whereas in BAV and UAV aortas, elastin degradation correlated only with pSMAD3 (P = 0.0007). TGFß signaling through SMAD2/SMAD3 contributes to aortic remodeling in TAV, whereas TGFß-independent activation of SMAD3 may underlie aneurysm formation in BAV/UAV aortas. Therefore, SMAD3 should be further investigated as a therapeutic target against ascending aortic dilatation in general, and particularly in BAV/UAV patients
Проект планировки и межевания территории квартала в производственно-деловой зоне г. Томска
Подготовка проекта межевания осуществляется применительно к территории, расположенной в границах элемента планировочной структуры – нежилого квартала, ограниченного проспектом Кирова, улицами Киевская, Усова, Артёма. Границы квартала определены генеральным планом города Томска, а также правилами землепользования и застройки города Томска. Проект межевания квартала подготавливается на основе проекта планировки данной территории в целях установления границ земельных участков и содержит графическую и текстовую части. Основанием для подготовки проекта межевания является постановление администрации Города Томска от 27.03.2017 г. №275-з.The boundary-setting plan is developed to the Tomsk’s non-residental quarter. An element of planning structure has its borders submitted by Kirova avenue, Kievskaya, Usova and Artyoma streets. Borders of quarter are defined by the city master plan and rules of land use and building of the city of Tomsk. The boundary-setting plan of quarter is prepared on the basis of the draft area plan of this territory for the purpose of land parcels borders establishment. The project consists of a graphic part and the text explanation. The basis for preparation of the project is the resolution of city administration of Tomsk
Anaerobutyricum hallii promotes the functional depletion of a food carcinogen in diverse healthy fecal microbiota
IntroductionAnaerobutyricum hallii is a human gut commensal that transforms the heterocyclic amine 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP), a carcinogen from cooked meat. The transformation mechanism involves the microbial production of acrolein from glycerol, and its conjugation with PhIP, thus blocking its mutagenic potential. A potential cancer prevention strategy could therefore involve supplementing complex human microbial communities with metabolically competent bacteria such as A. hallii that can deplete PhIP. However, it has not been established how the proportion of A. hallii in diverse healthy human gut microbial communities relates to functional capacity for PhIP transformation and, moreover, how supplementing microbiomes with A. hallii affects this function.MethodsIn this study, shotgun metagenomics was used to study taxonomic profiling, the abundance of glycerol/diol dehydratase (gdh)-harboring taxa, the proportion of resident A. hallii, and the reconstruction of A. hallii population genomes in the fecal samples of 20 healthy young adult donors. Furthermore, the influence of supplementing 106 cells/mL of A. hallii DSM 3353 with diluted fecal microbiota was characterized.Results and discussionSix microbiota were assigned to Bacteroides, nine to Prevotella, and five to Ruminococcus by enterotype-associated clustering. The total number of gdh copies in the 20 fecal microbiota expressed per 1010 bacterial cells ranged between 1.32 × 108 and 1.15 × 109. Eighteen out of the 20 donors were dominated by A. hallii, representing between 33% and 94% of the total gdh relative abundance of the samples. The microbiota with low A. hallii abundance (i.e., with a relative abundance < 1%) transformed less PhIP than the microbiota with high A. hallii abundance (i.e., with a relative abundance > 1%). Furthermore, supplementing the low-A. hallii-abundant microbiota with glycerol significantly increased the PhIP transformation capacity after 6 h while reducing total short-chain fatty acid (SCFA) levels, which is most likely due to acrolein production. Although acetate decreased in all microbiota with glycerol and with the combination of glycerol and A. hallii, for most of the microbiomes, butyrate production increased over time. Thus, for a significant number of diverse healthy human fecal microbiomes, and especially when they have little of the taxa to start with, supplementing A. hallii increases PhIP transformation. These findings suggest the need to test in vivo whether supplementing microbiomes with A. hallii reduces PhIP exposure
DAOA/G72 predicts the progression of prodromal syndromes to first episode psychosis
The genetic factors determining the progression of prodromal syndromes to first episode schizophrenia have remained enigmatic to date. In a unique prospective multicentre trial, we assessed whether variants at the d-amino acid oxidase activator (DAOA)/G72 locus influence progression to psychosis. Young subjects with a prodromal syndrome were observed prospectively for up to 2 years to assess the incidence of progression to schizophrenia or first episode psychosis. Of the 82 probands with a prodromal syndrome, 21 probands experienced progression to psychosis within the observation period. Assessment of nine common variants in the DAOA/G72 locus yielded two variants with the predictive value for symptom progression: all four probands with the rs1341402 CC genotype developed psychosis compared with 17 out of 78 probands with the TT or CT genotypes (χ2 = 12.348; df = 2; p = 0.002). The relative risk for progression to psychosis was significantly increased in the CC genotype: RR = 4.588 (95% CI = 2.175–4.588). Similarly, for rs778294, 50% of probands with the AA genotype, but only 22% of probands with a GG or GA genotype progressed to psychosis (χ2 = 7.027; df = 2; p = 0.030). Moreover, haplotype analysis revealed a susceptibility haplotype for progression to psychosis. This is one of the first studies to identify a specific genetic factor for the progression of prodromal syndromes to schizophrenia, and further underscores the importance of the DAOA/G72 gene for schizophrenia
Subjective and Objective Olfactory Abnormalities in Crohn’s disease
The pathogenesis of Crohn’s disease (CD) is still unknown, but the involvement of the olfactory system in CD appears possible. No study to date has systematically assessed the olfactory function in CD patients. We investigated the olfactory function in CD patients in active (n = 31) and inactive disease (n = 27) and in a control group of age- and sex-matched healthy subjects (n = 35). Subjective olfactory testing was applied using the Sniffin’ Sticks test. For olfactory testing, olfactory event–related potentials (OERPs) were obtained with a 4-channel olfactometer using phenyl ethyl alcohol (PEA) and hydrogen sulfide (H2S). Carbon dioxide (CO2) was employed as control stimulus, and chemosomatosensory event–related potentials (CSSERPs) were registered. Results of the Sniffin’ Sticks test revealed significantly different olfactory hedonic judgment with increased olfactory hedonic estimates for pleasant odorants in CD patients in active disease compared with healthy subjects. A statistical trend was found toward lower olfactory thresholds in CD patients. In objective olfactory testing, CD patients showed lower amplitudes of OERPs and CSSERPs. Additionally, OERPs showed significantly shorter N1- and P2 latencies following stimulation of the right nostril with H2S in CD patients in inactive disease compared with controls. Our study demonstrates specific abnormalities of olfactory perception in CD patients
Predictors of transient congenital primary hypothyroidism: data from the German registry for congenital hypothyroidism (AQUAPE “HypoDok”)
Neonatal screening for congenital primary hypothyroidism (CH) may not distinguish between transient (TCH) and permanent dysfunction (PCH), causing potential overtreatment and concerns in affected families. To specify the indication for interruption of therapy, we analysed the German registry “HypoDok” for infants with CH, which oversees 1625 patients from 49 participating centres in Germany and Austria from 1997 until today. A total of 357 patients with a thyroid gland in loco typico were identified and retrospectively grouped according to cessation (TCH, n = 24) or continuation (PCH, n = 333) of l-thyroxine (l-T4) treatment at 2 years of age. The receiver operating characteristic (ROC) analysis was performed to identify cutoffs predicting TCH by screening TSH concentrations and l-T4 dosages. Gestational ages, birth weights and prevalence of associated malformations were comparable in both groups. The cutoff screening TSH concentration was 73 mU/L. The cutoff daily l-T4 dosage at 1 year was 3.1 μg/kg (90% sensitivity, 63% specificity; 36 μg/day) and at 2 years of age 2.95 μg/kg (91% sensitivity, 59% specificity; 40 μg/day). At 2 years of age, specificity (71%) increased when both of these parameters were considered together.
Conclusion: The decision to continue or cease l-T4 treatment at 2 years of age in CH patients diagnosed in neonatal screening may be based on their screening TSH concentrations and individual l-T4 dosages at 1 and 2 years of age. Thus, TCH and PCH may be distinguished; overtreatment avoided; and affected families reassured
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