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1.
Respir Res ; 25(1): 142, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38528524

ABSTRACT

BACKGROUND: The underlying pathophysiological pathways how reverse triggering is being caused are not fully understood. Respiratory entrainment may be one of these mechanisms, but both terms are used interchangeably. We sought to characterize reverse triggering and the relationship with respiratory entrainment among mechanically ventilated children with and without acute lung injury. METHODS: We performed a secondary phyiology analysis of two previously published data sets of invasively mechanically ventilated children < 18 years with and without lung injury mechanically ventilated in a continuous or intermittent mandatory ventilation mode. Ventilator waveforms, electrical activity of the diaphragm measured with surface electromyography and oesophageal tracings were analyzed for entrained and non-entrained reverse triggered breaths. RESULTS: In total 102 measurements (3110 min) from 67 patients (median age 4.9 [1.8 ; 19,1] months) were analyzed. Entrained RT was identified in 12 (12%) and non-entrained RT in 39 (38%) recordings. Breathing variability for entrained RT breaths was lower compared to non-entrained RT breaths. We did not observe breath stacking during entrained RT. Double triggering often occurred during non-entrained RT and led to an increased tidal volume. Patients with respiratory entrainment related RT had a shorter duration of MV and length of PICU stay. CONCLUSIONS: Reverse triggering is not one entity but a clinical spectrum with different mechanisms and consequences. TRIAL REGISTRATION: Not applicable.


Subject(s)
Acute Lung Injury , Respiration, Artificial , Child , Humans , Child, Preschool , Respiration, Artificial/adverse effects , Prospective Studies , Respiration , Ventilators, Mechanical
2.
Entropy (Basel) ; 26(2)2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38392378

ABSTRACT

Quantum-key-distribution (QKD) networks are gaining importance and it has become necessary to analyze the most appropriate methods for their long-distance interconnection. In this paper, four different methods of interconnecting remote QKD networks are proposed. The methods are used to link three different QKD testbeds in Europe, located in Berlin, Madrid, and Poznan. Although long-distance QKD links are only emulated, the methods used can serve as a blueprint for the secure interconnection of distant QKD networks in the future. Specifically, the presented approaches combine, in a transparent way, different fiber and satellite physical media, as well as common standards of key delivery interfaces. The testbed interconnections are designed to increase the security by utilizing multipath techniques and multiple hybridizations of QKD and post-quantum cryptography (PQC) algorithms.

3.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Article in English | MEDLINE | ID: mdl-38065183

ABSTRACT

We sympathetically cool highly charged ions (HCI) in Coulomb crystals of Doppler-cooled Be+ ions confined in a cryogenic linear Paul trap that is integrated into a fully enclosing radio-frequency resonator manufactured from superconducting niobium. By preparing a single Be+ cooling ion and a single HCI, quantum logic spectroscopy toward frequency metrology and qubit operations with a great variety of species are enabled. While cooling down the assembly through its transition temperature into the superconducting state, an applied quantization magnetic field becomes persistent, and the trap becomes shielded from subsequent external electromagnetic fluctuations. Using a magnetically sensitive hyperfine transition of Be+ as a qubit, we measure the fractional decay rate of the stored magnetic field to be at the 10-10 s-1 level. Ramsey interferometry and spin-echo measurements yield coherence times of >400 ms, demonstrating excellent passive magnetic shielding at frequencies down to DC.

4.
Sensors (Basel) ; 23(10)2023 May 09.
Article in English | MEDLINE | ID: mdl-37430507

ABSTRACT

This paper presents novel current sensorless maximum-power point-tracking (MPPT) algorithms based on compensators/controllers and a single-input voltage sensor. The proposed MPPTs eliminate the expensive and noisy current sensor, which can significantly reduce the system cost and retain the advantages of the widely used MPPT algorithms, such as Incremental Conductance (IC) and Perturb and Observe (P&O) algorithms. Additionally, it is verified that the proposed algorithms, especially the proposed Current Sensorless V based on PI, can reach outstanding tracking factors (TFs) such as the IC and P&O based on PI algorithms. In this sense, the insertion of controllers inside the MPPT gives them adaptive characteristics, and the experimental TFs are in the remarkable range of more than 99%, with an average yield of 99.51% and a peak of 99.80%.

5.
Front Plant Sci ; 14: 1135047, 2023.
Article in English | MEDLINE | ID: mdl-37275249

ABSTRACT

An efficient genetic transformation protocol is necessary to edit genes for trait improvement directly in elite bread wheat cultivars. We used a protein fusion between a wheat growth-regulating factor 4 (GRF4) and its interacting factor (GIF1) to develop a reproducible genetic transformation and regeneration protocol, which we then used to successfully transform elite bread wheat cultivars Baj, Kachu, Morocco, Reedling, RL6077, and Sujata in addition to the experimental cultivar Fielder. Immature embryos were transformed with the vector using particle bombardment method. Transformation frequency increased nearly 60-fold with the GRF4-GIF1-containing vectors as compared to the control vector and ranged from ~5% in the cultivar Kachu to 13% in the cultivar RL6077. We then edited two genes that confer resistance against leaf rust and powdery mildew directly in the aforementioned elite cultivars. A wheat promoter, TaU3 or TaU6, to drive the expression of guide RNA was effective in gene editing whereas the OsU3 promoter failed to generate any edits. Editing efficiency was nearly perfect with the wheat promoters. Our protocol has made it possible to edit genes directly in elite wheat cultivars and would be useful for gene editing in other wheat varieties, which have been recalcitrant to transformation thus far.

6.
Materials (Basel) ; 16(10)2023 May 12.
Article in English | MEDLINE | ID: mdl-37241316

ABSTRACT

A polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide. The dipeptide is known to show molecular flexibility in different environments, which leads to polymorphism. The crystal structure of the glycyl-L-alanine HI.H2O polymorph is determined at room temperature and indicates that the space group is polar (P21), with two molecules per unit cell and unit cell parameters a = 7.747 Å, b = 6.435 Å, c = 10.941 Å, α = 90°, ß = 107.53(3)°, γ = 90° and V = 520.1(7) Å3. Crystallization in the polar point group 2, with one polar axis parallel to the b axis, allows pyroelectricity and optical second harmonic generation. Thermal melting of the glycyl-L-alanine HI.H2O polymorph starts at 533 K, close to the melting temperature reported for cyclo-glycyl-L-alanine (531 K) and 32 K lower than that reported for linear glycyl-L-alanine dipeptide (563 K), suggesting that although the dipeptide, when crystallized in the polymorphic form, is not anymore in its cyclic form, it keeps a memory of its initial closed chain and therefore shows a thermal memory effect. Here, we report a pyroelectric coefficient as high as 45 µC/m2K occurring at 345 K, one order of magnitude smaller than that of semi-organic ferroelectric triglycine sulphate (TGS) crystal. Moreover, the glycyl-L-alanine HI.H2O polymorph displays a nonlinear optical effective coefficient of 0.14 pm/V, around 14 times smaller than the value from a phase-matched inorganic barium borate (BBO) single crystal. The new polymorph displays an effective piezoelectric coefficient equal to deff=280 pCN-1, when embedded into electrospun polymer fibers, indicating its suitability as an active system for energy harvesting.

7.
HPB (Oxford) ; 24(10): 1711-1719, 2022 10.
Article in English | MEDLINE | ID: mdl-35550727

ABSTRACT

BACKGROUND: Sarcopenia is associated with impaired short- and long-term outcomes in gastrointestinal cancers. Whether sarcopenia is associated with impaired survival after local therapy of Colorectal Cancer Liver Metastases (CRLM) remains controversial. This study aimed to determine the influence of sarcopenia on long-term outcomes after curative-intent therapy for CRLM. METHODS: Patients undergoing local therapy for CRLM between 2003 and 2019 were retrospectively analyzed using the skeletal muscle index at the level of the third lumbar vertebra as an indicator of sarcopenia. Factors associated with overall (OS) and disease-free (DFS) survival were analyzed using univariable and multivariable cox regression. RESULTS: In total 213/465 patients (46%) were considered sarcopenic. Sarcopenic patients had no impaired 5-year OS or DFS compared to non-sarcopenic patients, 38% vs 44% (p = 0.153) and 19 vs 23% (p = 0.339) respectively. Sarcopenia was not associated with impaired OS (HR = 1.11, 95%CI = 0.85-1.46, p = 0.43) or DFS (HR = 0.99, 95%CI = 0.77-1.28, p = 0.96) in multivariable analysis. There were no significant differences in postoperative complications (p = 0.47), the incidence (p = 0.65) and treatment (p = 0.37) of recurrent metastases. Five-year OS after resection for recurrences was 14% (sarcopenic) and 22% (non-sarcopenic) p 0.716. CONCLUSION: Sarcopenia assessed by computed tomography was not associated with impaired survival outcomes in the group of CRLM patients overall.


Subject(s)
Colorectal Neoplasms , Liver Neoplasms , Sarcopenia , Humans , Retrospective Studies , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/surgery , Sarcopenia/diagnostic imaging , Sarcopenia/complications , Muscle, Skeletal/diagnostic imaging , Tomography, X-Ray Computed , Colorectal Neoplasms/pathology , Prognosis
8.
Am Heart J ; 243: 187-200, 2022 01.
Article in English | MEDLINE | ID: mdl-34582775

ABSTRACT

BACKGROUND: The ISCHEMIA-CKD (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches-Chronic Kidney Disease) trial found no advantage to an invasive strategy compared to conservative management in reducing all-cause death or myocardial infarction (D/MI). However, the prognostic influence of angiographic coronary artery disease (CAD) burden and ischemia severity remains unknown in this population. We compared the relative impact of CAD extent and severity of myocardial ischemia on D/MI in patients with advanced chronic kidney disease (CKD). METHODS: Participants randomized to invasive management with available data on coronary angiography and stress testing were included. Extent of CAD was defined by the number of major epicardial vessels with ≥50% diameter stenosis by quantitative coronary angiography. Ischemia severity was assessed by site investigators as moderate or severe using trial definitions. The primary endpoint was D/MI. RESULTS: Of the 388 participants, 307 (79.1%) had complete coronary angiography and stress testing data. D/MI occurred in 104/307 participants (33.9%). Extent of CAD was associated with an increased risk of D/MI (P < .001), while ischemia severity was not (P = .249). These relationships persisted following multivariable adjustment. Using 0-vessel disease (VD) as reference, the adjusted hazard ratio (HR) for 1VD was 1.86, 95% confidence interval (CI) 0.94 to 3.68, P = .073; 2VD: HR 2.13, 95% CI 1.10 to 4.12, P = .025; 3VD: HR 4.00, 95% CI 2.06 to 7.76, P < .001. Using moderate ischemia as the reference, the HR for severe ischemia was 0.84, 95% CI 0.54 to 1.30, P = .427. CONCLUSION: Among ISCHEMIA-CKD participants randomized to the invasive strategy, extent of CAD predicted D/MI whereas severity of ischemia did not.


Subject(s)
Coronary Artery Disease , Myocardial Ischemia , Renal Insufficiency, Chronic , Coronary Angiography , Coronary Artery Disease/complications , Coronary Artery Disease/diagnosis , Coronary Artery Disease/epidemiology , Humans , Ischemia/complications , Myocardial Ischemia/complications , Myocardial Ischemia/epidemiology , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/epidemiology , Risk Factors
9.
HPB (Oxford) ; 24(1): 9-16, 2022 01.
Article in English | MEDLINE | ID: mdl-34556406

ABSTRACT

BACKGROUND: Sarcopenia is defined as either low pre-operative muscle mass or low muscle density on abdominal CT imaging. It has been associated with worse short-term outcomes after surgery for colorectal liver metastases. This study aimed to evaluate whether sarcopenia also impacts long-term survival outcomes in these patients. METHODS: A random-effects meta-analysis was conducted following the PRISMA guidelines. Overall survival (OS) and disease-free survival (DFS) outcomes were evaluated. RESULTS: Eleven studies were included, ten reporting on the impact of low muscle mass and four on low muscle density. Sample sizes ranged between 47 and 539 (2124 patients in total). Altogether, 897 (42%) patients were considered sarcopenic, although definitions varied between studies. Median follow-up was 21-74 months. Low muscle mass (hazard ration (HR) 1.35, 95%CI 1.08-1.68) and low muscle density (HR 1.97, 95%CI 1.07-3.62) were associated with impaired OS. Low muscle mass (pooled HR 1.17, 95%CI 0.94-1.46) and low muscle density (pooled HR 1.13, 95%CI 0.85-1.50) were not associated with impaired RFS. DISCUSSION: Sarcopenia is associated with poorer OS, but not RFS, in patients with CRLM. Additional studies with standardized sarcopenia definitions are needed to better assess the impact of sarcopenia in patients with CRLM.


Subject(s)
Colorectal Neoplasms , Liver Neoplasms , Sarcopenia , Colorectal Neoplasms/pathology , Disease-Free Survival , Humans , Liver Neoplasms/complications , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/surgery , Prognosis , Progression-Free Survival , Sarcopenia/complications , Sarcopenia/etiology
10.
Angew Chem Int Ed Engl ; 60(10): 5482-5488, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33245820

ABSTRACT

Described here is a titanocene-catalyzed reaction for the synthesis of acetals and hemiaminals from benzylic ethers and benzylic amines, respectively, with pendant epoxides. The reaction proceeds by catalysis in single-electron steps. The oxidative addition comprises an epoxide opening. An H-atom transfer, to generate a benzylic radical, serves as a radical translocation step, and an organometallic oxygen rebound as a reductive elimination. The reaction mechanism was studied by high-level dispersion corrected hybrid functional DFT with implicit solvation. The low-energy conformational space was searched by the efficient CREST program. The stereoselectivity was deduced from the lowest lying benzylic radical structures and their conformations are controlled by hyperconjugative interactions and steric interactions between the titanocene catalyst and the aryl groups of the substrate. An interesting mechanistic aspect is that the oxidation of the benzylic center occurs under reducing conditions.

11.
Clin Breast Cancer ; 20(5): 377-381, 2020 10.
Article in English | MEDLINE | ID: mdl-32402812

ABSTRACT

BACKGROUND: Breast cancer screening has been shown to reduce breast cancer-associated mortality. However, screening is limited to the targeted age group of 45 to 69 years in New Zealand despite the recognized increased risk with age. This study aims to compare the outcomes of women aged over 70 years with screen-detected and clinically detected cancers. PATIENTS AND METHODS: A retrospective review was performed of prospectively collected data from June 2000 to May 2013 by the Auckland Breast Cancer Register. Demographic and tumor characteristics of women with invasive cancer and ductal carcinoma in situ diagnosis aged 70 years and over were compared between those screened and clinically detected. Five-year disease-free and overall survival outcomes were reviewed. RESULTS: A total of 2128 women aged 70 years and over were diagnosed with breast cancer (median, 77 years; interquartile range [IQR], 74-84 years). Of these, 416 (19.5%) were diagnosed through mammography screening, with a median age of 74 years (IQR, 71-77 years) compared with 79 years (IQR, 74-85 years) for those with clinical detected cancer diagnosis. Screen-detected cancers accounted for a significantly higher proportion of diagnoses in those aged 70 to 74 years compared with older patients (P < .001). Screen-detected cancers were of lower T and N stages. Disease-specific survival was significantly longer in screen-detected cancers versus other cancers (5-year survival, 93.7% vs. 81.9%; P < .001), as was overall survival (5-year survival, 84.7% vs. 57.4%; P < .001). CONCLUSION: Screening in those aged 70 years and over continues to identify breast cancer at early stages and with improved survival. Although aware of the potential for lead-time bias and the healthy volunteer effect, there should still be consideration to extend breast cancer screening to patients aged to up 74 years after appropriate assessment of comorbidities and functional status.


Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , Age Factors , Aged , Aged, 80 and over , Breast Neoplasms/diagnostic imaging , Early Detection of Cancer/methods , Female , Humans , Mammography/methods , New Zealand/epidemiology , Retrospective Studies
12.
Can J Diabetes ; 44(7): 624-627, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32178973

ABSTRACT

OBJECTIVES: In this work, we describe diabetes prevalence and birth outcomes in a primarily First Nations obstetrical population in northwest Ontario. METHODS: This retrospective, observational study of maternal and neonatal characteristics and birth outcomes was performed at the Sioux Lookout Meno Ya Win Health Centre between April 1, 2012 and March 31, 2017. RESULTS: The prevalence of pre-existing type 2 diabetes mellitus was 3.7% and gestational diabetes mellitus was 7.9%. Mothers with diabetes, compared to those without diabetes, were, on average, 5 years older and were of greater parity. Average prepregnancy weight was higher, with an increased incidence of hypertension, inductions and caesarean sections. Neonates had increased incidence of macrosomia, hypoglycemia and hyperbilirubinemia. All maternal cohorts had high rates of alcohol, tobacco and illicit opioid use. CONCLUSIONS: We have identified a high prevalence of diabetes in this First Nations obstetrical population, with associated adverse maternal and neonatal outcomes.


Subject(s)
Cesarean Section/methods , Diabetes Mellitus, Type 2/physiopathology , Diabetes, Gestational/epidemiology , Pregnancy Complications/epidemiology , Adult , Biomarkers/analysis , Female , Follow-Up Studies , Humans , Ontario/epidemiology , Pregnancy , Prognosis , Retrospective Studies , Young Adult
13.
FEBS J ; 287(20): 4401-4414, 2020 10.
Article in English | MEDLINE | ID: mdl-32096906

ABSTRACT

Yeast amino acid transporters of the APC superfamily are responsible for the proton motive force-driven uptake of amino acids into the cell, which for most secondary transporters is a reversible process. The l-lysine proton symporter Lyp1 of Saccharomyces cerevisiae is special in that the Michaelis constant from out-to-in transport ( Kmout→in ) is much lower than Kmin→out , which allows accumulation of l-lysine to submolar concentration. It has been proposed that high intracellular lysine is part of the antioxidant mechanism of the cell. The molecular basis for the unique kinetic properties of Lyp1 is unknown. We compared the sequence of Lyp1 with APC para- and orthologues and find structural features that set Lyp1 apart, including differences in extracellular loop regions. We screened the extracellular loops by alanine mutagenesis and determined Lyp1 localization and activity and find positions that affect either the localization or activity of Lyp1. Half of the affected mutants are located in the extension of extracellular loop 3 or in a predicted α-helix in extracellular loop 4. Our data indicate that extracellular loops not only connect the transmembrane helices but also serve functionally important roles.


Subject(s)
Amino Acid Transport Systems, Basic/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/metabolism , Amino Acid Transport Systems, Basic/analysis , Amino Acid Transport Systems, Basic/genetics , Computational Biology , Kinetics , Lysine/metabolism , Models, Molecular , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae Proteins/analysis , Saccharomyces cerevisiae Proteins/genetics
14.
Q J R Meteorol Soc ; 145(723): 2817-2834, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31588152

ABSTRACT

The Netherlands is characterized by highly variable land use within a small area, and a strong influence of the North Sea on national climate. Devoid of significant topography, it is an excellent location for assessing the relative influence of various factors on fog occurrence in the absence of terrain effects. Using observations from a dense network of weather stations throughout the country, the climatology of fog in the Netherlands is assessed over a period of 45 years. On a national scale, interannual variability is linked to changes in synoptic pressure-gradient forcing. Within the country, a comprehensive in-depth analysis of regional differences between fog occurrence is made, together with an assessment of local physical factors which could bias fog formation in one location over another. Regional variability is shown to be strongly related to the mesoscale influences of urbanization and the North Sea. In fact, some locations experience over twice as much fog as others. From this finding, a simple index is presented, which combines the water and urban fraction surrounding a station. This "Regionally Weighted Index" (RWI) is able to accurately sort the stations according to their relative fogginess. Its practical use is encouraged for assessing a given site's climatological favourability, even when in situ meteorological observations are unavailable.

15.
Aesthet Surg J ; 38(10): NP152, 2018 09 14.
Article in English | MEDLINE | ID: mdl-30032168
16.
Chemistry ; 24(24): 6371-6379, 2018 Apr 25.
Article in English | MEDLINE | ID: mdl-29327511

ABSTRACT

We present a combined electrochemical, kinetic, and synthetic study with a novel and easily accessible class of titanocene catalysts for catalysis in single-electron steps. The tailoring of the electronic properties of our Cp2 TiX-catalysts that are prepared in situ from readily available Cp2 TiX2 is achieved by varying the anionic ligand X. Of the complexes investigated, Cp2 TiOMs proved to be either equal or substantially superior to the best catalysts developed earlier. The kinetic and thermodynamic properties pertinent to catalysis have been determined. They allow a mechanistic understanding of the subtle interplay of properties required for an efficient oxidative addition and reduction. Therefore, our study highlights that efficient catalysts do not require the elaborate covalent modification of the cyclopentadienyl ligands.

17.
J Eur Acad Dermatol Venereol ; 32(3): 495-501, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29178539

ABSTRACT

BACKGROUND: More than 20 years ago, our reappraisal of the Hutchinson's sign (HS) gave birth to the concept of the pseudo-Hutchinson's sign. OBJECTIVES: We have found it interesting to emphasize some important histologic points and to expand the list of the numerous HS simulants. METHODS: We have examined the cutaneous samples taken from the pigmented skin of patients in association with nail matrix biopsy. We have also extended the long list of non-melanoma HS based on comprehensive literature review. RESULTS: Histologically, HS may present only as an epidermal pigmentation, depending on the area sampled. Occasionally, there may be a sparse junctional melanocytic proliferation which does not demonstrate cytologic atypia due to an underlying melanocytic naevus of the nail matrix. However, early HS often shows a melanoma in situ, with a HS at the proximal nail fold (PNF) and confluent "atypical" melanocytes in the nail matrix. Finally, involvement of the PNF, nail matrix and nail bed containing atypical melanocytes in irregular array may be seen in more advanced lesions. The recent literature on non-melanoma HS simulants is summarized and clinical examples are provided. CONCLUSION: The mere presence of periungual pigmentation is neither clinically nor histologically pathognomonic of subungual melanoma and justifies the usefulness of this work stressing the non-melanoma HS.


Subject(s)
Nail Diseases/pathology , Nails/pathology , Skin Neoplasms/pathology , Biopsy , Cell Proliferation , Diagnosis, Differential , Humans , Melanocytes/pathology , Nail Diseases/diagnosis , Skin Neoplasms/diagnosis , Skin Pigmentation
18.
Alcohol Alcohol ; 51(4): 457-64, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26818195

ABSTRACT

AIM: To determine the detection rates, clinical features, and risk factors for lack of registration of alcohol use in medical patients admitted in European hospitals. METHODS: A point-prevalence, cross-sectional, multicenter survey involving 2100 medical inpatients from 43 hospitals from 8 European countries. Patients were screened for current alcohol use, using standardized questionnaires. Alcohol use recording in medical records was assessed. RESULTS: Of the 2100, more than a half reported alcohol use. Significant differences were shown in the prevalence of drinking and the recording rates of alcohol use among the hospitals and countries involved. Overall, 346 patients (16%) fulfilled criteria for alcohol use disorder. Alcohol use was registered in 909 (43%) of medical records, with quantification in 143 (7%). Multivariate analysis showed that women (OR 1.49), older age patients (OR 1.23), patients from the Northern European countries (OR 4.79) and from hospitals with high local alcohol prevalence (OR 1.59) were more likely to have lack of alcohol use registration in their medical files. CONCLUSIONS: A considerable proportion of medical patients admitted in European hospitals fulfill criteria for alcohol use disorders. These patients are frequently overlooked during hospitalization and not appropriately registered in medical records. Women, older patients, and inpatients from European areas with high local alcohol use prevalence are at higher risk associated with a non-recording of alcohol use.


Subject(s)
Alcohol Drinking/epidemiology , Hospitals/statistics & numerical data , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Cross-Sectional Studies , Europe/epidemiology , Female , Humans , Male , Medical Records/statistics & numerical data , Middle Aged , Prevalence , Risk Factors , Sex Factors , Young Adult
19.
PLoS One ; 10(11): e0142335, 2015.
Article in English | MEDLINE | ID: mdl-26555788

ABSTRACT

BACKGROUND: Vascular calcification is associated with poor cardiovascular outcome. Histochemical analysis of calcification and the expression of proteins involved in mineralization are usually based on whole section analysis, thereby often ignoring regional differences in atherosclerotic lesions. At present, limited information is available about factors involved in the initiation and progression of atherosclerosis. AIM OF THIS STUDY: This study investigates the intra-section association of micro-calcifications with markers for atherosclerosis in randomly chosen section areas of human coronary arteries. Moreover, the possible causal relationship between calcifying vascular smooth muscle cells and inflammation was explored in vitro. TECHNICAL APPROACH: To gain insights into the pathogenesis of atherosclerosis, we performed analysis of the distribution of micro-calcifications using a 3-MeV proton microbeam. Additionally, we performed systematic analyses of 30 to 40 regions of 12 coronary sections obtained from 6 patients including histology and immuno-histochemistry. Section areas were classified according to CD68 positivity. In vitro experiments using human vascular smooth muscle cells (hVSMCs) were performed to evaluate causal relationships between calcification and inflammation. RESULTS: From each section multiple areas were randomly chosen and subsequently analyzed. Depositions of calcium crystals at the micrometer scale were already observed in areas with early pre-atheroma type I lesions. Micro-calcifications were initiated at the elastica interna concomitantly with upregulation of the uncarboxylated form of matrix Gla-protein (ucMGP). Both the amount of calcium crystals and ucMGP staining increased from type I to IV atherosclerotic lesions. Osteochondrogenic markers BMP-2 and osteocalcin were only significantly increased in type IV atheroma lesions, and at this stage correlated with the degree of calcification. From atheroma area type III onwards a considerable number of CD68 positive cells were observed in combination with calcification, suggesting a pro-inflammatory effect of micro-calcifications. In vitro, invasion assays revealed chemoattractant properties of cell-culture medium of calcifying vascular smooth muscle cells towards THP-1 cells, which implies pro-inflammatory effect of calcium deposits. Additionally, calcifying hVSMCs revealed a pro-inflammatory profile as compared to non-calcifying hVSMCs. CONCLUSION: Our data indicate that calcification of VSMCs is one of the earliest events in the genesis of atherosclerosis, which strongly correlates with ucMGP staining. Our findings suggest that loss of calcification inhibitors and/or failure of inhibitory capacity is causative for the early precipitation of calcium, with concomitant increased inflammation followed by osteochondrogenic transdifferentiation of VSMCs.


Subject(s)
Atherosclerosis/pathology , Calcinosis , Coronary Vessels/pathology , Macrophages/pathology , Aged , Aged, 80 and over , Humans , Middle Aged
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