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1.
BMJ Open Respir Res ; 11(1)2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38580440

ABSTRACT

PURPOSE: This study examines the financial impact of the COVID-19 pandemic on the Colombian Health System, focusing on the adequacy of reimbursement rates for inpatient stays. The study, based on a cost of illness analysis, aims to evaluate the effectiveness of the reimbursement scheme and identify potential economic losses within the health system. PATIENTS AND METHODS: The study protocol outlines the inclusion criteria for patients >18 years with confirmed COVID-19 infection and moderate to critical disease. Patients hospitalised between June 2020 and June 2021 for at least 24 hours were included. Exclusion criteria involved pregnant patients and those initially hospitalised for non-COVID-19. RESULTS: The study included 781 patients contributing to 790 hospitalisations. Demographic and clinical characteristics were analysed, with critical illness being the most prevalent category (61%). The overall mortality rate was 20.3%, primarily observed in critically ill patients. In the general ward for moderate cases, the reimbursement rate saw a substantial increase from US$3237 in 2020 to US$6760 in 2021, surpassing median resource utilisation. However, for severe cases in the intermediate care unit, reimbursement rates decreased, indicating potential insufficiency in covering costs. In the intensive care unit for critical cases, despite improved reimbursement rates, median resource utilisation still exceeds the 2021 rate, suggesting financial insufficiency in reimbursement rates. CONCLUSION: Our study underscores the inadequacies of the previous reimbursement system in addressing the varying resource utilisation and costs associated with COVID-19 inpatient care. Our analysis reveals substantial discrepancies between estimated costs and actual resource utilisation, particularly for severe and critical cases. We advocate for government flexibility in revising reimbursement baskets, supported by pilot studies to assess effectiveness. The use of real-world evidence forms a crucial basis for informed adjustments to reimbursement levels in preparation for future pandemics. This proactive approach ensures alignment between reimbursement policies and the actual costs associated.


Subject(s)
COVID-19 , Humans , Colombia/epidemiology , Pandemics , Hospitalization , Intensive Care Units
2.
Health Syst Reform ; 9(3): 2343174, 2023 12 31.
Article in English | MEDLINE | ID: mdl-38715196

ABSTRACT

Health benefits packages in Colombia-what is covered, by whom, and at what cost-have evolved over the past thirty years. Coverage changed from two explicit health benefits packages (with benefits linked to ability to contribute) to an implicit approach that covers, in theory, everything for everyone, excluding a narrow negative list of services and health technologies. This article explores the evolution of priority setting in Colombia during two periods of major reform. Each period had its own advantages and disadvantages associated with different institutional arrangements, processes, and methodologies. Colombia's evolution provides several lessons for other low- and middle-income countries interested in institutionalizing evidence-based priority-setting.


Subject(s)
Health Care Reform , Colombia , Humans , Health Care Reform/trends , Health Priorities/trends , Insurance Benefits/trends , Insurance, Health/trends
3.
Nutrients ; 13(12)2021 Dec 08.
Article in English | MEDLINE | ID: mdl-34959949

ABSTRACT

Acute respiratory infections are an important health concern. Traditionally, polysaccharide-enriched extracts from plants, containing immunomodulatory rhamnogalacturonan-I (RG-1), were used prophylactically. We established the effects of dietary supplementation with carrot-derived RG-I (cRG-I, 0-0.3-1.5 g/day) in 177 healthy individuals (18-65 years) on symptoms following infection with rhinovirus strain 16 (RV16). Primary outcomes were changes in severity and duration of symptoms, and viral load in nasal lavage. Secondary outcomes were changes in innate immune and anti-viral responses, reflected by CXCL10 and CXCL8 levels and cell differentials in nasal lavage. In a nested cohort, exploratory transcriptome analysis was conducted on nasal epithelium. Intake of cRG-I was safe, well-tolerated and accelerated local cellular and humoral innate immune responses induced by RV16 infection, with the strongest effects at 1.5 g/d. At 0.3 g/d, a faster interferon-induced response, induction of the key anti-viral gene EIF2AK2, faster viral clearance, and reduced symptom severity (-20%) and duration (-25%) were observed. Anti-viral responses, viral clearance and symptom scores at 1.5 g/d were in between those of 0 and 0.3 g/d, suggesting a negative feedback loop preventing excessive interferon responses. Dietary intake of cRG-I accelerated innate immune and antiviral responses, and reduced symptoms of an acute respiratory viral infection.


Subject(s)
Antiviral Agents , Chemokine CXCL10/metabolism , Daucus carota/chemistry , Dietary Supplements , Immunity, Innate/drug effects , Interleukin-8/metabolism , Pectins/pharmacology , Pectins/therapeutic use , Phytotherapy , Picornaviridae Infections/drug therapy , Picornaviridae Infections/immunology , Picornaviridae Infections/virology , Rhinovirus , Adolescent , Adult , Aged , Dose-Response Relationship, Drug , Double-Blind Method , Female , Humans , Male , Middle Aged , Nasal Lavage , Patient Acuity , Pectins/isolation & purification , Picornaviridae Infections/prevention & control , Treatment Outcome , Young Adult
4.
Nutrients ; 13(3)2021 Mar 16.
Article in English | MEDLINE | ID: mdl-33809720

ABSTRACT

The prevalence of acute respiratory infections and their impact on quality of life underlies the need for efficacious solutions that are safe, sustainable and economically viable. Polysaccharides in several (traditional) plant extracts have been shown to be immunostimulatory, and some studies suggest beneficial effects against respiratory infections. The aim of this study was to (i) identify the active polysaccharide constituents from affordable and renewable crops (bell pepper and carrot) using activity-guided fractionation, (ii) evaluate in vitro effects on innate immune responses (phagocytosis and cytokine secretion), microbiota modulation and production of short chain fatty acids, followed by (iii) the evaluation of effects of a bell pepper extract enriched for the active component in a human proof of concept study. We identified rhamnogalacturonan-I (RG-I) as the nutricophore responsible for the immunostimulatory activity with substantial structural and functional equivalence between bell pepper (bp) and carrot (c). The in vitro studies showed that bpRG-I and cRG-I comprise similar immune- and microbiota modulatory potential and the human study demonstrated that bpRG-I was well tolerated and enhanced innate immune responsiveness in vivo. This is an important step towards testing the efficacy of RG-I from bpRG-I or cRG-I in an infection trial in humans.


Subject(s)
Capsicum/chemistry , Daucus carota/chemistry , Immunologic Factors/pharmacology , Pectins/pharmacology , Phytotherapy/methods , Plant Extracts/pharmacology , Adult , Aged , Cytokines/metabolism , Double-Blind Method , Female , Gastrointestinal Microbiome/drug effects , Humans , Immunologic Factors/isolation & purification , Killer Cells, Natural/drug effects , Killer Cells, Natural/physiology , Male , Middle Aged , Pectins/isolation & purification , Phagocytosis/drug effects , Plant Extracts/isolation & purification , Proof of Concept Study , Young Adult
5.
Food Chem Toxicol ; 139: 111243, 2020 May.
Article in English | MEDLINE | ID: mdl-32151604

ABSTRACT

The dietary fibre product examined is a pectic polysaccharide extract from carrot (Daucus carota), enriched for pectin fragments comprising mainly rhamnogalacturonan-I (RG-I) (abbreviated product name cRG-I). To assess the safety of cRG-I for use as food ingredient, repeated-dose oral toxicity and in vitro genotoxicity studies were conducted. In the subchronic toxicity study (OECD test guideline 408), Wistar Hannover rats received cRG-I at dietary levels (w/w) of 0%, 2.5%, 5% and 10% for 13 weeks. cRG-I induced no adverse effects in this study. The NOAEL was 10% in the diet (equivalent to 6.9 and 7.8 g cRG-I/kg body weight/day in male and female rats, respectively). A package of three in vitro genotoxicity tests (Ames, mouse lymphoma and micronucleus assay in human peripheral blood lymphocytes) was negative for induction of point mutation and chromosome damage. An initial Ames test showed a weak positive response in Salmonella typhimurium strain (TA1537). This response was non-reproducible and attributed to microbial contamination as subsequent tests with an irradiated batch of cRG-I including a repeat Ames test were negative. cRG-I was therefore considered to be non-mutagenic.


Subject(s)
DNA Damage/drug effects , Daucus carota/chemistry , Dietary Exposure/adverse effects , Pectins/toxicity , Rhamnogalacturonans/toxicity , Animals , Body Weight/drug effects , Diet , Female , Male , Micronucleus Tests , No-Observed-Adverse-Effect Level , Organ Size/drug effects , Pectins/analysis , Rats , Rats, Wistar , Rhamnogalacturonans/analysis , Risk Assessment , Toxicity Tests, Subchronic
6.
J Neurooncol ; 145(2): 233-239, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31624989

ABSTRACT

INTRODUCTION: Gliomas are tumors of the central nervous system. Despite new classifications, they are still divided in low and high-grade gliomas, being the latter of greater malignancy. The degree of malignancy is directly related with the angiogenic activity in tumoral tissues. We measured VEGF concentrations and angiogenic capacity in cerebrospinal fluid (CSF) from patients with high and low-grade gliomas. The purpose of this study was to find a biomarker that contributes in the differential diagnosis and prognosis of gliomas. METHODS: CSF was obtained from 19 individuals: 8 with low-grade gliomas, 6 with high-grade gliomas and 5 controls. VEGF concentration in CSF was measured by ELISA and the angiogenic capacity was measured by chick chorioallantoic membrane (CAM) test. RESULTS: The VEGF concentration was higher in patients with high-grade gliomas, compared to patients with low-grade gliomas and controls (2860 pg/mL ± 975 vs. 182.6 ± 37.1 and 47.4 ± 0.4, respectively). On the other hand, CSF from patients with high-grade gliomas generated a higher microvascular density (MVD) than patients with low-grade gliomas and controls (13.23 ± 0.6 vessels/9000µm2 vs. 9.3 ± 0.3 and 7.92 ± 0.2, respectively). Interestingly, there was not statistical differences in both VEGF levels and angiogenic capacity in patients with low-grade gliomas and controls. CONCLUSION: Together VEGF levels and angiogenic capacity in CSF can be used as a biological marker of gliomas malignancy.


Subject(s)
Brain Neoplasms/diagnosis , Glioma/diagnosis , Neovascularization, Pathologic , Vascular Endothelial Growth Factor A/cerebrospinal fluid , Brain Neoplasms/cerebrospinal fluid , Brain Neoplasms/physiopathology , Glioma/cerebrospinal fluid , Glioma/physiopathology , Humans , Pilot Projects , Prognosis
7.
Int. j. morphol ; 37(1): 48-53, 2019. graf
Article in Spanish | LILACS | ID: biblio-990003

ABSTRACT

RESUMEN: Los niveles de VEGF y su unión a sus receptores son etapas claves en la regulación de la angiogénesis. El ácido acetilsalicílico (AAS), ampliamente utilizado en tratamiento post infarto al miocardio ha mostrado poseer un efecto antiangiogénico en modelos tumorales. Este efecto potencialmente contraproducente requiere ser estudiado en miocardio. El objetivo del presente trabajo es cuantificar el efecto de AAS y de ácido salicílico (AS) sobre la vascularización en membrana alantocoriónica (MAC) y sobre los niveles de VEGF-A y VEGFR2 en miocardio de embriones de pollo. Para ello, treinta fetos de pollo White Leghorn fueron instilados a los 10 días de gestación con 60 µL de DMSO 0,1 % (control) o conteniendo además 0,3 µmol de AAS o AS. A las 48 horas se realizó procesamiento histológico de MAC para recuento de vasos sanguíneos y de tejido cardíaco para cuantificar VEGF-A y VEGFR2 por inmunohistoquímica. La inmunorreactividad fue cuantificada mediante Image J. Tanto AAS como AS disminuyeron la densidad microvascular de MAC. En miocardio, AAS aunque no AS, disminuyó la concentración de VEGFR2. No hubo efecto sobre VEGF-A. En nuestro modelo experimental, fetos de pollo a los 10 días de gestación también se observó el efecto inhibidor de AAS sobre la angiogénesis en MAC. La disminución de VEGFR2 en cardiomiocitos sugiere que AAS también afecta la angiogénesis en miocardio sano, modificando la disponibilidad del receptor a VEGF. Estos hallazgos nos permiten postular que AAS podría interferir con la regeneración de tejido, en situaciones como post infarto al miocardio.


SUMMARY: The VEGF levels and its binding to its receptors are key stages in the regulation of angiogenesis. Acetylsalicylic acid (ASA), widely used in post-myocardial infarction treatment, has been shown to have an anti-angiogenic effect in tumor models. This potentially counterproductive effect requires to be studied in myocardium. The aim of this study is to quantify the effect of ASA and salicylic acid (SA) on the vascularization in chick allantochorionic membrane (CAM) and on the levels of VEGF-A and VEGFR2 in myocardium of chicken embryos. Thirty White Leghorn chicken fetuses were instilled at 10 days of gestation with 60 mL of 0.1 % DMSO (control) or also containing 0.3 mmol of ASA or SA. After 48 hours, CAM histological processing was performed to count blood vessels and heart tissue to quantify VEGFA and VEGFR2 by immunohistochemistry. Immunoreactivity was quantified by Image J. Both ASA and SA decreased CAM microvascular density. In myocardium, AAS, although not SA, decreased the concentration of VEGFR2. There was no effect on VEGF-A. In our experimental model, chicken fetuses at 10 days of gestation, the inhibitory effect of ASA on angiogenesis in CAM were also observed. The decrease in VEGFR2 in cardiomyocytes suggests that ASA also affects angiogenesis in healthy myocardium, modifying the availability of the receptor to VEGF. These findings allow us to postulate that ASA could interfere with tissue regeneration, when it is required, as post myocardial infarction.


Subject(s)
Animals , Chick Embryo , Aspirin/pharmacology , Salicylic Acid/pharmacology , Vascular Endothelial Growth Factor Receptor-2/drug effects , Vascular Endothelial Growth Factor A/drug effects , Heart/drug effects , Immunohistochemistry , Neovascularization, Physiologic/drug effects , Vascular Endothelial Growth Factor Receptor-2/analysis , Vascular Endothelial Growth Factor Receptor-2/metabolism , Vascular Endothelial Growth Factor A/analysis , Vascular Endothelial Growth Factor A/metabolism
8.
Methods Mol Biol ; 1639: 161-171, 2017.
Article in English | MEDLINE | ID: mdl-28752456

ABSTRACT

Liver perfusion is a common technique used to isolate parenchymal and non-parenchymal liver cells for in vitro experiments. This method allows hepatic cells to be separated based on their size and weight, by centrifugation using a density gradient. To date, other methods allow the isolation of only one viable hepatic cellular fraction from a single mouse; either parenchymal (hepatocytes) or non-parenchymal cells (i.e., Kupffer cells or hepatic stellate cells). Here, we describe a method to isolate both hepatocytes and Kupffer cells from a single mouse liver, thereby providing the unique advantage of studying different liver cell types that have been isolated from the same organism.


Subject(s)
Cell Separation/methods , Hepatocytes/cytology , Kupffer Cells/cytology , Liver/cytology , Animals , Fluorescent Antibody Technique , Indicators and Reagents , Mice , Mice, Inbred C57BL , Perfusion , Solutions
9.
Acta Odontol Latinoam ; 28(2): 103-7, 2015.
Article in English | MEDLINE | ID: mdl-26355878

ABSTRACT

UNLABELLED: The aim of this study was to determine the relative frequency and distribution of reactive hyperplastic lesions (RHL) of the oral mucosa at the Oral Pathology Institute of the School of Dentistry at the University of Chile. This was a retrospective study of 1149 biopsies with histopathological diagnosis of RHL, performed between 2000 and 2011. The RHL were classified in 4 groups: fibrous hyperplasia (FH), pyogenic granuloma (PG), peripheral giant-cell granuloma (PGCG) and peripheral ossifying fibroma (POF). RESULTS: the most frequent RHL was FH (71. 1%), followed by PG (21.1%), PGCG (5 %) and POF (2.9%). RHLs were more frequent in women (70.7%). The most highly affected age group was the 50- to 59-year-olds (22%). The most frequent location for RHL was maxilla (24.7%), followed by cheek (20.6%), tongue (19.4%) and jaw (18.5%). The most prevalent RHL diagnosis was FH. The most frequently affected sex was female, the most frequent age range was 50-59 years, and the most frequent location, maxilla.


Subject(s)
Mouth , Chile , Female , Gingival Diseases , Gingival Neoplasms , Granuloma, Giant Cell , Humans , Middle Aged , Retrospective Studies
10.
Clin Nephrol ; 83(6): 338-44, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25816807

ABSTRACT

A multivariate analysis of risk factors for a composite endpoint of treated biopsy proven acute rejection (BPAR), graft loss, death, or loss to follow-up was undertaken in a cohort of 833 de novo kidney transplants from an international trial (A2309). Patients were randomized to everolimus (trough concentration 3-8 ng/mL or 6-12 ng/mL) with reduced cyclosporine or to mycophenolic acid (MPA) with standard cyclosporine. Cox proportional hazard modeling, incorporating a range of recipient, donor, and transplant variables, showed that treatment group (i.e., randomization to either everolimus 3-8 ng/mL or 6-12 ng/mL vs. MPA) showed no significant association with risk of the composite efficacy endpoint at either month 12 or month 24 (significance level 0.05). At month 12, Cox proportional hazard modeling showed that black race (hazard ratio (HR) 1.68; 95% confidence interval (CI) 1.08, 2.60; p=0.021), increasing donor age in years (HR 1.01; 95% CI 1.00, 1.03; p=0.022), and delayed graft function (DGF; yes vs. no, HR 2.75; 95% CI 1.82, 4.16; p< 0.001) predicted higher risk of the composite endpoint; female gender (female vs. male HR 0.67; 95% CI 0.48, 0.93; p=0.017), and < 3 HLA mismatches (HR 0.70; 95% CI 0.50, 0.99; p=0.049) were associated with reduced risk. At month 24, increasing recipient age in years (HR 0.99; 95% CI 0.98, 0.99; p=0.028), black recipient race (HR 1.62; 95% CI 1.09, 2.42; p=0.018), increasing donor age in years (HR 1.01; 95% CI 1.00, 1.02; p=0.008) and delayed graft function (DGF) (HR 2.60; 95% CI 1.78, 3.82; p<0.001) were predictive of risk. These findings show that, independently from type of immunosuppression, organ quality (expressed by DGF), donor age and recipient age, race and gender appear to be the main determinants of efficacy within 2 years after kidney transplantation.


Subject(s)
Kidney Transplantation/adverse effects , Adult , Age Factors , Cohort Studies , Delayed Graft Function/etiology , Female , Humans , Male , Middle Aged , Multivariate Analysis , Proportional Hazards Models , Risk Factors
11.
J Nephrol ; 28(5): 633-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25708913

ABSTRACT

The efficacy of de novo everolimus with reduced-exposure calcineurin inhibitor (CNI) was examined in kidney transplant subpopulations from the A2309 study that were identified to be at increased risk for efficacy events. A2309 was a 24-month, multicenter, open-label trial in which 833 de novo kidney transplant recipients were randomized to everolimus targeting 3-8 or 6-12 ng/ml with reduced-exposure cyclosporine (CsA), or mycophenolic acid (MPA) with standard-exposure CsA, all with basiliximab induction. The composite efficacy endpoint was treated biopsy-proven acute rejection (BPAR), graft loss, death, or loss to follow-up. Cox proportional hazard modeling showed male gender, younger recipient age, black race, delayed graft function, human leukocyte antigen (HLA) mismatch ≥3 and increasing donor age to be significantly predictive for the composite efficacy endpoint at months 12 or 24 post-transplant. CsA exposure was 53-75 % lower, and 46-75 % lower, in patients receiving everolimus 3-8 ng/ml or receiving everolimus 6-12 ng/ml, respectively, versus MPA-treated patients. The incidence of the composite endpoint was similar in all three treatment groups within each subpopulation analyzed. The incidence of treated BPAR was similar with everolimus 3-8 ng/ml or MPA in all subpopulations, but less frequent with everolimus 6-12 ng/ml versus MPA in patients with HLA mismatch ≥3 (p = 0.049). This post hoc analysis of a large, randomized trial suggests that a de novo regimen of everolimus with reduced-exposure CsA maintains immunosuppressive efficacy even in kidney transplant patients at increased risk for efficacy events despite substantial reductions in CsA exposure.


Subject(s)
Cyclosporine/administration & dosage , Everolimus/administration & dosage , Graft Rejection/drug therapy , Immunosuppression Therapy/methods , Kidney Transplantation/adverse effects , Adolescent , Adult , Aged , Biopsy , Dose-Response Relationship, Drug , Drug Therapy, Combination , Female , Follow-Up Studies , Graft Rejection/pathology , Humans , Immunosuppressive Agents/administration & dosage , Kidney/pathology , Kidney Failure, Chronic/surgery , Male , Middle Aged , Risk Factors , Time Factors , Treatment Outcome , Young Adult
12.
Acta odontol. latinoam ; Acta odontol. latinoam;28(2): 103-107, 2015. graf
Article in English | LILACS | ID: lil-768612

ABSTRACT

El objetivo de este estudio fue determinar la frecuencia relativa y distribución de lesiones reaccionales hiperplásicas (LRH) de la mucosa oral, presentes en el registro de biopsias del Servicio de Anatomía Patológica de la Facultad de Odontología, Universidad de Chile. Este estudio de tipo retrospectivo consistió en 1149 biopsias con diagnóstico histopatológico de LRH, entre los años 2000-2011. Las LRH se clasificaron en 5 grupos: Hiperplasia fibrosa (HF), granuloma piogénico (GP), granuloma periférico de células gigantes (GPCG) y fibroma osificante periférico(FOP). Los datos de edad y sexo de los sujetos, y de localización y tipo de lesión, fueron obtenidos del registro de biopsias de cada caso. De las LRH, la lesión más frecuente fue HF (71,1 por ciento), seguido de GP (21,1 por ciento), GPCG (5 por ciento) y FOP (2,9 por ciento) respectivamente. Las biopsias de LRH fueron mas frecuentes en mujeres (70,7 por ciento). El rango etario más afectado fue el de 50 a 59 años (22 por ciento). La localización de mayor frecuencia de LRH fue el maxilar superior (24,7 por ciento), seguida de mejilla (20,6 por ciento), lengua (19,4 por ciento), mandíbula (18,5 por ciento), labio inferior (9,9 por ciento) y labio superior (6,7 por ciento). En este estudio, de las LRH el diagnóstico más prevalente fue FH. El sexo más afectado fue el femenino, el rango etario el de 50 a 59 años y la ubicación más frecuente, maxilar superior. Estos resultados en general son concordantes con lo descrito en otros países.


The aim of this study was to determine the relative frequency and distribution of reactive hyperplastic lesions (RHL) of the oral mucosa at the Oral Pathology Institute of the School of Dentistry at the University of Chile. This was a retrospective study of 1149 biopsies with histopathological diagnosis of RHL, performed between 2000 and 2011. The RHL were classified in 4 groups: fibrous hyperplasia (FH), pyogenic granuloma (PG), peripheral giant-cell granuloma (PGCG) and peripheral ossifying fibroma (POF). Results: the most frequent RHL was FH (71. 1%), followed by PG (21.1%), PGCG (5 %) and POF (2.9%). RHLs were more frequent in women (70.7%). The most highly affected age group was the 50- to 59-year-olds (22%). The most frequent location for RHL was maxilla (24.7%), followed by cheek (20.6%), tongue (19.4%) and jaw (18.5%). The most prevalent RHL diagnosis was FH. Themost frequently affected sex was female, the most frequent agerange was 50-59 years, and the most frequent location, maxilla.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Young Adult , Middle Aged , Aged, 80 and over , Mouth Diseases/classification , Mouth Diseases/epidemiology , Gingival Hyperplasia/epidemiology , Age and Sex Distribution , Chile , Fibroma, Ossifying/epidemiology , Fibroma/epidemiology , Granuloma, Giant Cell/epidemiology , Granuloma, Pyogenic/epidemiology , Retrospective Studies , Data Interpretation, Statistical
13.
PLoS One ; 9(4): e96345, 2014.
Article in English | MEDLINE | ID: mdl-24781986

ABSTRACT

The adipokine chemerin and its receptor, chemokine-like receptor 1 (Cmklr1), are associated with insulin resistance and nonalcoholic fatty liver disease (NAFLD), which covers a broad spectrum of liver diseases, ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). It is possible that chemerin and/or Cmklr1 exert their effects on these disorders through inflammation, but so far the data have been controversial. To gain further insight into this matter, we studied the effect of whole-body Cmklr1 deficiency on insulin resistance and NAFLD. In view of the primary role of macrophages in hepatic inflammation, we also transplanted bone marrow from Cmklr1 knock-out (Cmklr1-/-) mice and wild type (WT) mice into low-density lipoprotein receptor knock-out (Ldlr-/-) mice, a mouse model for NASH. All mice were fed a high fat, high cholesterol diet containing 21% fat from milk butter and 0.2% cholesterol for 12 weeks. Insulin resistance was assessed by an oral glucose tolerance test, an insulin tolerance test, and by measurement of plasma glucose and insulin levels. Liver pathology was determined by measuring hepatic inflammation, fibrosis, lipid accumulation and the NAFLD activity score (NAS). Whole-body Cmklr1 deficiency did not affect body weight gain or food intake. In addition, we observed no differences between WT and Cmklr1-/- mice for hepatic inflammatory and fibrotic gene expression, immune cell infiltration, lipid accumulation or NAS. In line with this, we detected no differences in insulin resistance. In concordance with whole-body Cmklr1 deficiency, the absence of Cmklr1 in bone marrow-derived cells in Ldlr-/- mice did not affect their insulin resistance or liver pathology. Our results indicate that Cmklr1 is not involved in the pathogenesis of insulin resistance or NAFLD. Thus, we recommend that the associations reported between Cmklr1 and insulin resistance or NAFLD should be interpreted with caution.


Subject(s)
Fatty Liver/genetics , Insulin Resistance/genetics , Liver/pathology , Receptors, G-Protein-Coupled/genetics , Animals , Body Weight , Fatty Liver/pathology , Gene Deletion , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Non-alcoholic Fatty Liver Disease , Receptors, Chemokine
14.
Aging (Albany NY) ; 6(4): 281-95, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24751397

ABSTRACT

CD36 has been associated with obesity and diabetes in human liver diseases, however, its role in age-associated nonalcoholic fatty liver disease (NAFLD) is unknown. Therefore, liver biopsies were collected from individuals with histologically normal livers (n=30), and from patients diagnosed with simple steatosis (NAS; n=26). Patients were divided into two groups according to age and liver biopsy samples were immunostained for CD36. NAFLD parameters were examined in young (12-week) and middle-aged (52-week) C57BL/6J mice, some fed with chow-diet and some fed with low-fat (LFD; 10% kcal fat) or high-fat diet (HFD; 60% kcal fat) for 12-weeks. CD36 expression was positively associated with age in individuals with normal livers but not in NAS patients. However, CD36 was predominantly located at the plasma membrane of hepatocytes in aged NAS patients as compared to young. In chow-fed mice, aging, despite an increase in hepatic CD36 expression, was not associated with the development of NAFLD. However, middle-aged mice did exhibit the development of HFD-induced NAFLD, mediated by an increase of CD36 on the membrane. Enhanced CD36-mediated hepatic fat uptake may contribute to an accelerated progression of NAFLD in mice and humans. Therapies to prevent the increase in CD36 expression and/or CD36 from anchoring at the membrane may prevent the development of NAFLD.


Subject(s)
CD36 Antigens/biosynthesis , Hepatocytes/metabolism , Liver/metabolism , Non-alcoholic Fatty Liver Disease/metabolism , Adult , Aged , Aging , Animals , Cell Membrane/metabolism , Female , Humans , Immunoblotting , Immunohistochemistry , Male , Mice , Mice, Inbred C57BL , Middle Aged , Real-Time Polymerase Chain Reaction , Young Adult
15.
Atherosclerosis ; 232(2): 390-6, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24468153

ABSTRACT

OBJECTIVE: It is generally assumed that hepatic inflammation in obesity is linked to the pathogenesis of insulin resistance. Several recent studies have shed doubt on this view, which questions the causality of this association. This study focuses on Kupffer cell-mediated hepatic inflammation as a possible driver of insulin resistance in the absence and presence of obesity. METHODS: We used male mice deficient for the low-density lipoprotein receptor (Ldlr(-/-)) and susceptible to cholesterol-induced hepatic inflammation. Whole body and hepatic insulin resistance was measured in mice fed 4 diets for 2 and 15 weeks, i.e., chow, high-fat (HF), HF-cholesterol (HFC; 0.2% cholesterol) and HF without cholesterol (HFnC). Biochemical parameters in plasma and liver were measured and inflammation was determined using immunohistochemistry and RT-PCR. RESULTS: At 2 weeks, we did not find significant metabolic effects in either diet group, except for the mice fed a HFC diet which showed pronounced hepatic inflammation (p < 0.05) but normal insulin sensitivity. At 15 weeks, a significant increase in insulin levels, HOMA-IR, and hepatic insulin resistance was observed in mice fed a HFC, HFnC, and HF diet compared to chow-fed mice (p < 0.05). Regardless of the level of hepatic inflammation (HFC > HF, HFnC; p < 0.05) insulin resistance in mice fed HFC was no worse compared to mice on a HFnC and HF diet. CONCLUSION: These data show that cholesterol-induced hepatic inflammation does not contribute to the development of insulin resistance in male Ldlr(-/-) mice. This study suggests that Kupffer cell-driven hepatic inflammation is a consequence, not a cause, of metabolic dysfunction in obesity.


Subject(s)
Cholesterol/blood , Insulin Resistance , Liver/pathology , Receptors, LDL/genetics , Animal Feed , Animals , Diet , Dietary Fats , Glucose Tolerance Test , Hepatocytes/cytology , Inflammation , Insulin/metabolism , Kupffer Cells/cytology , Male , Mice , Mice, Knockout
16.
PLoS One ; 8(2): e57710, 2013.
Article in English | MEDLINE | ID: mdl-23469055

ABSTRACT

Disruption of the maternal environment during pregnancy is a key contributor to offspring diseases that develop in adult life. To explore the impact of chronodisruption during pregnancy in primates, we exposed pregnant capuchin monkeys to constant light (eliminating the maternal melatonin rhythm) from the last third of gestation to term. Maternal temperature and activity circadian rhythms were assessed as well as the newborn temperature rhythm. Additionally we studied the effect of daily maternal melatonin replacement during pregnancy on these rhythms. Ten pregnant capuchin monkeys were exposed to constant light from 60% of gestation to term. Five received a daily oral dose of melatonin (250 µg kg/body weight) at 1800 h (LL+Mel) and the other five a placebo (LL). Six additional pregnant females were maintained in a 14∶10 light:dark cycles and their newborns were used as controls (LD). Rhythms were recorded 96 h before delivery in the mother and at 4-6 days of age in the newborn. Exposure to constant light had no effect on the maternal body temperature rhythm however it delayed the acrophase of the activity rhythm. Neither rhythm was affected by melatonin replacement. In contrast, maternal exposure to constant light affected the newborn body temperature rhythm. This rhythm was entrained in control newborns whereas LL newborns showed a random distribution of the acrophases over 24-h. In addition, mean temperature was decreased (34.0±0.6 vs 36.1±0.2°C, in LL and control, respectively P<0.05). Maternal melatonin replacement during pregnancy re-synchronized the acrophases and restored mean temperature to the values in control newborns. Our findings demonstrate that prenatal melatonin is a Zeitgeber for the newborn temperature rhythm and supports normal body temperature maintenance. Altogether these prenatal melatonin effects highlight the physiological importance of the maternal melatonin rhythm during pregnancy for the newborn primate.


Subject(s)
Circadian Rhythm/radiation effects , Light , Mothers , Temperature , Animals , Animals, Newborn , Behavior, Animal/drug effects , Behavior, Animal/physiology , Behavior, Animal/radiation effects , Cebus , Circadian Rhythm/drug effects , Female , Male , Maternal Exposure/adverse effects , Melatonin/pharmacology , Pregnancy , Pregnancy Trimester, Third/drug effects , Pregnancy Trimester, Third/physiology , Pregnancy Trimester, Third/radiation effects , Time Factors
17.
Hepatology ; 57(2): 566-76, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22941955

ABSTRACT

UNLABELLED: Ectodomain shedding of tumor necrosis factor receptor 1 (TNFR1) provides negative feedback to the inflammatory loop induced by TNFα. As the significance of this mechanism in obesity-associated pathologies is unclear, we aimed to unravel how much TNFR1 ectodomain shedding controls the development of nonalcoholic fatty liver disease (NAFLD), as well as its role in the development of insulin resistance. We used knockin mice expressing a mutated TNFR1 ectodomain (p55(Δns)), incapable of shedding and dampen the inflammatory response. Our data show that persistent TNFα signaling through this inability of TNFR1 ectodomain shedding contributes to chronic low-grade inflammation, which is confined to the liver. In spite of this, hepatic lipid levels were not affected by the nonshedding mutation in mice fed a chow diet, nor were they worse off following 12 weeks of high-fat diet (HFD) than controls (p55(+/+)) fed an HFD. We detected inflammatory infiltrates, hepatocellular necrosis, and apoptosis in livers of p55(Δns/Δns) mice fed an HFD, suggesting advanced progression of NAFLD toward nonalcoholic steatohepatitis (NASH). Indeed, fibrosis was present in p55(Δns/Δns) mice, but absent in wildtype mice, confirming that the p55(Δns/Δns) mice had a more severe NASH phenotype. Despite low-grade hepatic inflammation, insulin resistance was not observed in p55(Δns/Δns) mice fed a chow diet, and HFD-induced insulin resistance was no worse in p55(Δns/Δns) mice than p55(+/+) mice. CONCLUSION: TNFR1 ectodomain shedding is not an essential feedback mechanism in preventing the development of hepatic steatosis or insulin resistance. It is, however, pivotal in attenuating the progression from "simple steatosis" towards a more serious phenotype with many NASH features. Targeting TNFR1 could therefore be beneficial in attenuating NASH.


Subject(s)
Fatty Liver/etiology , Receptors, Tumor Necrosis Factor, Type I/genetics , Animals , Diet, High-Fat , Female , Inflammation/etiology , Insulin Resistance/genetics , Liver/pathology , Male , Mice , Mutation , Non-alcoholic Fatty Liver Disease
18.
Curr Opin Lipidol ; 23(2): 111-21, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22274753

ABSTRACT

PURPOSE OF REVIEW: Bone marrow transplantation (BMT) technology is a firmly established tool for studying atherosclerosis. Only recently it is helping us to understand the inflammatory mechanisms leading to the development of obesity, insulin resistance and type 2 diabetes. Here we review the use of BMT as a tool for studying the metabolic syndrome. RECENT FINDINGS: Bone marrow-derived cells, and particularly monocytes and macrophages, have been a major subject in the study of atherogenesis, and they are highly amenable for research purposes because of their application in bone marrow transplantations. For example, the many pathways studied using BMT have helped unmask ABC transporters as the genes controlling reverse cholesterol transport and foam cell formation, as well as other genes like CCR2 and IκBα controlling leukocyte development, migration and activation. The invasion of leukocytes, not only in the vessel wall, but also in adipose tissue and liver, shares many common mechanisms relevant to atherosclerosis and metabolic diseases. SUMMARY: BMT is an efficient and versatile tool for assessing the roles of specific genes that are restricted to hematopoietic cells, and especially the monocytes and macrophages in metabolic syndrome and its related pathologies.


Subject(s)
Atherosclerosis/metabolism , Bone Marrow Transplantation/methods , Macrophages/metabolism , Metabolic Syndrome/metabolism , Animals , Atherosclerosis/genetics , Atherosclerosis/pathology , Genetic Predisposition to Disease/genetics , Humans , Lipid Metabolism/genetics , Metabolic Syndrome/genetics , Metabolic Syndrome/pathology , Monocytes/metabolism
19.
Atherosclerosis ; 213(2): 335-44, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20576267

ABSTRACT

Hematopoietic cells have been established as major players in cardiovascular disease, with an important role in the etiology of atherosclerotic plaque. In addition, hematopoietic cells, and in particular the cells of monocyte and macrophage lineages, have recently been unmasked as one of the main causes of metabolic abnormalities leading to insulin resistance and type 2 diabetes. With the availability of transgenic mouse models that reproduce many aspects of these diseases, research in these areas has been able to make exceptional progress. Much of the work exploring the role of hematopoietic cells has been carried out on chimeric mice made by the recipient disease model mice being given donor bone marrow cells from transgenic mice harboring a genetic alteration in a relevant pathway. Here, we will describe the potential of the bone marrow transplantation approach and discuss recent developments, including the use of virally transduced cells. We will explain some of the caveats, their effect on the experimental outcomes, and some possible solutions. Taken as a whole, this technology offers great advantages in efficiency and cost-effectiveness, and it is expected to continue to be a crucial technique in cardiovascular research work.


Subject(s)
Bone Marrow Transplantation , Cardiovascular Diseases/etiology , Hematopoietic Stem Cell Transplantation , Animals , Atherosclerosis/etiology , Female , Gastrointestinal Tract/radiation effects , Insulin Resistance , Male , Mice , Mice, Transgenic , Plaque, Atherosclerotic/etiology , Transplantation Chimera , Whole-Body Irradiation
20.
Pediatr Nephrol ; 24(12): 2459-62, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19653009

ABSTRACT

A 3-year-old girl with Alport syndrome presented with decompensated heart failure from hypertension-induced cardiomyopathy 6 months following renal biopsy. Selective renal angiography revealed a large left renal arteriovenous fistula (AVF) with poor perfusion to the left renal parenchyma. The AVF was treated by transcatheter embolization using an Amplatzer vascular plug. Her blood pressure normalized after embolization, and her cardiac function normalized over the following 4 months.


Subject(s)
Arteriovenous Fistula/therapy , Arteriovenous Malformations/therapy , Embolization, Therapeutic/instrumentation , Hypertension/pathology , Arteriovenous Fistula/diagnostic imaging , Arteriovenous Fistula/pathology , Arteriovenous Malformations/diagnostic imaging , Arteriovenous Malformations/pathology , Biopsy/instrumentation , Cardiomyopathy, Dilated/diagnostic imaging , Cardiomyopathy, Dilated/pathology , Cardiomyopathy, Dilated/therapy , Cardiotonic Agents/therapeutic use , Child, Preschool , Echocardiography , Female , Humans , Kidney/diagnostic imaging , Kidney/pathology , Kidney/surgery , Kidney Diseases/diagnostic imaging , Kidney Diseases/pathology , Kidney Diseases/therapy , Milrinone/therapeutic use , Radiography , Treatment Outcome
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