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1.
Sports (Basel) ; 12(2)2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38393281

RESUMEN

Climbing, a sport with increasing popularity, poses diverse risks and injury patterns across its various disciplines. This study evaluates the incidence and nature of climbing-related injuries, focusing on how different disciplines and climbers' personal characteristics affect these injuries. Data on injury incidence, severity, and consequences, as well as climbers' personal attributes, were collected through a questionnaire and analyzed using generalized linear models and generalized linear mixed models, Cochran-Armitage tests, and multivariate analysis. Our findings indicate a direct correlation between time spent on bouldering and lead climbing and increased injury frequency, while injury incidence decreases with time in traditional climbing. Interestingly, personal characteristics showed no significant impact on injury incidence or severity. However, distinct patterns emerged in individual disciplines regarding the recent injuries in which age and weight of climbers play a role. While the phase of occurrence and duration of consequences show no significant variation across disciplines, the intensity of the required treatment and causes of injury differ. This research provides insights into climbing injuries' complex nature, highlighting the need for tailored preventive strategies across climbing disciplines. It underscores the necessity for further investigation into the factors contributing to climbing injuries, advocating for more targeted injury prevention and safety measures in this evolving sport.

2.
Eur J Neurol ; 28(5): 1557-1565, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33449400

RESUMEN

BACKGROUND: Parkinson´s disease (PD) has a large phenotypic variability, which may, at least partly, be genetically driven including alterations of gene products. Candidates might not only be proteins associated with disease risk but also pathways that play a role in aging. OBJECTIVE: To evaluate phenotype-modifying effects of genetic variants in Klotho, a longevity gene. METHODS: We analyzed two longitudinal cohorts: one local cohort comprising 459 PD patients who underwent genotyping for the KL-VS haplotype in Klotho including a subgroup of 125 PD patients and 50 healthy controls who underwent biochemical cerebrospinal fluid (CSF) analyses of Klotho and fibroblast growth factor 23 as well as vitamin D metabolites. The second cohort comprised 297 patients from the Parkinson's Progression Markers Initiative (PPMI) for validation of genetic-clinical findings. RESULTS: PD patients carrying the KL-VS haplotype demonstrated a shorter interval between PD onset and onset of cognitive impairment (both cohorts) and higher Unified Parkinson´s Disease Rating Scale part III (UPDRS III) scores (PPMI). CSF protein levels of Klotho and fibroblast growth factor 23 were lower in PD patients irrespective of gender compared to controls. Moreover, low CSF levels of Klotho were associated with higher scores in the UPDRS III and Hoehn and Yahr Scale. CONCLUSIONS: Our results indicate that genetic variants in Klotho together with its corresponding CSF protein profiles are associated with aspects of disease severity in PD. These findings suggest that pathways associated with aging might be targets for future biomarker research in PD.


Asunto(s)
Enfermedad de Parkinson , Biomarcadores , Proteínas del Líquido Cefalorraquídeo , Estudios de Cohortes , Humanos , Longevidad , Pruebas de Estado Mental y Demencia , Enfermedad de Parkinson/genética
3.
J Clin Med ; 10(3)2021 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-33499061

RESUMEN

The hepatokine fetuin A (Fet A) has been associated with diverse pathological states such as insulin resistance, type 2 diabetes, macrovascular disease, and systemic ectopic and vascular calcification. Fet A may also play a role in tumor growth and metastasis. The biological activity of Fet A may be affected by various modifications, including phosphorylation, O- and N-glycosylation and fatty acid binding. We developed an antibody-based assay for the detection of Fet A phosphorylated at serine 312. Fatty acid pattern was determined by gas chromatography. Using the antibody, we found that the phosphorylation was stable in human plasma or serum at room temperature for 8 h. We observed that Fet A is present in several glycosylation forms in human plasma, but the extent of Ser312 phosphorylation was not associated with glycosylation. The phosphorylation pattern did not change during an oral glucose tolerance test (0-120 min). We further found that human Fet A binds preferentially saturated fatty acids (>90%) at the expense of mono- and poly-unsaturated fatty acids. Our results indicate that different molecular species of Fet A are present in human plasma and that these different modifications may determine the different biological effects of Fet A.

4.
Plants (Basel) ; 11(1)2021 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-35009067

RESUMEN

The pH of tree bark is affected by many factors, amongst them epiphytic bryophytes changing in their active state environment. Thus, we hypothesized that bryophytes can change bark acidity, dependently of the inclination of the branches, as inclination affect the water regime and particle deposition. We measured the pH under bryophyte cushions and compared it to nearby naked bark. Additionally, we compared results with experimental bark covering with neutral cover. We found that the pH of naked bark declines with decreasing inclination of trunks. Although bryophyte cover did not generally change the pH of the bark, there was a significant interaction with inclination: with higher inclination, bryophytes decrease the pH reaction of bark, while with lower inclination they increase it. One possible explanation may lie in changes to alkaline particle deposition, or conversely in the acidification of the bark by leaching. In addition, an experiment with a neutral cover showed that naked bark covering would substantially increase pH. As, on average, bryophytes do not change the pH of bark, there can be mutual interference between the alkalizing effect of the bark cover itself and the acidifying biological effect of bryophytes.

5.
Exp Clin Endocrinol Diabetes ; 128(10): 644-653, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30986881

RESUMEN

Glucose-stimulated insulin secretion (GSIS) is the gold standard for ß-cell function. Both experimental and clinical diabetology, i. e., preceding transplantation of isolated human islets, depend on functional testing. However, multiple factors influence GSIS rendering the comparison of different in vitro tests of glucose responsiveness difficult. This study examined the influence of bovine serum albumin (BSA)-coupled fatty acids on GSIS. Isolated islet preparations of human donors and of 12-months old mice displayed impaired GSIS in the presence of 0.5% FFA-free BSA compared to 0.5% BSA (fraction V, not deprived from fatty acids). In aged INS-1E cells, i. e. at a high passage number, GSIS became highly sensitive to FFA-free BSA. Readdition of 30 µM palmitate or 30 µM oleate to FFA-free BSA did not rescue GSIS, while the addition of 100 µM palmitate and the raise of extracellular Ca2+from 1.3 to 2.6 mM improved glucose responsiveness. A high concentration of palmitate (600 µM), which fully activates FFA1, largely restored insulin secretion. The FFA1-agonist TUG-469 also increased insulin secretion but to a lesser extent than palmitate. Glucose- and TUG-induced Ca2+oscillations were impaired in glucose-unresponsive, i. e., aged INS-1E cells. These results suggest that fatty acid deprivation (FFA-free BSA) impairs GSIS mainly through an effect on Ca2+sensitivity.


Asunto(s)
Ácidos Grasos no Esterificados/metabolismo , Glucosa/farmacología , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Insulinoma , Compuestos de Anilina/farmacología , Animales , Calcio/metabolismo , Bovinos , Línea Celular Tumoral , Humanos , Ratones , Palmitatos/farmacología , Fenilpropionatos/farmacología
6.
J Clin Endocrinol Metab ; 104(6): 2041-2053, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-30541128

RESUMEN

CONTEXT: The effect of a lifestyle intervention to reduce liver fat content in nonalcoholic fatty liver disease in humans is influenced by genetics. We hypothesized that the amino acid exchange in human Gly388Arg (mouse homolog: Gly385Arg) in fibroblast growth factor receptor 4 (FGFR4), which regulates bile acid, lipid, and glucose metabolism, could determine hepatic lipid accumulation and insulin sensitivity. Mechanisms of this substitution were studied in mice under normal chow and high-fat diets. DESIGN: In humans, the Gly388Arg polymorphism was studied for its relationship with changes in liver fat content and insulin sensitivity during 9 months of a lifestyle intervention. We also studied a knock-in mouse strain with an Arg385 allele introduced into the murine FGFR4 gene under normal chow and high-fat diets. RESULTS: In humans, the FGFR4 Arg388 allele was not associated with liver fat content or insulin sensitivity in subjects who were overweight and obese before lifestyle intervention. However, it was associated with less decrease in liver fat content and less increase in insulin sensitivity during the intervention. In mice receiving normal chow, the FGFR4 Arg385 allele was associated with elevated hepatic triglyceride content, altered hepatic lipid composition, and increased hepatic expression of genes inducing de novo lipogenesis and glycolysis. Body fat mass and distribution, glucose tolerance, and insulin sensitivity were unaltered. The FGFR4 Arg385 allele had no effect on glucose or lipid metabolism under the high-fat diet. CONCLUSION: Our data indicate that the FGFR4 Arg388(385) allele affects hepatic lipid and glucose metabolism specifically during healthy caloric intake.


Asunto(s)
Lipogénesis/genética , Enfermedad del Hígado Graso no Alcohólico/dietoterapia , Obesidad/dietoterapia , Receptor Tipo 4 de Factor de Crecimiento de Fibroblastos/genética , Adulto , Animales , Glucemia/análisis , Glucemia/metabolismo , Dieta Saludable , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Femenino , Estudios de Seguimiento , Técnicas de Sustitución del Gen , Prueba de Tolerancia a la Glucosa , Glucólisis/genética , Humanos , Resistencia a la Insulina/genética , Hígado/química , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Transgénicos , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/patología , Obesidad/sangre , Obesidad/etiología , Obesidad/metabolismo , Polimorfismo de Nucleótido Simple , Receptor Tipo 4 de Factor de Crecimiento de Fibroblastos/metabolismo , Triglicéridos/análisis , Triglicéridos/metabolismo
7.
Nutrients ; 10(9)2018 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-30227635

RESUMEN

Fatty liver is tightly associated with insulin resistance and the development of type 2 diabetes. I148M variant in patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene is associated with high liver fat but normal insulin sensitivity. The underlying mechanism of the disassociation between high liver fat but normal insulin sensitivity remains obscure. We investigated the effect of I148M variant on hepatic lipidome of subjects with or without fatty liver, using the Lipidyzer method. Liver samples of four groups of subjects consisting of normal liver fat with wild-type PNPLA3 allele (group 1); normal liver fat with variant PNPLA3 allele (group 2); high liver fat with wild-type PNPLA3 allele (group 3); high liver fat with variant PNPLA3 allele (group 4); were analyzed. When high liver fat to normal liver fat groups were compared, wild-type carriers (group 3 vs. group 1) showed similar lipid changes compared to I148M PNPLA3 carriers (group 4 vs. group 2). On the other hand, in wild-type carriers, increased liver fat significantly elevated the proportion of specific DAGs (diacylglycerols), mostly DAG (FA18:1) which, however, remained unchanged in I148M PNPLA3 carriers. Since DAG (FA18:1) has been implicated in hepatic insulin resistance, the unaltered proportion of DAG (FA18:1) in I148M PNPLA3 carriers with fatty liver may explain the normal insulin sensitivity in these subjects.


Asunto(s)
Diglicéridos/sangre , Hígado Graso/genética , Resistencia a la Insulina/genética , Lipasa/genética , Hígado/metabolismo , Proteínas de la Membrana/genética , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Biomarcadores/sangre , Glucemia/metabolismo , Estudios de Casos y Controles , Hígado Graso/sangre , Hígado Graso/diagnóstico , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Insulina/sangre , Masculino , Persona de Mediana Edad , Fenotipo
8.
Metabolism ; 88: 22-30, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30195474

RESUMEN

BACKGROUND: The activation of hepatic stellate cells (HSCs) plays a crucial role in liver fibrosis, however the role of HSCs is less understood in hepatic insulin resistance. Since in the liver cGMP-dependent protein kinase I (cGKI) was detected in HSC but not in hepatocytes, and cGKI-deficient mice that express cGKI selectively in smooth muscle but not in other cell types (cGKI-SM mice) displayed hepatic insulin resistance, we hypothesized that cGKI modulates HSC activation and insulin sensitivity. MATERIALS AND METHODS: To study stellate cell activation in cGKI-SM mice, retinol storage and gene expression were studied. Moreover, in the human stellate cell line LX2, the consequences of cGKI-silencing on gene expression were investigated. Finally, cGKI expression was examined in human liver biopsies covering a wide range of liver fat content. RESULTS: Retinyl-ester concentrations in the liver of cGKI-SM mice were lower compared to wild-type animals, which was associated with disturbed expression of genes involved in retinol metabolism and inflammation. cGKI-silenced LX2 cells showed an mRNA expression profile of stellate cell activation, altered matrix degradation and activated chemokine expression. On the other hand, activation of LX2 cells suppressed cGKI expression. In accordance with this finding, in human liver biopsies, we observed a negative correlation between cGKI mRNA and liver fat content. CONCLUSIONS: These results suggest that the lack of cGKI possibly leads to stellate cell activation, which stimulates chemokine expression and activates inflammatory processes, which could disturb hepatic insulin sensitivity.


Asunto(s)
Proteína Quinasa Dependiente de GMP Cíclico Tipo I/metabolismo , Células Estrelladas Hepáticas/citología , Animales , Biopsia , Línea Celular Transformada , Quimiocinas/metabolismo , Proteína Quinasa Dependiente de GMP Cíclico Tipo I/genética , Hígado Graso/enzimología , Hígado Graso/metabolismo , Femenino , Células Estrelladas Hepáticas/metabolismo , Humanos , Hígado/enzimología , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Noqueados , ARN Mensajero/metabolismo , ARN Interferente Pequeño/genética
9.
J Clin Endocrinol Metab ; 103(9): 3299-3309, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-29931171

RESUMEN

Purpose: Recently, alterations in maternal lipid metabolism were associated with gestational diabetes mellitus (GDM). However, detailed plasma lipid profiles and their relevance for placental and fetal metabolism are currently not understood. Methods: Maternal and placental lipid profiles were characterized in women with GDM and women with normal glucose tolerance (NGT). Inflammatory gene expression was compared in placentas and primary term trophoblasts between the groups. In addition, trophoblasts were stimulated with nonesterified fatty acids (NEFAs), and effects on gene expression were quantified. Finally, placental macrophage content and cord blood concentrations of inflammatory parameters and NEFAs were compared between women with GDM and women with NGT with similar body mass index (BMI). Results: Palmitate and stearate levels were elevated in both maternal plasma and placental tissue of women with GDM. Placental GDM-associated elevations of IL6, IL8, and TLR2 expression were reflected in trophoblasts derived from women with GDM. Stimulation of primary trophoblasts with palmitate led to increased mRNA expression and protein release of the cytokine IL6 and the chemokine IL8. In line with this, elevated amounts of CD68-positive cells were quantified in the placental tissue of women with GDM. No GDM-associated elevations in a range of inflammatory parameters and NEFAs in cord blood of NGT vs GDM neonates was found. Conclusions: GDM, independently of BMI, altered maternal plasma NEFAs and the placental lipid profile. GDM was associated with trophoblast and whole-placenta lipoinflammation; however, this was not accompanied by elevated concentrations of inflammatory cytokines or NEFAs in neonatal cord blood.


Asunto(s)
Diabetes Gestacional/metabolismo , Placenta/metabolismo , Adulto , Antropometría/métodos , Antígenos CD/análisis , Antígenos de Diferenciación Mielomonocítica/análisis , Índice de Masa Corporal , Células Cultivadas , Citocinas/sangre , Diabetes Gestacional/sangre , Diabetes Gestacional/patología , Ácidos Grasos no Esterificados/sangre , Femenino , Sangre Fetal/metabolismo , Expresión Génica , Humanos , Mediadores de Inflamación/metabolismo , Lípidos/análisis , Placenta/patología , Embarazo , ARN Mensajero/genética , Trofoblastos/metabolismo
11.
Am J Physiol Endocrinol Metab ; 314(3): E266-E273, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29138227

RESUMEN

The liver is a central regulator of whole body glucose, and lipid homeostasis and hepatokines, like fetuin-A, have been identified as markers and mediators of fatty liver-induced cardiometabolic risk. The closely related protein fetuin-B was shown to be upregulated in the fatty liver and to impact on glucose homeostasis in mice. In the present study we aimed to test the relevance of these findings in humans. In 55 subjects, hepatic mRNA expression of both hepatokines, fetuin-A and fetuin-B, associated positively with liver triglyceride content, whereas only fetuin-A expression associated with the homeostatic model assessment of insulin resistance. In 220 subjects who underwent precise metabolic phenotyping, circulating fetuin-A, but not fetuin-B, associated positively with liver fat content, and negatively with insulin sensitivity, measured during the oral glucose tolerance test (OGTT) and during the euglycemic, hyperinsulinemic clamp. Both circulating fetuin-A and fetuin-B correlated positively with the glucose area under the curve during the OGTT, but after additional adjustment for insulin sensitivity this relationship remained significant only for fetuin-B. In conclusion, despite the fact that the two hepatokines, fetuin-A and fetuin-B, are upregulated in the state of hepatic steatosis in humans, it appears that they differently impact on glucose homeostasis. Our data are in agreement with observations that fetuin-A can alter insulin signaling and that fetuin-B may regulate glucose homeostasis via so far unknown effects, possibly on glucose effectiveness.


Asunto(s)
Hígado Graso/sangre , Hígado Graso/genética , Fetuína-B , alfa-2-Glicoproteína-HS , Anciano , Estudios de Cohortes , Hígado Graso/metabolismo , Hígado Graso/patología , Femenino , Fetuína-B/análisis , Fetuína-B/genética , Fetuína-B/metabolismo , Prueba de Tolerancia a la Glucosa , Humanos , Resistencia a la Insulina/fisiología , Hígado/metabolismo , Hígado/patología , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/patología , ARN Mensajero/análisis , ARN Mensajero/metabolismo , Regulación hacia Arriba/genética , alfa-2-Glicoproteína-HS/análisis , alfa-2-Glicoproteína-HS/genética , alfa-2-Glicoproteína-HS/metabolismo
12.
Exp Clin Endocrinol Diabetes ; 126(2): 123-129, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28750430

RESUMEN

OBJECTIVE: Diabetes mellitus affects almost one in 10 individuals in Germany. So far, little is known about the diabetes prevalence in maximum care hospitals. We assessed the diabetes prevalence, proportion of undiagnosed cases, the effectiveness of diabetes screening in a university hospital, the consequences for hospital stay and acquired complications. RESEARCH DESIGN AND METHODS: Over a 4 week period we determined HbA1c from 3 733 adult patients which were hospitalized at the university hospital of Tuebingen and had an available blood sample. Diabetes diagnosis was defined as HbA1c≥6.5% and/or previously documented diabetes diagnosis, prediabetes was defined as HbA1c≥5.7% and <6.5% without history of previous diabetes. RESULTS: 23.68% of the patients had prediabetes and 22.15% had diabetes with a high variation between the specialised departments (range 5-43%). The rate of unknown diabetes was 3.7%, the number needed to screen was 17 in patients older than 50 years. Patients with diabetes had a prolonged hospital stay compared to the mean length of stay for their diagnosis related group (diabetes: 1.47±0.24 days; no diabetes: -0.18±0.13 days, p=0.0133). The prevalence of hospital acquired complications was higher in diabetic patients (diabetes: 197 of 630; no diabetes: 447 of 2 459, p<0.0001). CONCLUSIONS: Every fourth patient in the university hospital had diabetes and every second had either prediabetes or diabetes. It is also worthwhile to screen for unknown diabetes in patients over the age of 50. The high prevalence and negative consequences of diabetes require screening and intensified specialized diabetes treatment in hospitals.


Asunto(s)
Diabetes Mellitus/sangre , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiología , Hemoglobina Glucada/análisis , Hospitalización/estadística & datos numéricos , Hospitales Universitarios/estadística & datos numéricos , Tamizaje Masivo/normas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alemania/epidemiología , Humanos , Persona de Mediana Edad , Estado Prediabético/sangre , Estado Prediabético/diagnóstico , Estado Prediabético/epidemiología , Prevalencia , Adulto Joven
13.
Mol Metab ; 6(3): 256-266, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28271032

RESUMEN

OBJECTIVE: Recently, we have shown that Bezafibrate (BEZ), the pan-PPAR (peroxisome proliferator-activated receptor) activator, ameliorated diabetes in insulin deficient streptozotocin treated diabetic mice. In order to study whether BEZ can also improve glucose metabolism in a mouse model for fatty liver and type 2 diabetes, the drug was applied to TallyHo mice. METHODS: TallyHo mice were divided into an early (ED) and late (LD) diabetes progression group and both groups were treated with 0.5% BEZ (BEZ group) or standard diet (SD group) for 8 weeks. We analyzed plasma parameters, pancreatic beta-cell morphology, and mass as well as glucose metabolism of the BEZ-treated and control mice. Furthermore, liver fat content and composition as well as hepatic gluconeogenesis and mitochondrial mass were determined. RESULTS: Plasma lipid and glucose levels were markedly reduced upon BEZ treatment, which was accompanied by elevated insulin sensitivity index as well as glucose tolerance, respectively. BEZ increased islet area in the pancreas. Furthermore, BEZ treatment improved energy expenditure and metabolic flexibility. In the liver, BEZ ameliorated steatosis, modified lipid composition and increased mitochondrial mass, which was accompanied by reduced hepatic gluconeogenesis. CONCLUSIONS: Our data showed that BEZ ameliorates diabetes probably via reduced steatosis, enhanced hepatic mitochondrial mass, improved metabolic flexibility and elevated hepatic insulin sensitivity in TallyHo mice, suggesting that BEZ treatment could be beneficial for patients with NAFLD and impaired glucose metabolism.


Asunto(s)
Bezafibrato/farmacología , Diabetes Mellitus/tratamiento farmacológico , Hígado Graso/tratamiento farmacológico , Animales , Bezafibrato/metabolismo , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Experimental/tratamiento farmacológico , Modelos Animales de Enfermedad , Glucosa/metabolismo , Hipolipemiantes/metabolismo , Insulina/metabolismo , Resistencia a la Insulina/fisiología , Metabolismo de los Lípidos , Hígado/metabolismo , Masculino , Ratones , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Obesidad/sangre , Receptores Activados del Proliferador del Peroxisoma/metabolismo
14.
Int Immunopharmacol ; 39: 295-306, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27505858

RESUMEN

The idea of using killed microorganisms or their parts for a stimulation of immunity in the cancer immunotherapy is very old, but the question of interactions and binding of these preparations to tumor cells has not been addressed so far. The attachment of Zymosan A and both Gram-positive and Gram-negative bacteria to tumor cells was tested in in vivo experiments. This binding was accomplished by charge interactions, anchoring based on hydrophobic chains and covalent bonds and proved to be crucial for a strong immunotherapeutic effect. The establishment of conditions for simultaneous stimulation of both Toll-like and phagocytic receptors led to very strong synergy. It resulted in tumor shrinkage and its temporary or permanent elimination. The role of neutrophils in cancer immunotherapy was demonstrated and the mechanism of their action (frustrated phagocytosis) was proposed. Finally, therapeutic approaches applicable for safe human cancer immunotherapy are discussed. Heat killed Mycobacterium tuberculosis covalently attached to tumor cells seems to be promising tool for this therapy.


Asunto(s)
Antineoplásicos/uso terapéutico , Inmunoterapia/métodos , Listeria monocytogenes/inmunología , Melanoma/terapia , Mycobacterium tuberculosis/inmunología , Neoplasias Cutáneas/terapia , Zimosan/uso terapéutico , Animales , Calor , Humanos , Inmunidad , Inmunomodulación , Células Asesinas Naturales/inmunología , Listeria monocytogenes/química , Melanoma/inmunología , Melanoma Experimental , Ratones , Ratones Endogámicos C57BL , Mycobacterium tuberculosis/química , Trasplante de Neoplasias , Neutrófilos/inmunología , Fagocitosis , Neoplasias Cutáneas/inmunología , Carga Tumoral , Zimosan/química
15.
J Clin Endocrinol Metab ; 100(12): E1568-74, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26439088

RESUMEN

CONTEXT: Previous studies revealed that the common sequence variant I148M in patatin-like phospholipase domain-containing protein 3 (PNPLA3) is associated with liver fat content and liver diseases, but not with insulin resistance. Recent data suggest that the PNPLA3 I148M variant has reduced retinyl-palmitate lipase activity in hepatic stellate cells. OBJECTIVE: We hypothesized that the PNPLA3 I148M variant is associated with elevated retinyl-palmitate storage in human liver as a potential link to the clinical pathology. Design/Setting and Participants: Using HPLC, we quantified the retinoid metabolites in liver tissue extracts obtained from 42 human subjects, including 13 heterozygous and six homozygous carriers of the minor PNPLA3 I148M variant. MAIN OUTCOME MEASURE: Retinyl-palmitate is elevated in human livers of homozygous PNPLA3 I148M allele carriers Results: The PNPLA3 I148M variant was associated with a significant increase (1.4-fold) in liver fat. The content of retinyl-palmitate was elevated and the ratio of retinol/retinyl-palmitate was reduced in liver extracts obtained from homozygous PNPLA3 I148M minor allele carriers. In a multivariate model including liver fat content, these differences remained significant independent of liver fat content. The content of the minor retinyl-fatty acid esters was similarly increased in homozygous PNPLA3 I148M carriers. CONCLUSIONS: The increased content of hepatic retinyl-palmitate and the reduced ratio of retinol/retinyl-palmitate in PNPLA3 I148M minor allele carriers support in vitro findings of an altered retinyl-palmitate lipase activity. Our results indicate that the PNPLA3 I148M variant is relevant for the retinyl-palmitate content in human liver, providing a possible link to chronic liver disease.


Asunto(s)
Lipasa/genética , Hígado/metabolismo , Proteínas de la Membrana/genética , Palmitatos/metabolismo , Retinoides/metabolismo , Anciano , Alelos , Ácidos Grasos/metabolismo , Hígado Graso/genética , Hígado Graso/metabolismo , Femenino , Heterocigoto , Homocigoto , Humanos , Metabolismo de los Lípidos/genética , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Triglicéridos/metabolismo , Vitamina A/metabolismo
16.
Diabetologia ; 57(10): 2103-7, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24972532

RESUMEN

AIMS/HYPOTHESIS: The common sequence variant I148M of the patatin-like phospholipase domain-containing protein 3 gene (PNPLA3) is associated with increased hepatic triacylglycerol (TAG) content, but not with insulin resistance, in humans. The PNPLA3 (I148M) variant was previously reported to alter the specificity of the encoded enzyme and subsequently affect lipid composition. METHODS: We analysed the fatty acid composition of five lipid fractions from liver tissue samples from 52 individuals, including 19 carriers of the minor PNPLA3 (I148M) variant. RESULTS: PNPLA3 (I148M) was associated with a strong increase (1.75-fold) in liver TAGs, but with no change in other lipid fractions. PNPLA3 (I148M) minor allele carriers had an increased n-3 polyunsaturated fatty acid (PUFA) α-linolenic acid content and reductions in several n-6 PUFAs in the liver TAG fraction. Furthermore, there was a strong inverse correlation between n-6 PUFA and TAG content independent of PNPLA3 genotype. In a multivariate model including liver fat content, PNPLA3 genotype and fatty acid composition, two significant differences could be exclusively attributed to the PNPLA3 (I148M) minor allele: reduced stearic acid and increased α-linolenic acid content in the hepatic TAG fraction. CONCLUSIONS: These changes therefore suggest a mechanism to explain the PNPLA3 (I148M)-dependent increase in liver fat content without causing insulin resistance. Stearic acid can induce insulin resistance, whereas α-linolenic acid may protect against it.


Asunto(s)
Lipasa/genética , Hígado/metabolismo , Proteínas de la Membrana/genética , Ácidos Grasos Insaturados/metabolismo , Genotipo , Humanos , Ácidos Linolénicos/metabolismo , Metabolismo de los Lípidos/genética , Metabolismo de los Lípidos/fisiología , Triglicéridos/metabolismo
17.
Z Naturforsch C J Biosci ; 68(3-4): 133-8, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23819309

RESUMEN

A new and simple analytical method is described for the determination of the IC50 values of the inhibitors of the hydrolysis of acetylcholine (ACh) or acetylthiocholine (ATCh) by cholinesterases. The method is based on monitoring the time course of the pH value during the uninhibited and inhibited reaction. It requires only a pH meter with a suitable pH measuring cell and a small thermostated stirred batch reactor. The method has been validated for twelve different types of cholinesterase inhibitors. The determined IC50 values are comparable to those obtained by independent, more complicated, and expensive methods (Ellman's and pH-stat).


Asunto(s)
Inhibidores de la Colinesterasa/farmacología , Concentración de Iones de Hidrógeno , Concentración 50 Inhibidora
18.
J Clin Endocrinol Metab ; 97(12): E2288-92, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23015656

RESUMEN

CONTEXT: Increased hepatic de novo lipogenesis (DNL) in response to dietary sugar is implicated in the pathophysiology of fatty liver. Saturated fatty acids are the product of DNL and exert lipotoxic effects that promote liver fat accumulation. Desaturation of fatty acids by stearoyl-CoA desaturase 1 (SCD1) can prevent these deleterious effects. Here we investigated whether DNL and SCD1 are activated in parallel by dietary sugar and influence liver fat accumulation. METHODS: In 20 healthy subjects (eight females and 12 males, aged 30.5 ± 2.0 yr, body mass index 25.9 ± 0.5 kg/m(2)) who received a 4-wk lipogenic diet supplemented with 150 g/d of monosaccharides, hepatic SCD1 activity and DNL were determined using validated fatty acid ratios (16:1n-7/16:0; 16:0/18:2n-6) in very low-density lipoprotein triglycerides. Liver fat content was measured by localized (1)H-magnetic resonance spectroscopy. RESULTS: At baseline, liver fat content was positively associated with the DNL (r = 0.54, P = 0.01) but not the SCD1 activity index (r = 0.16, P = 0.49). Dietary sugar supplementation increased liver fat content and DNL and SCD1 activity indices (+33, +19, and +8%, respectively). The increase of the DNL index was strongly related to the changes in liver fat content during the sugar supplementation (r = 0.75, P = 0.0001) but showed no association with changes in the SCD1 activity (P > 0.35). After the monosaccharide supplementation, the DNL index was still positively associated with liver fat content (r = 0.52, P = 0.02), whereas SCD1 activity showed a strong negative correlation with liver fat content (r = -0.63, P = 0.002). CONCLUSIONS: DNL is closely linked with hepatic steatosis under dietary conditions rich in monosaccharides. Our data suggest that the individual hepatic SCD1 activity is a determinant of liver fat accumulation under lipogenic dietary conditions.


Asunto(s)
Dieta Aterogénica , Grasas de la Dieta/farmacología , Metabolismo de los Lípidos , Hígado/efectos de los fármacos , Estearoil-CoA Desaturasa/metabolismo , Adulto , Carbohidratos de la Dieta/administración & dosificación , Carbohidratos de la Dieta/farmacología , Grasas de la Dieta/administración & dosificación , Activación Enzimática/efectos de los fármacos , Femenino , Salud , Humanos , Individualidad , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/fisiología , Lipogénesis/efectos de los fármacos , Lipogénesis/fisiología , Lipoproteínas VLDL/sangre , Lipoproteínas VLDL/metabolismo , Hígado/enzimología , Hígado/metabolismo , Masculino , Triglicéridos/sangre , Triglicéridos/metabolismo
19.
Bioresour Technol ; 101(15): 6281-3, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20335028

RESUMEN

Homological series of 14 achiral derivates and series of five chiral derivates of imidazole were tested in vitro as inhibitors of hydrolysis of acetylcholine using enzyme preparation of acetylcholinesterase from electric eel. The batch stirred reactor at 25 degrees C, pH 8 (phosphate buffer), ionic strength 0.11 M and catalytic activity of the enzyme preparation 0.14 U ml(-1) of the reaction mixture were used. The temporal dependences of actual concentrations of acetylcholine, choline and acetic acid were determined by an original HPLC method. For all used inhibitors, these time dependences conform with the probability of more than 90% to the model of competitive irreversible inhibition. All kinetic constants including k(3) defining the rate of inhibition (0.38-5.3M(-1)s(-1)) and qualified estimation of the absolute acetylcholinesterase concentration in the reaction mixture (40-110 nM) were determined.


Asunto(s)
Acetilcolinesterasa/química , Inhibidores de la Colinesterasa/química , Electrophorus/metabolismo , Imidazoles/química , Animales , Activación Enzimática , Estabilidad de Enzimas
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