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1.
Cogn Affect Behav Neurosci ; 20(4): 842-858, 2020 08.
Article in English | MEDLINE | ID: mdl-32700292

ABSTRACT

Relationships between gross motor skills and cardiovascular fitness with visuospatial working memory (VSWM) in children are hypothesized to be mediated by underlying functional brain mechanisms. Because there is little experimental evidence to support this mechanism, the present study was designed to investigate the relationships of gross motor skills and cardiovascular fitness with VSWM-related brain activation in 8- to 10-year-old children. Functional magnetic resonance imaging data obtained during a VSWM-task were analyzed for 80 children from grades 3 (47.5%) and 4 of 21 primary schools in the Netherlands (51.3% girls). Gross motor skills (Korper Koordinationstest für Kinder and Bruininks-Oseretsky Test of Motor Proficiency - 2nd Edition) and cardiovascular fitness (20-meter Shuttle Run Test) were assessed. VSWM-related brain activation was found in a network involving the angular gyrus, the superior parietal cortex, and the thalamus; deactivation was found in the inferior and middle temporal gyri. Although behavioral results showed significant relations of gross motor skills and cardiovascular fitness with VSWM performance, gross motor skills and cardiovascular fitness were not related to VSWM-related brain activation. Therefore, we could not confirm the hypothesis that brain activation underlies the relationship of gross motor skills and cardiovascular fitness with VSWM performance. Our results suggest that either the effects of physical activity on cognition do not necessarily go via changes in gross motor skills and/or cardiovascular fitness, or that brain activation patterns as measured with the blood-oxygen-level dependent (BOLD) signal may not be the mechanism underlying the relationships of gross motor skills and cardiovascular fitness with VSWM.


Subject(s)
Cardiorespiratory Fitness/physiology , Cerebral Cortex/physiology , Child Development/physiology , Memory, Short-Term/physiology , Motor Skills/physiology , Nerve Net/physiology , Psychomotor Performance/physiology , Space Perception/physiology , Thalamus/physiology , Visual Perception/physiology , Brain Mapping , Cerebral Cortex/diagnostic imaging , Child , Female , Humans , Magnetic Resonance Imaging , Male , Nerve Net/diagnostic imaging , Thalamus/diagnostic imaging
2.
Eur J Clin Microbiol Infect Dis ; 36(2): 361-371, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27848039

ABSTRACT

There was an increase in severe and fatal influenza cases in Greece during the 2011-2015 post-pandemic period. To investigate causality, we determined neuraminidase (NA) inhibitor susceptibility and resistance-conferring NA and hemagglutinin (HA) mutations in circulating influenza type A viruses during the pandemic (2009-2010) and post-pandemic periods in Greece. One hundred thirty-four influenza A(H1N1)pdm09 and 95 influenza A(H3N2) viruses submitted to the National Influenza Reference Laboratory of Southern Greece were tested for susceptibility to oseltamivir and zanamivir. Antiviral resistance was assessed by neuraminidase sequence analysis, as well as the fluorescence-based 50 % inhibitory concentration (IC50) method. Five influenza A(H1N1)pdm09 viruses (2.2 %) showed significantly reduced inhibition by oseltamivir (average IC50 300.60nM vs. 1.19nM) by Gaussian kernel density plot analysis. These viruses were isolated from immunocompromised patients and harbored the H275Y oseltamivir resistance-conferring NA substitution. All A(H1N1)pdm09 viruses were zanamivir-susceptible, and all A(H3N2) viruses were susceptible to both drugs. Oseltamivir-resistant viruses did not form a distinct cluster by phylogenetic analysis. Permissive mutations were detected in immunogenic and non immunogenic NA regions of both oseltamivir- resistant and susceptible viruses in the post-pandemic seasons. Several amino acid substitutions in the HA1 domain of the HA gene of post-pandemic viruses were identified. This study indicated low resistance to NAIs among tested influenza viruses. Antiviral resistance emerged only in immunocompromised patients under long-term oseltamivir treatment. Sequential sample testing in this vulnerable group of patients is recommended to characterise resistance or reinfection and viral evolution.


Subject(s)
Antiviral Agents/pharmacology , Drug Resistance, Viral , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H3N2 Subtype/drug effects , Influenza, Human/virology , Aged , Female , Genotype , Greece , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Humans , Immunocompromised Host , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza A Virus, H3N2 Subtype/genetics , Influenza A Virus, H3N2 Subtype/isolation & purification , Inhibitory Concentration 50 , Male , Microbial Sensitivity Tests , Middle Aged , Mutation, Missense , Neuraminidase/genetics , Oseltamivir/pharmacology , Viral Proteins/genetics , Zanamivir/pharmacology
3.
Br J Cancer ; 104(8): 1278-87, 2011 Apr 12.
Article in English | MEDLINE | ID: mdl-21487429

ABSTRACT

BACKGROUND: Drug resistance is a major problem in ovarian cancer. Triggering apoptosis using death ligands such as tumour necrosis factor-related apoptosis inducing ligand (TRAIL) might overcome chemoresistance. METHODS: We investigated whether acquired cisplatin resistance affects sensitivity to recombinant human (rh) TRAIL alone or in combination with cisplatin in an ovarian cancer cell line model consisting of A2780 and its cisplatin-resistant subline CP70. RESULTS: Combining cisplatin and rhTRAIL strongly enhanced apoptosis in both cell lines. CP70 expressed less caspase 8 protein, whereas mRNA levels were similar compared with A2780. Pre-exposure of particularly CP70 to cisplatin resulted in strongly elevated caspase 8 protein and mRNA levels. Caspase 8 mRNA turnover and protein stability in the presence or absence of cisplatin did not differ between both cell lines. Cisplatin-induced caspase 8 protein levels were essential for the rhTRAIL-sensitising effect as demonstrated using caspase 8 small-interfering RNA (siRNA) and caspase-8 overexpressing constructs. Cellular FLICE-inhibitory protein (c-FLIP) and p53 siRNA experiments showed that neither an altered caspase 8/c-FLIP ratio nor a p53-dependent increase in DR5 membrane expression following cisplatin were involved in rhTRAIL sensitisation. CONCLUSION: Cisplatin enhances rhTRAIL-induced apoptosis in cisplatin-resistant ovarian cancer cells, and induction of caspase 8 protein expression is the key factor of rhTRAIL sensitisation.


Subject(s)
Apoptosis/drug effects , Carcinoma/drug therapy , Caspase 8/genetics , Cisplatin/therapeutic use , Drug Resistance, Neoplasm/genetics , Ovarian Neoplasms/drug therapy , TNF-Related Apoptosis-Inducing Ligand/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Apoptosis/genetics , Carcinoma/genetics , Carcinoma/pathology , Caspase 8/metabolism , Caspase 8/physiology , Cell Line, Tumor , Cisplatin/administration & dosage , Drug Evaluation, Preclinical , Drug Resistance, Neoplasm/drug effects , Female , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Enzymologic/physiology , Gene Expression Regulation, Neoplastic/drug effects , Gene Expression Regulation, Neoplastic/physiology , Humans , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Recombinant Proteins/administration & dosage , Recombinant Proteins/pharmacology , Recombinant Proteins/therapeutic use , TNF-Related Apoptosis-Inducing Ligand/pharmacology , TNF-Related Apoptosis-Inducing Ligand/therapeutic use , Up-Regulation/drug effects , Up-Regulation/genetics , Up-Regulation/physiology
4.
Biochemistry ; 40(16): 5081-6, 2001 Apr 24.
Article in English | MEDLINE | ID: mdl-11305925

ABSTRACT

The M13 major coat protein has been extensively studied in detergent-based and phospholipid model systems to elucidate its structure. This resulted in an L-shaped model structure of the protein in membranes. An amphipathic alpha-helical N-terminal arm, which is parallel to the surface of the membrane, is connected via a flexible linker to an alpha-helical transmembrane domain. In the present study, a fluorescence polarity probe or ESR spin probe is attached to the SH group of a series of N-terminal single cysteine mutants, which were reconstituted into DOPC model membranes. With ESR spectroscopy, we measured the local mobility of N-terminal positions of the protein in the membrane. This is supplemented with relative depth measurements at these positions by fluorescence spectroscopy via the wavelength of maximum emission and fluorescence quenching. Results show the existence of at least two possible configurations of the M13 amphipathic N-terminal arm on the ESR time scale. The arm is bound either to the membrane surface or in the water phase. The removal or addition of a hydrophobic membrane-anchor by site-specific mutagenesis changes the ratio between the membrane-bound and the water phase fraction.


Subject(s)
Bacteriophage M13/chemistry , Capsid Proteins , Capsid/chemistry , Membrane Proteins/chemistry , Membranes, Artificial , Peptide Fragments/chemistry , Amino Acid Sequence , Bacteriophage M13/genetics , Capsid/genetics , Cyclic N-Oxides , Cysteine/genetics , Electron Spin Resonance Spectroscopy , Fluorescent Dyes/chemistry , Membrane Proteins/genetics , Molecular Sequence Data , Mutagenesis, Site-Directed , Naphthalenesulfonates/chemistry , Peptide Fragments/genetics , Phosphatidylcholines/chemistry , Protein Binding/genetics , Protein Structure, Tertiary/genetics , Spectrometry, Fluorescence , Spin Labels
5.
J Adv Nurs ; 32(3): 554-61, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11012796

ABSTRACT

A comparative study of the financing, provision and quality of care in nursing homes. The approach of four European countries: Belgium, Denmark, Germany and the Netherlands As result of an increase in the numbers of frail elderly people, most European countries are facing problems with the financing and provision of services by nursing homes. At the same time, the expectations of quality of these services continue to rise. The main question investigated in this study was that of how countries approach the problems of financing and service provision by nursing homes and, at the same time, attempt to increase the quality levels in these institutions. The study was conducted in Belgium, Denmark, Germany and the Netherlands. A study was made of the relevant literature and questionnaires were sent to experts in each country. The four countries are addressing the problems of financing and sufficient service provision by controlling the use of nursing home services. In addition, financial problems are approached by extending co-payments, encouraging cheaper forms of care and putting pressure on nursing homes to operate at lower costs. Problems in the provision of care are addressed by applying more selective admission criteria and offering alternative forms of care outside the nursing home. As a result nursing home beds are used for those with the greatest care-dependency. Nursing home services are adjusted to rising quality expectations by offering a greater range of provision, decreasing the number of residents per room, improving comfort and improving the training of nursing staff. Another way to increase the quality of care is to separate the housing and service functions. Many nursing homes nowadays collaborate intensively with other facilities for the elderly to cope with all these problems and changes. The workload for nursing home staff has increased because of the increasing care-dependency of residents, the demand for higher quality of services and the financial problems.


Subject(s)
Financing, Organized/organization & administration , Nursing Homes/economics , Nursing Homes/standards , Quality Assurance, Health Care/organization & administration , Quality of Health Care , Activities of Daily Living , Aged , Belgium , Denmark , Female , Germany , Health Services Research , Humans , Life Expectancy , Male , National Health Programs/organization & administration , Needs Assessment , Netherlands , Nursing Staff/organization & administration , Population Growth , Surveys and Questionnaires , Workload
6.
J Biol Chem ; 275(2): 992-8, 2000 Jan 14.
Article in English | MEDLINE | ID: mdl-10625637

ABSTRACT

3-Methyladenine which stops macroautophagy at the sequestration step in mammalian cells also inhibits the phosphoinositide 3-kinase (PI3K) activity raising the possibility that PI3K signaling controls the macroautophagic pathway (Blommaart, E. F. C., Krause, U., Schellens, J. P. M., Vreeling-Sindelárová, H., and Meijer, A. J. (1997) Eur. J. Biochem. 243, 240-246). The aim of this study was to identify PI3Ks involved in the control of macroautophagic sequestration in human colon cancer HT-29 cells. An increase of class I PI3K products (phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,4,5-triphosphate) caused by either feeding cells with synthetic lipids (dipalmitoyl phosphatidylinositol 3, 4-bisphosphate and dipalmitoyl phosphatidylinositol 3,4, 5-triphosphate) or by stimulating the enzymatic activity by interleukin-13 reduced macroautophagy. In contrast, an increase in the class III PI3K product (phosphatidylinositol 3-phosphate), either by feeding cells with a synthetic lipid or by overexpressing the p150 adaptor, stimulates macroautophagy. Transfection of a specific class III PI3K antisense oligonucleotide greatly inhibited the rate of macroautophagy. In accordance with a role of class III PI3K, wortmannin (an inhibitor of PI3Ks) inhibits macroautophagic sequestration and protein degradation in the low nanomolar range (IC(50) 5-15 nM). Further in vitro enzymatic assay showed that 3-methyladenine inhibits the class III PI3K activity. Dipalmitoyl phosphatidylinositol 3-phosphate supplementation or p150 overexpression rescued the macroautophagic pathway in HT-29 cells overexpressing a GTPase-deficient mutant of the Galpha(i3) protein suggesting that both class III PI3K and trimeric G(i3) protein signaling are required in the control macroautophagy in HT-29 cells. In conclusion, our results demonstrate that distinct classes of PI3K control the macroautophagic pathway in opposite directions. The roles of PI3Ks in macroautophagy are discussed in the context of membrane recycling.


Subject(s)
Autophagy/physiology , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositol Phosphates/metabolism , Protein Serine-Threonine Kinases , Proto-Oncogene Proteins/metabolism , Signal Transduction/physiology , Adenocarcinoma , Androstadienes/pharmacology , Autophagy/drug effects , Chromones/pharmacology , Colonic Neoplasms , Enzyme Inhibitors/pharmacology , Homeostasis , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , Kinetics , L-Lactate Dehydrogenase/analysis , Morpholines/pharmacology , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol Phosphates/pharmacology , Proto-Oncogene Proteins c-akt , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Wortmannin
7.
Pediatr Res ; 38(6): 1018-25, 1995 Dec.
Article in English | MEDLINE | ID: mdl-8618777

ABSTRACT

Important regulatory factors of intrahepatic protein synthesis and proteolysis are amino acids, glucagon, insulin, and cell volume. We have investigated the changes in these factors with development and after an overnight fast and evaluated their contribution to changes in the hepatic nitrogen balance in vivo. In the fed state, glucagon levels were highest in suckling animals and gradually declined in older rats, whereas the concentration of insulin increased during development. The amino acid concentrations in liver and plasma declined during the suckling period to levels that in vitro are highly permissive for induction of autophagic proteolysis. In all age groups investigated, fasting was associated with a drop in hepatic protein content, together with a marked decrease in hepatocellular volume and insulin concentrations. On the other hand, glucagon concentrations and the concentration of many amino acids in plasma and liver responded to fasting with a pronounced decrease in perinatal and suckling animals, but this response had become blunted at weaning and had disappeared in adult animals. These findings suggest that insulin and/or hepatocellular volume are more likely candidates as short-term physiologic regulators of the hepatic nitrogen balance than are glucagon or amino acids. In glucose-supplemented fetuses, high levels of insulin could not compensate for a decreased hepatocellular volume in averting a catabolic state, suggesting that cell volume is the more important factor. Although our study cannot discriminate between the effects of fasting on protein synthesis and degradation, our findings show unequivocally that, for a rapid growth of the liver, suckling animals have to be fed around-the-clock.


Subject(s)
Amino Acids/blood , Fasting/physiology , Liver/physiology , Nitrogen/metabolism , Animals , Animals, Suckling , Cell Size , Embryonic and Fetal Development/physiology , Fasting/blood , Glucagon/metabolism , Liver/cytology , Liver/embryology , Liver Glycogen/metabolism , Nitrogen/blood , Rats , Rats, Wistar , Starvation/physiopathology , Weaning
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