ABSTRACT
In this work, we investigate the optical properties of hafnium dioxide nanocrystals, upon X-ray irradiation, looking for spectral evolution following thermal treatments in air up to 1000 °C that modify the crystal size as well as their point defect concentrations. Radio-luminescence measurements from 10 K up to room temperature reveal a rich and evolving picture of the optical features. A complete spectral analysis of the broad luminescence spectra reveals the presence of several emission components in the visible and UV regions. The lower energy components peaking at 2.1, 2.5, and 2.9 eV are characterized by a thermal quenching energy of 0.08 eV, while the corresponding value for the UV bands at 4.1 and 4.7 eV is close to 0.23 eV. We tentatively assign the components ranging from 2 to 3 eV to the presence of optically active defects of an intrinsic nature, together with the occurrence of titanium impurities; conversely, the bands at higher energies are likely to be of an excitonic nature. The comparison with previous photo-luminescence studies allows evidencing characteristic differences between the features of luminescence emissions caused by intra-centre excitation and those occurring under ionizing irradiation. Finally, scintillation measurements in the visible range reveal the existence of a fast decay in the nanosecond time scale for the smallest hafnia nanocrystals. This study offers a clear description of HfO2 luminescence characteristics upon excitation by X-rays and can lead to a better comprehension of the structure-property relationship at the nanoscale in metal oxides.
ABSTRACT
The Erice 50 Charter titled "Strategies for Diseases Prevention and Health Promotion in Urban Areas" was unanimously approved at the conclusion of the 50th Residential Course "Urban Health. Instruments for promoting health and for assessing hygienic and sanitary conditions in urban areas", held from 29th March to 2nd April 2017 in Erice, at the "Ettore Majorana" Foundation and Centre for Scientific Culture and promoted by the International School of Epidemiology and Preventive Medicine "G. D'Alessandro" and the Study Group "Building Hygiene" of the Italian Society of Hygiene, Preventive Medicine and Public Health (SItI). At the conclusion of the intense learning experience during the Course, with more than 20 lectures, workshops and long-lasting discussions between Professors and Students, the participants identified the major points connecting urban features and Public Health, claiming the pivotal role of urban planning strategies for the management of Diseases Prevention and Health Promotion activities. The Erice 50 Charter is configured as a Decalogue for Healthy Cities and as a Think Tank for designing effective strategic actions and best practices to develop urban regeneration interventions and improve the urban quality of contemporary cities. The Decalogue is structured into the following key strategic objectives: 1. Promoting urban planning interventions that address citizens towards healthy behaviours; 2. Improving living conditions in the urban context; 3. Building an accessible and inclusive city, with a special focus on the frail population; 4. Encouraging the foundation of resilient urban areas; 5. Supporting the development of new economies and employment through urban renewal interventions; 6. Tackling social inequalities; 7. Improving stakeholders' awareness of the factors affecting Public Health in the cities; 8. Ensuring a participated urban governance; 9. Introducing qualitative and quantitative performance tools, capable of measuring the city's attitude to promote healthy lifestyles and to monitor the population's health status; 10. Encouraging sharing of knowledge and accessibility to informations. Finally, all the participants underlined that a multidisciplinary team, composed of Physicians specialized in Hygiene, Preventive Medicine, Public Health and Technicians as Architects, Urban planners and Engineers, is needed to deepen the research topic of Urban Health.
Subject(s)
Health Promotion/methods , Primary Prevention/methods , Urban Health , Humans , ItalyABSTRACT
BACKGROUND: The aim of the study was to investigate the different B-cell responses after a glucagon stimulation test (GST) versus mixed meal tolerance test (MMTT). METHODS: We conducted GST and MMTT in 10 healthy people (aged 25-40 years) and measured C-peptide, gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1) at different time points after the administration of 1 mg i.v. glucagon for GST or a liquid mixed meal for MMTT. RESULTS: The GST stimulated C-peptide showed a mean increase of 147.1%, whereas the mean increase of MMTT stimulated C-peptide was 99.82% (Δincrease = 47.2%). Maximum C-peptide level reached with the MMTT was greater than that obtained with the GST (C-pept max MMTT = 2.35 nmol/L vs C-pep max GST = 1.9 nmol/L). A positive and linear correlation was found between the GST incremental area under the curve C-peptide and the MMTT incremental area under the curve C-peptide (r = 0.618, P = .05). After GST, there was no increment of GIP and glucagon like peptide-1 levels compared to baseline levels. A positive and linear correlation between GIP and C-peptide levels was observed only for the MMTT (r = 0.922, P = .008) indicating that in the GST, the C-peptide response is independent of the incretin axis response. CONCLUSIONS: Although the 2 stimulation tests may elicit a similar response in C-peptide secretion, B-cell response to MMTT depends on a functionally normal incretin axis. These results may have implications when investigating the B-cell response in people with diabetes and for studies in which stimulated C-peptide secretion is used as primary or secondary outcome for response to therapy.
Subject(s)
C-Peptide/metabolism , Diabetes Mellitus, Type 2/diagnosis , Diagnostic Techniques, Endocrine , Gastric Inhibitory Polypeptide/pharmacology , Glucagon-Like Peptide 1/pharmacology , Glucagon/administration & dosage , Insulin-Secreting Cells/drug effects , Meals , Adult , Cross-Over Studies , Diabetes Mellitus, Type 2/physiopathology , Eating/physiology , Female , Humans , Insulin-Secreting Cells/physiology , Male , Stimulation, ChemicalABSTRACT
BACKGROUND AND AIMS: Obesity is often associated with an increased cardiovascular risk. The food industry and the associated research activities focus on formulating products that are a perfect mix between an adequate fat content and health. We evaluated whether a diet enriched with Bio-Oil Spread (SD), an olive oil-based innovative food, is cardioprotective in the presence of high-fat diet (HFD)-dependent obesity. METHODS AND RESULTS: Rats were fed for 16 weeks with normolipidic diet (ND; fat: 6.2%), HFD (fat: 42%), and ND enriched with SD (6.2% of fat + 35.8% of SD). Metabolic and anthropometric parameters were measured. Heart and liver structures were analyzed by histochemical examination. Ischemic susceptibility was evaluated on isolated and Langendorff-perfused cardiac preparations. Signaling was assessed by Western blotting. Compared to ND rats, HFD rats showed increased body weight and abdominal obesity, dyslipidemia, and impaired glucose tolerance. Morphological analyses showed that HFD is associated with heart and liver modifications (hypertrophy and steatosis, respectively), lesser evident in the SD group, together with metabolic and anthropometric alterations. In particular, IGF-1R immunodetection revealed a reduction of hypertrophy in SD heart sections. Notably, SD diet significantly reduced myocardial susceptibility against ischemia/reperfusion (I/R) with respect to HFD through the activation of survival signals (Akt, ERK1/2, and Bcl2). Systolic and diastolic performance was preserved in the SD group. CONCLUSIONS: We suggest that SD may contribute to the prevention of metabolic disorders and cardiovascular alterations typical of severe obesity induced by an HFD, including the increased ischemic susceptibility of the myocardium. Our results pave the way to evaluate the introduction of SD in human alimentary guidelines as a strategy to reduce saturated fat intake.
Subject(s)
Dietary Supplements , Metabolic Syndrome/prevention & control , Myocardial Infarction/prevention & control , Myocardial Reperfusion Injury/prevention & control , Obesity, Abdominal/prevention & control , Olive Oil/administration & dosage , Abdominal Fat/metabolism , Abdominal Fat/physiopathology , Adiposity , Animal Feed , Animals , Apoptosis , Biomarkers/blood , Blood Glucose/metabolism , Diet, High-Fat , Disease Models, Animal , Dyslipidemias/blood , Dyslipidemias/etiology , Dyslipidemias/prevention & control , Extracellular Signal-Regulated MAP Kinases/metabolism , Glucose Intolerance/blood , Glucose Intolerance/etiology , Glucose Intolerance/prevention & control , Hypertrophy, Left Ventricular/etiology , Hypertrophy, Left Ventricular/pathology , Hypertrophy, Left Ventricular/physiopathology , Hypertrophy, Left Ventricular/prevention & control , Isolated Heart Preparation , Lipids/blood , Liver/metabolism , Liver/pathology , Metabolic Syndrome/blood , Metabolic Syndrome/etiology , Metabolic Syndrome/physiopathology , Myocardial Infarction/blood , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Myocardial Reperfusion Injury/blood , Myocardial Reperfusion Injury/pathology , Myocardial Reperfusion Injury/physiopathology , Myocardium/metabolism , Myocardium/pathology , Non-alcoholic Fatty Liver Disease/blood , Non-alcoholic Fatty Liver Disease/etiology , Non-alcoholic Fatty Liver Disease/pathology , Non-alcoholic Fatty Liver Disease/prevention & control , Obesity, Abdominal/blood , Obesity, Abdominal/etiology , Obesity, Abdominal/physiopathology , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Rats, Sprague-Dawley , Receptor, IGF Type 1/metabolism , Signal Transduction , Ventricular Function, Left , Ventricular RemodelingABSTRACT
The functional His452Tyr polymorphism in the 5HT2A receptor has been described to be associated with verbal memory in healthy adults, with worse episodic memory performances in Tyr452 (T) carriers. The aim of our study was to investigate a possible effect of this polymorphism on memory performances in Alzheimer disease (AD). We enrolled 169 patients affected by probable AD. 5HT2A genotype was determined as previously described. According to their genotype, patients were divided in T carriers ( n = 111) and non-carriers ( n = 69). We evaluated the possible effect of 5HT2A polymorphism on verbal memory tasks. A one-way MANOVA analysis did not show a positive interaction between the two groups ( p > 0.05) at the baseline and at the follow-up. Nevertheless, the analyses of the single-task effect showed lower performances for non-T carriers only in Rey's recognition task. Recent data reported poorer memory performances in healthy subjects carrying the T variant, in age-dependent manner (no differences between T vs. nT carriers were observed for age >50 years). In our AD sample, we did not find significant differences in verbal memory scores in T vs. nT carriers while a significant difference was found only in attentional task. At variance with that in healthy subjects, no correlation has been found between memory profiles of AD patients and His452Tyr polymorphism.
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Phase transformations at the nanoscale represent a challenging field of research, mainly in the case of nanocrystals (NCs) in a solid host, with size-effects and interactions with the matrix. Here we report the study of the structural evolution of γ-Ga2O3 NCs in alkali-germanosilicate glass - a technologically relevant system for its light emission and UV-to-visible conversion - showing an evolution drastically different from the expected transformation of γ-Ga2O3 into ß-Ga2O3. Differential scanning calorimetry registers an irreversible endothermic process at â¼1300 K, well above the exothermic peak of γ-Ga2O3 nano-crystallization (â¼960 K) and below the melting temperature (â¼1620 K). Transmission electron microscopy and X-ray diffraction data clarify that glass-embedded γ-Ga2O3 NCs transform into LiGa5O8via diffusion-driven kinetics of Li incorporation into NCs. At the endothermic peak, ß-Ga2O3 forms from LiGa5O8 dissociation, following a nucleation-limited kinetics promoted by size-dependent order-disorder change between LiGa5O8 polymorphs. As a result of the changes, modifications of UV-excited NC light emission are registered, with potential interest for applications.
ABSTRACT
OBJECTIVE: Body weight-related insulin resistance probably plays a role in progression to type 1 diabetes, but has an uncertain impact following diagnosis. In this study, we investigated whether BMI measured at diagnosis was an independent predictor of C-peptide decline 1-year post-diagnosis. DESIGN: Multicentre longitudinal study carried out at diagnosis and up to 1-year follow-up. METHODS: Data on C-peptide were collected from seven diabetes centres in Europe. Patients were grouped according to age at diagnosis (<5 years, n=126; >5 years <10 years, n=295; >10 years <18 years, n=421; >18 years, n=410). Linear regression was used to investigate whether BMI was an independent predictor of change in fasting C-peptide over 1 year. Models were additionally adjusted for baseline insulin dose and HbA1c. RESULTS: In individuals diagnosed between 0 and 5 years, 5 and 10 years and those diagnosed >18 years, we found no association between BMI and C-peptide decline. In patients aged 10-18 years, higher BMI at baseline was associated with a greater decline in fasting C-peptide over 1 year with a decrease (ß 95% CI; P value) of 0.025 (0.010, 0.041) nM/kg per m(2) higher baseline BMI (P=0.001). This association remained significant after adjusting for gender and differences in HbA1c and insulin dose (ß=0.026, 95% CI=0.0097, 0.042; P=0.002). CONCLUSIONS: These observations indicate that increased body weight and increased insulin demand are associated with more rapid disease progression after diagnosis of type 1 diabetes in an age group 10-18 years. This should be considered in studies of ß-cell function in type 1 diabetes.
Subject(s)
Body Mass Index , C-Peptide/blood , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/diagnosis , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/pathology , Adolescent , Biomarkers/blood , Cell Count/methods , Child , Cohort Studies , Female , Humans , Longitudinal Studies , MaleABSTRACT
AIMS: C-peptide secretion is currently the only available clinical biomarker to measure residual ß-cell function in type 1 diabetes. However, the natural history of C-peptide decline after diagnosis can vary considerably dependent upon several variables. We investigated the shape of C-peptide decline over time from type 1 diabetes onset in relation to age at diagnosis, haemoglobin A1c (HbA1c) levels and insulin dose. METHODS: We analysed data from 3929 type 1 diabetes patients recruited from seven European centres representing all age groups at disease onset (childhood, adolescence and adulthood). The influence of the age at onset on ß-cell function was investigated in a longitudinal analysis at diagnosis and up to 5-years follow-up. RESULTS: Fasting C-peptide (FCP) data at diagnosis were available in 3668 patients stratified according to age at diagnosis in four groups (<5 years, n = 344; >5 years < 10 years, n = 668; >10 years < 18 years, n = 991; >18 years, n = 1655). FCP levels were positively correlated with age (p < 0.001); the subsequent decline in FCP over time was log-linear with a greater decline rate in younger age groups (p < 0.0001). CONCLUSIONS: This study reveals a positive correlation between age at diagnosis of type 1 diabetes and FCP with a more rapid decline of ß-cell function in the very young patients. These data can inform the design of clinical trials using C-peptide values as an end-point for the effect of a given treatment.
Subject(s)
Aging , C-Peptide/blood , Diabetes Mellitus, Type 1/metabolism , Hypoglycemic Agents/therapeutic use , Insulin Antibodies/blood , Insulin-Secreting Cells/metabolism , Insulin/therapeutic use , Adolescent , Adult , Age Factors , Age of Onset , Aging/metabolism , Biomarkers/blood , Child , Child, Preschool , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/drug therapy , Dose-Response Relationship, Drug , Europe , Fasting , Female , Follow-Up Studies , Humans , Longitudinal Studies , MaleABSTRACT
BACKGROUND: Glucocorticoids (GCs) are considered drugs of choice for treating nasal polyps (NPs). However, a subset of patients shows a limited clinical response even to high doses of GCs. Altered expression of glucocorticoid receptors (GRs), namely GR-alpha; and GR-beta;, is a potential mechanism underlying GC insensitivity. GCs modulate the expression of several cytokines, including transforming growth factor-beta (TGF-beta), which may contribute to cellular proliferation in NPs. The study investigates some biomolecular features of GC-resistant NPs, and examines possible differences from normal mucosa (NM). METHODOLOGY: Radioligand binding assay (binding) was used to determine GR-alpha; binding capacity; Western blotting was used to evaluate GR-alpha;, GR-beta;, and TGF-beta; expression and GR-alpha; subcellular distribution. NPs were sampled in 32 patients during ethmoidectomy; NM was taken from 15 healthy patients during rhinoplasty. RESULTS: GR-alpha; was present in NPs and NM, with lower affinity for the ligand in NPs. GR-alpha; was prevalent in the cytosol of NPs that were GR-alpha-negative to the binding assay. GR-beta was expressed in NPs and absent in the majority of NM. TGF-beta1 expression was higher in NPs than in NM. CONCLUSIONS: GR-beta and TGF-beta1 might be involved in NP pathogenesis, but their role in modulating GC sensitivity is still unclear.
Subject(s)
Nasal Polyps/physiopathology , Receptors, Glucocorticoid/physiology , Transforming Growth Factor beta1/physiology , Drug Resistance , Electrophoresis, Polyacrylamide Gel , Endoscopy , Female , Glucocorticoids/therapeutic use , Humans , Male , Middle Aged , Nasal Polyps/drug therapy , Nasal Polyps/surgery , Prednisone/therapeutic useABSTRACT
The aim of this study was to develop a preliminary characterization of the biological responses of Hediste diversicolor to polycyclic aromatic hydrocarbons (PAHs) under controlled laboratory conditions. In order to test the effects of PAH exposure, a battery of biomarkers was applied to the polychaetes by exposing them to sublethal concentrations of benzo[a]pyrene (0.1 and 0.5 mg L(-1)) for 10d under laboratory conditions. The battery of biomarkers tested included oxidative stress biomarkers (glutathione content, enzymatic activities of catalase, glutathione S-transferases, glutathione reductase, glutathione peroxidases), total oxyradical scavenging capacity (TOSC) toward peroxyl and hydroxyl radicals and activity of acyl CoA oxidase (AOX) as a marker of peroxisome proliferation measured in the entire body; lipofuscin and neutral lipid accumulations and levels of Ca(2+)-ATPase activity analyzed in the intestinal epithelium; lysosomal membrane stability and genotoxic effects measured as DNA strand breaks and frequency of micronuclei in coelomocytes. Chemical analyses were also carried out to verify the polychaete's benzo[a]pyrene (B[a]P) bioaccumulation levels after the exposure period. The results obtained indicate that B[a]P caused significant changes in most of the parameters measured in H. diversicolor. Biological responses to the organic compound were particularly significant for the biomarkers measured in the intestinal epithelium and in coelomocytes, emphasizing that these tissues were more affected during our experimental conditions. Considering the key trophic role of this benthic species in estuarine and coastal ecosystems, this study confirmed that H. diversicolor is an appropriate bioindicator of organic contamination.
Subject(s)
Benzo(a)pyrene/metabolism , Environmental Monitoring/methods , Polychaeta/metabolism , Polycyclic Aromatic Hydrocarbons/metabolism , Water Pollutants, Chemical/metabolism , Animals , Benzo(a)pyrene/analysis , Benzo(a)pyrene/toxicity , Biomarkers/metabolism , Catalase/metabolism , Glutathione/metabolism , Glutathione Peroxidase/metabolism , Glutathione Reductase/metabolism , Glutathione Transferase/metabolism , Mutagenicity Tests , Oxidative Stress , Polycyclic Aromatic Hydrocarbons/analysis , Polycyclic Aromatic Hydrocarbons/toxicity , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicityABSTRACT
AIM: Postprandial hyperglycaemia is a consequence of reduced first phase insulin response and is associated with increased cardiovascular risk and mortality. The aim of this proof-of-concept study was to investigate the safety and efficacy of treatment with buccal spray insulin (Oral-lyn™, Generex Biotechnology Corporation, Toronto, Ontario, Canada) on postprandial plasma glucose and insulin levels in subjects with impaired glucose tolerance (IGT). METHODS: A total of 19 female and 12 male Caucasian subjects, 52.2 ± 13.5 (SD) years old, having a body mass index of 33.1 ± 6 (SD) kg/m² with confirmed IGT were included in the study. Subjects were randomized to take 4, 6 or 12 Oral-lyn puffs (1 puff = 1 s.c. rapid insulin UI) split into two equal doses each, one before and the second 30 min after a standard 75 g oral glucose tolerance test (OGTT). Glucose and insulin levels were measured at baseline and 30, 60, 90, 120 and 180 min afterwards. RESULTS: Glucose fluctuations during OGTT were not modified by 4 or 6 Oral-lyn puffs. Treatment with 12 puffs was followed by 29.6% decrease in plasma glucose at 2 h and 26.8% decrease at 3 h, altogether p = 0.01. Considering all time points of the OGTT, there was a mean reduction of 15.8% in glucose levels. With 6 of the total 12 puffs used in group C there was a significant increase in the insulin levels during OGTT at 30 min (p < 0.04) but not at 2 or 3 h. No hypoglycaemic episodes were observed at any time points of the OGTT. CONCLUSIONS: This proof-of-concept study demonstrates that treatment with buccal spray insulin is a simple and valuable therapy for reducing postprandial hyperglycaemia in obese subjects with IGT. Importantly, this treatment is safe and none of the study subjects experienced hypoglycaemia.
Subject(s)
Glucose Intolerance/drug therapy , Hyperglycemia/drug therapy , Hypoglycemic Agents/administration & dosage , Insulin/administration & dosage , Postprandial Period/drug effects , Administration, Buccal , Canada , Female , Humans , Hyperglycemia/prevention & control , Hypoglycemic Agents/pharmacokinetics , Insulin/pharmacokinetics , Male , Middle Aged , Treatment OutcomeABSTRACT
Clinical and biological prognostic factors in 135 patients affected by sinonasal carcinoma treated in Piedmont. Long-term survival of patients with sinonasal carcinoma remains disappointing in spite of aggressive treatment. The aim of the study is the assessment of overall survival in a group of patients treated with a fixed protocol and the positivity of proliferation and neoangiogenesis markers (Ki-67 and VEGF). From our data it comes out that staging, histological type and treatment are the most important clinical and pathological prognostic factors, moreover surgery +/- radiotherapy is the first line treatment for these tumors. Proliferation index and neoangiogenesis plays a pivotal role in the natural history of such neoplasms.
Subject(s)
Carcinoma, Squamous Cell/mortality , Head and Neck Neoplasms/mortality , Paranasal Sinus Neoplasms/mortality , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/therapy , Female , Head and Neck Neoplasms/therapy , Humans , Italy , Male , Middle Aged , Paranasal Sinus Neoplasms/therapy , Prognosis , Squamous Cell Carcinoma of Head and Neck , Survival Rate , Young AdultSubject(s)
Chemistry , Histology , Chemistry/history , Histology/history , History, 20th Century , History, 21st Century , Humans , Italy , Societies, ScientificABSTRACT
The mdm2 oncogene product, MDM2, is an ubiquitin protein ligase that inhibits the transcriptional activity of the tumor suppressor p53 and promotes its degradation. About 50% of all human cancers present mutations or deletions in the TP53 gene. In the remaining half of all human neoplasias that express the wild-type protein, aberrations of p53 regulators, such as MDM2, account for p53 inhibition. For this reason, designing small-molecule inhibitors of the p53-MDM2 protein-protein interaction is a promising strategy for the treatment of cancers retaining wild-type p53. The development of inhibitors has been challenging. Although many small-molecule MDM2 inhibitors have shown potent in vitro activity, only a limited number of compounds have demonstrated to possess acceptable pharmacokinetic properties for in vivo evaluation. To date, the most studied chemotypes have been cis-imidazolines (such as nutlins), benzodiazepines, and spiro-oxindoles. The cis-imidazolines were the first discovered potent and selective small-molecule inhibitors of the p53-MDM2 interaction and they continue to show therapeutic potential. This review will focus on recent molecular modeling approaches (molecular dynamics, pharmacophore-based, molecular docking, structure-based design) used with the aim to better understand the behavior of these proteins and to discover new small-molecule inhibitors of the p53-MDM2 protein-protein interaction for the treatment of cancer.
Subject(s)
Antineoplastic Agents/chemistry , Proto-Oncogene Proteins c-mdm2/metabolism , Tumor Suppressor Protein p53/metabolism , Antineoplastic Agents/therapeutic use , Benzodiazepinones/chemistry , Benzodiazepinones/therapeutic use , Drug Design , Humans , Imidazolines/chemistry , Imidazolines/therapeutic use , Indoles/chemistry , Indoles/therapeutic use , Molecular Dynamics Simulation , Neoplasms/drug therapy , Oxindoles , Protein Structure, Tertiary , Proto-Oncogene Proteins c-mdm2/antagonists & inhibitors , Tumor Suppressor Protein p53/antagonists & inhibitorsABSTRACT
Alzheimer's Disease (AD) is a neurodegenerative disorder with a complex aetiology displayed by multiple pathogenic factors. The APOE varepsilon4 allele represents the only established genetic risk factor for sporadic AD; in addition, previous findings on three single nucleotide polymorphisms (SNPs) located on the APOE promoter region, have led to a growing interest in their potential role in AD pathogenesis. The -491 A/T promoter polymorphism has been the one most frequently shown to be associated with AD, as it influences the APOE coding region transcription. The aim of this study was to evaluate the possible effect of the -491 A/T polymorphism on the cognitive profile of sporadic AD patients with a disease severity ranging from mild to moderate. Our results showed that patients carrying the -491 AA genotype had poorer cognitive performances than the -491 AT ones, statistically significant in demanding tests of visual attention, especially for the late-onset AD (LOAD). No further differences on cognitive profile were observed when stratifying AA and AT patients according to their APOE genotype. These results suggest a possible functional effect of the -491 A/T promoter on the neuropsychological performances of AD. This role seems to be independent of APOE genotype. In fact the effect of -491 A/T occurs predominantly on attention while the APOE varepsilon4 allele mainly affects memory performances. According to the biological effect exerted on APOE transcription, the -491 A/T polymorphism could be considered a disease modifier more than a risk factor for sporadic AD.
Subject(s)
Alzheimer Disease/psychology , Apolipoprotein E4/genetics , Cognition Disorders/psychology , Aged , Alzheimer Disease/genetics , Cognition Disorders/genetics , Genotype , Heterozygote , Humans , Memory , Polymorphism, Genetic , Promoter Regions, GeneticABSTRACT
Alzheimer's disease (AD) is characterized by a significant reduction in AcetylCholinesterase and an increase in ButyrylCholinesterase (BuChE) activity. The existence of polymorphic regions on the BuChE gene has been previously described; the most frequently found polymorphism is the so-called K variant, which leads to a 30% decreased enzymatic activity. Different studies reported a positive association between K variant and AD, strongest among late-onset AD and Apolipoprotein E (APOE) e4 carriers. We analyzed APOE and BuChE polymorphisms in 167 AD and 59 fronto-temporal dementia (FTD) patients compared with 129 healthy controls (HC). We reported a significantly lower frequency of the BuChE K variant in AD compared with HC and FTD and a significant increased frequency of the K variant in FTD. These results are in agreement with the known increase of the BuChE activity in AD and support the evidence of different molecular pathways involved in the pathogenesis of AD and FTD.
Subject(s)
Alzheimer Disease/enzymology , Butyrylcholinesterase/metabolism , Frontotemporal Dementia/enzymology , Aged , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Apolipoprotein E4/metabolism , Butyrylcholinesterase/genetics , Female , Frontotemporal Dementia/genetics , Frontotemporal Dementia/metabolism , Gene Frequency , Genotype , Humans , Isoenzymes/metabolism , Male , Polymorphism, GeneticABSTRACT
We report on tests of a room-temperature particle counting silicon pixel detector of the Medipix2 series as the detector unit of a positron autoradiography (AR) system, for samples labelled with (18)F-FDG radiopharmaceutical used in PET studies. The silicon detector (1.98 cm(2) sensitive area, 300 microm thick) has high intrinsic resolution (55 microm pitch) and works by counting all hits in a pixel above a certain energy threshold. The present work extends the detector characterization with (18)F-FDG of a previous paper. We analysed the system's linearity, dynamic range, sensitivity, background count rate, noise, and its imaging performance on biological samples. Tests have been performed in the laboratory with (18)F-FDG drops (37-37 000 Bq initial activity) and ex vivo in a rat injected with 88.8 MBq of (18)F-FDG. Particles interacting in the detector volume produced a hit in a cluster of pixels whose mean size was 4.3 pixels/event at 11 keV threshold and 2.2 pixels/event at 37 keV threshold. Results show a sensitivity for beta(+) of 0.377 cps Bq(-1), a dynamic range of at least five orders of magnitude and a lower detection limit of 0.0015 Bq mm(-2). Real-time (18)F-FDG positron AR images have been obtained in 500-1000 s exposure time of thin (10-20 microm) slices of a rat brain and compared with 20 h film autoradiography of adjacent slices. The analysis of the image contrast and signal-to-noise ratio in a rat brain slice indicated that Poisson noise-limited imaging can be approached in short (e.g. 100 s) exposures, with approximately 100 Bq slice activity, and that the silicon pixel detector produced a higher image quality than film-based AR.
Subject(s)
Autoradiography/instrumentation , Electrons , Fluorodeoxyglucose F18 , Silicon , Animals , Brain/cytology , Cluster Analysis , Linear Models , Male , Rats , Sensitivity and Specificity , SoftwareABSTRACT
We have computationally studied the intercalation of the antitumor drug daunomycin into six stacks of Watson-Crick DNA base pairs (i.e., AT-AT, AT-TA, GC-AT, CG-TA, GC-GC, GC-CG) using density functional theory (DFT). The proton affinity of the DNA intercalator daunomycin in water was computed to be 159.2 kcal/mol at BP86/TZ2P, which is in line with the experimental observation that daunomycin is protonated under physiological conditions. The intercalation interaction of protonated daunomycin with two stacked DNA base pairs was studied through a hybrid approach in which intercalation is treated at LDA/TZP while the molecular structure of daunomycin and hydrogen-bonded Watson-Crick pairs is computed at BP86/TZ2P. We find that the affinity of the drug for the six considered base pair dimers decreases in the order AT-AT > AT-TA > GC-AT > GC-TA > GC-CG > GC-GC, in excellent agreement with experimental data on the thermodynamics of the interaction between daunomycin and synthetic polynucleotides in aqueous solution. Our analyses show that the overall stability of the intercalation complexes comes mainly from pi-pi stacking but an important contribution to the computed and experimentally observed sequence specificity comes from hydrogen bonding between daunomycin and hetero atoms in the minor groove of AT base pairs.
Subject(s)
Antibiotics, Antineoplastic/metabolism , DNA/chemistry , DNA/metabolism , Daunorubicin/metabolism , Intercalating Agents/metabolism , Antibiotics, Antineoplastic/chemistry , Base Pairing , Daunorubicin/chemistry , Hydrogen Bonding , Intercalating Agents/chemistry , Models, Chemical , Models, Molecular , Nucleic Acid Conformation , Thermodynamics , Water/chemistryABSTRACT
The implementation of a database of digitised mammograms is discussed. The digitised images were collected beginning in 1999 by a community of physicists in collaboration with radiologists in several Italian hospitals as a first step in developing and implementing a computer-aided detection (CAD) system. All 3,369 mammograms were collected from 967 patients and classified according to lesion type and morphology, breast tissue and pathology type. A dedicated graphical user interface was developed to visualise and process mammograms to support the medical diagnosis directly on a high-resolution screen. The database has been the starting point for developing other medical imaging applications, such as a breast CAD, currently being upgraded and optimised for use in a distributed environment with grid services, in the framework of the Instituto Nazionale di Fisicia Nucleare (INFN)-funded Medical Applications on a Grid Infrastructure Connection (MAGIC)-5 project.
Subject(s)
Breast Neoplasms/diagnostic imaging , Databases, Factual , Mammography/methods , Radiographic Image Interpretation, Computer-Assisted , Adult , Aged , Female , Humans , Italy , Middle Aged , Radiographic Image Enhancement , Radiographic Image Interpretation, Computer-Assisted/methods , Retrospective Studies , Sensitivity and Specificity , Tomography, X-Ray ComputedABSTRACT
Codon 129 polymorphism of the prion protein gene represents a major genetic risk factor for Creutzfeldt-Jakob disease (CJD). Both CJD and Alzheimer's disease (AD) are brain amyloidoses and it would be possible that codon 129 polymorphism plays a role in the susceptibility to AD. In order to investigate this polymorphism in AD the distribution of polymorphic codon 129 of the PRNP gene in 194 probable AD and 124 controls selected in Italy and 109 neuropathologically verified AD and 58 matched controls recruited in the USA was studied. No significant association was found for the PRNP polymorphism in AD compared to controls either in Probable or in Definite AD series even after stratification for APOE polymorphism. This study does not support a role of PRNP polymorphism as a susceptibility factor for AD.