Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 40
Filter
1.
Oper Dent ; 48(3): 237-244, 2023 May 01.
Article in English | MEDLINE | ID: mdl-36917629

ABSTRACT

This manuscript reports a three-year follow-up of a case of gingival conditioning with a provisional composite veneer prior to diastema closure and tooth recontouring with direct composites. This conservative treatment resulted in a natural and harmonious smile.


Subject(s)
Diastema , Gingival Diseases , Tooth , Humans , Composite Resins/therapeutic use , Follow-Up Studies , Esthetics, Dental , Dental Restoration, Permanent/methods , Diastema/therapy , Dental Veneers
2.
J Endocrinol Invest ; 42(1): 37-44, 2019 Jan.
Article in English | MEDLINE | ID: mdl-29603098

ABSTRACT

PURPOSE: Epigenetic traits are influenced by clinical variables; interaction between DNA methylation (DNAmeth) and bariatric surgery-induced weight loss has been scarcely explored. We investigated whether DNAmeth of genes encoding for molecules/hormones regulating appetite, food intake or obesity could predict successful weight outcome following Roux-en-Y gastric bypass (RYGB). METHODS: Forty-five obese individuals with no known comorbidities were stratified accordingly to weight decrease one-year after RYGB (excess weight loss, EWL ≥ 50%: good responders, GR; EWL < 50%: worse responders, WR). DNAmeth of leptin (LEP), ghrelin (GHRL), ghrelin receptor (GHSR) and insulin-growth factor-2 (IGF2) was assessed before intervention. Single nucleotide polymorphisms of genes affecting DNAmeth, DNMT3A and DNMT3B, were also determined. RESULTS: At baseline, type 2 diabetes was diagnosed by OGTT in 13 patients. Post-operatively, GR (n = 23) and WR (n = 22) achieved an EWL of 67.7 ± 9.6 vs 38.2 ± 9.0%, respectively. Baseline DNAmeth did not differ between GR and WR for any tested genes, even when the analysis was restricted to subjects with no diabetes. A relationship between GHRL and LEP methylation profiles emerged (r = 0.47, p = 0.001). Searching for correlation between DNAmeth of the studied genes with demographic characteristics and baseline biochemical parameters of the studied population, we observed a correlation between IGF2 methylation and folate (r = 0.44, p = 0.003). Rs11683424 for DNMT3A and rs2424913 for DNMT3B did not correlate with DNAmeth of the studied genes. CONCLUSIONS: In severely obese subjects, the degree of DNAmeth of some genes affecting obesity and related conditions does not work as predictor of successful response to RYGB.


Subject(s)
Appetite/physiology , DNA Methylation/physiology , Gastric Bypass/trends , Obesity/genetics , Obesity/surgery , Weight Loss/physiology , Adult , Bariatric Surgery/trends , Cohort Studies , Epigenesis, Genetic/physiology , Female , Humans , Male , Middle Aged , Obesity/metabolism , Obesity, Morbid/genetics , Obesity, Morbid/metabolism , Obesity, Morbid/surgery , Predictive Value of Tests , Treatment Outcome
3.
Mol Psychiatry ; 23(6): 1394-1401, 2018 06.
Article in English | MEDLINE | ID: mdl-28461701

ABSTRACT

Repeated presentations of a previously conditioned stimulus lead to a new form of learning known as extinction, which temporarily alters the response to the original stimulus. Previous studies have shown that the consolidation of extinction memory requires de novo protein synthesis. However, the role of specific nodes of translational control in extinction is unknown. Using auditory threat conditioning in mice, we investigated the role of mechanistic target of rapamycin complex 1 (mTORC1) and its effector p70 S6 kinase 1 (S6K1) in the extinction of auditory threat conditioning. We found that rapamycin attenuated the consolidation of extinction memory. In contrast, genetic deletion and pharmacological inhibition of S6K1, a downstream effector of mTORC1, blocked within-session extinction, indicating a role for S6K1 independent of protein synthesis. Indeed, the activation of S6K1 during extinction required extracellular signal-regulated kinase (ERK) activation in the basolateral nucleus of the amygdala (BLA) and was necessary for increased phosphorylation of the GluA1 (Thr840) subunit of the AMPA receptor following extinction training. Mice exposed to brief uncontrollable stress showed impaired within-session extinction as well as a downregulation of ERK and S6K1 signaling in the amygdala. Finally, using fiber photometry we were able to record calcium signals in vivo, and we found that inhibition of S6K1 reduces extinction-induced changes in neuronal activity of the BLA. These results implicate a novel ERK-S6K1-GluA1 signaling cascade critically involved in extinction.


Subject(s)
Extinction, Psychological/physiology , Ribosomal Protein S6 Kinases, 90-kDa/metabolism , Amygdala/metabolism , Amygdala/physiology , Animals , Basolateral Nuclear Complex/metabolism , Conditioning, Classical/physiology , Conditioning, Operant , Fear/physiology , Learning , MAP Kinase Signaling System , Male , Mechanistic Target of Rapamycin Complex 1/metabolism , Memory/physiology , Mice , Mice, Inbred C57BL , Phosphorylation , Receptors, AMPA/metabolism , Ribosomal Protein S6 Kinases, 70-kDa/genetics , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Ribosomal Protein S6 Kinases, 90-kDa/genetics , Sirolimus/pharmacology
4.
J Radiol Prot ; 38(1): 394-406, 2018 03.
Article in English | MEDLINE | ID: mdl-29214980

ABSTRACT

The Brazilian Nuclear Energy Commission (cnen) has been making a constant effort to keep up to date with international standards and national needs to strengthen the status of radiological protection of the country. The guidelines related to radiation therapy facilities have been revised in the last five years in order to take into consideration the most relevant aspects of the growing technology as well as to mitigate the accidents or incidents observed in practice. Hence, clinical dosimeters have gained special importance in this matter. In the present work, we discuss the effectiveness of regulation and inspections to the enforcement of instrument calibration accuracy for the improvement of patient dosimetry and quality control. As a result, we observed that the number of calibrated instruments, mainly well chambers, is increasing each year. The same behavior is observed for instruments employed in technologically advanced radiation treatments such as intensity modulated radiotherapy, volumetric therapy and stereotatic radiosurgery. We ascribe this behavior to the new regulation.


Subject(s)
Radiation Protection , Radiotherapy/methods , Brazil , Calibration , Guideline Adherence , Humans , Radiometry , Radiotherapy/economics , Radiotherapy/instrumentation
5.
J Biol Regul Homeost Agents ; 31(2): 503-508, 2017.
Article in English | MEDLINE | ID: mdl-28685559

ABSTRACT

3,5-diiodo-L-thyronine (T2), a naturally existing iodothyronine, has biological effects on humans, but no information is available on its action on pancreatic b-cells. We evaluated its effect vs triiodothyronine (T3), on glucose-induced insulin secretion in INS-1e cells, a rat insulinoma line, and on human islets. INS-1e were incubated in the presence/absence of T2 or T3 (0.1 nmol/L-10 µmol/L), and glucose (3.3, 7.5, 11.0, and 20 mmol/L). Insulin release and content (at 11.0 and 20 mmol/L glucose) were significantly (p less than 0.01) stimulated by 1-100 nmol/L T2 and 0.1 nmol/L-1.0 µmol/L T3, and inhibited with higher concentrations of both (1–10 µmol/L T2 and 10 µmol/L T3). Human islets were incubated with 3.3 mmol/L glucose in presence/absence of T3 or T2 (0.1 nmol/L, 0.1 µmol/L, and 1 µmol/L). T2 (0.1 nmol/L-0.1 µmol/L) significantly (p less than0.01) stimulated insulin secretion, while higher concentrations (1 µmol/L) inhibited it. A modest increase in insulin secretion was evidenced with 1 µmol/L T3. In conclusion, T2 and T3 have a direct regulatory role in insulin secretion, depending on their concentrations and the glucose level itself. At concentrations near the physiological range, T2 enhances glucose-induced insulin secretion in both rat b-cells and human islets.


Subject(s)
Diiodothyronines/pharmacology , Glucose/pharmacology , Insulin-Secreting Cells/metabolism , Insulin/metabolism , Triiodothyronine/pharmacology , Animals , Cell Line, Tumor , Dose-Response Relationship, Drug , Humans , Insulin Secretion , Rats
6.
J Intern Med ; 282(2): 175-186, 2017 08.
Article in English | MEDLINE | ID: mdl-28503820

ABSTRACT

BACKGROUND: P2X7 receptor (P2X7R), trigger of acute inflammatory responses via the NLRP3 inflammasome, is hyperfunctioning in patients with Sjögren's syndrome (SS), where it stimulates IL-18 production. Some patients with SS develop a mucosa-associated lymphoid tissue non-Hodgkin's lymphoma (MALT-NHL). OBJECTIVES: To prospectively evaluate the involvement and the putative prognostic role of this inflammatory pathway in the development of MALT-NHL. METHODS: A total of 147 women with SS have been prospectively followed for a mean of 52 months, relating the expression and function of the P2X7R-inflammasome axis in salivary glands and circulating lymphomonocytes to the prognosis and the degree of the disease. RESULTS: At baseline, gene expression of P2X7R and of the inflammasome components NLRP3, caspase-1 and IL-18 increased according to the presence of germinative centres and was higher in autoantibody-positive individuals and strongly higher in those developing a MALT-NHL over the follow-up. Glandular expression of IL-18 was threefold higher in MALT-NHL than in controls or in the other patients with SS. P2X7R did not colocalize with generic markers of inflammatory infiltrate, like CD20, being selectively expressed by epithelial cells. P2X4R, sharing functional characteristics with P2X7R, did not differ in SS and controls. The increased P2X7R gene and protein expression was tissue specific, no difference being observed in peripheral lymphomonocytes between SS with MALT-NHL and SS not developing MALT-NHL. CONCLUSION: We propose the P2X7R-inflammasome axis as a novel potential pathway involved in both SS exocrinopathy and lymphomagenesis, reinforcing the hypothesis of a key role of IL-18, via its increased P2X7R-mediated production, in the pathogenesis of lymphoproliferative malignancies, and opening novel opportunities for the early diagnosis of lymphoproliferative complications and the development of potential targeted therapies.


Subject(s)
Inflammasomes/metabolism , Lymphoma, B-Cell, Marginal Zone/etiology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Receptors, Purinergic P2X7/metabolism , Sjogren's Syndrome/complications , Sjogren's Syndrome/physiopathology , Female , Gene Expression , Humans , Inflammasomes/genetics , Interleukin-18/genetics , Interleukin-18/physiology , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Lymphocytes/metabolism , Male , Middle Aged , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Prognosis , Prospective Studies , Receptors, Purinergic P2X7/genetics , Risk Factors , Salivary Glands/metabolism , Sjogren's Syndrome/metabolism
7.
Diabetes Metab ; 43(6): 512-520, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28499695

ABSTRACT

AIM: SGLT2 inhibitors reduce renal glucose uptake through an insulin-independent mechanism. They also increase glucagon concentration, although the extent to which this is due to a direct effect on pancreatic alpha cells remains unclear. METHODS: In the present work, αTC1 cells treated with the SGLT2 inhibitor dapagliflozin (Dapa) were analyzed for glucose transporters, molecular mediators of hormone secretion, glucagon and GLP-1 release, and the effects of somatostatin. Data were validated in murine and human pancreatic islets. RESULTS: SLC5A2 (the SGLT2-encoding gene) was nearly undetectable in αTC1 cells, not even by a digital PCR technique using different probes. In contrast, SLC5A1 (the SGLT1-encoding gene) was constitutively abundant in αTC1 cells and in islets, and increased with Dapa. This was associated with greater glucagon release, preceded by increased expression of preproglucagon and HNF4α. Looking at the candidate intracellular signalling pathway, reduced PASK and increased AMPK-α2 expression were also detected. GLUT1 and GLUT2, as well as regulators of glucagon release and alpha-cell phenotype (chromogranin A, paired box 6, proprotein convertase 1/2, synaptophysin), were unaffected by Dapa, as were GLP-1 receptor expression and GLP-1 release. Low glucose did not influence the stimulatory effect of Dapa on glucagon release, but was instead almost fully reverted by SLC5A1 silencing. When the effect of Dapa on AMPK and PASK, emerging regulators of lipid and glucose metabolism, was tested, upregulated AMPK-α2 appeared to be involved in molecular signalling. CONCLUSION: Our study has shown that, in αTC1 cells, Dapa acutely upregulates SGLT1 expression and increases glucagon release through an SGLT1-dependent mechanism, with SGLT2 expression virtually undetectable. These results suggest the involvement of SGLT1 in modulating glucagon increases following SGLT2 inhibition.


Subject(s)
Benzhydryl Compounds/pharmacology , Glucagon-Secreting Cells/drug effects , Glucagon/metabolism , Glucosides/pharmacology , Sodium-Glucose Transporter 1/metabolism , Sodium-Glucose Transporter 2 Inhibitors , Sodium-Glucose Transporter 2/metabolism , Animals , Cell Line , Cells, Cultured , Gene Silencing , Glucagon-Like Peptide 1/metabolism , Glucagon-Secreting Cells/metabolism , Glucose/metabolism , Humans , Mice , Signal Processing, Computer-Assisted , Sodium-Glucose Transporter 1/genetics , Somatostatin
8.
Int J Obes (Lond) ; 40(1): 102-11, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26122028

ABSTRACT

BACKGROUND/OBJECTIVES: Soluble factors and cell-derived extracellular vesicles (EVs) are crucial tissue repair mediators in cell-based therapy. In the present study, we investigate the therapeutic impact of EVs released by adipose tissue-derived stem cells (ASCs) recovered from obese subjects' visceral and subcutaneous tissues. METHODS: ASCs were recovered from 10 obese (oASCs) and 6 non-obese (nASCs) participants and characterized. In selected experiments, nASCs and oASCs were cultured with palmitic acid (PA) or high glucose (HG), respectively. EVs from obese (oEVs) and non-obese (nEVs) subjects' visceral and subcutaneous ASCs were collected after ultracentrifugation and analyzed for their cargo: microRNA-126 (miR-126), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 2 (MMP-2), and for their biological effects on endothelial cells (ECs). Western blotting analysis and loss- and gain-of function experiments were performed. RESULTS: oEVs show impaired angiogenic potential compared with nEVs. This effect depends on EV cargo: reduced content of VEGF, MMP-2 and, more importantly, miR-126. We demonstrate, using gain- and loss-of-function experiments, that this reduced miR-126 content leads to Spred1 upregulation and the inhibition of the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway in ECs. We also show that PA treatment of nASCs translates into the release of EVs that recapitulate oEV cargo. Moreover, HG treatment of oASCs further reduces miR-126 EV content and EV-mediated in vitro angiogenesis. Finally, impaired pro-angiogenic potential is also detected in EVs released from obese subcutaneous adipose tissue-derived ASCs. CONCLUSIONS: These results indicate that obesity impacts on EV pro-angiogenic potential and may raise concerns about the use of adipose tissue-derived EVs in cell-based therapy in the obese setting.


Subject(s)
Adult Stem Cells/metabolism , Adult Stem Cells/pathology , Extracellular Vesicles/metabolism , MicroRNAs/metabolism , Microvessels/metabolism , Obesity/metabolism , Obesity/pathology , Subcutaneous Fat/cytology , Adipogenesis/drug effects , Adult Stem Cells/drug effects , Cell Differentiation/drug effects , Cells, Cultured , Endothelial Cells/metabolism , Endothelial Cells/pathology , Humans , Intra-Abdominal Fat/metabolism , Intra-Abdominal Fat/pathology , Obesity/physiopathology , Subcutaneous Fat/metabolism , Subcutaneous Fat/pathology , Vascular Endothelial Growth Factor A/metabolism
9.
Intern Med J ; 45(1): 74-9, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25371101

ABSTRACT

BACKGROUND: Intense physical stress might promote inflammatory responses, whereas a regular physical exercise has positive influence. Little is known on the acute metabolic and inflammatory responses to different levels of strenuous exercise in trained athletes. AIM: To compare the short-term effect of two different ultra-endurance competitions on the inflammatory profile in male triathletes. METHODS: We studied 14 Ironman (IR) and 13 Half Ironman (HIR) before and after their own specific race. We assessed body composition and measured blood cells, lipids, iron metabolism and plasma levels of some acute-phase cytokines and inflammatory markers. RESULTS: After the race, IR showed reduced total body water and fat-free mass, not related with the duration of exercise, and increased white cells and platelets; high-density lipoprotein levels also increased. IR, but not HIR, showed reduced iron levels, increased ferritin and transferrin, reduced % saturated transferrin. HIR showed higher basal interleukin (IL)-6, tumour necrosis factor (TNF)-α, IL-10, IL-1ß than IR; however, the post-performance rise was greater in IR. Irisin increased only in HIR and osteocalcin decreased in IR. In the whole study group, delta of white blood cells was directly related with delta of monocyte chemoattractant protein 1, and Δ ferritin was inversely related with Δosteocalcin. CONCLUSIONS: A single ultra-endurance competition induces an inflammatory response depending on the duration of physical effort, with increased acute-phase cytokines, and an altered iron metabolism. Irisin, whose biological meaning is still uncertain, seems to be associated with acute variations of some metabolic parameters.


Subject(s)
Biomarkers/blood , Cytokines/blood , Inflammation/blood , Physical Exertion/physiology , Athletes , Body Composition , Healthy Volunteers , Humans , Inflammation/physiopathology , Male
10.
Minerva Chir ; 69(6): 321-329, 2014 Dec.
Article in Italian | MEDLINE | ID: mdl-25017957

ABSTRACT

AIM: The aim of this retrospective study was to compare the results of two different mesh fixation methods in laparoscopic transabdominal preperitoneal hernioplasty (TAPP): tacker vs. synthetic cyanoacrylate glue. METHODS: The study group includes 70 patients with bilateral and monolateral recurrent inguinal hernia undergoing transabdominal preperitoneal repair (TAPP) in the period 2011-2013. A polypropylene mesh was fixed in group A (N.=35) with titanium tacks (EndoUniversal stapler, Covidien) or in group B (N.=35) with synthetic cyanoacrylate glue (Glubran-2, GEM). Patient outcome was assessed by the following variables: sex, mean age, ASA score, intra- and postoperative morbidity, hospitalization, postoperative acute and chronic pain, recurrence rate. The observation period was 24 months, with a mean follow-up of 10.5 months (range, 1-23) for Group A and 11 months (range, 2-24) for Group B. RESULTS: No difference between the two groups was observed with respect to mean operative time and hospitalization. In all cases, surgery was successfully concluded laparoscopically. Intraoperative complications occurred in 1 patient of the group A and consisted of a urinary bladder injury, which was immediately sutured. Postoperative complication rate was 5.7% (4 patients, of whom 3 in group A and 1 in group B). In each group we detected one recurrence within 6 (group A) and 18 months (group B) postsurgery; both patients were treated with a re-TAPP. Postoperative pain at 6 months from surgery, measured by visual analogue score (VAS), was reported by 4 patients in the group A and in no case of the group B (P=0.04). CONCLUSION: Data from this study demonstrate the advantages of synthetic cyanoacrylate glue for mesh fixation in laparoscopic transabdominal preperitoneal inguinal hernia repair, compared to titanium tacks. The use of this surgical glue was associated with a significantly reduced risk for developing chronic groin pain and a shortened hospital stay. Nevertheless, further studies with longer follow-up periods are needed to confirm our encouraging results.

11.
Curr Med Chem ; 21(20): 2219-36, 2014.
Article in English | MEDLINE | ID: mdl-24606498

ABSTRACT

Bladder carcinoma (BC) is the most common urinary malignant tumor. In the light of the unsuccessful current therapies and their side effects, new pharmacological strategies are needed. In addition to the well known therapeutic possibilities described in the first section, we focused our attention on very recent and innovative tools to approach this target (new drug candidates from epigenetic modulators to endothelin receptor inhibitors, improved technological formulations, active principles from plants, and dietary components). Then, in the last paragraph, we analyzed the etiology of recurrent BC, with particular attention to cellular microenvironment. In fact, the incidence of recurrence is up to 90%, and 25% of tumours show progression towards invasiveness.


Subject(s)
Antineoplastic Agents/therapeutic use , Urinary Bladder Neoplasms/therapy , Animals , Antineoplastic Agents/chemistry , Humans , Molecular Targeted Therapy , Neoplasm Invasiveness , Neoplasm Metastasis , Recurrence , Urinary Bladder Neoplasms/diagnosis , Urinary Bladder Neoplasms/genetics
12.
J Intern Med ; 274(5): 480-9, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23906036

ABSTRACT

OBJECTIVE: Innate and adaptive immunity may contribute to gland dysfunction in patients with primary Sjögren's syndrome (pSS). The P2X7 receptor (P2X7 R)-NLRP3 inflammasome complex modulates the release of the inflammatory cytokines IL-1ß and IL-18. The presence of P2X7 R in salivary glands suggests an interesting scenario for the initiation and amplification of the innate immune response in pSS. Therefore, the aim of this study was to assess the role of the P2X7 R-NLRP3 inflammasome in pSS. SUBJECTS AND METHODS: Twenty-one consecutive patients with pSS according to the American-European Consensus Group criteria and 15 patients with sicca syndrome (i.e. without Sjögren's syndrome, non-SS) were enrolled in this study, together with six control (CTL) subjects. Expression of the P2X7R-NLRP3 platform and IL-18 was determined by real-time PCR and western blotting in gland specimens and peripheral lymphomonocytes; data were related to patients\x92 clinical, serological and histopathological characteristics. The presence of IL-18 was determined in gland and saliva samples. RESULTS: P2X7 R expression was significantly higher in salivary glands from individuals with pSS than in those from non-SS and CTL subjects. Accordingly, the gene expression levels of the inflammasome components NLRP3, ASC and caspase-1 were significantly higher in pSS gland specimens, and this was paralleled by an increased expression of mature IL-18 in pSS saliva samples. The expression of both the P2X7 R and the inflammasome components was a marker of disease-related glandular involvement, being increased in patients with anti-Ro/SSA positivity and correlated with focus score. CONCLUSION: The results of this study suggest an involvement of the P2X7 R-inflammasome-caspase-1-IL-18 axis in the development of pSS exocrinopathy. This finding provides the basis for studying the complex mechanisms underlying pSS, as well as for developing novel potential therapeutic strategies.


Subject(s)
Inflammasomes/physiology , Inflammation/physiopathology , Receptors, Purinergic P2X7/physiology , Sjogren's Syndrome/physiopathology , Blotting, Western , Carrier Proteins/analysis , Carrier Proteins/physiology , Case-Control Studies , Female , Humans , Interleukin-18/analysis , Interleukin-18/physiology , Interleukin-1beta/analysis , Interleukin-1beta/physiology , Middle Aged , Monocytes/chemistry , Monocytes/physiology , NLR Family, Pyrin Domain-Containing 3 Protein , Real-Time Polymerase Chain Reaction , Receptors, Purinergic P2X7/analysis , Salivary Glands/chemistry , Salvia/chemistry , Sjogren's Syndrome/immunology
13.
Exp Clin Endocrinol Diabetes ; 120(4): 210-6, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22328114

ABSTRACT

OBJECTIVE: We aimed at evaluating the impact of short and prolonged mild manipulations of intracellular nitric oxide (NO) bioavailability on the main features of insulin secretion and whether NO promotes mitochondrial biogenesis in isolated ß-cells. MATERIALS/METHODS: INS-1E ß-cells were exposed to either the intracellular NO donor, hydroxylamine (HA), or the NO synthase inhibitor, L-nitro-arginine-methyl-ester (L-NAME), at concentrations lower than 2.0 mM. Glucose and arginine-induced insulin secretion (GIIS and AIIS) were measured after short (1 h) or prolonged (48 h) exposure to L-NAME 1.0 and 2.0 mM or HA 0.4 and 0.8 mM, lower concentrations were also evaluated for the 1 h effects. Basal insulin secretion (BIS), with either HA or L-NAME added to culture media, and peroxisome proliferators-activated receptor γ coactivator 1α (PGC-1α), nuclear respiratory factor-1 (NRF-1), and mitochondrial DNA transcription factor-A (Tfam) gene expression during chronic HA supplementation were also measured. RESULTS: Neither L-NAME nor HA affected insulin release at glucose 3.3 mM or in cell culture (BIS). Both short and prolonged cell exposure to L-NAME potentiated GIIS though with a flat dose-response curve while HA inhibited GIIS only at the highest concentration. AIIS was prevented by short exposure to L-NAME and potentiated by HA, while it did not respond to prolonged incubations. Prolonged cell exposure to HA had no effect on PGC-1α, NRF-1 or Tfam gene expression. CONCLUSION: In INS1E cells an intact NO synthesis is necessary to limit insulin release in response to acute glucose gradients and to fully respond to arginine while intracellular NO enrichment above the physiologic levels further inhibits GIIS and potentiate AIIS only when excessive. Prolonged NO manipulations do not affect AIIS, BIS or mitochondrial biogenesis.


Subject(s)
Hydroxylamine/pharmacology , Insulin-Secreting Cells/drug effects , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Donors/pharmacology , Nitric Oxide/metabolism , Animals , Arginine/pharmacology , Cells, Cultured , Dose-Response Relationship, Drug , Glucose/pharmacology , Insulin/metabolism , Insulin/pharmacology , Insulin Secretion , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/physiology , Intracellular Fluid/drug effects , Intracellular Fluid/metabolism , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/physiology , Rats , Time Factors
14.
Med Phys ; 38(6): 3050-61, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21815378

ABSTRACT

PURPOSE: Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging play an important role in the segmentation of functioning parts of organs or tumours, but an accurate and reproducible delineation is still a challenging task. In this work, an innovative iterative thresholding method for tumour segmentation has been proposed and implemented for a SPECT system. This method, which is based on experimental threshold-volume calibrations, implements also the recovery coefficients (RC) of the imaging system, so it has been called recovering iterative thresholding method (RIThM). The possibility to employ Monte Carlo (MC) simulations for system calibration was also investigated. METHODS: The RIThM is an iterative algorithm coded using MATLAB: after an initial rough estimate of the volume of interest, the following calculations are repeated: (i) the corresponding source-to-background ratio (SBR) is measured and corrected by means of the RC curve; (ii) the threshold corresponding to the amended SBR value and the volume estimate is then found using threshold-volume data; (iii) new volume estimate is obtained by image thresholding. The process goes on until convergence. The RIThM was implemented for an Infinia Hawkeye 4 (GE Healthcare) SPECT/CT system, using a Jaszczak phantom and several test objects. Two MC codes were tested to simulate the calibration images: SIMIND and SimSet. For validation, test images consisting of hot spheres and some anatomical structures of the Zubal head phantom were simulated with SIMIND code. Additional test objects (flasks and vials) were also imaged experimentally. Finally, the RIThM was applied to evaluate three cases of brain metastases and two cases of high grade gliomas. RESULTS: Comparing experimental thresholds and those obtained by MC simulations, a maximum difference of about 4% was found, within the errors (+/- 2% and +/- 5%, for volumes > or = 5 ml or < 5 ml, respectively). Also for the RC data, the comparison showed differences (up to 8%) within the assigned error (+/- 6%). ANOVA test demonstrated that the calibration results (in terms of thresholds or RCs at various volumes) obtained by MC simulations were indistinguishable from those obtained experimentally. The accuracy in volume determination for the simulated hot spheres was between -9% and 15% in the range 4-270 ml, whereas for volumes less than 4 ml (in the range 1-3 ml) the difference increased abruptly reaching values greater than 100%. For the Zubal head phantom, errors ranged between 9% and 18%. For the experimental test images, the accuracy level was within +/- 10%, for volumes in the range 20-110 ml. The preliminary test of application on patients evidenced the suitability of the method in a clinical setting. CONCLUSIONS: The MC-guided delineation of tumor volume may reduce the acquisition time required for the experimental calibration. Analysis of images of several simulated and experimental test objects, Zubal head phantom and clinical cases demonstrated the robustness, suitability, accuracy, and speed of the proposed method. Nevertheless, studies concerning tumors of irregular shape and/or nonuniform distribution of the background activity are still in progress.


Subject(s)
Algorithms , Neoplasms/diagnostic imaging , Tomography, Emission-Computed, Single-Photon/methods , Tumor Burden , Biological Transport , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/secondary , Calibration , Glioma/diagnostic imaging , Glioma/pathology , Humans , Lung Neoplasms/pathology , Monte Carlo Method , Neoplasms/pathology , Phantoms, Imaging
15.
Diabetologia ; 54(9): 2430-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21499674

ABSTRACT

AIM/HYPOTHESIS: Renal resistive index is a useful measure for quantifying alterations in renal blood flow. In the present study we evaluated resistive index at baseline and after vasodilation induced by nitroglycerine in normoalbuminuric patients with type 2 diabetes or essential hypertension, relating the values to indices of systemic vascular dysfunction. METHODS: Newly diagnosed treatment-naïve type 2 diabetic (n = 32) and hypertensive patients (n = 49) were compared with 27 age- and sex-matched healthy controls. Renal resistive index was obtained by duplex ultrasound at baseline and after 25 µg sublingual nitroglycerine. Endothelium-dependent (flow-mediated dilation) and -independent (response to nitroglycerine) vasodilation in the brachial artery was assessed by computerised edge detection system. Carotid-femoral pulse-wave velocity and augmentation index were assessed by applanation tonometry. Nitrotyrosine levels, an index of oxidative stress, were also measured. RESULTS: Resistive index was higher in diabetic than in hypertensive patients and controls (p < 0.001), while changes in resistive index induced by nitroglycerine were lower in hypertensive patients compared with controls (p < 0.01), and were further reduced in type 2 diabetic patients. Hypertensive and diabetic patients showed significantly increased arterial stiffness, nitrotyrosine levels and reduced endothelial function than controls (p < 0.05). Changes in resistive index induced by nitroglycerine were independently related to serum glucose, reactive hyperaemia and aortic pulse-wave velocity in the overall population. CONCLUSIONS/INTERPRETATION: These results support the dynamic evaluation of renal resistive index as an early detector of renal vascular alterations in the presence of type 2 diabetes and hypertension, even before the onset of microalbuminuria.


Subject(s)
Albuminuria/physiopathology , Diabetes Mellitus, Type 2/physiopathology , Hypertension/physiopathology , Kidney/blood supply , Regional Blood Flow/physiology , Adult , Albuminuria/blood , Albuminuria/epidemiology , Blood Glucose/metabolism , Case-Control Studies , Comorbidity , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/epidemiology , Female , Humans , Hypertension/blood , Hypertension/epidemiology , Kidney/diagnostic imaging , Male , Middle Aged , Nitroglycerin/pharmacology , Oxidative Stress/physiology , Tyrosine/analogs & derivatives , Tyrosine/blood , Ultrasonography , Vasodilation/drug effects , Vasodilation/physiology , Vasodilator Agents/pharmacology
16.
J Hum Hypertens ; 23(12): 801-7, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19339995

ABSTRACT

The predisposition to thrombogenesis is increased in essential hypertension, and hypertensive patients are prone to develop more vulnerable atherosclerotic plaques. To evaluate the possible influence of family history of hypertension on some indicators of early atherosclerosis, we studied eighty-five healthy normotensive individuals with (FH+) or without (FH-) family history of essential hypertension by measuring metabolic profile and concentrations of P-selectin, interleukin 6 and matrix metalloproteinase (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1. In a subset of individuals, MMP-9 activity was assessed in monocytes by zymography, and TIMP-1 expression by western blot. As compared with FH- individuals, FH+ individuals had significantly higher P-selectin but similar interleukin-6 levels. Although no difference was observed in MMP-2 levels between the two groups, MMP-9 and TIMP-1 were higher in FH+ individuals, who also had higher intracellular MMP-9 levels and TIMP-1 protein expression. P-selectin (r=-0.32; P<0.01), MMP-9 (r=-0.37; P<0.001) and TIMP-1 (r=-0.23; P<0.05) levels were inversely related to high density lipoprotein (HDL) cholesterol. P-selectin was also directly related to serum triglycerides (r=0.30; P<0.01). We conclude that a positive family history of hypertension is associated with an initial increase in markers of inflammation and plaque instability in otherwise healthy young normotensive individuals, likely conveying a predisposition to develop early atherothrombosis.


Subject(s)
Atherosclerosis/epidemiology , Atherosclerosis/genetics , Family Health , Hypertension/epidemiology , Hypertension/genetics , Adult , Atherosclerosis/blood , Biomarkers/blood , Blood Pressure , Female , Humans , Hypertension/blood , Interleukin-6/blood , Lipoproteins, LDL/blood , Male , Matrix Metalloproteinase 2/blood , Matrix Metalloproteinase 9/blood , P-Selectin/blood , Prevalence , Risk Factors , Tissue Inhibitor of Metalloproteinase-1/blood , Young Adult
17.
Horm Metab Res ; 41(7): 568-72, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19322745

ABSTRACT

Some cytokines and proinflammatory mediators are considered markers of increased atherothrombotic risk. Few information is available on the effects of acute glucose and insulin variations on these markers of atherosclerosis. We assessed the acute effect of glucose and insulin on soluble CD40 ligand (sCD40L), IL-6, and P-selectin levels, evaluating their relationship with insulin sensitivity in normal glucose tolerance subjects (NGT). Twenty-four NGT subjects underwent a 3-h oral glucose tolerance test (OGTT) with measurements of sCD40L, IL-6, and P-selectin levels at 0, 90 and 180 min. Insulin sensitivity was assessed by the Oral Glucose Sensitivity Index (OGIS). To distinguish the role of glucose and insulin, eight subjects had the plasma glucose profile of the OGTT reproduced by a variable IV glucose infusion (ISO-G study) and nine underwent a euglycemic clamp. Lastly, a 3-h time-control (TC) study was performed in eleven subjects. A significant reduction of sCD40L was observed during OGTT and ISO-G study. This reduction was not due to time-related changes, since it was not observed in TC study. During the clamp, insulin induced a marked drop in sCD40L (from 4.89+/-1.34 to 1.60+/-0.29 ng/ml, p<0.05). In the pooled data from all studies, fasting sCD40L was indirectly related to LDL-cholesterol (r=-0.38; p=0.04), while IL-6 was directly related with BMI, fat mass, waist circumference, and P-selectin (p<0.05). sCD40L levels are downregulated during a short-term period of acute hyperinsulinemia, whether induced by oral or intravenous glucose administration or by insulin infusion, while it does not seem to affect P-selectin and IL-6.


Subject(s)
Fibrinolytic Agents/blood , Hyperinsulinism/blood , Adult , Blood Glucose , CD40 Ligand/blood , Glucose/administration & dosage , Glucose/metabolism , Glucose Tolerance Test , Humans , Hyperinsulinism/complications , Hyperinsulinism/immunology , Hyperinsulinism/metabolism , Inflammation Mediators/blood , Insulin/administration & dosage , Interleukin-6/blood , Male , P-Selectin/blood
18.
J Endocrinol Invest ; 31(7): 660-5, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18787388

ABSTRACT

Hypercholesterolemia and Type 2 diabetes are well-recognized risk factors for cardiovascular disease, promoted by a condition of subclinical inflammation and a hypercoagulable state. Soluble CD40 ligand (sCD40L), a marker of vascular inflammation, seems to predict vascular damage in patients with Type 2 diabetes. Beside the lipid-lowering effect, statins seem to slow the progression of atherosclerosis through a series of anti-inflammatory effects, including a reduction of sCD40L levels. This study compared the effect of a short-term (12 weeks) treatment with rosuvastatin or simvastatin on some markers of inflammation in 36 patients with Type 2 diabetes and moderate hypercholesterolemia. As expected, both drugs significantly modified lipid profile; moreover, rosuvastatin and simvastatin were both able to significantly reduce albumin excretion rate in these patients, without affecting urinary N-acetyl-beta-D-glucosaminidase. Serum homocysteine was not influenced by the treatment, as interleukin-6 levels, while C reactive protein diminished; moreover, rosuvastatin, but not simvastatin, was able to significantly reduce sCD40L. The only clinical parameter related with the variations in sCD40L was systolic blood pressure. In hypercholesterolemic Type 2 diabetic patients, sCD40L, a factor playing a pivotal role in the pathogenesis of atherosclerosis and associated with more rupture-prone lesions, is reduced by short-term treatment with rosuvastatin.


Subject(s)
CD40 Ligand/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Fluorobenzenes/therapeutic use , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hypercholesterolemia , Pyrimidines/therapeutic use , Simvastatin/therapeutic use , Sulfonamides/therapeutic use , Albumins/metabolism , Biomarkers/metabolism , Blood Pressure , Diabetes Mellitus, Type 2/pathology , Female , Homocysteine/blood , Humans , Hypercholesterolemia/blood , Hypercholesterolemia/drug therapy , Interleukin-6/blood , Lipids/blood , Male , Middle Aged , Rosuvastatin Calcium
19.
Diabetologia ; 51(11): 2117-25, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18751966

ABSTRACT

AIMS/HYPOTHESIS: Inflammation is a mechanism of glomerular damage in chronic glomerulopathies. LDL may increase the production of inflammatory cytokines in renal tissues. However, the relative role of native, oxidised and glycated LDL in promoting this process has been only partially elucidated. METHODS: We tested the inflammatory and proapoptotic effects of native, oxidised and glycated LDL in human mesangial cells (HMCs) by measuring levels of IL6, CD40 and macrophage migration inhibitory factor (MIF) genes, MIF protein, release of IL6, soluble CD40, fibronectin and laminin, early and late apoptosis, and extracellular regulated kinases (ERK) 1/2 and c-Jun N-terminal kinase (JNK) activation. RESULTS: IL6 and CD40 mRNA were dose-dependently upregulated by all three species; this was closely paralleled by their increased release. MIF mRNA was potently stimulated by modified LDL, as confirmed by immunostaining. Fibronectin and laminin release was stimulated by both oxidised and glycated, but not native, LDL. All LDL species induced some increase in late, but not early, apoptosis, and similarly activated JNK2/3 phosphorylation; in contrast, ERK1/2 phosphorylation was more strongly upregulated by oxidised than either native or glycated LDL. CONCLUSIONS: In HMCs, the production and release of IL6 and CD40 is stimulated by both native and modified LDL, while MIF is more strongly stimulated by oxidised LDL. Regarding the pattern of mesangial expansion, fibronectin and laminin are upregulated by oxidised and glycated LDL. Apoptosis, if modest, is induced by all species. Intracellular signalling of native and modified LDL involves JNK2/3 and, perhaps more specifically, ERK1/2. Tight control of the lipid profile may be useful in preserving kidney function in patients with metabolic alterations.


Subject(s)
Glomerular Mesangium/physiopathology , Inflammation/physiopathology , Lipoproteins, LDL/pharmacology , Antigens, CD/genetics , CD40 Antigens/genetics , Glomerular Mesangium/drug effects , Glycation End Products, Advanced , Humans , Interleukin-6/genetics , Lipoproteins, LDL/blood , Lipoproteins, LDL/isolation & purification , RNA, Messenger/drug effects , RNA, Messenger/genetics
20.
Phys Med Biol ; 52(13): 3931-48, 2007 Jul 07.
Article in English | MEDLINE | ID: mdl-17664586

ABSTRACT

The energy dependence of the radiochromic film (RCF) response to beta-emitting sources was studied by dose theoretical calculations, employing the MCNP4C and EGSnrc/BEAMnrc Monte Carlo codes. Irradiations with virtual monochromatic electron sources, electron and photon clinical beams, a (32)P intravascular brachytherapy (IVB) source and other beta-emitting radioisotopes ((188)Re, (90)Y, (90)Sr/(90)Y,(32)P) were simulated. The MD-55-2 and HS radiochromic films (RCFs) were considered, in a planar or cylindrical irradiation geometry, with water or polystyrene as the surrounding medium. For virtual monochromatic sources, a monotonic decrease with energy of the dose absorbed to the film, with respect to that absorbed to the surrounding medium, was evidenced. Considering the IVB (32)P source and the MD-55-2 in a cylindrical geometry, the calibration with a 6 MeV electron beam would yield dose underestimations from 14 to 23%, increasing the source-to-film radial distance from 1 to 6 mm. For the planar beta-emitting sources in water, calibrations with photon or electron clinical beams would yield dose underestimations between 5 and 12%. Calibrating the RCF with (90)Sr/(90)Y, the MD-55-2 would yield dose underestimations between 3 and 5% for (32)P and discrepancies within +/-2% for (188)Re and (90)Y, whereas for the HS the dose underestimation would reach 4% with (188)Re and 6% with (32)P.


Subject(s)
Brachytherapy/methods , Radiotherapy Planning, Computer-Assisted/instrumentation , Radiotherapy Planning, Computer-Assisted/methods , Software , X-Ray Film , Beta Particles , Calibration , Electrons , Monte Carlo Method , Phantoms, Imaging , Photons , Polystyrenes/chemistry , Radiometry , Radiotherapy Dosage , Water/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...