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1.
Phys Med Biol ; 68(14)2023 07 05.
Article in English | MEDLINE | ID: mdl-37321258

ABSTRACT

Objective. Respiration negatively affects the outcome of a radiation therapy treatment, with potentially severe effects especially in particle therapy (PT). If compensation strategies are not applied, accuracy cannot be achieved. To support the clinical practice based on 4D computed tomography (CT), 4D magnetic resonance imaging (MRI) acquisitions can be exploited. The purpose of this study was to validate a method for virtual 4DCT generation from 4DMRI data for lung cancers on a porcine lung phantom, and to apply it to lung cancer patients in PT.Approach. Deformable image registration was used to register each respiratory phase of the 4DMRI to a reference phase. Then, a static 3DCT was registered to this reference MR image set, and the virtual 4DCT was generated by warping the registered CT according to previously obtained deformation fields. The method was validated on a physical phantom for which a ground truth 4DCT was available and tested on lung tumor patients, treated with gated PT at end-exhale, by comparing the virtual 4DCT with a re-evaluation 4DCT. The geometric and dosimetric evaluation was performed for both proton and carbon ion treatment plans.Main results. The phantom validation exhibited a geometrical accuracy within the maximum resolution of the MRI and mean dose deviations, with respect to the prescription dose, up to 3.2% for targetD95%, with a mean gamma pass rate of 98%. For patients, the virtual and re-evaluation 4DCTs showed good correspondence, with errors on targetD95%up to 2% within the gating window. For one patient, dose variations up to 10% at end-exhale were observed due to relevant inter-fraction anatomo-pathological changes that occurred between the planning and re-evaluation CTs.Significance. Results obtained on phantom data showed that the virtual 4DCT method was accurate, allowing its application on patient data for testing within a clinical scenario.


Subject(s)
Four-Dimensional Computed Tomography , Lung Neoplasms , Animals , Swine , Four-Dimensional Computed Tomography/methods , Radiotherapy Planning, Computer-Assisted/methods , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/radiotherapy , Respiration , Radiometry/methods
2.
J Endocrinol Invest ; 46(10): 2079-2093, 2023 Oct.
Article in English | MEDLINE | ID: mdl-36933170

ABSTRACT

PURPOSE: Radioiodine I-131 (RAI) is the therapy of choice for differentiated thyroid cancer (DTC). Between 5% and 15% of DTC patients become RAI refractory, due to the loss of expression/function of iodide metabolism components, especially the Na/I symporter (NIS). We searched for a miRNA profile associated with RAI-refractory DTC to identify novel biomarkers that could be potential targets for redifferentiation therapy. METHODS: We analyzed the expression of 754 miRNAs in 26 DTC tissues: 12 responsive (R) and 14 non-responsive (NR) to RAI therapy. We identified 15 dysregulated miRNAs: 14 were upregulated, while only one (miR-139-5p) was downregulated in NR vs. R tumors. We investigated the role of miR-139-5p in iodine uptake metabolism. We overexpressed miR-139-5p in two primary and five immortalized thyroid cancer cell lines, and we analyzed the transcript and protein levels of NIS and its activation through iodine uptake assay and subcellular protein localization. RESULTS: The finding of higher intracellular iodine levels and increased cell membrane protein localization in miR-139-5p overexpressing cells supports the role of this miRNA in the regulation of NIS function. CONCLUSIONS: Our study provides evidence of miR-139-5p involvement in iodine uptake metabolism and suggests its possible role as a therapeutic target in restoring iodine uptake in RAI-refractory DTC.


Subject(s)
Iodine , MicroRNAs , Symporters , Thyroid Neoplasms , Humans , Iodine Radioisotopes/therapeutic use , Thyroid Neoplasms/genetics , Thyroid Neoplasms/radiotherapy , Thyroid Neoplasms/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Symporters/genetics
3.
J Endocrinol Invest ; 45(11): 2139-2147, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35792999

ABSTRACT

OBJECTIVE: Parathyroid scintigraphy is mandatory for the identification of hyperfunctioning parathyroid glands in hyperparathyroidism (HPT). The use of 99mTc-methoxy-isobutyl-isonitrile (MIBI) as radiopharmaceutical for parathyroid scintigraphy is considered the most valid and useful considering its uptake mechanism. Several MIBI-based radiopharmaceuticals are commercially available (i.e., MediMIBI, TechneMIBI, Stamicis). They seem to have similar physico-chemical characteristics and the choice between them is based on commercial criteria, even though some differences in qualitative scintigraphic results have been appreciated. Aims of the study were: first, to compare the scintigraphic quantitative data of MediMIBI, TechneMIBI, and Stamicis, particularly in the view of a personalized medicine approach; second, to investigate the potential effect of clinical-laboratory data on image quality using one of these radiopharmaceuticals. METHODS: Patients with diagnosis of HPT, who underwent a parathyroid scintigraphy using one of the three MIBI-based radiopharmaceuticals between December 2018 and October 2020, have been retrospectively identified. Parameters derived from regions of interest (ROIs) drawn on three different sites were obtained: a reasonable parathyroid lesion detected, an area in the lateral neck considered as the background, and the hepatic dome as the site of MIBI physiological uptake. Laboratory and clinical data, such as serum calcium, PTH, vitamin D, and creatinine levels, as well as possible drug-mediated interferences were considered. RESULTS: Among 250 patients included, 83 (33.2%) had the parathyroid scintigraphy using MediMIBI, 84 (33.6%) using TechneMIBI and 83 (33.2%) using Stamicis. The ROIs on the parathyroid uptake at early images, on the background, and on the hepatic dome were statistically different among the three groups (p < 0.05). No significant differences were found in the remaining semi-quantitative parameters among the three groups, not even considering clinical-laboratory data. CONCLUSIONS: Some differences in semi-quantitative parameters emerged among MIBI-based radiopharmaceuticals for parathyroid scintigraphy. This might justify the different qualitative scintigraphic results obtained using one or another of the cited radiopharmaceuticals.


Subject(s)
Hyperparathyroidism , Radiopharmaceuticals , Calcium , Creatinine , Humans , Hyperparathyroidism/diagnostic imaging , Parathyroid Glands/diagnostic imaging , Parathyroid Hormone , Radionuclide Imaging , Retrospective Studies , Technetium Tc 99m Sestamibi , Vitamin D
7.
Transl Med UniSa ; 15: 80-83, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27896231

ABSTRACT

T-large granular lymphocyte leukemia (T-LGLL) is a chronic clonal proliferation of effector memory cytotoxic CD3+CD57+CD56- T cells and the current guidelines suggest immunosuppressive therapy as first-line therapy, but the treatment of refractory/relapsed patients is still challenging due to the lack of prospective studies. We describe a series of two refractory/relapsed T-LGLL patients successfully treated with bendamustine, a chemotherapeutic agent largely used for B-cell neoplasms, but poorly investigated for the treatment of T-cell diseases. Complete remission (CR) was achieved in 3 and 6 months, respectively, and maintained for at least 20 months. One patient relapsed after a 20-month CR, but she was responsive to bendamustine therapy again, obtaining a further prolonged CR. Bendamustine as single agent or in combination could be a feasible therapeutic option in refractory/relapsed T-LGLL, especially for elderly patients because of its safety profile.

8.
AJNR Am J Neuroradiol ; 37(9): 1721-6, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27102310

ABSTRACT

BACKGROUND AND PURPOSE: In the past decades, a large body of work aimed at investigating brain structural anomalies accrued in autism spectrum disorder. Autism spectrum disorder is associated with intellectual disability in up to 50% of cases. However, only a few neuroimaging studies were conducted in autism spectrum disorder with intellectual disability, and none of them benefited from a nonsyndromic intellectual disability control group. MATERIALS AND METHODS: We performed a voxelwise investigation of the structural alterations in 25 children with autism spectrum disorder with intellectual disability by comparing them with 25 typically developing children and 25 nonsyndromic children with an intellectual disability. Besides a classic voxel-based morphometry statistical approach, the threshold-free cluster enhancement statistical approach was adopted. RESULTS: Classic voxel-based morphometry results did not survive family-wise error correction. The threshold-free cluster enhancement-based analysis corrected for family-wise error highlighted the following: 1) widespread focal cortical anomalies and corpus callosum alteration detected in autism spectrum disorder with intellectual disability; 2) basal ganglia and basal forebrain alteration detected both in autism spectrum disorder with intellectual disability and in nonsyndromic intellectual disability; and 3) differences in the frontocingulate-parietal cortex between autism spectrum disorder with intellectual disability and nonsyndromic intellectual disability. CONCLUSIONS: The present study suggests that the frontocingulate-parietal cortex may be the eligible key region for further investigations aiming at detecting imaging biomarkers in autism spectrum disorder with intellectual disability. The detection of structural alterations in neurodevelopmental disorders may be dramatically improved by using a threshold-free cluster enhancement statistical approach.


Subject(s)
Autism Spectrum Disorder/diagnostic imaging , Brain/diagnostic imaging , Intellectual Disability/diagnostic imaging , Autism Spectrum Disorder/psychology , Basal Ganglia/diagnostic imaging , Child , Child, Preschool , Cluster Analysis , Corpus Callosum/diagnostic imaging , Female , Humans , Image Processing, Computer-Assisted , Intellectual Disability/psychology , Intelligence Tests , Magnetic Resonance Imaging , Male , Neuropsychological Tests , Parietal Lobe/diagnostic imaging
9.
Transl Med UniSa ; 6: 2-10, 2013.
Article in English | MEDLINE | ID: mdl-24251241

ABSTRACT

Overwhelming post-splenectomy infection (OPSI) is a rare medical emergency, mainly caused by encapsulated bacteria, shortly progressing from a mild flu-like syndrome to a fulminant, potentially fatal, sepsis. The risk of OPSI is higher in children and in patients with underlying benign or malignant hematological disorders. We retrospectively assessed OPSI magnitude in a high risk cohort of 162 adult splenectomized patients with malignant (19%) and non malignant (81%) hematological diseases, over a 25-year period: 59 of them splenectomized after immunization against encapsulated bacteria, and 103, splenectomized in the previous 12-year study, receiving only life-long oral penicillin prophylaxis. The influence of splenectomy on the immune system, as well as the incidence, diagnosis, risk factors, preventive measures and management of OPSI are also outlined. OPSI occurred in 7 patients (4%) with a median age of 37 years at time interval from splenectomy ranging from 10 days to 12 years. All OPSIs occurred in non immunized patients, except one fatal Staphylococcus aureus -mediated OPSI in a patient adequately immunized before splenectomy. Our analysis further provides evidence that OPSI is a lifelong risk and that current immune prophylaxis significantly decreases OPSI development. Improvement in patients' education about long-term risk of OPSI and increased physician awareness to face a potentially lethal medical emergency, according to the current surviving sepsis guidelines, represent mandatory strategies for preventing and managing OPSI appropriately.

10.
Transl Med UniSa ; 5: 7-13, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23905076

ABSTRACT

Osteoporosis and avascular necrosis (AVN) are long-lasting and debilitating complications of hematopoietic stem cell transplantation (HSCT). We describe the magnitude of bone loss, AVN and impairment in osteogenic cell compartment following autologous (auto) and allogeneic (allo) HSCT, through the retrospective bone damage revaluation of 100 (50 auto- and 50 allo-HSCT) long-term survivors up to 15 years after transplant. Current treatment options for the management of these complications are also outlined. We found that auto- and allo-HSCT recipients show accelerated bone mineral loss and micro-architectural deterioration during the first years after transplant. Bone mass density (BMD) at the lumbar spine, but not at the femur neck, may improve in some patients after HSCT, suggesting more prolonged bone damage in cortical bone. Phalangeal BMD values remained low for even more years, suggesting persistent bone micro-architectural alterations after transplant. The incidence of AVN was higher in allo-HSCT recipients compared to auto-HSCT recipients. Steroid treatment length, but not its cumulative dose was associated with a higher incidence of bone loss. Allo-HSCT recipients affected by chronic graft versus host disease seem to be at greater risk of continuous bone loss and AVN development. Reduced BMD and higher incidence of AVN was partly related to a reduced regenerating capacity of the normal marrow osteogenic cell compartment. Our results suggest that all patients after auto-HSCT and allo-HSCT should be evaluated for their bone status and treated with anti-resorptive therapy as soon as abnormalities are detected.

11.
Infez Med ; 20 Suppl 2: 43-7, 2012.
Article in English | MEDLINE | ID: mdl-23042005

ABSTRACT

Mucormycosis is an increasingly recognized invasive fungal infection (IFI) in patients with acute myeloid leukemia (AML) and after allogeneic (allo) stem cell transplantation (HSCT); it is mainly due to the severe and prolonged neutropenia related to high-dose chemotherapy. In such patients, the lung is the most frequently involved site in mucormycosis. Since rapidly progressive dissemination may occur after pulmonary mucormycosis in hematologic malignancies, early diagnosis and prompt initiation of an effective antifungal therapy is mandatory for a successful outcome. We report the case of a young AML patient who developed, early after the onset of neutropenia in the first induction phase of chemotherapy, a rapidly progressive pulmonary IFI, successfully treated with liposomal Amphotericin-B (LAmB) and then with a limited open toracothomy biopsy, clearly establishing diagnosis of mucormycosis and removing lung infiltrate. Secondary prophylaxis with LamB, applied during both consolidation therapy and myeloablative sibling allogeneic HSCT, was effective to prevent IFI recurrence despite the development of grade I acute graft-versus-host disease (GVHD) and limited chronic GVHD requiring immunosuppressive treatment. Our case report further provide evidence that the combined surgical and LAmB therapy is an effective and safe choice for the management of pulmonary mucormycosis in hematological immunocompromised patients.


Subject(s)
Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Lung Diseases, Fungal/drug therapy , Lung Diseases, Fungal/surgery , Mucormycosis/drug therapy , Mucormycosis/surgery , Adult , Combined Modality Therapy , Humans , Male , Remission Induction
12.
Respir Med ; 101(6): 1155-62, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17280825

ABSTRACT

Atmospheric particulate matter (PM), an ingredient of urban pollution matter, is a mixture of solid and liquid particles differing in origin, dimension and composition. There is big concern about inhaled PM in urban areas, especially due to its adverse effects on the respiratory system. Diesel exhaust particulate (DEP), which constitutes the major part of PM, is characterized by a carbonic mixture composed of approximately 18,000 different high-molecular-weight organic compounds. Diesel engines release 10 times the amount of NO(2) aldehydes and breathable PM compared to unleaded gasoline engines and more than 100 times that produced by catalysed gasoline engines; these data gain great significance when taken into account the fact that diesel-powered vehicles are becoming more and more popular. DEP polyaromatic hydrocarbons (PAH), once deposited on airways mucous surfaces easily pass through epithelial cells (ECs) membranes, bind themselves to cytosolic receptors and then affect cell growth and differentiation. Human lung epithelial cells and macrophages engulf DEP, this resulting in increased proinflammatory cytokines release (IL-6, IL-8 and GM-CSF). We investigated the biological effects of DEP-PM on the human lung EC line A549. Light microscopy analysis suggested the presence of cell wall alterations, and provided evidence of PM internalization and cytoplasmic vacuolization. Following PM stimulation, nuclei also were seen undergo clear gross morphological modifications. Immunocytochemistry was used to detect intracytoplasmic IL-6 and IL-8 expression.


Subject(s)
Air Pollutants/pharmacology , Respiratory Mucosa/drug effects , Vehicle Emissions/toxicity , Air Pollutants/analysis , Cell Size/drug effects , Cytoplasm/immunology , Environmental Monitoring/methods , Epithelial Cells/drug effects , Epithelial Cells/immunology , Epithelial Cells/pathology , Humans , Interleukin-6/metabolism , Interleukin-8/metabolism , Particle Size , Particulate Matter/analysis , Particulate Matter/pharmacology , Respiratory Mucosa/immunology , Respiratory Mucosa/pathology , Tumor Cells, Cultured , Vehicle Emissions/analysis
13.
Brain Res Bull ; 56(3-4): 169-72, 2001.
Article in English | MEDLINE | ID: mdl-11719247

ABSTRACT

Transglutaminases (Enzyme Commission 2.3.2.13) are a large family of enzymes that show the common capacity to catalyze cross-linking of protein substrates. Some members of this family of enzymes are also capable of catalyzing other reactions important for the cell life. The distribution and the role of these enzymes have been widely studied in numerous cell types and tissues, but only recently their expression and functions started to be investigated in the central nervous system. One of the main biochemical properties of the transglutaminase enzymes is to form large protein aggregates that are insoluble in all known protein detergents, such as urea, guanidinium, and sodium dodecyl sulfate. Recently, the transglutaminase activity has been hypothesized to be involved in the pathogenetic mechanisms responsible for the formation of cellular inclusions present in Huntington disease and in all the other polyglutamine (polyQ) diseases hitherto identified, such as spinobulbar muscular atrophy or Kennedy disease, spinocerebellar ataxias (SCA-1, SCA-2, SCA-3 or Machado-Joseph disease, SCA-6 and SCA-7) and dentatorubropallidoluysian atrophy. In this review we describe the biochemical properties of the transglutaminase enzymes and some recent findings about the physiopathological roles played by these enzymes in the central nervous system.


Subject(s)
Muscular Atrophy, Spinal/metabolism , Peptides/genetics , Peptides/metabolism , Transglutaminases/metabolism , Trinucleotide Repeat Expansion , Brain/enzymology , Humans , Machado-Joseph Disease/genetics , Machado-Joseph Disease/metabolism , Muscular Atrophy, Spinal/genetics
14.
Am J Hematol ; 68(1): 1-3, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11559929

ABSTRACT

In the present study, beta-endorphin and met-enkephalin were tested for their antiplatelet activity in human platelet-rich plasma (PRP). Blood samples were obtained from 15 healthy subjects. The results of the study show that these two endogenous opioids (200 pg/ml final concentration) reduce platelet aggregation when it is induced by ADP at low dose (0.5 microM). It is likely due to conformational changes on the platelet membrane that cause a non-specific decreased susceptibility to platelet-aggregating agonists.


Subject(s)
Blood Platelets/drug effects , Enkephalin, Methionine/pharmacology , beta-Endorphin/pharmacology , Adenosine Diphosphate/pharmacology , Blood Platelets/physiology , Dose-Response Relationship, Drug , Humans , Osmolar Concentration , Platelet Aggregation/drug effects
15.
Diabetes Obes Metab ; 3(1): 33-40, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11213597

ABSTRACT

AIM: Non-insulin-dependent diabetes mellitus (type 2 diabetes) not responding to dietary treatment alone in patients with non-alcoholic liver cirrhosis is characterized by high postprandial hyperglycaemia. The control of postprandial hyperglycaemia in such patients, is generally achieved by the means of progressively higher doses of insulin, with an increasing risk of hypoglycaemia in the late postprandial period. The aim of this study was to evaluate the use of acarbose for the control of postprandial hyperglycaemia in 100 patients with well-compensated liver cirrhosis and type 2 diabetes treated with insulin. METHODS: The study was double blind with randomization of treatments into acarbose (52 patients) vs. placebo (48 patients) with parallel branches over a period of 28 weeks. RESULTS: All patients tolerated the treatments well and no significant variations in liver function tests were observed (< 5% vs. pretreatment). A significant reduction of several parameters was observed only after acarbose treatment: fasting glycaemia (173 +/- 28 vs. 146 +/- 19 mg/dl; p < 0.01), postprandial glycaemia (230 +/- 24 vs. 148 +/- 20 mg/dl; p < 0.01), mean glycaemia (206 +/- 20 vs. 136 +/- 13 mg/dl; p < 0.01), mean variation (180 +/- 14 vs. 51 +/- 10 mg/dl; p < 0.01), HbA1c (8.9 +/- 0.8 vs. 7.2 +/- 0.5; p < 0.05), C-peptide 2 h after a standard meal (4.5 +/- 1.9 vs. 2.8 +/- 1.7 ng/ml; p < 0.05), whereas the parameters did not change significantly after the placebo. After acarbose treatment a significant increase of intestinal voiding/week (+116% vs. +10%; p < 0.01) and a parallel reduction of blood ammonia levels (-52 +/- 9% vs. -9 +/- 5%; P < 0.01) were observed. CONCLUSIONS: The results clearly document the good tolerability and the absence of toxic effects of acarbose on liver, due to the lack of both intestinal absorption and hepatic metabolism of the drug at doses in the therapeutic range. In fact, acarbose increases the peristalsis movements of the gut, stimulates the proliferation of the saccarolytic bacteria and simultaneously reduces the proliferation of proteolytic bacteria, thus resulting active in the reduction of blood ammonia levels. These effects of acarbose may be advantageously exploited in the treatment of type 2 diabetic patients with well-compensated non-alcholic liver cirrhosis.


Subject(s)
Acarbose/therapeutic use , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Insulin/therapeutic use , Liver Cirrhosis/complications , Acarbose/administration & dosage , Acarbose/adverse effects , Ammonia/blood , Blood Glucose/metabolism , C-Peptide/blood , Double-Blind Method , Fasting , Female , Food , Glycated Hemoglobin/analysis , Humans , Insulin/administration & dosage , Male , Placebos
16.
Microsc Res Tech ; 51(5): 464-8, 2000 Dec 01.
Article in English | MEDLINE | ID: mdl-11074617

ABSTRACT

Sparse fluorescent pointlike subresolution objects have been imaged using a diffraction limited single-pinhole confocal fluorescence microscope. A Maximum likelihood image restoration algorithm has been used in conjunction with a measure of the experimental point spread function for improving the three-dimensional imaging of subresolution sparse objects. The experimental point-spread-function profiles have been improved by a factor of 1.95 in lateral direction and 3.75 in axial direction resulting in full-width half maximum (FWHM) values of 91 +/- 11 nm and 160 +/- 26 nm. This amounts to 1. 43 and 2.15 in optical units, respectively. The lateral and axial FWHM of the sparse pointlike subresolution objects is about 5 and 3 times smaller than the wavelength. This result points to the attractive possibility of utilising a compact confocal architecture for localising punctuate fluorescent objects having subresolution dimensions. The key resides in the utilisation of the measured point spread function coupled to an appropriate image restoration approach, and, of course, in the stability of the confocal system being used.


Subject(s)
Image Processing, Computer-Assisted , Microscopy, Confocal/methods , Algorithms , Cell Physiological Phenomena , Likelihood Functions , Microscopy, Fluorescence/methods
19.
Arch Ital Urol Androl ; 70(3 Suppl): 7-9, 1998 Jun.
Article in Italian | MEDLINE | ID: mdl-9707764

ABSTRACT

Between January 1988 and December 1995 48 orthotopic detubularized and reconfigured ileal neobladder were carried out with two distinct surgical procedures in the same Hospital. 33 underwent lower urinary tract reconstruction using Studer's technique with an afferent ileal tubular isoperistaltic segment; in 15 patients the ileal substitution of the bladder was performed with Paduan ileal bladder (VIP). In any case an ileal low pressure reservoir was obtained with similar functional capacity (400 ml. at the urodynamic control), as using the same length of ileum (40 cm) for the reconstruction of the reservoir itself. In order to other functional aspects (e.g. diurnal and nocturnal continence) results were analogous if a correct rehabilitation program was observed. Significant post-voiding residual and late neobladder decompensation was prevented with adequate mictional training. Early and late complications (globally 19-24%) were evaluated: strictures of ureteroileal and ileo-urethral anastomoses were rare; an ileoureteral reflux was observed at a cystographic control in 50% of Studer group, but never clinically significant and only in 20% of VIPs. No clinically significant metabolic changes were found. Survival was satisfactory at a mean follow-up of 48 months.


Subject(s)
Urinary Diversion/methods , Urinary Reservoirs, Continent , Adult , Aged , Cystectomy/rehabilitation , Evaluation Studies as Topic , Humans , Ileum/surgery , Male , Middle Aged , Neoplasm Seeding , Postoperative Complications , Survival Analysis , Urinary Bladder Neoplasms/mortality , Urinary Bladder Neoplasms/surgery
20.
Ital J Biochem ; 47(1): 13-8, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9646185

ABSTRACT

Modulation of neutrophil response to naturally occurring stimuli is important to avoid host tissue injure. Both soluble and particulate stimuli may induce superoxide anion generation in human polymorphonuclear leukocytes. Recently wortannin has been shown to inhibit the N-formyl-methionyl-leucyl-phenylalanine (fMLP) induced activation of respiratory burst via phosphatidylinositol 3-kinase. However no data are available about the effect of the inhibitor on the respiratory burst induced by a particulate stimulus. In this paper we studied the effect of wortmannin on E. coli induced respiratory burst and phagocytosis by flow cytometry, which allows the quantitation of both H2O2 production and ingested bacteria in whole blood samples without the need of purification and concomitant manipulation of the cells. The effects of worthmannin on fMLP-induced chemotaxis was also examined by the under agarose method. Neither the E. coli nor the fMLP-induced responses were blocked by wortmannin, suggesting that PI 3-kinase activity is not required to activate these neutrophil functions. Since it is known that the respiratory burst elicited by fMLP is blocked by wortmannin, our results suggest that the generation of oxygen radicals is controlled via different signal transduction pathways, depending on the agonist used.


Subject(s)
Androstadienes/pharmacology , Enzyme Inhibitors/pharmacology , Neutrophils/drug effects , Phagocytosis/drug effects , Phosphoinositide-3 Kinase Inhibitors , Cells, Cultured , Chemotaxis, Leukocyte/drug effects , Humans , Hydrogen Peroxide/metabolism , Neutrophils/metabolism , Respiratory Burst/drug effects , Wortmannin
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