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1.
Rev. Soc. Cardiol. Estado de Säo Paulo ; 33(2B): 99-99, abr. 2023. ilus.
Article in Portuguese | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1437768

ABSTRACT

INTRODUÇÃO: Dados de estudos randomizados avaliando os efeitos a longo prazo da cirurgia bariátrica no controle e remissão da hipertensão (HTN) são escassos. O seguimento de curto e médio prazo do Estudo GATEWAY (1 e 3 anos) mostrou melhora significativa e remissão da hipertensão após a cirurgia bariátrica. Aqui, apresentamos os dados de acompanhamento de 5 anos deste estudo. MÉTODOS: Conduzimos um ensaio clínico randomizado, em um centro único, fase III, paralelo e aberto. Pacientes com obesidade graus 1 e 2, tomando no mínimo 2 medicamentos anti-hipertensivos em doses máximas para hipertensão, foram alocados aleatoriamente para Bypass gástrico em Y de Roux (RYGB) combinado com tratamento clínico (TC) ou TC (estilo de vida/aconselhamento nutricional) isoladamente. O desfecho primário foi a redução de pelo menos 30% do total de anti-hipertensivos, mantendo níveis controlados de pressão arterial (PA) <140/90mmHg. A análise principal seguiu o princípio de intenção de tratar modificada e os valores ausentes foram imputados com a técnica de imputação múltipla. Os desfechos secundários incluíram vários biomarcadores. RESULTADOS: Foram incluídos 100 pacientes (76% mulheres, idade: 43,8±9,2 anos, índice de massa corporal, IMC: 36,9±2,7Kg/ m2). Após 5 anos, o IMC foi de 27,8±3,8kg/m2 para RYGB e 36,4±3,9kg/m2 para TC (P<0,001). A análise de sensibilidade considerando apenas os casos com seguimento concluído (n=69) revelou resultados consistentes. Os desfechos secundários nos grupos RYGB e TC, aos 60 meses, foram: circunferência abdominal 88,05 ± 9,84cm e 109,44 ± 9,76cm (P<0,001) ; hemoglobina glicada 5,4 ± 0,43% e 5,96 ± 0,9% (P<0,001); insulina 6,41 ± 2,46mU/L e 24,65 ± 16,57mU/L (P<0,001); LDL colesterol 93.61 ± 31.06mg/dL e 109.94 ± 37.58mg/dL (P=0,022); triglicerídeos 86,76 ± 38,45mg/dL e 140,33 ± 59,11 mg/dL (P<0,001); proteína C reativa de alta sensibilidade 0,81 ± 0,76mg/L e 6,13 ± 6,22mg/L (P=0,005), respectivamente. CONCLUSÕES: A cirurgia bariátrica é uma estratégia eficaz e duradoura no controle da PA com menor número ou nenhum medicamento anti-hipertensivo e na melhora do perfil metabólico e inflamatório em pacientes com obesidade graus 1 ou 2 e hipertensão.

2.
Oper Dent ; 39(1): 15-21, 2014.
Article in English | MEDLINE | ID: mdl-23675740

ABSTRACT

Detailed and accurate impressions are made when the oral environment is dry during the impression process. Maintaining a dry field on medically, physically, or emotionally compromised patients can be very challenging. If not achieved, it may compromise dental care and accurate outcomes. This article describes a technique that can be used to make a final impression for an indirect restoration in a protected, isolated, and dry environment, using a dry field illuminator.


Subject(s)
Dental Impression Technique , Dental Restoration, Permanent/methods , Crowns , Dental Impression Materials , Humans , Male , Mastication/physiology , Middle Aged , Osteoarthritis/complications
3.
G Chir ; 34(5-6): 161-3, 2013.
Article in English | MEDLINE | ID: mdl-23837954

ABSTRACT

Hamartoma is a benign tumor-like malformation characterized by a focal mixture of mature cells and tissues normally present in affected area. The hamartoma of the breast is rare. We report a case in an asymptomatic young woman coming to our attention for a left breast lesion detected by ultrasound screening.


Subject(s)
Breast Diseases , Hamartoma , Adult , Breast Diseases/diagnosis , Female , Hamartoma/diagnosis , Humans
4.
Clin Ter ; 162(2): e27-34, 2011.
Article in English | MEDLINE | ID: mdl-21533306

ABSTRACT

OBJECTIVES: The clinical diagnosis of synovial lesions is difficult and radiographic findings may establish a confident diagnosis only in some cases. MR imaging has become the technique of choice in evaluating these lesions, because a presumptive diagnosis can be made in most cases. The purpose of this study was to evaluate the joint synovial disease through intravenous contrast MRI examination and the following histological validation. MATERIALS AND METHODS: Forty-eight patients were considered, twenty-seven women and twenty-one men, with pain relief or collectively determined by a known joint synovial disease, who underwent MRI at our institution between 2000 and the second half of 2010. All patients underwent magnetic resonance imaging using a low field magnet (0.2 Tesla) or high field magnet (1,5Tesla). RESULTS: Only nine patients were diagnosed with an inflammatory arthropathy, in the remaining cases non-inflammatory arthropathy of which the most frequent form was pigmented villonodular synovitis (PVNS) was diagnosed. CONCLUSIONS: MRI is able to provide an accurate representation of all the pathological changes involved in the joint space following acute or chronic inflammation and to define the characteristic features useful in differential diagnosis.


Subject(s)
Joint Diseases/pathology , Magnetic Resonance Imaging , Synovial Membrane/pathology , Female , Humans , Male , Musculoskeletal System/pathology
5.
J Ultrasound ; 14(1): 37-9, 2011 Mar.
Article in English | MEDLINE | ID: mdl-23396659

ABSTRACT

Giant cell tumor of the tendon sheath (GCTTS) is a benign proliferative lesion of synovial origin that may affect the joints, bursae and tendon sheaths. We report the case of a giant cell tumor of the tendon sheath arising from the carpal tunnel of the wrist in a 47-year-old woman. The patient underwent ultrasound (US) examination and subsequently magnetic resonance imaging (MRI).

6.
J Ultrasound ; 14(3): 167-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-23396820

ABSTRACT

Pigmented villonodular synovitis (PVNS) is characterized by hyperplasia of the synovial tissue in joints, of tendon sheaths, and of the mucous membranes, or fibrous tissue adjacent to the tendons. Its etiology is unknown. We report a case of diffuse intra-articular PVNS of the right knee in a 38-year-old man. Ultrasound and magnetic resonance imaging (MRI) features of the disease are described.

7.
J Ultrasound ; 14(3): 113-21, 2011 Sep.
Article in English | MEDLINE | ID: mdl-23396957

ABSTRACT

Breast augmentation and breast reconstruction are increasingly common operations. All radiologists need to be able to recognize the normal appearances of the more commonly used implants on various imaging modalities and breast radiologists in particular are facing new challenges when imaging the women involved. This work aims to review the normal and abnormal findings in women undergoing breast implant surgery using ultrasonography, mammography, and magnetic resonance imaging.

9.
G Chir ; 30(1-2): 36-40, 2009.
Article in Italian | MEDLINE | ID: mdl-19272231

ABSTRACT

Cancer of supernumerary breast or ectopic breast tissue has haigher incidence than the cancer on ortotopic breast. This finding puts some problems about the diagnosis and therapy of ectopic breast cancer. The Authors describe their personal experience in three patients surgically treated and discuss about problems and solutions of this pathology.


Subject(s)
Axilla/pathology , Breast , Carcinoma, Ductal, Breast/diagnosis , Carcinoma, Ductal, Breast/surgery , Choristoma/pathology , Soft Tissue Neoplasms/diagnosis , Soft Tissue Neoplasms/surgery , Thoracic Wall/pathology , Adult , Aged , Axilla/surgery , Biomarkers, Tumor/analysis , Calcinosis/diagnostic imaging , Calcinosis/pathology , Carcinoma, Ductal, Breast/chemistry , Choristoma/surgery , Female , Humans , Mammography , Middle Aged , Palpation , Soft Tissue Neoplasms/chemistry , Soft Tissue Neoplasms/pathology , Thoracic Wall/surgery
10.
Radiol Med ; 114(1): 52-69, 2009 Feb.
Article in English, Italian | MEDLINE | ID: mdl-19082785

ABSTRACT

PURPOSE: This study was conducted to evaluate the role of computed tomography cystography (CTC) and virtual cystoscopy (VC) with 64-slice CT in diagnosing bladder lesions using flexible cystoscopy as the reference standard. MATERIALS AND METHODS: Twenty-eight patients with suspected bladder cancer and ten patients who had undergone transurethral resection of the bladder were studied by CTC and VC in both the supine and prone positions after distending the bladder with air. The patient population was divided into three groups based on lesion size at flexible cystoscopy. Results of the CT study were compared with those of flexible cystoscopy. RESULTS: Flexible cystoscopy depicted 88 bladder lesions in the 38 patients examined. Sensitivity and specificity values of CTC and VC alone were constantly lower than those of the combined-approach (group 1: 93.10% and 92.31%; group 2: 100% and 100%; group 3: 100% and 100%, respectively). Receiver operating characteristic (ROC) curve analysis showed that the combined approach decreases the lower dimensional threshold for lesion detection (1.4 mm). CONCLUSIONS: VC and CTC with 64-slice CT are promising diagnostic techniques for bladder cancers measuring 1-5 mm. Further studies on larger patient populations are required to validate our results.


Subject(s)
Carcinoma, Transitional Cell/diagnostic imaging , Cystoscopy/methods , Tomography, Spiral Computed , Urinary Bladder Neoplasms/diagnostic imaging , Urinary Bladder/diagnostic imaging , Aged , Carcinoma, Transitional Cell/pathology , Data Interpretation, Statistical , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/diagnostic imaging , Observer Variation , Patient Selection , Prone Position , ROC Curve , Sensitivity and Specificity , Supine Position , Time Factors , Tomography, Spiral Computed/instrumentation , Tomography, Spiral Computed/methods , Urinary Bladder/pathology , Urinary Bladder Neoplasms/pathology
11.
G Chir ; 29(6-7): 281-4, 2008.
Article in Italian | MEDLINE | ID: mdl-18544265

ABSTRACT

By clinical observation and surgical treatment of a patient with cutaneous B-cell non-Hodgkin lymphoma, the Authors describe the nosological approach, the correct diagnosis and the surgical treatment in this disease.


Subject(s)
Lymphoma, B-Cell/diagnosis , Lymphoma, B-Cell/surgery , Skin Neoplasms/diagnosis , Skin Neoplasms/surgery , Humans , Male , Treatment Outcome
12.
Int J Pharm ; 325(1-2): 155-62, 2006 Nov 15.
Article in English | MEDLINE | ID: mdl-16884870

ABSTRACT

Polysaccharide-coated liposomes have been studied for their potential use for peptide drug delivery by the oral route because they are able to minimize the disruptive influences on peptide drugs of gastrointestinal fluids. The aim of this work was to synthesize and characterize a modified polysaccharide, O-palmitoylscleroglucan (PSCG), and to coat unilamellar liposomes for oral delivery of peptide drugs. To better evaluate the coating efficiency of PSCG, also scleroglucan (SCG)-coated liposomes were prepared. We studied the surface modification of liposomes and the SCG- and PSCG-coated liposomes were characterized in terms of size, shape, zeta potential, influence of polymer coating on bilayer fluidity, stability in serum, in simulated gastric and intestinal fluids and against sodium cholate and pancreatin. Leuprolide, a synthetic superpotent agonist of luteinizing hormone releasing hormone (LHRH) receptor, was chosen as a model peptide drug. After polymer coating the vesicle dimensions increased and the zeta potential shifted to less negative values. These results indicate that both SCG- and PSCG-coated liposomes surface and DSC results showed that PSCG was anchored on the liposomal surface. The stability of coated-liposomes in SGF, sodium cholate solution and pancreatin solution was increased. From this preliminary in vitro studies, it seems that PSCG-coated liposomes could be considered as a potential carrier for oral administration.


Subject(s)
Glucans/chemistry , Leuprolide/chemistry , Liposomes/chemistry , Animals , Cattle , Chemistry, Pharmaceutical , Drug Delivery Systems/methods , Drug Stability , Fertility Agents, Female/administration & dosage , Fertility Agents, Female/chemistry , Fertility Agents, Female/pharmacokinetics , Gastric Juice/chemistry , Gastric Juice/metabolism , Glucans/blood , Glucans/chemical synthesis , Intestinal Secretions/chemistry , Intestinal Secretions/metabolism , Leuprolide/administration & dosage , Leuprolide/pharmacokinetics , Lipid Bilayers/chemistry , Liposomes/blood , Liposomes/chemical synthesis , Magnetic Resonance Spectroscopy/methods , Nanotechnology/methods , Pancreatin/chemistry , Pancreatin/metabolism , Particle Size , Sodium Cholate/chemistry , Sodium Cholate/metabolism , Spectrophotometry, Infrared/methods , Static Electricity
13.
Eur J Pharm Sci ; 28(5): 385-93, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16797946

ABSTRACT

In this work, we report the preparation, the characterization and interaction with cells of novel pH-sensitive non-phospholipid vesicle formulations, from a non-ionic surfactant mixed with cholesterol (CHOL) and his derivative cholesteryl hemisuccinate (CHEMS), as pH-sensitive molecule. This molecule, can destabilize the vesicle lipid bilayer when exposed to an acidic environment, with a subsequent release of vesicular content, enhancing the cytoplasmatic delivery of drugs to target cells. Vesicles were characterized by static and dynamic light scattering, in order to evaluate their dimensions, bilayer thickness and vesicle stability. Membrane permeability changes were determined by the release of entrapped hydroxypyrene-1,3,6-trisulfonic acid (HPTS). Also diphenylhesatriene (DPH) fluorescence anisotropy and zeta potential measurements were used to evidence the pH sensitivity. Furthermore vesicles were characterized by means of electronic microscopy after freeze-fracture. The interaction of non-lipid vesicles containing different fluorescent dyes with Raw 264.7, mouse monocite macrophage, were analyzed by flow cytometric analysis. The obtained results indicate that the pH-sensitive vesicular structures show good plasma stability and relevant pH-sensitivity. Moreover this formulation was able to interact with target membranes (i.e. plasma or endosomal membrane) and to release the encapsulated material into the cytoplasm.


Subject(s)
Cholesterol/chemistry , Hydrogen-Ion Concentration , Macrophages/cytology , Surface-Active Agents/chemistry , Animals , Cell Line , Cholesterol/metabolism , Endocytosis , Fluorescent Dyes/chemistry , Freeze Fracturing , Mice , Microscopy, Electron, Transmission , Permeability , Phospholipids/chemistry , Phospholipids/metabolism , Plasma , Surface-Active Agents/metabolism
14.
J Pharm Biomed Anal ; 37(1): 73-9, 2005 Feb 07.
Article in English | MEDLINE | ID: mdl-15664745

ABSTRACT

The lipophilicity of some cardiovascular drugs was determined by capillary electrophoresis (CE). Mexiletine, amlodipine and indapamide, the drugs considered, were in contact with liposomial vescicles for 2, 4 or 6 h. After the contact time the drugs, penetrated into liposomial vesicles, were determined by CE using phosphate buffer (pH 6.3 or 7.4) or borate buffer (pH 9). The lipophilicity of three drugs was determined considering the drug percentage penetrated into liposomial vesicles. The found lipohilicity order was amlodipine > mexiletine > indapamide.


Subject(s)
Cardiovascular Agents/analysis , Liposomes/analysis , Chemistry, Pharmaceutical , Electrophoresis, Capillary/methods
15.
J Control Release ; 95(1): 67-74, 2004 Feb 20.
Article in English | MEDLINE | ID: mdl-15013233

ABSTRACT

In this paper, the experimental conditions for preparing ampicillin-loaded surfactant vesicles (SVs) are described. Our studies are focused on the potential use of a vesicular polymeric dispersion as ampicillin delivery system for topical application. The main components of the formulation are uncharged and charged SVs loaded with ampicillin and dispersed in a gellan solution. The following issues are addressed: the drug encapsulation efficiency (e.e.), the kinetic of drug release from the delivery systems, the antimicrobial activity of vesicle-entrapped ampicillin. The in vitro permeation experiments through a synthetic lipophilic barrier (Silastic) and through porcine skin are carried out to evaluate the potential use as a dermal formulation. The use of both a synthetic and a biological membrane allows to discriminate between the effects related to variations of thermodynamic parameters and those correlated to biological factors. The release rate of ampicillin is increased by encapsulation in neutral and negatively charged SVs and the permeation rate was slowed by dispersion of drug-loaded SVs in gellan solution. Finally, studies of antimicrobial activity on prepared systems evidenced that ampicillin encapsulated in SVs exhibit a higher activity than the free drug.


Subject(s)
Ampicillin/administration & dosage , Ampicillin/pharmacology , Penicillins/administration & dosage , Penicillins/pharmacology , Administration, Topical , Algorithms , Animals , Chromatography, High Pressure Liquid , Dimethylpolysiloxanes , Drug Delivery Systems , Electrochemistry , Freeze Fracturing , In Vitro Techniques , Light , Membranes, Artificial , Particle Size , Permeability , Scattering, Radiation , Silicones , Skin Absorption , Swine , Thermodynamics
16.
J Pharm Biomed Anal ; 34(5): 921-31, 2004 Mar 10.
Article in English | MEDLINE | ID: mdl-15019026

ABSTRACT

Vitamin A is widely employed in pharmaceuticals and cosmetics. The all-trans (AT) isomer (100% of biological potency) is sensible to different factors, such as light, heat and formulation components, leading to its degradation or isomerization. The main objective of this work was to study, in model cosmetic lipophilic vehicles, the degradation of retinyl palmitate (RetP) to the less active cis-isomers in presence of widely used conservative agents (propyl gallate and Vitamin E). Two lipophilic phases were used (liquid paraffin and almond oil) because liquid paraffin, almost composed of satured hydrocarbons, is not degraded by light exposure, while almond oil, containing several double bonds, could interfere with light-induced degradative process of RetP. In the first phase, the more suitable analytical method was chosen between normal and reverse phase HPLC to follow the degradation of RetP. In the second phase, RetP light-induced degradation was studied to simulate storage condition effect on cosmetic products ageing. The results showed that: (a) the reverse phase HPLC technique, unable to separate the all-trans from the 13-cis and 9-cis isomers, derived by Vitamin A isomerization, leads to an incorrect quantitation of RetP; (b) the lipophilic vehicle influences the isomerization-degradation process; (c) the conservative agents do not protect from degradation.


Subject(s)
Light/adverse effects , Lipid Metabolism , Vitamin A/analogs & derivatives , Vitamin A/metabolism , Chemistry, Pharmaceutical , Diterpenes , Drug Carriers/analysis , Drug Carriers/metabolism , Lipids/analysis , Retinyl Esters , Vitamin A/analysis
17.
Int J Pharm ; 231(1): 21-32, 2002 Jan 01.
Article in English | MEDLINE | ID: mdl-11719010

ABSTRACT

Our research on topical application of lidocaine-loaded non-ionic surfactant vesicles (NSVs) was prompted by the great interest on new delivery systems for local anaesthetics. This study is focused on a novel formulation of NSVs entrapping lidocaine in the form of a free base (LID) and a hydrochloride (LIDHCl). NSVs were prepared from polyoxyethylene sorbitan monolaurate (Tween20) and cholesterol. The effect of vesicle composition and environmental pH condition (8.6-5.5) on drug encapsulation efficiency (e.e.) was investigated. Experimental strategies involved: freeze-fracture, microscopy technique, dynamic light scattering, permeation through Silastic and mouse abdominal skin, in vitro release kinetics of vesicle-entrapped drugs, fluorescence quenching analyses. Diffusion experiments showed that the flux of charged lidocaine through Silastic membrane was possible only after the vesicle encapsulation. Permeation through mouse abdominal skin of LIDHCl loaded vesicles showed a higher flux and a shorter lag time with respect to classical liposome formulations, while LID permeation rate was quite similar for NSV and liposome formulations. Vesicles were also prepared in the presence of dicetylphosphate (DCP) and N-cetylpyridinium chloride (CP) to obtain negatively and positively charged vesicles respectively, but in this case the e.e. of the drug was negligible. The possible reason of the remarkable lower e.e. observed with charged vesicles was investigated by means of fluorescence quenching experiments.


Subject(s)
Anesthetics, Local/chemistry , Lidocaine/chemistry , Lipid Bilayers/chemistry , Surface-Active Agents/chemistry , Anesthetics, Local/pharmacokinetics , Animals , Capsules , Diffusion , Drug Carriers , Hydrogen-Ion Concentration , Lidocaine/pharmacokinetics , Lipid Bilayers/pharmacokinetics , Male , Mice , Mice, Nude , Skin Absorption/physiology , Surface-Active Agents/pharmacokinetics
18.
J Periodontol ; 72(11): 1535-44, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11759865

ABSTRACT

BACKGROUND: Periodontitis is an inflammatory condition of tooth-supporting tissues that is usually treated by mechanical removal of plaque and microorganisms that adhere to teeth. This treatment, known as scaling and root planing, is not optimally effective. Adjunctive therapy with locally delivered antimicrobials has resulted in improved clinical outcomes such as probing depth reduction. This article reports on the efficacy and safety of locally administered microencapsulated minocycline. METHODS: Seven hundred forty-eight (748) patients with moderate to advanced periodontitis were enrolled in a multi-center trial and randomized to 1 of 3 treatment arms: 1) scaling and root planing (SRP) alone; 2) SRP plus vehicle; or 3) SRP plus minocycline microspheres. The primary outcome measure was probing depth reduction at 9 months. Clinical assessments were performed at baseline and 1, 3, 6, and 9 months. RESULTS: Minocycline microspheres plus scaling and root planing provided substantially more probing depth reduction than either SRP alone or SRP plus vehicle. The difference reached statistical significance after the first month and was maintained throughout the trial. The improved outcome was observed to be independent of patients' smoking status, age, gender, or baseline disease level. There was no difference in the incidence of adverse effects among treatment groups. CONCLUSIONS: Scaling and root planing plus minocycline microspheres is more effective than scaling and root planing alone in reducing probing depths in periodontitis patients.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Minocycline/therapeutic use , Periodontitis/drug therapy , Administration, Topical , Adult , Age Factors , Aged , Analysis of Variance , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Capsules , Combined Modality Therapy , Confidence Intervals , Dental Scaling , Female , Follow-Up Studies , Gingival Hemorrhage/drug therapy , Gingival Hemorrhage/therapy , Humans , Male , Microspheres , Middle Aged , Minocycline/administration & dosage , Minocycline/adverse effects , Odds Ratio , Periodontal Attachment Loss/drug therapy , Periodontal Attachment Loss/therapy , Periodontal Pocket/drug therapy , Periodontal Pocket/therapy , Periodontitis/therapy , Pharmaceutical Vehicles , Safety , Sex Factors , Smoking , Treatment Outcome
19.
J Control Release ; 60(2-3): 367-78, 1999 Aug 05.
Article in English | MEDLINE | ID: mdl-10425341

ABSTRACT

New hydrogels obtained by a crosslinking reaction between the polycarboxylated derivative of scleroglucan (sclerox) and 1, 6-hexanedibromide have been prepared and characterized. Different ratios between the alkane dihalide and sclerox yielded products with appreciably different properties. Water uptake by the hydrogel with a low degree of crosslinking was remarkably affected by ionic strength. The diffusion of a model molecule (theophylline) through the swelled crosslinked polymers was studied and the theoretical analysis leading to the calculation of permeability coefficients in different environmental conditions is reported. Tablets prepared with one of the new hydrogels behaved as swellable monolithic systems suitable for sustained drug release.


Subject(s)
Delayed-Action Preparations/pharmacokinetics , Glucans/chemistry , Hydrogels/chemistry , Hydrogels/chemical synthesis , Theophylline/pharmacokinetics , Bromides/chemistry , Cross-Linking Reagents/chemistry , Diffusion , Hydrogen-Ion Concentration , In Vitro Techniques , Osmolar Concentration , Permeability , Statistics as Topic , Tablets , Vasodilator Agents/pharmacokinetics
20.
Biotech Histochem ; 74(2): 77-84, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10333404

ABSTRACT

We analyzed the binding and fusogenic properties of surfactant vesicles (SVs), composed of ionic and nonionic surfactants and cholesterol, with the surface of different human lymphoid cells. The influence of charge on SVs-cell interaction was evaluated by monitoring the presence of fluorescent sodium calcein artificially entrapped in the vesicles using optical fluorescence microscopy and laser scanning confocal microscopy. Our results clearly indicate that only negatively charged vesicles bind and fuse with the plasma membrane of human lymphoid cells, and the number of SVs bound to the cell surface was variable among the positive cells. Thin section electron microscopy illustrated that the fusogenic events of SVs with the cell plasma membrane mostly occurred at smooth and nonvillous regions of the cell surface. Taken together, our results suggest that binding and fusion of SVs with the cell plasma membrane might be dependent on interactions with specific membrane components that preferentially recognize negatively charged SVs.


Subject(s)
Membrane Fusion/physiology , Polysorbates/metabolism , Surface-Active Agents/metabolism , Cholesterol/metabolism , Humans , Liposomes , Tumor Cells, Cultured
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