Assuntos
Corticosteroides/uso terapêutico , Asma/complicações , Conjuntivite/complicações , Rinite Alérgica/tratamento farmacológico , Rinite/complicações , Adolescente , Asma/tratamento farmacológico , Criança , Feminino , Humanos , Rinite Alérgica/diagnóstico , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
IgG4 have been hypothesized to act as blocking antibodies capable of preventing IgE-mediated effector cell triggering. This study aims to evaluate the changes in IgG4 in children during a period of natural antigen avoidance. Serum IgE and IgG4 were evaluated in a group of asthmatic children, aged between 7 and 17 years, admitted to the residential house Istituto Pio XII (Misurina, BL, Italy), located at 1,756 m, in a natural model of antigen avoidance. All the patients were skin prick test positive to at least two of the following allergens: Dermatophagoides pteronissynus, Dermatophagoides farinae, cat epithelium, timothy grass pollen and Parietaria pollen. During the 180 days of hospitalization, serum specific IgE and IgG4 were measured six times. A significant decrease (p≤0.05) in serum specific IgE to house dust mite and pollen allergens was observed; by contrast, no significant variations were shown by IgG4 and IgG4/IgE ratio. No significant relationship was found between serum specific IgE, IgG4 and IgG4/IgE ratio variations and the re-exposure to house dust mite allergens during the Christmas holidays. A positive correlation between specific IgE and specific IgG4 was observed at each considered time (T0: r=0.57, p=0.08; T1: r=0.85, p=0.001; T3: r=0.76, p=0.01). The positive correlation between specific IgE and specific IgG4, enduring throughout the entire time of study, suggests a relationship between these classes of immunoglobulins.
Assuntos
Asma/imunologia , Asma/prevenção & controle , Ambiente Controlado , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Adolescente , Altitude , Animais , Antígenos de Dermatophagoides/imunologia , Antígenos de Plantas/imunologia , Asma/diagnóstico , Asma/fisiopatologia , Biomarcadores/sangue , Gatos , Criança , Feminino , Humanos , Exposição por Inalação , Testes Intradérmicos , Itália , Estudos Longitudinais , Pulmão/imunologia , Pulmão/fisiopatologia , Masculino , Parietaria/imunologia , Phleum/imunologia , Testes de Função Respiratória , Estações do Ano , Fatores de TempoRESUMO
Successful aerosol therapy depends mainly on targeting an adequate dose of drug to the appropriate receptors in the respiratory tract. Over the last years, major innovations have occurred in the delivery of inhaled drugs to the lungs. Despite the fact that more individuals suffer from rhinitis or sinusitis than from asthma or COPD, research into nasal delivery of aerosolized drugs remains scarce. Knowledge of the delivered dose, its regional distribution, and the manner in which drug targeting may be affected by nasal anatomy, air flow and disease condition is very important. Challenges to delivery of aerosolized medications to appropriate targets in the nasal cavity have been scarcely considered. A less-than-optimal technique can result in decreased delivery, reduced efficacy, increased risk of side-effects and high drug wasting. Knowledge of the actual dose and the site of deposition of the delivered drug would permit precise assessment of the relative performance of the delivery systems employed for a specific drug. Optimal physical aerosol characteristics and patient delivery profiles need to be definitively researched for each inhaled drug. There is a strong need to develop new engineered drug inhalation devices well-matched with improved drug formulations for the treatment of rhinitis or sinusitis.
Assuntos
Rinite/tratamento farmacológico , Sinusite/tratamento farmacológico , Administração por Inalação , Aerossóis , HumanosRESUMO
An unusual case of postaxial hexadactylism of the hands and feet in one female Caucasian neonate is described. The clinical picture was characterized by symmetrical duplication of the 5th finger in both hands and of the 4th finger in both feet. Malformations of the extremities both in the paternal and in the maternal family were reported. No other associated malformations have been found in the baby and her karyotype was normal. The performed analysis of the literature confirmed the peculiarity of the associated features of this case.
Assuntos
Dedos/anormalidades , Polidactilia/diagnóstico , Dedos do Pé/anormalidades , Feminino , Humanos , Recém-Nascido , Polidactilia/genéticaRESUMO
The aim of this study was to determine the output in-vitro of budesonide from two different nebulizers under simulated breathing conditions. The BimboNeb and Nebula nebulizers were used to nebulize 2 mL of budesonide (500 microg) suspension. Particle size was determined by inertial impaction after a 5-min nebulization. Total outputs of the drug from both nebulizers were measured using a sinus flow pump to create simulated breathing conditions. Paediatric and adult breathing patterns were used, with drug output measured after 5 and 10 min nebulization. The mass median aerodynamic diameter of budesonide using the BimboNeb (4.5 microm) was significantly greater than that from the Nebula (3.4 microm) (P<0.01). With the simulated adult breathing pattern, the total drug output after 5 min with the BimboNeb (61.5 microg) was twice that from the Nebula (30.7 microg). For the paediatric breathing pattern, total outputs were very similar for both nebulizers. In all cases, nebulizing for 10 min produced greater drug outputs compared with those after 5 min, particularly for the paediatric breathing pattern. The amount of aerosolized drug available for inhalation needs to be assessed for each nebuliser used and the effect of the patient's breathing pattern should also be taken into account.
Assuntos
Anti-Inflamatórios/química , Budesonida/química , Nebulizadores e Vaporizadores , Administração por Inalação , Adulto , Anti-Inflamatórios/administração & dosagem , Budesonida/administração & dosagem , Criança , Humanos , Tamanho da Partícula , Respiração , SuspensõesRESUMO
Steady state fluorescence anisotropy (rs) of TMA-DPH was measured to study the effect of respiratory burst activation with PMA, FMLP, and PAF on the physico-chemical structure of PMNs plasma membrane. Our results show a significant increase in rs during the respiratory burst activation. In the presence of NADPH-oxidase inhibitor DPI, only PAF induces changes in rs values. This suggests a non-specific effect of PAF on plasma membrane. Azide, which induces a supranormal release of H2O2, fails to increase the basal rs value after activation. Moreover, the catalase does not abolish the increase in rs induced upon activation. This rules out the possibility that changes of rs during the respiratory burst activation are attributed mainly to H2O2 release. We conclude that multiple processes accompanying the respiratory burst activation are responsible for the changes in the physico-chemical properties of PMNs plasma membrane.
Assuntos
Neutrófilos/metabolismo , Superóxidos/sangue , Adulto , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Difenilexatrieno/análogos & derivados , Corantes Fluorescentes , Humanos , Cinética , Luminescência , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Fator de Ativação de Plaquetas/farmacologia , Espectrometria de Fluorescência/métodos , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
Various alterations of red blood cell (RBC) plasma membrane appear both in diabetes mellitus and during the physiological aging process. Diabetes mellitus decreases RBC life-span; therefore, it may change the plasma membrane by acting through its effect on the aging process. In order to clarify the issue, RBCs from normal subjects and insulin-dependent diabetic patients were fractionated in five subpopulations of different mean age (fraction 1: early young RBC, fraction 5: mature RBC). Thereafter, plasma membranes were prepared and enzymatic activities, membrane fluidity and lipid peroxidation were evaluated. NA+, K(+)-ATPase activity decreased during aging and it was higher in all RBC subpopulations from normal subjects in comparison to diabetic patients. Next, lipid peroxidation and fluidity increased during aging in both the study groups; in this case, however, in all subpopulations, except for that from fraction 1, RBCs from diabetic patients showed higher membrane fluidity and lipid peroxidation in comparison to normal subjects. Data herein reported suggest that diabetes mellitus affects the plasma membrane independently of (lipid peroxidation and fluidity) or dependently on (Na+, K(+)-ATPase) its effect on aging. In the case of lipid peroxidation and fluidity diabetes mellitus seems to affect the membrane by decreasing RBC life span, whereas in the case of Na+K(+)-ATPase it seems to alter this enzymatic activity which in turn might affect RBC aging. Acetylcholinesterase activity decreased during aging in RBCs from normal subjects, but it increased in RBCs from diabetic patients; RBC subpopulation from fraction 1, on the other hand, showed similar values in normal subjects and diabetic patients. In this case the effect of diabetes mellitus appears only during aging.
Assuntos
Diabetes Mellitus Tipo 1/sangue , Envelhecimento Eritrocítico , Acetilcolinesterase/sangue , Adulto , Contagem de Eritrócitos , Membrana Eritrocítica/fisiologia , Eritrócitos/metabolismo , Feminino , Humanos , Peroxidação de Lipídeos , Masculino , Fluidez de Membrana , Pessoa de Meia-Idade , ATPase Trocadora de Sódio-Potássio/sangueRESUMO
Alterations in the functional activities of platelets (PLT) in type I diabetes have been widely observed. These changes play a key role in the development of cardiovascular complications in diabetes. Various functional activities of PLT are the result of the interaction of numerous stimuli with PLT plasma membrane. This study was designed to evaluate the oxidative response and membrane modifications of diabetic PLT stimulated by platelet activating factor (PAF). The oxidative response was assessed by employing luminol- and lucigenin-amplified chemiluminescence. Luminol-amplified chemiluminescence is sensitive to the release of hydrogen peroxide whereas lucigenin-amplified chemiluminescence is sensitive to the production of superoxide anion. Membrane fluidity and polarity were studied using fluorescence spectroscopy. Membrane fluidity was investigated by measuring steady-state fluorescence anisotropy of 1-[4-trimethylammonium-phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) and membrane polarity was studied by measuring the steady-state fluorescence emission and excitation spectra of 2-dimethylamino[6-lauroyl]-naphthalene (Laurdan). The diabetic group consisted of 20 type I diabetic children with good metabolic control. Our results show a significant decrease in the luminol- and lucigenin-amplified chemiluminescence of PAF stimulated PLT in the diabetic group with respect to controls. These data indicate a decrement in the release of reactive oxygen species by diabetic PLT. We observed a significant increase in steady-state fluorescence anisotropy of diabetic PLT membrane that reflects a decrease in membrane fluidity. Laurdan showed a blue shift of the fluorescence emission and excitation spectra in diabetic PLT with respect to the control group, indicating a decrease in membrane polarity. The addition of PAF to PLT induced a red shift of Laurdan spectra in both groups, indicating an increase in membrane polarity. Our study [table: see text] demonstrates an altered oxidative response to PAF stimulation of diabetic PLT, probably due to altered generation or handling of reactive oxygen species, and alterations in the physico-chemical properties of the plasma membrane which could influence various functional activities of PLT.
Assuntos
Plaquetas/fisiologia , Membrana Celular/fisiologia , Difenilexatrieno/análogos & derivados , Fator de Ativação de Plaquetas , Espécies Reativas de Oxigênio/metabolismo , Acridinas , Adolescente , Plaquetas/ultraestrutura , Criança , Feminino , Polarização de Fluorescência , Humanos , Peróxido de Hidrogênio/sangue , Cinética , Medições Luminescentes , Luminol , Masculino , Fluidez de Membrana , Espectrometria de Fluorescência , Superóxido Dismutase/sangue , Superóxidos/sangueRESUMO
The changes in plasma membrane polarity of polymorphonuclear leukocytes (PMN) during the activation of the respiratory burst were investigated by measuring the steady-state fluorescence emission spectra of 2-dimethylamino(6-lauroyl) naphthalene (Laurdan), which is known to be incorporated at the hydrophobic-hydrophilic interface of the bilayer, displaying spectral sensitivity to the polarity of its surroundings. Laurdan shows a marked steady-state emission blue shift in nonpolar solvents, with respect to polar solvents. Our results show a blue shift of the fluorescence emission spectra of Laurdan during activation of PMN with phorbol myristate acetate or N-formyl-methionyl-leucyl-phenylalanine. These results suggest that the activation of the respiratory burst of PMN is accompanied by a decrease in polarity in the hydrophobic-hydrophilic interface of the plasma membrane.
Assuntos
Membrana Celular/fisiologia , Neutrófilos/fisiologia , 2-Naftilamina/análogos & derivados , Membrana Celular/ultraestrutura , Corantes Fluorescentes , Humanos , Lauratos , Medições Luminescentes , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/ultraestrutura , Consumo de Oxigênio/efeitos dos fármacos , Espectrometria de Fluorescência/métodos , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
We investigated the ultrastructure of nasal cilia in 27 children suffering from recurrent infections of the upper respiratory tract, during and after the onset of an acute respiratory infection, and after a convalescent period of 12 weeks. Our results demonstrated that in seven subjects after resolution of infection, the morphology of a large proportion of the cilia (32%) was not back to normal. These findings suggest a long-term residual effect of infection, or the inability to reestablish normal ciliary structure during the convalescent period in some subjects with recurrent upper respiratory tract infection.
Assuntos
Nariz/ultraestrutura , Infecções Respiratórias/patologia , Doença Aguda , Estudos de Casos e Controles , Criança , Pré-Escolar , Cílios/fisiologia , Cílios/ultraestrutura , Feminino , Humanos , Masculino , Microscopia Eletrônica , Movimento , RecidivaRESUMO
Polymorphonuclear leukocytes (PMN) from diabetic subjects have been found to be abnormal in various functional activities. These activities are mediated by the plasma membrane. This study was designed to evaluate plasma membrane fluidity and polarity in children with type I diabetes mellitus using fluorescence spectroscopy. PMN membrane fluidity and polarity were assessed in a group of 32 diabetic children. Membrane fluidity was investigated by measuring steady-state fluorescence anisotropy and fluorescence decay of 1-[4-trimethylammonium-phenyl]-6-phenyl- 1,3,5-hexatriene (TMA-DPH), whereas membrane polarity was studied by measuring the steady-state fluorescence emission and excitation spectra of 2-dimethylamino[6-lauroyl]-naphthalene (Laurdan). TMA-DPH and Laurdan are known to be incorporated at the hydrophobic-hydrophilic interface of the bilayer. Our data show a significant increase in steady-state fluorescence anisotropy in diabetic PMN that reflects a decrease in membrane fluidity, and a decrease in TMA-DPH lifetime distribution indicating a decrease in membrane heterogeneity. Laurdan shows a blue shift of the fluorescence emission and a red shift of the excitation spectra in diabetic PMN with respect to the control group, indicating a decrease in membrane polarity. The results demonstrate a decrease in the phospholipid order at the membrane surface and a decrease in membrane polarity in diabetic PMN. These alterations in the physico-chemical properties of the plasma membrane could be the basis of the modifications in functional activities of PMN. The changes in the plasma membrane of PMN could be the result of metabolic and chemical modification associated with type I diabetes.
Assuntos
Diabetes Mellitus Tipo 1/sangue , Fluidez de Membrana , Neutrófilos/fisiologia , Adolescente , Membrana Celular/fisiologia , Membrana Celular/ultraestrutura , Polaridade Celular , Criança , Feminino , Polarização de Fluorescência , Humanos , Masculino , Neutrófilos/ultraestrutura , Espectrometria de FluorescênciaRESUMO
OBJECTIVE: To evaluate the anomalies of the central nervous system (CNS) by magnetic resonance imaging (MRI) in normal subjects and in syndromic patients. METHODS AND MATERIAL: Seventy-three normal subjects and 50 different syndromic patients with mental retardation (from 3 months to 16 years) were studied utilizing several morphometric parameters (degree of myelination of the white matter, evaluation of liquoral spaces, septo-caudate distance, Evans index, Aboulezz method, and length, width and angles of corpus callosum). RESULTS: A high frequency of anomalies of the corpus callosum, the Chiari anomaly and alterations either of the white matter or of the ventricular and periencephalic system have been observed. CONCLUSION: The authors point out the importance of cerebral MRI in the study of CNS in patients with malformation syndromes. The present research, carried out on a large number of both normal subjects and patients with malformation syndromes, represents one of the first systematic studies in this field.
Assuntos
Encéfalo/patologia , Deficiência Intelectual/patologia , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , SíndromeRESUMO
The effect of orally administered bacterial extracts given intermittently over 16 weeks on the bactericidal capacity of polymorphonuclear leucocytes (PMNs) in children with recurrent respiratory infections was investigated using a luminol-amplified chemiluminescence assay. Chemiluminescence of PMNs stimulated with zymosan or N-formyl-methionyl-leucyl-phenylalanine (fMLP) before and after treatment with bacterial extracts or intramuscular benzanthine penicillin was evaluated. Chemiluminescence induced by opsonized zymosan increased significantly (P less than 0.05) after treatment with bacterial extracts, whereas no significant changes were observed in the fMLP-stimulated PMNs. Long-acting penicillin treatment did not significantly affect zymosan- or fMLP-stimulated chemiluminescence. The data suggest that orally administered bacterial extracts can increase the opsonic capacity of serum and thus the bactericidal capacity of PMNs in subjects with recurrent respiratory infections.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Antígenos de Bactérias/imunologia , Neutrófilos/fisiologia , Infecções Respiratórias/imunologia , Administração Oral , Antibacterianos/uso terapêutico , Antígenos de Bactérias/administração & dosagem , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Recidiva , Infecções Respiratórias/prevenção & controleRESUMO
Neurocognitive dysfunction is one of the major complications of chronic renal failure (CRF). Uremic state during CRF encompasses a wide spectrum of neurobehavioral and neurological disturbances. Recent studies showed that the pathophysiology of neurocognitive dysfunction in CRF is related to plasma levels of uremic solutes. Successful renal transplantation improves renal, metabolic, and endocrine functions and the quality of life. The aim of our study was to determine the state of neurocognitive function in pediatric renal transplant recipients. We prospectively performed a neurological examination and neuropsychological test battery (Bender-Gestalt Test, Cancellation Test, and Visual and Auditory Number Assay Test) in 20 pediatric renal transplant recipients between 6 and 16 years of age. Twenty healthy children and 20 children with CRF were included in the study as the control groups. Mean age of the renal transplant recipients was 13.50 ± 3.40 years old. Mean evaluation time after transplantation was 2.0 ± 0.5 years. Bender-Gestalt Test result was abnormal in 40% of patients. The results of the Cancellation Test and the Visual and Auditory Number Assay Test showed significant decline in pediatric renal transplant patients when compared with the control. We found that neurocognitive dysfunction was frequent in pediatric renal transplantation patients. Awareness of this potential problem may be helpful for early recognition and treatment. Our findings suggest that periodic neurocognitive assessments may be indicated in transplant recipients.
Assuntos
Transtornos Cognitivos/etiologia , Cognição , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Adolescente , Comportamento do Adolescente , Fatores Etários , Teste de Bender-Gestalt , Estudos de Casos e Controles , Criança , Comportamento Infantil , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/psicologia , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/psicologia , Valor Preditivo dos Testes , Estudos Prospectivos , Resultado do TratamentoRESUMO
We have studied the effect of platelet-activating factor (PAF) on the physico-chemical organization of human lymphocyte plasma membranes by measuring the steady-state fluorescence anisotropy and the fluorescence decay of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) incorporated in lymphocyte plasma membranes. PAF induced a time-limited and significant increase of the lipid order in the exterior part of the membrane and a decrease in membrane heterogeneity. These changes were blocked in the presence of PAF antagonist L-659,989. The results indicate that the observed changes in the physico-chemical properties of the lymphocyte plasma membranes may be attributed to a PAF-receptor interaction.
Assuntos
Linfócitos/química , Fator de Ativação de Plaquetas/farmacologia , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Fenômenos Químicos , Físico-Química , Difenilexatrieno/análogos & derivados , Polarização de Fluorescência , Corantes Fluorescentes , Furanos/farmacologia , Meia-Vida , Humanos , Linfócitos/efeitos dos fármacos , Fator de Ativação de Plaquetas/antagonistas & inibidoresRESUMO
Plasma membrane fluidity and heterogeneity of polymorphonuclear leukocytes (PMN) were investigated in seven children with primary ciliary dyskinesia (PCD) and 17 healthy controls. Membrane fluidity and heterogeneity were studied by measuring the steady state fluorescence anisotropy and fluorescence decay of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) incorporated into PMN plasma membrane. Our results show an increase in membrane fluidity at the surface level of PMN from patients with PCD. Distribution analysis of TMA-DPH lifetime values indicate an increase in membrane heterogeneity in subjects with PCD. The observed changes in the physicochemical properties of the membrane could lead to alterations in the function of PMN from children with PCD.
Assuntos
Transtornos da Motilidade Ciliar/sangue , Fluidez de Membrana , Neutrófilos/fisiologia , Quimiotaxia de Leucócito/fisiologia , Criança , Pré-Escolar , Transtornos da Motilidade Ciliar/imunologia , Difenilexatrieno/análogos & derivados , Feminino , Polarização de Fluorescência , Corantes Fluorescentes , Humanos , Lactente , Masculino , Neutrófilos/imunologiaRESUMO
The effect of PAF on the plasma membrane polarity of polymorphonuclear leukocytes (PMNs) was investigated by measuring the steady-state fluorescence emission spectra of 2-dimethylamino(6-1auroyl) naphthalene (Laurdan), which is known to be incorporated at the hydrophobic-hydrophilic interface of the bilayer, displaying spectral sensitivity to the polarity of its surrounding. Laurdan shows a marked steady-state emission blue-shift in non-polar solvents, with respect to polar solvents. Our results demonstrate that PAF (10(-7) M) induces a blue shift of the fluorescence emission spectra of Laurdan. These changes are blocked in the presence of the PAF antagonist, L-659,989. Our data indicate that the interaction between PAF and PMNs is accompanied by a decrease in polarity in the hydrophobic-hydrophilic interface of the plasma membrane.
RESUMO
Changes in membrane polarity of human platelets during the interaction with PAF were investigated by measuring the steady-state fluorescence emission spectra of 2-dimethylamino(6-lauroyl)naphthalene (Laurdan), which is known to be incorporated at the hydrophobic-hydrophilic interface of the bilayer, displaying spectral sensitivity to the polarity of its surroundings. Laurdan shows a marked steady-state emission red-shift in polar solvents, with respect to non-polar solvents. Our results demonstrate that platelet activation factor (PAF) (10(-7) M) induces a red-shift of the fluorescence emission spectra of Laurdan. These changes were not observed in the presence of the PAF antagonist, L-659,989. These data suggest that the interaction of PAF with its specific receptor and the signalling pathways involved in platelet activation are accompanied by an increase in polarity at the hydrophobic-hydrophilic interface of human platelet membranes.
RESUMO
The interaction between PAF and human platelet membranes was investigated by measuring the steadystate fluorescence anisotropy and fluorescence decay of 1 (4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) incorporated in platelet plasma membranes. PAF induced a time-limited and significant increase of the lipid order in the exterior part of the membrane and a decrease in membrane heterogeneity. These changes were blocked in the presence of the PAF antagonists, L-659,989 and 1-O-hexadecyl-2-acetyl-sn-glycero-3-phospho(N,N,N-trimethyl)hexanolamine.H(2)O. These results indicate that the observed changes in the physico-chemical properties of the membrane are attributed to the PAF-receptor interaction and signal transduction.
RESUMO
Plasma membrane fluidity of polymorphonuclear leukocytes was investigated in 28 patients with insulin dependent diabetes mellitus and 30 healthy controls. Membrane fluidity was measured by steady-state fluorescence anisotropy of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) incorporated into the plasma membrane. The fluorescence anisotropy values in resting (unstimulated) polymorphonuclear leukocytes from diabetic subjects were significantly higher than those of controls (0.318 +/- 0.003 vs 0.287 +/- 0.003, P less than 0.001). The addition of the respiratory burst stimulus phorbol myristate acetate induced a stable increase in fluorescence anisotropy values in both groups. Fluorescence anisotropy values of stimulated polymorphonuclear leukocytes from the diabetic and control groups were not significantly different (P greater than 0.05). These data demonstrate a decrease in plasma membrane fluidity of resting polymorphonuclear leukocytes obtained from diabetic subjects. This finding could be in part explained by an increase in their basal respiratory burst activity.