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1.
Haemophilia ; 21(6): e456-64, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26179213

RESUMO

INTRODUCTION: Distress may affect a patient's ability to cope with and manage disease. AIM: To report distress prevalence in adult patients with bleeding disorders and determine whether specific clinical and health characteristics, including disease severity and employment status, are associated with distress. METHODS: Patients who visited a Haemophilia Treatment Centre (HTC) between January 1st, 2012 through February 28th, 2014 and who completed a distress screen, pain screen and questionnaire were evaluated cross sectionally. Distress was measured by the National Comprehensive Cancer Network Distress Management Tool, which allowed patients to rate recent distress on a 0-10 point scale. A rating of five or more was categorized as high distress. Pain was measured by the Brief Pain Inventory Short Form, which asked patients to rate pain types on 0-10 point scales. Patients reported employment and other demographic and behavioural information on the questionnaire. Primary diagnosis, age, HIV and HCV status were abstracted from medical records. Adjusted logistic regression was used to identify distress associations. RESULTS: High distress prevalence among 152 patients with bleeding disorders was 31.6%. Unemployment, disability, greater depressive symptoms and higher pain were associated with high distress in multivariable models. Bleeding disorder diagnosis, race/ethnicity, HIV/HCV status and on-demand treatment regimen were not associated with high distress. CONCLUSION: Distress among patients with congenital bleeding disorders followed at a comprehensive HTC was high and similar to that reported among patients with cancer. Future research should determine whether distress impacts clinical outcomes in patients with bleeding disorders as demonstrated in other chronic disorders.


Assuntos
Depressão/etiologia , Hemorragia/psicologia , Adulto , Estudos de Coortes , Estudos Transversais , Depressão/epidemiologia , Feminino , Humanos , Masculino , Qualidade de Vida
2.
Adv Exp Med Biol ; 860: 221-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26303484

RESUMO

The carotid bodies (CBs) are peripheral chemoreceptors that respond to hypoxia increasing minute ventilation and activating the sympathetic nervous system. Besides its role in ventilation we recently described that CB regulate peripheral insulin sensitivity. Knowing that the CB is functionally blocked by hyperoxia and that hyperbaric oxygen therapy (HBOT) improves fasting blood glucose in diabetes patients, we have investigated the effect of HBOT on glucose tolerance in type 2 diabetes patients. Volunteers with indication for HBOT were recruited at the Subaquatic and Hyperbaric Medicine Center of Portuguese Navy and divided into two groups: type 2 diabetes patients and controls. Groups were submitted to 20 sessions of HBOT. OGTT were done before the first and after the last HBOT session. Sixteen diabetic patients and 16 control individual were included. Fasting glycemia was143.5 ± 12.62 mg/dl in diabetic patients and 92.06 ± 2.99 mg/dl in controls. In diabetic patients glycemia post-OGTT was 280.25 ± 22.29 mg/dl before the first HBOT session. After 20 sessions, fasting and 2 h post-OGTT glycemia decreased significantly. In control group HBOT did not modify fasting glycemia and post-OGTT glycemia. Our results showed that HBOT ameliorates glucose tolerance in diabetic patients and suggest that HBOT could be used as a therapeutic intervention for type 2 diabetes.


Assuntos
Glicemia/metabolismo , Corpo Carotídeo/fisiologia , Diabetes Mellitus Tipo 2/terapia , Homeostase , Oxigenoterapia Hiperbárica , Idoso , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino , Pessoa de Meia-Idade
3.
Adv Exp Med Biol ; 860: 379-85, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26303503

RESUMO

Leptin is a hormone produced mostly in adipose tissue and playing a key role in the control of feeding and energy expenditure aiming to maintain a balance between food intake and metabolic activity. In recent years, it has been described that leptin might also contributes to control ventilation as the administration of the hormone reverses the hypoxia and hypercapnia commonly encountered in ob/ob mice which show absence of the functional hormone. In addition, it has been shown that the carotid body (CB) of the rat expresses leptin as well as the functional leptin-B receptor. Therefore, the possibility exists that the ventilatory effects of leptin are mediated by the CB chemoreceptors. In the experiments described below we confirm the stimulatory effect of leptin on ventilation, finding additionally that the CB does not mediate the instant to instant control of ventilation.


Assuntos
Corpo Carotídeo/fisiologia , Leptina/farmacologia , Respiração/efeitos dos fármacos , Animais , Glicemia/análise , Catecolaminas/metabolismo , Hipóxia/fisiopatologia , Leptina/sangue , Ratos , Ratos Wistar
4.
Dement Geriatr Cogn Disord ; 37(1-2): 1-18, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24107621

RESUMO

BACKGROUND/AIMS: Neuroinflammation plays a crucial role in the pathogenesis of Alzheimer's disease (AD). Its relationship with underlying ß amyloid deposition remains unclear. In vivo visualization of microglial activation has become possible with the development of molecular imaging ligands when used with positron emission tomography (PET). The translocator protein (TSPO) is upregulated during neuroinflammation. Consequently, targeting TSPO with radiolabeled ligands for PET is an attractive biomarker for neuroinflammation. METHODS: A review of the research literature on PET imaging which studied in vivo neuroinflammation in AD subjects and its relationship with amyloid load was performed, including papers published between 2001 and 2012. RESULTS: Six studies were included using either [(11)C]PK-11195 or another non-TSPO radioligand that binds to the monoaminooxidase B. All the studies evaluated amyloid load with [(11)C]PIB. Microglial activation and astrocytosis are potentially early phenomena in AD. However, the individual levels of amyloid deposition and microglial activation were not correlated. CONCLUSION: Noninvasive in vivo molecular imaging to visualize neuroinflammation in AD may contribute to our understanding of the kinetics of neuroinflammation and its relationship to the hallmarks of the disease. Both are important for the development of future therapeutic modalities and for quantifying the efficacy of future disease-modifying treatments.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Encéfalo/patologia , Inflamação/patologia , Imagem Molecular/métodos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Compostos de Anilina , Benzotiazóis , Humanos , Isoquinolinas , Translocases Mitocondriais de ADP e ATP/metabolismo , Monoaminoxidase/metabolismo , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tiazóis , Proteínas tau/metabolismo
5.
Eur J Nucl Med Mol Imaging ; 39(4): 621-31, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22252372

RESUMO

PURPOSE: Positron emission tomography (PET) imaging of brain amyloid load has been suggested as a core biomarker for Alzheimer's disease (AD). The aim of this study was to test the feasibility of using PET imaging with (18)F-AV-45 (florbetapir) in a routine clinical environment to differentiate between patients with mild to moderate AD and mild cognitive impairment (MCI) from normal healthy controls (HC). METHODS: In this study, 46 subjects (20 men and 26 women, mean age of 69.0 ± 7.6 years), including 13 with AD, 12 with MCI and 21 HC subjects, were enrolled from three academic memory clinics. PET images were acquired over a 10-min period 50 min after injection of florbetapir (mean ± SD of radioactivity injected, 259 ± 57 MBq). PET images were assessed visually by two individuals blinded to any clinical information and quantitatively via the standard uptake value ratio (SUVr) in the specific regions of interest, which were defined in relation to the cerebellum as the reference region. RESULTS: The mean values of SUVr were higher in AD patients (median 1.20, Q1-Q3 1.16-1.30) than in HC subjects (median 1.05, Q1-Q3 1.04-1.08; p = 0.0001) in the overall cortex and all cortical regions (precuneus, anterior and posterior cingulate, and frontal median, temporal, parietal and occipital cortex). The MCI subjects also showed a higher uptake of florbetapir in the posterior cingulate cortex (median 1.06, Q1-Q3 0.97-1.28) compared with HC subjects (median 0.95, Q1-Q3 0.82-1.02; p = 0.03). Qualitative visual assessment of the PET scans showed a sensitivity of 84.6% (95% CI 0.55-0.98) and a specificity of 38.1% (95% CI 0.18-0.62) for discriminating AD patients from HC subjects; however, the quantitative assessment of the global cortex SUVr showed a sensitivity of 92.3% and specificity of 90.5% with a cut-off value of 1.122 (area under the curve 0.894). CONCLUSION: These preliminary results suggest that PET with florbetapir is a safe and suitable biomarker for AD that can be used routinely in a clinical environment. However, the low specificity of the visual PET scan assessment could be improved by the use of specific training and automatic or semiautomatic quantification tools.


Assuntos
Amiloide/metabolismo , Compostos de Anilina , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Etilenoglicóis , Tomografia por Emissão de Pósitrons/métodos , Idoso , Doença de Alzheimer/diagnóstico por imagem , Compostos de Anilina/efeitos adversos , Disfunção Cognitiva/diagnóstico por imagem , Etilenoglicóis/efeitos adversos , Feminino , Seguimentos , Humanos , Masculino , Tomografia por Emissão de Pósitrons/efeitos adversos
6.
J Med Genet ; 47(11): 752-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20685672

RESUMO

BACKGROUND: Congenital hyperinsulinism (CHI) is characterised by an over secretion of insulin by the pancreatic ß-cells. This condition is mostly caused by mutations in ABCC8 or KCNJ11 genes encoding the SUR1 and KIR6.2 subunits of the ATP-sensitive potassium (K(ATP)) channel. CHI patients are classified according to their responsiveness to diazoxide and to their histopathological diagnosis (either focal, diffuse or atypical forms). Here, we raise the benefits/limits of the genetic diagnosis in the clinical management of CHI patients. METHODS: ABCC8/KCNJ11 mutational spectrum was established in 109 diazoxide-unresponsive CHI patients for whom an appropriate clinical management is essential to prevent brain damage. Relationships between genotype and radiopathological diagnosis were analysed. RESULTS: ABCC8 or KCNJ11 defects were found in 82% of the CHI cases. All patients with a focal form were associated with a single K(ATP) channel molecular event. In contrast, patients with diffuse forms were genetically more heterogeneous: 47% were associated with recessively inherited mutations, 34% carried a single heterozygous mutation and 19% had no mutation. There appeared to be a predominance of paternally inherited mutations in patients diagnosed with a diffuse form and carrying a sole K(ATP) channel mutation. CONCLUSIONS: The identification of recessively inherited mutations related to severe and diffuse forms of CHI provides an informative genetic diagnosis and allows prenatal diagnosis. In contrast, in patients carrying a single K(ATP) channel mutation, genetic analysis should be confronted with the PET imaging to categorise patients as focal or diffuse forms in order to get the appropriate therapeutic management.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Hiperinsulinismo Congênito/genética , Mutação , Canais de Potássio Corretores do Fluxo de Internalização/genética , Receptores de Droga/genética , Hiperinsulinismo Congênito/diagnóstico , Hiperinsulinismo Congênito/tratamento farmacológico , Análise Mutacional de DNA , Diazóxido/uso terapêutico , Resistência a Medicamentos , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Receptores de Sulfonilureias , Vasodilatadores/uso terapêutico
8.
Ann Readapt Med Phys ; 51(2): 59-73, 2008 Mar.
Artigo em Inglês, Francês | MEDLINE | ID: mdl-18207276

RESUMO

AIM: The aim of the present study was to analyse the effects of training performed on a rotating, motorised platform (the Huber/SpineForce device from LPG Systems, Valence, France) intended to improve, postural control and muscle function. SUBJECTS: Twelve healthy adults (divided into a sedentary group and an active group) took part in a two-month training programme (involving three sessions a week) on the SpineForce whole body rehabilitation device. METHOD: Instrumental assessment of postural control (on a Satel platform) and muscle function (on a Cybex Norm) was performed before and after training. Postural control in various conditions was measured using a position parameter (the mean anteroposterior position of the centre of foot pressure [CoP]) and two stability parameters (maximum CoP displacement and CoP sway area). Assessment of the muscle function was performed during knee and spine extension and featured maximum voluntary isometric contraction (MVIC), root mean square (RMS) and neuromuscular efficiency (MVIC/RMS) measurements. RESULTS: For static postural control, we observed a more forward CoP position in the maximum backward inclination condition (p<0.01) and a decrease in maximum CoP displacement in the "eyes closed on foam" and "maximum anterior inclination" conditions. In this latter condition, a lower CoP sway area was also noted (p<0.01). In terms of muscle function, a greater MVIC for knee extension was observed in the sedentary group only (p<0.05). These changes were not correlated with each another (p<0.05). However, the value of the pretraining maximum CoP displacement predicted its final value (p<0.05). CONCLUSION: Our results suggest that static postural control responds to training on a Huber((R))/SpineForce rehabilitation device. It seems probable that a population with a low initial level of physical activity would benefit most from training on this type of device. This training could notably be applied to elderly or disabled people and especially those with sensorimotor disabilities.


Assuntos
Pessoas com Deficiência/reabilitação , Terapia por Exercício/instrumentação , Força Muscular , Equilíbrio Postural , Reabilitação/instrumentação , Adulto , Eletromiografia , Feminino , Humanos , Contração Isométrica , Cinestesia , Masculino , Pessoa de Meia-Idade , Ocupações , Estatísticas não Paramétricas , Inquéritos e Questionários , Fatores de Tempo
9.
Hum Pathol ; 38(3): 387-99, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17303499

RESUMO

Neonatal hyperinsulinism is a life-threatening disease that, when treated by total pancreatectomy, leads to diabetes and pancreatic insufficiency. A more conservative approach is now possible since the separation of the disease into a nonrecurring focal form, which is cured by partial surgery, and a diffuse form, which necessitates total pancreas removal only in cases of medical treatment failure. The pathogenesis of the disease is now divided into K-channel disease (hyperinsulinemic hypoglycemia, familial [HHF] 1 and 2), which can mandate surgery, and other metabolic causes, HHF 3 to 6, which are treated medically in most patients. The diffuse form is inherited as a recessive gene on chromosome 11, whereas most cases of the focal form are caused by a sulfonylurea receptor 1 defect inherited from the father, which is associated with a loss of heterozygosity on the corresponding part of the mother's chromosome 11. The rare bifocal forms result from a maternal loss of heterozygosity specific to each focus. Paternal disomy of chromosome 11 is a rare cause of a condition similar to Beckwith-Wiedemann syndrome. A preoperative PET scan with fluorodihydroxyphenylalanine and perioperative frozen-section confirmation are the types of studies done before surgery when needed. Adult variants of the disease are less well defined at the present time.


Assuntos
Hiperinsulinismo Congênito , Transportadores de Cassetes de Ligação de ATP/genética , Biópsia , Hiperinsulinismo Congênito/genética , Hiperinsulinismo Congênito/patologia , Hiperinsulinismo Congênito/fisiopatologia , Hiperinsulinismo Congênito/terapia , Secções Congeladas , Humanos , Lactente , Recém-Nascido , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/patologia , Síndrome de Munchausen/diagnóstico , Nesidioblastose/patologia , Pâncreas/embriologia , Canais de Potássio/genética , Canais de Potássio Corretores do Fluxo de Internalização/genética , Receptores de Droga/genética , Receptores de Sulfonilureias
10.
Braz J Biol ; 66(2A): 421-30, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16862295

RESUMO

Spatial and temporal density and biomass distribution of the planktonic copepods Pseudodiaptomus richardi and P. acutus along a salinity gradient were investigated in the Caeté River Estuary (North-Brazil) in June and December, 1998 (dry season) and in February and May, 1999 (rainy season). Copepod biomass was estimated using regression parameters based on the relation of dry weight and body length (prosome) of adult organisms. The Caeté River Estuary was characterized by high spatial and temporal variations in salinity (0.8-37.2). Exponential length-weight relationships were observed for both Pseudodiaptomus species. Density and biomass values oscillated between 0.28-46.18 ind. m-3 and 0.0022-0.3507 mg DW. m-3 for P. richardi; and between 0.01-17.02 ind. m-3 and 0.0005-0.7181 mg DW. m-3 for P. acutus. The results showed that the contribution of P. richardi for the secondary production in the Caeté River Estuary is more important in the limnetic zone than in other zones where euhaline-polyhaline regimes were predominant. However, it was not possible to observe a clear pattern of spatial and temporal distribution for P. acutus.


Assuntos
Biomassa , Copépodes/classificação , Animais , Brasil , Densidade Demográfica , Dinâmica Populacional , Rios , Estações do Ano
11.
Respir Physiol Neurobiol ; 228: 30-8, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26993367

RESUMO

Chronic intermittent hypoxia (CIH) is a feature of obstructive sleep apnea (OSA). Whereas clinical studies have demonstrated the association between OSA and insulin resistance, the molecular mechanisms behind it are still unknown. Herein we investigated the effect of mild CIH on insulin sensitivity and we evaluated the changes in insulin and HIF signaling pathways that occur in CIH-induced insulin resistance. We showed that mild CIH obtained by 5/6 hypoxic (5%O2) cycles/h, 10.5h/day during 28 and 35 days increased arterial blood pressure. Insulin resistance and insulinemia increased with CIH duration, being significantly different after 35 days of CIH. Thirty-five days of CIH decreased insulin receptor expression and phosphorylation in skeletal muscle and adipose tissue, but not in the liver. Conversely, Glut2 expression increased in the liver of CIH-animals. Thirty-five days of CIH up-regulated HIF-1α in the liver and down-regulated HIF-1α and HIF-2α in skeletal muscle. We concluded that the effect of CIH on insulin sensitivity and signaling is time-dependent and is associated with changes in HIF signaling in insulin-sensitive tissues.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/metabolismo , Resistência à Insulina/fisiologia , Tecido Adiposo/metabolismo , Animais , Pressão Arterial/fisiologia , Peso Corporal , Modelos Animais de Doenças , Transportador de Glucose Tipo 2/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Insulina/sangue , Lipídeos/sangue , Fígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Fosforilação , Ratos Wistar , Receptor de Insulina/metabolismo , Apneia Obstrutiva do Sono/metabolismo
12.
Biochim Biophys Acta ; 1200(2): 139-47, 1994 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-8031833

RESUMO

When different strains of Saccharomyces cerevisiae grown at 23 degrees C were transferred to 36 degrees C, trehalose and glycogen were accumulated. Glycogen accumulation was less extensive and its synthesis started at least 15 min after initiation of trehalose synthesis. The steady-state intracellular concentration of trehalose increased simultaneously with the activities of the enzymes trehalose-6P synthase, UDPG-pyrophosphorylase, phosphoglucomutase and trehalase. A small but significant change was observed in hexokinase activity. Our results directly implicate isoform PII of hexokinase and the minor isoform of phosphoglucomutase in the pathway of trehalose formation during heat-shock. We also showed that the major isoform of phosphoglucomutase increased in activity but was not essential for trehalose accumulation. Studies with the glucose uptake system indicated that trehalose accumulation could be primarily determined by intracellular availability of substrates due to the increase in the rate of glucose uptake. The increased uptake appears to have two components: a kinetic effect of temperature upon glucose transporters and an increase in the numbers of molecules of the transporters, probably mediated by synthesis de novo.


Assuntos
Saccharomyces cerevisiae/metabolismo , Trealose/metabolismo , Glucosiltransferases/metabolismo , Hexoquinase/metabolismo , Temperatura Alta , Modelos Químicos , Fosfoglucomutase/metabolismo , Trealase/metabolismo , UTP-Glucose-1-Fosfato Uridililtransferase/metabolismo
13.
Arch Pediatr ; 12(11): 1628-35, 2005 Nov.
Artigo em Francês | MEDLINE | ID: mdl-16198094

RESUMO

Congenital hyperinsulinism (HI) is the most important cause of hypoglycaemia in early infancy. The inappropriate oversecretion of insulin is responsible for profound hypoglycaemias requiring aggressive treatment to prevent severe and irreversible brain damage. Several classifications of HI can be attempted, based on: 1) the onset of hypoglycemia in the neonatal period or later in infancy; 2) the histological lesion: focal or diffuse; 3) the genetic transmission: sporadic, recessive, or less frequently dominant. The most common underlying mechanism of HI is dysfunction of the pancreatic ATP-sensitive potassium channel (K(+)(ATP)). The 2 subunits of the K(+)(ATP) channel are encoded by either the sulfonylurea receptor gene (SUR1 or ABCC8) or the inward-rectifying potassium channel gene (KIR6.2. or KCNJ11), both located in the 11p15.1 region. Focal CHI has been shown to result from a paternally inherited mutation on the SUR1 or KIR6.2 gene and loss of the maternal 11p15 allele restricted to the pancreatic lesion. Diffuse HI, frequently due to mutations of the SUR1 or KIR6.2 genes of autosomal recessive inheritance is genetically heterogeneous. The distinction between the focal and the diffuse HI is very important, because the treatments are different. To distinguish between focal and diffuse HI, transhepatic catheterisation with pancreatic venous sampling was the reference technique, but will likely be replaced by [(18)F] Fluoro-L-Dopa PET scan, which is easier to perform. In absence of response to the medical treatment (diazoxide) a limited pancreatectomy permits to cure focal HI, while a diffuse HI requires a subtotal pancreatectomy with high risk of subsequent diabetes mellitus.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Hiperinsulinismo Congênito/complicações , Hiperinsulinismo Congênito/genética , Canais de Potássio Corretores do Fluxo de Internalização/genética , Canais de Potássio/genética , Receptores de Droga/genética , Transportadores de Cassetes de Ligação de ATP/fisiologia , Criança , Pré-Escolar , Hiperinsulinismo Congênito/patologia , Hiperinsulinismo Congênito/cirurgia , Diazóxido/uso terapêutico , Feminino , Humanos , Lactente , Masculino , Mutação , Pancreatectomia , Canais de Potássio/fisiologia , Canais de Potássio Corretores do Fluxo de Internalização/fisiologia , Receptores de Droga/fisiologia , Receptores de Sulfonilureias , Vasodilatadores/uso terapêutico
14.
J Cereb Blood Flow Metab ; 18(9): 951-9, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9740098

RESUMO

Three-dimensional (3D) positron emission tomography (PET) is attractive for [18F]fluoro-DOPA studies, since the sensitivity improvement is maximal for radioactive sources located in central planes, which is usually the case for the human striata. However, the image quantitation in that mode must be assessed because of the nearly threefold increase in scattered coincidences. We report the results of [18F]fluoro-DOPA studies performed on six normal volunteers. Each one was scanned in the 3D and two-dimensional (2D) modes on the same tomograph. The quantitation in the 3D and 2D modes was compared for a Patlak graphical analysis with the occipital counts as the input function (Ki) and a striatooccipital ratio analysis. We find that, in 3D PET, a scatter correction is required to preserve the same quantitation as in 2D PET. When the 3D data sets are corrected for scatter, the quantitation of the [18F]fluoro-DOPA uptake, using the Patlak analysis, is similar in the 2D and 3D acquisition modes. Conversely, analysis of the striatooccipital ratio leads to higher values in 3D PET because of a better in-plane resolution. Finally, using the 3D mode, the dose injected to the subjects can be reduced by a factor greater than 1.5 without any loss in accuracy compared to the 2D mode.


Assuntos
Corpo Estriado/metabolismo , Di-Hidroxifenilalanina/análogos & derivados , Tomografia Computadorizada de Emissão/métodos , Adulto , Mapeamento Encefálico , Corpo Estriado/diagnóstico por imagem , Di-Hidroxifenilalanina/metabolismo , Humanos , Modelos Lineares , Masculino , Lobo Occipital/metabolismo , Valores de Referência , Reprodutibilidade dos Testes
15.
Peptides ; 9(5): 945-55, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3244563

RESUMO

Two endopeptidases displaying similar specificities towards peptide hormone substrates but differing in molecular size have been identified in rabbit heart and isolated by a combination of ion-exchange chromatography, gel filtration and preparative gel electrophoresis. These two enzymes share several properties with the previously described rabbit brain endooligopeptidase A. They were shown to produce, by a single peptide bond cleavage, [Met5] enkephalin and [Leu5]enkephalin from small enkephalin containing peptides. They also hydrolyze the Phe5-Ser5 bond of bradykinin and the Arg8-Arg9 bond of neurotensin. Characteristically, the activity of both low and high Mr enzymes is restricted to oligopeptides. Both forms of heart endooligopeptidase A are inhibited by antibodies raised against the brain enzyme. When electrophoresed in SDS-polyacrylamide gel under denaturing conditions, the low Mr heart enzyme shows a major band of Mr = 73,000, comparable in size to the brain enzyme. The SDS-PAGE of the high and low Mr enzymes analyzed by immunoblotting with an antibody raised against low Mr brain endooligopeptidase A, showed a major antigen band corresponding to Mr = 72,000. In addition, immunoblotting has also demonstrated that a monoclonal antibody antitubulin reacts with a polypeptide corresponding to Mr = 50,000 present in the purified high Mr endooligopeptidase A. Both enzymes are activated by dithiothreitol and inhibited by thiol reagents, but are not affected by leupeptin, DFP or EDTA, thus indicating that they should be classified as nonlysosomal cysteinyl-endooligopeptidase A.


Assuntos
Cisteína Endopeptidases/metabolismo , Encefalinas/biossíntese , Metaloendopeptidases , Miocárdio/enzimologia , Neuropeptídeos/metabolismo , Sequência de Aminoácidos , Animais , Cromatografia DEAE-Celulose , Cromatografia em Gel , Cisteína Endopeptidases/isolamento & purificação , Eletroforese Descontínua , Eletroforese em Gel de Poliacrilamida , Indicadores e Reagentes , Peso Molecular , Coelhos , Especificidade por Substrato
16.
Neuropeptides ; 26(4): 281-7, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7913210

RESUMO

A series of biologically active peptides and related compounds (opioid peptides, neurotensin, and bradykinin) were used as substrates or competitive inhibitors to study the structural requirements for peptide interaction with endopeptidase 22.19. The kinetics of hydrolysis of these peptides indicated that, in contrast to other proteases, the substrate specificity of endopeptidase 22.19 is not determined by the amino acids flanking the sensitive bonds of the substrates. The competition between bioactive peptide analogues and the quenched fluorescence substrate of endopeptidase 22.19 indicated that their length and their flexibility may be the dominant factors to explain their binding specificities. These peculiar features of endopeptidase 22.19 may be of importance to understand the physiological processes of conversion and inactivation of biologically active peptides.


Assuntos
Metaloendopeptidases/metabolismo , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Sequência de Aminoácidos , Animais , Bradicinina/análogos & derivados , Bradicinina/química , Bradicinina/metabolismo , Encéfalo/enzimologia , Dinorfinas/análogos & derivados , Dinorfinas/química , Dinorfinas/metabolismo , Metaloendopeptidases/antagonistas & inibidores , Dados de Sequência Molecular , Neuropeptídeos/farmacologia , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Coelhos , Relação Estrutura-Atividade , Especificidade por Substrato , beta-Lipotropina/análogos & derivados , beta-Lipotropina/química , beta-Lipotropina/metabolismo
17.
Thromb Res ; 79(2): 153-61, 1995 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-7676402

RESUMO

HMEC-1 is a SV-40T transfected human microvascular endothelial cell line that constitutively expresses RNA transcripts for plasminogen activator inhibitor 1 (PAI-1), tissue-type plasminogen activator (t-PA), protein S (PS), von Willebrand factor (vWF), and thrombomodulin. Tissue factor (TF) can be induced in response to stimulation with tumor necrosis factor alpha (TNF-alpha), interleukin-1 alpha (IL-1alpha) and phorbol 12-myristate 13-acetate (PMA). Proteins corresponding to PAI-1, t-PA, protein S and vWF genes were constitutively released in the culture supernatant. This cell line is a model that will be useful to investigate coagulation/fibrinolytic properties of microvascular endothelium.


Assuntos
Hemostasia , Proteína Quinase C/efeitos dos fármacos , Vírus 40 dos Símios/genética , Transcrição Gênica/efeitos dos fármacos , Transfecção/genética , Metabolismo Basal , Sequência de Bases , Linhagem Celular , Endotélio Vascular/citologia , Ativação Enzimática , Humanos , Modelos Cardiovasculares , Dados de Sequência Molecular , Acetato de Tetradecanoilforbol/farmacologia
18.
Thromb Res ; 81(5): 577-81, 1996 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-8907316

RESUMO

Several recent studies have reported that the factor V Arg506-->Gln mutation is present in 3-10% of adults of European descent. To determine if the prevalence is comparable among Blacks, we have initiated a case-control study in a large urban hospital in Atlanta which serves a substantial black population. We have evaluated 131 black subjects with confirmed venous or arterial thrombosis and 61 black subjects without a history of thrombosis. Only one case and one control were positive for the Arg506-->Gln mutation. We conclude that the mutation is more common among Whites than Blacks.


Assuntos
Arginina/genética , Fator V/genética , Glicina/genética , Mutação Puntual , Sequência de Bases , População Negra , Estudos de Casos e Controles , Humanos , Dados de Sequência Molecular , População Branca
19.
Nucl Med Biol ; 25(4): 317-22, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9639291

RESUMO

The tumoral uptake of fluorine-18-deoxyglucose (FDG) is based upon enhanced glycolysis. Following injection, FDG is phosphorylated and trapped intracellularly. An important mechanism to transport FDG into the transformed cell is based upon the action of glucose transporter proteins; furthermore, highly active hexokinase bound to tumor mitochondria helps to trap FDG into the cell. In addition, enhanced FDG uptake may be due to relative hypoxia in tumor masses, which activates the anaerobic glycolytic pathway. In spite of these processes, FDG uptake is relatively aspecific since all living cells need glucose. Clinical use is therefore recommended in carefully selected patients.


Assuntos
Fluordesoxiglucose F18/farmacocinética , Glucose/metabolismo , Neoplasias/metabolismo , Compostos Radiofarmacêuticos/farmacocinética , Glicólise , Humanos , Mutagênese/genética , Neoplasias/diagnóstico por imagem , Neoplasias/genética , Cintilografia
20.
Nucl Med Biol ; 26(1): 79-83, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10096505

RESUMO

We report the synthesis, characterization, and biodistribution of 99mTc-complexes with the bidentate-N,N chelate biguanide (Big) and the N1-substituted ligands dimethyl (DMBig), phenyl (PBig), and phenethyl (PEBig). Dynamic gamma-camera studies with 99mTc-Big and 99mTc-DMSA in rabbits indicated distinct renal and urinary excretion profiles. 99mTc-Big was cleared more quickly than 99mTc-DMSA, and for the same acquisition times, the contrast in whole-body images favored 99mTc-Big. Also, the estimated radiation absorbed doses by kidneys and blood for 99mTc-DMSA were significantly higher than for 99mTc-Big. These preliminary studies show that 99mTc-Big has favourable practical and dosimetric features for renal imaging as an alternative to 99mTc-DMSA.


Assuntos
Biguanidas/síntese química , Rim/diagnóstico por imagem , Compostos de Organotecnécio/síntese química , Animais , Biguanidas/farmacocinética , Feminino , Camundongos , Compostos de Organotecnécio/farmacocinética , Ligação Proteica , Coelhos , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Ratos Wistar , Ácido Dimercaptossuccínico Tecnécio Tc 99m/farmacocinética , Contagem Corporal Total
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