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1.
Recent Adv Food Nutr Agric ; 15(1): 2-12, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38258781

RESUMO

Millets, small-seeded grasses, are gaining interest for their nutrition and health benefits. This abstract provides a comprehensive overview of millets' pharmacological activities, highlighting their rich bioactive compounds. These compounds, including phenolic compounds, flavonoids, and dietary fibers, contribute to antioxidant effects, safeguarding against chronic diseases. Millets also possess anti-inflammatory properties, potentially alleviating conditions, like arthritis and asthma. They show anti-carcinogenic potential, possibly preventing various cancers' development through mechanisms, like apoptosis induction and inhibiting tumor growth. Moreover, millets offer hypolipidemic and hypoglycemic effects, beneficial for managing conditions, such as dyslipidemia and diabetes. Their high dietary fiber and resistant starch content regulate blood lipids and glucose, reducing the cardiovascular risk. Additionally, millets act as antimicrobials, inhibiting pathogens and serving as natural alternatives to synthetic antimicrobials. They exhibit immunomodulatory effects, enhancing immune function and response. Overall, millets' pharmacological properties, including antioxidant, antiinflammatory, anti-carcinogenic, hypolipidemic, hypoglycemic, antimicrobial, and immunomodulatory traits, position them as functional foods with varied health benefits. Further research can integrate millets into preventive and therapeutic approaches for diverse diseases.


Assuntos
Suplementos Nutricionais , Humanos , Alimento Funcional , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Fibras na Dieta/uso terapêutico , Hipoglicemiantes/uso terapêutico , Hipoglicemiantes/farmacologia
2.
Water Res ; 46(9): 2937-46, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22494493

RESUMO

The presence of micropollutants can be a concern for land application of biosolids. Of particular interest are nonylphenol diethoxylate (NP(2)EO), nonylphenol monoethoxylate (NP(1)EO), and nonylphenol (NP), collectively referred to as NPE, which accumulate in anaerobically digested biosolids and are subject to regulation based on the environmental risks associated with them. Because biosolids are a valuable nutrient resource, it is essential that we understand how various treatment processes impact the fate of NPE in biosolids. Thermal hydrolysis (TH) coupled with mesophilic anaerobic digestion (MAD) is an advanced digestion process that destroys pathogens in biosolids and increases methane yields and volatile solids destruction. We investigated the impact of thermal hydrolysis pretreatment on the subsequent biodegradation of NPE in digested biosolids. Biosolids were treated with TH, anaerobic digestion, and aerobic digestion in laboratory-scale reactors, and NPE were analyzed in the influent and effluent of the digesters. NP(2)EO and NP(1)EO have been observed to degrade to the more estrogenic NP under anaerobic conditions; therefore, changes in the ratio of NP:NPE were of interest. The increase in NP:NPE following MAD was 56%; the average increase of this ratio in four sets of TH-MAD samples, however, was only 24.6 ± 3.1%. In addition, TH experiments performed in pure water verified that, during TH, the high temperature and pressure alone did not directly destroy NPE; TH experiments with NP added to sludge also showed that NP was not destroyed by the high temperature and pressure of TH when in a more complex sludge matrix. The post-aerobic digestion phases removed NPE, regardless of whether TH pretreatment occurred. This research indicates that changes in biosolids processing can have impacts beyond just gas production and solids destruction.


Assuntos
Fenóis/química , Esgotos , Anaerobiose , Cromatografia Líquida de Alta Pressão , Estrogênios/química , Hidrólise , Espectrometria de Massas por Ionização por Electrospray , Poluentes da Água/química
3.
J Tissue Eng Regen Med ; 4(8): 600-10, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20222010

RESUMO

The mechanism for stem cell-mediated improvement following acute myocardial infarction has been actively debated. We support hypotheses that the stem cell effect is primarily paracrine factor-linked. We used a heparin-presenting injectable nanofibre network to bind and deliver paracrine factors derived from hypoxic conditioned stem cell media to mimic this stem cell paracrine effect. Our self-assembling peptide nanofibres presenting heparin were capable of binding paracrine factors from a medium phase. When these factor-loaded materials were injected into the heart following coronary artery ligation in a mouse ischaemia-reperfusion model of acute myocardial infarction, we found significant preservation of haemodynamic function. Through media manipulation, we were able to determine that crucial factors are primarily < 30 kDa and primarily heparin-binding. Using recombinant VEGF- and bFGF-loaded nanofibre networks, the effect observed with conditioned media was recapitulated. When evaluated in another disease model, a chronic rat ischaemic hind limb, our factor-loaded materials contributed to extensive limb revascularization. These experiments demonstrate the potency of the paracrine effect associated with stem cell therapies and the potential of a biomaterial to bind and deliver these factors, pointing to a potential therapy based on synthetic materials and recombinant factors as an acellular therapy.


Assuntos
Doenças Cardiovasculares/terapia , Heparina/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Nanofibras/química , Comunicação Parácrina/efeitos dos fármacos , Animais , Meios de Cultivo Condicionados/farmacologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Ventrículos do Coração/fisiopatologia , Membro Posterior/irrigação sanguínea , Membro Posterior/efeitos dos fármacos , Membro Posterior/patologia , Transplante de Células-Tronco Mesenquimais , Camundongos , Peso Molecular , Contração Miocárdica/efeitos dos fármacos , Infarto do Miocárdio/fisiopatologia , Peptídeos/química , Peptídeos/metabolismo , Ratos , Fator A de Crescimento do Endotélio Vascular/metabolismo
4.
Biochemistry ; 45(36): 10987-97, 2006 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-16953585

RESUMO

This paper uses phospholipase Cepsilon as a model to demonstrate that lipids can act as ligands to bind to specific motifs and regulate protein activity via allosteric effects. Phospholipids such as phosphatidic acid and free fatty acids such as arachidonate are potent activators of PLCepsilon, increasing the rate of PI hydrolysis by 8-fold and 50-fold, respectively. The mechanism appears to be a reduction of K(m), as the substrate dependence curve is shifted to the left and K(m) is reduced 10-fold. The regulation of PLCepsilon by lipids appears to be physiologic, as reconstitution or cotransfection of either cPLA(2) or PLD with PLCepsilon leads to activation of phosphodiesterase activity. Additionally, TSA-201 cells transfected with PLCepsilon and fed arachidonic acid complexed with BSA had increased (4-5-fold) hydrolysis of polyphosphoinositides. This study demonstrates the ability of lipids to act as potent and direct mediators of protein function and identifies cross talk between different classes of phospholipase (PLD and PLA(2) with PLC) mediated via lipid products.


Assuntos
Ácidos Graxos/metabolismo , Fosfolipase D/metabolismo , Fosfolipases A/metabolismo , Fosfolipases Tipo C/metabolismo , Animais , Ácido Araquidônico/metabolismo , Ácido Araquidônico/farmacologia , Cálcio/metabolismo , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Hidrólise , Ácidos Fosfatídicos/metabolismo , Ácidos Fosfatídicos/farmacologia , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfoinositídeo Fosfolipase C , Fosfolipase D/genética , Fosfolipases A/genética , Fosfolipases A2 , Fosfolipídeos/metabolismo , Diester Fosfórico Hidrolases/metabolismo , Mapeamento de Interação de Proteínas , Fosfolipases Tipo C/genética , Fosfolipases Tipo C/isolamento & purificação
5.
Biochem Biophys Res Commun ; 307(2): 327-31, 2003 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-12859959

RESUMO

Intracellular transglutaminases (protein-glutamine: amine gamma-glutamyltransferase, EC 2.3.2.13) are calcium-dependent thiol enzymes that catalyze the covalent cross-linking of proteins, including those in the erythrocyte membrane. Several studies suggest that the activation of some transglutaminases is positively regulated by the calcium-dependent cysteine protease, mu-calpain. Using mu-calpain null (Capn1(-/-)) mouse erythrocytes, we demonstrate that the activation of soluble as well as membrane-bound forms of transglutaminase (TG2) in mouse erythrocytes was independent of mu-calpain. Also, the absence of mu-calpain or any detectable cysteine protease did not affect the transglutaminase activity in the erythrocyte lysate. Our studies also identify physiological substrates of mu-calpain in the erythrocyte membrane and show that their cleavage has no discernible effect on the transglutaminase mediated cross-linking of membrane proteins. Taken together, these data suggest the existence of a calpain-independent mechanism for the activation of transglutaminase 2 by calcium ions in the mouse erythrocytes and presumably also in non-erythroid cells.


Assuntos
Calpaína/fisiologia , Eritrócitos/enzimologia , Proteínas de Ligação ao GTP/metabolismo , Transglutaminases/metabolismo , Animais , Cálcio , Calpaína/genética , Ativação Enzimática , Camundongos , Camundongos Knockout , Proteína 2 Glutamina gama-Glutamiltransferase
6.
Metabolism ; 51(6): 783-6, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12037736

RESUMO

We studied the effect of troglitazone on the plasma concentrations of homocysteine (tHcy), the erythrocyte and hepatic concentrations of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), and the hepatic activities of cystathionine-beta-synthase (C beta S) and methylenetetrahydrofolate reductase (MTHFR) in lean and fatty Zucker rats (a model of insulin resistance). Four groups of female Zucker rats were studied. Troglitazone (200 mg/kg) was administered by gavage daily for 3 weeks to lean and fatty Zucker rats. The other 2 groups served as controls. The blood parameters were determined at days 0, 10, and 21. The hepatic SAM and SAH concentrations and MTHFR and C beta S were measured in the 3-week liver samples. Plasma homocysteine fell significantly in all troglitazone-treated animals from a mean +/- SD of 7.6 +/- 1.5 micromol/L to 4.5 +/- 1.1 micromol/L (P <.02) but not in control animals (5.7 +/-1.8 micromol/L to 5.9 +/- 1.8 micromol/L). The decreases induced by troglitazone in homocysteine were seen in both the lean and the fatty Zucker rats. This was accompanied by significant rises in the hepatic concentrations of SAH and SAM + SAH. In addition, a significant decline in the hepatic SAM/SAH ratio was observed. The mean +/- SD hepatic C beta S (expressed as nmol of cystathionine formed at 37 degrees C) in the troglitazone-treated rats was 1,226 +/- 47 nmol/h/mg protein, which was significantly higher than that in the control group (964 +/- 64 nmol/h/mg protein; P =.03). We conclude that troglitazone lowers plasma homocysteine in insulin-resistant animals. The homocysteine-lowering effects of troglitazone may be mediated in part by a shift in the concentrations of tHcy and its related metabolites from the blood to the liver as well as by an upregulation of hepatic C beta S activity. These data support the hypothesis that insulin may regulate homocysteine metabolism through regulation of hepatic C beta S activity, although activity of other hepatic enzymes not studied here may also contribute to these observations.


Assuntos
Cromanos/farmacologia , Eritrócitos/metabolismo , Homocisteína/sangue , Fígado/metabolismo , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Tiazóis/farmacologia , Tiazolidinedionas , Animais , Cistationina beta-Sintase/metabolismo , Eritrócitos/efeitos dos fármacos , Feminino , Hipoglicemiantes/farmacologia , Insulina/sangue , Resistência à Insulina/fisiologia , Fígado/efeitos dos fármacos , Metilenotetra-Hidrofolato Redutase (NADPH2) , Obesidade/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Ratos , Ratos Zucker , Magreza/metabolismo , Troglitazona
7.
J Child Neurol ; 17(2): 134-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11958186

RESUMO

We report a 12-year-old child with episodes of migraine-like headaches with visual and motor auras a year after the surgical resection and radiation therapy for medulloblastoma The patient presented with an episode of headache, prolonged aphasia, right hemiparesis, status epilepticus, and salt wasting. There was no evidence of a structural lesion. The neurologic deficits resolved over a period of 6 weeks. Because of the progressive deterioration in neurologic deficits, the patient underwent an extensive battery of laboratory tests and multiple neuroimages, all of which were normal. The unusually prolonged neurologic deficit in this patient without demonstrable structural lesions and his eventual complete recovery were most likely caused by ischemia in the left hemisphere secondary to vasospasm. This presentation mimics migraine headache. Evidence suggesting that this represents a long-term complication of treatment of children with central nervous system neoplasia is presented.


Assuntos
Neoplasias Cerebelares/radioterapia , Irradiação Craniana/efeitos adversos , Meduloblastoma/radioterapia , Transtornos de Enxaqueca/etiologia , Complicações Pós-Operatórias/etiologia , Isquemia Encefálica/complicações , Neoplasias Cerebelares/cirurgia , Criança , Terapia Combinada , Eletroencefalografia , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Meduloblastoma/cirurgia , Radioterapia Adjuvante , Fatores de Risco , Vasoespasmo Intracraniano/complicações
8.
Proc Natl Acad Sci U S A ; 99(5): 2738-42, 2002 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-11867764

RESUMO

Transglutaminase 2 (TG2) is a distinctive member of the family of Ca2+-dependent enzymes recognized mostly by their abilities to catalyze the posttranslational crosslinking of proteins. TG2 uniquely binds and hydrolyzes GTP; binding GTP inhibits its crosslinking activity but allows it to function in signal transduction (hence the G(h) designation). The core domain of TG2 (residues 139-471, rat) comprises the papain-like catalytic triad and the GTP-binding domain (residues 159-173) and contains almost all of the conserved tryptophans of the protein. Examining point mutations at Trp positions 180, 241, 278, 332, and 337 showed that, upon binding 2'-(or 3')-O-(N-methylanthraniloyl)GTP (mantGTP), the Phe-332 mutant was the weakest (35% less than wild type) in resonance energy transfer from the protein (lambda(exc, max) = 290 nm) to the mant fluorophore (lambda(em) = 444 nm) and had a reduced affinity for mantGTP. Trp-332, situated near the catalytic center and the nucleotide-binding area of TG2, may be part of the allosteric relay machinery that transmits negative effector signals from nucleotide binding to the active center of TG2. A most important observation was that, whereas no enzyme activity could be detected when Trp-241 was replaced with Ala or Gln, partial preservation of catalytic activity was seen with substitutions by Tyr > Phe > His. The results indicate that Trp-241 is essential for catalysis, possibly by stabilizing the transition states by H-bonding, quadrupole-ion, or van der Waals interactions. This contrasts with the evolutionarily related papain family of cysteine proteases, which uses Gln-19 (papain) for stabilizing the transition state.


Assuntos
Proteínas de Ligação ao GTP/metabolismo , Transglutaminases/metabolismo , Triptofano/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Catálise , Sequência Conservada , Proteínas de Ligação ao GTP/química , Proteínas de Ligação ao GTP/genética , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteína 2 Glutamina gama-Glutamiltransferase , Estrutura Terciária de Proteína , Ratos , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos , Transglutaminases/química , Transglutaminases/genética , Triptofano/genética
9.
Lab Invest ; 69(2): 238-49, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8350599

RESUMO

BACKGROUND: We undertook this study in order to fully characterize the clinical and histopathology features of the dextran sulfate sodium (DSS) model of experimental murine colitis and to discover the earliest histopathologic changes that lead to colitis. EXPERIMENTAL DESIGN: Acute colitis was induced in Swiss-Webster mice by 7 days of oral DSS with animals sacrificed daily. Chronic colitis was induced by: (a) 7 days of oral DSS followed by 7 days of H2O (for 1, 2, and 3 cycles) and (b) 7 days of oral DSS followed by 14 and 21 days of H2O. In each experimental group, the entire colons were examined histologically and correlated with clinical symptoms. RESULTS: Acute clinical symptoms (diarrhea and/or grossly bloody stool) were associated with the presence of erosions and inflammation. More importantly, the earliest histologic changes which predated clinical colitis was loss of the basal one-third of the crypt (day 3), which progressed with time to loss of the entire crypt resulting in erosions on day 5. The earliest changes were very focal and not associated with inflammation. Inflammation was a secondary phenomena and only became significant after erosions appeared. Animals treated with only 7 days of DSS followed by 14 and 21 days of H2O developed a chronic colitis with the following histologic features: areas of activity (erosions and inflammation), inactivity, crypt distortion, florid epithelial proliferation and possible dysplasia. These changes were similar to animals given 3 cycles of DSS. The clinical disease activity index correlated significantly with pathologic changes in both the acute and chronic phases of the disease. CONCLUSIONS: The mechanism of DSS colitis is presently unknown. However, the finding of crypt loss without proceeding or accompanying inflammation suggests that the initial insult is at the level of the epithelial cell with inflammation being a secondary phenomena. This may be a good model to study how early mucosal changes lead to inflammation and the biology of the colonic enterocyte. Chronic colitis induced after only 7 days of DSS may serve as a useful model to study the effects of pharmacologic agents in human inflammatory disease and mechanisms of perpetuation of inflammation. Finally, we believe that this model has the potential to study the dysplasia cancer sequence in inflammatory disease.


Assuntos
Colite/induzido quimicamente , Colite/patologia , Sulfato de Dextrana , Animais , Colite/fisiopatologia , Colo/patologia , Feminino , Camundongos , Camundongos Endogâmicos , Fatores de Tempo
10.
J Biol Chem ; 267(11): 7880-5, 1992 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-1348509

RESUMO

It has been reported previously (Turner, P.M., and Lorand, L. (1989) Biochemistry 28, 628-635) that human erythrocyte transglutaminase forms a noncovalent complex with human plasma fibronectin near its collagen-binding domain. In the present study, we show by nondenaturing electrophoresis that guinea pig liver transglutaminase, similarly to the erythrocyte enzyme, forms a complex with human fibronectin. Studies of anisotropic shifts of fluorescein-labeled liver and erythrocyte transglutaminases, upon addition of fibronectin, indicated that both transglutaminases bind to fibronectin with a stoichiometry of about 2:1. Polymerization of fibrinogen by human erythrocyte transglutaminase was inhibited after complex formation with fibronectin. Complexes of fibronectin with either erythrocyte or liver transglutaminase were isolated by glycerol gradient zone sedimentation and examined by rotary shadowing electron microscopy. The globular transglutaminase could be readily identified binding to the thin fibronectin strand. The binding site for transglutaminase was within 5-10 nm of the N terminus of fibronectin, consistent with its proximity to the collagen-binding domain. Under some experimental conditions, the complex of fibronectin with erythrocyte transglutaminase appeared as a ring-shaped structure in which two transglutaminase molecules had probably dimerized. The molecular weight of the erythrocyte transglutaminase was determined by sedimentation equilibrium to be 71,440 +/- 830.


Assuntos
Fibronectinas/metabolismo , Transglutaminases/metabolismo , Animais , Reagentes de Ligações Cruzadas , Eletroforese em Gel de Poliacrilamida , Eritrócitos/enzimologia , Fibronectinas/isolamento & purificação , Fibronectinas/ultraestrutura , Polarização de Fluorescência , Cobaias , Humanos , Fígado/enzimologia , Microscopia Eletrônica , Coloração pela Prata , Especificidade da Espécie , Transglutaminases/isolamento & purificação , Transglutaminases/ultraestrutura , Células Tumorais Cultivadas
11.
Bioconjug Chem ; 3(1): 37-41, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1352131

RESUMO

Biotinylated peptides Biot-Gln-Gln-Ile-Val and Biot-epsilon-Aca-Gln-Gln-Ile-Val were shown to act as acceptor substrates for amines in reactions catalyzed by both tissue transglutaminase and coagulation factor XIIIa. Moreover, the peptides could be employed for specifically blocking the potential amine donor sites of protein substrates participating in biological cross-linking with these enzymes. The presence of the biotin label allowed for ready detectability of the marked donor substrates during the cross-linking of crystallins in lens homogenate by the intrinsic transglutaminase and that of the alpha chains of human fibrin by factor XIIIa.


Assuntos
Reagentes de Ligações Cruzadas , Glutamina/metabolismo , Peptídeos/metabolismo , Transglutaminases/metabolismo , Aminas/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Biotina , Cristalinas/química , Cristalinas/metabolismo , Fibrina/química , Fibrina/metabolismo , Humanos , Dados de Sequência Molecular , Peptídeos/química , Transglutaminases/química
12.
Peptides ; 12(1): 63-9, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2052500

RESUMO

A newly developed system of isolated rat colonic epithelial cells was utilized for a comprehensive study of protein synthesis influenced by gastrin. We found that synthetic human gastrin (0.01-100 nM) increased the incorporation of [35S]methionine into proteins within 2 hours. Peak incorporation was observed with 10 nM gastrin to more than two-fold above maintenance levels. Actinomycin-D (10 micrograms/ml) inhibited the stimulated increases in total protein synthesis indicating that the peptide's trophic effect was mediated by the synthesis of new mRNA species. The effect of gastrin was comparably stronger than the one induced by the mitogen bombesin (1 nM). However, bombesin, a neuromodulator of gastrin release, did not produce an additive effect beyond that of gastrin on total protein synthesis. Gastrin stimulated the synthesis of many polypeptides resolved on two-dimensional polyacrylamide gel, an indicator of gastrin's influence on the expression of various mRNA species. Some of these polypeptides may be used as markers in investigating colonic epithelial response to gastrin.


Assuntos
Colo/metabolismo , Gastrinas/fisiologia , Mucosa Intestinal/metabolismo , RNA Mensageiro/biossíntese , Animais , Bombesina/metabolismo , Colo/citologia , Regulação da Expressão Gênica/fisiologia , Técnicas In Vitro , Mucosa Intestinal/citologia , Masculino , Biossíntese Peptídica , Biossíntese de Proteínas , Ratos , Ratos Endogâmicos , Transcrição Gênica/genética
13.
Eur J Nucl Med ; 16(12): 847-53, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2209654

RESUMO

Eleven patients with proven primary bone tumour (five Ewing sarcomas, six osteosarcomas) and two cases of metastatic bone involvement (primary other than bone) were investigated with 99mTc-phytate and 99mTc-sulphur colloid to compare the behaviour of the two radiopharmaceuticals at the tumour site. After intravenous administration of the respective radiopharmaceutical, imaging of the tumour site and its contralateral part was carried out at 15 min and 1 h intervals. The data were stored in our computer. Bone scanning was also carried out in all patients. 99mTc-phytate uptake was observed at the tumour site in ten cases. The 99mTc-sulphur colloid study revealed sparse or no significant uptake in eight cases. In two patients, with osteosarcoma 99mTc-sulphur colloid investigation showed uptake at the primary tumour site. However, the distribution pattern is different from that of 99mTc-phytate. No significant uptake of either 99mTc-phytate or 99mTc-sulphur colloid was observed in the two patients with metastatic skeletal disease. It may be concluded that the unusual accumulation of 99mTc-phytate at the tumour site is not due to any generalized reticuloendothelial phenomenon and that the radiopharmaceutical itself is responsible for this.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Compostos de Organotecnécio , Osteossarcoma/diagnóstico por imagem , Ácido Fítico , Sarcoma de Ewing/diagnóstico por imagem , Coloide de Enxofre Marcado com Tecnécio Tc 99m , Adolescente , Adulto , Neoplasias Ósseas/secundário , Feminino , Humanos , Masculino , Cintilografia
14.
Eur J Nucl Med ; 15(3): 162-4, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2714301

RESUMO

During routine liver spleen scintigraphic studies using 99mTc-phytate in patients with proven osteosarcoma, an unusual uptake of this radiopharamaeutical at the primary site was observed. In all, five cases have been investigated and we have observed the uptake of 99mTc-phytate at the primary tumor site. Early and delayed imaging showed persistant concentration of the radiopharmaceutical. Studies with 99mTc-sulfur colloid in one of the patients did not show any uptake at the tumor site.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Compostos Organometálicos , Compostos de Organotecnécio , Osteossarcoma/diagnóstico por imagem , Ácido Fítico , Tecnécio , Adulto , Neoplasias Ósseas/secundário , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Cintilografia
15.
Peptides ; 9(3): 583-8, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3047699

RESUMO

We have compared the effects of the secretin family of peptides and their synthetic fragments on gastric emptying (GE) and small intestinal transit (SIT) using an unanesthetized rat model which simultaneously measures the GE and SIT of both solids and liquids. The meal consisting of 5% polyethylene glycol w/v, 5% Indian ink v/v and 20 non-digestible plastic beads was given intragastrically 10 minutes after the intraperitoneal injection of 0.5 ml of saline or peptides (2 and 5 micrograms/kg). Plasma secretin and the immunospecificity of secretin fragments were determined. In control rats, the t1/2 for the GE of both solids and liquids were 56 +/- 3.8 and 19 +/- 2.3 minutes, respectively. Liquids emptied faster than the solids and liquids travelled ahead of the solids in the intestine. Secretin (5 micrograms/kg) inhibited GE of both solids and liquids by 33-37%. Secretin delayed the SIT of the meal by approximately 35%. Fragments of secretin and of VIP had no effect on GE and SIT of both solids and liquids. The whole molecule of secretin was required to inhibit GE and to delay SIT of solids and liquids. Glucagon, PHI and growth hormone releasing factor (GHRF1-44) inhibited GE and SIT of both solids and liquids. For all peptides tested, the inhibition of SIT was proportional to the inhibition of GE suggesting that the prolongation of SIT was secondary to delayed GE. These observations indicate that the peptides of the secretin family inhibit GE and prolong SIT. Thus, the structural requirement required for the secretin family of peptides to effect their motor actions on the stomach is similar to that required for pancreatic enzyme secretion.


Assuntos
Esvaziamento Gástrico/efeitos dos fármacos , Hormônios Gastrointestinais/farmacologia , Trânsito Gastrointestinal/efeitos dos fármacos , Intestino Delgado/fisiologia , Secretina/farmacologia , Animais , Glucagon/farmacologia , Hormônio Liberador de Gonadotropina/farmacologia , Intestino Delgado/efeitos dos fármacos , Masculino , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos Endogâmicos , Secretina/sangue , Fatores de Tempo , Peptídeo Intestinal Vasoativo/farmacologia
16.
J Vasc Surg ; 5(6): 862-8, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3586183

RESUMO

Endothelial damage after simulated angioscopic insertion was evaluated in 22 dogs by radioimmunoassay of endogenous 6-keto-prostaglandin F1 alpha (stable product of prostacyclin produced by the endothelium) by means of a closed perfusion system and scanning electron microscopy. In 20 dogs, a 1.7 mm diameter polyethylene tube similar in size and physical characteristics to a commercially available angioscope was passed once into the distal venotomy site and out of the proximal venotomy site for a total distance of 15 cm in the left saphenous vein (group A) and 10 times in both directions in the right saphenous vein, destroying all valves (group B). The vein segments were examined immediately after simulated angioscopic insertion and at intervals of 2, 3, and 4 weeks. The remaining two dogs were used as control animals to establish baseline prostacyclin production. All veins were patent when harvested. Scanning electron microscopy revealed globular and contracted endothelial cells in some areas of group A veins, whereas partial longitudinal absence of endothelial cells was noted in group B veins. Intimal coverage was complete by 2 weeks in group A veins and between 3 and 4 weeks in group B veins. Prostacyclin synthesis of group B veins was significantly less than that of group A at day 1 and at 2 weeks after operation (p less than 0.05), reaching that of control vein synthesis by 4 weeks. This study suggests that simulated angioscopic trauma of the luminal surface of the canine saphenous vein had no negative effect on early patency.


Assuntos
Endoscopia/efeitos adversos , Veia Safena/lesões , 6-Cetoprostaglandina F1 alfa/análise , 6-Cetoprostaglandina F1 alfa/biossíntese , Animais , Cães , Endoscopia/métodos , Endotélio/metabolismo , Endotélio/ultraestrutura , Microscopia Eletrônica de Varredura , Perfusão/métodos , Radioimunoensaio , Veia Safena/metabolismo , Veia Safena/ultraestrutura , Fatores de Tempo
17.
Peptides ; 7(2): 357-63, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-2426687

RESUMO

We examined the effects of cyclic nucleotides and calcium on secretin release from canine duodenal mucosal explants incubated in organ culture media. Time course studies revealed that at pH 7.4, 5 and 10 mM dibutyryl cyclic adenosine monophosphate (DBcAMP) increased secretin release progressively, reaching a peak at 2 hours. Two mM of DBcAMP at pH 7.4 did not increase secretin release but at pH 4.5, all 3 doses potentiated secretin release. DBcAMP-stimulated secretin release was not dependent on the influx of extracellular calcium. Graded doses of 3-isobutyl-1-methylxanthine (IBMX) did not stimulate secretin secretion but 1 mM IBMX with 2 mM DBcAMP increased secretin secretion significantly. Dibutyryl cyclic guanosine monophosphate, cholera toxin and 5'-guanylyl-imidodiphosphate (GPP(NH)p) did not stimulate basal secretion release. The release of secretin from our explants incubated at pH 7.4 was not due to specific leakage because all of our viability studies revealed that our explants were functionally intact at the end of 2 hours. Our observations suggest that cyclic nucleotides may participate in the intracellular regulation of secretin secretion.


Assuntos
Bucladesina/farmacologia , GMP Cíclico/análogos & derivados , Dibutiril GMP Cíclico/farmacologia , Duodeno/metabolismo , Mucosa Intestinal/metabolismo , Secretina/metabolismo , 1-Metil-3-Isobutilxantina/farmacologia , Adenilil Ciclases/metabolismo , Animais , Cálcio/farmacologia , Sobrevivência Celular , AMP Cíclico/metabolismo , Cães , Duodeno/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Cinética , Técnicas de Cultura de Órgãos
18.
J Biol Chem ; 257(3): 1438-42, 1982 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-7056725

RESUMO

Band 3, the anion transport protein of the human erythrocyte, provides the site of association of certain glycolytic enzymes with the membrane. We have now demonstrated that glyceraldehyde-3-P dehydrogenase is inhibited, reversibly and completely, when membrane bound. The inhibition was competitive with respect to NAD+ and arsenate, but was noncompetitive with glyceraldehyde-3-P. Peptide fragments containing the NH2-terminal 23 residues of band 3 also inhibited the enzyme and displaced it from ghosts. Thus, the red cell membrane binding site for glyceraldehyde-3-P dehydrogenase is the same as that for aldolase, the polyanionic NH2-terminal region of the band 3 polypeptide.


Assuntos
Proteínas Sanguíneas/metabolismo , Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/sangue , Proteína 1 de Troca de Ânion do Eritrócito , Ânions , Humanos , Cinética , Concentração Osmolar , Ligação Proteica
19.
J Biol Chem ; 256(21): 11203-8, 1981 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-7287763

RESUMO

Band 3 is the predominant membrane-spanning polypeptide and the mediator of anion transport in the human erythrocyte. In addition, it provides the sites of association for fructose 1,6-bisphosphate aldolase and other cytoplasmic proteins with the membrane. The aldolase-binding activity of water-soluble fragments of band 3 was measured by their inhibition of aldolase catalytic activity and by their displacement of aldolase from ghosts. At saturation, the binding of one band 3 or certain of its fragments per aldolase molecule partially inhibited the catalytic activity and band 3 binding of the unliganded subunits of the tetramer through an apparently cooperative mechanism. An NH2-terminal 23,000-dalton fragment generated by S-cyanylation of the cytoplasmic pole of band 3 was approximately 20% as avid in binding aldolase as was native band 3. Several fragments cleaved from the NH2-terminal portion of the 23,000-dalton peptide by trypsin, mild acid hydrolysis, and cyanogen bromide digestion all bound aldolase, while fragments from the rest of the polypeptide were essentially inactive. The first 31 residues of band 3 contained 16 Asp plus Glu, no basic residues, and a blocked alpha-amino terminus. The highly acidic composition of this region is consistent with the strongly electrostatic character of the interaction between band 3 and aldolase, presumably at the strongly basic catalytic center of the enzyme. We conclude that the NH2-terminal region of band 3 bears the membrane-binding site for aldolase.


Assuntos
Proteínas Sanguíneas/metabolismo , Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , Frutose-Bifosfato Aldolase/sangue , Proteínas de Membrana/metabolismo , Aminoácidos/análise , Proteína 1 de Troca de Ânion do Eritrócito , Sítios de Ligação , Frutose-Bifosfato Aldolase/antagonistas & inibidores , Humanos , Cinética , Músculos/enzimologia , Ligação Proteica
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