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1.
Trans R Soc Trop Med Hyg ; 100(11): 1007-12, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16765392

RESUMO

Plasmodium falciparum infection may result in severe malaria in susceptible individuals. The pathogenesis of severe disease is probably a combination of the sequestration of infected erythrocytes and overstimulation of the immune response. Monocytes are a key source of many of the pro-inflammatory agents implicated but also are found sequestered in blood vessels. However, little is known about the monocyte phenotype in malaria disease. Flow cytometry was performed on fresh whole blood to determine surface expression of four receptors during acute severe and non-severe malaria and again during convalescence when uninfected. Three hundred and fifty-six children with P. falciparum infection were studied and were found to show increased expression of intercellular adhesion molecule-1 (ICAM-1), urokinase plasminogen activator receptor (uPAR), CD23 and chemokine receptor 5 (CCR5) (P<0.001) during acute disease compared with convalescent levels. Using multivariate analysis, it was found that large increases in expression of ICAM-1 (odds ratio (OR) 2.44, 95% CI 1.80-3.32) and uPAR (OR 3.14, 95% CI 1.93-5.09) but small increases in expression of CD23 (OR 0.82, 95% CI 0.68-0.96) were independently associated with severe malaria. These results give an insight into the cellular processes occurring in severe malaria and suggest that pathology is based on a complex repertoire of pro- and anti-inflammatory processes.


Assuntos
Malária Falciparum/metabolismo , Proteínas de Membrana/metabolismo , Monócitos/metabolismo , Criança , Pré-Escolar , Citometria de Fluxo , Humanos , Lactente , Recém-Nascido , Malária Falciparum/parasitologia , Monócitos/parasitologia , Fenótipo
2.
Gut ; 52(3): 352-7, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12584215

RESUMO

INTRODUCTION: Sphincter of Oddi (SO) manometry is at present the "gold standard" investigation for patients with suspected biliary SO dysfunction. Non-invasive scintigraphy in cholecystectomised patients using a complex scoring system or the transit time from the hepatic hilum to the duodenum (HDTT) have been promoted as sensitive and specific alternatives. AIM: To evaluate the scintigraphic scoring system and HDTT in patients with suspected biliary SO dysfunction undergoing SO manometry. METHODS: Cholecystectomised patients undergoing SO manometry for persistent biliary-type pain, as defined by the Rome II criteria, for which all other causes had been excluded, were prospectively studied. Scintigraphy with cholecystokinin octapeptide infusion was performed within a month prior to manometry. Scoring of the scans and measurement of HDTT was performed by independent blinded observers. Manometry of the biliary sphincter was performed per-endoscopically and defined as abnormal if basal pressure was > or = 40 mm Hg. RESULTS: Thirty two patients were enrolled (30 females, mean age 45.1 years). Three patients were excluded from analysis because manometry from the bile duct was not technically possible. Eight patients had abnormal manometry. Scintigraphic scoring had a sensitivity of 25-38%, a specificity of 86-89%, positive predictive value (PPV) of 40-60%, and a negative predictive value (NPV) of 75-79%. The coefficient of variation for interobserver variation in scores was 0.72. HDTT sensitivity was 13%, specificity 95%, PPV 50%, and NPV 74%. CONCLUSIONS: Our findings indicate that scintigraphy using these methods of analysis correlates poorly with manometry in post cholecystectomy patients with suspected biliary SO dysfunction.


Assuntos
Doenças do Ducto Colédoco/diagnóstico , Síndrome Pós-Colecistectomia/diagnóstico , Esfíncter da Ampola Hepatopancreática/fisiopatologia , Adulto , Idoso , Doenças do Ducto Colédoco/diagnóstico por imagem , Feminino , Humanos , Masculino , Manometria , Pessoa de Meia-Idade , Variações Dependentes do Observador , Síndrome Pós-Colecistectomia/diagnóstico por imagem , Valor Preditivo dos Testes , Pressão , Estudos Prospectivos , Cintilografia , Sensibilidade e Especificidade , Sincalida , Esfíncter da Ampola Hepatopancreática/diagnóstico por imagem
3.
Dig Dis Sci ; 47(9): 2029-36, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12353851

RESUMO

Nifedipine is used to treat sphincter of Oddi dysfunction. Its effects on the biliary system and duodenum in relation to its known vascular actions are unclear. Our aims were to determine the relative tissue sensitivities to dihydropyridine L-type calcium channel antagonism in the sphincter of Oddi, gallbladder, duodenum, and vasculature. For in vivo studies, 23 possums received nifedipine at three different doses with blood pressure and sphincter of Oddi manometry recordings. For in vitro studies, tissues from 28 possums were pretreated with nicardipine (10(-8)-10(-5) M) and cumulative concentrations of agonist were administered (carbachol, norepinephrine at 10(-9)-10(-5) M). In in vivo studies, blood pressure fell significantly at a lower dose than sphincter of Oddi motility. In in vitro studies, the sphincter of Oddi was more sensitive than arterial tissue, with the duodenum especially sensitive. In conclusion, in the possum we found that L-type channel antagonism in vivo was more potent to the vasculature than the sphincter of Oddi but this was not confirmed in vitro.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/efeitos dos fármacos , Duodeno/efeitos dos fármacos , Vesícula Biliar/efeitos dos fármacos , Nifedipino/farmacologia , Gambás , Esfíncter da Ampola Hepatopancreática/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Agonistas dos Canais de Cálcio/farmacologia , Feminino , Masculino , Manometria , Nicardipino/farmacologia
5.
Toxicon ; 40(4): 401-7, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11738233

RESUMO

A novel Conus peptide, conorfamide-Sr1, has been characterized. The sequence of the natural peptide was determined using standard Edman sequencing methods and mass spectrometry, and confirmed by chemical synthesis. The peptide has 12 amino acids and no cysteine residues. The following sequence was obtained: GPMGWVPVFYRF-NH(2). No other peptide from a vermivorous Atlantic Conus species has previously been characterized. Conorfamide-Sr1 belongs to the RFamide neuropeptide family, and is the first RFamide peptide to be found in any venom. The presence of conorfamide-Sr1 as a major peptide in Conus spurius venom suggests that Conus lineages in the Atlantic may have evolved novel Conus venom peptide families.


Assuntos
Venenos de Moluscos/química , Peptídeos/química , Sequência de Aminoácidos , Animais , Evolução Biológica , Espectrometria de Massas , Dados de Sequência Molecular , Neuropeptídeos/química
6.
Cochrane Database Syst Rev ; (3): CD001509, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11686993

RESUMO

BACKGROUND: The sphincter of Oddi regulates both bile and pancreatic juice flow into the duodenum. When dysfunction occurs it leads to problems relating to either the bile or pancreatic ducts. On the biliary side, the most common problem is recurrent biliary type pain following cholecystectomy. OBJECTIVES: Is sphincterotomy effective treatment for biliary sphincter of Oddi dysfunction patients? SEARCH STRATEGY: Electronic data bases, including the Collaborative Review Group trial registers, MEDLINE, and EMBASE, as well as checking reference lists in as many languages as possible that had the titles: sphincter of Oddi dysfunction, biliary dyskinesia, papillary stenosis, biliary dyssynergia, odditis, papillitis, post-cholecystectomy pain, right upper quadrant pain, or unexplained right upper quadrant pain were included. These titles were matched with sphincterotomy. SELECTION CRITERIA: Randomised placebo-controlled trials performing sphincterotomy in patients with suspected biliary sphincter of Oddi dysfunction using manometry as part of the patient evaluation. A basal pressure > 40 mmHg was defined as abnormal. The primary outcome measure were symptomatic response (defined either as cure/improvement or not improved) to sphincterotomy. DATA COLLECTION AND ANALYSIS: Electronic data bases were used to search for the studies. Studies were attempted to be stratified as randomised clinical trials, controlled clinical trials (i.e., quasi-randomised clinical trials), well designed observational studies using a well matched control group, or other. These groupings were then entered into a meta-analysis. MAIN RESULTS: Only two randomised clinical trials met the inclusion criteria. In 49 patients studied, sphincterotomy was more effective than placebo in treating patients with an elevated basal pressure (Peto odds ratio 9.08, 95% confidence interval 2.97-277.77). In 77 patients studied, sphincterotomy was no better than placebo in treating patients with a normal normal basal pressure (Peto odds ratio 1.28, 95% confidence interval 0.52-3.13). There was no data on quality of life or health economics. REVIEWER'S CONCLUSIONS: These results suggest that sphincterotomy for biliary sphincter of Oddi dysfunction appears effective in those patients with an elevated sphincter of Oddi basal pressure (>40 mmHg), but is no better than placebo in those patients with a normal basal pressure. The results reported in this review must be interpreted with caution as there are only two studies and one of the reviewers (Toouli) has been an author in both studies. Further trials by independent groups are recommended.


Assuntos
Doenças do Ducto Colédoco/cirurgia , Esfíncter da Ampola Hepatopancreática/cirurgia , Intervalos de Confiança , Humanos , Razão de Chances , Ensaios Clínicos Controlados Aleatórios como Assunto
8.
Neuroendocrinology ; 74(3): 202-12, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11528222

RESUMO

Rat and hamster brain tissues were used to investigate the possible existence of a follicle stimulating hormone (FSH)-releasing factor with similar characteristics to the lamprey gonadotropin-releasing hormone III (lGnRH-III) form proposed in previous reports. The present studies involved isolation and purification of the molecule by high-performance liquid chromatography (HPLC), identification by radioimmunoassay, sequence analysis by automated Edman degradation, mass spectrometry and examination of biological activity. Hypothalamic extracts from both species contained an HPLC fraction that was immunoreactive to GnRH and coeluted with lGnRH-III and 9-hydroxyproline mGnRH ([Hyp(9)]GnRH). Determination of primary structure from purified total brain material demonstrated that the isolated molecule was [Hyp(9)]GnRH. This is the first report showing the presence of the posttranslationally modified form already known as [Hyp(9)]GnRH by primary sequence analysis. The biological activity of distinct GnRH peptides was also tested in vitro for gonadotropin release using rat pituitary primary cell cultures. The results showed that [Hyp(9)]GnRH stimulated both luteinizing hormone and FSH release, as already reported, whereas lGnRH-III had no action on the secretion of either gonadotropin.


Assuntos
Encéfalo/metabolismo , Hormônio Liberador de Gonadotropina/química , Hormônio Liberador de Gonadotropina/farmacologia , Sequência de Aminoácidos/genética , Animais , Cricetinae , Feminino , Hormônio Foliculoestimulante/metabolismo , Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Liberador de Gonadotropina/genética , Hormônio Liberador de Gonadotropina/isolamento & purificação , Hidroxiprolina/análogos & derivados , Hidroxiprolina/farmacologia , Hipotálamo/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Espectrometria de Massas , Mesocricetus , Hipófise/citologia , Hipófise/metabolismo , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/isolamento & purificação , Isoformas de Proteínas/farmacologia , Ratos , Relação Estrutura-Atividade
9.
Endoscopy ; 33(8): 651-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11490379

RESUMO

BACKGROUND AND STUDY AIMS: Unavoidable catheter movement during sphincter of Oddi (SO) manometry can produce considerable variations in the basal pressure, due to movement of the recording sidehole. The sleeve sensor is a perfused channel which records the highest pressure point along its length. The aim of the study was to develop and evaluate a prototype sleeve sensor for SO manometry. MATERIALS AND METHODS: Bench-testing was used to assess the dynamic performance of the sleeve and sidehole assemblies. Recordings were initially made with a standard triple-lumen catheter and then with a purpose-built manometric assembly which had a 15 mm long sleeve sensor. RESULTS: A perfusion rate of 0.04 ml/min gave the best balance between baseline pressure offset and rise rate. Recordings were attempted in nine patients and successfully achieved in four. The sleeve and sidehole recordings of the maximal basal pressure did not differ significantly (mean +/- SEM, 86.1 +/- 26.5 mmHg vs. 90.1 +/- 21.0 mmHg, P = 0.57, r = 0.998). CONCLUSIONS: Unnecessarily high perfusion rates are being used for SO manometry. The sleeve sensor has the potential to monitor SO pressure more reliably than the currently used perfused sidehole method and should enhance the safety of prolonged SO manometry.


Assuntos
Desenho de Equipamento , Manometria/instrumentação , Movimento/fisiologia , Esfíncter da Ampola Hepatopancreática/fisiologia , Adulto , Desenho de Equipamento/tendências , Feminino , Humanos , Masculino , Manometria/métodos , Manometria/estatística & dados numéricos , Pessoa de Meia-Idade , Perfusão
10.
J Biol Chem ; 276(40): 37621-9, 2001 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-11448959

RESUMO

Many cell types mount elaborate, compensatory responses to stress that enhance survival; however, the intracellular signals that govern these responses are poorly understood. Cardiotrophin-1 (CT-1), a stress-induced cytokine, belongs to the interleukin-6/glycoprotein 130 receptor-coupled cytokine family. CT-1 is released from the heart in response to hypoxic stress, and it protects cardiac myocytes from hypoxia-induced apoptosis, thus establishing a central role for this cytokine in the cardiac stress response. In the present study, CT-1 activated p38 and ERK MAPKs as well as Akt in cultured cardiac myocytes; these three pathways were activated in a parallel manner. CT-1 also induced the degradation of the NF-kappa B cytosolic anchor, I kappa B, as well as the translocation of the p65 subunit of NF-kappa B to the nucleus and increased expression of an NF-kappa B-dependent reporter gene. Inhibitors of the p38, ERK, or Akt pathways each partially reduced CT-1-mediated NF-kappa B activation, as well as the cytoprotective effects of CT-1 against hypoxic stress. Together, the inhibitors completely blocked CT-1-dependent NF-kappa B activation and cytoprotection. A cell-permeable peptide that selectively disrupted NF-kappa B activation also completely inhibited the cytoprotective effects of CT-1. These results indicate that CT-1 signals through p38, ERK, and Akt in a parallel manner to activate NF-kappa B and that NF-kappa B is required for CT-1 to mediate its full cytoprotective effects in cardiac myocytes.


Assuntos
Citocinas/farmacologia , Miocárdio/metabolismo , NF-kappa B/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Hipóxia Celular , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Proteínas I-kappa B/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Miocárdio/citologia , NF-kappa B/genética , Fosfatidilinositol 3-Quinases/metabolismo , Substâncias Protetoras/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Transcrição Gênica/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno
11.
J Med Chem ; 44(13): 2238-46, 2001 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-11405660

RESUMO

A family of analogues of des-AA(1,2,5)-[DTrp(8)/D2Nal(8)]-SRIF that contain a 4-(N-isopropyl)-aminomethylphenylalanine (IAmp) at position 9 was identified that has high affinity and selectivity for human somatostatin receptor subtype 1 (sst1). The binding affinities of des-AA(1,2,5)-[DTrp(8),IAmp(9)]-SRIF (c[H-Cys-Lys-Phe-Phe-DTrp-IAmp-Thr-Phe-Thr-Ser-Cys-OH], CH-275) (7), des-AA(1,5)-[Tyr(2),DTrp(8),IAmp(9)]-SRIF (CH-288) (16), des-AA(1,2,5)-[Tyr(7),DTrp(8),IAmp(9)]-SRIF (23), and des-AA(1,2,5)-[DTrp(8),IAmp(9),Tyr(11)]-SRIF (25) are about (1)/(7), (1)/(4), (1)/(125), and (1)/(4) that of SRIF-28 (1) to sst1, respectively, about (1)/(65), (1)/(130), <(1)/(1000), and <(1)/(150) that of 1 to sst3, respectively, and about or less than (1)/(1000) that of 1 to the other three human SRIF receptor subtypes. A substitution of DTrp(8) by D2Nal(8) in 7 to yield des-AA(1,2,5)-[D2Nal(8),IAmp(9)]-SRIF (13) and in 16 to yield des-AA(1,5)-[Tyr(2),D2Nal(8),IAmp(9)]-SRIF (17) was intended to increase chemical stability, selectivity, and affinity and resulted in two analogues that were less potent or equipotent with similar selectivity, respectively. Carbamoylation of the N-terminus as in des-AA(1,2,5)-[DTrp(8),IAmp(9),Tyr(11)]-Cbm-SRIF (27) increased affinity slightly as well as improved selectivity. Monoiodination of 25 to yield 26 and of 27 to yield 28 resulted in an additional 4-fold increase in affinity at sst1. Desamination of the N-terminus of 17 to yield 18, on the other hand, resulted in significant loss of affinity. Attempts at reducing the size of the ring with maintenance of selectivity failed in that des-AA(1,4,5,13)-[Tyr(2),DTrp(8),IAmp(9)]-SRIF (33) and des-AA(1,4,5,6,12,13)-[Tyr(2),DTrp(8),IAmp(9)]-SRIF (34) progressively lost affinity for all receptors. Both des-AA(1,2,5)-[DTrp(8),IAmp(9),Tyr(11)]-Cbm-SRIF (27) and des-AA(1,2,5)-[DCys(3),DTrp(8),IAmp(9),Tyr(11)]-Cbm-SRIF (29) show agonistic activity in a cAMP assay; therefore, the structural basis for the agonist property of this family of analogues is not contingent upon the chirality of the Cys residue at position 3 as shown to be the case in 18-membered ring SRIF octapeptides. None of the high affinity structures described here showed receptor antagonism. We have prepared the radiolabeled des-AA(1,2,5)-[DTrp(8),IAmp(9),(125)ITyr(11)]-SRIF ((125)I-25) and des-AA(1,2,5)-[DTrp(8),IAmp(9), (125)ITyr(11)]-Cbm-SRIF ((125)I-27), used them as in vitro tracers, and found them to be superior to des-AA(1,5)-[(125)ITyr(2),DTrp(8),IAmp(9)]-SRIF ((125)I-16) for the detection of sst1 tumors in receptor autoradiography studies.


Assuntos
Receptores de Somatostatina/agonistas , Somatostatina/análogos & derivados , Somatostatina/agonistas , Somatostatina/síntese química , Adenilil Ciclases/metabolismo , Animais , Autorradiografia , Células CHO , Cricetinae , Feminino , Humanos , Hibridização In Situ , Leiomioma/metabolismo , Conformação Molecular , Ligação Proteica , Proteínas Recombinantes/metabolismo , Somatostatina/química , Somatostatina/farmacologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Neoplasias Uterinas/metabolismo
12.
J Biol Chem ; 276(34): 31528-34, 2001 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-11425856

RESUMO

The first extracellular domain (ECD-1) of the corticotropin releasing factor (CRF) type 1 receptor, (CRFR1), is important for binding of CRF ligands. A soluble protein, mNT-CRFR1, produced by COS M6 cells transfected with a cDNA encoding amino acids 1--119 of human CRFR1 and modified to include epitope tags, binds a CRF antagonist, astressin, in a radioreceptor assay using [(125)I-d-Tyr(0)]astressin. N-terminal sequencing of mNT-CRFR1 showed the absence of the first 23 amino acids of human CRFR1. This result suggests that the CRFR1 protein is processed to cleave a putative signal peptide corresponding to amino acids 1--23. A cDNA encoding amino acids 24--119 followed by a FLAG tag, was expressed as a thioredoxin fusion protein in Escherichia coli. Following thrombin cleavage, the purified protein (bNT-CRFR1) binds astressin and the agonist urocortin with high affinity. Reduced, alkylated bNT-CRFR1 does not bind [(125)I-D-Tyr(0)]astressin. Mass spectrometric analysis of photoaffinity labeled bNT-CRFR1 yielded a 1:1 complex with ligand. Analysis of the disulfide arrangement of bNT-CRFR1 revealed bonds between Cys(30) and Cys(54), Cys(44) and Cys(87), and Cys(68) and Cys(102). This arrangement is similar to that of the ECD-1 of the parathyroid hormone receptor (PTHR), suggesting a conserved structural motif in the N-terminal domain of this family of receptors.


Assuntos
Hormônio Liberador da Corticotropina/genética , Sequência de Aminoácidos , Animais , Células COS , Dicroísmo Circular , Hormônio Liberador da Corticotropina/química , Hormônio Liberador da Corticotropina/isolamento & purificação , DNA Complementar , Humanos , Dados de Sequência Molecular , Solubilidade
13.
J Am Soc Mass Spectrom ; 12(4): 470-4, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11322194

RESUMO

During our characterization of plicatamide 1, a modified octapeptide: Phe-Phe-His-Leu-His-Phe-His-dc deltaDOPA (where dc deltaDOPA = decarboxy-(E)-alpha,beta-dehydro-3,4-dihydroxyphenylalanine) from the blood cells of the ascidian Styela plicata, we noted a series of fragment ions from the [M + H]+ ion which could not be assigned. There was no evidence in the 1H NMR spectrum to support an alternative molecular structure and the series of fragment ions were not present in the tandem mass spectrometry analysis of the [M + Na]+ ion. In addition, there was no evidence that the sample was a mixture of isobaric compounds. We propose that an unusual C-terminal to N-terminal rearrangement is responsible for the series of fragment ions from the [M + H]+ ion. This rearrangement was not observed in peptide analogs of plicatamide which did not contain the dc deltaDOPA at the C-terminus suggesting that this moiety is critical for the rearrangement. The proposed reaction is analogous to that recently reported by Vachet et al. involving a fragment ion formed from leucine enkephalin.


Assuntos
Oligopeptídeos/química , Urocordados/química , Animais , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Oligopeptídeos/sangue , Espectrometria de Massas por Ionização por Electrospray
14.
Endocrinology ; 142(4): 1453-60, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11250925

RESUMO

The neuropeptide GnRH is the major regulator of reproduction in vertebrates acting as a first signal from the hypothalamus to pituitary gonadotropes. Three GnRH molecular variants were detected in the brain of a fish, pejerrey (Odontesthes bonariensis), using chromatographic and immunological methods. The present study shows that one form is identical to chicken GnRH-II (sequence analysis and mass spectrometry) and the second one is immunologically and chromatographically similar to salmon GnRH. The third form was proven to be a novel form of GnRH by isolating the peptide from the brain and determining its primary structure by chemical sequencing and mass spectrometry. The sequence of the novel pejerrey GnRH is pGlu-His-Trp-Ser-Phe-Gly-Leu-Ser-Pro-Gly-NH(2), which is different from the known forms of the vertebrate and protochordate GnRH family. The new form of GnRH is biologically active in releasing gonadotropin and GH from pituitary cells in an in vitro assay.


Assuntos
Química Encefálica , Peixes/metabolismo , Hormônio Liberador de Gonadotropina/química , Aminoácidos/análise , Animais , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Hormônio Liberador de Gonadotropina/síntese química , Hormônio Liberador de Gonadotropina/farmacologia , Peptídeos/síntese química , Peptídeos/química , Peptídeos/isolamento & purificação , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Radioimunoensaio , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
15.
J Gastroenterol Hepatol ; 16(2): 230-4, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11207909

RESUMO

The pathophysiology of choledochal cysts remains unclear, although an association with anomalous pancreato-biliary junction and the reflux of pancreatic enzymes into the biliary tree is known. Sphincter of Oddi (SO) manometry was performed in three patients with choledochal cysts. All patients exhibited an elevated basal pressure diagnostic of sphincter of Oddi dysfunction. Two patients exhibited anomalous pancreato-biliary junction. This report suggests an association between the choledochal cyst and sphincter of Oddi dysfunction, and may suggest that SO dysfunction plays a role in choledochal cyst formation.


Assuntos
Cisto do Colédoco/etiologia , Cisto do Colédoco/fisiopatologia , Doenças do Ducto Colédoco/fisiopatologia , Esfíncter da Ampola Hepatopancreática/fisiopatologia , Adulto , Austrália , China , Doenças do Ducto Colédoco/complicações , Feminino , Humanos , Pessoa de Meia-Idade
16.
Toxicon ; 39(6): 809-15, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11137540

RESUMO

We have determined that the mammalian uridine diphospho-N-acetyl-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase T1 (EC 2.4.1.41) has the appropriate acceptor substrate specificity to recognize the non-glycosylated form of contulakin-G (ZSEEGGSNATKKPYIL-OH where Z=pyroglutamic acid) and to transfer GalNAc to the peptide. Both [Thr(10)] contulakin-G and a pre-contulakin-G(30-66) (RGLVPDDITPQLILGSLISRRQSEEGGSNATKKPYIL-OH) were shown to be acceptors for the mammalian enzyme. The site of attachment of the GalNAc residue was determined using chemical and radioactive sequencing techniques. The mammalian enzyme was highly specific for Thr(10) residue, in which the native peptide was found to be glycosylated, compared with either Ser(2) or Ser(7). In the case of pre-contulakin-G, the enzyme was also highly specific for the equivalent threonine residue. These results suggest that the Cone snail uses an enzyme with similar acceptor specificity to that of the mammalian polypeptide N-acetylgalactosaminyltransferase for glycosylating contulakin-G.


Assuntos
Glicoproteínas/metabolismo , Venenos de Moluscos/metabolismo , N-Acetilgalactosaminiltransferases/metabolismo , Neuropeptídeos/metabolismo , Sequência de Aminoácidos , Animais , Glicoproteínas/química , Glicosilação , Mamíferos , Dados de Sequência Molecular , Venenos de Moluscos/química , Neuropeptídeos/química
18.
Am J Physiol Gastrointest Liver Physiol ; 279(4): G837-43, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11005772

RESUMO

Manometric assembly diameter is a major limitation on the number of perfused manometric recording points for recordings from the sphincter of Oddi (SO). We evaluated novel polyimide manometric assemblies whereby four recording channels were incorporated in an overall assembly diameter of 0.8 mm. Over the very low range of perfusion rates tested (0.005-0.04 ml/min), the assemblies had pressure offsets attributable to water perfusion from 2 to 23 mmHg and pressure rise rates from 20 to 163 mmHg/s. In six anesthetized Australian brush-tailed possums, manometric recordings from the SO showed a significant reduction in the recorded peak amplitude of pressure waves with perfusion rates below 0.02 ml/min. The pressure profile of the sphincter was found to be asymmetric, and phasic wave propagation patterns were complex (antegrade 35.6%, "mixed" 64.4%). In conclusion, accurate multipoint SO manometry in the possum can be performed with micromanometric assemblies at very low perfusion rates to give a more complete understanding of SO mechanics. These methods are also potentially applicable to perfusion manometry in other small laboratory animals such as mice.


Assuntos
Motilidade Gastrointestinal/fisiologia , Contração Muscular/fisiologia , Esfíncter da Ampola Hepatopancreática/fisiologia , Animais , Animais de Laboratório , Austrália , Manometria/instrumentação , Manometria/métodos , Camundongos , Gambás , Perfusão
19.
J Biol Chem ; 275(49): 38417-26, 2000 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-10978343

RESUMO

We isolated styelin D, a 32-residue, C-terminally amidated antimicrobial peptide, from the blood cells (hemocytes) of the solitary ascidian, Styela clava. Styelin D had remarkably extensive post-translational modifications, containing two novel amino acids, dihydroxyarginine and dihydroxylysine, and two distinctly unusual ones, 6-bromotryptophan and 3,4-dihydroxyphenylalanine. In addition, the peptide exhibited microheterogeneity because of differential mono- and dihydroxylation of several lysine residues. The primary sequence of one variant was: GW(*)LR(**)K(**)AAK(**)SVGK(**)FY(*)Y(*)K(**)HK(*)Y(*) Y(*)IK(*)AAWQIG KHAL-NH(2), where W(*) is 6-bromotryptophan, R(**) is dihydroxyarginine, Y(*) is 3,4-dihydroxyphenylalanine, K(*) is 5-hydroxylysine, and K(**) is dihydroxylysine. Styelin D exhibited activity against Gram-negative and Gram-positive bacteria, and this activity was retained in 200 mm NaCl. The role of the extensive modifications may be to preserve activity at low pH and/or high salinity because, under these conditions, the native peptide was considerably more active against the Gram-positive bacterial strains than its unmodified synthetic analogue. The peptide was also hemolytic and quite cytotoxic to eukaryotic cells. These broad ranging activities, combined with its relative abundance in ascidian hemocytes, suggest that styelin D plays a significant role in the innate immune mechanisms of S. clava.


Assuntos
Antibacterianos/química , Hemócitos/química , Proteínas/química , Urocordados , Sequência de Aminoácidos , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Di-Hidroxifenilalanina/análise , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Cromatografia Gasosa-Espectrometria de Massas , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Proteínas/isolamento & purificação , Proteínas/farmacologia , Triptofano/análogos & derivados , Triptofano/análise
20.
Proc Natl Acad Sci U S A ; 97(4): 1766-71, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10677532

RESUMO

Binding of infected erythrocytes to brain venules is a central pathogenic event in the lethal malaria disease complication, cerebral malaria. The only parasite adhesion trait linked to cerebral sequestration is binding to intercellular adhesion molecule-1 (ICAM-1). In this report, we show that Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) binds ICAM-1. We have cloned and expressed PfEMP1 recombinant proteins from the A4tres parasite. Using heterologous expression in mammalian cells, the minimal ICAM-1 binding domain was a complex domain consisting of the second Duffy binding-like (DBL) domain and the C2 domain. Constructs that contained either domain alone did not bind ICAM-1. Based on phylogenetic criteria, there are five distinct PfEMP1 DBL types designated alpha, beta, gamma, delta, and epsilon. The DBL domain from the A4tres that binds ICAM-1 is DBLbeta type. A PfEMP1 cloned from a distinct ICAM-1 binding variant, the A4 parasite, contains a DBLbeta domain and a C2 domain in tandem arrangement similar to the A4tres PfEMP1. Anti-PfEMP1 antisera implicate the DBLbeta domain from A4var PfEMP1 in ICAM-1 adhesion. The identification of a P. falciparum ICAM-1 binding domain may clarify mechanisms responsible for the pathogenesis of cerebral malaria and lead to interventions or vaccines that reduce malarial disease.


Assuntos
Molécula 1 de Adesão Intercelular/química , Malária Cerebral/parasitologia , Plasmodium falciparum/química , Proteínas de Protozoários/genética , Sequência de Aminoácidos , Animais , Anticorpos/farmacologia , Antígenos CD36/metabolismo , Células COS , Adesão Celular , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Clonagem Molecular , Eritrócitos/metabolismo , Malária Cerebral/metabolismo , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Ligação Proteica/genética , Proteínas de Protozoários/metabolismo , Proteínas Recombinantes , Alinhamento de Sequência , Transfecção
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